Refrigeration method and system for controlling two temperatures through single compressor

Abstract

The invention relates to the technical field of compressor temperature control, in particular to a refrigeration method and system for controlling two temperatures through a single compressor, and the method can be applied to a double-temperature control system, that is, two-way temperature output and control can be achieved by adopting one compressor unit or liquid cooling machine. When the device is used for testing, two products with different testing requirements can be tested at the same time, and the device manufactured according to the principle of the method is small in overall size, low in power and low in failure rate; the double evaporators are of a plate heat exchange design, the refrigerating capacity is adjusted by an independent PID controller, a one-way valve is designed and installed on an air return pipe, and the situation that refrigerants flow back to the plate heat exchanger of the low-temperature evaporator due to negative pressure when the low-temperature working condition is operated is avoided, and when different temperatures are controlled, the return air temperature is high while the return air temperature is low, and the refrigerants are mixed at the front end of the gas-liquid separator firstly; the cold bypass branch and the hot bypass branch are subjected to compensation adjustment according to the state of the compressor, the air inlet temperature of about 10 DEG C is achieved, the problem of air return deviation during operation at different temperatures is effectively solved through the design, and the optimal operation state of the compressor can be guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of compressor temperature control, and specifically provides a refrigeration method and system for controlling two temperatures with a single compressor. Background Art

[0002] For equipment with temperature control requirements such as the water-cooled heat dissipation of motors, motor controllers, and important chips, a single-compressor refrigeration system, a single evaporator, and a single water pump are usually adopted, and the supply liquid temperature is a unified temperature. When multiple paths need to be temperature-controlled, the supply liquid circuit realizes multi-path liquid supply through a manifold. Although such a compressor refrigeration device has a small volume and the required flow rate of each path can be achieved by adjusting the valve, the same supply liquid temperature cannot meet the different temperature requirements of each path.

[0003] In order to meet the requirements of multiple paths for different temperatures, that is, to independently control the temperature of each path, the prior art adopts multiple compressor refrigeration systems, corresponding multiple evaporators, and sets corresponding independent water pumps in the supply liquid circuit. The supply liquid temperature of each path is independently collected and controlled. This type of liquid-cooled device can supply liquid to meet the requirements of different pressures, different flow rates, and different temperatures of multiple paths at the same time. However, there are many compression refrigeration systems, the fluorine pipelines are complex, the occupied space volume is large, it is not conducive to maintenance, and the use cost is high. Summary of the Invention

[0004] (I) Technical Problems to be Solved

[0005] Aiming at the deficiencies of the prior art, the present invention provides a refrigeration method and system for controlling two temperatures with a single compressor. The method of the present invention can be applied to a dual-temperature control system, that is, a set of compressor units or liquid-cooled machines is adopted to realize the temperature output and control of two paths. When used for testing, two products can be tested simultaneously. The equipment prepared by using the principle of this method has a smaller overall size, lower power, and reduced failure rate, and solves the technical problem that a single-compressor refrigeration system in the prior art cannot control multiple paths at different temperatures.

[0006] (II) Technical Solutions

[0007] To achieve the above object, the present invention provides the following technical solution: A refrigeration method for controlling two temperatures with a single compressor, the method comprising the following steps:

[0008] S1. Select a cooling liquid medium and add it to a normal-temperature water storage tank, and start the control program to control the first water path and the second water path included in the water circuit system;

[0009] S2. Inject the cooling liquid medium in the normal-temperature water storage tank into two independent first buffer water boxes and second buffer water boxes in the two water paths respectively, and independently adjust the flow rate or pressure by opening the corresponding first external circulation pump and second external circulation pump in the two water paths;

[0010] S3. Turn on the corresponding No. 1 internal circulation pump and No. 2 internal circulation pump in the two water circuits respectively. Through the No. 1 water circuit, the cooling liquid medium circulates in the No. 1 evaporator and the No. 1 buffer water box; through the No. 2 water circuit, the cooling liquid medium circulates in the No. 2 evaporator and the No. 2 buffer water box.

[0011] S4. Turn on the refrigeration compressor, and then turn on the cold bypass solenoid valve and the hot bypass solenoid valve for adjustment, so that the refrigeration compressor is in the operating state but does not output refrigeration capacity and heating capacity to the No. 1 evaporator and the No. 2 evaporator.

[0012] S5. According to the temperature set in the control program, the PID controller adjusts the No. 1 refrigeration valve and the No. 2 refrigeration valve respectively to deliver liquid refrigerant to the corresponding No. 1 evaporator and No. 2 evaporator. The refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time.

[0013] S6. According to the temperature set in the control program, the PID controller adjusts the No. 1 heater and the No. 2 heater respectively to deliver heating amount to the cooling liquid medium in the corresponding No. 1 buffer water box and No. 2 buffer water box, and the internal circulation exchanges heat in real time.

[0014] S7. Through the exhaust temperature T1 and the suction temperature T2 of the refrigeration system, automatically adjust the on-off of the cold bypass solenoid valve and the hot bypass solenoid valve. The cold liquid and hot gas are mixed and pass through the gas-liquid separator and then return to the refrigeration compressor to keep the refrigeration compressor in a suitable operating state.

[0015] S8. The set temperatures of the two paths can be different. The PID controller will always adjust the refrigeration capacity and the compensation heating amount for temperature control, and the two path channels are not affected by each other.

[0016] Further, the water circuit system includes a normal temperature water storage tank. A liquid filling port is opened above the normal temperature water storage tank, and a liquid level gauge for checking the liquid position in the normal temperature water storage tank is arranged on its side. The outlet of the normal temperature water storage tank branches into two water circuits, which are connected to the No. 1 buffer water box and the No. 2 buffer water box respectively through pipes. The outlets on one side of the No. 1 buffer water box and the No. 2 buffer water box are connected to the No. 1 external circulation pump and the No. 2 external circulation pump respectively through the main pipeline of the water circuit system. The No. 1 external circulation pump and the No. 2 external circulation pump are connected to the working equipment; No. 1 heater and No. 2 heater are respectively installed in the No. 1 buffer water box and the No. 2 buffer water box, and one ends of the No. 1 external circulation pump and the No. 2 external circulation pump are respectively connected with a No. 1 temperature control sensor and a No. 2 temperature control sensor.

[0017] Further, the water outlets on the other sides of the first buffer water box and the second buffer water box are connected to the first internal circulation pump and the second internal circulation pump through the secondary pipeline of the waterway system. The first internal circulation pump is connected to the first evaporator and the first refrigeration valve. After the cooling liquid medium enters the first evaporator through the secondary pipeline of the waterway system, it then returns to the first buffer water box. The second internal circulation pump is connected to the second evaporator and the second refrigeration valve. After the cooling liquid medium enters the second evaporator through the secondary pipeline of the waterway system, it then returns to the second buffer water box.

[0018] Further, one sides of the first evaporator and the second evaporator are respectively connected to the internal circulation pipeline. The first evaporator and the second evaporator are respectively connected to the refrigeration compressor through the one-way valve, the gas-liquid separator and the regenerator connected thereto. The refrigeration compressor is connected to the oil separator, the condenser, the dryer filter and the economizer.

[0019] Further, the refrigeration compressor is connected with a cold bypass branch and a hot bypass branch. The cold bypass branch is connected with a cold bypass throttle pipe and a cold bypass solenoid valve. The hot bypass branch is connected with a hot bypass throttle pipe and a hot bypass solenoid valve.

[0020] Further, in the S5 step, the PID controller adjusts the first refrigeration valve and the second refrigeration valve respectively to supply liquid refrigerant to the corresponding first evaporator and second evaporator. The refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time. An economizer with subcooling control is connected to one side of the first evaporator and the second evaporator. The economizer further reduces the condensation temperature, effectively controls the temperature of the liquid pipe after subcooling between 4°C and 12°C, further improves the evaporation efficiency, increases the required refrigerating capacity, and enables the return gas to directly return to the scroll disk of the refrigeration compressor for compression again, and reciprocates in a cycle.

[0021] Further, in the S7 step, the cold bypass solenoid valve and the hot bypass solenoid valve perform temperature compensation on the refrigerant in the return air pipe, effectively ensuring the return air state of the refrigeration compressor, and the return air temperature of 8°C to 12°C enters the compressor. At this temperature, the mechanical lubrication of the compressor can be in the best state.

[0022] Further, in the S8 step, a regenerator is added to the refrigeration system, and the regenerator is used to separate the heat and cold exchange to prevent the gaseous refrigerant from being subcooled or superheated from returning to the refrigeration compressor.

[0023] Further, high and low pressure gauges and high and low pressure controllers are provided in the refrigeration system. The high and low pressure gauges are used to display the pressure values, and the high and low pressure controllers perform upper and lower limit protection according to the displayed pressure values.

[0024] To achieve the above object, a refrigeration method for controlling two temperatures with a single compressor as described above is programmed into a corresponding refrigeration system for controlling two temperatures with a single compressor or made into a hardware device, and the system is an embedded software system.

[0025] (III) Beneficial Effects

[0026] Compared with the prior art, the present invention provides a refrigeration method for controlling two temperatures with a single compressor, having the following beneficial effects:

[0027] 1. The method of the present invention can be applied to a dual-temperature control system, that is, by using a set of compressor units or liquid chillers, two-way temperature output and control can be achieved. When used for testing, two products can be tested simultaneously. The equipment prepared using the principle of this method has a smaller overall size, lower power, and reduced failure rate.

[0028] 2. Subcooling control is added in the present invention, which can further reduce the condensation temperature and enable the compressor to exert its maximum capacity with the minimum electric power.

[0029] 3. In the present invention, the dual evaporators are of plate heat exchanger design, and the refrigerating capacity is adjusted by an independent PID controller. A one-way valve is designed and installed in the return air pipe to prevent the refrigerant from flowing back to the low-temperature evaporator plate heat exchanger due to negative pressure during the operation of the low-temperature working condition, resulting in abnormal system oil return. When controlling different temperatures, the return air temperatures are one high and one low. They will be mixed first at the front end of the gas-liquid separator, and the cold bypass branch and the hot bypass branch are compensated and adjusted according to the compressor state to reach a return air temperature of about 10°C. This design effectively solves the problem of return air deviation when operating at different temperatures and can ensure the best operating state of the compressor. Description of the Drawings

[0030] Figure 1 is the schematic diagram of the water circuit system of a refrigeration method for controlling two temperatures with a single compressor according to the present invention;

[0031] Figure 2 is the schematic diagram of the refrigeration system of a refrigeration method for controlling two temperatures with a single compressor according to the present invention;

[0032] Figure 3 is the operation screen of a refrigeration system for controlling two temperatures with a single compressor according to the present invention;

[0033] Figure 4 is the schematic diagram of the principle of controlling the temperature of two devices by two liquid chillers in the prior art;

[0034] Figure 5 For Figure 4 the schematic diagram of the principle adopting the method of the present invention;

[0035] Figure 6 For Figure 5Test curve graph of the embodiment;

[0036] In the figure: 1. Cooling liquid medium; 2. Normal temperature water storage tank; 3. First external circulation pump; 4. Second external circulation pump; 5. First buffer water box; 6. Second buffer water box; 7. First internal circulation pump; 8. Second internal circulation pump; 9. First evaporator; 10. Second evaporator; 11. Refrigeration compressor; 12. Cold bypass solenoid valve; 13. Hot bypass solenoid valve; 14. First refrigeration valve; 15. Second refrigeration valve; 16. First heater; 17. Second heater; 18. Liquid filling port; 19. Liquid level gauge; 20. Main pipeline of the water system; 21. First temperature control sensor; 22. Second temperature control sensor; 23. Sub-pipeline of the water system; 24. Check valve; 25. Gas-liquid separator; 26. Regenerator; 27. Oil separator; 28. Condenser; 29. Drying filter; 30. Economizer; 31. Cold bypass throttle pipe; 32. Hot bypass throttle pipe; 33. High and low pressure gauge; 34. High and low pressure controller. Specific implementation manner

[0037] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0038] Please refer to Figures 1 - 2 , a refrigeration method for controlling two temperatures with a single compressor, comprising the following steps:

[0039] S1. Select the cooling liquid medium 1 and add it to the normal temperature water storage tank 2, and start the control program to control the first water circuit and the second water circuit included in the water system;

[0040] S2. Inject the cooling liquid medium 1 in the normal temperature water storage tank 2 into two independent first buffer water boxes 5 and second buffer water boxes 6 in the two water circuits respectively, and separately turn on the corresponding first external circulation pump 3 and second external circulation pump 4 in the two water circuits to independently adjust the flow rate or pressure;

[0041] S3. Separately turn on the corresponding first internal circulation pump 7 and second internal circulation pump 8 in the two water circuits, and make the cooling liquid medium 1 circulate in the first evaporator 9 and the first buffer water box 5 through the first water circuit; make the cooling liquid medium 1 circulate in the second evaporator 10 and the second buffer water box 6 through the second water circuit;

[0042] S4. Turn on the refrigeration compressor 11, and then turn on the cold bypass valve 12 and the hot bypass solenoid valve 13 to adjust, so that the refrigeration compressor 11 is in the operating state but does not output refrigeration capacity and heating capacity to the first evaporator 9 and the second evaporator 10;

[0043] S5. According to the temperature set in the control program, the PID controller adjusts the first refrigeration valve 14 and the second refrigeration valve 15 respectively to deliver liquid refrigerant to the corresponding first evaporator 9 and second evaporator 10. The refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time for cyclic heat exchange. When the PID controller adjusts the first refrigeration valve 14 and the second refrigeration valve 15 respectively to deliver liquid refrigerant to the corresponding first evaporator 9 and second evaporator 10, the refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time for cyclic heat exchange. An economizer 30 for subcooling control is connected and arranged on one side of the first evaporator 9 and the second evaporator 10. The economizer 30 further reduces the condensation temperature, effectively controls the temperature of the liquid pipe after subcooling between 4°C and 12°C, further improves the evaporation efficiency, increases the required refrigerating capacity, enables the return gas to directly return to the scroll disk of the refrigeration compressor 11 for re-compression, and reciprocates in a cycle;

[0044] S6. According to the temperature set in the control program, the PID controller adjusts the first heater 16 and the second heater 17 respectively to supply heating quantity to the cooling liquid medium 1 in the corresponding first buffer water box 5 and second buffer water box 6, and the internal circulation exchanges heat in real time for cyclic heat exchange;

[0045] S7. Through the exhaust gas temperature T1 and the suction gas temperature T2 of the refrigeration system, the on-off of the cold bypass valve 12 and the hot bypass solenoid valve 13 is automatically adjusted. The cold liquid and the hot gas are mixed and pass through the gas-liquid separator and then return to the refrigeration compressor 11 to keep the refrigeration compressor 11 in a proper operating state; the cold bypass valve 12 and the hot bypass solenoid valve 13 perform temperature compensation on the refrigerant in the return air pipe, effectively ensuring the return air state of the refrigeration compressor 11, and the return air temperature reaches 8°C to 12°C when entering the compressor. At this temperature, the mechanical lubrication of the compressor can be in the best state;

[0046] S8. The two set temperatures can be different. The PID controller will always adjust the refrigerating capacity and the compensation heating quantity for temperature control, and the two channels are not affected by each other; a regenerator 26 is added to the refrigeration system, and the regenerator 26 is used to separate the heat and cold exchange to prevent the supercooled or superheated gaseous refrigerant from returning to the refrigeration compressor 11.

[0047] In the above embodiment, the waterway system includes a normal-temperature water storage tank 2. A liquid filling port 18 is provided above the normal-temperature water storage tank 2, and a liquid level gauge 19 for checking the liquid level in the normal-temperature water storage tank 2 is arranged on its side. The outlet of the normal-temperature water storage tank 2 branches into two waterways, which are respectively connected to a first buffer water box 5 and a second buffer water box 6 through pipelines. The water outlets on one side of the first buffer water box 5 and the second buffer water box 6 are respectively connected to a first external circulation pump 3 and a second external circulation pump 4 through the main pipeline 20 of the waterway system, and the first external circulation pump 3 and the second external circulation pump 4 are connected to the working equipment; a first heater 16 and a second heater 17 are respectively installed in the first buffer water box 5 and the second buffer water box 6, and a first temperature control sensor 21 and a second temperature control sensor 22 are respectively arranged at one ends of the first external circulation pump 3 and the second external circulation pump 4; the water outlets on the other side of the first buffer water box 5 and the second buffer water box 6 are respectively connected to a first internal circulation pump 7 and a second internal circulation pump 8 through the secondary pipeline 23 of the waterway system. The first internal circulation pump 7 is connected to a first evaporator 9 and a first refrigeration valve 14. The cooling liquid medium 1 enters the first evaporator 9 through the secondary pipeline 23 of the waterway system and then returns to the first buffer water box 5. The second internal circulation pump 8 is connected to a second evaporator 10 and a second refrigeration valve 15. The cooling liquid medium 1 enters the second evaporator 10 through the secondary pipeline 23 of the waterway system and then returns to the second buffer water box 6; one sides of the first evaporator 9 and the second evaporator 10 are respectively connected to an internal circulation pipeline, and the first evaporator 9 and the second evaporator 10 are respectively connected to a refrigeration compressor 11 through a one-way valve 24, a gas-liquid separator 25 and a regenerator 26. The refrigeration compressor 11 is connected to an oil separator 27, a condenser 28, a drying filter 29 and an economizer 30; the refrigeration compressor 11 is connected with a cold bypass branch and a hot bypass branch. A cold bypass throttle pipe 31 and a cold bypass solenoid valve 12 are connected to the cold bypass branch, and a hot bypass throttle pipe 32 and a hot bypass solenoid valve 13 are connected to the hot bypass branch; a high-low pressure gauge 33 and a high-low pressure controller 34 are arranged in the refrigeration system. The high-low pressure gauge 33 is used to display the pressure value, and the high-low pressure controller 34 performs upper and lower limit protection according to the displayed pressure value.

[0048] To achieve the above object, the above-mentioned refrigeration method for controlling two temperatures with a single compressor is compiled into a corresponding refrigeration system for controlling two temperatures with a single compressor or made into a hardware device, and the system is an embedded software system.

[0049] Embodiment 1:

[0050] In use, pure water is selected as the cooling liquid medium 1, or one of 30% ethylene glycol, 50% ethylene glycol or 60% ethylene glycol is used as the cooling liquid medium 1. The coolant medium 1 is added to the normal temperature storage water tank 2, and the control program is started to control the first water circuit and the second water circuit. At this time, the cooling liquid medium 1 in the normal temperature storage water tank 2 is respectively injected into two independent first buffer water boxes 5 and second buffer water boxes 6 in the two water circuits. The corresponding first external circulation pump 3 and second external circulation pump 4 in the two water circuits are respectively opened to independently adjust the flow rate or pressure. Then, the corresponding first internal circulation pump 7 and second internal circulation pump 8 in the two water circuits are respectively opened. Through the first water circuit, the cooling liquid medium 1 circulates in the first evaporator 9 and the first buffer water box 5; through the second water circuit, the cooling liquid medium 1 circulates in the second evaporator 10 and the second buffer water box 6. At this time, the refrigeration compressor 11 is started, and then the cold bypass valve 12 and the hot bypass solenoid valve 13 are adjusted to make the refrigeration compressor 11 in the operating state but not output refrigeration capacity and heating capacity to the first evaporator 9 and the second evaporator 10.

[0051] Please refer to Figure 3 , the operator sets the initial temperature of the first water circuit in the control program to -30°C, the liquid outlet flow rate to 10 L / min, the initial temperature of the second water circuit to 65°C, and the liquid outlet flow rate to 16 L / min. According to the temperature set in the control program above, when the actual load temperature is higher than the set value and cooling is required, the PID controller adjusts the first refrigeration valve 14 and the second refrigeration valve 15 respectively to deliver liquid refrigerant to the corresponding first evaporator 9 and second evaporator 10. The refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time; when the PID controller adjusts the first refrigeration valve 14 and the second refrigeration valve 15 respectively to deliver liquid refrigerant to the corresponding first evaporator 9 and second evaporator 10, the refrigerant evaporates and absorbs heat in the evaporator, and exchanges heat with the passing coolant in real time. An economizer 30 with subcooling control is connected and arranged on one side of the first evaporator 9 and the second evaporator 10. The economizer 30 further reduces the condensation temperature, effectively controls the liquid pipe temperature after subcooling between 4°C and 12°C, further improves the evaporation efficiency, increases the required refrigeration capacity, and makes the return gas directly return to the scroll disk of the refrigeration compressor 11 for compression again, and reciprocates; when the actual load temperature is lower than the set value and heating is required to increase the temperature, the PID controller adjusts the first heater 16 and the second heater 17 respectively to deliver heating quantity to the cooling liquid medium 1 in the corresponding first buffer water box 5 and second buffer water box 6, and the internal circulation exchanges heat in real time; in this way, the control temperature is updated in real time, so that the actual value of the temperature of the first water circuit gradually reaches -29.99°C, and the actual value of the temperature of the second water circuit gradually reaches +65°C, realizing that a set of compressor unit or liquid cooler can realize the temperature output and control of two paths.

[0052] Example 2:

[0053] The refrigeration method of a single compressor controlling two temperatures can be applied to the testing of devices such as motors in new energy vehicles. The purpose of testing devices such as motors is to verify the power output, torque, and efficiency of the motors, ensure that the dynamic performance of the vehicle meets the design requirements, and timely repair problems to improve performance. Common testing requirements include the antifreeze cooling test of both the vehicle controller and the motor, testing different working conditions of temperature and flow rate, and obtaining relevant data and test results. The common testing method in the prior art is to connect two devices, namely the controller and the motor, separately. As Figure 4 shown, two liquid coolers are used. The No. 1 liquid cooler is connected to the motor, and the No. 2 liquid cooler is connected to the controller. In this way, two liquid coolers are required to obtain the operating temperatures of two different devices, increasing the equipment cost. Therefore, the method of the present invention can be used instead. As Figure 5 shown, one liquid cooler can simultaneously control two different temperatures of the motor and the controller through the technical solution provided by the present invention. For example, when the motor needs to meet the temperature range of -30°C to +85°C alternating, and the flow rate requirement is 6 to 10 L / min, at the same time, the controller needs to maintain the temperature range of 23°C and the flow rate requirement is 12 L / min. The test curve is as Figure 6 shown. The motor requires a test flow rate of 10 L / min above 0°C and 6 L / min below 0°C, and the controller requires a flow rate of 12 L / min. By adopting a system that uses a set of liquid coolers to control two different temperatures of two devices, the installation link and data integration in the testing process can be simplified, and the failure rate can be reduced.

[0054] It should be noted that, if in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the said element.

[0055] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A refrigeration method for controlling two temperatures with a single compressor, characterized in that: The method includes the following steps: S1. Select a cooling liquid medium (1) and add it to the normal temperature water storage tank (2), and start the control program to control the first water circuit and the second water circuit included in the water circuit system; S2. Inject the cooling liquid medium (1) in the normal temperature water storage tank (2) into two independent first buffer water boxes (5) and second buffer water boxes (6) in the two water circuits respectively, and separately turn on the corresponding first external circulation pump (3) and second external circulation pump (4) in the two water circuits to independently adjust the flow rate or pressure; S3. Separately turn on the corresponding first internal circulation pump (7) and second internal circulation pump (8) in the two water circuits. Through the first water circuit, the cooling liquid medium (1) circulates inside the first evaporator (9) and the first buffer water box (5); through the second water circuit, the cooling liquid medium (1) circulates inside the second evaporator (10) and the second buffer water box (6); S4. Turn on the refrigeration compressor (11), then turn on and adjust the cold bypass solenoid valve (12) and the hot bypass solenoid valve (13), so that the refrigeration compressor (11) is in an operating state but does not output cooling capacity and heating capacity to the first evaporator (9) and the second evaporator (10); S5. According to the temperature set in the control program, the PID controller respectively adjusts the first refrigeration valve (14) and the second refrigeration valve (15) to deliver liquid refrigerant to the corresponding first evaporator (9) and second evaporator (10). The refrigerant evaporates and absorbs heat in the evaporator, and circulates and exchanges heat with the passing coolant in real time; S6. According to the temperature set in the control program, the PID controller respectively adjusts the first heater (16) and the second heater (17) to deliver heating quantity to the cooling liquid medium (1) in the corresponding first buffer water box (5) and second buffer water box (6), and the internal circulation exchanges heat in real time; S7. Automatically adjust the on-off of the cold bypass solenoid valve (12) and the hot bypass solenoid valve (13) through the exhaust temperature T1 and the suction temperature T2 of the refrigeration system. The cold liquid and the hot gas are mixed and pass through the gas-liquid separator and then return to the refrigeration compressor (11) to keep the refrigeration compressor (11) in a suitable operating state; S8. The set temperatures of the two paths can be different. The PID controller will always adjust the cooling capacity and the compensation heating quantity for temperature control, and the two path channels do not affect each other.

2. The refrigeration method for controlling two temperatures by a single compressor according to claim 1, characterized in that: The waterway system includes a normal-temperature water storage tank (2). A liquid filling port (18) is provided above the normal-temperature water storage tank (2), and a liquid level gauge (19) for checking the liquid level in the normal-temperature water storage tank (2) is arranged on its side. The outlet of the normal-temperature water storage tank (2) branches into two waterways, which are respectively connected to a first buffer water box (5) and a second buffer water box (6) through pipelines. The outlets on one side of the first buffer water box (5) and the second buffer water box (6) are respectively connected to a first external circulation pump (3) and a second external circulation pump (4) through the main waterway pipeline (20) of the waterway system. The first external circulation pump (3) and the second external circulation pump (4) are connected to the working equipment. A first heater (16) and a second heater (17) are respectively installed in the first buffer water box (5) and the second buffer water box (6). One ends of the first external circulation pump (3) and the second external circulation pump (4) are respectively connected with a first temperature control sensor (21) and a second temperature control sensor (22).

3. A refrigeration method for controlling two temperatures with a single compressor according to claim 2, characterized in that: The outlets on the other side of the first buffer water box (5) and the second buffer water box (6) are respectively connected to a first internal circulation pump (7) and a second internal circulation pump (8) through the auxiliary waterway pipeline (23) of the waterway system. The first internal circulation pump (7) is connected to a first evaporator (9) and a first refrigeration valve (14). The cooling liquid medium (1) enters the first evaporator (9) through the auxiliary waterway pipeline (23) of the waterway system and then returns to the first buffer water box (5). The second internal circulation pump (8) is connected to a second evaporator (10) and a second refrigeration valve (15). The cooling liquid medium (1) enters the second evaporator (10) through the auxiliary waterway pipeline (23) of the waterway system and then returns to the second buffer water box (6).

4. A refrigeration method for controlling two temperatures with a single compressor according to claim 3, characterized in that: One sides of the first evaporator (9) and the second evaporator (10) are respectively connected to internal circulation pipelines. The first evaporator (9) and the second evaporator (10) are respectively connected to a refrigeration compressor (11) through a check valve (24), a gas-liquid separator (25) and a regenerator (26) which are connected. The refrigeration compressor (11) is connected to an oil separator (27), a condenser (28), a dryer filter (29) and an economizer (30).

5. A refrigeration method for controlling two temperatures with a single compressor according to claim 1 or 4, characterized in that: The refrigeration compressor (11) is connected with a cold bypass branch and a hot bypass branch. A cold bypass throttle pipe (31) and a cold bypass solenoid valve (12) are connected to the cold bypass branch. A hot bypass throttle pipe (32) and a hot bypass solenoid valve (13) are connected to the hot bypass branch.

6. The refrigeration method for controlling two temperatures with a single compressor according to claim 1, characterized in that: In the step S5, the PID controller adjusts the first refrigeration valve (14) and the second refrigeration valve (15) respectively to deliver liquid refrigerant to the corresponding first evaporator (9) and second evaporator (10). The refrigerant evaporates and absorbs heat in the evaporator, and circulates and exchanges heat with the passing coolant in real time. An economizer (30) for subcooling control is connected and arranged on one side of the first evaporator (9) and the second evaporator (10). The economizer (30) further reduces the condensation temperature, effectively controls the temperature of the liquid pipe after subcooling to be between 4°C and 12°C, further improves the evaporation efficiency, increases the required refrigerating capacity, and enables the returned gas to directly return to the scroll plate of the refrigeration compressor (11) for compression again, and reciprocates in a cycle.

7. A refrigeration method for controlling two temperatures with a single compressor according to claim 1, characterized in that: In the step S7, the cold bypass solenoid valve (12) and the hot bypass solenoid valve (13) perform temperature compensation on the refrigerant in the return air pipe, effectively ensuring the return air state of the refrigeration compressor (11), and the return air temperature of 8°C to 12°C enters the compressor. At this temperature, the mechanical lubrication of the compressor can be in the best state.

8. A refrigeration method for controlling two temperatures with a single compressor according to claim 1, characterized in that: In the step S8, a regenerator (26) is added to the refrigeration system, and the regenerator (26) is used to separate the heat and cold exchange to prevent the supercooled or superheated gaseous refrigerant from returning to the refrigeration compressor (11).

9. The refrigeration method for controlling two temperatures with a single compressor according to claim 1, characterized in that: A high and low pressure gauge (33) and a high and low pressure controller (34) are arranged in the refrigeration system. The high and low pressure gauge (33) is used to display the pressure value, and the high and low pressure controller (34) performs upper and lower limit protection according to the displayed pressure value.

10. A refrigeration system that controls two temperatures with a single compressor, characterized in that: A system prepared by using the refrigeration method for controlling two temperatures with a single compressor according to any one of claims 1-9, and the system is an embedded software system.

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