CN115823787B

CN115823787B - Rapid and stable control method for room temperature between refrigeration systems

Info

Publication number: CN115823787B
Application number: CN202310113627.7A
Authority: CN
Inventors: 方忠诚; 张小猛; 康东平; 阮斌
Original assignee: Jiangsu Tuomiluo High End Equipment Co ltd
Current assignee: Jiangsu Tuomiluo High End Equipment Co ltd
Priority date: 2023-02-15
Filing date: 2023-02-15
Publication date: 2023-06-09
Anticipated expiration: 2043-02-15
Also published as: CN116576600A; CN115823787A

Abstract

The invention discloses a rapid and stable control method for the temperature of an inter-refrigeration system room. The method for controlling the temperature of the inter-refrigeration system quickly and stably comprises the following steps: acquiring the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber; obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber; determining a current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode. The method can realize the rapid and stable adjustment of the room temperature, shorten the time for the room temperature to enter a stable state, enable the equipment to rapidly reach the test state, improve the test efficiency of users, reduce the output of the heater in the temperature balancing process, and realize the energy-saving operation of the equipment.

Description

Rapid and stable control method for room temperature between refrigeration systems

Technical Field

The invention relates to the technical field of test equipment, in particular to a rapid and stable control method for the temperature of a refrigerating system room.

Background

The electronic expansion valve is a refrigerant flow regulating device driven by a stepping motor, and the device controls the internal valve rod to drive the valve needle to move by providing logic digital signals for the stepping motor, thereby realizing the control of valve flow and area. In some occasions with severe load change, high temperature control precision, wide operating condition range and the like, the traditional throttling element (such as a capillary tube, a thermal expansion valve and the like) cannot meet the requirements on temperature control precision and energy conservation, and the electronic expansion valve is increasingly widely applied.

In the control of electronic expansion valves, a great deal of regulation strategies using the superheat degree of an outlet of an evaporator as a control object are adopted, and the strategy realizes the regulation of the flow of the refrigerant by controlling the deviation between a target value and an actual value of the superheat degree, namely: when the load of the system is increased, the deviation of the superheat degree is increased, the opening degree of the electronic expansion valve is increased, and the flow rate of the refrigerant entering the evaporator is increased; when the system load is reduced, the superheat deviation is reduced, the opening degree of the electronic expansion valve is reduced, and the flow rate of the refrigerant entering the evaporator is reduced. The control strategy of the superheat degree of the outlet of the evaporator ensures that the refrigerating system runs in a state approaching the maximum refrigerating capacity at any moment, and has positive and important effects on ensuring the heat exchange of the heat exchanger of the refrigerating equipment, accelerating the cooling of the system and avoiding the operation of the air suction liquid of the compressor.

However, for a refrigeration system of an environmental test apparatus, when the intermediate temperature approaches the target temperature, especially at a small thermal load, if the refrigeration system is still operating near maximum cooling capacity, the following disadvantages may result: on one hand, the room temperature generates larger overshoot, so that the room temperature balancing process needs to be oscillated for a plurality of times, thereby prolonging the time for entering a stable state and being unfavorable for the equipment to quickly reach a test state. On the other hand, the output of the heater is larger in the temperature balancing process, which is unfavorable for the energy-saving operation of the equipment.

Disclosure of Invention

The invention provides a rapid and stable control method for the room temperature of a refrigerating system, which is used for enabling the room temperature to rapidly enter a stable state, shortening the time for enabling the room temperature to enter the stable state, enabling equipment to rapidly reach a test state and improving the test efficiency of a user.

According to an aspect of the present invention, there is provided a method for controlling rapid and stable temperature between refrigeration systems, the method comprising:

acquiring the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber;

obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber;

and determining a current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode.

Optionally, the determining the current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation of the temperature control chamber and the preset temperature deviation includes:

if the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, the current control mode of the electronic expansion valve of the temperature control chamber is a superheat deviation control mode;

And if the current temperature deviation of the temperature control chamber is greater than or equal to the preset temperature deviation, the current control mode of the electronic expansion valve of the temperature control chamber is a target opening control mode.

Optionally, the target opening control mode is:

determining a bypass mode of the refrigeration system at present, and determining a target constant temperature pre-balance opening lookup table according to the bypass mode at present and the corresponding relation between a preset bypass mode and a preset constant temperature pre-balance opening lookup table;

acquiring the current target temperature and the current external environment temperature of the temperature control chamber, and determining the current preset opening of the electronic expansion valve of the temperature control chamber according to the current target temperature of the temperature control chamber, the current external environment temperature and the target constant temperature pre-balance opening lookup table.

Optionally, the determining the target constant temperature pre-balance opening lookup table according to the bypass mode in which the bypass mode is currently located and the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table includes:

determining the mode number of the bypass mode in which the bypass mode is currently located according to the bypass mode in which the bypass mode is currently located;

and inquiring the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table according to the mode number of the current bypass mode so as to determine a target constant temperature pre-balance opening lookup table.

Optionally, the determining the current preset opening of the electronic expansion valve of the temperature control chamber according to the current target temperature of the temperature control chamber, the current external environment temperature and the target constant temperature pre-balance opening lookup table includes:

determining a target selection calculation block in the target constant-temperature pre-balance opening lookup table according to the current target temperature of the temperature control chamber and the current external environment temperature;

and determining the current preset opening of the electronic expansion valve of the temperature control compartment according to the target selection calculation block and a preset target opening value calculation algorithm.

Optionally, the target constant temperature pre-balance opening lookup table is composed of a plurality of characteristic point values of target temperature of the temperature control chamber, a plurality of characteristic point values of external environment temperature and a plurality of calculation blocks divided according to the characteristic point values;

the determining a target selection calculation block in the target constant temperature pre-balance opening lookup table according to the current target temperature of the temperature control chamber and the current external environment temperature comprises the following steps:

and determining a target selection calculation block according to the current target temperature of the temperature control chamber, the current external environment temperature and the characteristic point values.

Optionally, the preset target opening value calculating algorithm is:

wherein ,

；

；

wherein ,

selecting a minimum boundary value of a target temperature of a temperature control chamber of a calculation block for a target, +.>

Selecting a maximum boundary value of a target temperature of a temperature control chamber of a calculation block for a target, +.>

Selecting for the target a minimum boundary value of the external ambient temperature of the calculation block, < >>

Selecting for the target a maximum boundary value of the external ambient temperature of the calculation block, < ->

、

、

、

And sequentially selecting opening preset values at four vertexes of the calculation block for the target.

Optionally, the refrigeration system at least comprises a first hot gas bypass solenoid valve, a second hot gas bypass solenoid valve and a cold gas bypass solenoid valve;

the determining the bypass mode of the refrigeration system currently comprises the following steps: and determining a bypass mode of the refrigeration system according to the switch states of the first hot gas bypass electromagnetic valve, the second hot gas bypass electromagnetic valve and the cold gas bypass electromagnetic valve.

Optionally, after adjusting the opening of the electronic expansion valve according to the current control mode, the method further includes:

and judging whether the current target temperature fluctuates, and returning to execute the operation of obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber when the current target temperature fluctuates until the current target temperature does not fluctuate.

Optionally, the superheat deviation control mode is:

acquiring the current superheat degree and the target superheat degree of an evaporator; and PID adjustment is carried out on the opening of the electronic expansion valve according to the deviation of the current superheat degree and the target superheat degree of the evaporator.

According to the technical scheme, the method for controlling the temperature of the refrigerating system room quickly and stably comprises the following steps: acquiring the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber; obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber; determining a current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode. The method can be realized by the following steps: the current target temperature of the temperature control room and the actual temperature of the temperature control room are obtained in real time, the current temperature deviation of the temperature control room is obtained according to the current target temperature of the temperature control room and the actual temperature of the temperature control room, then the current control mode of the electronic expansion valve of the temperature control room can be reasonably determined based on the current temperature deviation of the temperature control room and the preset temperature deviation, finally the opening degree of the electronic expansion valve of the temperature control room is controlled according to the obtained control mode, so that the temperature of the room is quickly and stably regulated, the time for entering the stable state of the room temperature is shortened, the equipment can quickly reach the test state, the test efficiency of a user is improved, meanwhile, the output force of a heater in the temperature balance process is reduced, and the energy-saving operation of the equipment is realized.

It should be understood that the description in this section is not intended to identify key or critical features of the embodiments of the invention or to delineate the scope of the invention. Other features of the present invention will become apparent from the description that follows.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of a prior art intermediate room temperature steady state time extension;

FIG. 2 is a schematic diagram of a prior art intermediate chamber temperature balancing process with a larger heater output;

FIG. 3 is a flow chart of a method for controlling the temperature of a refrigerating system room to be quickly and stably controlled according to an embodiment of the invention;

FIG. 4 is a flow chart of another method for rapid and stable control of inter-refrigeration system room temperature provided in an embodiment of the present invention;

fig. 5 is a flowchart of a control method of a target opening control mode of an electronic expansion valve according to an embodiment of the present invention;

Fig. 6 is a schematic block diagram of a refrigeration system provided in an embodiment of the present invention;

FIG. 7 is a schematic diagram of various bypass mode profiles for a refrigeration system provided in an embodiment of the present invention;

FIG. 8 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to the bypass mode 1 according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 2 provided in an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 3 provided in an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 4 according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 5 provided in an embodiment of the present invention;

fig. 13 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 6 provided in an embodiment of the present invention;

fig. 14 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 7 provided in an embodiment of the present invention;

FIG. 15 is a schematic structural diagram of a constant temperature pre-balance opening lookup table corresponding to a bypass mode 8 according to an embodiment of the present invention;

Fig. 16 is a flowchart of a control method of another electronic expansion valve target opening degree control mode provided in the embodiment of the present invention;

fig. 17 is a block division schematic diagram of a constant temperature pre-balance opening lookup table according to an embodiment of the present invention;

fig. 18 is a schematic diagram of bilinear interpolation provided in an embodiment of the present invention.

Detailed Description

In order that those skilled in the art will better understand the present invention, a technical solution in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in which it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, shall fall within the scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and the claims of the present invention and the above figures are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the invention described herein may be implemented in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Fig. 1 is a schematic diagram of a prior art intermediate chamber temperature to steady state time extension, and fig. 2 is a schematic diagram of a heater output bias during an intermediate chamber temperature equilibration process. The inventor researches and finds that the electronic expansion valve is a refrigerant flow regulating device driven by a stepping motor, and the device controls the internal valve rod to drive the valve needle to move through screw threads by providing logic digital signals to the stepping motor, thereby realizing the control of valve flow and area. In some occasions with severe load change, high temperature control precision, wide operating condition range and the like, the traditional throttling element (such as a capillary tube, a thermal expansion valve and the like) cannot meet the requirements on temperature control precision and energy conservation, and the electronic expansion valve is increasingly widely applied.

In the control of the electronic expansion valve, a great deal of regulation strategies are adopted, which take the superheat degree of an outlet of an evaporator as a control object, and the regulation of the flow rate of the refrigerant is realized by controlling the deviation between a target value and an actual value of the superheat degree. For example, CN 103743063B discloses a control method of an electronic expansion valve in air conditioning refrigeration, which is used for controlling the opening of the electronic expansion valve in an air conditioning system, the air conditioning system comprises a compressor, an evaporator, a condenser, the electronic expansion valve and a control system, temperature sensors are respectively arranged in the middle of the evaporator, the outlet of the evaporator and the middle of the condenser, each temperature sensor is connected with the control system, and the electronic expansion valve adjusts the opening under the control of the control system, and the opening control method comprises: after the electronic expansion valve opening is initialized and is kept for t time, detecting the temperature of the middle part of the condenser

The method comprises the steps of carrying out a first treatment on the surface of the (1) When->

The electronic expansion valve is set to be at the minimum opening; (2) When->

The electronic expansion valve is set to be the maximum opening; (3) When->

Detecting the temperature of the middle part of the evaporator>

Evaporator outlet temperature->

And obtains the superheat degree of the outlet of the evaporator>

The method comprises the steps of carrying out a first treatment on the surface of the Based on the detected condenser middle temperature +.>

To set the target superheat degree of the evaporator outlet>

, wherein ,

the method comprises the steps of carrying out a first treatment on the surface of the When->

Increasing the opening of the electronic expansion valve; when (when)

Maintaining the existing opening of the electronic expansion valve; when->

Reducing the opening of the electronic expansion valve; wherein->

Saturation temperature corresponding to the minimum discharge pressure allowed for the compressor, < >>

A saturation temperature corresponding to a maximum discharge pressure allowed for the compressor;

and

All are correction parameters, and are obtained through curve fitting;

and (3) adjusting the opening of the electronic expansion valve under the refrigeration standard test working condition to obtain the basic parameters of the superheat degree of the outlet of the evaporator when the refrigeration system is in the optimal operation state.

In order to improve reliability of an adjustment strategy taking the superheat degree of an outlet of an evaporator as a control object, CN 112303972B discloses a control method and a system of an electronic expansion valve and a refrigeration system, wherein the method comprises the following steps: detecting the superheat delta of the evaporator in real time, and setting the superheat delta of the evaporator PID (proportion integration differentiation) adjustment is carried out on the opening of the electronic expansion valve by the difference value of the target superheat degree delta of the evaporator; when the superheat degree delta of the evaporator is larger than the set liquid-carrying protection superheat degree delta, setting the regulating coefficient of the PID regulation as a proportional coefficient

Integration time constant->

And differential time constant->

Otherwise, setting the adjustment coefficient of the PID adjustment as: proportional coefficient->

Integration time constant for preventing liquid from being carried>

And differential time constant->

。

The method comprises the following steps of taking the superheat degree of an outlet of an evaporator as an adjusting strategy of a control object, and adjusting the flow of the refrigerant by controlling the deviation between a target value and an actual value of the superheat degree, namely: when the load of the system is increased, the deviation of the superheat degree is increased, the opening degree of the electronic expansion valve is increased, and the flow rate of the refrigerant entering the evaporator is increased; when the system load is reduced, the superheat deviation is reduced, the opening degree of the electronic expansion valve is reduced, and the flow rate of the refrigerant entering the evaporator is reduced. The control strategy of the superheat degree of the outlet of the evaporator ensures that the refrigerating system runs in a state approaching the maximum refrigerating capacity at any moment, and has positive and important effects on ensuring the heat exchange of the heat exchanger of the refrigerating equipment, accelerating the cooling of the system and avoiding the operation of the air suction liquid of the compressor. However, for a refrigeration system of an environmental test apparatus, the chamber temperature is at the present temperature

Near target temperature +.>

At this time, especially at smaller heat loads, if the refrigeration system is still operating near maximum capacity, the following disadvantages may result: on the one hand, as shown in FIG. 1, results in a room temperature +.>

A large overshoot occurs +.>

The temperature balancing process needs to be oscillated for many times, so that the time for entering a stable state is prolonged, and the equipment is not beneficial to quickly reaching a test state. On the other hand, as shown in fig. 2, the heater output of the heater HT is caused to be large during the temperature balancing process, which is disadvantageous for energy-saving operation of the apparatus.

Therefore, the embodiment of the invention provides a rapid and stable control method for the room temperature of a refrigerating system, so that the room temperature can rapidly enter a stable state, the time for entering the stable state at the room temperature is shortened, the equipment can rapidly reach a test state, and the test efficiency of a user is improved.

Fig. 3 is a flowchart of a method for controlling the temperature of a refrigerating system according to an embodiment of the present invention. Referring to fig. 3, the method includes:

s110, acquiring the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber.

The current target temperature of the temperature control chamber can be obtained through a temperature setting or management platform of the temperature control chamber. Wherein the actual temperature of the temperature control chamber can be obtained by a temperature detection sensor or the like of the temperature control chamber.

S120, obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber.

Wherein, the current temperature deviation of the temperature control chamber is set as

Then->

The method comprises the following steps:

wherein ,

for controlling the current target temperature of the temperature compartment, < >>

Is the actual temperature of the temperature-controlled compartment.

S130, determining a current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode.

The specific value of the preset temperature deviation may be set according to the actual situation, which is not specifically limited herein.

In the technical scheme of the embodiment, the working principle of the method for rapidly and stably controlling the temperature of the inter-refrigeration system room is as follows: referring to fig. 3, first, a current target temperature of the temperature control chamber and an actual temperature of the temperature control chamber are obtained. Then, the current temperature deviation of the temperature control chamber is obtained according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber. And finally, determining the current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode. The method can be realized by the following steps: the current target temperature of the temperature control room and the actual temperature of the temperature control room are obtained in real time, the current temperature deviation of the temperature control room is obtained according to the current target temperature of the temperature control room and the actual temperature of the temperature control room, then the current control mode of the electronic expansion valve of the temperature control room can be reasonably determined based on the current temperature deviation of the temperature control room and the preset temperature deviation, finally the opening degree of the electronic expansion valve of the temperature control room is controlled according to the obtained control mode, so that the temperature of the room is quickly and stably regulated, the time for entering the stable state of the room temperature is shortened, the equipment can quickly reach the test state, the test efficiency of a user is improved, meanwhile, the output force of a heater in the temperature balance process is reduced, and the energy-saving operation of the equipment is realized.

Fig. 4 is a flowchart of another method for controlling the rapid and stable temperature of a refrigerating system according to an embodiment of the present invention. Optionally, with reference to fig. 4, on the basis of the foregoing embodiment, the method includes:

s210, acquiring the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber.

S220, obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber.

S230, judging whether the current temperature deviation of the temperature control chamber is smaller than a preset temperature deviation or not; if yes, go to step S240; otherwise, step S250 is performed.

The electronic expansion valve is characterized by comprising an opening degree control specific superheat degree deviation control mode and a target opening degree control mode. The current temperature deviation of the temperature control chamber is compared with the preset temperature deviation, so that the automatic and reasonable switching of the opening control mode of the electronic expansion valve can be realized, the opening control of the electronic expansion valve is more reasonable, and the rapid and stable control of the temperature control chamber can be realized.

Specifically, if the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, step S240 is executed, that is, the opening control mode of the electronic expansion valve of the temperature control chamber is a superheat deviation control mode, and in this control mode, the device can maintain a better cooling rate performance. If the current temperature deviation of the temperature control chamber is greater than or equal to the preset temperature deviation, step S250 is executed, namely, the opening control mode of the electronic expansion valve of the temperature control chamber is the target opening control mode, through the control of the mode, the rapid temperature control of the chamber temperature can be realized, the time for entering the stable state is shortened, the equipment can rapidly reach the test state, the test efficiency of the user is improved, and meanwhile, the heater output of the heater in the temperature balancing process is small, and the energy-saving operation of the equipment can be realized. Therefore, the current temperature deviation of the temperature control chamber is compared with the preset temperature deviation, and the opening control mode of the electronic expansion valve of the temperature control chamber is automatically and reasonably configured, so that the rapid and stable control of the chamber temperature is realized.

S240, the current control mode of the temperature control chamber electronic expansion valve is a superheat deviation control mode.

Specifically, if the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, step S240 is executed, that is, the opening control mode of the electronic expansion valve of the temperature control chamber is a superheat deviation control mode, and in this control mode, the device can maintain a better cooling rate performance.

Optionally, the superheat deviation control mode is: acquiring the current superheat degree and the target superheat degree of an evaporator; and PID adjustment is carried out on the opening of the electronic expansion valve according to the deviation of the current superheat degree and the target superheat degree of the evaporator.

S250, the current control mode of the temperature control chamber electronic expansion valve is a target opening control mode.

Specifically, if the current temperature deviation of the temperature control chamber is greater than or equal to the preset temperature deviation, step S250 is executed, that is, the opening control mode of the electronic expansion valve of the temperature control chamber is the target opening control mode, by controlling the opening control mode, the rapid temperature control of the chamber temperature can be realized, the time for entering the stable state is shortened, the equipment can rapidly reach the test state, the test efficiency of the user is improved, and meanwhile, the output of the heater in the temperature balancing process is small, and the energy-saving operation of the equipment can be realized.

S260, judging whether the current target temperature changes, and if so, returning to the operation of the step S220; otherwise, the procedure ends.

After determining the current control mode of the opening of the electronic expansion valve and regulating the opening of the electronic expansion valve according to the current control mode, the method further comprises the following steps: further judging whether the current target temperature fluctuates, if so, returning to the execution step S220, redefining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber, and redefining the opening control mode of the electronic expansion valve of the temperature control chamber by redefining the current temperature deviation of the temperature control chamber and the preset temperature deviation, so that the opening control mode of the electronic expansion valve can be automatically adjusted according to the actual target temperature fluctuation condition, thereby realizing accurate and reasonable control of the chamber temperature.

Specifically, whether the current target temperature fluctuates is judged, and when the current target temperature fluctuates, the operation of obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber is returned to be executed until the current target temperature does not fluctuate any more.

In the technical scheme of the embodiment, the working principle of the method for rapidly and stably controlling the temperature of the inter-refrigeration system room is as follows: referring to fig. 4, first, a current target temperature of the temperature control chamber and an actual temperature of the temperature control chamber are obtained. Then, the current temperature deviation of the temperature control chamber is obtained according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber. And secondly, judging whether the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation. If yes, the current control mode of the temperature control chamber electronic expansion valve is a superheat deviation control mode. Otherwise, the current control mode of the temperature control chamber electronic expansion valve is a target opening control mode. And finally, regulating and controlling the opening of the electronic expansion valve according to the current control mode. And after the opening degree of the electronic expansion valve is regulated according to the current control mode, further judging whether the current target temperature fluctuates, and returning to execute the operation of obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber when the current target temperature fluctuates until the current target temperature does not fluctuate. The method can be realized by the following steps: the current target temperature of the temperature control room and the actual temperature of the temperature control room are obtained in real time, the current temperature deviation of the temperature control room is obtained according to the current target temperature of the temperature control room and the actual temperature of the temperature control room, then the current control mode of the opening of the electronic expansion valve of the temperature control room can be accurately and reasonably determined by comparing the current temperature deviation of the temperature control room with the preset temperature deviation, finally the opening of the electronic expansion valve of the temperature control room is controlled according to the obtained control mode, so that the temperature of the room is quickly and stably regulated, the time for entering the stable state of the room is shortened, the equipment can quickly reach the test state, the test efficiency of a user is improved, and meanwhile, the output of a heater in the temperature balance process is reduced, and the energy-saving operation of the equipment is realized.

Fig. 5 is a flowchart of a control method of a target opening control mode of an electronic expansion valve according to an embodiment of the present invention. Optionally, referring to fig. 5, the method includes:

s251, determining a bypass mode of the refrigeration system, and determining a target constant temperature pre-balance opening lookup table according to the bypass mode of the refrigeration system and the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table.

The bypass modes of the refrigeration system are various, and the bypass modes are particularly related to the types and the number of bypass electromagnetic valves (including a hot gas bypass electromagnetic valve and/or a cold gas bypass electromagnetic valve) of the refrigeration system.

The corresponding relation between the preset bypass mode and the preset constant temperature preset balance opening lookup table is one-to-one, namely, each bypass mode corresponds to one constant temperature preset balance opening lookup table. Therefore, after the bypass mode of the refrigeration system is determined, the current constant temperature pre-balance opening lookup table of the refrigeration system can be determined according to the determined bypass mode and the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table.

S252, acquiring the current target temperature and the current external environment temperature of the temperature control chamber, and determining the current preset opening of the electronic expansion valve of the temperature control chamber according to the current target temperature, the current external environment temperature and the target constant temperature pre-balance opening lookup table of the temperature control chamber.

When judging that the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, determining that the refrigeration system reaches a constant-temperature stable state under the current working condition (namely the current bypass mode of the temperature control chamber and the current external environment temperature), setting the reasonable preset opening of the electronic expansion valve, and realizing the pre-adjustment and release of the refrigeration capacity, so that the temperature overshoot of the temperature control chamber can be well restrained, the oscillation times are reduced, the time for entering the constant-temperature state is shortened, and the rapid and stable control of the chamber temperature is realized.

The implementation principle of the target opening control mode of the electronic expansion valve provided in this embodiment is as follows: firstly, determining a bypass mode of a refrigeration system, and determining a target constant temperature pre-balance opening lookup table according to the bypass mode of the refrigeration system and the corresponding relation between a preset bypass mode and a preset constant temperature pre-balance opening lookup table. And then, acquiring the current target temperature and the current external environment temperature of the temperature control chamber, and determining the current preset opening of the electronic expansion valve of the temperature control chamber according to the current target temperature, the current external environment temperature and the target constant temperature pre-balance opening lookup table of the temperature control chamber. Therefore, when the current temperature deviation of the temperature control chamber is judged to be smaller than the preset temperature deviation, the target constant temperature pre-balance opening lookup table can be determined through the corresponding relation between the current bypass mode of the refrigerating system and the preset bypass mode and the preset constant temperature pre-balance opening lookup table, and then the current preset opening of the electronic expansion valve of the temperature control chamber can be obtained to obtain the reasonable opening preset value of the electronic expansion valve, so that the pre-adjustment and release of the refrigerating capacity are realized, the temperature overshoot of the temperature control chamber is well restrained, the time for entering a constant temperature state is shortened, the rapid and stable control of the temperature of the chamber is realized, the test state can be rapidly reached, and the test efficiency of a user is improved. And when judging that the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, determining a target constant temperature pre-balance opening lookup table according to the bypass mode and the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table by judging the bypass mode of the refrigeration system, and further determining the reasonable opening preset value of the electronic expansion valve of the temperature control chamber.

Fig. 6 is a schematic block diagram of a refrigeration system according to an embodiment of the present invention. Optionally, the refrigeration system comprises at least a first hot gas bypass solenoid valve, a second hot gas bypass solenoid valve, and a cold gas bypass solenoid valve; determining a bypass mode in which the refrigeration system is currently located, comprising: and determining a bypass mode of the refrigeration system according to the on-off states of the first hot gas bypass electromagnetic valve, the second hot gas bypass electromagnetic valve and the cold gas bypass electromagnetic valve.

The environment test equipment consists of a box body, a control system and a refrigerating system, wherein the box body mainly consists of heat insulation materials, and the temperature of a compartment can be adjusted at will within a specified range. The control system consists of a touch screen, a PLC controller, a temperature sensor, a pressure sensor and related expansion modules. Referring to fig. 6, the refrigeration system is mainly composed of a compressor COMP, a condenser COND, an evaporator EVAP, an electronic expansion valve EEV, a heater HT, a condensing FAN1, a circulating FAN2, a solenoid valve, a capillary tube, and the like. The principle of the refrigeration system is shown in fig. 6, and the cooling process is as follows: the high-temperature high-pressure gaseous refrigerant at the outlet of the compressor COMP enters the condenser COND to be condensed and then becomes liquid refrigerant, the liquid refrigerant is throttled and reduced to the inlet of the evaporator EVAP by the electronic expansion valve EEV, and the liquid refrigerant is gasified and absorbs heat and refrigerates in the evaporator EVAP. The system is provided with a heater HT, and when the temperature of the compartment approaches to the target temperature, PID control of the heater HT is started to perform thermal load hedging adjustment so as to realize accurate temperature control in the compartment. In the refrigeration state, the EEV of the electronic expansion valve can dynamically adjust the opening according to the superheat degree of the outlet of the EVAP of the evaporator. When the external load is small, the superheat at the outlet of the evaporator EVAP is reduced, and the operation condition of low refrigeration output and even zero refrigeration output of the refrigeration system can occur, so that the energy of the refrigeration system is unloaded by using a hot gas bypass loop to maintain the minimum suction pressure of the system. In addition, to maintain a reasonable suction temperature of the compressor, and avoid overheating of the compressor suction, the refrigeration system may also be configured with a cold air bypass circuit. By way of example, fig. 6 shows a hot gas bypass circuit consisting of a first hot gas bypass solenoid valve SV1, a second hot gas bypass solenoid valve SV2, a first hot gas bypass capillary tube CAP1 and a second hot gas bypass capillary tube CAP2, and a cold gas bypass circuit consisting of a cold gas bypass solenoid valve SV3 and a cold gas bypass capillary tube CAP 3. Further, referring to fig. 6, the refrigeration system further includes an ambient temperature sensor ST1, an evaporator outlet temperature sensor ST2, a compartment temperature sensor ST3, and an evaporator outlet pressure sensor SP.

Fig. 7 is a schematic diagram of various bypass mode distributions of a refrigeration system provided in an embodiment of the present invention. By way of example, taking the case that the refrigeration system is provided with the first hot gas bypass solenoid valve SV1, the second hot gas bypass solenoid valve SV2 and the cold gas bypass solenoid valve SV3, eight modes in total can be obtained according to the on-off states of the first hot gas bypass solenoid valve SV1, the second hot gas bypass solenoid valve SV2 and the cold gas bypass solenoid valve SV3, and the specific cases of the various bypass modes are shown in fig. 7. Where "1" represents solenoid valve ON and "0" represents solenoid valve OFF. For example, in the fourth bypass mode

Then, the first hot gas bypass solenoid valve SV1 is opened, the second hot gas bypass solenoid valve SV2 is opened, and the cold gas bypass solenoid valve SV3 is closed.

It should be noted that the various bypass mode conditions included in the refrigeration system are related to the specific hot bypass circuit and/or cold bypass circuit configuration of the refrigeration system, and the eight conditions listed herein are merely exemplary and may be specifically set according to the actual situation, and are not specifically limited herein.

Wherein the corresponding relation between the preset bypass mode and the preset constant temperature preset balance opening lookup table is one-to-one, namely, for each bypass mode

Is provided with a corresponding electronic expansion valve constant temperature pre-balance opening degree lookup table when the bypass mode is +.>

When the electronic expansion valve changes, the current pre-balance opening lookup table of the electronic expansion valve can be calculated only by selecting the corresponding constant-temperature pre-balance opening lookup table according to the corresponding relation between the pre-set bypass mode and the pre-set constant-temperature pre-balance opening lookup tableSetting opening value->

. Specific:

when (I)>

；

When (I)>

；

When (I)>

；

When (I)>

；

When (I)>

；

When (I)>

；

When (I)>

；

When (I)>

。

Fig. 8 to 15 are schematic structural diagrams of constant temperature pre-balance opening lookup tables corresponding to the bypass modes 1 to 8, respectively. Wherein the bypass mode 1, i.e.,

when (I)>

According to the constant temperature pre-balance opening degree lookup table shown in fig. 8; bypass mode 2, i.e.)>

When (I)>

According to the constant temperature pre-balance opening degree lookup table shown in fig. 9; bypass mode 3, i.e.)>

In the time-course of which the first and second contact surfaces,

according to the constant temperature pre-balance opening degree lookup table shown in fig. 10; the bypass mode 4, i.e.,

when (I)>

According to the constant temperature pre-balance opening degree lookup table shown in fig. 11; bypass mode 5, i.e.)>

When (I)>

According to the constant temperature pre-balance opening degree lookup table shown in fig. 12; bypass mode 6, i.e.)>

When (I)>

According to the constant temperature pre-balance opening degree lookup table shown in fig. 13; bypass mode 7, i.e.) >

In the time-course of which the first and second contact surfaces,

according to the constant temperature pre-balance opening degree lookup table shown in fig. 14; the bypass mode 8, i.e.,

when (I)>

Calculated from the constant temperature pre-equilibrium opening degree lookup table shown in fig. 15.

Fig. 16 is a flowchart of another control method of the target opening control mode of the electronic expansion valve provided in the embodiment of the present invention. Optionally, referring to fig. 16, the method includes:

s2501, determining the mode number of the bypass mode in which the bypass mode is currently located according to the bypass mode in which the bypass mode is currently located.

Among them, the refrigeration system generally has a plurality of bypass modes, and the specific number of modes is related to the on-off state of the solenoid valve in actual use. The mode numbers of the bypass modes are numbered according to the number of all bypass modes of the refrigerating system, and a constant-temperature pre-balance opening lookup table is correspondingly arranged in the bypass mode corresponding to each mode number.

S2502, according to the mode number of the bypass mode where the current bypass mode is located, inquiring the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table to determine a target constant temperature pre-balance opening lookup table.

The bypass mode corresponding to each mode number is correspondingly provided with a constant temperature pre-balance opening lookup table, so that after the refrigeration system is determined to enter a quasi-constant temperature state, the corresponding mode number of the refrigeration system can be determined according to the current bypass mode of the refrigeration system, and then the current constant temperature pre-balance opening lookup table, namely the target constant temperature pre-balance opening lookup table, can be determined by inquiring the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table according to the mode number of the bypass mode.

S2503, determining a target selection calculation block in a target constant temperature pre-balance opening lookup table according to the current target temperature and the current external environment temperature of the temperature control chamber.

The real-time target temperature and the real-time external environment temperature of the temperature control chamber of the refrigeration system under the working conditions of different bypass modes may be different, so that the target selection calculation blocks corresponding to the temperature control chamber are not necessarily the same. Therefore, after the bypass mode of the refrigeration system and the corresponding target constant temperature pre-balance opening lookup table are determined, the currently corresponding target selection calculation block is also required to be determined according to the current target temperature of the temperature control compartment of the refrigeration system and the current external environment temperature.

Fig. 17 is a block division schematic diagram of a constant temperature pre-balance opening lookup table according to an embodiment of the present invention. Optionally, the target constant temperature pre-balance opening lookup table is composed of a plurality of characteristic point values of the target temperature of the temperature control chamber, a plurality of characteristic point values of the external environment temperature, and a plurality of calculation blocks divided according to the characteristic point values. Determining a target selection calculation block in a target constant temperature pre-balance opening lookup table according to the current target temperature and the current external environment temperature of the temperature control chamber, wherein the target selection calculation block comprises: and determining a target selection calculation block according to the current target temperature of the temperature control chamber, the current external environment temperature and the values of all the characteristic points.

The constant temperature pre-balance opening lookup table is divided into calculation blocks according to the target temperature of the compartment and the external environment temperature, and the calculation blocks have no overlapping area.

Exemplary, referring to FIG. 17, the plurality of characteristic point values of the temperature-controlled compartment target temperature include

、

、

、

、

The method comprises the steps of carrying out a first treatment on the surface of the The plurality of characteristic point values of the external environment temperature comprise

、

、

、

. The calculated blocks divided according to the respective feature point values include a block OV 1-block OV4, a block OV 9-block OV12, and a block 1-block 12.

Wherein, in each constant temperature pre-balance opening degree lookup table:

；

；

；/>

；

；

；

；

；

。

the determining the target selection calculation block according to the current target temperature, the current external environment temperature and the characteristic point values of the temperature control chamber is as follows: and selecting a calculation block as a target according to a calculation block corresponding to the current target temperature of the temperature control chamber and/or the current external environment temperature meeting the condition of a certain characteristic point value range. For example, when the current target temperature of the temperature-controlled compartment and the current external ambient temperature satisfy:

when the target selecting calculation block is the calculation block OV1; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target selects the calculation block as the calculation block OV2; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

When the target selects the calculation block as the calculation block OV3; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target is selected, the calculation blockFor calculation block OV4; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target selecting calculation block is the calculation block 1;

when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

the target selecting calculation block is a calculation block 2;

when the target is selected, the calculation block is a calculation block 3;

when the target is selected, the calculation block is a calculation block 4;

when the target is selected, the calculation block is a calculation block 5;

when the calculation block is selected as the calculation block 6; />

when the target is selected, the calculation block is a calculation block 7;

when the target is selected, the calculation block is a calculation block 8;

when the target is selected, the calculation block is a calculation block 9;

when the calculation block is selected as the calculation block 10; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the calculation block is selected as the calculation block 11; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the calculation block is selected as the calculation block 12; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target selects the calculation block as the calculation block OV9; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target selects the calculation block as the calculation block OV10; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

when the target selecting calculation block is the calculation block OV11; when the current target temperature and the current external environment temperature of the temperature control chamber meet the following conditions:

When the calculation block is selected as the calculation block OV12.

The specific number and value of the characteristic point values included in the target temperature of the temperature control chamber and the characteristic point values included in the external environment temperature in the constant temperature pre-balance opening degree lookup table may be set according to actual situations, and are not particularly limited herein. Similarly, the specific division number of each block in the constant temperature pre-balance opening degree lookup table is also set according to the actual situation, and is not specifically limited herein.

S2504, determining the current preset opening of the electronic expansion valve of the temperature control compartment according to a preset target opening value calculation algorithm by the target selection calculation block.

After the target selection calculation block is determined, the current preset opening corresponding to the electronic expansion valve of the temperature control chamber is calculated according to a preset target opening value calculation algorithm.

Optionally, the preset target opening value calculation algorithm is:

wherein ,

；

；

wherein ,

Selecting for the target a minimum boundary value of the external ambient temperature of the calculation block, < > >

、

、

、

Fig. 18 is a schematic diagram of bilinear interpolation provided in an embodiment of the present invention. The preset target opening value calculation algorithm is a bilinear interpolation algorithm, and a schematic diagram thereof is shown in fig. 18.

For example, assuming that the target selected computing block is computing block 1, then

Representing the +.about.1 of the calculation block for target selection>

Minimum boundary value>

Representing the +.about.1 of the calculation block for target selection>

The maximum value of the boundary value is set,

representing the +.about.1 of the calculation block for target selection>

Minimum boundary value>

Representing the +.about.1 of the calculation block for target selection>

Maximum boundary value, opening preset value at four vertexes of target selection calculation block 1 is

、

、

、

。

Then:

，

wherein ,

if the calculation block 2, the calculation blocks 3 and …, and the calculation block 12 are selected, then

The calculation principle and steps are exactly the same as those of calculation block 1, and so on.

The implementation principle of the target opening control mode of the electronic expansion valve provided in this embodiment is as follows: first, a mode number of the bypass mode in which the current is located is determined according to the bypass mode in which the current is located. And then, according to the mode number of the current bypass mode, inquiring the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table to determine a target constant temperature pre-balance opening lookup table. And secondly, determining a target selection calculation block in a target constant-temperature pre-balance opening lookup table according to the current target temperature of the temperature control chamber and the current external environment temperature. And finally, determining the current preset opening of the electronic expansion valve of the temperature control compartment according to a preset target opening value calculation algorithm by the target selection calculation block. Therefore, when the current temperature deviation of the temperature control chamber is judged to be smaller than the preset temperature deviation, the target constant temperature pre-balance opening lookup table can be determined through the corresponding relation between the bypass mode, the bypass mode number and the preset bypass mode of the refrigerating system and the preset constant temperature pre-balance opening lookup table, and then the current preset opening of the electronic expansion valve of the temperature control chamber can be obtained to obtain the reasonable opening preset value of the electronic expansion valve, so that the pre-adjustment and release of the refrigerating capacity are realized, the temperature overshoot of the temperature control chamber is well restrained, the time for entering a constant temperature state is shortened, the rapid stable control of the temperature of the chamber is realized, the test state can be rapidly reached, and the test efficiency of a user is improved. When the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, the bypass mode of the refrigeration system is judged, the target constant temperature pre-balance opening lookup table is determined according to the mode number of the bypass mode and the corresponding relation between the preset bypass mode and the preset constant temperature pre-balance opening lookup table, a target selection calculation block is further determined in the target constant temperature pre-balance opening lookup table according to the current target temperature of the temperature control chamber and the current external environment temperature, a reasonable opening preset value of the electronic expansion valve of the temperature control chamber is determined according to the target selection calculation block and the preset target opening value calculation algorithm, and as different bypass modes correspond to different constant temperature pre-balance opening lookup tables, the corresponding constant temperature pre-balance lookup table can be determined according to the bypass mode working condition of the refrigeration system, and further the corresponding reasonable preset opening of the electronic expansion valve is further determined according to the constant temperature pre-balance lookup table, so that the refrigeration system can adapt to various working conditions, the application range is enlarged, and the applicability is improved.

It should be appreciated that various forms of the flows shown above may be used to reorder, add, or delete steps. For example, the steps described in the present invention may be performed in parallel, sequentially, or in a different order, so long as the desired results of the technical solution of the present invention are achieved, and the present invention is not limited herein.

The above embodiments do not limit the scope of the present invention. It will be apparent to those skilled in the art that various modifications, combinations, sub-combinations and alternatives are possible, depending on design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. A method for rapid and stable control of the temperature of a refrigeration system compartment, comprising:

obtaining the current temperature deviation of the temperature control chamber according to the current target temperature of the temperature control chamber and the actual temperature of the temperature control chamber; the current temperature deviation of the temperature control chamber is obtained by subtracting the actual temperature of the temperature control chamber from the current target temperature of the temperature control chamber;

Determining a current control mode of an electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber, and regulating and controlling the opening of the electronic expansion valve according to the current control mode; the determining the current control mode of the electronic expansion valve of the temperature control chamber according to the current temperature deviation and the preset temperature deviation of the temperature control chamber comprises the following steps: if the current temperature deviation of the temperature control chamber is smaller than the preset temperature deviation, the current control mode of the electronic expansion valve of the temperature control chamber is a superheat deviation control mode; if the current temperature deviation of the temperature control chamber is larger than or equal to the preset temperature deviation, the current control mode of the electronic expansion valve of the temperature control chamber is a target opening control mode; the target opening control mode is as follows: determining a bypass mode of the refrigeration system at present, and determining a target constant temperature pre-balance opening lookup table according to the bypass mode at present and the corresponding relation between a preset bypass mode and a preset constant temperature pre-balance opening lookup table; acquiring the current target temperature and the current external environment temperature of a temperature control chamber, and determining the current preset opening of an electronic expansion valve of the temperature control chamber according to the current target temperature, the current external environment temperature and the target constant temperature pre-balance opening lookup table of the temperature control chamber; the determining the current preset opening of the electronic expansion valve of the temperature control chamber according to the current target temperature of the temperature control chamber, the current external environment temperature and the target constant temperature pre-balance opening lookup table comprises the following steps: determining a target selection calculation block in the target constant-temperature pre-balance opening lookup table according to the current target temperature of the temperature control chamber and the current external environment temperature; determining the current preset opening of the electronic expansion valve of the temperature control compartment according to a preset target opening value calculation algorithm by the target selection calculation block; the preset target opening value calculation algorithm is as follows:

wherein ,

wherein ,

、

、

2. The method as set forth in claim 1, wherein the determining the target thermostatic pre-balance opening lookup table according to the bypass mode currently in and the correspondence between the preset bypass mode and the preset thermostatic pre-balance opening lookup table includes:

3. The method according to claim 1, wherein the target constant temperature pre-balance opening lookup table is composed of a plurality of characteristic point values of a target temperature of the temperature control compartment, a plurality of characteristic point values of an external environment temperature, and a plurality of calculation blocks divided according to the characteristic point values;

4. The method of claim 1, wherein the refrigeration system comprises at least a first hot gas bypass solenoid valve, a second hot gas bypass solenoid valve, and a cold gas bypass solenoid valve;

5. The method of claim 1, further comprising, after adjusting the opening of the electronic expansion valve according to the current control mode:

6. The method of claim 1, wherein the superheat deviation control mode is: