Heat pump device capable of simultaneously heating and defrosting

Abstract

The utility model discloses a heat pump device capable of simultaneously heating and defrosting. The heat pump device consists of an inner evaporator system and an outer evaporator system, the inner side evaporator system is connected with a gas-liquid separator, a compressor, an electric control valve, a condenser, a liquid storage tank, a filter, an economizer, an electronic expansion valve and an inner side system inlet; the outer side evaporator system is connected with a first electromagnetic valve, a gas-liquid separator, a compressor, an electric control valve, a condenser, a liquid storage tank, a filter, an economizer, an electronic expansion valve and a one-way valve and then is connected with an inlet of the outer side system. When the unit is defrosted, the tail end temperature is stable, a four-way valve can be omitted for a single heating unit, the structure is simple, the effect is remarkable, and the unit is suitable for extremely cold working conditions.

Description

Technical Field

[0001] This utility model relates to the field of air source heat pump technology, specifically a heat pump device that can simultaneously heat and defrost. Background Technology

[0002] Air source heat pumps extract heat energy from the air for heating or cooling. They eliminate the reliance on fossil fuels in traditional heating and cooling methods, achieving low-impact utilization of natural resources through a thermodynamic cycle. Specifically, this technology is based on the reverse Carnot cycle principle, using the coordinated operation of components such as the evaporator, compressor, condenser, and expansion valve to convert low-grade heat energy in the air into high-grade heat energy, meeting people's needs for indoor temperature regulation.

[0003] Frosting and defrosting issues on the outdoor evaporator of an air source heat pump lead to unstable operation and poor reliability. Air source heat pumps are most prone to frost formation on the surface of their outdoor heat exchangers when operating in weather conditions between -5℃ and 5℃ with relative humidity above 70%. Once frost forms on the outdoor heat exchanger, the frost layer thickens, increasing thermal resistance and airflow resistance, thus reducing heating capacity and the unit's COP, resulting in energy waste.

[0004] Reverse cycle defrosting is currently the most common defrosting method. It works by using a four-way reversing valve to change the refrigerant flow, converting the heating process into a cooling process. During defrosting, superheated refrigerant vapor discharged from the compressor is sent to the outdoor coil for defrosting. Once defrosting is complete, the heat pump reverses its operation again, resuming heating.

[0005] Reverse circulation defrosting will affect the water supply of the air source heat pump water heater. During the defrosting period, it will be unable to provide users with hot water at an effective temperature. At the same time, the original hot water temperature will drop after defrosting. From an energy perspective, the loss of this defrosting process is equivalent to twice the downtime of defrosting. Furthermore, the frequent switching of the four-way valve will affect its reliability and lifespan. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a heat pump device that simultaneously heats and defrosts, thereby solving the problems mentioned in the background art.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A heat pump device that simultaneously heats and defrosts mainly includes an evaporator, a compressor, a condenser, and an expansion valve. The evaporator is a finned three-layer copper tube structure, with the inner two layers forming an inner evaporator system and the outer layer forming an outer evaporator system. The inner system outlet of the inner evaporator system is sequentially connected to a gas-liquid separator, a compressor, an electric regulating valve, a condenser, a liquid receiver, a filter, an economizer, an electronic expansion valve, and the inner system inlet to form a loop. The outer system outlet of the outer evaporator system is sequentially connected to a first solenoid valve, a gas-liquid separator, a compressor, an electric regulating valve, a condenser, a liquid receiver, a filter, an economizer, an electronic expansion valve, a check valve, and then to the outer system inlet to form a loop. A bypass is provided at the compressor outlet, which is connected to the outer system inlet via a second solenoid valve. The outer system outlet pipe is connected to the condenser inlet via a third solenoid valve and to the liquid receiver inlet via a fourth solenoid valve. A temperature sensor is located near the outer system outlet.

[0009] The one-way valve is connected to the connecting pipe between the inner system inlet and the outer system inlet, with the direction from the inner system inlet to the outer system inlet.

[0010] Compared with existing technologies, this utility model has the following beneficial effects:

[0011] 1. This utility model can eliminate the need to absorb heat from the indoor heat dissipation terminal during unit defrosting, thus solving the problem of temperature fluctuation caused by the need to absorb heat from the indoor heat dissipation terminal during traditional defrosting.

[0012] 2. When the unit adopts single warm-up, this utility model can eliminate the four-way valve, reduce production costs, reduce unit failures caused by frequent reversals, and keep the electronic expansion valve in positive expansion without reverse expansion due to changes in refrigerant flow. This increases the service life of the expansion valve and also facilitates precise control of the opening.

[0013] 3. This invention employs a method of transferring heat from the outer evaporator system to the inner evaporator system during defrosting. This not only stabilizes the temperature at the terminal point but also allows the inner evaporator system to absorb some of the heat released by the outer evaporator system, reducing overall system heat loss and achieving energy savings. Furthermore, this feature allows for the appropriate activation of this mode to maintain normal operation of the entire unit when it is unable to operate normally in extremely cold environments.

[0014] 4. During defrosting, the refrigerant temperature in the outer evaporator system gradually increases. When the temperature sensor near the outlet of the outer system transmits a value higher than the outlet water temperature of the condenser, the central control system controls the unit to open the third solenoid valve and close the fourth solenoid valve, allowing the refrigerant to flow into the condenser to continue heat exchange, thereby better reducing the heat loss of the system and improving the system thermal efficiency. Attached Figure Description

[0015] Figure 1 This is a system schematic diagram of the present invention;

[0016] Figure 2 This is a three-dimensional structural diagram of the finned evaporator of this utility model;

[0017] Figure 3 This is a left view of the finned evaporator of this utility model;

[0018] Figure 4 This is a right view of the finned evaporator of this utility model;

[0019] Reference numerals: 1. Compressor; 2. Electronic expansion valve; 3. Check valve; 4. Evaporator; 5. Gas-liquid separator; 6. First solenoid valve; 7. Second solenoid valve; 8. Electric regulating valve; 9. Third solenoid valve; 10. Fourth solenoid valve; 11. Condenser; 12. Liquid receiver; 13. Filter; 14. Economizer; 15. Enthalpy-increasing electronic expansion valve; 41. Inner system inlet; 42. Inner system outlet; 43. Outer system inlet; 44. Outer system outlet; 45. Temperature sensor; 46. Inner evaporator system; 47. Outer evaporator system. Detailed Implementation

[0020] The technical solutions of the present invention will now be described in a comprehensive, detailed and clear manner with reference to the accompanying drawings of the embodiments of the present invention.

[0021] See appendix Figure 1-4As shown, a heat pump device that simultaneously heats and defrosts mainly includes an evaporator, a compressor, a condenser, and an expansion valve. The evaporator 4 is a finned three-layer copper tube structure, with the inner two layers forming an inner evaporator system 46 and the outer layer forming an outer evaporator system 47. The inner system outlet 42 of the inner evaporator system 46 is sequentially connected to a gas-liquid separator 5, a compressor 1, an electric regulating valve 8, a condenser 11, a liquid storage tank 12, a filter 13, an economizer 14, an electronic expansion valve 2, and an inner system inlet 41 to form a circulation. The outer system outlet 41 of the outer evaporator system 47... The system outlet 44 is sequentially connected to the first solenoid valve 6, gas-liquid separator 5, compressor 1, electric regulating valve 8, condenser 11, liquid storage tank 12, filter 13, economizer 14, electronic expansion valve 2, and check valve 3, and then connected to the outer system inlet 43 to form a loop; a bypass is provided at the outlet of the compressor 1, which is connected to the outer system inlet 43 through the second solenoid valve 7; the pipeline of the outer system outlet 44 is connected to the inlet of the condenser 11 through the third solenoid valve 9, and the fourth solenoid valve 10 is connected to the inlet of the liquid storage tank 12; a temperature sensor 45 is provided near the outer system outlet 44.

[0022] The one-way valve 3 is connected to the connecting pipe between the inner system inlet 41 and the outer system inlet 43, with the direction from the inner system inlet 41 to the outer system inlet 43.

[0023] The working process of this utility model is as follows: When the unit is operating normally in heating mode, its central control system calculates and uses a proportional-integral-derivative (PID) law to control the first solenoid valve 6 to be in the open state, the electric regulating valve 8 to be in the fully open state, and the second solenoid valve 7, the third solenoid valve 9, and the fourth solenoid valve 10 to be in the closed state. The compressor 1 generates high-temperature and high-pressure gaseous refrigerant, which flows through the electric regulating valve 8 and enters the condenser 11 to exchange heat with the medium at the end of use. After the heat exchange is completed, the medium-temperature and high-pressure gas-liquid mixed refrigerant enters the liquid storage tank 12. The liquid refrigerant flowing out of the liquid storage tank 12 enters the filter 13 for filtration and then enters the economizer 14. If the ambient temperature is below 10°C, the unit's enthalpy-increasing electronic expansion valve 15 opens and operates. At this time, the medium-temperature and high-pressure liquid refrigerant in the economizer cross-exchanges heat with the low-temperature and low-pressure gaseous refrigerant that has expanded after the enthalpy-increasing electronic expansion valve 15. After the heat exchange, the gaseous refrigerant enters the condenser 14. Compressor 1 replenishes gas to increase enthalpy. If the ambient temperature is higher than 10℃, and the ambient temperature condition is not met to open the electronic expansion valve 15 for increasing enthalpy, the medium-temperature high-pressure liquid refrigerant flows directly through the economizer without heat exchange. The main refrigerant flows out of the economizer 14 and enters the electronic expansion valve 2 for expansion. The expanded low-temperature, low-pressure gaseous refrigerant is divided into two paths and enters the evaporator 4. One path enters the inner evaporator system through the inner system inlet 41 to absorb heat from the air, while the other path enters the outer evaporator system through the outer system inlet 43 after passing through the one-way valve 3 to absorb heat from the air. After absorbing heat, the refrigerant in the inner evaporator system enters the gas-liquid separator 5 through the inner system outlet 42, while the refrigerant in the outer evaporator system enters the gas-liquid separator 5 through the first solenoid valve 6 after passing through the outer system outlet 44. Finally, the low-temperature, low-pressure gaseous refrigerant after passing through the gas-liquid separator 5 enters the compressor 1 to complete one cycle.

[0024] When the unit detects the need for defrosting, the central control system opens the second solenoid valve 7, while the electric regulating valve 8 closes at a set ratio of 70%-75%, and the fourth solenoid valve 10 opens, while the first solenoid valve 6 and the third solenoid valve 9 remain closed. At this time, the high-temperature, high-pressure gaseous refrigerant generated by the compressor 1 splits into two paths. One path passes through the electric regulating valve 8 into the condenser 11 for further heat exchange, completing the main cycle. The other path passes through the second solenoid valve 7 into the outer evaporator system to release heat and melt the frost on the outer evaporator system. Because the refrigerant pressure at the outer system inlet 43 is higher than the refrigerant pressure at the inner system inlet 41, the one-way valve 3 remains closed. As defrosting proceeds, the refrigerant temperature in the outer evaporator system gradually rises. As defrosting continues, the frost on the outer evaporator system is removed first. At this time, the inner evaporator system is drawn in by the fan and absorbs the heat released by the outer evaporator system, thereby melting and removing the frost. When the temperature sensor 45 near the outlet 44 of the outer system transmits a value higher than the outlet water temperature of the condenser 11, such as above 40°C, the central control system controls the unit to open the third solenoid valve 9 and close the fourth solenoid valve 10, allowing the refrigerant to flow into the condenser 11 to continue heat exchange, so as to better reduce the heat loss of the system. When the unit detects that defrosting is completed, all valves return to the above-mentioned common heating state and continue to operate in heating mode.

[0025] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the protection scope of the present utility model.

Claims

1. A heat pump device that simultaneously heats and defrosts, mainly comprising an evaporator, a compressor, a condenser, and an expansion valve, characterized in that, The evaporator (4) is a finned three-layer copper tube evaporator structure, wherein the inner two layers constitute the inner evaporator system (46), and the outer layer constitutes the outer evaporator system (47); the inner system outlet (42) of the inner evaporator system (46) is sequentially connected to the gas-liquid separator (5), compressor (1), electric regulating valve (8), condenser (11), liquid storage tank (12), filter (13), economizer (14), electronic expansion valve (2), and inner system inlet (41) to form a loop; the outer system outlet (44) of the outer evaporator system (47) is sequentially connected to the first solenoid valve (6), gas-liquid separator (5), compressor (1), electric regulating valve (8), condenser (11), liquid storage tank (12), filter (13), economizer (14), electronic expansion valve (2), and inner system inlet (41) to form a loop; 5) The compressor (1), electric regulating valve (8), condenser (11), liquid storage tank (12), filter (13), economizer (14), electronic expansion valve (2), check valve (3) and external system inlet (43) are connected to form a loop; a bypass is provided at the outlet of the compressor (1), which is connected to the external system inlet (43) through the second solenoid valve (7); the external system outlet (44) is connected to the condenser (11) inlet through the third solenoid valve (9), and the fourth solenoid valve (10) is connected to the liquid storage tank (12) inlet through the third solenoid valve (9); a temperature sensor (45) is provided near the external system outlet (44).

2. The heat pump device that simultaneously heats and defrosts according to claim 1, characterized in that: The one-way valve (3) is connected to the connecting pipe between the inner system inlet (41) and the outer system inlet (43), with the direction from the inner system inlet (41) to the outer system inlet (43).

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