Liquid temperature control unit

Abstract

The utility model provides a liquid temperature control unit which is not influenced by the external environment temperature, can ensure the constant heating performance of a secondary refrigerant, and ensures the normal use of the secondary refrigerant. 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] This utility model relates to the field of liquid temperature control technology, specifically to a liquid temperature control unit. Background Technology

[0002] In air conditioning engineering, industrial production, and scientific experiments, refrigeration devices are often used to indirectly cool the object being cooled, or to transport the cooling capacity generated by the refrigeration device over long distances. In these cases, an intermediate substance is required to be cooled in the evaporator before being used to cool the object being cooled. This intermediate substance is called a refrigerant.

[0003] Conventional refrigerant liquid temperature control units, with compressors at their core, typically cool the refrigerant liquid (such as water, ethylene glycol solution, or oil) using the compressor's cooling operation. When heating, the refrigerant liquid is usually heated by connecting an electric heater in series in the refrigerant liquid pipeline; that is, the refrigerant liquid is heated by turning on the electric heater. Alternatively, a heat pump (reverse Carnot cycle) can be used to heat the refrigerant liquid. However, these temperature control methods have the following drawbacks:

[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 heater is relatively high when it is working, and the refrigerant is prone to generate bubbles on the surface of the heater, which will affect the normal life of the refrigerant. In addition, the generated bubbles may cause cavitation on the surface of the high-speed rotating impeller of the pump that drives the flow of refrigerant.

[0005] 2. When heating is achieved through heat pump operation (reverse Carnot cycle), its heating capacity is affected by the ambient temperature. For example, when the ambient temperature is low, the evaporator in the heat pump cycle system will frost over. Once the evaporator frosts over, defrosting is required. However, regardless of 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] To address the aforementioned issues, this invention provides a liquid temperature control unit that is unaffected by external ambient temperature, ensuring constant heating performance of the refrigerant and guaranteeing its normal operation.

[0007] This utility model adopts the following technical solution: a liquid temperature control unit, including a refrigerant system and a secondary refrigerant system, with a heat exchanger connected between the refrigerant system and the secondary refrigerant system. 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. The secondary refrigerant system includes a water pump. The liquid inlet of the secondary refrigerant 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 connected to the control valve. The outlet of the throttling mechanism is connected to the first inlet. 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. 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.

[0009] Furthermore, the valve assembly uses a three-way valve. The compressor's output after compressing the refrigerant is divided into two paths after being connected 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 through the other outlet of the three-way valve.

[0010] Furthermore, a pressure sensor is installed on the connecting pipe between the first outlet of the heat exchanger and the inlet of the compressor.

[0011] The beneficial effects of this invention are that it allows the refrigerant to carry the heat generated by the compressor's own power consumption during operation into the heat exchanger to heat the flowing refrigerant liquid. Since the refrigerant does not undergo a phase change heat absorption process, there is no defrosting process, which does not affect the temperature fluctuation during heating. The heating capacity is not affected by the external ambient temperature, and it can ensure that the refrigerant can be continuously heated under different ambient temperatures. This ensures the constant heating performance of the refrigerant and guarantees its normal use, thus having good economic value. Attached Figure Description

[0012] Figure 1 This is a connection diagram of Embodiment 1 of this utility model;

[0013] Figure 2 This is a connection diagram of Embodiment 2 of this utility model. Detailed Implementation

[0014] Example 1

[0015] like Figure 1 As shown, this utility model discloses a liquid temperature control unit, including a refrigerant system and a secondary refrigerant system. A heat exchanger 1 connects the refrigerant system and the secondary refrigerant system. 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. The condenser 3 is equipped with a condensing fan 6. The secondary refrigerant system includes a water pump 7. The liquid inlet 12 of the secondary refrigerant 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. The outlet of the throttling mechanism 5 is connected to the first inlet. The compressor 2 compresses the refrigerant and then splits the output 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.

[0016] The valve assembly includes a first solenoid valve 8 and a second solenoid valve 9. The compressor 2 divides the output of the refrigerant after compression into two paths. One path enters the condenser 3 after passing through the first solenoid valve 8, and the other path is connected to the connecting pipeline between the check valve 4 and the throttling mechanism 5 after passing through the second solenoid valve 9. In the first embodiment, the control valve is the check valve 4.

[0017] To prevent the high-temperature, low-pressure gaseous refrigerant entering heat exchanger 1 from condensing into liquid inside heat exchanger 1, a pressure sensor P1 is installed on the connecting pipe between the first outlet of heat exchanger 1 and the inlet of compressor 2. The pressure value detected by pressure sensor P1 can directly obtain the corresponding refrigerant saturation point temperature (condensation point temperature). The method of obtaining the refrigerant saturation temperature by pressure value is an existing method, and the corresponding saturation temperature can be obtained by directly referring to the existing table parameters by the pressure value.

[0018] 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 heat transfer fluid 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 will still be in a gaseous state, thus ensuring the operational reliability of the compressor 2.

[0019] Example 2

[0020] like Figure 2 As shown, the valve assembly uses a three-way valve 10. The output of the compressor 2 after compressing the refrigerant is divided into two paths after being connected to the three-way valve 10. One path enters the condenser 3 through one of the outlets 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 through the other outlet of the three-way valve 10.

[0021] In Example 2, the control valve uses a solenoid valve 11, which opens or closes the refrigerant flow path by switching the solenoid valve 11 on and off.

[0022] By adopting the structure of Embodiment 1 or Embodiment 2, this utility model also provides a liquid temperature control method using a liquid temperature control unit, including:

[0023] During refrigeration operation, one pipeline between compressor 2 and condenser 3 is opened, and the other pipeline output by compressor 2 is closed. Then, compressor 2 compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous state and outputs it to condenser 3 for cooling. After passing through control valve and throttling mechanism 5, it enters heat exchanger 1 to cool the refrigerant flowing through heat exchanger 1. The cooled refrigerant flows out through the second outlet, and the refrigerant flows out through the first outlet and returns to compressor 2.

[0024] Specifically, during refrigeration operation, the following steps are included:

[0025] S1.1 According to the refrigeration request, the compressor 2 compresses the gaseous low-pressure and low-temperature refrigerant into a high-temperature and high-pressure gaseous state. Then, the refrigerant flows into the condenser 3 for cooling through the valve assembly (that is, at this time, the first solenoid valve 8 is open and the second solenoid valve 9 is closed; or one of the outlets of the three-way valve 10 connected to the condenser 3 is opened and the other outlet is closed). The heat is carried away by the air circulating through the condenser fan 6. After being cooled in the condenser 3, the refrigerant becomes a medium-temperature and high-pressure liquid refrigerant.

[0026] 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.

[0027] S1.3 The low-temperature, low-pressure gas-liquid mixture refrigerant flowing out from the throttling mechanism 5 enters the heat exchanger 1 for evaporation and heat absorption. The refrigerant flowing through the heat exchanger 1 is cooled down 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. Step S1.1 is repeated to continue the refrigeration cycle.

[0028] When heating is running, one pipeline between compressor 2 and condenser 3 is closed, and the other pipeline output from compressor 2 is opened. Then compressor 2 compresses the gaseous refrigerant into a high-temperature and high-pressure gaseous state and flows to the throttling mechanism 5. After entering the heat exchanger 1, it exchanges heat with the refrigerant flowing through the heat exchanger 1. The refrigerant after heat exchange returns to compressor 2, and the heated refrigerant flows out through the second outlet.

[0029] Specifically, during heating operation, the following steps are included:

[0030] 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 during operation, and becomes a high-temperature and high-pressure gaseous state. Then the refrigerant flows through the valve assembly (that is, at this time, the first solenoid valve 8 is closed and the second solenoid valve 9 is open; or one of the outlets of the three-way valve 10 connected to the condenser 3 is closed and the other outlet is opened) to the pipeline where the throttling mechanism 5 is located. The pipeline connected to the condenser 3 is blocked by the control valve.

[0031] S2.2. The high-temperature and high-pressure gaseous refrigerant is throttled and depressurized by the throttling mechanism 5 into a high-temperature and low-pressure gaseous refrigerant before entering the heat exchanger 1.

[0032] S2.3. The high-temperature, low-pressure gaseous refrigerant exchanges heat with the refrigerant flowing through the heat exchanger 1. The high-temperature, low-pressure gaseous refrigerant heats up the refrigerant. The heated refrigerant flows out through the second outlet, and at the same time, the refrigerant becomes a low-temperature, low-pressure gaseous refrigerant. Then it returns to the compressor 2 and repeats step S2.1 to continue the cycle of heating.

[0033] When the present invention is in heating mode, the high-temperature and high-pressure refrigerant exits from the compressor 2 and is throttled and depressurized by the throttling mechanism 5, turning the gaseous refrigerant into a high-temperature and low-pressure refrigerant. The high-temperature and low-pressure refrigerant is then introduced into the heat exchanger 1 to heat the flowing liquid refrigerant. At the same time, the refrigerant entering the heat exchanger 1 is in a low-pressure state, which avoids the refrigerant from condensing into liquid in the heat exchanger 1 (condensed refrigerant entering the compressor 2 would damage the compressor 2). The heat of the refrigerant comes from the working power consumption of the compressor 2 itself. Since there is no phase change heat absorption process for the refrigerant, there is no defrosting. In this mode, the heating capacity is not affected by the external ambient temperature, which ensures that the liquid refrigerant can be continuously heated under various ambient temperature conditions. 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.

[0034] 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 flowing liquid. There is no defrosting process, so it does not affect the temperature fluctuations during heating operation and is not affected by the external ambient temperature, resulting in a continuous and stable heating capacity. In addition, the compressor 2 can be a variable frequency compressor 2, which can adjust the heating capacity in multiple stages, making the liquid temperature rise more stable. Furthermore, using a variable frequency compressor 2 allows for a soft start during heating, avoiding a large inrush current (existing electric heaters generate a large starting inrush current).

[0035] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0036] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A liquid temperature control unit, comprising a refrigerant system and a secondary refrigerant system, characterized in that: A heat exchanger connects the refrigerant system and the secondary refrigerant system. 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. The secondary refrigerant system includes a water pump. The liquid inlet of the secondary refrigerant system is connected to the second inlet via 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 via the control valve. The outlet of the throttling mechanism is connected to the first inlet. The compressor outputs the compressed refrigerant, which is then split into two paths via 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. A pressure sensor is installed on the connecting pipeline between the first outlet of the heat exchanger and the inlet of the compressor.

2. The 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. The liquid temperature control unit according to claim 1, characterized in that: The valve assembly uses a three-way valve. The compressor's output after compressing the refrigerant is divided into two paths after being connected 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 through the other outlet of the three-way valve.

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