Liquid temperature control unit and method thereof

Abstract

According to the liquid temperature control unit and the method thereof, the liquid temperature control unit is not affected by the external environment temperature, the constant heating performance of a secondary refrigerant can be guaranteed, and normal use of the secondary refrigerant is guaranteed; the liquid temperature control unit comprises a refrigerant system and a secondary refrigerant system, a heat exchanger is connected between the refrigerant system and the secondary refrigerant system, and the heat exchanger comprises a first inlet, a second inlet, a first outlet and a second outlet; the refrigerant system comprises a compressor, a condenser, a valve assembly, a control valve and a throttling mechanism, the condenser is provided with a condensation fan, and the secondary refrigerant system comprises a water pump; a liquid inlet of the secondary refrigerant system is connected to the second inlet after being connected with a water pump, the first outlet is connected with an inlet of the compressor, an outlet of the condenser is connected with the throttling mechanism after passing through the control valve, an outlet of the throttling mechanism is connected with the first inlet, output of the compressor after refrigerant compression is divided into two paths after passing through the connecting valve assembly, one path enters the condenser, and the other path enters the second inlet. And the other path is connected to a connecting pipeline between the control valve and the throttling mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of liquid temperature control, and in particular to a liquid temperature control unit and a method thereof. Background Art

[0002] In air-conditioning engineering, industrial production and scientific experiments, refrigeration devices are often used to indirectly cool the objects to be cooled, or to transport the cold generated by the refrigeration device over long distances. At this time, an intermediate substance is required, which is cooled in the evaporator and then used to cool the objects to be cooled. This intermediate substance is called a coolant.

[0003] Conventional refrigerant liquid temperature control units with compressors as the core generally use the compressor to cool the refrigerant liquid (such as water, ethylene glycol aqueous solution, oil and other liquids) when cooling; and when heating, the refrigerant liquid is usually heated by connecting an electric heater in the refrigerant liquid pipeline, that is, turning on the electric heater to heat the refrigerant liquid flowing through, or by running a heat pump (reverse Carnot cycle) to heat the refrigerant liquid. However, the above-mentioned temperature control methods have the following disadvantages:

[0004] 1. When the heating method of inserting an electric heater in series in the refrigerant liquid pipeline is adopted, the flow resistance of the refrigerant will be increased because the electric heating component is inserted in series in the refrigerant system. At the same time, the surface temperature of the electric heating is relatively high during operation, and the refrigerant is prone to generate bubbles on the heater surface, thereby affecting the normal life of the refrigerant. At the same time, the bubbles generated will cause cavitation on the high-speed rotating impeller surface of the pump that drives the refrigerant flow;

[0005] 2. When heating is performed by operating a heat pump (reverse Carnot cycle), its heating capacity is affected by the external ambient temperature. For example, when the external ambient temperature is low, the evaporator in the heat pump circulation system will frost. Once the evaporator is frosted, defrosting is required. However, whether hot gas defrosting, electric defrosting or Carnot cycle refrigeration defrosting is used, it will cause fluctuations in the heating of the refrigerant, thereby affecting the constant heating performance of the refrigerant. Summary of the invention

[0006] In view of the above problems, the present invention provides a liquid temperature control unit and method thereof, which is not affected by the external ambient temperature, can ensure constant heating performance of the refrigerant, and ensure normal use of the refrigerant.

[0007] The present invention adopts the following technical scheme: a liquid temperature control unit, comprising a refrigerant system and a coolant system, wherein a heat exchanger is connected between the refrigerant system and the coolant system, and the heat exchanger comprises a first inlet, a second inlet, a first outlet, and a second outlet; the refrigerant system comprises a compressor, a condenser, a valve assembly, a control valve, and a throttling mechanism, the condenser is provided with a condensing fan, and the coolant system comprises a water pump; the liquid inlet of the coolant system is connected to the second inlet after being connected to the water pump, the first outlet is connected to the inlet of the compressor, the outlet of the condenser is connected to the throttling mechanism after being passed through the control valve, and the outlet of the throttling mechanism is connected to the first inlet, and the output of the compressor after compressing the refrigerant is divided into two paths after being connected to the valve assembly, one path enters the condenser, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism.

[0008] Furthermore, the valve assembly includes a first solenoid valve and a second solenoid valve, and the compressor divides the output of the compressed refrigerant into two paths, one path enters the condenser after passing through the first solenoid valve, and the other path passes through the second solenoid valve and is connected to the connecting pipeline between the control valve and the throttling mechanism;

[0009] Furthermore, the valve assembly adopts a three-way valve, and the compressor divides the output of the refrigerant after compression into two paths after connecting to the three-way valve, one path enters the condenser through one outlet of the three-way valve, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism after passing through another outlet of the three-way valve;

[0010] Further, a pressure sensor is provided on the connecting pipeline between the first outlet of the heat exchanger and the inlet of the compressor;

[0011] A liquid temperature control method, comprising:

[0012] During refrigeration operation, one pipeline between the compressor and the condenser is connected, and the other pipeline outputted from the compressor is closed. Then, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas and outputs it to the condenser for cooling. Then, the gaseous refrigerant passes through the control valve and the throttling mechanism in sequence and enters the heat exchanger to cool the coolant passing through the heat exchanger. The cooled coolant flows out through the second outlet, and the refrigerant flows out through the first outlet and returns to the compressor again.

[0013] During heating operation, one pipeline between the compressor and the condenser is closed, and the other pipeline of the compressor output is opened. Then, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas and then flows to the throttling mechanism. After entering the heat exchanger, it exchanges heat with the coolant flowing through the heat exchanger. The refrigerant after the heat exchange returns to the compressor again, and the heated coolant flows out through the second outlet.

[0014] Furthermore, during refrigeration operation, the following steps are included:

[0015] S1.1. According to a refrigeration request, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous state, and then the refrigerant flows into the condenser through the valve assembly and becomes a medium-temperature and high-pressure liquid state after being cooled in the condenser;

[0016] S1.2, medium-temperature and high-pressure liquid refrigerant passes through the control valve and throttling mechanism in sequence;

[0017] S1.3, the low-temperature and low-pressure gas-liquid mixed refrigerant flowing out of the throttling mechanism enters the heat exchanger for evaporation and heat absorption, and the coolant flowing through the heat exchanger is cooled and flows out through the second outlet. At this time, the refrigerant is completely evaporated into gas in the heat exchanger and returns to the compressor again, and the step S1.1 is repeated to continue the cycle for refrigeration;

[0018] Furthermore, during the heating operation, the following steps are included:

[0019] S2.1. According to a heating request, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas, and then the refrigerant flows to the throttling mechanism through the valve assembly;

[0020] S2.2, the high-temperature and high-pressure gaseous refrigerant is depressurized by the throttling mechanism into a high-temperature and low-pressure gaseous refrigerant and then enters the heat exchanger;

[0021] S2.3, the high-temperature, low-pressure gaseous refrigerant exchanges heat with the coolant flowing through the heat exchanger in the heat exchanger, and the high-temperature, low-pressure gaseous refrigerant heats the coolant, and the heated coolant flows out through the second outlet, and the refrigerant becomes a low-temperature, low-pressure gaseous refrigerant, and then returns to the compressor again, and repeats step S2.1 to continue the cycle for heating;

[0022] Further, the saturation temperature of the refrigerant entering the heat exchanger is lower than the temperature of the secondary refrigerant flowing through the heat exchanger.

[0023] The beneficial effect of the present invention is that it allows the refrigerant to carry the heat generated by the compressor's own power consumption when running, and enters the heat exchanger to heat the refrigerant liquid flowing through. The refrigerant has no phase change heat absorption process, no defrosting process, and will not affect the temperature fluctuation during heating operation. The heating capacity is not affected by the external ambient temperature, and can ensure that the refrigerant can be continuously heated and heated at different ambient temperatures, thereby ensuring the constant heating performance of the refrigerant and ensuring the normal use of the refrigerant, and has good economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a connection diagram of Embodiment 1 of the present invention;

[0025] Figure 2 It is a connection diagram of the second embodiment of the present invention. DETAILED DESCRIPTION

[0026] Embodiment 1

[0027] like Figure 1 As shown, a liquid temperature control unit of the present invention includes a refrigerant system and a coolant system, wherein a heat exchanger 1 is connected between the refrigerant system and the coolant system, and the heat exchanger 1 includes a first inlet, a second inlet, a first outlet, and a second outlet; the refrigerant system includes a compressor 2, a condenser 3, a valve assembly, a control valve, and a throttling mechanism 5, and the condenser 3 is provided with a condensing fan 6, and the coolant system includes a water pump 7; the liquid inlet 12 of the coolant system is connected to the second inlet after being connected to the water pump 7, the first outlet is connected to the inlet of the compressor 2, the outlet of the condenser 3 is connected to the throttling mechanism 5 after being connected to the control valve, and the outlet of the throttling mechanism 5 is connected to the first inlet, and the compressor 2 divides the output of the refrigerant after compression into two paths after being connected to the valve assembly, one path enters the condenser 3, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism 5.

[0028] The valve assembly includes a first solenoid valve 8 and a second solenoid valve 9. The compressor 2 divides the output of the compressed refrigerant into two paths. One path enters the condenser 3 after passing through the first solenoid valve 8, and the other path passes through the second solenoid valve 9 and is connected to the connecting pipeline between the one-way valve 4 and the throttling mechanism 5. Among them, the control valve in Example 1 adopts the one-way valve 4.

[0029] In order to prevent the high-temperature, low-pressure gaseous refrigerant entering the heat exchanger 1 from condensing into liquid in the heat exchanger 1, a pressure sensor P1 is provided on the connecting pipeline between the first outlet of the heat exchanger 1 and the inlet of the compressor 2. The corresponding refrigerant saturation point temperature (condensation point temperature) can be directly obtained by the pressure value detected by the pressure sensor P1. The method of obtaining the refrigerant saturation temperature by the pressure value is an existing method, and the corresponding saturation temperature can be obtained by directly comparing the pressure value with the existing table parameters;

[0030] The pressure of the refrigerant entering the heat exchanger 1 is controlled by adjusting the opening of the throttling mechanism 5, so that the saturation temperature of the refrigerant entering the heat exchanger 1 is lower than the temperature of the coolant flowing through the heat exchanger 1. In this way, the refrigerant will not condense into liquid in the heat exchanger 1, and the refrigerant entering the compressor 2 is still in gaseous state, ensuring the operating reliability of the compressor 2.

[0031] Embodiment 2

[0032] like Figure 2 As shown, the valve assembly adopts a three-way valve 10, and the compressor 2 divides the output of the compressed refrigerant into two paths after connecting to the three-way valve 10. One path enters the condenser 3 through one outlet of the three-way valve 10, and the other path is connected to the connecting pipeline between the solenoid valve 11 and the throttling mechanism 5 after passing through the other outlet of the three-way valve 10.

[0033] The control valve in the second embodiment uses a solenoid valve 11 , and the flow path of the refrigerant is opened or closed by switching the solenoid valve 11 .

[0034] By adopting the structure of the first or second embodiment, the present invention further provides a liquid temperature control method, comprising:

[0035] During refrigeration operation, one pipeline between the compressor 2 and the condenser 3 is connected, and the other pipeline outputted from the compressor 2 is closed. Then, the compressor 2 compresses the gaseous refrigerant into a high-temperature and high-pressure gas and outputs it to the condenser 3 for cooling. Then, the gaseous refrigerant passes through the control valve and the throttling mechanism 5 in sequence and enters the heat exchanger 1 to cool the coolant flowing through the heat exchanger 1. The cooled coolant flows out through the second outlet, and the refrigerant flows out through the first outlet and returns to the compressor 2 again.

[0036] Specifically, during refrigeration operation, the following steps are included:

[0037] S1.1. According to the refrigeration request, the compressor 2 compresses the low-pressure and low-temperature refrigerant in the gaseous state into a high-temperature and high-pressure gaseous state, and then the refrigerant flows into the condenser 3 through the valve assembly (that is, at this time, the first solenoid valve 8 is opened and the second solenoid valve 9 is closed; or one of the outlets connected to the condenser 3 of the three-way valve 10 is opened and the other outlet is closed) for cooling, and the heat is taken away by the air circulated by the condensing fan 6 through the condenser 3, and the refrigerant is cooled in the condenser 3 and becomes a medium-temperature and high-pressure liquid refrigerant;

[0038] S1.2, the medium-temperature and high-pressure liquid refrigerant flows through the control valve and is throttled in the throttling mechanism 5, that is, the refrigerant coming out of the throttling mechanism 5 is a low-temperature and low-pressure gas-liquid mixture refrigerant;

[0039] S1.3, the low-temperature and low-pressure gas-liquid mixed refrigerant flowing out of the throttling mechanism 5 enters the heat exchanger 1 for evaporation and heat absorption, and the coolant flowing through the heat exchanger 1 is cooled and flows out through the second outlet. At this time, the refrigerant is completely evaporated into gas in the heat exchanger 1 and returns to the compressor 2 again, and step S1.1 is repeated to continue the cycle for refrigeration;

[0040] During heating operation, one pipeline between the compressor 2 and the condenser 3 is closed, and the other pipeline outputted from the compressor 2 is opened. Then, the compressor 2 compresses the gaseous refrigerant into a high-temperature and high-pressure gas and then flows to the throttling mechanism 5. After entering the heat exchanger 1, the gaseous refrigerant exchanges heat with the secondary refrigerant flowing through the heat exchanger 1. After the heat exchange, the refrigerant returns to the compressor 2 again, and the heated secondary refrigerant flows out through the second outlet.

[0041] Specifically, during the heating operation, the following steps are included:

[0042] S2.1. According to the heating request, after the gaseous refrigerant enters the compressor 2, it is compressed and absorbs the heat generated by the motor of the compressor 2, and becomes a high-temperature and high-pressure gas. Then the refrigerant flows to the pipeline where the throttling mechanism 5 is located through the valve assembly (that is, at this time, the first solenoid valve 8 is closed and the second solenoid valve 9 is opened; or one of the outlets connected to the condenser 3 of the three-way valve 10 is closed and the other outlet is opened), and the pipeline connected to the condenser 3 is blocked by the control valve;

[0043] S2.2, the high-temperature and high-pressure gaseous refrigerant is throttled and depressurized by the throttling mechanism 5 to become the high-temperature and low-pressure gaseous refrigerant and then enters the heat exchanger 1;

[0044] S2.3, the high-temperature and low-pressure gaseous refrigerant exchanges heat with the coolant flowing through the heat exchanger 1 in the heat exchanger 1, and the high-temperature and low-pressure gaseous refrigerant heats the coolant, and the heated coolant flows out through the second outlet. At the same time, the refrigerant becomes a low-temperature and low-pressure gaseous refrigerant, and then returns to the compressor 2 again, and repeats step S2.1 to continue the cycle for heating.

[0045] When the present invention is in heating operation, after the high-temperature and high-pressure refrigerant comes out of the compressor 2, it is throttled and reduced in pressure by the throttling mechanism 5, and the gaseous refrigerant becomes a high-temperature and low-pressure refrigerant. The high-temperature and low-pressure refrigerant is allowed to enter the heat exchanger 1 to heat the refrigerant liquid flowing through. At the same time, the refrigerant entering the heat exchanger 1 is in a low-pressure state, which prevents the refrigerant from condensing into a liquid in the heat exchanger 1 (the refrigerant condensed into a liquid will cause damage to the compressor 2 after entering the compressor 2). The heat of the refrigerant comes from the power consumption of the compressor 2 itself when it is running. The refrigerant does not have a phase change and heat absorption process, so there is no defrosting. In this mode, the heating capacity is not affected by the external ambient temperature, which ensures that the refrigerant liquid can be continuously heated and heated under various ambient temperatures. At the same time, a variable frequency compressor 2 can be used, and the heating capacity can be adjusted by adjusting the speed of the compressor 2.

[0046] In summary, by allowing the low-pressure gaseous refrigerant to carry the heat generated by the compressor 2's own power consumption during operation, it enters the heat exchanger 1 to heat the liquid flowing through it. There is no defrosting process, which will not affect the temperature fluctuation during the heating operation, and is not affected by the external ambient temperature. The heating capacity is continuous and stable. In addition, the compressor 2 can adopt a variable frequency compressor 2, which can adjust the heating capacity in multiple stages, and the liquid heating is more stable. In addition, the variable frequency compressor 2 is used, and the heating start is a soft start, and there will be no large impact current (the existing electric heater will generate a large starting impact current when starting).

[0047] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0048] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A liquid temperature control unit, comprising a refrigerant system and a coolant system, characterized in that: A heat exchanger is connected between the refrigerant system and the coolant system, and the heat exchanger includes a first inlet, a second inlet, a first outlet, and a second outlet; the refrigerant system includes a compressor, a condenser, a valve assembly, a control valve, and a throttling mechanism, the condenser is equipped with a condensing fan, and the coolant system includes a water pump; the liquid inlet of the coolant system is connected to the second inlet after being connected to the water pump, the first outlet is connected to the inlet of the compressor, the outlet of the condenser is connected to the throttling mechanism after passing through the control valve, and the outlet of the throttling mechanism is connected to the first inlet, and the output of the compressor after compressing the refrigerant is divided into two paths after being connected to the valve assembly, one path enters the condenser, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism.

2. A liquid temperature control unit according to claim 1, characterized in that: The valve assembly includes a first solenoid valve and a second solenoid valve. The compressor divides the output of the compressed refrigerant into two paths, one path enters the condenser after passing through the first solenoid valve, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism after passing through the second solenoid valve.

3. A liquid temperature control unit according to claim 1, characterized in that: The valve assembly adopts a three-way valve, and the compressor divides the output of the compressed refrigerant into two paths after connecting to the three-way valve. One path enters the condenser through one of the outlets of the three-way valve, and the other path is connected to the connecting pipeline between the control valve and the throttling mechanism after passing through the other outlet of the three-way valve.

4. A liquid temperature control unit according to any one of claims 2 or 3, characterized in that: A pressure sensor is provided on a connecting pipeline between the first outlet of the heat exchanger and the inlet of the compressor.

5. A liquid temperature control method, characterized in that: Using a liquid temperature control unit as claimed in claim 4, the method comprises: During refrigeration operation, one pipeline between the compressor and the condenser is connected, and the other pipeline outputted from the compressor is closed. Then, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas and outputs it to the condenser for cooling. Then, the gaseous refrigerant passes through the control valve and the throttling mechanism in sequence and enters the heat exchanger to cool the coolant passing through the heat exchanger. The cooled coolant flows out through the second outlet, and the refrigerant flows out through the first outlet and returns to the compressor again. During heating operation, one pipeline between the compressor and the condenser is closed, and the other pipeline of the compressor output is opened. Then, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas and then flows to the throttling mechanism. After entering the heat exchanger, it exchanges heat with the coolant flowing through the heat exchanger. The refrigerant after the heat exchange returns to the compressor again, and the heated coolant flows out through the second outlet.

6. A liquid temperature control method according to claim 5, characterized in that: During cooling operation, the following steps are included: S1.

1. According to a refrigeration request, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous state, and then the refrigerant flows into the condenser through the valve assembly and becomes a medium-temperature and high-pressure liquid state after being cooled in the condenser; S1.2, medium-temperature and high-pressure liquid refrigerant passes through the control valve and throttling mechanism in sequence; S1.

3. The low-temperature and low-pressure gas-liquid mixed refrigerant flowing out of the throttling mechanism enters the heat exchanger for evaporation and heat absorption, and the coolant flowing through the heat exchanger is cooled and flows out through the second outlet. At this time, the refrigerant is completely evaporated into a gaseous state in the heat exchanger and returns to the compressor again, repeating step S1.1 to continue the cycle for refrigeration.

7. A liquid temperature control method according to claim 5, characterized in that: During heating operation, the following steps are included: S2.

1. According to a heating request, the compressor compresses the gaseous refrigerant into a high-temperature and high-pressure gas, and then the refrigerant flows to the throttling mechanism through the valve assembly; S2.2, the high-temperature and high-pressure gaseous refrigerant is depressurized by the throttling mechanism into a high-temperature and low-pressure gaseous refrigerant and then enters the heat exchanger; S2.3, the high-temperature and low-pressure gaseous refrigerant exchanges heat with the coolant flowing through the heat exchanger in the heat exchanger, and the high-temperature and low-pressure gaseous refrigerant heats the coolant, and the heated coolant flows out through the second outlet. At the same time, the refrigerant becomes a low-temperature and low-pressure gaseous refrigerant, and then returns to the compressor again, and repeats step S2.1 to continue the cycle for heating.

8. A liquid temperature control method according to claim 5, characterized in that: The saturation temperature of the refrigerant entering the heat exchanger is lower than the temperature of the secondary refrigerant flowing through the heat exchanger.

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