CN114761742B

CN114761742B - Control device for refrigeration cycle device, and refrigeration cycle device

Info

Publication number: CN114761742B
Application number: CN201980102602.9A
Authority: CN
Inventors: 松尾光晃; 石原宽也; 八代崇宪
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2019-12-04
Filing date: 2019-12-04
Publication date: 2024-04-30
Anticipated expiration: 2039-12-04
Also published as: JP7246518B2; WO2021111559A1; GB202205556D0; GB2604464A; CN114761742A; JPWO2021111559A1; GB2604464B

Abstract

The control device (110) is provided with a memory (112) and a CPU (111) for storing a target value of a physical quantity to be controlled. The CPU (111) is configured to execute the following processing: i) An abnormality detection process for detecting an abnormality of the electronic expansion valve (5) based on the physical quantity and a target value stored in a memory (112); ii) a valve operation confirmation process for, when an abnormality of the electronic expansion valve (5) is detected by the abnormality detection process, transmitting a command for changing the opening degree to the electronic expansion valve (5) and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) stopping the refrigeration cycle device (100, 200) when no change is observed in the physical quantity in the valve operation confirmation process.

Description

Control device for refrigeration cycle device, and refrigeration cycle device

Technical Field

The present invention relates to a control device for a refrigeration cycle apparatus and a refrigeration cycle apparatus.

Background

The failure detection of an electronic expansion valve used in a refrigeration cycle apparatus is disclosed in patent No. 3558182 (patent document 1). The refrigeration cycle device is provided with an abnormality detection means for monitoring whether or not an abnormality has occurred in the refrigeration cycle by inputting the temperature of each part of the refrigeration cycle, the outdoor temperature, and the indoor temperature.

Patent document 1: japanese patent No. 3558182

In the failure detection function of the electronic expansion valve described in japanese patent No. 3558182 (patent document 1), there is a possibility that the evaporator outlet superheat deviates from the normal range due to abrupt change in the heat load or temporary use outside the normal use range, and the failure detection may be abnormally stopped by erroneous detection.

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a control device for a refrigeration cycle apparatus, which reduces false detection of a failure of an electronic expansion valve, and a refrigeration cycle apparatus including the control device.

The present disclosure relates to a control device for a refrigeration cycle device equipped with an electronic expansion valve. The control device is provided with: a memory for storing a target value of a physical quantity to be controlled, and a control unit. The control unit is configured to execute: i) An abnormality detection process of detecting an abnormality of the electronic expansion valve based on the physical quantity and a target value stored in the memory; ii) a valve operation confirmation process of, when an abnormality of the electronic expansion valve is detected by the abnormality detection process, transmitting a command to change the opening degree to the electronic expansion valve, and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) stopping the refrigeration cycle apparatus when no change is observed in the physical quantity in the valve operation confirmation process.

According to the refrigeration cycle apparatus of the present disclosure, it is possible to avoid a situation in which an abnormality of the electronic expansion valve is erroneously detected and the refrigeration cycle apparatus is erroneously stopped.

Drawings

Fig. 1 is a configuration diagram showing the configuration of a refrigeration cycle apparatus according to embodiment 1.

Fig. 2 is a flowchart for explaining the periodic control of the various electronic expansion valves performed by the control device 110.

Fig. 3 is a flowchart for explaining control of the abnormality detection process in embodiment 1.

Fig. 4 is a flowchart showing details of the abnormal stop process in step S106 in fig. 3.

Fig. 5 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 1 of embodiment 1.

Fig. 6 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 2 of embodiment 1.

Fig. 7 is a configuration diagram of a brine cooling machine as a target device in embodiment 2.

Fig. 8 is a flowchart for explaining control of the abnormality detection process in embodiment 2.

Fig. 9 is a flowchart for explaining the control of the abnormal stop process of step S216 of fig. 8.

Fig. 10 is a flowchart for explaining control of abnormality detection processing in modification 1 of embodiment 2.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following description will be given of a plurality of embodiments, but it is intended at the beginning of the application that the configurations described in the embodiments can be appropriately combined. In addition, the same or corresponding portions in the drawings are denoted by the same reference numerals and the description thereof is not repeated.

Embodiment 1.

Specifically, the refrigeration cycle apparatus 100 shown in fig. 1 is an air-cooled refrigerator equipped with a 2-stage compressor. The refrigeration cycle apparatus 100 includes: a cooling source unit 101, and a load unit 102 provided inside the refrigeration warehouse 25. The refrigeration cycle apparatus 100 is provided in the refrigeration warehouse 25. The cooling source unit 101 storing the compressor 1 and the air-cooled condenser 3 is provided outdoors because of the air-cooling type.

In the following embodiments, a specific example of the refrigeration cycle apparatus will be described as a refrigerator, but the technique related to the error detection and the abnormal stop suppression of the expansion valve described in the following embodiments is also applicable to an air conditioner.

The cooling source unit 101 includes: the compressor 1, the oil separator 2, the air-cooled condenser 3, the intercooler 4, the oil cooler 7, the intermediate cooling expansion valve 8, the oil cooling expansion valve 9, and the motor cooling expansion valve 10. These expansion valves are electronic expansion valves.

The load unit 102 includes a main liquid expansion valve 5 (electronic expansion valve), an evaporator 6, an evaporation pressure sensor 27, and a temperature sensor 28.

The compressor 1, the oil separator 2, the air-cooled condenser 3, the intercooler 4, the main liquid expansion valve 5, and the evaporator 6 are connected by a main flow refrigerant pipe 20. The motor-cooling refrigerant pipe 23 branches from the main flow refrigerant pipe 20, and is connected to the compressor 1 via the motor-cooling expansion valve 10. The intercooler refrigerant pipe 21 branches from the main flow refrigerant pipe 20, and is connected to the compressor 1 via the intercooler expansion valve 8 and the intercooler 4. The oil cooler refrigerant pipe 22 branches from the main flow refrigerant pipe 20, and is connected to the compressor 1 via the oil cooling expansion valve 9 and the oil cooler 7. The oil supply pipe 24 is connected to the compressor 1 from the oil separator 2 through the oil cooler 7.

The cooling source unit 101 further includes temperature sensors 11, 15 to 19, pressure sensors 12 to 14, and a control device 110.

The temperature sensor 11 detects the temperature of the refrigerant sucked into the compressor 1. The pressure sensor 12 detects the pressure of the refrigerant sucked by the compressor 1. The pressure sensor 13 detects the pressure of the refrigerant sucked into the intermediate chamber of the compressor 1. The pressure sensor 14 detects the pressure of the refrigerant discharged from the compressor 1. The temperature sensor 15 detects the temperature of the refrigerant discharged from the compressor 1. The temperature sensor 16 detects the temperature of the liquid refrigerant flowing out from the first flow path outlet of the intercooler 4. The temperature sensor 17 detects the temperature of the gas refrigerant flowing out from the second flow path outlet of the intercooler 4. The temperature sensor 18 detects the temperature of the refrigerating machine oil flowing out from the oil cooler 7. The temperature sensor 19 detects the temperature of the gas refrigerant flowing out of the oil cooler 7. The temperature sensor 28 detects the temperature of the gas refrigerant at the outlet of the evaporator 6.

The blower of the air-cooled condenser 3, the blower of the evaporator 6, and the compressor 1 are driven by an inverter not shown. The control device 110 instructs the inverter of the operating frequency (rotational speed). The control device 110 stores the set temperature set by the user in the memory 112 via a remote controller, not shown.

The control device 110 determines the operation and stop of the refrigeration cycle apparatus 100 by comparing the in-room temperature detected by the in-room temperature sensor 26 with the set temperature stored in the memory 112.

The configuration shown above is a specific example for explaining the refrigeration cycle apparatus according to the present embodiment, but is not limited thereto.

The high-temperature and high-pressure gas refrigerant discharged from the compressor 1 is separated from the refrigerating machine oil when passing through the oil separator 2. The gas refrigerant separated from the refrigerating machine oil flows into the air-cooled condenser 3.

In the air-cooled condenser 3, the outside air exchanges heat with the refrigerant by the blower driven by the inverter. As a result, the gas refrigerant condenses into a liquid refrigerant.

The liquid refrigerant flowing out of the air-cooled condenser 3 is cooled to increase the supercooling degree when passing through the intercooler 4, and is depressurized to become a low-pressure two-phase refrigerant when passing through the main liquid expansion valve 5, and flows into the evaporator 6.

In the evaporator 6, the air in the reservoir exchanges heat with the refrigerant by the blower driven by the inverter. As a result, the two-phase refrigerant evaporates into a gas refrigerant.

The gas refrigerant flowing out of the evaporator 6 is sucked into the compressor 1, and the refrigerant in the main flow refrigerant pipe 20 circulates once.

The intercooler 4 has: a first flow path through which the refrigerant of the main flow refrigerant pipe 20 flows, and a second flow path through which the refrigerant depressurized in the intermediate cooling expansion valve 8 flows. In the intercooler 4, the two-phase refrigerant flowing through the second flow path exchanges heat with the liquid refrigerant flowing through the first flow path of the main flow. The two-phase refrigerant having passed through the second flow path of the intercooler 4 is gasified, and flows into the intermediate chamber of the compressor 1 through the intercooler refrigerant pipe 21.

In the oil cooler 7, the two-phase refrigerant depressurized in the oil cooling expansion valve 9 exchanges heat with the refrigerating machine oil flowing out of the oil separator 2. As a result, the refrigerating machine oil is cooled. In the oil cooler 7, the two-phase refrigerant is gasified. The vaporized refrigerant flows into the intermediate chamber of the compressor 1 through the oil cooler refrigerant pipe 22. On the other hand, the refrigerating machine oil cooled by the oil cooler 7 is supplied to the compressor 1 through the oil supply pipe 24.

The two-phase refrigerant decompressed by the motor cooling expansion valve 10 flows into the motor chamber of the compressor 1, and cools a motor, not shown.

The control device 110 includes CPU (Central Processing Unit) a 111, a memory 112 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input/output buffer (not shown) for inputting and outputting various signals, and the like. The CPU111 is a control unit (controller) that expands and executes a program stored in the ROM in the RAM or the like. The program stored in the ROM is a program written with the processing steps of the control device 110. The control device 110 executes control of each device in the refrigeration cycle apparatus 100 according to these programs. The control is not limited to the software-based processing, but can be performed by dedicated hardware (electronic circuit).

The control device 110 controls the frequencies of the compressor 1, the blower of the air-cooled condenser 3, and the blower of the evaporator 6. Here, "frequency" means the frequency of the inverter driving the motor, and means the rotational speed of the motor driving the compressor or the blower.

In the compressor 1, the control device 110 compares the target evaporation temperature stored in advance in the memory 112 with a saturation temperature converted value (evaporation temperature) of the evaporation pressure detected by the evaporation pressure sensor 27, and controls the frequency of the compressor 1at regular time intervals. If the evaporation temperature is higher than the target evaporation temperature, the control device 110 increases the frequency of the compressor 1 to enhance the cooling capacity.

Regarding the blower of the air-cooled condenser 3, the control device 110 calculates a target condensing temperature using a measured value of the outside air temperature or the like, based on an operation formula of the target condensing temperature stored in the memory 112. The control device 110 controls the frequency of the blower of the air-cooled condenser 3 at regular intervals based on the difference between the target condensing temperature and the condensing temperature, which is the saturation temperature corresponding to the pressure detected by the pressure sensor 14. For example, if the condensing temperature is higher than the target condensing temperature, the control device 110 increases the frequency of the blower, and if the temperature is the opposite temperature, the frequency of the blower is decreased.

Regarding the blower of the evaporator 6, the control device 110 controls the frequency of the blower of the evaporator 6 based on the in-house temperature detected by the in-house temperature sensor 26 and the set temperature set by the user. For example, the control device 110 normally operates the blower at a frequency of 60Hz, and when the temperature in the house is lowered and approaches the set temperature (temperature control stop temperature), the frequency is set to 30Hz to perform the energy-saving operation.

Regarding the expansion valve 8 for intermediate cooling, the control device 110 calculates the degree of superheat of the intermediate cooler, which is the difference between the detected value of the temperature of the outlet gas of the intermediate cooler detected by the temperature sensor 17 and the saturation temperature of the intermediate pressure detected by the pressure sensor 13. The control device 110 controls the opening degree of the expansion valve 8 for intermediate cooling at regular time intervals based on the difference between the degree of superheat and the target degree of superheat of the intercooler stored in advance in the memory 112.

Regarding the oil-cooling expansion valve 9, the control device 110 controls the opening degree of the oil-cooling expansion valve 9 at regular intervals based on the difference between the detected value of the temperature sensor 18, that is, the oil supply temperature, and the target oil supply temperature stored in the memory 112 in advance. Here, the control device 110 may control the opening degree of the oil-cooling expansion valve 9 by using the discharge temperature detected by the temperature sensor 15 instead of the oil supply temperature.

Regarding the motor-cooling expansion valve 10, the control device 110 controls the opening degree of the motor-cooling expansion valve 10 at regular intervals based on a difference between a detected value of a motor chamber temperature sensor, not shown, and a target motor chamber temperature stored in advance in the memory 112.

Regarding the main liquid expansion valve 5, the control device 110 controls the opening degree of the main liquid expansion valve 5 at regular time intervals based on the difference between the evaporator outlet gas temperature detected by the temperature sensor 28 and the saturation temperature converted value (evaporation temperature) of the evaporation pressure detected by the evaporation pressure sensor 27, that is, the superheat SHc of the refrigerant in the outlet portion of the evaporator 6.

Fig. 2 is a flowchart for explaining the periodic control of the various electronic expansion valves performed by the control device 110. The control device 110 performs periodic control of the electronic expansion valve at regular time intervals, that is, at regular intervals (about several tens of seconds).

In step S1 of fig. 2, the control device 110 determines whether or not the timer T1 for counting the control period of the periodic control has reached the control period set in advance and stored in the memory 112. When the control cycle arrives (yes in S1), the control device 110 advances the process to step S2.

In step S2, the control device 110 calculates a periodically controlled opening degree variation Δpls. In step S3, the control device 110 outputs Δpls calculated in step S2 to the pulse motor of the target electronic expansion valve.

By repeating the above, the control amount to be controlled by the electronic expansion valve can be maintained before and after the target value.

The control device of the refrigeration cycle apparatus controls the valve opening degrees of the various electronic expansion valves at regular time intervals (control cycles) so that the physical quantity (control quantity) to be controlled is shifted around the target value. As a control method, a proportional control for adjusting the valve opening in proportion to the difference between the current value and the target value of the control amount is relatively simple and convenient, and is therefore often used. In the following description, the periodic control of each electronic expansion valve is also described on the premise of proportional control, but other control methods may be used to perform the periodic control.

The control method of each actuator described above is a normal control method, and a specific example is shown for the purpose of explaining the embodiment of the present application, but the present application is not limited thereto.

Here, a study is made on the main liquid expansion valve 5. The main liquid expansion valve 5 will be briefly described with reference to fig. 2, in which a regular control is performed regularly in a normal state. The control device 110 controls the opening degree of the main liquid expansion valve 5 at each control cycle based on the degree of superheat SHc of the refrigerant at the outlet portion of the evaporator 6, which is a control amount of the periodic control, and the target degree of superheat SHcm stored in the memory 112 in advance during the operation of the compressor 1. For example, the control period is set to 30 seconds, and this value is set in advance and stored in the memory 112. The control period is timed by a timer T1 on the software of the control device 110. In step S1, control device 110 determines whether or not the count of timer T1 has reached 30 seconds. When the timer T1 reaches 30 seconds (yes in S1), the control device 110 calculates an opening degree change Δpls of the main liquid expansion valve 5 under periodic control (step S2), and outputs an opening degree to the pulse motor of the main liquid expansion valve 5 (step S3). When a pulse corresponding to Δpls is applied to the pulse motor, the opening degree of the main liquid expansion valve 5 is changed by Δpls.

The periodic control of fig. 2 is continuously performed every control cycle during the operation of the compressor 1. The failure detection of the electronic expansion valve is performed in parallel with the periodic control.

However, in the failure detection function of the electronic expansion valve, the evaporator outlet superheat may deviate from the normal range due to abrupt change in the heat load or temporary use outside the normal use range, and there is a concern that the evaporator outlet superheat may be abnormally stopped by erroneous detection. For example, when the heat load is suddenly changed, a situation in which a new load (object to be cooled) is carried into a cooling warehouse is considered. In this case, the temperature in the reservoir increases, and thus, for example, if the evaporator is used, the degree of superheat at the evaporator outlet increases. If the heat capacity of the cargo is large, the temperature may be reduced for a long time, and the cargo may be stopped abnormally by the abnormality detection process.

In addition, the normal use range is specifically an operation range defined by a manufacturer of the refrigeration cycle apparatus, and may be temporarily used in an operation state that deviates from the use range due to a user's use, a change in outside air temperature, or the like. Further, the abrupt change in load may temporarily deviate from the range of use.

If the refrigeration cycle apparatus is abnormally stopped and an abnormality notification is made, the abnormal state is transmitted to the equipment side of the end user. As a result, if the equipment is stopped, production using the equipment is stopped, or an operator is reminded to perform inspection, it is disadvantageous to the end user.

In the present embodiment, by reducing the abnormal stop caused by such erroneous detection, erroneous detection and erroneous reporting are avoided as much as possible.

Fig. 3 is a flowchart for explaining control of the abnormality detection process in embodiment 1. In fig. 3, the main liquid expansion valve 5 is the object of the abnormality detection process.

First, in step S101, the control device 110 determines whether the degree of superheat SHc is 30K (kelvin) or more or whether the degree of superheat SHc is 5K or less. Thereby, the control device 110 detects an abnormal state in which the degree of superheat SHc, which is a control amount based on the main liquid expansion valve 5, does not reach the target value. If the state is normal, the superheat SHc of the refrigerant at the outlet portion of the evaporator 6 is shifted around 10K. Therefore, if the superheat SHc is 30K or more, the main liquid expansion valve 5 may be fixed at a position closer to the closing direction than the desired opening degree, and if the superheat SHc is 5K or less, the main liquid expansion valve 5 may be fixed at a position closer to the opening direction than the desired opening degree. In the above case, abnormality of the main liquid expansion valve 5 is suspected.

However, in order to determine that the main liquid expansion valve 5 is abnormal due to a change in the temporary superheat SHc, a hesitation time (for example, 20 minutes) to be counted by the timer T2 is set. When the state where the superheat SHc is in the abnormal range of 30K or more and 5K or less continues for 20 minutes, the control device 110 determines that the main liquid expansion valve 5 is abnormal, and stops the refrigerator abnormally. The physical quantity used for determining an abnormality in the abnormality detection process is referred to as an abnormality determination quantity. Here, the abnormality determination amount is the degree of superheat SHc.

In step S101, if the degree of superheat SHc is within the abnormal range (yes in S101), the control device 110 advances the process to step S103, and starts counting by the timer T2. If it is already in the process of timing at this time, the control device 110 continues the timing.

In step S101, if the degree of superheat SHc is in the normal range (no in S101), the control device 110 advances the process to step S102, resets the timer T2, and advances the process to return. As a result, after a certain time has elapsed, the process returns to the start of fig. 3 again.

In step S104, control device 110 determines whether or not the count of timer T2 is 15 minutes. If the timer T2 counts 15 minutes (yes in S104), the control device 110 advances the process to step S107, and if the timer does not count 15 minutes (no in S104), the control device 110 advances the process to step S105.

In step S105, control device 110 determines whether or not the count of timer T2 is 20 minutes. Here, 20 minutes as the set value is a threshold value for determining that the main liquid expansion valve 5 is abnormal. If the count of the timer T2 is less than 20 minutes (no in S105), the control device 110 returns the process, and if the count of the timer T2 is 20 minutes or more (yes in S105), the control device 110 executes an abnormal stop process of the refrigeration cycle apparatus, which will be described later, in step S106.

In step S104, when the timer T2 counts 15 minutes, the control device 110 performs the valve operation confirmation process of the main liquid expansion valve 5 through the processes in step S107 and after step S107. The valve operation confirmation process is set to have a higher priority than the periodic control shown in fig. 2.

The periodic control shown in fig. 2 is always executed, and the opening degree variation Δpls is calculated for each control period (timer T1). The control device 110 compares the priorities including the opening degree variation amount based on other processes such as the valve operation confirmation process, selects the opening degree variation amount of the process with the higher priority, and outputs the command pulse to the main liquid expansion valve 5.

First, in step S107, the control device 110 fixes the frequencies of the inverter-driven compressor 1, the blower of the air-cooled condenser 3, and the blower of the evaporator 6 to the current frequency. By setting the frequency to be constant and making the state of the refrigerant constant, erroneous determination by the subsequent valve operation confirmation processing is prevented.

In step S108, control device 110 determines whether or not the current opening degree of main liquid expansion valve 5 is the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value). If the determination is yes in step S108, the control device 110 sets the variable N to n= -1.0 in step S109. On the other hand, when the determination is no in step S108, the control device 110 sets the variable N to n=2.0 in step S110. Here, the variable N is a variable used for calculation of the operation amount of the main liquid expansion valve 5 in step S111. The opening degree change amount Δpls with respect to the operation in the regular control immediately before the valve operation confirmation process of step S107 is instructed means an operation in the opposite direction when the variable N is negative, and means an operation in the same direction when the variable N is positive.

When the variable N is a negative value, if the opening degree of the main liquid expansion valve 5 is changed rapidly, the degree of superheat SHc is changed in a more abnormal range, which is not preferable. Therefore, when the variable N is a negative value, for example, the variable N is limited to a range of about-1.0.ltoreq.N.ltoreq.0.5. On the other hand, when the variable N is a positive value, the range of the variable N is, for example, about 1.5.ltoreq.n.ltoreq.2.0 in order to rapidly change the superheat SHc.

In step S111, control device 110 stores the degree of superheat SHc at the current time in memory 112. Further, the control device 110 calculates "operation amount=Δpls×n" using the variable N and the opening degree variation Δpls (positive and negative signs) of the main liquid expansion valve 5 calculated by the periodic control. After the operation amount is output to the main liquid expansion valve 5, the control device 110 resets the timer T1, and restarts the timer. This is to stop the calculation and output of the opening command based on the periodic control, and to measure the timing of confirming the transition of the normal determination amount in step S113 using the timer T1.

In step S112, control device 110 determines whether or not the count of timer T1 has reached 30 seconds. When the count of the timer T1 reaches 30 seconds, the control device 110 advances the process to step S113. The priority of the valve operation confirmation process of step S111 is set higher than that of the periodic control of fig. 2, and therefore the opening degree variation Δpls based on the periodic control is not output.

The timer T1 and the set value used for the periodic control are used here for 30 seconds, but other timers and other set values may be provided and used. In the case of using the timer T1 and the other timers, it is necessary to prohibit the output of the opening degree variation Δpls by the periodic control or to previously stop the operation itself of the periodic control.

For example, if the other timer is set to T5, the "reset timer T1& start of timer" of S111 is changed to "prohibit pulse output by the periodic control", and S112 is changed to "timer T5 is equal to or greater than 30 seconds? By the above, the same control can be achieved.

In step S113, the control device 110 confirms the change in the superheat SHc after the operation of the main liquid expansion valve 5 in step S111. The physical quantity used in the valve operation confirmation process to determine whether the expansion valve is normal is referred to as a normal determination quantity. Here, the normal judgment amount is the superheat SHc. When the operation amount is positive, that is, when the main liquid expansion valve 5 is changed in the opening direction, the control device 110 determines whether the superheat SHc is decreased. Conversely, when the operation amount is negative, that is, when the main liquid expansion valve 5 is changed in the closing direction, the control device 110 determines whether or not the superheat SHc increases. When the main liquid expansion valve 5 is normal, the refrigerant flow rate increases when the opening degree in the opening direction is changed, so the superheat SHc decreases, and the superheat SHc increases when the opening degree in the closing direction is changed, and this principle is used here.

In the above description, the control amount, the abnormality determination amount, and the normal determination amount are all the degree of superheat SHc, but the normal determination amount may be replaced with the evaporation pressure as the detection value of the evaporation pressure sensor 27 or the evaporator evaporation temperature as the saturation temperature thereof. In this case, step S113 is replaced with "the evaporation pressure (evaporation temperature) rises when the opening direction of the main liquid expansion valve 5 is changed, or the evaporation pressure (evaporation temperature) falls when the closing direction of the main liquid expansion valve 5 is changed".

If the determination in step S113 is negative, the main liquid expansion valve 5 is abnormal. In this case, the control device 110 returns the process. On the other hand, if the determination is yes in step S113, the main liquid expansion valve 5 is normal. In this case, the control device 110 advances the process to step S114, and resets the count of the timer T2.

By resetting the timer T2 in step S114, the abnormality detection process (S101, S103 to S105) of the main liquid expansion valve 5 ends. When the condition of step S101 is satisfied again (yes in S101), in step S103, control device 110 restarts the timer T2.

Fig. 4 is a flowchart showing details of the abnormal stop process in step S106 in fig. 3. The abnormal stop process is a process of stopping the supply of cold and hot air by stopping the refrigerator in an abnormal state and notifying the user or the user's equipment of the abnormality. The user equipment is, for example, a centralized monitoring device (a device for monitoring the current state of a refrigerator or an air conditioner by a computer, a touch panel monitor, or the like, and recording data such as a change in a set temperature, a pressure, or the like), or an end user production equipment (a food production line, an environmental test equipment, a chemical equipment, or the like).

First, in step S121, the control device 110 turns on an abnormality lamp (not shown) provided in the control panel. The control device 110 displays the abnormal content (name of abnormality) on a display (such as a liquid crystal panel) and outputs an abnormality signal to the user's device.

In step S122, the control device 110 stops each device of the refrigeration cycle apparatus. Specifically, the control device 110 transmits a stop command to an inverter (not shown) that drives the compressor 1, the blower of the air-cooled condenser 3, and the blower of the evaporator 6, and stops them. At the same time, the control device 110 stops (closes) the various solenoid valves and the various electronic expansion valves provided in the refrigeration cycle device.

The processing of step S121 and step S122 is performed sequentially in terms of software, but appears to be performed simultaneously in terms of human time perception.

In step S123, the control device 110 resets each timer used in the control flow of fig. 3. Next, the control device 110 starts timing of restarting the restriction time. The restart limit time is a start prohibition time from when the compressor 1 is stopped to when the compressor is restarted, and the refrigeration cycle apparatus cannot be restarted until the restart limit time elapses.

The above-described periodic control (S1 to S3) and the abnormality detection processing (S101, S103 to S105) of the main liquid expansion valve 5 and the valve operation confirmation processing (S107 to S114) are independently executed. In the operation of the compressor 1, the opening degree of the main liquid expansion valve 5 is adjusted by periodic control, and if the abnormality determination amount (here, the same as the control amount) is deviated from the target value greatly and enters the abnormality range, the abnormality detection process is executed. If the abnormality determination amount remains within the abnormality range, the abnormality detection process determines that the expansion valve is abnormal, and the refrigeration cycle apparatus performs an abnormal stop process.

However, if the start condition of the valve operation confirmation process is satisfied during the abnormality detection process operation, the operation of the valve opening degree by the valve operation confirmation process is performed, and as a result, if the normal determination amount (here, the same as the control amount) shows a reasonable change, it is determined that the expansion valve is normal by the valve operation confirmation process, the abnormality detection process is ended, and no abnormal stop is performed.

As described above, in the refrigeration cycle apparatus according to embodiment 1, the valve operation confirmation process is performed to confirm whether or not the electronic expansion valve is normal, before the abnormality detection process determines that the main liquid expansion valve 5 is abnormal and the refrigeration cycle apparatus is stopped abnormally. For example, when the temperature in the reservoir is high, the main expansion valve 5 may be normal but the superheat SHc exceeds 30K immediately after the start of cooling. In this case, even if the operation state temporarily deviates from the normal range, the refrigeration cycle apparatus may not be stopped. That is, the cooling/heating is continuously supplied, and unnecessary abnormality notification is not required for the user's equipment.

When the current opening degree of the main liquid expansion valve 5 is the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value), the variable N is set to be negative. In this case, since the opening degree of the main liquid expansion valve 5 is changed in the direction opposite to the opening degree changing direction of the regular control, foreign matter caught in the driving portion of the main liquid expansion valve 5 may be removed, and in this case, an effect of restoring the operation of the main liquid expansion valve 5 to normal may be obtained.

When the current opening degree of the main liquid expansion valve 5 is not the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value), the variable N is set to about 1.5 to 2, and therefore, the command value is output to be larger than the opening degree variation amount that is regularly controlled, and if the main liquid expansion valve 5 is normal, the superheat degree SHc can be rapidly (largely) changed, and the superheat degree SHc may be brought into the normal range.

Modification 1 of embodiment 1.

When a minute foreign matter gets stuck in the driving portion of the electronic expansion valve, there is a case where the control amount cannot be controlled in the vicinity of the target value because the actual valve opening cannot be changed. If the control amount deviates from the target value, the expansion valve opening degree is continuously changed in one direction in the periodic control so as to approach the target value. Namely, there are the following concerns: since the force in one direction is continuously applied to the driving portion and the state in which the foreign matter is caught is maintained, the abnormality detection process determines that the electronic expansion valve is abnormal and stops the electronic expansion valve abnormally.

Regarding the failure caused by the foreign matter, for example, the following 3 cases are assumed.

First, the foreign matter is caught in the contact portion between the external thread and the internal thread of the expansion valve. The rod for adjusting the opening degree of the valve is an external thread, and the external thread is meshed with an internal thread fixed in the expansion valve in the refrigerant. The external thread is fixed to the magnet, and when the magnet is rotated by the pulse, the external thread moves up and down by the screw mechanism to change the valve opening.

If the control amount is continuously deviated from the target value, the control device is intended to continuously operate the expansion valve opening in one direction. For example, in the case of the degree of superheat, if the current value is larger than the target value, the pulse is continuously output so as to increase the opening degree of the expansion valve.

Then, the male screw and the female screw are biased in one direction (the surface on the side of the screw), and the foreign matter is retained. Therefore, since the valve operation confirmation process is temporarily operated in the opposite direction, the foreign matter force (pressure applied to the surface of the thread on the opposite side from the previous one) is not applied by the amount of play (clearance) between the threads of the male screw and the female screw, and foreign matter may be washed away by the refrigerant and removed.

Second, the external screw thread and the internal screw thread are fixed by freezing moisture in the refrigerant. In this case, the ice particles may be peeled off by temporarily operating the expansion valve in the opposite direction.

And 3. The case of clogging the hole of the expansion valve with sludge or the like. It has a possibility of flowing to the downstream side by operating the valve in the opening direction.

In the modification of embodiment 1, the electronic expansion valve is temporarily driven in a direction opposite to the periodic control, so that an effort is made to return the electronic expansion valve to normal.

Fig. 5 is a flowchart for explaining control of the refrigeration cycle apparatus according to modification 1 of embodiment 1. The flowchart shown in fig. 5 is different from the flowchart of embodiment 1 shown in fig. 3 in that steps S104, S107, and S110 are eliminated, and steps S131 and S132 are added. The same reference numerals are given to the same processes as those of fig. 3, and the description is not repeated. In addition, there is no change in the aspect of the main liquid expansion valve 5 to which the abnormality detection process is applied.

In fig. 3, the valve operation confirmation process is performed at the time when the timer T2 of step S104 reaches 15 minutes. In contrast, in fig. 5, the valve operation confirmation process is executed before the timer T2 of step S105 reaches 20 minutes and when the current opening degree in step S108 reaches the maximum opening degree (upper limit value) or the minimum opening degree (lower limit value). The reason is that if the superheat SHc is in the abnormal range and the current opening degree reaches the maximum opening degree or the minimum opening degree, abnormality of the main liquid expansion valve 5 is suspected. Thus, an example of determining the start timing of the valve operation confirmation process is different from that of fig. 3.

In fig. 5, a timer T3 is set, and the control device 110 starts counting the timer T3 in step S131, and waits until a predetermined time, for example, 20 seconds, elapses in step S132. This is considered to be the time until the refrigerant state stabilizes after the frequencies of the blower and the compressor are fixed to a constant value. In fig. 3, an example of a simple embodiment is shown, but in fig. 5, step S132 is provided. Thus, for example, in the case where the valve operation confirmation process of the main expansion valve 5 is started during the frequency change in the regular control of the frequency of the compressor, the valve operation confirmation process is easily performed at the time of the transient change.

In fig. 5, unlike fig. 3, the variable N takes only a negative value (step S109). The effect of removing foreign matter stuck to the driving portion of the main liquid expansion valve 5 is exerted by changing the opening degree in the direction opposite to the direction indicated by Δpls in the regular control regardless of the current opening degree.

Modification 2 of embodiment 1.

In modification 2 of embodiment 1, it is shown that false detection prevention of abnormality similar to embodiment 1 can be applied to the oil-cooling expansion valve 9.

In the flowchart shown in fig. 6, steps S101, S102, S104, S108, S109, S111 to S113 are deleted from the flowchart of fig. 3 taken in embodiment 1, and steps S141 to S149 are added. Note that the same reference numerals are given to the same processes as those in fig. 3, and the description is not repeated.

As shown in S1 of fig. 2, the control device 110 periodically controls the oil cooling expansion valve 9 in 45-second cycles counted by the timer T1. In the periodic control of the oil-cooling expansion valve 9, the opening degree control is performed based on the difference between the oil supply temperature Toil detected by the temperature sensor 18 and the target oil supply temperature stored in the memory 112 in advance. At this time, the oil supply temperature is a control amount.

In the abnormality detection process of the oil-cooling expansion valve 9 shown in fig. 6, an example is shown in which only the fixation in the closing direction with respect to the required opening degree is detected. Specifically, when the state where the oil supply temperature is 50 ℃ or higher, for example, in step S141 is continued for 20 minutes in step S105, the control device 110 determines that the oil cooling expansion valve 9 is abnormal. The abnormality determination amount is the oil supply temperature at this time.

In step S149 of the valve operation confirmation process, the oil supply temperature Toil detected by the temperature sensor 18 is used for the normal determination and is determined.

The control amount, the abnormality determination amount, and the normal determination amount are set to the oil supply temperature Toil in this case, but may be set to the discharge temperature Td detected by the temperature sensor 15. The reason is that when the opening degree of the oil-cooling expansion valve 9 changes, the discharge temperature Td changes due to a change in the temperature of the refrigerating machine oil supplied to the compressor 1. In the case where the discharge temperature Td is used, in step S141 of the abnormality detection process, it is determined that the discharge temperature Td is abnormal when, for example, 80 ℃ or higher.

Further, in the flowchart of fig. 6, an example of performing the valve operation confirmation processing 2 times is shown. Accordingly, a counter C1 for counting the number of times of execution of the valve operation confirmation process is added and used in step S145. That is, in step S145, it is determined whether or not the counter C1 is 1 or less. If C1 is equal to or less than 1 (yes in S145), that is, if the valve operation confirmation processing is not performed or if 1 valve operation confirmation processing is performed, the valve operation confirmation processing is performed in step S107 and after step S107. If C1 > 1 (no in S145), the control device 110 returns the process since the valve operation confirmation process is completed 2 times.

On the other hand, in the case where no is determined in step S141, that is, in the case where the oil supply temperature Toil is less than 50 ℃ and enters the normal range, the count of the counter C1 is reset in step S142. If the determination is yes in step S105, the control device 110 resets the counter C1 because the refrigeration cycle apparatus is abnormally stopped by the abnormality detection process.

In step S146, it is determined whether or not the current opening degree of the oil-cooling expansion valve 9 is the maximum opening degree (upper limit value). Unlike step S108 of fig. 3, it is not determined whether or not the minimum opening degree (lower limit value) is set because only the closing fixation is considered in step S141. That is, when the oil-cooling expansion valve 9 is fixed in a state where the opening degree is small, the opening degree change amount Δpls is set to a positive amount in order to approach the target value in the periodic control, and the opening degree is to be changed in the opening direction. This is because if the state where the oil supply temperature Toil is high is continued, the command value of the opening degree of the final oil-cooling expansion valve 9 reaches the maximum opening degree (upper limit value).

In step S147, the processing is almost the same as that in step S111 of fig. 3, but since the normal determination amount is different, the stored physical amount is the oil supply temperature Toil. Further, since the valve operation confirmation process is performed, the count of the counter C1 is incremented by 1.

Since the control cycle of the periodic control of the oil-cooling expansion valve 9 is 45 seconds, the value of the timer T1 is compared with 45 seconds in step S148.

When the opening degree of the oil-cooling expansion valve 9 is changed in the opening direction, the oil supply temperature Toil decreases when the oil-cooling expansion valve 9 is normally operated. In step S149, the presence or absence of the operation of the oil-cooling expansion valve 9 is determined by using this principle.

As described above, in modification 2 of embodiment 1, the valve operation confirmation processing of steps S107 to S149 is performed 2 times, whereby a larger opening degree change can be performed with respect to the expansion valve to be subjected to the processing, and the effect of facilitating the change of the normal determination amount is obtained.

In addition, if there is a variation in the heat load before and after the timing of performing the valve operation confirmation processing, it is possible to not accurately determine whether the expansion valve is normal, but by performing the valve operation confirmation processing 2 times, erroneous determination can be suppressed.

In addition, although embodiment 1 shows a configuration in which the refrigerator shown in fig. 1 is also provided with a load side device (such as an evaporator 6), control related to suppression of stop of abnormality detection by the expansion valve shown in this embodiment can be applied to a condensing unit that does not include the main liquid expansion valve 5 and the evaporator 6. In this case, the electronic expansion valve in the condensing unit is the application object of the control.

The present invention can also be applied to a control of an electronic expansion valve configured to configure a refrigerator by a combination of a condensing unit and a load side controller. The load side controller is electrically connected to the main liquid expansion valve 5, the evaporator 6, and the in-tank temperature sensor 26, which are load side devices, and the condensing unit, and controls the condensing unit and the load side devices based on the detected value and the set temperature of the in-tank temperature sensor 26. In this case, the abnormality detection process is applied to the main liquid expansion valve 5 by the load side controller, and the abnormality detection process can be applied to the electronic expansion valve provided in the condensing unit by the control device of the condensing unit.

Embodiment 2.

Embodiment 2 shows a case where abnormality detection processing can be applied to other expansion valves of other refrigeration cycle apparatuses, similarly to the modification of embodiment 1. Specifically, although embodiment 1 describes an example of application to a refrigerator, embodiment 2 describes an example of application to a brine cooler.

Fig. 7 is a configuration diagram of a brine cooling machine as a target device in embodiment 2. The brine cooler 200 includes a constant speed compressor 31, an oil separator 2, a water-cooled condenser 32, an intercooler 4, a main liquid expansion valve 5, an intermediate cooling expansion valve 8, a motor cooling expansion valve 10, a brine cooler 34, and a water-cooled oil cooler 38.

The main flow refrigerant pipe 20, the intercooler refrigerant pipe 21, the motor cooler refrigerant pipe 23, the oil supply pipe 24, the cooling water pipe 33, and the brine pipe 35 connect the above components.

The brine cooler 200 further includes temperature sensors 11, 15 to 18, 28, 36, 37, pressure sensors 12 to 14, an evaporation pressure sensor 27, and a control device 110. The temperature sensors 36, 37 detect the temperature of the brine at the brine inlet and outlet of the brine cooler 34, respectively.

The same reference numerals are given to the same devices as those in fig. 1, and the description thereof will not be repeated. The pump for pumping the cooling water and the brine is a field device, and therefore is not shown.

The constant speed compressor 31 is not variable speed as in inverter driving, and is operated at a constant speed by a commercial power supply of 50Hz, 60Hz, or the like, for example. The constant speed compressor 31 includes a mechanical capacity control mechanism (not shown) for controlling the discharge amount. The capacity control mechanism can change the operating capacity by bypassing the compressed gas of the constant speed compressor 31 to a part of the suction side in the compressor and reducing the discharge amount.

The control device 110 controls the capacity control means based on, for example, a difference between the brine outlet temperature detected by the temperature sensor 37 and a target brine outlet temperature stored in advance in the memory 112. If the brine outlet temperature is higher than the target brine outlet temperature, the control device 110 increases the capacity of the capacity control mechanism to increase the compressor discharge amount.

The water-cooled condenser 32 is a heat exchanger that condenses the refrigerant gas by exchanging heat between the cooling water flowing through the cooling water pipe 33 and the high-temperature and high-pressure refrigerant gas discharged from the constant-speed compressor 31.

The cooling water having the temperature increased by the water-cooled condenser 32 is cooled by a cooling tower of a field-side device, not shown, and then returned to the water-cooled condenser 32. The cooling water is pumped by a cooling water pump of a field device (not shown) into a cooling water pipe 33, and circulated through a water-cooled condenser 32 and a cooling tower. The cooling water pump is operated and stopped in conjunction with the operation and stop of the brine cooler 200. At this time, the following control may be adopted: the cooling water pump is stopped after the cooling water pump is continued to operate for several tens of seconds after the constant speed compressor 31 is stopped.

The brine cooler 34 is a heat exchanger that exchanges heat between the low-pressure low-temperature two-phase refrigerant depressurized by the main liquid expansion valve 5 and brine (antifreeze) flowing through the brine pipe 35. Brine is pumped by a brine pump, not shown. In the case of using the brine cooler, the brine pump is operated without being substantially stopped even when the compressor is stopped.

The water-cooled oil cooler 38 is a heat exchanger that exchanges heat between the refrigerating machine oil flowing in from the oil separator 2 and the cooling water flowing through the cooling water pipe 33, and cools the refrigerating machine oil. The cooling water pipe 33 of the water-cooled oil cooler 38 merges with the cooling water pipe 33 of the water-cooled condenser 32, and is connected to a cooling tower (not shown).

A shell-and-tube or plate heat exchanger is used for the water-cooled condenser 32, the brine cooler 34, and the water-cooled oil cooler 38.

The control device 110 of fig. 7 has a function of outputting an operation/stop command to a cooling water pump and a brine pump, not shown, in addition to the control of the brine cooler 200. For example, the control device 110 uses a junction with a voltage to output an operation command and a stop command to the pump of the field device.

In the brine cooler 200 according to embodiment 2, the control methods of the main liquid expansion valve 5, the intermediate cooling expansion valve 8, and the motor cooling expansion valve 10 are the same as those of embodiment 1, and therefore, the description thereof will not be repeated.

Fig. 8 is a flowchart for explaining control of the abnormality detection process in embodiment 2. In fig. 8, the main liquid expansion valve 5 is also described as the object of the abnormality detection process. Here, an example will be described in which the control cycle of the periodic control of the main liquid expansion valve 5 is 30 seconds.

In the example shown here, the abnormality detection process of the main liquid expansion valve 5 is configured to: in step S204, when the degree of superheat SHc is detected to be 35K or more and 3K or less, the routine proceeds to step S216, where the abnormal stop is immediately performed.

First, in step S201, the control device 110 determines whether the degree of superheat SHc is 27K or more or whether the degree of superheat SHc is 7K or less. 27K and 7K used in step S201 are second thresholds. The second threshold value is a value that is biased to the normal side with respect to the first threshold values (35K and 3K) used in the abnormality detection processing in step S204, and is stored in the memory 112 of the control device 110 in advance.

If the determination in step S201 is yes, the process advances to step S203. In step S203, control device 110 determines whether or not counter C1 is 0 (not implemented). The counter C1 is a counter that counts the number of times the valve operation confirmation process is performed. If not (yes in S203), control device 110 advances the process to step S205. On the other hand, if the execution is completed 1 time (no in S203), control device 110 advances the process to step S204.

In step S205, the control device 110 multiplies the current opening degree of the main liquid expansion valve 5 by a ratio (for example, 15%) set in advance and stored in the memory 112 to calculate an opening degree variation δpls.

In step S206, the control device 110 compares δpls calculated in step S205 with Δpls calculated in the periodic control. If δpls is small (yes in S206), the control device 110 substitutes the value of δpls into Δpls in step S207. The sign of positive and negative at this time remains the same as Δpls.

In step S208, the control device 110 fixes the capacity of the capacity control mechanism (capacity control valve) of the constant speed compressor 31 to a value at that time.

In step S209, it is determined whether or not the current opening degree of the main liquid expansion valve 5 is the maximum opening degree or the minimum opening degree. When the determination in step S209 is yes, the control device 110 sets the variable N to n= -1.0 in step S210. On the other hand, when it is determined as no in S209, the control device 110 sets the variable N to n=1.0 in step S211.

Since Δpls calculated in steps S205 to S207 is used as it is, the variable N is set to 1.0 in steps S210 and S211, and is used as a variable for changing only the sign.

In step S212, the control device 110 stores the evaporation pressure LP (normal determination amount) detected by the evaporation pressure sensor 27 at that time in the memory 112. Then, the control device 110 calculates the operation amount "Δpls×n" in the valve operation confirmation process, and outputs a command corresponding to the calculated operation amount to the main fluid expansion valve 5. Then, control device 110 increases the count of counter C1 by 1, resets the count of timer T1, and then starts the count of timer T1.

In step S213, control device 110 determines whether or not timer T1 has reached the control cycle for 30 seconds. If it has arrived (yes in S213), control device 110 advances the process to step S214.

In step S214, the control device 110 confirms whether the evaporation pressure LP, which is the normal determination amount, has changed, based on the opening degree change instruction output in step S212. When the main liquid expansion valve 5 is changed in the opening direction, it is checked whether the evaporation pressure LP is rising or not, and when the main liquid expansion valve 5 is changed in the closing direction, it is checked whether the evaporation pressure LP is falling or not. If yes in step S214, control device 110 determines that main fluid expansion valve 5 is normal, and returns the process. At this time, even if step S201 is satisfied, the counter C1 is 1, and therefore, no is branched in step S203, and the valve operation confirmation processing in step S208 and after step S208 is not performed.

If no in step S214, the control device 110 determines that the main liquid expansion valve 5 is abnormal, resets the counter C1 in step S215, and abnormally stops the brine cooler by the abnormal stop process in step S216.

If no in step S201, that is, if the degree of superheat SHc is in the normal range, the control device 110 resets the counter C1 in step S202, and returns the process. Here, since the counter C1 is reset to 0, if the process branches to yes again in step S201, the process branches to yes also in step S203, and the valve operation confirmation process in step S208 and after step S208 is executed again.

In step S221, the control device 110 turns on an unshown abnormal lamp, and displays abnormal contents on an unshown display. The control device 110 outputs an abnormality signal to the outside such as a field device.

In step S222, the control device 110 stops each equipment of the brine cooler. Typically, the control device 110 stops the constant speed compressor 31, and further stops (closes) various solenoid valves and various electronic expansion valves.

In step S223, the control device 110 resets each timer used in the flowchart of fig. 8, and starts counting the restart limit time. The control device 110 starts the timer T4 for delay stop of the pump.

In step S224, control device 110 determines whether timer T4 has reached 60 seconds. When the operation has been completed, the control device 110 externally outputs a pump operation instruction to turn off the pump in step S225, and stops the pump.

As described above, as the abnormality detection processing of the electronic expansion valve, even when the abnormality is stopped immediately when the abnormality determination amount satisfies the threshold value (first threshold value) of the abnormality range, the valve operation confirmation processing can be performed by providing the second threshold value.

Since the second threshold is set on the normal range side of the first threshold, the valve operation confirmation process can be performed in a comparatively normal operation state before the abnormal state is reached.

In a case where the abnormality determination amount enters the abnormality range, the opening degree variation in the periodic control has a tendency to become gradually larger every time the control period elapses. In embodiment 2, the operation amount of the expansion valve outputted by the valve operation confirmation processing is configured to be smaller than the opening amount variation of the periodic control calculated by multiplying the current opening amount by a predetermined ratio. Thus, when the expansion valve is normal, the operation state is prevented from being suddenly changed due to a large change in the actual opening degree of the expansion valve, and the condition of step S204 is satisfied to perform an abnormal stop.

Modification 1 of embodiment 2.

In modification 1 of embodiment 2, it is shown that abnormality detection processing can be applied to the intermediate cooling expansion valve 8.

The periodic control of the intermediate cooling expansion valve 8 uses the superheat SHe as the control amount. The superheat SHe is the difference between the outlet gas temperature of the intercooler 4 detected by the temperature sensor 17 and the saturation temperature equivalent of the intermediate pressure detected by the pressure sensor 13.

The control device 110 controls the opening degree of the expansion valve 8 for intermediate cooling based on the difference between the target degree of superheat of the intercooler stored in advance in the memory 112 for the degree of superheat SHe by the same control as in the flowchart shown in fig. 2. The control period of the periodic control is, for example, 30 seconds.

In the compressor operation, in step S1 of fig. 2, the control device 110 determines whether or not the timer T1 is 30 seconds. When the timer T1 reaches 30 seconds, the control device 110 calculates the opening degree variation Δpls (step S2), and outputs the opening degree variation Δpls to the intermediate cooling expansion valve 8.

In the abnormality detection process, similarly, the degree of superheat SHe is used as the abnormality determination amount, and the abnormality is determined by a state in which the degree of superheat SHe is 5K or less continuing for 20 minutes.

Fig. 10 is a flowchart for explaining control of abnormality detection processing in modification 1 of embodiment 2. In fig. 10, the same reference numerals are given to the same processes as those in fig. 8, and the description is not repeated.

In step S231, the control device 110 determines whether the degree of superheat SHe is 5K or less. In step S231, if the determination is yes, the process proceeds to step S233, and if the determination is no, the process proceeds to step S232. Here, the abnormality detection process is an abnormality detection process that detects only the case where the intermediate cooling expansion valve 8 is fixed at a position closer to the opening direction than the required opening degree.

In step S233, control device 110 starts counting by timer T2. If the timer is already in step S233, the control device 110 continues the timer. The timer T2 is a timer for counting the hesitation time of the abnormality detection process.

Then, in step S234, control device 110 determines whether or not the value of timer T2 is 20 minutes or more, and if the determination result is yes, the processing proceeds to step S208, and if no, the processing proceeds to return.

Further, in step S235, the control device 110 determines whether or not the current opening degree of the intermediate cooling expansion valve 8 is equal to or greater than (minimum opening degree+|Δpls|). When the determination result is yes, the control device 110 advances the process to step S236, and when no, advances the process to step S237.

Since only the fixation on the opening direction side is detected in step S231, in step S235, the control device 110 determines whether the current opening degree is in the vicinity of the minimum opening degree. In the case of the fixed opening direction side, since the opening degree is larger than the required opening degree, the opening degree is changed in the direction in which the degree of superheat SHe decreases and Δpls calculated by the periodic control becomes negative, that is, in the direction in which the expansion valve is closed. As a result, if the state where the degree of superheat SHe is small continues, the command value for the intermediate cooling expansion valve 8 eventually reaches the minimum opening degree. If the current opening is the minimum opening, the opening cannot be further reduced, and therefore the current opening is compared with (the minimum opening+|Δpls|). If there is a margin of Δpls or more before the minimum opening, the variable N is set in step S236, and if there is no margin, the variable N is set in step S237.

The variables N are N (1) and N (2). In step S236, the control device 110 sets the variable N to N (1) = -0.5, N (2) =2.0. In step S237, the control device 110 sets the variable N to N (1) = -0.5, N (2) = -0.5. The two variables N are first set so that the opening degree is changed in a direction opposite to the opening degree change direction of the periodic control using N (1). If the foreign matter is caught in the driving portion of the intermediate cooling expansion valve 8 and cannot normally operate, the effect of removing the foreign matter is exerted by temporarily operating the driving portion of the expansion valve in the opposite direction. In the regular control, the opening degree is continuously reduced for each control cycle, and the driving portion of the expansion valve is continuously biased in the closing direction, so that the stuck foreign matter is not easily removed. Next, the second pulse output is performed using N (2).

In step S238, the control device 110 stores the current value of the degree of superheat SHe as the normal determination amount. Further, the control device 110 outputs a pulse of "Δpls×n (1)" to the intermediate cooling expansion valve 8, and then outputs a pulse of "Δpls×n (2)". In the case where step S236 has elapsed, the former is a change in the opening direction and the latter is a change in the closing direction with respect to the opening output of 2 times. When step S237 has elapsed, the open direction is changed 2 times. Subsequently, the control device 110 resets the timer T1 and starts counting again.

In step S213, control device 110 determines whether or not timer T1 has reached the control cycle for 30 seconds. In step S213, if 30 seconds have elapsed, control device 110 advances the process to step S239.

In step S239, after using the change in the opening degree of N (2) in step S238, the control device 110 confirms whether the superheat SHe shows a reasonable change. If the opening direction is changed (step S237), the degree of superheat SHe decreases, and if the closing direction is changed (step S236), the degree of superheat SHe increases, so that it can be confirmed whether the change is a reasonable change.

If no reasonable change is observed in step S239 (no), control device 110 advances the process to step S216 to execute an abnormal stop process (fig. 9) to abnormally stop the brine cooler.

If there is a reasonable change in step S239 (yes), the control device 110 advances the process to step S240, resets the timer T2, and then advances the process to return. Since the timer T2 is reset, the abnormality detection process of the intermediate cooling expansion valve 8 is stopped.

As described above, in the valve operation confirmation process, the refrigeration cycle apparatus according to embodiment 2 temporarily changes the valve opening in a direction opposite to the opening change direction of the periodic control, and then changes the opening in the same direction. By controlling the valve opening in this way, an effect of removing foreign matter caught in the driving portion of the electronic expansion valve can be expected.

(Summary)

Hereinafter, the main features of the above-described embodiments will be summarized with reference to the drawings.

The control device of the present embodiment is a control device of a refrigeration cycle device equipped with the main liquid expansion valve 5. The control device 110 shown in fig. 1 and 7 includes: a memory 112 storing a target value of a physical quantity to be controlled; and a CPU (processor) 111. The CPU111 is configured to execute the following processing including: i) An abnormality detection process of detecting an abnormality of the main liquid expansion valve 5 based on the physical quantity and the target value stored in the memory 112; ii) a valve operation confirmation process of, when an abnormality of the main liquid expansion valve 5 is detected by the abnormality detection process, transmitting a command to change the opening degree to the main liquid expansion valve 5, and determining whether or not a change corresponding to the command is observed in the physical quantity; and iii) stopping the refrigeration cycle apparatus 100 or the brine cooler 200 when no change is observed in the physical quantity in the valve operation confirmation process.

As shown in fig. 2, the control device 110 performs periodic control at regular time intervals (control periods). In the periodic control, the current value of the control amount detected by the sensor is compared with a target value stored in advance in the memory 112, and the opening degree of the electronic expansion valve is changed. Whereby the control amount is maintained around the target value.

The control device 110 performs abnormality detection processing for detecting an abnormality of the main liquid expansion valve 5 in parallel with the periodic control. In the abnormality detection process, an abnormality determination amount such as the degree of superheat SHc is detected, and an abnormality is determined by a transition thereof. Before the abnormality detection process determines that the main liquid expansion valve 5 is abnormal and stops the refrigeration cycle apparatus, in the present embodiment, a valve operation confirmation process is performed to confirm a change in a physical quantity (normal determination quantity) by changing the opening degree of the main liquid expansion valve 5, thereby determining whether the main liquid expansion valve 5 is normal or abnormal.

After the valve operation confirmation processing is performed, if the normal determination amount shows a reasonable change according to the opening degree change, the control device 110 determines that the electronic expansion valve is normal and ends the abnormality detection processing, and if not, determines that the electronic expansion valve is abnormal and continues the abnormality detection processing.

Here, the reasonable change means that when the expansion valve opening is changed in the opening direction, the refrigerant flow rate increases, so that the superheat degree, the oil supply temperature, the discharge temperature decrease, the evaporation pressure (evaporation temperature) increases, and the like. In addition, when the opening degree is changed in the closing direction, the change in the normal determination amount is opposite to the above.

In addition, the control amount, the abnormality determination amount, and the normal determination amount are often the same physical amount, and may be different.

The refrigeration cycle apparatus includes various sensors for detecting a control amount, an abnormality determination amount, and a normal determination amount.

Conventionally, when the electronic expansion valve is normal, but the operation state temporarily deviates from the normal range, there is a concern that the electronic expansion valve is abnormally stopped due to erroneous detection or excessive detection in the abnormality detection process. In the present embodiment, with such a configuration and control, if the electronic expansion valve is judged to be normal by performing the valve operation confirmation processing, the refrigeration cycle apparatus may not be unnecessarily stopped abnormally.

In addition, the refrigeration cycle apparatus is desirably operated as continuously as possible without being abnormally stopped. In the present embodiment, since the number of cases in which the system is not abnormally stopped increases, there is an effect that the supply of cold and hot is not stopped and abnormality notification to the local system is not generated.

As shown in fig. 2, the CPU111 is preferably configured to: the periodic control of the amount of change in the instruction opening degree to the main liquid expansion valve 5 or the oil cooling expansion valve 9 is performed at regular intervals based on the physical quantity and the target value. The CPU111 is configured to: in the valve operation confirmation process shown in step S110 of fig. 3 (or step S110 of fig. 6), the main liquid expansion valve 5 (or the oil-cooling expansion valve 9) is instructed to change in the same direction by a larger amount than the amount calculated by the periodic control.

In the valve operation confirmation process, the opening degree variation Δpls of the electronic expansion valve that is periodically controlled is used to output "operation amount=Δpls×variable N" in step S111 in fig. 3. Here, the opening degree variation Δpls and the variable N are both signed values. If the variable N is positive, the opening degree change in the same direction as Δpls is output, and if N is negative, the opening degree change in the opposite direction is output.

If the current opening of the electronic expansion valve is the maximum opening or the minimum opening, the opening exceeding the current opening cannot be outputted, and therefore, in step S109, the variable N is set to a negative value (for example, -1.0 n.ltoreq.0.5 or so), and if not, in step S110, the variable N is set to a positive value (for example, 1.5 n.ltoreq.2.0 or so).

By controlling in this manner, the valve operation confirmation process can be performed in consideration of the control range (the minimum opening degree or more and the maximum opening degree or less) of the electronic expansion valve.

When the variable N is positive, the opening degree can be changed to be larger than the periodically controlled variation Δpls by setting the variable N to be larger than 1. Thus, when the electronic expansion valve is normal, the control amount, the abnormality determination amount, and the normal determination amount can be changed quickly (or greatly), and the influence of the temporary deviation from the operating state can be suppressed, so that it is easy to determine whether the electronic expansion valve is normal or abnormal. Further, the abnormality detection process can be immediately ended as long as the abnormality determination amount enters the normal range.

On the other hand, if the variable N is negative, in a case where the electronic expansion valve is not normally operated because a foreign matter is caught in the driving portion of the electronic expansion valve, the valve is moved in a direction opposite to the driving direction in the regular control, and therefore, there is a possibility that the foreign matter is removed, and the operation of the electronic expansion valve can be expected to return to a normal effect. When the variable N is negative, the control amount, the abnormality determination amount, and the normal determination amount are changed in a direction to increase the abnormality when the electronic expansion valve is normally operated, and therefore, when the variable N is negative, the magnitude of the variable N is set to 1 or less.

As shown in fig. 2, the CPU111 is preferably configured to: the periodic control of the amount of change in the indicated opening degree of the main liquid expansion valve 5 is performed based on the physical quantity and the target value at regular intervals. The CPU111 is configured to: in the valve operation confirmation process shown in step S109 in fig. 3 or 5 or step S210 in fig. 8, the main liquid expansion valve 5 is instructed to change in the opposite direction to the change calculated by the periodic control.

In the valve operation confirmation process shown in fig. 3 or 5, in step S111, and in step S212 in fig. 8, the "operation amount=Δpls×variable N" is output using the periodically controlled opening degree variation Δpls of the main liquid expansion valve 5. The opening degree variation Δpls and the variable N are signed values. At this time, the variable N is always negative, and the opening degree of the valve is changed in the direction opposite to the regular control.

In this valve operation confirmation process, the valve is moved in a direction opposite to the previous driving direction in the regular control regardless of the current opening degree, and therefore foreign matter stuck in the driving portion of the electronic expansion valve may be removed, and the operation of the electronic expansion valve may be expected to return to a normal effect.

Further, even if the abnormality determination amount enters the abnormality range, the opening degree is changed in the direction opposite to the regular control, so that if the abnormality determination amount is changed to the abnormality side, it can be determined that the electronic expansion valve is operating normally, and the refrigeration cycle apparatus can be stopped abnormally without necessity.

As shown in fig. 2, the CPU111 is preferably configured to: the periodic control of the amount of change in the indicated opening degree of the main liquid expansion valve 5 is performed based on the physical quantity and the target value at regular intervals. The CPU111 is configured to: in the valve operation confirmation process of fig. 8, in step S205 to S207, the electronic expansion valve is instructed in advance based on the smaller of the amount of change calculated by the periodic control and the value indicating the current constant ratio of the opening degree of the electronic expansion valve.

That is, as shown in step S205 of fig. 8, the operation amount in the valve operation confirmation process may be obtained by multiplying the current opening of the electronic expansion valve by the ratio (%) as the set value, instead of "Δpls×the variable N". The ratio is preset and stored in the memory 112 of the control device 110. The operation amount δpls here is only a size and is not signed. Further, in step S206, the magnitudes of δpls and Δpls are compared, and the smaller opening degree variation is used as the basis for calculation of the expansion valve variation.

If the abnormality determination amount continues to enter the abnormality range, the opening degree variation Δpls of the periodic control may become excessively large. In particular, when the opening degree is changed in the direction opposite to Δpls, the abnormality determination amount is further changed to the abnormality side, so that an excessively large opening degree change is not preferable. Thus, in the valve operation confirmation processing in fig. 8, by outputting a small opening degree variation, if the expansion valve is normal, it is possible to suppress a situation in which the actual opening degree of the expansion valve is greatly varied to cause an abrupt change in the operation state, and the abnormality is stopped by the abnormality detection processing.

As shown in fig. 2, the CPU111 is preferably configured to: the periodic control of the amount of change in the indicated opening degree of the intermediate cooling expansion valve 8 is performed at regular intervals based on the physical quantity and the target value. The CPU111 is configured to: in the valve operation confirmation process of step S236 of fig. 10, after the intermediate cooling expansion valve 8 is temporarily instructed to change in the direction opposite to the change Δpls calculated by the periodic control, the intermediate cooling expansion valve 8 is instructed to change in the direction identical to the change calculated by the periodic control.

The direction of change of Δpls of the periodic control is changed to the opposite direction temporarily, and then the opening is changed to the same direction, whereby foreign matter stuck in the driving portion of the electronic expansion valve can be expected to be removed, and the operation of the electronic expansion valve returns to the normal effect.

As shown in step S104 in fig. 3 or step S143 in fig. 6, the CPU111 preferably counts the elapsed time from the detection of the abnormality in the abnormality detection process, and executes the valve operation confirmation process when the elapsed time reaches a predetermined first time (for example, 15 minutes), and as a result of the valve operation confirmation process, initializes the elapsed time when a change corresponding to the instruction is observed for the physical quantity. The CPU111 is configured to: when a predetermined second time (for example, 20 minutes) longer than the first time is reached without initializing the elapsed time, the stop process is executed. The CPU111 counts, as the elapsed time, the hesitation time from when the abnormality is detected by the timer T2 to when the stop process is performed, and executes the valve operation confirmation process until the hesitation time reaches a predetermined time.

In the case of a temporary disengagement of the operation state, since there is a possibility that the operation state is restored to the normal range after the start of the abnormality detection process, it is preferable to perform the valve operation confirmation process at the second half of the hesitation time (after 10 to 15 minutes if the hesitation time is 20 minutes) as soon as possible in the timer counting the hesitation time after the start of the abnormality detection process.

This timer is, for example, a timer T2 for counting 20 minutes when the degree of superheat is equal to or greater than 30K as abnormal in step S105 of fig. 3 or the like.

In this way, when the valve operation confirmation processing is performed during the timer operation of the hesitation time, particularly, in the latter half of the hesitation time, and the operation state is restored to the normal range in the former half of the hesitation time, the valve operation by the valve operation confirmation processing does not interfere with the expansion valve operation for each control cycle of the regular control.

Preferably, the determination time in step S104 and the determination time in step S105 in fig. 3 are set to coincide with each other. An example of this is fig. 10. In this case, the CPU111 counts the elapsed time from the detection of the abnormality in the abnormality detection process, and executes the valve operation confirmation process when the elapsed time reaches a predetermined second time (for example, 20 minutes), and initializes the elapsed time when a change corresponding to the instruction is observed in the physical quantity as a result of the valve operation confirmation process. As a result of the valve operation confirmation processing by the CPU111, the stop processing is performed when no change corresponding to the command is observed for the physical quantity. That is, the CPU111 is configured to: the elapsed time from the detection of an abnormality in the abnormality detection process to the stop process is set to be the hesitation time, and the valve operation confirmation process is executed when the hesitation time reaches a predetermined time.

Specifically, when 20 minutes are reached in which abnormality is determined when the overheat degree is not less than 30K for 20 minutes, the valve operation confirmation process is performed. In this case, the valve operation by the valve operation confirmation process is least likely to interfere with the expansion valve operation for each control cycle of the regular control.

As shown in step S105 of fig. 5, the CPU111 is preferably configured to: the valve operation confirmation process is performed by counting the hesitation time from the detection of the abnormality in the abnormality detection process to the stop process by the timer T2, until the hesitation time reaches a predetermined time and the opening degree of the main liquid expansion valve 5 reaches the upper limit opening degree or the lower limit opening degree, as shown in step S108 of fig. 5.

That is, in step S105 of fig. 5, the valve operation confirmation processing is executed at the point when the expansion valve opening degree becomes the maximum opening degree or the minimum opening degree (yes in S108) before 20 minutes (no in S105) when the abnormality is determined to be present when the overheat degree of not less than 30K continues for 20 minutes.

When the steady operation is performed within the usage range of the refrigeration cycle apparatus, it is not usual for the abnormality determination amount to continue within the abnormality range even though the maximum opening degree or the minimum opening degree is reached, and therefore it is reasonable to perform the valve operation confirmation processing at such a timing. If the maximum opening degree or the minimum opening degree is reached, there is a possibility that the temporary operating state may be released, and the valve operation confirmation processing is less necessary at this stage.

When the valve operation confirmation processing is performed at such a timing, the valve operation confirmation processing can be performed in a situation where there is a possibility of "long-time operation state disengagement" or "abnormal electronic expansion valve" other than the situation of "temporary operation state disengagement".

As shown in step S204 of fig. 8, the CPU111 is preferably configured to determine that the physical quantity (for example, the degree of superheat SHc) is abnormal by the abnormality detection process when the physical quantity is outside a first range (for example, 3K to 35K), and stop the refrigeration cycle device by the stop process. As shown in step S201 of fig. 8, the CPU111 is configured to: the abnormality detection process is performed when the physical quantity is outside a second range (for example, 7K to 27K) that is narrower than the first range. The CPU111 is configured to: the valve operation confirmation processing is executed when the physical quantity is out of the second range and enters the first range (for example, 3K to 7K or 27K to 35K).

In fig. 8, when the abnormality determination amount is detected to be within the abnormality range, that is, when the abnormality is determined, a second threshold is set at a position (normal side) wider than a first threshold for determining the abnormality range, and the operation of the valve operation confirmation processing is performed by reaching the second threshold.

For example, if the degree of superheat is equal to or less than 3K, that is, if it is determined that the abnormality is present, 3K applied in step S204 is the first threshold value. In addition, 7K slightly deviated from 3K to the normal side applied in step S201 is the second threshold value.

In this way, even when the dead time such as the timer T2 of fig. 3 is not set during the abnormality detection of the electronic expansion valve (when the first threshold is satisfied, that is, the abnormality is stopped), the valve operation confirmation process can be applied. By providing the second threshold value which is shifted to the normal side from the first threshold value, the valve operation confirmation processing can be performed in any operation state which is slightly free from the margin before the operation state in which the valve should be abnormally stopped is reached.

The refrigeration cycle apparatus 100 preferably includes a compressor 1, an air-cooled condenser 3, a first blower that blows air to the air-cooled condenser 3, an evaporator 6, and a second blower that blows air to the evaporator 6. As shown in step S107 in fig. 3 or 6 or step S131 in fig. 5, the control device 110 is configured to: the valve operation confirmation process is performed in a state where at least one of the operating capacities of the compressor 1, the first blower, and the second blower is fixed.

Similarly, the brine cooler is preferably provided with a constant speed compressor 31, a water-cooled condenser 32, and a brine cooler 34. As shown in step S208 of fig. 8 or 10, the control device 110 is configured to execute the valve operation confirmation process in a state where the operating capacity of the constant speed compressor 31 is fixed.

For example, when the compressors, the condensers, and the blowers of the evaporators are inverter driven, the operation frequencies thereof are fixed to a predetermined value, and the operation confirmation of the valve operation confirmation process is performed. In addition, in the case where the capacity (capacity) of the compressor is changed by using the mechanical capacity control mechanism, the capacity of the capacity control mechanism is also fixed, and the operation confirmation of the valve operation confirmation process is performed.

The control of the electronic expansion valve and the control of the compressor and the blower are independent functions, and often operate independently. Therefore, there is a possibility that the operating frequency of the compressor or the blower may be changed when the valve operation confirmation processing is performed, and in this case, since the operating state (refrigerant state) is changed, there is a possibility that the normal/abnormal state of the expansion valve may not be accurately determined by the valve operation confirmation processing.

By fixing the frequency in the case of inverter driving or the mechanical capacity in the case of mechanical capacity control, the operation state of the refrigeration cycle apparatus can be kept constant, and the normal or abnormal state of the expansion valve can be appropriately determined by the valve operation confirmation process.

The physical quantity to be controlled in the present embodiment is preferably at least one of the degree of superheat of the refrigerant in the refrigeration cycle device 100 or 200, the discharge temperature of the compressor 1, the oil temperature, the evaporation temperature of the refrigerant, and the evaporation pressure of the refrigerant.

In the case of the electronic expansion valve for oil cooling, the oil supply temperature or the discharge temperature can be used, although the control amount is often set to the degree of superheat in the case of the electronic expansion valve. In addition, although the main liquid expansion valve often uses a degree of superheat, the evaporation pressure (evaporation temperature), the internal temperature, or the internal temperature difference (difference between the internal temperature and the set temperature) may be used as a control amount.

With respect to various electronic expansion valves mounted in the refrigeration cycle apparatus, erroneous detection of abnormality and unnecessary stoppage of the refrigeration cycle apparatus can be prevented.

The presently disclosed embodiments are considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, and not the description of the embodiments described above, it is intended to include all modifications within the meaning and scope equivalent to the claims.

Description of the reference numerals

1 … Compressors; 2 … oil separator; 3 … air-cooled condensers; 4 … intercoolers; 5 … main liquid expansion valves; a 6 … evaporator; 7 … oil cooler; 8 … expansion valves for intermediate cooling; 9 … expansion valves for oil cooling; 10 … expansion valve for cooling motor; 11. 15-19, 28, 36, 37 … temperature sensors; 12-14 … pressure sensors; 20 … main flow refrigerant piping; 21 … refrigerant piping for an intercooler; 22 … refrigerant piping for an oil cooler; 23 … refrigerant piping for motor coolers; 24 … oil supply pipes; 25 … refrigeration warehouse; 26 … in-store temperature sensors; 27 … evaporation pressure sensor; 31 … constant speed compressor; 32 … water-cooled condensers; 33 … cooling water piping; 34 … brine chiller; 35 … brine piping; 38 … water-cooled oil cooler; 100 … refrigeration cycle devices; 101 … cooling source units; 102 … load units; 110 … control means; 112 … memory; 200 … salt cooling machine.

Claims

1. A control device for a refrigeration cycle device, equipped with an electronic expansion valve, is characterized by comprising:

A memory that stores a target value of a physical quantity to be controlled; and

A control unit configured to perform periodic control of a variation amount of the indicated opening degree of the electronic expansion valve based on the physical quantity and the target value at regular intervals,

The control unit is configured to execute:

i) An abnormality detection process that is executed in parallel with the periodic control and detects an abnormality of the electronic expansion valve based on the physical quantity and the target value stored in the memory;

ii) a valve operation confirmation process of, when an abnormality of the electronic expansion valve is detected by the abnormality detection process, transmitting a command to change an opening degree to the electronic expansion valve in preference to the periodic control, and determining whether or not a change corresponding to the command is observed in the physical quantity; and

Iii) And a stopping process of stopping the refrigeration cycle device when no change is observed in the physical quantity in the valve operation confirmation process.

2. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit is configured to: in the valve operation confirmation process, a change amount larger than the change amount calculated by the periodic control is instructed to the electronic expansion valve in the same change direction.

3. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit is configured to: in the valve operation confirmation process, the electronic expansion valve is instructed to change to an amount of change in the opposite direction to the amount of change calculated by the periodic control.

4. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit is configured to: in the valve operation confirmation process, the electronic expansion valve is instructed based on the smaller one of the variation calculated by the periodic control and a value indicating a constant ratio of the current opening degree of the electronic expansion valve.

5. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit is configured to: in the valve operation confirmation process, after the electronic expansion valve is temporarily instructed to change to a change amount in the opposite direction to the change amount calculated by the periodic control, the electronic expansion valve is instructed to change to a change amount in the same direction as the change amount calculated by the periodic control.

6. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit counts an elapsed time from the detection of the abnormality in the abnormality detection process, executes the valve operation confirmation process when the elapsed time reaches a predetermined first time, initializes the elapsed time when a change corresponding to the instruction is observed in the physical quantity as a result of the valve operation confirmation process,

The control unit is configured to: the stop processing is performed when the elapsed time has not been initialized but reached a predetermined second time longer than the first time.

7. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit counts an elapsed time from the detection of the abnormality in the abnormality detection process, executes the valve operation confirmation process when the elapsed time reaches a predetermined second time, initializes the elapsed time when a change corresponding to the instruction is observed in the physical quantity as a result of the valve operation confirmation process,

The control unit is configured to: the stopping process is performed when a change corresponding to the command is not observed in the physical quantity as a result of the valve operation confirmation process.

8. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit is configured to: the valve operation confirmation process is performed by counting the hesitation time from the detection of the abnormality in the abnormality detection process to the stop process by a timer, and executing the valve operation confirmation process until the hesitation time reaches a predetermined time and the opening degree of the electronic expansion valve reaches an upper limit opening degree or a lower limit opening degree.

9. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The control unit stops the refrigeration cycle device when the physical quantity is out of a first range,

The control section detects an abnormality in the abnormality detection process when the physical quantity is outside a second range that is narrower than the first range,

The control unit is configured to: the valve action confirmation process is executed when the physical quantity is outside the second range and enters the first range.

10. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The refrigeration cycle apparatus is provided with a compressor,

The control device executes the valve operation confirmation processing in a state where the operation capacity of the compressor is fixed.

11. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The refrigeration cycle device is provided with: a condenser, and a blower for blowing air to the condenser,

The control device executes the valve operation confirmation process in a state where the operation capacity of the blower is fixed.

12. A control device for a refrigeration cycle apparatus according to claim 1, wherein,

The refrigeration cycle device is provided with: an evaporator, and a blower for blowing air to the evaporator,

13. A control device for a refrigeration cycle device according to any one of claims 1 to 12,

The physical quantity is at least one of a degree of superheat of a refrigerant of the refrigeration cycle device, a discharge temperature of a compressor, an oil temperature, an evaporation temperature of the refrigerant, and an evaporation pressure of the refrigerant.

14. A refrigeration cycle apparatus is characterized in that,

The control device according to any one of claims 1 to 13.