CN101233374A - freezer - Google Patents

Abstract

When in the 1<st> operation the temperature inside is maintained at target temperature by an evaporator, the cooling power of the evaporator is increased so as to carry out the 2<nd> operation for temperature inside lowering. When in the 2<nd> operation the temperature inside reaches lower limit temperature (Tmin), the compressor stops so as to carry out the 3<rd> operation. When in the 3<rd> operation the temperature inside reaches upper limit temperature (Tmax), the compressor restarts so as to carry out the 1<st> operation.

Description

freezer

technical field

[0001] The present invention relates to a refrigeration unit with a cooling heat exchanger for cooling the interior, and more particularly to an energy-saving operation method for the refrigeration unit.

Background technique

[0002] Hitherto, freezers for cooling the interiors of refrigerators, freezers, etc. have been known.

[0003] For example, Patent Document 1 discloses a refrigeration device for cooling the inside of a container used for marine transportation or the like. The refrigeration unit comprises a refrigerant circuit connected to a compressor, a condenser, an expansion valve and a cooling heat exchanger (evaporator). In the refrigerant circuit of this refrigerating apparatus, a refrigerant is circulated to perform a vapor compression refrigeration cycle. As a result, the refrigerant flowing through the cooling heat exchanger absorbs heat from the interior air and evaporates to cool the interior air. In this refrigerating device, it is possible to perform a freezing operation in which the contents in the container are refrigerated by keeping the air in the storehouse below zero degrees Celsius, and a refrigerating operation in which the contents in the container are refrigerated by making the air in the storehouse higher than 0 degrees Celsius.

[Patent Document 1] Japanese Patent Laid-Open No. 2002-327964

(The problem to be solved by the invention)

[0004] However, for example, in the above-mentioned refrigerating apparatus, it may be required to achieve a high temperature accuracy of, for example, about ±0.5° C. depending on the contents of the container or the like. Therefore, in the conventional refrigerating apparatus, the compressor is always operated while giving priority to ensuring the temperature accuracy. However, once the air inside the container cools down, the cooling load of the cooling heat exchanger does not change significantly, and it is difficult to imagine a sudden change in the outdoor air temperature that affects the cooling load. Therefore, even in a state where the cooling capacity of the cooling heat exchanger is suppressed, the temperature can be kept constant in many cases. However, in the conventional refrigerating apparatus, the compressor is always operated even in the above state, and excessive energy is consumed for driving the compressor.

Contents of the invention

The present invention is the invention in view of the above-mentioned problem, and its purpose is: in the freezer that utilizes cooling heat exchanger to cool the inside of the storehouse, the temperature in the storehouse can be kept within the target range, and energy saving can be performed. run.

(method to solve the problem)

[0006] The first invention is based on the following refrigerating device as a premise, that is, the refrigerating device includes a refrigerant circuit 10 connected to a cooling heat exchanger 14 and a compressor 11 for cooling the interior of the storehouse. A refrigerant is circulated in the refrigerant circuit 10 to perform a refrigeration cycle. In addition, the refrigerating device is characterized in that the refrigerating device includes a capacity adjustment unit 35 that adjusts the cooling capacity of the cooling heat exchanger 14 so that the temperature in the refrigerator reaches the target temperature, and the refrigerating device can Realize energy-saving operation in which the first operation, the second operation, and the third operation are performed. During the operation, when the temperature inside the refrigerator maintains the target temperature in the first operation, the cooling capacity of the above-mentioned cooling heat exchanger 14 is increased by using the capacity adjustment member 35, and the temperature inside the refrigerator is lowered to a target range including the above-mentioned target temperature. After the lower limit of the target range, the compressor 11 is stopped. In the third action, the compressor 11 is started when the interior temperature of the compressor 11 stops due to the second action and reaches the upper limit of the above-mentioned target range, and the third action is restarted. a move.

[0007] In the refrigerating apparatus of the first invention, the refrigerant circulates in the refrigerant circuit 10 to perform a vapor compression refrigeration cycle. As a result, the refrigerant flowing through the cooling heat exchanger 14 absorbs heat from the air in the refrigerator and evaporates, thereby cooling the interior of the refrigerator.

[0008] Here, in the refrigerating apparatus of the present invention, an energy-saving operation in which the compressor 11 is intermittently operated is performed. Specifically, in this energy-saving operation, operations from the first operation to the third operation described below are repeated. In addition, the target temperature of the interior temperature, and the upper limit value and the lower limit value of the target range (allowable temperature range) including this target temperature are set in this freezer.

[0009] First, in the first action, the compressor 11 is operated and the cooling capacity of the cooling heat exchanger 14 is adjusted by the capacity adjustment member 35. As a result, the temperature in the chamber gradually approaches the target temperature. When the temperature in the chamber is maintained at the target temperature due to the first operation, the second operation is performed.

[0010] In the second action described above, the compressor 11 is operated and the cooling capacity of the cooling heat exchanger 14 is increased by the capacity adjusting member 35. As a result, the temperature in the chamber gradually decreases. Then, when the interior temperature reaches the above-mentioned lower limit value during the second operation, the compressor 11 is stopped and the third operation is performed.

[0011] In the third operation described above, the compressor 11 remains in a stopped state. As a result, the refrigeration cycle is not performed in the refrigerant circuit 10, and cooling of the interior of the refrigerator by the cooling heat exchanger 14 is substantially stopped. As a result, the temperature in the chamber gradually rises to exceed the target temperature. Thereafter, when the interior temperature further rises and reaches the upper limit value, the compressor 11 is restarted to restart the first operation. When the first operation is restarted, the temperature in the chamber gradually approaches the target temperature again.

The second invention is an invention on the basis of the first invention, and is characterized in that: the above-mentioned capacity adjustment component is made of a flow adjustment valve 35, and the flow adjustment valve 35 is connected to the refrigerant circuit 10 and is connected to the compressor 11 The flow rate of the sucked refrigerant is adjusted, and in the second operation, the opening degree of the flow rate adjustment valve 35 is increased compared to the first operation to improve the cooling capacity of the cooling heat exchanger 14 .

[0013] In the second invention, the flow regulating valve 35 is connected to the refrigerant circuit 10. The flow rate regulating valve 35 constitutes capacity regulating means for regulating the cooling capacity of the cooling heat exchanger 14 by regulating the flow rate of the refrigerant sucked into the compressor 11 .

[0014] Specifically, since the opening of the flow rate adjustment valve 35 is adjusted during the first operation, the refrigerant circulation amount in the refrigerant circuit 10 is adjusted. Here, when the opening degree of the flow rate adjustment valve 35 is decreased to adjust the circulation amount of the refrigerant, the refrigerant is substantially in a wet vapor state in approximately the entire region of the cooling heat exchanger 14 which is an evaporator. Therefore, when it is assumed that the cooling capacity of the evaporator is adjusted by adjusting the opening of the expansion valve on the inflow side of the evaporator, the refrigerant flowing through the evaporator is roughly in a dry vapor state, and between the inflow end and the outflow end of the evaporator On the other hand, when the cooling capacity of the cooling heat exchanger 14 is adjusted while reducing the opening degree of the flow regulating valve 35 as shown in the present invention, the inflow end of the cooling heat exchanger 14 The temperature distribution of the refrigerant to the outflow end becomes uniform. As a result, the interior air is cooled to a relatively uniform temperature by the cooling heat exchanger 14 .

[0015] When the temperature in the storehouse is maintained at the target temperature by adjusting the opening of the flow regulating valve 35 in the first action, the second action is performed. In this second operation, since the opening degree of the flow rate adjustment valve 35 is increased, the circulation amount of the refrigerant in the refrigerant circuit 10 is also increased, and the cooling capacity of the cooling heat exchanger 14 is also increased. And, when the temperature in the refrigerator reaches the lower limit value during the second operation, the third operation similar to the above-mentioned first invention is performed.

[0016] The third invention is based on the second invention, and is characterized in that: in the third action, the opening of the flow regulating valve 35 maintains the opening at the end of the second action.

In the third invention, when the opening degree of the flow regulating valve 35 increases due to the second action, and when the temperature in the storehouse reaches the lower limit value, the opening degree of the flow regulating valve 35 maintains the original opening degree and The compressor 11 is in a stopped state and shifts to the third action. In the third operation, until the temperature in the storage reaches the upper limit and the compressor 11 is restarted, the opening degree of the flow regulating valve 35 remains the original opening degree. Accordingly, the opening degree of the flow rate adjustment valve 35 at the start of the first operation is the same as the opening degree at the end of the previous second operation for cooling the interior air by increasing the cooling capacity of the cooling heat exchanger 14 . As a result, a sufficient amount of refrigerant circulation is ensured from the time when the temperature in the refrigerator reaches the upper limit and the first operation of restarting the compressor 11 starts. As a result, the air in the warehouse is rapidly cooled, and the temperature in the warehouse quickly approaches the target temperature.

The fourth invention is an invention on the basis of the first invention, and is characterized in that: the freezing device includes a temperature correction component, and when the temperature in the storehouse is lower than the lower limit value in the above-mentioned third action, the temperature correction component Correction is performed to increase the lower limit value.

In the fourth invention, when the temperature in the storehouse reaches the lower limit value and the temperature in the storehouse is still lower than the lower limit value after switching to the third action under conditions such as relatively low outdoor temperature, the temperature correction means performs Increase the correction of the lower limit value. As a result, in the subsequent second operation, when the temperature in the chamber reaches the corrected lower limit value, it shifts to the third operation. Thereby, at the time of the third operation after that, since the interior temperature becomes a slightly higher temperature, it is possible to prevent the interior temperature from falling below the initial target temperature range.

The fifth invention is an invention based on the first invention, and is characterized in that: the freezing device includes a temperature correction component, and when the temperature in the storehouse is higher than the upper limit in the above-mentioned first action, the temperature correction component Correction is performed to lower the upper limit value.

In the fifth invention, even if the temperature in the storehouse reaches the upper limit value and the temperature in the storehouse is still higher than the upper limit value after switching to the first action under conditions such as relatively high outdoor temperature, the temperature correction means performs Lower the compensation of the upper limit value. As a result, in the subsequent third operation, when the temperature in the chamber reaches the corrected upper limit value, it switches to the first operation. Thereby, at the time of the first operation after that, since the interior temperature becomes a slightly lower temperature, it can be avoided that the interior temperature exceeds the initial target temperature range.

The 6th invention is the invention on the basis of the first invention, and it is characterized in that: the freezer includes a fan 16 in the storehouse, and the fan 16 in the storeroom is accommodated in the storehouse and sends air to the cooling heat exchanger 14 In the third operation, the storage fan 16 is operated at a speed lower than that in the first operation and the second operation.

[0023] In the sixth invention, when in the first action and the second action of the above-mentioned energy-saving operation, the indoor fan 16 is operated at a normal rotation speed. As a result, heat exchange is performed between the refrigerant flowing through the cooling heat exchanger 14 and the interior air sent by the interior fan 16 . As a result, the refrigerant absorbs heat from the air in the refrigerator, evaporates, and cools the interior of the refrigerator.

[0024] On the other hand, in the third operation in which the compressor 11 is stopped, the indoor fan 16 is operated at a speed lower than the rotational speed during the first operation or the second operation. As a result, the amount of heat generated from interior fan 16 accompanying the drive of interior fan 16 is reduced compared to the time of the first operation or the second operation described above. As a result, in the third operation, the time for the interior temperature to reach the upper limit is extended, so the stop time of the compressor 11 is also extended. Therefore, the power consumption of the refrigeration device during this energy-saving operation can be reduced.

The 7th invention is the invention on the basis of the first invention, it is characterized in that: the freezer includes a fan 16 in the storehouse, the fan 16 in the storeroom is accommodated in the storehouse and sends air to the cooling heat exchanger 14 , and the storage fan 16 is stopped only in the third operation.

[0026] In the seventh invention, when in the first operation and the second operation of the above-mentioned energy-saving operation, the indoor fan 16 is operated at a normal rotation speed. As a result, heat exchange is performed between the refrigerant flowing through the cooling heat exchanger 14 and the interior air sent by the interior fan 16 . As a result, the refrigerant absorbs heat from the air in the refrigerator, evaporates, and cools the interior of the refrigerator.

[0027] On the other hand, in the third operation in which the compressor 11 is stopped, the indoor fan 16 is stopped. Accordingly, since the interior fan 16 does not generate heat during the third operation, the time for the interior temperature to reach the upper limit is further extended. Therefore, the power consumption of the refrigeration device is further reduced during this energy-saving operation.

The eighth invention is based on the refrigerating device described below as a premise, that is, the refrigerating device includes a refrigerant circuit 10 connected to a cooling heat exchanger 14 and a compressor 11 for cooling the interior of the storehouse. A refrigerant is circulated in the refrigerant circuit 10 to perform a refrigeration cycle. And, the feature of this freezer is that: the freezer includes a capacity adjustment part 35 and a fan 16 in the storage, and the capacity adjustment part 35 adjusts the cooling capacity of the cooling heat exchanger 14, so that the temperature in the storage reaches the target temperature, the The fan 16 in the storage room is accommodated in the storage room and sends air to the cooling heat exchanger 14; the refrigeration device can realize the energy-saving operation of the first operation, the second operation and the third operation, and in the first operation, the above-mentioned The capacity adjustment unit 35 operates the above-mentioned compressor 11 while adjusting the cooling capacity of the cooling heat exchanger 14, stops the compressor 11 when the temperature in the storage room maintains the target temperature in the first operation in the second operation, and stops the compressor 11 in the third operation. When the compressor 11 is stopped due to the second action, the temperature in the storage reaches the upper limit of the target range including the above-mentioned target temperature, and the compressor 11 is started, and the first action is restarted; in the third action, The said interior fan 16 is operated at the speed lower than the speed in the said 1st operation|movement.

[0029] In the refrigeration system according to the eighth invention, the energy-saving operation in which the compressor 11 is intermittently operated is performed. Specifically, in this energy-saving operation, operations from the first operation to the third operation described below are repeated. In addition, at least a target temperature of the interior temperature and an upper limit value of a target range including the target temperature are set in the refrigeration apparatus.

[0030] First, in the first action, the compressor 11 is operated and the cooling capacity of the cooling heat exchanger 14 is adjusted by the capacity adjustment means 35. As a result, the temperature in the chamber gradually approaches the target temperature. In addition, in the first operation, interior fan 16 is operated at a normal rotation speed. When the interior temperature maintains the target temperature by the first operation, the second operation is performed, and the compressor 11 is stopped.

[0031] When the compressor 11 is stopped due to the above-mentioned second action, a third action is performed. In this third operation, the compressor 11 remains stopped. As a result, the refrigeration cycle is not performed in the refrigerant circuit 10, and the cooling of the interior of the refrigerator by the cooling heat exchanger 14 is substantially stopped. As a result, the temperature inside the chamber gradually increases from the target temperature. Then, when the interior temperature reaches the upper limit, the compressor 11 is restarted to restart the first operation.

[0032] Here, in the third operation in which the compressor 11 is in a stopped state in the present invention, the indoor fan 16 is operated at a speed lower than the rotational speed during the first operation. Thereby, the amount of heat generated from interior fan 16 accompanying the drive of interior fan 16 is reduced compared to the time of the first operation described above. As a result, in the third operation, the time for the interior temperature to reach the upper limit is extended, so the stop time of the compressor 11 is also extended. Therefore, the power consumption of the refrigeration device is reduced during this energy-saving operation.

The ninth invention is an invention based on any one of the first to eighth inventions, and is characterized in that: the freezing device can adjust the cooling capacity of the cooling heat exchanger 14 while using the capacity adjustment member 35. While continuously operating the normal operation of the above-mentioned compressor 11; the refrigeration device includes a suction temperature sensor (RS) that detects the temperature of the air in the storage that is sent to the above-mentioned cooling heat exchanger 14; During normal operation, when the temperature detected by the suction temperature sensor (RS) is within a predetermined temperature range including the target temperature, the above-mentioned energy-saving operation is switched.

[0034] In the refrigerating apparatus of the ninth invention, the compressor 11 is continuously operated during normal operation, and the cooling capacity of the cooling heat exchanger 14 is adjusted so that the internal temperature approaches the target temperature. In addition, a suction temperature sensor (RS) for detecting the temperature of the interior air sent into the cooling heat exchanger 14 is provided on the upstream side of the cooling heat exchanger 14 .

[0035] Here, in the present invention, an operation switching judgment of switching from normal operation to energy-saving operation is performed. Specifically, a comparison was made between the suction temperature measured by the suction temperature sensor (RS) and the target temperature during normal operation. In addition, when the suction temperature is not within the predetermined temperature range including the target temperature, it is necessary to quickly bring the temperature in the chamber close to the target temperature, so that the normal operation can be continued. On the other hand, when the suction temperature is within a predetermined temperature range including the target temperature, the interior temperature is already close to the target temperature, and it is not necessary to continuously operate the compressor 11, so the normal operation is switched to the energy-saving operation.

The tenth invention is an invention based on any one of the first to eighth inventions, and is characterized in that: the freezing device can adjust the cooling capacity of the cooling heat exchanger 14 while using the capacity adjustment member 35. While continuously operating the normal operation of the above-mentioned compressor 11; the refrigerating device includes a discharge temperature sensor (SS) that detects the temperature of the air in the storehouse that has passed through the above-mentioned cooling heat exchanger 14; During the normal operation, when the temperature detected by the discharge temperature sensor (SS) is within a predetermined temperature range including the target temperature, switching to the energy-saving operation is performed.

[0037] In the tenth invention, a discharge temperature sensor (SS) is provided on the downstream side of the cooling heat exchanger 14. The discharge temperature sensor (SS) detects the temperature of the interior air cooled in the cooling heat exchanger 14 .

[0038] Here, unlike the ninth invention described above, in the present invention, the transition from normal operation to energy-saving operation is performed by comparing the discharge temperature measured by the discharge temperature sensor (SS) with the target temperature. Conversion judgment. Specifically, the discharge temperature measured by the discharge temperature sensor (SS) was compared with the target temperature during normal operation. In addition, when the discharge temperature is not within the predetermined temperature range including the target temperature, it is necessary to quickly bring the chamber temperature close to the target temperature, so that the normal operation can be continued. On the other hand, when the discharge temperature is within a predetermined temperature range including the target temperature, the interior temperature is already close to the target temperature, and there is no need to continuously operate the compressor 11, so the normal operation is switched to the energy-saving operation.

The eleventh invention is an invention based on any one of the first to eighth inventions, and is characterized in that: the freezing device can perform cooling of the cooling heat exchanger 14 while utilizing the above-mentioned capacity adjustment member 35. In the energy-saving operation, when the time required for one cycle from the start of the first operation to the end of the third operation is less than a predetermined time, it is switched to the normal operation.

[0040] In the eleventh invention, the transition judgment from the energy-saving operation to the normal operation is performed based on the time required for one cycle from the start of the first operation to the end of the third operation in the energy-saving operation.

[0041] In addition, during the energy-saving operation, when the third operation of stopping the compressor 11 is performed under conditions such as a very high outdoor temperature, the temperature in the refrigerator tends to reach the upper limit of the target range. Accordingly, the time required for the third operation is shortened, and the time required for one cycle of energy-saving operation is also shortened. Therefore, when the energy-saving operation is continued under the above-mentioned conditions, the frequency of starting and stopping of the compressor 11 increases, resulting in shortening the life of the compressor 11 .

[0042] Therefore, in the present invention, in order to prolong the life of the compressor 11, when the time required for one cycle becomes shorter during the energy-saving operation, the energy-saving operation is switched to the normal operation. Specifically, when the time required for one cycle exceeds the specified set time, since the start-stop frequency of the compressor 11 becomes relatively low, the energy-saving operation can continue. On the other hand, when the time required for one cycle is less than the specified set time, the start-stop frequency of the compressor 11 becomes relatively high, so the energy-saving operation is switched to normal operation, and the compressor 11 can continue to operate.

[0043] The twelfth invention is an invention based on any one of the first to eighth inventions, and is characterized in that: when the cumulative number of starts and stops of the above-mentioned compressor 11 exceeds the specified number of times, the above-mentioned energy-saving operation is prohibited .

[0044] In the twelfth invention, as a result of repeated startup and shutdown of the compressor 11 due to energy-saving operation, etc., when the cumulative number of startup and shutdown times of the compressor 11 exceeds a predetermined number of times, energy-saving operation is prohibited.

(effect of invention)

[0045] According to the above-mentioned first invention, since the compressor 11 is intermittently operated during the energy-saving operation, the operating power of the compressor 11 can be reduced, and the energy-saving performance of the refrigeration system can be improved.

[0046] Especially in the present invention, once the temperature in the chamber drops to the lower limit value due to the second operation, the compressor 11 is stopped. And, at the time of the third operation, the compressor 11 is kept in a stopped state until the interior temperature reaches the upper limit value. Therefore, according to the present invention, compared with the case where the compressor is stopped once without reducing the temperature in the refrigerator to the lower limit value, the time for the temperature in the refrigerator to reach the upper limit value can be extended. This enables the compressor to be stopped for a correspondingly long period of time. Therefore, the operating power of the compressor 11 can be further reduced during the energy-saving operation, and the energy consumed by the refrigeration system can be effectively reduced.

Also, according to the present invention, because the capacity control of the cooling heat exchanger 14 and the start-stop control of the compressor 11 are carried out, the temperature in the storehouse is moved between the upper limit value and the lower limit value of the target range, Therefore, it is possible to prevent the temperature in the library from deviating from the target range. As a result, even during energy-saving operation, the interior of the refrigerator can be reliably cooled, so that the reliability of the refrigeration system can be improved.

[0048] Especially in the above-mentioned second invention, the flow regulating valve 35 is used to regulate the flow rate of the refrigerant sucked into the compressor 11, thereby adjusting the cooling capacity of the cooling heat exchanger 14. Thereby, since the refrigerant in the substantially wet vapor state accumulates in the entire area in the cooling heat exchanger 14 , the temperature of the air passing through the cooling heat exchanger 14 can be made uniform. That is, as shown in the present invention, when the cooling capacity of the cooling heat exchanger 14 is adjusted by the flow rate adjustment valve 35, the controllability of the interior temperature can be improved. As a result, at the time of the above-mentioned first operation, the temperature in the chamber can be quickly and surely brought close to the target temperature. In addition, in the second operation, the compressor 11 can be stopped when the interior temperature has definitely reached the lower limit value, and it is possible to prevent the interior temperature from falling below the lower limit value in the subsequent third operation.

[0049] Also, as described above, in the second operation, when it is assumed that the operating capacity (for example, operating frequency) of the compressor is increased to increase the cooling capacity of the cooling heat exchanger, the power consumption will also increase, and In contrast, in the present invention, since only the opening degree of the flow rate adjustment valve 35 is increased, the cooling capacity of the cooling heat exchanger 14 can be improved without increasing the above-mentioned power consumption.

[0050] Also, in the above-mentioned third invention, the opening degree of the flow rate regulating valve 35 at the end of the second operation of increasing the opening degree of the flow rate regulating valve 35 is maintained during the third operation, that is, until the first operation. The original state is maintained until the action is about to start. Therefore, according to the present invention, since the refrigerant circulation amount can be ensured from the time when the temperature in the storage reaches the upper limit and the first operation of restarting the compressor 11 starts, the air in the storage can be cooled quickly, and the air in the storage can be cooled in advance. Avoid the temperature in the library exceeding the upper limit.

[0051] Furthermore, in the above-mentioned fourth invention, when the temperature in the refrigerator is lower than the lower limit value in the third operation, correction is performed to increase the lower limit value. Thereby, at the time of the third operation after that, it is possible to prevent the interior temperature from falling below the initial target temperature range in advance.

[0052] On the other hand, in the above-mentioned fifth invention, when the interior temperature exceeds the upper limit value during the first operation, correction is performed to lower the upper limit value. Thereby, at the time of the first operation after that, it is possible to prevent the interior temperature from exceeding the initial target temperature range in advance.

[0053] Also, in the sixth or eighth invention described above, the storage fan 16 is operated at a low rotational speed in the third operation. Accordingly, the amount of heat generated by the interior fan 16 can be suppressed during the third operation, and the stop time of the compressor 11 can be extended. Therefore, the operating power of the compressor 11 can be further reduced during the energy-saving operation, and the energy-saving performance of the refrigeration system can be improved more effectively.

Also, if the fan in the library is completely stopped in the third action, it may cause deviations in the air temperature distribution in the library, and it may not be possible to correctly determine whether the temperature in the library has reached the upper limit. , That is, switch from the third action to the first action for judgment. On the other hand, in the present invention, only the rotation speed of the interior fan 16 is set at a low speed, so the temperature variation of the interior air can be reduced. Therefore, in the present invention, since it is possible to accurately determine the transition from the third operation to the first operation, it is possible to more reliably maintain the temperature in the refrigerator within the target range.

[0055] On the other hand, as described in the seventh invention, when the storage fan 16 is completely stopped only in the third action, since the heat generated by the storage fan 16 in the third action can be eliminated, it is possible to positively control the cooling effect of the second action. During the three operations, the temperature rise in the chamber is suppressed. Therefore, according to the seventh invention, the stop time of the compressor 11 can be extended, and the power consumption of the refrigeration system can be effectively reduced. In addition, since the operating power of the interior fan 16 is reduced by stopping the interior fan 16 in the third operation, the energy saving performance of the refrigeration system can be further improved.

[0056] Also, in the eighth invention, during the energy-saving operation, the temperature in the refrigerator is shifted between the target temperature and the upper limit value. Thereby, it is possible to prevent the temperature in the refrigerator from deviating from the allowable temperature range, and it is possible to improve the reliability of the refrigeration device.

[0057] In the ninth and tenth inventions, the judgment of switching from the normal operation to the energy-saving operation is automatically performed. In particular, in the ninth invention, the normal operation is continued until the intake temperature of the interior air before passing through the cooling heat exchanger 14 falls within the target temperature range. Here, since the intake temperature is the temperature of the interior air before being cooled by the cooling heat exchanger 14, this temperature is close to the actual interior temperature. Thereby, when switching to the energy-saving operation is judged based on the intake temperature, it is possible to switch to the energy-saving operation after the actual temperature in the refrigerator quickly approaches the target temperature range. Therefore, according to the ninth invention, it is possible to surely cool the stored goods in the refrigerator within the target temperature range, so that it is possible to perform operation in which the quality of the stored goods is emphasized.

[0058] On the other hand, in the tenth invention, the normal operation is continued until the discharge temperature of the interior air that has passed through the cooling heat exchanger 14 falls within the target temperature range. Here, since the discharge temperature is the temperature of the interior air cooled by the cooling heat exchanger 14, this temperature is slightly lower than the actual interior temperature. Thereby, when switching to the energy-saving operation is determined based on the discharge temperature, the energy-saving operation is switched to earlier than in the ninth invention. Therefore, according to the tenth invention, since the energy-saving operation is actively performed, it is possible to perform operation emphasizing energy-saving performance in this refrigeration system.

[0059] Also, in the eleventh invention, when the time required for one cycle of the energy-saving operation is shorter than a predetermined set time, the operation is automatically switched to normal operation. That is, in the present invention, when the frequency of starting and stopping of the compressor 11 is high during the energy-saving operation, the energy-saving operation is switched to the normal operation. Therefore, the number of times of starting and stopping of the compressor 11 can be reduced, and the life of the compressor 11 can be extended.

[0060] Furthermore, in the twelfth invention, when the cumulative number of starts and stops of the compressor 11 is higher than the maximum number of starts and stops, energy-saving operation is prohibited. Thereby, although the lifetime of the components of the compressor 11 is shortened, it is possible to prevent in advance the problem that the compressor 11 repeatedly starts and stops due to the energy-saving operation. Therefore, it is possible to increase the life of the compressor 11 and ensure the reliability of the refrigeration system.

Description of drawings

[0061] FIG. 1 is a piping diagram showing a schematic configuration of a refrigeration device in an embodiment.

Fig. 2 is a piping diagram showing the flow of refrigerant during operation of the refrigerating apparatus in the embodiment.

Fig. 3 is a time chart illustrating first to third operations when the refrigeration system in the embodiment is in an energy-saving operation mode.

Fig. 4 is a control flowchart for illustrating switching control between the normal operation mode and the energy-saving operation mode of the refrigeration system in the embodiment.

(Symbol Description)

1 freezer

10 refrigerant circuit

11 compressors

14 cooling heat exchanger (evaporator)

16 library fan

35 Suction proportional valve (flow adjustment valve, capacity adjustment parts)

Detailed ways

[0063] Below, embodiments of the present invention will be described in detail according to the accompanying drawings.

[0064] The refrigerating device 1 of this embodiment is a device for cooling the interior of a container used for marine transportation or the like. This refrigeration device 1 includes a refrigerant circuit 10 in which a refrigerant is circulated to perform a vapor compression refrigeration cycle.

[0065] In the refrigerant circuit 10, a compressor 11, a condenser 12, an expansion valve 13, and an evaporator 14 are connected as main components.

[0066] The above-mentioned compressor 11 is constituted by a fixed-capacity scroll compressor whose rotation speed of a compressor motor is constant. The above-mentioned condenser 12 is arranged outside the refrigerator, and constitutes a so-called air-cooled condenser. In the vicinity of the condenser 12, an external fan 15 for sending outside air to the condenser 12 is provided. In addition, heat exchange is performed between the outdoor air sent in by the outdoor fan 15 in the condenser 12 and the refrigerant. In addition, an outside temperature sensor (OS) is provided near the condenser 12 . The outside temperature sensor (OS) detects the temperature of outside air (outdoor air) sent into the condenser 12 .

[0067] The above-mentioned expansion valve 13 is composed of an electronic expansion valve whose opening can be adjusted. The opening degree of the expansion valve 13 is adjusted according to the degree of superheat of the refrigerant flowing out of the evaporator 14 .

[0068] The evaporator 14 is disposed in the storage of the container, and constitutes a cooling heat exchanger for cooling the storage. In the vicinity of the evaporator 14 is provided an in-storage fan 16 that sends the in-storage air to the evaporator 14 while circulating the in-storage air in the container warehouse. In addition, heat exchange is performed between the interior air sent by the interior fan 16 in the evaporator 14 and the refrigerant. Also, two temperature sensors are provided near the evaporator 14 . Specifically, a suction temperature sensor (RS) for detecting the temperature of the interior air sent into the evaporator 14 is provided on the upstream side of the interior air flow near the evaporator 14 . On the other hand, a discharge temperature sensor (SS) that detects the temperature of the interior air that has passed through the evaporator 14 is provided on the downstream side of the interior air flow in the vicinity of the evaporator 14 .

[0069] The discharge pipe 21 of the above-mentioned compressor 11 is connected to the inflow end of the above-mentioned condenser 12 through a check valve 31 and a discharge pressure regulating valve 32. The outflow end of the condenser 12 is connected to the expansion valve 13 via a receiver 33 , a first solenoid valve 41 , and a high-pressure side flow path 34 a of an economizer heat exchanger 34 . The suction pipe 22 of the compressor 11 is connected to the outlet end of the evaporator 14 through a suction proportional valve 35 . The inflow end of the evaporator 14 is connected to the above-mentioned expansion valve 13 .

[0070] The energy-saving heat exchanger 34 is a device for exchanging heat between the refrigerant flowing through the high-pressure side flow path 34a and the refrigerant flowing through the low-pressure side flow path 34b. The inflow end of the low-pressure side channel 34b is connected between the condenser 12 and the accumulator 33 through a capillary tube 36 and a second solenoid valve 42 . In addition, the outflow end of the low-pressure side flow path 34b is connected to the intermediate suction port 11a of the compressor 11 described above. In the compression mechanism of the compressor 11, the intermediate suction port 11a opens on the path of the refrigerant compression process.

[0071] The suction proportional valve 35 constitutes a flow rate adjustment valve that adjusts the refrigerant circulation amount in the refrigerant circuit 10 by adjusting the amount of refrigerant sucked by the compressor 11. That is, the suction proportional valve 35 constitutes a capacity adjusting means that adjusts the cooling capacity of the evaporator 14 by adjusting the refrigerant circulation amount. The opening degree of the suction proportional valve 35 is adjusted according to the temperature detected by an internal temperature sensor not shown in the drawing, which is installed in the container warehouse.

[0072] In the refrigerant circuit 10, a first defrosting pipe 23, a second defrosting pipe 24, a discharge gas bypass pipe 25, and a liquid injection pipe 26 are also connected.

The above-mentioned first defrosting pipe 23 and the second defrosting pipe 24 are used for the defrosting operation in which the refrigerant ejected from the compressor 11 is introduced into the above-mentioned evaporator 14 to melt the frost attached to the evaporator 14. pipeline. One end of the first defrosting pipe 23 and the second defrosting pipe 24 are respectively connected between the check valve 31 and the discharge pressure regulating valve 32, and their respective other ends are respectively connected to the above-mentioned expansion valve 13 and the evaporator 14 between. A third electromagnetic valve 43 that is opened during a defrosting operation is provided on the first defrosting pipe 23 . The second defrosting pipe 24 is provided with a fourth solenoid valve 44 and a drain pan heater 37 which are opened during defrosting operation. The drip tray heater 37 is arranged in the drip tray, and the drip tray is used to receive the frost or dew peeled off from the surface of the above-mentioned evaporator 14 in the container warehouse. Thus, when the refrigerant discharged from the compressor 11 flows through the drip pan heater 37 during the defrosting operation, the frost or dew ice collected in the drip pan is absorbed by the refrigerant discharged from the compressor 11. Melts when heated. In addition, during this defrosting operation, the above-mentioned discharge pressure adjustment valve 32 is set to a fully closed state.

[0074] The discharge gas bypass pipe 25 is a pipe for returning the refrigerant discharged from the compressor 11 to the suction side of the compressor 11 when the cooling capacity of the evaporator 14 is excessive. In addition, the discharge gas bypass pipe 25 also serves as an oil return pipe for returning the refrigerating machine oil contained in the refrigerant discharged from the compressor 11 to the suction side of the compressor 11 . One end of the discharge gas bypass pipe 25 is connected between the check valve 31 and the fourth solenoid valve 44 , and the other end is connected between the evaporator 14 and the suction proportional valve 35 . The discharge gas bypass pipe 25 is provided with a fifth electromagnetic valve 45 which is appropriately opened according to operating conditions.

[0075] The liquid injection pipe 26 is a so-called liquid injection pipe for returning the liquid refrigerant condensed in the condenser 12 to the suction side of the compressor 11. One end of the liquid injection pipe 26 is connected between the first electromagnetic valve 41 and the energy-saving heat exchanger 34 , and the other end is connected between the suction proportional valve 35 and the compressor 11 . A sixth electromagnetic valve 46 that is appropriately opened according to operating conditions is provided on the liquid injection pipe 26 .

[0076] The refrigeration device 1 is further provided with a controller (not shown). In this controller, the target temperature in the container warehouse is set as the set temperature TS. In addition, when the controller is in the energy-saving operation mode described in detail below, an upper limit value and a lower limit value are set as the temperature target range in the refrigerator. Specifically, an upper limit temperature Tmax serving as an upper limit of the interior temperature target range and a lower limit temperature Tmin serving as a lower limit are set in the controller. Furthermore, the controller is provided with temperature correction means for correcting the upper limit temperature Tmax and the lower limit temperature Tmin in the energy-saving operation mode.

-running action-

This refrigerating device 1 can perform a freezing operation in which the temperature in the container is cooled to a temperature lower than zero degrees Celsius and then freezes the stored goods in the warehouse, and can cool the temperature in the warehouse to a temperature higher than zero degrees Celsius. The refrigerating operation (chilled operation) in which stored goods are refrigerated, and the above-mentioned defrosting operation. Here, the refrigeration operation which is the characteristic of this invention is demonstrated.

[0078] During the refrigeration operation described above, a normal operation mode and an energy-saving operation mode can be performed. The normal operation mode is an operation mode in which the compressor 11 is continuously operated, the air in the refrigerator is continuously cooled by the evaporator 14, and the stored goods in the refrigerator are refrigerated. On the other hand, in the above-mentioned energy-saving operation mode, the compressor 11 is intermittently operated, and the air in the refrigerator is semi-continuously cooled by the evaporator 14, thereby achieving energy saving of the refrigeration device 1 while refrigerating the stored goods in the refrigerator. operating mode.

[0079] <normal operation mode>

First, the normal operation mode of the refrigeration system 1 will be described with reference to FIG. 2 . In this normal operation mode, the compressor 11 is continuously operated and the opening degrees of the expansion valve 13 and the suction proportional valve 35 are appropriately adjusted. Also, in this normal operation mode, in principle, the above-mentioned first and second solenoid valves 41, 42 are opened, while the above-mentioned third to sixth solenoid valves 43, 44, 45, 46 are closed, and the external fan 15 And the indoor fan 16 operates at a normal rotation speed.

[0080] The refrigerant compressed in the compressor 11 flows into the condenser 12 through the discharge pipe 21. In the condenser 12, the refrigerant releases heat to the outdoor air and then condenses. Thereafter, part of the refrigerant flows into the high-pressure side flow path 34a of the energy-saving heat exchanger 34 through the accumulator 33, and the remaining part flows into the low-pressure side flow of the energy-saving heat exchanger 34 after being decompressed while passing through the capillary tube 36. Road 34b.

[0081] In the energy-saving heat exchanger 34, the refrigerant flowing through the low-pressure side flow path 34b absorbs heat from the refrigerant flowing through the high-pressure side flow path 34a, and evaporates. That is, subcooling of the refrigerant flowing through the high-pressure side flow path 34 a is performed in the energy-saving heat exchanger 34 . The refrigerant evaporated in the low-pressure side flow path 34b is sucked into the intermediate suction port 11a of the compressor 11 .

[0082] The refrigerant subcooled in the high-pressure side flow path 34a flows into the evaporator 14 after passing through the expansion valve 13 after being decompressed. In the evaporator 14, the refrigerant evaporates after absorbing heat from the air in the storage. As a result, cooling in the container warehouse is performed. The refrigerant evaporated in the evaporator 14 is sucked by the compressor 11 after passing through the suction proportional valve 35 .

[0083] <Energy Saving Operation Mode>

Next, the energy-saving operation mode of the refrigeration system 1 will be described. In this energy-saving operation mode, the control operations from the first operation to the third operation shown in FIG. 3 are repeated by the controller. In addition, the basic flow of refrigerant in the refrigeration system 1 during this energy-saving operation mode is the same as that in the above-mentioned normal operation mode.

[0084] In the first operation, the compressor 11 is operated and the indoor fan 16 is operated at a normal rotation speed. In addition, in the first operation, the cooling capacity of the evaporator 14 is adjusted so that the temperature in the refrigerator reaches the set temperature TS.

[0085] Specifically, in the first operation, the opening degree of the suction proportional valve 35 is adjusted by PI control based on the set temperature TS and the temperature detected by the internal temperature sensor. As a result, the refrigerant circulation rate of the refrigerant circuit 10 is adjusted according to the opening degree of the suction proportional valve 35, and the cooling capacity of the evaporator 14 is also adjusted.

[0086] In addition, when the cooling capacity of the evaporator 14 is adjusted while reducing the opening degree of the suction proportional valve 35 as described above, the refrigerant tends to be in a wet vapor state in the entire area of the evaporator 14. Therefore, it is assumed that when the cooling capacity of the evaporator is adjusted by adjusting the opening degree of the electronic expansion valve on the inflow side of the evaporator, the refrigerant flowing through the evaporator is roughly in the state of dry vapor and flows between the inflow end and the outflow end of the evaporator. In contrast, when the cooling capacity of the evaporator 14 is adjusted while reducing the opening of the suction proportional valve 35, the temperature of the refrigerant between the inflow end and the outflow end of the evaporator 14 The distribution is evened out. As a result, since the air in the refrigerator is cooled relatively uniformly, the controllability of the temperature in the refrigerator by the evaporator 14 is also improved.

[0087] The second action is performed after the above-mentioned first action. In addition, in this embodiment, since the set time set by the controller has elapsed since the first operation start time t0, the first operation is switched to the second operation. This set time is a sufficient time interval set to maintain the interior temperature at the set temperature TS by cooling the evaporator 14, and this set time is set to about 2 minutes in this embodiment. That is, in the energy-saving operation mode, when 2 minutes have passed from time t0 to time t1 at which it can be determined that the temperature in the refrigerator has indeed maintained the target temperature, the first operation is switched to the second operation.

[0088] In the second action, when the cooling capacity of the evaporator 14 gradually increases after time t1, the temperature in the storage keeps dropping. Specifically, in the second operation, the compressor 11 continues to operate, and the indoor fan 16 also operates at a normal rotation speed. On the other hand, in the second operation, the opening degree of the suction proportional valve 35 gradually increases after time t1. As a result, the circulation amount of the refrigerant in the refrigerant circuit 10 gradually increases, and the cooling capacity of the evaporator 14 also gradually increases.

[0089] When the opening of the above-mentioned suction proportional valve 35 is adjusted so that the temperature in the storehouse decreases and reaches the lower limit temperature Tmin, then the second action is switched to the third action. That is, the third operation starts from time t2 when the temperature in the chamber reaches the lower limit temperature Tmin. In addition, in this second operation, the opening degree adjustment of the suction proportional valve 35 is performed stepwise so that the opening degree increases by 10% every 10 seconds from time t1. As a result, since the temperature in the chamber drops relatively smoothly, the phenomenon that the temperature in the chamber falls below the lower limit temperature Tmin after switching from the second operation to the third operation, that is, the occurrence of so-called undershoot, is suppressed.

[0090] In the third operation, the compressor 11 immediately stops. As a result, since the refrigerating cycle in the refrigerant circuit 10 is also stopped, and the cooling of the interior by the evaporator 14 is substantially stopped, the interior temperature gradually rises. In addition, in the third operation, the storage fan 16 has a low rotation speed lower than the normal rotation speed. As mentioned above, when the rotation speed of the storage fan 16 is lower than the speed in the first operation or the second operation, since the heat generated by the operation of the motor of the storage fan 16 is suppressed, in the third operation, the storage room The rate of temperature rise also slows down. In addition, when the rotation speed of the storage fan 16 is changed, the storage fan 16 is operated at a low rotation speed immediately after the storage fan 16 is once stopped in order to alleviate the sudden torque (torque) fluctuation of the storage fan 16 . In addition, in this third operation, the opening degree of the suction proportional valve 35 is maintained at the opening degree at the end of the second operation (time t2).

[0091] When the temperature in the chamber gradually rises due to the above-mentioned third action and reaches the upper limit temperature Tmax, then switch from the third action to the first action again. That is, the first operation starts from time t3 when the temperature in the chamber reaches the upper limit temperature Tmax. As a result, the compressor 11 is restarted, and the storage fan 16 is operated at a normal rotation speed. In addition, the opening of the suction proportional valve 35 during the third action is taken as the initial opening of the first action, and the opening is then adjusted by PI control based on the set temperature TS and the temperature detected by the internal temperature sensor. adjust. Accordingly, the opening degree of the suction proportional valve 35 at the start of the first operation is the same as the opening degree at the end of the second operation for increasing the cooling capacity of the evaporator 14 and cooling the interior air. As a result, the amount of refrigerant circulation is ensured from the start of the first operation of restarting the compressor 11 after the interior temperature reaches the upper limit temperature Tmax, and the interior temperature gradually converges to the target temperature again after the air in the chamber is rapidly cooled. .

The learning control of <upper limit temperature and storehouse temperature>

In the above-mentioned energy-saving operation mode, if the cooling capacity of the evaporator 14 is increased in the above-mentioned second operation under conditions such as relatively low outdoor temperature, the interior temperature tends to drop. Accordingly, even when the temperature in the refrigerator reaches the lower limit temperature Tmin in the second operation and then shifts to the third operation, the temperature in the refrigerator may fall below the lower limit temperature Tmin. On the other hand, when the compressor 11 is stopped in the above-mentioned third operation under the condition that the outdoor temperature is relatively high, the interior temperature tends to rise. Therefore, even when the temperature in the refrigerator reaches the upper limit temperature Tmax in the third operation and then the first operation is switched, the temperature in the refrigerator may exceed the upper limit temperature Tmax. In order to avoid the phenomenon that the temperature in the refrigerator deviates from the target range due to the above-mentioned outdoor temperature conditions, etc., in the refrigeration device 1 of this embodiment, the following learning control (learning control) is performed when in the energy-saving operation mode.

[0093] In the energy-saving operation mode, it is determined whether the internal temperature is lower than the lower limit temperature Tmin within a predetermined determination time (for example, 60 seconds) from the start of the third operation (time t2). Specifically, when the outdoor temperature is relatively low, when the internal temperature falls below the lower limit temperature Tmin during the above judgment time, the controller detects this and sets a flag. In addition, even if the temperature in the chamber falls below the lower limit temperature Tmin several times during the judgment time of 60 seconds, this flag is established only once. Also, when the temperature in the storage does not drop below the lower limit temperature Tmin during the judgment time of 60 seconds during the third action of the next cycle, the flag is reset. Then, when the flag is established three times in a row while the energy-saving operation is continued, the temperature correction means of the controller performs correction to raise the lower limit temperature Tmin. In the correction by the temperature correction means, for example, when the current minimum temperature Tmin is 4.5°C, 4.6°C, which is a value obtained by adding a correction value of 0.1°C to Tmin, is set as the new minimum temperature Tmin'. As a result, in the second operation of the corrected cycle, the third operation can be avoided when the internal temperature reaches the corrected lower limit temperature Tmin' (4.6°C), so that the internal temperature can be prevented from falling to the original target. The lower limit of the range is lower than the lower limit temperature Tmin (4.5°C).

[0094] In addition, in the energy-saving operation mode, whether the temperature in the storage room exceeds The judgment of the upper limit temperature Tmax is realized. Specifically, under the condition that the outdoor temperature is relatively high, when the internal temperature is above the upper limit temperature Tmax during the above-mentioned judgment time, the controller detects this and sets a flag. Also, even if the temperature in the chamber exceeds the upper limit temperature Tmax several times during the 30 seconds of the judgment time, this flag is established only once. Also, in the third operation of the next cycle, when the internal temperature does not exceed the upper limit temperature Tmax again within 30 seconds of the judgment time, this flag is reset. Then, when the flag is established three times in a row while the energy-saving operation is continued, the temperature correction means of the controller performs correction to lower the upper limit temperature Tmax. In the correction by the temperature correction means, when the current upper limit temperature Tmax is, for example, 5.5°C, 5.4°C, which is a value obtained by subtracting a correction value of 0.1°C from this Tmax, is set as the new upper limit temperature Tmax' . As a result, in the third operation of the cycle after correction, the first operation is switched to when the internal temperature reaches the corrected upper limit temperature Tmax' (5.4°C), so the internal temperature can be prevented from exceeding the initial target range. The upper limit is the upper limit temperature Tmax (5.5°C).

[0095] Also, especially under the condition that the outdoor temperature is very high, even if the above-mentioned learning control is performed, it can be expected that the temperature in the storage room will exceed the upper limit temperature Tmax. Thus, when the flag is established five times in a row after 30 seconds of the determination time after the start of the first operation as described above, the operation mode is automatically switched from the energy-saving operation mode to the above-mentioned normal operation mode. As a result, under the condition that the above-mentioned outdoor temperature is extremely high, the temperature in the refrigerator is reliably maintained at the target temperature by the normal operation mode.

[0096] <Automatic switching control between normal operation and energy-saving operation>

In addition, in the refrigerating apparatus of this embodiment, the following switching is automatically performed between the above-mentioned normal operation mode and the energy-saving operation mode.

[0097] As shown in FIG. 4, the normal operation is first performed, and then in step S1, a comparison is made between the suction temperature RT measured by the suction temperature sensor (RS) and the target temperature TS in the storage. Here, when the suction temperature RT is out of the range of the target temperature TS±3.0° C., the normal operation is continued because it is necessary to quickly bring the interior temperature close to the target temperature range. On the other hand, when the suction temperature RT is within the range of the target temperature TS ± 3.0° C., since the temperature in the refrigerator has been maintained within the target temperature range, there is no need to continuously operate the compressor 11, so the transition to step S2 is performed. Energy-saving operation.

[0098] In the subsequent energy-saving operation, the time required for one cycle from the start of the above-mentioned first operation to the end of the third operation is measured. And, in step S3, a comparison is made between the time required for this one cycle and the preset time (for example, 180 seconds).

[0099] However, when the compressor 11 is stopped in the third operation under the condition that the outdoor temperature is very high, the time (t3-t2) for the air in the chamber to reach the upper limit temperature Tmax from the lower limit temperature Tmin shown in FIG. It is extremely short, so the time required for one cycle in energy-saving operation is also shortened. Therefore, when the energy-saving operation is continued under the above-mentioned conditions, the life of the compressor 11 is shortened because the frequency of starting and stopping of the compressor 11 increases. Thus, in step S3, when the outdoor temperature is very high and the time required for one cycle is less than the set time, the energy-saving operation ends (step S4), and normal operation resumes (step S5). As a result, since the compressor 11 is in a continuous operation state, it is possible to improve the life of the compressor 11 .

[0100] Also, in step S5, the normal operation is started, and at the same time, the outside temperature OT1 is measured by the outside temperature sensor (OS) at this time. Thereafter, in step S6, the external temperature OT2 that appears immediately after the normal operation is started is appropriately measured. And, when the current outside temperature OT2 is lower than the outside temperature OT1 at the start of normal operation by a predetermined set temperature (for example, 5°C) or more, since the outside temperature has dropped since the last energy-saving operation ended, If the temperature is above 5°C, it is considered that the energy-saving operation can be restarted, so it returns to step S1 to judge the start of energy-saving operation again. On the other hand, when the current outdoor temperature OT2 is lower than the value of the outdoor temperature OT1 at the start of normal operation and does not exceed the specified temperature, it can be considered that the outdoor temperature is still too high for energy-saving operation, and the process does not proceed to step S1. .

[0101] In addition, in this refrigeration device 1, the above-mentioned defrosting operation is performed periodically (for example, every 4 hours) in various operation modes. As a result, the normal operation is performed after the defrosting operation is completed, and at step S1 , the start determination of the energy-saving operation is performed.

<Prohibition Control of Energy Saving Operation>

Also, in the refrigerating apparatus of this embodiment, when the accumulative start-stop times of the compressor 11 exceed the predetermined set times due to the above-mentioned energy-saving operation, etc., only the normal operation is allowed, and the energy-saving operation is prohibited. Specifically, in this refrigerating apparatus, the number of ON/OFF times of the electromagnetic switch that controls the start and stop of the compressor 11 is counted step by step. In addition, at this time, one action of switching the electromagnetic switch from OFF to ON is counted as one start and stop. On the other hand, a predetermined upper limit number of times (for example, 200,000 times) is set in the controller according to the specifications of the compressor 11 . Furthermore, when the number of start and stop of the compressor 11 exceeds 200,000 due to the above-mentioned energy-saving operation, etc., the energy-saving operation is prohibited, and only normal operation can be performed.

-Effect of embodiment-

In the above-described embodiment, the following effects are exhibited.

[0104] According to the above-described embodiments, the compressor 11 is intermittently operated in the energy-saving operation mode, so that the operating power of the compressor 11 can be reduced, and the energy-saving performance of the refrigeration device 1 can be improved.

[0105] Especially in the energy-saving operation mode of the above-mentioned embodiment, as shown in FIG. 3 , the compressor 11 is stopped once the temperature inside the refrigerator drops to the lower limit temperature Tmin due to the second operation. As a result, after the compressor 11 is stopped, the duration of the third operation in which the interior temperature reaches the upper limit temperature Tmax can be extended, so the operating time of the compressor 11 in the energy-saving operation mode can be effectively shortened. Therefore, the operating power of the compressor 11 in the energy-saving operation mode can be significantly reduced, and the energy-saving performance of the refrigeration apparatus 1 can also be effectively improved.

[0106] Also, in the above-mentioned energy-saving operation mode, the capacity control of the evaporator 14 or the start-stop control of the compressor 11 are carried out, so that the temperature in the storehouse is at the lower limit of the allowable temperature range of the storehouse temperature, that is, the lower limit temperature Tmin, and the upper limit value of the allowable temperature range, that is, the upper limit temperature Tmax. Accordingly, during the energy-saving operation mode, it is possible to prevent the internal temperature from deviating from the allowable temperature range, and to improve the reliability of the refrigeration device 1 .

[0107] Furthermore, in this embodiment, the cooling capacity of the evaporator 14 is adjusted by adjusting the opening of the suction proportional valve 35. As mentioned above, when the cooling capacity of the evaporator 14 is adjusted while adjusting the opening of the suction proportional valve 35, since the refrigerant in the entire area of the evaporator 14 is in a wet vapor state, the evaporator 14 can be used to cool the air in the store. For more uniform cooling. As a result, in the first operation of the energy-saving operation mode, the temperature in the refrigerator can be quickly and reliably brought close to the target temperature. Also, since the compressor 11 can be stopped when the interior temperature reliably reaches the lower limit during the second operation, it is possible to prevent the interior temperature from falling below the lower limit during the subsequent third operation.

[0108] Also, even if the opening of the suction proportional valve 35 is adjusted to enhance the cooling capacity of the evaporator 14 during the second action, the operating capacity of the compressor 11 does not change. The cooling capacity of the evaporator 14 can be improved without increasing the operating power of the compressor 11 . Therefore, the energy saving performance of the refrigeration device 1 can be further improved.

[0109] Furthermore, in the above-described embodiment, the interior fan 16 is operated at a low rotation speed lower than that in the first operation or the second operation during the third operation. Thus, in the third operation, since the heat generated by the motor driving of the interior fan 16 can be suppressed, the continuation of the third operation in which the interior temperature reaches the upper limit temperature Tmax can be extended after the compressor 11 is stopped. time. Therefore, the stop time of the compressor 11 can be extended, and the energy saving performance of the refrigeration apparatus 1 can be further improved.

[0110] Also, in the energy-saving operation mode of the above-mentioned embodiment, so-called learning control is performed, that is, the upper limit temperature Tmax or the lower limit temperature Tmin is corrected according to the temperature in the refrigerator. Therefore, the phenomenon that the temperature in the refrigerator is lower than the lower limit temperature Tmin or higher than the upper limit temperature Tmax can be avoided in advance, so it is also possible to reliably prevent the temperature in the refrigerator from deviating from the allowable temperature range in the energy-saving operation mode. Therefore, the reliability of the refrigeration device 1 can be further improved.

[0111] Furthermore, in the above-described embodiment, the determination of switching from the normal operation to the energy-saving operation is performed based on the intake temperature RT of the interior air before flowing into the cooling heat exchanger 14. Then, the normal operation is continued until the suction temperature RT falls within the target temperature range. Here, since the intake temperature RT is the temperature of the interior air before being cooled by the cooling heat exchanger 14, it is close to the actual interior temperature. As a result, when switching from normal operation to energy-saving operation is judged based on the intake temperature RT, it is possible to switch to energy-saving operation after quickly bringing the actual interior temperature within the target temperature range. Therefore, since the stored goods in the refrigerator can be surely cooled within the target temperature range, it is possible to perform operation in which the quality of the stored goods is emphasized in the refrigeration apparatus 1 .

[0112] On the other hand, in the above-described embodiments, when the time required for one cycle of the energy-saving operation is shorter than the predetermined set time, the operation is automatically switched to the normal operation. That is, in the above-mentioned embodiment, when the frequency of start and stop of the compressor 11 is high during the energy-saving operation, the energy-saving operation is switched to the normal operation. Therefore, the number of times of starting and stopping of the compressor 11 can be reduced, and the life of the compressor 11 can be extended.

<Other Control Examples>

In the refrigeration apparatus 1 of the above-described embodiment, the following control can also be performed.

[0114] In the above-described embodiment, in the third operation of stopping the compressor 11, the heat generated by the interior fan 16 is suppressed by operating the interior fan 16 at a low speed. However, in this 3rd operation|movement, the indoor fan 16 may be stopped completely. At this time, since the fan motor of the interior fan 16 does not generate heat during the third operation, it is possible to actively suppress the increase in the interior temperature during the third operation. Therefore, the stop time of the compressor 11 can be extended further, and the power consumption of this refrigeration apparatus 1 can be effectively reduced. In addition, since the operating power of the interior fan 16 is also reduced by stopping the interior fan 16 in the third operation, the energy saving performance of the refrigeration device 1 can be further improved.

[0115] In the energy-saving operation mode of the above embodiment, the cooling capacity of the evaporator 14 is gradually increased by gradually increasing the opening degree of the suction proportional valve 35 in the second operation. However, it is also possible to perform control to set the opening degree of the suction proportional valve 35 to twice the current opening degree immediately after the start of the second operation, or to perform control based on the detection value of the interior temperature sensor with the lower limit temperature Tmin as the target. PI control is used to increase the cooling capacity of the evaporator 14 .

[0116] Also, in the energy-saving operation mode of the above-mentioned embodiment, the lower limit temperature Tmin is set, and the compressor 11 is stopped once the temperature in the storage is lowered to the lower limit temperature Tmin in the second operation. However, it is also possible to stop the compressor 11 without lowering the interior temperature during the second operation. At this time, since the third operation ends when the interior temperature reaches the upper limit temperature Tmax from the set temperature TS after the compressor 11 stops, the stop time of the compressor 11 is shorter than that of the above-described embodiment. However, also at this time, by operating the interior fan 16 at a rotational speed lower than that of the first operation in the third operation, the heat generation accompanying the driving of the interior fan 16 can be suppressed, and the temperature generated in the third operation can be reduced. The temperature rise rate in the chamber during operation. Therefore, also in this example, it is possible to prolong the stop time of the compressor 11 , so energy saving of the refrigeration system 1 can be realized with the power reduction of the compressor 11 .

[0117] Furthermore, in the energy-saving operation mode of the above-mentioned embodiment, the opening degree of the suction proportional valve 35 at the end of the second operation is maintained at the current state until the end of the third operation, that is, until the start of the first operation. However, in this third operation, the opening degree of the suction proportional valve 35 may be fixed as a predetermined opening degree regardless of the opening degree of the suction proportional valve 35 at the end of the second operation, or may be adjusted according to, for example, the temperature inside the refrigerator. The opening degree of the suction proportional valve 35 is adjusted.

[0118] In addition, in the energy-saving operation mode of the above-mentioned embodiment, the suction proportional valve 35 is used as the capacity adjusting means for adjusting the cooling capacity of the evaporator 14. However, it is also possible to adjust the cooling capacity of the evaporator 14 by, for example, adjusting the opening degree of the electronic expansion valve on the upstream side of the evaporator 14 or adjusting the capacity of the compressor.

[0119] Furthermore, in the above-described embodiment, the judgment of switching from the normal operation to the energy-saving operation is performed based on the intake temperature RT of the interior air sent into the cooling heat exchanger 14. However, when the discharge temperature ST of the interior air that has passed through the cooling heat exchanger 14 is measured by the above-mentioned discharge temperature sensor (SS), and the discharge temperature ST is within a predetermined set temperature range including the target temperature, It is also possible to switch from normal operation to energy-saving operation. Since the discharge temperature ST is lower than the suction temperature RT, the transition from the normal operation to the energy-saving operation at this time is earlier than in the above-mentioned embodiment. That is, in this example, the energy-saving operation is performed more frequently than in the above-described embodiment. Therefore, in the refrigerating apparatus 1 of this example, it is possible to perform operation emphasizing energy saving.

[0120] Also, in the above-mentioned embodiment, under the condition of energy-saving operation, when the time required for a cycle from the beginning of the first action to the end of the third action is lower than the specified set time, it will switch to normal operation . However, during the energy-saving operation, when the time required for the third operation in which the compressor 11 is stopped falls below a predetermined set time, the operation may be switched to normal operation. At this time, the start-stop frequency of the compressor 11 can also be reduced, and the service life of the compressor 11 can be improved.

[0121] Furthermore, the above-described embodiments are ideal examples in nature and are not intended to limit the invention, its applicability, or the scope of its use.

(Industrial Utilization Possibility)

[0122] As described above, the present invention is useful for an energy-saving operation method of a refrigeration device having a cooling heat exchanger for cooling the storage.

Claims (12)

1. refrigerating plant comprises being connected with being used for the cooling heat exchanger that cools off in the storehouse and the refrigerant loop of compressor are made cold-producing medium circulate in this refrigerant loop and carry out kind of refrigeration cycle, it is characterized in that:

This refrigerating plant comprises the capacity adjustment parts, and these capacity adjustment parts are regulated the cooling capacity of above-mentioned cooling heat exchanger, so that storehouse temperature reaches target temperature,

This refrigerating plant can realize carrying out first action, the energy-saving operation of second action and the 3rd action, the cooling capacity of in this first action, utilizing on one side aforementioned capabilities the to regulate parts adjusting cooling heat exchanger above-mentioned compressor that turns round, utilizing aforementioned capabilities to regulate parts when storehouse temperature is kept target temperature in above-mentioned first action in this second action improves the cooling capacity of above-mentioned cooling heat exchanger, and storehouse temperature is reduced to comprises above-mentioned target temperature and after the lower limit of interior target zone, compressor is stopped, in the 3rd action when compressor since above-mentioned second action stops the back storehouse temperature when reaching the higher limit of above-mentioned target zone startup compressor restart to carry out first and move.

2. refrigerating plant according to claim 1 is characterized in that:

Aforementioned capabilities is regulated parts and is made of flow rate regulating valve, and this flow rate regulating valve is connected on the refrigerant loop and to being regulated by the flow of the cold-producing medium that compressor sucked,

In above-mentioned second action, the aperture that increases above-mentioned flow rate regulating valve improves the cooling capacity of above-mentioned cooling heat exchanger.

3. refrigerating plant according to claim 2 is characterized in that:

In above-mentioned the 3rd action, the aperture the when aperture of flow rate regulating valve keeps above-mentioned second release.

4. refrigerating plant according to claim 1 is characterized in that:

This refrigerating plant comprises temperature revisal parts, when storehouse temperature is lower than lower limit in above-mentioned the 3rd action, and the revisal that these temperature revisal parts improve this lower limit.

5. refrigerating plant according to claim 1 is characterized in that:

This refrigerating plant comprises temperature revisal parts, when storehouse temperature is higher than higher limit in above-mentioned first action, and the revisal that these temperature revisal parts reduce this higher limit.

6. refrigerating plant according to claim 1 is characterized in that:

This refrigerating plant comprises the storehouse internal fan, and this storehouse internal fan is incorporated in Ku Nei and air is delivered to cooling heat exchanger,

In above-mentioned the 3rd action, make above-mentioned storehouse internal fan to turn round than the low speed of speed that reaches in second action in above-mentioned first action.

7. refrigerating plant according to claim 1 is characterized in that:

This refrigerating plant comprises the storehouse internal fan, and this storehouse internal fan is incorporated in Ku Nei and air is delivered to cooling heat exchanger,

Only in above-mentioned the 3rd action, above-mentioned storehouse internal fan is stopped.

8. refrigerating plant comprises being connected with being used for the cooling heat exchanger that cools off in the storehouse and the refrigerant loop of compressor are made cold-producing medium circulate in this refrigerant loop and carry out kind of refrigeration cycle, it is characterized in that:

This refrigerating plant comprises capacity adjustment parts and storehouse internal fan, and these capacity adjustment parts are regulated the cooling capacity of cooling heat exchanger, so that storehouse temperature reaches target temperature, this storehouse internal fan is incorporated in Ku Nei and air is delivered to cooling heat exchanger,

This refrigerating plant can realize carrying out the energy-saving operation of first action, second action and the 3rd action; The cooling capacity of in this first action, utilizing on one side aforementioned capabilities the to regulate parts adjusting cooling heat exchanger above-mentioned compressor that turns round; In this second action, when keeping target temperature in first action, storehouse temperature stops compressor; In the 3rd action when compressor since above-mentioned second move stop after storehouse temperature reach startup compressor when comprising the higher limit of above-mentioned target temperature in interior target zone; Restart to carry out first action

In above-mentioned the 3rd action, make above-mentioned storehouse internal fan to turn round than the low speed of speed in above-mentioned first action.

9. according to each the described refrigerating plant in the claim 1～8, it is characterized in that:

This refrigerating plant can carry out while the cooling capacity common running of running above-mentioned compressor continuously that utilizes aforementioned capabilities adjusting parts adjusting cooling heat exchanger,

This refrigerating plant comprises the inlet temperature sensor, and this inlet temperature sensor detects the temperature of air in the storehouse that is sent to above-mentioned cooling heat exchanger,

In above-mentioned common running, when the detected temperatures of inlet temperature sensor is comprising in the set point of temperature scope of above-mentioned target temperature, switch to above-mentioned energy-saving operation.

10. according to each the described refrigerating plant in the claim 1～8, it is characterized in that:

This refrigerating plant can carry out while the cooling capacity common running of running above-mentioned compressor continuously that utilizes aforementioned capabilities adjusting parts adjusting cooling heat exchanger,

This refrigerating plant comprises the ejection temperature sensor, and this ejection temperature sensor detects the temperature by air in the storehouse of above-mentioned cooling heat exchanger,

In above-mentioned common running, when the detected temperatures of ejection temperature sensor is comprising in the set point of temperature scope of above-mentioned target temperature, switch to above-mentioned energy-saving operation.

11. each the described refrigerating plant according in the claim 1～8 is characterized in that:

This refrigerating plant can carry out regulating the turn round common running of above-mentioned compressor of the cooling capacity of cooling heat exchanger while utilizing aforementioned capabilities to regulate parts,

In above-mentioned energy-saving operation, when when following at the appointed time, switching to above-mentioned common running since till the 3rd release one needed time of circulation of first action.

12. each the described refrigerating plant according in the claim 1～8 is characterized in that:

When the accumulation start-stop time of above-mentioned compressor surpasses stipulated number, forbid carrying out above-mentioned energy-saving operation.

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