JPWO2016170680A1 - Refrigeration air conditioner - Google Patents

Abstract

An object of the present invention is to obtain a refrigerating and air-conditioning apparatus capable of completing defrosting in a short time by increasing the defrosting capability of hot gas during hot gas defrosting. The refrigerating and air-conditioning apparatus (100) of the present invention includes an oil separator (2) provided on the discharge side of the compressor (1) and the inlet side of the condenser (3), and the refrigerant flowing out of the oil separator as an evaporator. The hot gas bypass pipe (18) leading to (8), the hot gas adjustment valve (19) provided on the hot gas bypass pipe, and the oil return pipe (13) for returning the lubricating oil stored in the oil separator to the compressor ), An oil cooler (15) provided on the oil return pipe for cooling the refrigeration oil flowing in the oil return pipe, and the oil return pipe from the oil return pipe upstream of the oil cooler in the oil return pipe. An oil supply bypass circuit (85) provided to branch and join with the oil return pipe downstream of the oil cooler in the oil return pipe, and an oil supply bypass electric valve (14 provided on the oil supply bypass circuit) ) And.

Description

  The present invention relates to a refrigeration air conditioner, and more particularly to a refrigeration air conditioner that suppresses an increase in internal temperature during a defrosting operation.

  In general, oil coolers of refrigeration air conditioners are classified into three types: air-cooled, water-cooled, and refrigerant-cooled. Heretofore, there has been a refrigeration apparatus provided with an air-cooled oil cooler (see, for example, Patent Document 1). Conventionally, there has been a refrigerator unit provided with a water-cooled oil cooler (see, for example, Patent Document 2). In the refrigerating apparatus provided with the air-cooled oil cooler described in Patent Document 1, the amount of heat released from the oil cooler to the outside air is reduced as much as possible during hot gas defrosting, and the water-cooled oil described in Patent Document 2 is used. In a refrigerator unit equipped with a cooler, the amount of heat released from the oil cooler to the cooling water is reduced as much as possible during hot gas defrosting to increase the temperature (enthalpy) of the hot gas from the compressor to the evaporator. ing.

JP-A-8-94194 JP-A-9-26215

  However, in the refrigeration apparatus provided with the air-cooled oil cooler described in Patent Document 1, the oil cooler is discharged from the oil cooler to the outside air even at a low outside air temperature state at night or in a cold region even if the rotational speed of the blower is reduced. The amount of heat is not negligible. In the refrigerator unit provided with the water-cooled oil cooler described in Patent Document 2, the flow rate adjustment of the cooling water is within the scope of the local system, and the flow rate of the cooling water is finely adjusted according to the operation state of the refrigerator. The amount of heat released to the cooling water is not negligible. Therefore, in the refrigerating and air-conditioning apparatuses described in Patent Documents 1 and 2, there is a problem that the defrosting ability of hot gas is reduced.

  The present invention has been made against the background of the above-described problems, and during the hot gas defrosting, the refrigeration air-conditioning system that enhances the defrosting ability of the hot gas than before and completes the defrosting in a shorter time than before. The object is to obtain a device.

  A refrigerating air-conditioning apparatus according to the present invention is a refrigerating air-conditioning apparatus having a main circuit in which a compressor, a condenser, a main expansion valve, and an evaporator are connected in order, on the discharge side of the compressor, and An oil separator provided on the inlet side of the condenser and a branch from the main circuit on the inlet side of the condenser so as to merge with the main circuit on the outlet side of the main expansion valve and on the inlet side of the evaporator A hot gas bypass pipe provided to guide the refrigerant flowing out from the oil separator to the evaporator, a hot gas adjustment valve provided on the hot gas bypass pipe, and lubricating oil stored in the oil separator An oil return pipe that returns to the compressor, an oil cooler that is provided on the oil return pipe and that cools the refrigeration machine oil that flows through the oil return pipe, and has an oil flow that is higher than that of the oil cooler in the oil return pipe. The oil return on the upstream side An oil supply bypass circuit provided so as to branch from the pipe and join the oil return pipe downstream of the oil cooler in the oil return pipe, and an oil supply bypass flow rate provided on the oil supply bypass circuit An adjustment means and a control means for controlling the oil supply bypass flow rate adjustment means are provided.

  According to the present invention, during the hot gas defrosting, the oil supply bypass flow rate adjusting means provided on the oil supply bypass circuit is controlled to adjust the oil supply bypass flow rate. For this reason, the temperature (enthalpy) of the hot gas can be increased, and the defrosting time can be shortened.

It is a systematic diagram which shows a refrigerant | coolant system | strain in case the refrigeration air conditioning apparatus 100 which concerns on Embodiment 1 of this invention is an air cooling type. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 1 of this invention. It is a systematic diagram which shows a refrigerant | coolant system | strain in case the refrigeration air conditioning apparatus 100 which concerns on Embodiment 1 of this invention is a water cooling type. It is a systematic diagram which shows a refrigerant | coolant system | strain in case the refrigeration air conditioning apparatus 100 which concerns on Embodiment 2 of this invention is an air cooling type. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 2 of this invention. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 2 of this invention. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 3 of this invention. It is a flowchart which shows the control action of the refrigerating and air-conditioning apparatus 100 which concerns on Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a system diagram showing a refrigerant system when the refrigeration air-conditioning apparatus 100 according to Embodiment 1 of the present invention is of an air cooling type. FIG. 2 is a flowchart showing a control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 1 of the present invention. FIG. 3 is a flowchart showing the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 1 of the present invention. FIG. 4 is a system diagram showing a refrigerant system when the refrigeration air-conditioning apparatus 100 according to Embodiment 1 of the present invention is a water-cooled type.

  As shown in FIG. 1, the refrigeration air conditioner 100 includes a compressor 1, an oil separator 2, a condenser 3, a condenser fan 4, a receiver 5, an intercooler 6, and a main expansion. Valve 7, evaporator 8, evaporator fan 9, intermediate cooling pipe 11, intermediate cooling expansion valve 12, oil return pipe 13, oil supply bypass electric valve 14, oil cooler 15, and motor Cooling pipe 16, motor cooling expansion valve 17, hot gas bypass pipe 18, hot gas adjustment valve 19, discharge temperature detection means 20, oil supply temperature detection means 21, control means 50, and main circuit 80 An oil supply bypass circuit 85.

  The compressor 1, the oil separator 2, the condenser 3, the liquid receiver 5, the intercooler 6, the main expansion valve 7, and the evaporator 8 are sequentially connected by a main circuit 80. . The main expansion valve 7, the evaporator 8, the evaporator fan 9, and the internal temperature detection means 22 are provided in a refrigerated warehouse 23 (freezer warehouse).

  The compressor 1 is a variable capacity compressor that compresses sucked refrigerant and discharges it as high-temperature and high-pressure refrigerant. The oil separator 2 is for separating oil contained in the refrigerant discharged from the compressor 1, and is provided on the discharge side of the compressor 1.

  The condenser 3 is for exchanging heat between the refrigerant separated in the oil separator 2 and the outside air, and is provided on the outlet side of the oil separator 2. The condenser fan 4 is a blowing means for generating an air flow for introducing air into the condenser 3. The liquid receiver 5 is for storing the refrigerant flowing out of the condenser 3, and is provided on the outlet side of the condenser 3.

  The intermediate cooler 6 is a heat exchanger that exchanges heat between the refrigerant flowing out of the liquid receiver 5 and the refrigerant decompressed by the intermediate cooling expansion valve 12, and is provided on the outlet side of the liquid receiver 5. The main expansion valve 7 decompresses and expands the refrigerant flowing out from the intermediate cooler 6 on the main circuit 80, and is provided on the outlet side of the intermediate cooler 6 on the main circuit 80. The evaporator 8 evaporates the refrigerant flowing out of the main expansion valve 7 and is provided on the outlet side of the main expansion valve 7. The evaporator 8 is provided inside the refrigerated warehouse 23. The evaporator fan 9 is a blowing means for generating an air flow for introducing air into the evaporator 8.

  The motor cooling pipe 16 is provided on the outlet side of the intermediate cooler 6 and the inlet side of the main expansion valve 7 in the main circuit 80 so as to connect the main circuit 80 and the motor chamber (not shown) of the compressor 1. Piping. A motor cooling expansion valve 17 is provided on the motor cooling pipe 16. The motor cooling expansion valve 17 expands the refrigerant flowing through the motor cooling pipe 16 under reduced pressure.

  The intermediate cooling pipe 11 is a pipe provided to connect the main circuit 80 and the compressor 1 on the outlet side of the intermediate cooler 6 and on the inlet side of the main expansion valve 7 in the main circuit 80. An intermediate cooler 6 and an intermediate cooling expansion valve 12 are provided on the intermediate cooling pipe 11. The intermediate cooling expansion valve 12 decompresses and expands the refrigerant flowing through the intermediate cooling pipe 11. An intermediate cooler 6 is provided on the outlet side of the intermediate cooling expansion valve 12.

  The oil return pipe 13 is a pipe for returning from the bottom of the oil separator 2 to the compressor 1 via the oil cooler 15. The oil cooler 15 cools refrigeration oil flowing in the oil return pipe 13 and is provided on the oil return pipe 13.

  The oil supply bypass circuit 85 is a circuit for bypassing at least part of the cooler oil separated in the oil separator 2 and returning it to the compressor 1 by bypassing the oil cooler 15. The oil supply bypass circuit 85 branches from the oil return pipe 13 on the upstream side of the oil flow from the oil cooler 15 in the oil return pipe 13, and on the downstream side of the oil flow from the oil cooler 15 in the oil return pipe 13. It is provided so as to merge with the oil return pipe 13.

  The oil supply bypass electric valve 14 is an electric valve that adjusts the amount of lubricating oil flowing through the oil supply bypass circuit 85, and is provided on the oil supply bypass circuit 85. The oil supply bypass electric valve 14 is configured to be able to linearly adjust the bypass amount of the lubricating oil.

  The hot gas bypass pipe 18 is a pipe for guiding at least a part of the refrigerant from which the oil has been separated in the oil separator 2 to the evaporator 8 without passing through the condenser 3 or the like. The hot gas bypass pipe 18 is provided so as to branch from the main circuit 80 on the inlet side of the condenser 3 and merge with the main circuit 80 on the outlet side of the main expansion valve 7 and on the inlet side of the evaporator 8. The hot gas adjustment valve 19 adjusts the amount of refrigerant flowing on the hot gas bypass pipe 18 and is provided on the hot gas bypass pipe 18.

  The discharge temperature detection unit 20 is a temperature detection unit that detects the temperature of the refrigerant discharged from the compressor 1. The discharge temperature detection means 20 is provided on the discharge side of the compressor 1 and on the inlet side of the oil separator 2. The oil supply temperature detection means 21 is a temperature detection means for detecting the temperature of the refrigerating machine oil supplied to the compressor 1. The oil supply temperature detecting means 21 is provided on the oil return pipe 13 and on the suction side of the compressor 1 with respect to the portion where the oil return pipe 13 and the oil supply bypass circuit 85 are connected.

  The control means 50 controls various sensors and various expansion valves. The control means 50 is configured by, for example, hardware such as a circuit device that realizes this function, or software executed on an arithmetic device such as a microcomputer or a CPU. The control means 50 compares the set temperature (target internal temperature) set in advance by a person with the detected temperature (internal temperature) of the internal temperature detecting means 22, and the detected temperature of the internal temperature detecting means 22 is detected. If the temperature is higher than the set temperature (thermo ON temperature) or higher, the refrigeration air conditioner 100 is started (operated), and if the temperature detected by the internal temperature detection means 22 is equal to or lower than the set temperature (thermo OFF temperature). Then, control for stopping the refrigeration air conditioner 100 is performed. Such control of the refrigerating and air-conditioning apparatus 100 is not limited to the example performed by the control unit 50, and may be performed by a control unit provided separately from the control unit 50.

  In the first embodiment, an example will be described in which the oil supply bypass motor-operated valve 14 is adopted as the oil supply bypass flow rate adjusting means and the discharge temperature detection means 20 is adopted as the temperature detection means.

  Hereinafter, a normal refrigerant cycle of the refrigeration air-conditioning apparatus 100 according to Embodiment 1 will be described. Here, the normal time indicates a state in which the hot gas regulating valve 19 is controlled to be fully closed and the hot gas bypass amount is not present. That is, the normal time refers to a state in which all the refrigerant gas separated by the oil separator 2 flows into the condenser 3 without flowing through the hot gas bypass pipe 18.

  First, the refrigerant sucked into the compressor 1 is compressed to a high temperature and high pressure state inside the compressor 1. The refrigerant discharged from the compressor 1 is separated into refrigerant gas and refrigerating machine oil in the oil separator 2.

  The refrigerant gas separated by the oil separator 2 flows into the condenser 3 and is condensed by exchanging heat with the outside air and dissipating heat, and flows out as a refrigerant liquid. The refrigerant liquid flowing out from the condenser 3 flows into the liquid receiver 5. The refrigerant flowing out from the liquid receiver 5 is supplied to the intercooler 6. The intermediate cooler 6 exchanges heat with a relatively low-temperature refrigerant two-phase flow that flows through the intermediate cooling pipe 11 and is cooled to a supercooled state.

  Of the refrigerant flowing out from the intercooler 6, the refrigerant flowing through the main circuit 80 is decompressed and expanded in the main expansion valve 7 and then flows into the evaporator 8. The refrigerant that has flowed into the evaporator 8 evaporates by exchanging heat with the internal air that is the material to be cooled and absorbs heat, and is sucked into the compressor 1 as superheated gas.

  A part of the refrigerant flowing out of the intercooler 6 and flowing through the motor cooling pipe 16 flows through the motor cooling expansion valve 17 and is decompressed and expanded to form a relatively low temperature two-phase flow. Supplied to the chamber to cool the motor windings.

  A part of the refrigerant flowing out of the intermediate cooler 6 flows through the intermediate cooling pipe 11 and flows through the intermediate cooling expansion valve 12 and is decompressed and expanded. The refrigerant expanded under reduced pressure in the intermediate cooling expansion valve 12 exchanges heat with the refrigerant flowing out of the liquid receiver 5 in the intermediate cooler 6 and is supplied to the compressor 1.

  The refrigerating machine oil separated by the oil separator 2 is cooled by exchanging heat with the outside air in the oil cooler 15 through the oil return pipe 13. The refrigerating machine oil cooled by heat exchange in the oil cooler 15 is returned to the compressor 1.

  Below, the refrigerant cycle at the time of hot gas defrosting of the refrigerating and air-conditioning apparatus 100 according to Embodiment 1 will be described. At the time of hot gas defrosting, unlike the normal time, the hot gas regulating valve 19 is controlled to a desired opening degree (except for the closed state). Therefore, at least a part of the refrigerant gas separated by the oil separator 2 flows into the evaporator 8 from the outlet side of the main expansion valve 7 and from the inlet side of the evaporator 8 through the hot gas bypass pipe 18. . The refrigerant supplied to the evaporator 8 dissipates heat in the evaporator 8 to melt frost that has grown on the surface of the cooler. The refrigerant gas flowing out of the evaporator 8 is supplied to the compressor 1.

  Next, the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 1 will be described with reference to FIG. In the first embodiment, when the defrosting operation is started, the control unit 50 controls the opening degree of the fuel supply bypass electric valve 14 based on the discharge temperature detected by the discharge temperature detection unit 20 to increase the oil supply temperature as much as possible. It operates to increase the defrosting ability of hot gas by maintaining. The control means 50 automatically performs each determination and control output in the flowchart of FIG.

  In step S11, the control means 50 starts the defrosting operation simultaneously with the establishment of the defrosting start condition, and proceeds to step S12. In step S12, the control means 50 starts the compressor 1, turns on (opens) the hot gas regulating valve 19 and turns off (closes) the fuel supply bypass electric valve 14, and proceeds to step S13.

In step S13, the control means 50 determines whether or not the defrost termination condition is satisfied.
In step S13, when it is determined that the defrost termination condition is satisfied (Yes in step S13), the control unit 50 proceeds to step S19.
On the other hand, when it is determined in step S13 that the defrosting termination condition is not satisfied (No in step S13), the control unit 50 proceeds to step S14.

In step S14, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or higher than the discharge temperature second threshold value. The discharge temperature second threshold is a threshold set in the control means 50.
In step S14, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or higher than the discharge temperature second threshold (Yes in step S14), the control unit 50 proceeds to step S16.
On the other hand, when it is determined in step S14 that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or higher than the discharge temperature second threshold (No in step S14), the control unit 50 proceeds to step S15.

In step S15, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or lower than the discharge temperature first threshold value. The discharge temperature first threshold is a threshold set in the control means 50.
In step S15, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or lower than the discharge temperature first threshold value (Yes in step S15), the control unit 50 proceeds to step S18.
On the other hand, in step S15, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or lower than the discharge temperature first threshold value (No in step S15), the control unit 50 proceeds to step S17.

In step S16, the control means 50 reduces the opening degree of the fuel supply bypass electric valve 14, and proceeds to step S13.
In step S17, the control means 50 holds the fuel supply bypass electric valve 14 (maintains the current opening), and proceeds to step S13.
In step S18, the control means 50 increases the opening degree of the fuel supply bypass electric valve 14, and proceeds to step S13.

  In step S19, the control means 50 closes the hot gas regulating valve 19 and the fuel supply bypass electric valve 14 and stops the compressor 1 in order to end the defrosting operation, and proceeds to step S20. In step S20, the control means 50 ends the defrosting operation.

  Note that the discharge temperature first threshold value and the discharge temperature second threshold value described above need to be set in consideration of the discharge temperature limit (for example, 100 ° C.) of the compressor 1. Specifically, it is a value satisfying the relationship of discharge temperature limit> second threshold> first threshold. For example, the discharge temperature second threshold is 90 ° C., and the discharge temperature first threshold is 70 ° C.

As described above, the refrigerating and air-conditioning apparatus 100 according to Embodiment 1 includes the main circuit 80 in which the compressor 1, the condenser 3, the main expansion valve 7, and the evaporator 8 are sequentially connected. An oil separator 2 provided on the discharge side of the compressor 1 and on the inlet side of the condenser 3; and on the outlet side of the main expansion valve 7 branched from the main circuit 80 on the inlet side of the condenser 3. In addition, a hot gas bypass pipe 18 that is provided so as to merge with the main circuit 80 on the inlet side of the evaporator 8 and guides the refrigerant flowing out from the oil separator 2 to the evaporator 8 and a hot gas provided on the hot gas bypass pipe 18. Oil for cooling the refrigerating machine oil provided on the gas return valve 13, the oil return pipe 13 for returning the lubricating oil stored in the oil separator 2 to the compressor 1, and the oil return pipe 13. Oil cooling of the cooler 15 and the oil return pipe 13 The oil supply bypass circuit is provided so as to branch from the oil return pipe 13 on the upstream side of the oil flow from the condenser 15 and to merge with the oil return pipe 13 on the downstream side of the oil cooler 15 in the oil return pipe 13. 85, an oil supply bypass electric valve 14 provided on the oil supply bypass circuit 85, and a control means 50 for controlling the oil supply bypass electric valve 14.
For this reason, oil supply temperature can be maintained as high as possible during hot gas defrosting, and thereby the temperature (enthalpy) of hot gas can be increased. Therefore, hot gas with high defrosting capability can be generated stably. Moreover, defrosting time can be shortened by increasing the defrosting capability of hot gas, and an increase in the internal temperature during defrosting (a period during which cooling is not performed) can be suppressed.

  Further, it is provided with a discharge temperature detecting means 20 for detecting the temperature of the refrigerant discharged from the compressor 1 and used for controlling the fuel supply bypass electric valve 14, and the control means 50 is provided when the hot gas regulating valve 19 is opened. The oil supply bypass electric valve 14 is controlled based on the value of the discharge temperature detecting means 20. For this reason, the effect mentioned above of this Embodiment 1 can be produced.

  In the above description, the discharge temperature detecting means 20 is adopted as the temperature detecting means. Instead, the oil supply temperature detecting means 21 may be adopted as the temperature detecting means. A flowchart in this case is shown in FIG. Steps S21 and S22 in FIG. 3 are different from steps S14 and S15 in FIG.

In step S21, the control means 50 determines whether or not the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or higher than the oil supply temperature second threshold.
In Step S21, when it is determined that the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or higher than the oil supply temperature second threshold (Yes in Step S21), the control means 50 proceeds to Step S16.
On the other hand, in step S21, when it is determined that the fueling temperature detected by the fueling temperature detection unit 21 is not equal to or higher than the fueling temperature second threshold (No in step S21), the control unit 50 proceeds to step S22.

In step S22, the control means 50 determines whether or not the oil supply temperature detected by the oil supply temperature detecting means 21 is equal to or lower than the oil supply temperature first threshold value.
In step S22, when it is determined that the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or lower than the oil supply temperature first threshold value (Yes in step S22), the control means 50 proceeds to step S18.
On the other hand, in step S22, when it is determined that the fueling temperature detected by the fueling temperature detection unit 21 is not equal to or lower than the fueling temperature first threshold value (No in step S22), the control unit 50 proceeds to step S17.

  In addition, the above-mentioned oil supply temperature first threshold value and oil supply temperature second threshold value must be set in consideration of the oil supply temperature limit of the compressor. That is, it is necessary to set a value such that the upper limit of the oil supply temperature> the second threshold value of the oil supply temperature> the first threshold value of the oil supply temperature> the lower limit of the oil supply temperature. Specifically, when the upper limit of the oil supply temperature is 60 ° C. and the lower limit of the oil supply temperature is 20 ° C., the second oil supply temperature threshold is 50 ° C., and the first oil supply temperature threshold is 30 ° C.

  Further, the control unit 50 includes an oil supply temperature detecting means 21 that is used for controlling the oil supply bypass electric valve 14 and detects the temperature of the lubricating oil supplied to the compressor 1, and the control means 50 is provided when the hot gas adjusting valve 19 is opened. In addition, the oil supply bypass electric valve 14 is controlled based on the value of the oil supply temperature detecting means 21. For this reason, the effect mentioned above of this Embodiment 1 can be produced.

  Further, the oil supply bypass electric valve 14 controls the oil supply bypass electric valve 14 so as to increase the amount of lubricating oil flowing through the oil supply bypass circuit 85 when the detected temperature of the discharge temperature detecting means 20 is equal to or lower than the first threshold value. When the temperature detected by the temperature detection means 20 is equal to or higher than a second threshold value that is greater than the first threshold value, the fuel supply bypass electric valve 14 is controlled so as to reduce the amount of lubricating oil flowing through the fuel supply bypass circuit 85. For this reason, the effect of this Embodiment 1 mentioned above can be show | played.

  In the above description, the air-cooled refrigerating and air-conditioning apparatus has been described as an example. A system diagram in this case is shown in FIG.

  Since the refrigeration air conditioner 100 in FIG. 1 is air-cooled, the condenser 3, the condenser fan 4, and the oil cooler 15 are adopted. However, since the refrigeration air-conditioner 100 in FIG. 4 is water-cooled, the water-cooled condenser is used. 30, a condenser cooling water pipe 31, a water cooling oil cooler 32, and an oil cooling cooling water pipe 33 are employed.

  The water-cooled condenser 30 is for exchanging heat between the refrigerant separated in the oil separator 2 and water, and is provided on the outlet side of the oil separator 2. The condenser cooling water pipe 31 is a pipe through which water exchanged with the refrigerant supplied to the water-cooled condenser 30 passes. The water-cooled oil cooler 32 is a heat exchanger that cools refrigeration oil flowing in the oil return pipe 13, and is provided on the oil return pipe 13. The oil cooling cooling water pipe 33 is a pipe through which water that exchanges heat with the refrigerant flowing in the water cooling oil cooler 32 is passed.

Embodiment 2. FIG.
In the second embodiment, unlike the first embodiment, a fuel supply bypass solenoid valve 24 is employed as a fuel supply bypass flow rate adjusting means. In the second embodiment, the configuration is almost the same as that shown in the first embodiment. The same reference numerals are given to the same devices, and descriptions of the same devices are omitted.

  FIG. 5 is a system diagram showing a refrigerant system when the refrigeration air-conditioning apparatus 100 according to Embodiment 2 of the present invention is an air-cooled type. FIG. 6 is a flowchart showing the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 2 of the present invention. FIG. 7 is a flowchart showing the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 2 of the present invention.

  As shown in FIG. 5, an oil supply bypass electromagnetic valve 24 is provided instead of the oil supply bypass electric valve 14 in FIG. 1. The oil supply bypass electromagnetic valve 24 is an electromagnetic valve that adjusts the amount of refrigerant flowing through the oil supply bypass circuit 85, and is provided on the oil supply bypass circuit 85. The oil supply bypass solenoid valve 24 is configured to be switchable between a closed state and an open state.

  Below, control operation | movement of the refrigerating and air-conditioning apparatus 100 which concerns on this Embodiment 2 is demonstrated using FIG. In the second embodiment, when the control means 50 starts the defrosting operation, the open / close state of the oil supply bypass solenoid valve 24 is controlled based on the discharge temperature detected by the discharge temperature detection means 20, and the oil supply temperature is increased as much as possible. Take action to maintain the hot gas defrosting capacity by maintaining. In FIG. 6, the same processes as those in FIGS. 2 and 3 are denoted by the same reference numerals.

  In step S11, the control means 50 starts the defrosting operation simultaneously with the establishment of the defrosting start condition, and proceeds to step S31. In step S31, the control means 50 starts the compressor, turns on (opens) the hot gas regulating valve 19 and turns off (closes) the oil supply bypass solenoid valve 24, and proceeds to step S13.

In step S13, the control means 50 determines whether or not the defrost termination condition is satisfied.
In step S13, when it is determined that the defrost termination condition is satisfied (Yes in step S13), the control unit 50 proceeds to step S35.
On the other hand, when it is determined in step S13 that the defrosting termination condition is not satisfied (No in step S13), the control unit 50 proceeds to step S14.

In step S14, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or higher than the discharge temperature second threshold value. The discharge temperature second threshold is a threshold set in the control means 50.
In step S14, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or higher than the discharge temperature second threshold (Yes in step S14), the control unit 50 proceeds to step S32.
On the other hand, when it is determined in step S14 that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or higher than the discharge temperature second threshold (No in step S14), the control unit 50 proceeds to step S15.

In step S15, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or lower than the discharge temperature first threshold value. The discharge temperature first threshold is a threshold set in the control means 50.
In step S15, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or lower than the discharge temperature first threshold value (Yes in step S15), the control unit 50 proceeds to step S34.
On the other hand, when it is determined in step S15 that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or lower than the discharge temperature first threshold (No in step S15), the control unit 50 proceeds to step S33.

In step S32, the control means 50 turns off the fuel supply bypass solenoid valve 24 (closed state), and proceeds to step S13.
In step S33, the control means 50 holds the fuel supply bypass solenoid valve 24 (maintains the current open / close state), and proceeds to step S13.
On the other hand, in step S34, the control means 50 turns on (opens) the fuel supply bypass solenoid valve 24, and proceeds to step S13.

  In step S35, the control means 50 closes the hot gas regulating valve 19 and closes the fuel supply bypass solenoid valve 24 in order to end the defrosting operation. The control means 50 stops the compressor 1. In step S20, the defrosting operation ends.

  Note that the discharge temperature first threshold value and the discharge temperature second threshold value described above must be set in consideration of the discharge temperature limit (for example, 100 ° C.) of the compressor 1. Specifically, the value satisfies the relationship of discharge temperature limit> second threshold> first threshold. For example, the discharge temperature second threshold is 90 ° C., and the discharge temperature first threshold is 70 ° C.

As described above, in the refrigerating and air-conditioning apparatus 100 according to the second embodiment, during the hot gas defrosting, the control means 50 opens and closes the fuel supply bypass electromagnetic valve 24 based on the discharge temperature detected by the discharge temperature detection means 20. It is to adjust the state.
For this reason, the refueling temperature can be maintained as high as possible during the hot gas defrosting, and thereby the hot gas temperature (enthalpy) can be increased, and thus a hot gas having a high defrosting capacity can be stably generated. It becomes. Moreover, defrosting time of hot gas can be increased, so that the defrosting time can be shortened, and an increase in the internal temperature during defrosting (non-cooled period) can be suppressed.

  In the above description, the discharge temperature detecting means 20 is adopted as the temperature detecting means. Instead, the oil supply temperature detecting means 21 may be adopted as the temperature detecting means. FIG. 7 shows a flowchart when the oil supply temperature detecting means 21 is employed as the temperature detecting means. Steps S21 and S22 in FIG. 7 are different from steps S14 and S15 in FIG.

In step S21, the control means 50 determines whether or not the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or higher than the oil supply temperature second threshold.
In step S21, if the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or higher than the oil supply temperature second threshold (Yes in step S21), the control means 50 proceeds to step S32.
On the other hand, in step S21, if the oil supply temperature detected by the oil supply temperature detection means 21 is not equal to or higher than the oil supply temperature second threshold (No in step S21), the control means 50 proceeds to step S22.

In step S22, the control means 50 determines whether or not the oil supply temperature detected by the oil supply temperature detecting means 21 is equal to or lower than the oil supply temperature first threshold value.
In step S22, when the control means 50 determines that the oil supply temperature detected by the oil supply temperature detection means 21 is equal to or lower than the oil supply temperature first threshold value (Yes in step S22), the control means 50 proceeds to step S34.
On the other hand, if the control means 50 determines in step S22 that the oil supply temperature detected by the oil supply temperature detecting means 21 is not equal to or lower than the oil supply temperature first threshold value (No in step S22), the control means 50 proceeds to step S33.

  In addition, the oil supply temperature first threshold value and the oil supply temperature second threshold value described above are set in consideration of the oil supply temperature limit of the compressor. That is, it is necessary to set a value such that the upper limit of the oil supply temperature> the second threshold value of the oil supply temperature> the first threshold value of the oil supply temperature> the lower limit of the oil supply temperature. Specifically, for example, when the upper limit of the oil supply temperature is 60 ° C. and the lower limit of the oil supply temperature is 20 ° C., the second oil supply temperature threshold is 50 ° C., and the first oil supply temperature threshold is 30 ° C.

  In the second embodiment, the air-cooled refrigeration air conditioner has been described as an example. However, the present invention is not limited to this. For example, the present invention can be similarly applied to a water-cooled refrigeration air conditioner.

Embodiment 3 FIG.
In the third embodiment, unlike the second embodiment, when the fuel supply bypass solenoid valve 24 is changed from the closed state to the open state, the fuel supply bypass solenoid valve 24 is changed to the open state after switching between opening and closing a plurality of times. And make transitions. In the third embodiment, items that are not particularly described are the same as those in the second embodiment, and the same functions and configurations are described using the same reference numerals.

  FIG. 8 is a flowchart showing the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 3 of the present invention. FIG. 9 is a flowchart showing the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 3 of the present invention. First, the processing of FIG. 8 will be described.

  In general, the compressor 1 includes a compression mechanism (not shown) that compresses the refrigerant gas, and a casing (not shown) that covers the compression mechanism. Here, in a high-performance compressor, in order to improve the compressor performance, the gap formed between the compression mechanism and the casing is narrowed as much as possible, and a sudden temperature change, particularly a sudden heating. Especially weak. That is, since the compression mechanism expands when it is suddenly heated, there is a possibility that there will be no gap with the casing and contact will occur and seizure will occur. Here, in Embodiment 2, since the oil supply bypass solenoid valve 24 is employed as the oil supply bypass flow rate adjusting means, a sudden temperature change is likely to occur. That is, when the oil supply bypass solenoid valve 24 is in the OFF (closed) state, relatively low-temperature refrigerating machine oil cooled in the oil cooler 15 is supplied to the compressor 1, but the oil supply bypass solenoid valve 24 is When switching from OFF (closed) to ON (open), the refrigerating machine oil separated in the oil separator 2 bypasses the oil cooler 15 and is supplied to the compressor 1. That is, the refrigerating machine oil that is not cooled in the oil cooler 15 among the refrigerating machine oil separated in the oil separator 2 is suddenly supplied to the compressor 1. Therefore, rapid heating is likely to occur. In particular, as described above, when the compressor 1 is composed of a high-performance compressor that narrows the gap formed between the compression mechanism and the casing as much as possible, this problem becomes significant.

  In the third embodiment, in order to suppress the rapid heating described above, when the oil supply bypass solenoid valve 24 is turned off (closed) and the oil supply bypass solenoid valve 24 is turned on (open), the open / close state is changed. Then, a control operation is performed to make the transition to the open state after opening and closing several times.

  Details of the control operation of the refrigerating and air-conditioning apparatus 100 according to Embodiment 3 will be described based on the flowcharts of FIGS. In the description of the flowcharts of FIGS. 8 and 9, the same processes as those in FIGS. 2 and 6 are denoted by the same reference numerals. Hereinafter, FIG. 8 will be described first.

  In step S11, the control means 50 starts the defrosting operation simultaneously with the establishment of the defrosting start condition, and proceeds to step S31. In step S31, the control means 50 starts the compressor 1, turns on (opens) the hot gas regulating valve 19, and turns off (closes) the oil supply bypass solenoid valve 24, and proceeds to step S13.

In step S13, the control means 50 determines whether or not the defrost termination condition is satisfied.
In step S13, when it is determined that the defrost termination condition is satisfied (Yes in step S13), the control unit 50 proceeds to step S35.
On the other hand, when it is determined in step S13 that the defrosting termination condition is not satisfied (No in step S13), the control unit 50 proceeds to step S14.

In step S14, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or higher than the discharge temperature second threshold value. The discharge temperature second threshold is a threshold set in the control means 50.
In step S14, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or higher than the discharge temperature second threshold (Yes in step S14), the control unit 50 proceeds to step S32.
On the other hand, when it is determined in step S14 that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or higher than the discharge temperature second threshold (No in step S14), the control unit 50 proceeds to step S15.

In step S15, the control means 50 determines whether or not the discharge temperature detected by the discharge temperature detection means 20 is equal to or lower than the discharge temperature first threshold value. The discharge temperature first threshold is a threshold set in the control means 50.
In step S15, when it is determined that the discharge temperature detected by the discharge temperature detection unit 20 is equal to or lower than the discharge temperature first threshold value (Yes in step S15), the control unit 50 proceeds to step S41.
On the other hand, when it is determined in step S15 that the discharge temperature detected by the discharge temperature detection unit 20 is not equal to or lower than the discharge temperature second threshold (No in step S15), the control unit 50 proceeds to step S33.

In step S41, the control means 50 determines whether or not the current refueling bypass solenoid valve 24 is in a closed state.
In step S41, when it is determined that the current open / close state of the fuel supply bypass solenoid valve 24 is the closed state (Yes in step S41), the control unit 50 proceeds to step S42.
On the other hand, when it is determined in step S41 that the current open / close state of the fuel supply bypass solenoid valve 24 is not closed (No in step S41), the control unit 50 proceeds to step S34.

In step S32, the control means 50 turns OFF the fuel supply bypass solenoid valve 24 (closed state), and proceeds to step S13.
In step S33, the control means 50 holds the fuel supply bypass solenoid valve 24 (maintains the current open / close state), and proceeds to step S13.
In step S34, the control means 50 turns ON the fuel supply bypass solenoid valve 24 (open state), and proceeds to step S13.
In step S42, the control means 50 performs a transition process and proceeds to step S13. The process of step S42 will be described with reference to FIG.

  In step S35, the control means 50 closes the hot gas regulating valve 19 and closes the fuel supply bypass solenoid valve 24 in order to end the defrosting operation. The control means 50 stops the compressor 1 and ends the defrosting operation (step S20).

  Next, the transition process in step S42 in FIG. 8 will be described with reference to FIG. The transition process is a process for opening and closing the fuel supply bypass solenoid valve 24 a plurality of times when the fuel supply bypass solenoid valve 24 is transitioned from the closed state to the open state.

  In step S51, the control means 50 starts a transition process and proceeds to step S52. In step S52, the control means 50 resets the counter C (zero), and proceeds to step S53. In step S53, after resetting the timer t1, the control unit 50 starts (starts counting), turns on (opens) the fuel supply bypass solenoid valve 24, and proceeds to step S54. In step S54, the control means 50 adds 1 to the counter C, and proceeds to step S55.

In step S55, the control means 50 determines whether or not the value of the counter C is greater than or equal to the counter threshold value.
In step S55, when it is determined that the value of the counter C is equal to or greater than the counter threshold value (Yes in step S55), the control unit 50 proceeds to step S59.
On the other hand, when it is determined in step S55 that the value of the counter C is not equal to or greater than the counter threshold value (No in step S55), the control unit 50 proceeds to step S56.

In step S56, the control means 50 determines whether or not the value of the timer t1 is greater than or equal to the timer threshold value.
In step S56, when it is determined that the value of the timer t1 is equal to or greater than the timer threshold value (Yes in step S56), the control unit 50 proceeds to step S57. In step S57, after resetting the timer t2, the control means 50 starts (starts counting), turns off the fuel supply bypass solenoid valve 24 (closes), and proceeds to step S58.
On the other hand, if it is determined in step S56 that the value of the timer t1 is not equal to or greater than the timer threshold (No in step S56), the control unit 50 repeats the determination in step S56.

In step S58, the control means 50 determines whether or not the value of the timer t2 is greater than or equal to the timer threshold value.
In step S58, when it is determined that the value of the timer t2 is equal to or greater than the timer threshold value (Yes in step S58), the control unit 50 proceeds to step S53.
On the other hand, when determining in step S58 that the value of the timer t2 is not equal to or greater than the timer threshold value (No in step S58), the control unit 50 repeats the determination in step S58.

  In step S59, the control means 50 ends the transition process. At this time, the fuel supply bypass solenoid valve 24 is opened.

  The timer threshold value and the counter threshold value described above are set so as not to be heated suddenly when refrigerating machine oil is returned to the compressor 1. Specifically, for example, 3 seconds is set as the timer threshold, and 4 times is set as the counter threshold.

As described above, when the control unit 50 controls the fuel supply bypass electromagnetic valve 24 from the closed state to the open state when the hot gas regulating valve 19 is opened, After the fuel supply bypass solenoid valve 24 is opened and closed a plurality of times, the fuel supply bypass solenoid valve 24 is opened.
For this reason, even in a refrigeration air conditioner equipped with a high-performance type compressor 1, the oil supply temperature can be maintained as high as possible during hot gas defrosting without causing compressor seizure, and thus hot having high defrosting capability. Gas can be generated stably. Further, the defrosting ability of the hot gas is increased, so that the defrosting time can be shortened and an increase in the internal temperature during the defrosting (non-cooled period) can be suppressed.

  Thereby, when opening and closing the oil supply bypass solenoid valve 24 a plurality of times, the refrigerating machine oil cooled in the oil return pipe 13 and the refrigerating machine oil not cooled are mixed, and the influence of the heat capacity of the oil return pipe 13 By receiving, it becomes possible to raise the temperature of the refrigerating machine oil returned to the compressor 1 gently.

  That is, rapid heating can be prevented, and the technology of the present invention can be applied to a refrigeration air conditioner equipped with a high-performance type compressor.

  In the above description, the discharge temperature detecting means 20 is adopted as the temperature detecting means. Instead, the oil supply temperature detecting means 21 may be adopted as the temperature detecting means. Further, the present invention can be similarly applied to a water-cooled refrigeration air conditioner.

  The oil supply bypass electric valve 14 corresponds to the electric valve of the present invention, and the oil supply bypass electromagnetic valve 24 corresponds to the electromagnetic valve of the present invention.

1 compressor, 2 oil separator, 3 condenser, 4 condenser fan, 5 receiver, 6 intermediate cooler, 7 main expansion valve, 8 evaporator, 9 evaporator fan, 11 intermediate cooling pipe, 12 intermediate Expansion valve for cooling, 13 Oil return pipe, 14 Oil supply bypass motor operated valve, 15 Oil cooler, 16
Motor cooling piping, 17 Motor cooling expansion valve, 18 Hot gas bypass piping, 19 Hot gas adjustment valve, 20 Discharge temperature detection means, 21 Oil supply temperature detection means, 22 Inside temperature detection means, 23 Cold storage warehouse, 24 Oil supply bypass electromagnetic Valve, 30 Water-cooled condenser, 31 Cooling water pipe for condenser, 32 Water-cooled oil cooler, 33 Cooling water pipe for oil cooling, 50 Control means, 80 Main circuit, 85 Oil supply bypass circuit, 100 Refrigeration air conditioner.

A refrigerating air-conditioning apparatus according to the present invention is a refrigerating air-conditioning apparatus having a main circuit in which a compressor, a condenser, a main expansion valve, and an evaporator are connected in order, on the discharge side of the compressor, and An oil separator provided on the inlet side of the condenser and a branch from the main circuit on the inlet side of the condenser so as to merge with the main circuit on the outlet side of the main expansion valve and on the inlet side of the evaporator A hot gas bypass pipe provided to guide the refrigerant flowing out from the oil separator to the evaporator, a hot gas adjustment valve provided on the hot gas bypass pipe, and lubricating oil stored in the oil separator An oil return pipe that returns to the compressor, an oil cooler that is provided on the oil return pipe and that cools the refrigeration machine oil that flows through the oil return pipe, and has an oil flow that is higher than that of the oil cooler in the oil return pipe. The oil return on the upstream side An oil supply bypass circuit provided so as to branch from the pipe and join the oil return pipe downstream of the oil cooler in the oil return pipe, and an oil supply bypass flow rate provided on the oil supply bypass circuit Adjustment means, control means for controlling the oil supply bypass flow rate adjustment means, and temperature detection means used for controlling the oil supply bypass flow rate adjustment means, wherein the temperature detection means is a refrigerant discharged from the compressor Or the temperature of the lubricating oil supplied to the compressor, and when the temperature detected by the temperature detecting means is equal to or lower than a first threshold value, the oil supply bypass flow rate adjusting means performs lubrication flowing through the oil supply bypass circuit. The oil supply bypass flow rate adjusting means is controlled to increase the amount of oil, and the temperature detected by the temperature detecting means is greater than or equal to a second threshold value greater than the first threshold value. And it controls the fuel supply bypass flow rate adjustment means to reduce the amount of lubricating oil flowing in the oil supply bypass circuit.

Claims (7)

A refrigeration air conditioner having a main circuit in which a compressor, a condenser, a main expansion valve, and an evaporator are sequentially connected,
An oil separator provided on the discharge side of the compressor and on the inlet side of the condenser;
The refrigerant branched from the main circuit on the inlet side of the condenser and provided to join the main circuit on the outlet side of the main expansion valve and on the inlet side of the evaporator, and the refrigerant flowing out from the oil separator is Hot gas bypass piping leading to the evaporator,
A hot gas regulating valve provided on the hot gas bypass pipe;
An oil return pipe for returning the lubricating oil stored in the oil separator to the compressor;
An oil cooler that is provided on the oil return pipe and cools refrigeration oil flowing in the oil return pipe;
The oil return pipe branches off from the oil return pipe at an upstream side of the oil flow from the oil cooler, and the oil return pipe joins the oil return pipe at a downstream side of the oil cooler from the oil cooler. An oil supply bypass circuit provided to
Oil supply bypass flow rate adjusting means provided on the oil supply bypass circuit;
A refrigerating and air-conditioning apparatus comprising: control means for controlling the oil supply bypass flow rate adjusting means. A temperature detecting means used for controlling the oil supply bypass flow rate adjusting means;
The temperature detecting means includes
Discharge temperature detection means for detecting the temperature of the refrigerant discharged from the compressor;
The control means includes
The refrigerating and air-conditioning apparatus according to claim 1, wherein the refueling bypass flow rate adjusting means is controlled based on a value of the discharge temperature detecting means when the hot gas adjusting valve is opened. A temperature detecting means used for controlling the oil supply bypass flow rate adjusting means;
The temperature detecting means includes
Oil supply temperature detection means for detecting the temperature of the lubricating oil supplied to the compressor;
The control means includes
The refrigerating and air-conditioning apparatus according to claim 1, wherein when the hot gas adjustment valve is opened, the oil supply bypass flow rate adjusting means is controlled based on a value of the oil supply temperature detecting means. The oil supply bypass flow rate adjusting means is
When the temperature detected by the temperature detecting means is equal to or lower than a first threshold, the oil supply bypass flow rate adjusting means is controlled to increase the amount of lubricating oil flowing through the oil supply bypass circuit;
The oil supply bypass flow rate adjusting means is controlled so as to reduce the amount of lubricating oil flowing through the oil supply bypass circuit when the temperature detected by the temperature detection means is equal to or greater than a second threshold value that is greater than the first threshold value. The refrigerating and air-conditioning apparatus according to claim 3. The oil supply bypass flow rate adjusting means is
It is a motor operated valve. The refrigerating and air-conditioning apparatus according to any one of claims 1 to 4. The oil supply bypass flow rate adjusting means is
It is a solenoid valve. The refrigeration air conditioner as described in any one of Claims 1-4. The control means includes
The said solenoid valve is made into an open state, after opening and closing the said solenoid valve in multiple times, when controlling the said solenoid valve from a closed state to an open state when the said hot gas regulating valve is open | released. Refrigeration air conditioner.

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