Solar energy-air energy composite heat pump system based on self-contained energy storage cascade application and control method

Abstract

The invention provides a solar energy-air energy composite heat pump system based on self-contained energy storage cascade application and a control method. The solar energy-air energy composite heat pump system comprises a heat pump host module, a solar module and a hydraulic module. Hot water generated by the solar heat collector is accumulated in the energy storage water tank and serves as an external heat source for active enhanced vapor injection to improve the performance of the heat pump. An active enhanced vapor injection device is designed for a heat pump host module, a refrigerant in an economizer absorbs heat of heat storage hot water, is jetted to a middle pressure cavity of a compressor and is converted into heating capacity, and the performance of the heat pump is greatly improved. When it is detected that the temperature in the heat storage water tank is reduced to a certain temperature, the flow direction of the heat storage hot water is switched through the switching assembly, the heat storage hot water is pumped to the heat pump fluorine-water heat exchanger for heat exchange, the heat pump performance is improved, and cascade application of the heat storage hot water is achieved. Refrigerant flows in the fin type heat exchanger and the fluorine-water heat exchanger are controlled by respective electronic expansion valves, and the opening degrees of the fin type heat exchanger and the fluorine-water heat exchanger are adjusted according to respective air suction superheat degrees, so that respective optimal heat exchange effects are realized.

Description

Technical Field

[0001] The present invention relates to a solar-air composite heat pump system, and more specifically, to a solar-air composite heat pump system and a control method based on self-sufficient energy storage cascade application. Background Art

[0002] An air source heat pump is a heating device that converts electric energy and air energy into heat by the work of a compressor, achieving the complementarity of electric energy and air energy to generate heating capacity. However, in a low-temperature environment, the heating capacity and energy efficiency decay severely, and it cannot be used in an extremely low-temperature environment. The solutions mainly include solar-assisted air source heat pump technology and jet enthalpy-increasing technology.

[0003] In view of the intermittency of solar energy and the working characteristics of the heat pump, combining solar energy with the heat pump to form a combined cooling, heating and power supply system can achieve multi-energy complementarity. Currently, it is more common to use a solar heat absorption plate as an evaporator to absorb solar energy and increase the evaporation temperature, thereby increasing the heating capacity and energy efficiency. From the perspective of application types, it includes direct expansion type, indirect expansion type and composite type, with obvious energy-saving effects, but it cannot be used for refrigeration, only for heating. If a refrigeration function is to be achieved, 2 evaporators need to be designed on the system, and a finned evaporator is used for refrigeration.

[0004] To improve the performance of the heat pump, currently the most common is to adopt jet enthalpy-increasing technology. Due to its simple structure and low additional cost, it has been commercially applied. Active jet enthalpy increase can utilize an external heat source to improve the performance of the heat pump. However, when the heat of the heat storage hot water is gradually absorbed and utilized, the water temperature continuously decreases, and the effect of active jet enthalpy increase declines. Summary of the Invention

[0005] In view of this, in order to overcome the above technical defects, the present invention proposes a solar-air composite heat pump based on self-sufficient energy storage cascade application. The hot water generated by the solar collector is stored in the energy storage device. When the heat pump operates for heating, the heat storage hot water is pumped to the economizer of the heat pump for active jet enthalpy increase, and the refrigerant is sprayed to convert the heat storage heat into heating capacity in the form of jet enthalpy difference. When it is detected that the temperature in the heat storage water tank drops to a certain temperature, the flow direction of the heat storage hot water is switched by using a switching component and pumped to the fluorine-water heat exchanger on the evaporation side of the heat pump. The refrigerant and the hot water exchange heat to absorb the heat of the heat storage hot water to improve the performance of the heat pump and realize the cascade application of the heat storage hot water. The refrigerant flow rates in the fin heat exchanger and the fluorine-water heat exchanger are controlled by their respective electronic expansion valves, and their opening degrees are adjusted according to their respective suction superheat degrees to achieve their respective optimal heat exchange effects.

[0006] In order to solve the above technical problems, the technical solution of the present invention is: A solar-air composite heat pump system based on the cascaded application of self - contained energy storage, comprising a heat pump host module, a solar module and a hydraulic module connected by pipelines. The heat pump host module includes a fin heat exchanger, a fluorine - water heat exchanger, an active jet - enhanced economizer and a conversion component. The solar module is used to convert solar energy into heat energy and store it in a hot water storage tank; The operating states of the heat pump host module include a fin heat exchange state and a fin heat exchange + fluorine - water heat exchange state; When the heat pump host module is in the fin heat exchange state and the active jet - enhanced opening condition is met, the conversion component connects the hot water storage tank and the active jet - enhanced economizer, and the hot water in the hot water storage tank serves as the external heat source of the active jet - enhanced economizer; when the active jet - enhanced opening condition is not met, only the conventional heating operation of fin heat exchange is carried out.

[0007] When the heat pump host module is in the fin heat exchange + fluorine - water heat exchange state, the fluorine - water heat exchanger is in parallel with the fin heat exchanger. On the one hand, the refrigerant in the fin heat exchanger exchanges heat with air to absorb air energy. On the other hand, the conversion component connects the hot water storage tank and the fluorine - water heat exchanger, and conveys the hot water in the hot water storage tank to the fluorine - water heat exchanger to absorb the heat of the stored - heat hot water.

[0008] Furthermore, the active jet - enhanced economizer includes an active injection inlet pipe and an active injection outlet pipe, which are respectively connected to the water outlet and water return port of the hot water storage tank of the solar module. The conversion component includes an injection inlet three - way valve and an injection outlet three - way valve. The injection inlet three - way valve includes interfaces a1, b1 and c1. The injection inlet three - way valve is connected to the water outlet of the hot water storage tank and the active injection inlet pipe through interfaces a1 and b1. The injection inlet three - way valve (54) is connected to the water outlet of the hot water storage tank and the water inlet of the fluorine - water heat exchanger through interfaces a1 and c1. The injection outlet three - way valve includes interfaces a2, b2 and c2. The injection outlet three - way valve is connected to the water inlet of the hot water storage tank and the active injection outlet pipe through interfaces a2 and b2. The injection inlet three - way valve is connected to the water inlet of the hot water storage tank and the water outlet of the fluorine - water heat exchanger through interfaces a2 and c2.

[0009] Furthermore, the heat pump host module includes a variable - frequency compressor, an oil separator, a four - way valve, a fin heat exchanger, a sub - cooled electronic expansion valve; The exhaust pipe of the variable-frequency compressor is connected to the d pipe of the four-way valve through an oil separator. The c pipe of the four-way valve is connected to one end of the fin heat exchanger. The e pipe of the four-way valve is connected to the air pipe of the hydraulic module. The s pipe of the four-way valve is connected to the inlet pipe of the gas-liquid separator. The outlet pipe of the gas-liquid separator is connected to the suction pipe of the variable-frequency compressor. The other end of the fin heat exchanger is connected to the main liquid pipe; The active jet enthalpy-increasing economizer is connected with an active injection branch pipe inlet, an active injection branch pipe outlet, an active injection water inlet pipe and an active injection water outlet pipe. Among them, the active injection branch pipe inlet is communicated with the main liquid pipe, and the active injection branch pipe outlet is connected to the intermediate pressure chamber connection pipe of the variable-frequency compressor.

[0010] Further, the solar energy module includes a solar collector, the hot water storage tank, and a solar hot water pump. A heat storage hot water inlet pipe and a heat storage hot water return pipe are connected between the hot water storage tank and the solar collector. The solar hot water pump is installed on the heat storage hot water return pipe.

[0011] Further, the heat pump host module includes a liquid storage tank, a liquid pipe stop valve and a gas pipe stop valve. The liquid pipe stop valve and the gas pipe stop valve are used to connect the hydraulic module. The gas pipe stop valve is connected to the e pipe of the four-way valve. The liquid pipe stop valve is connected to the liquid storage tank. The liquid storage tank is connected to one end of the fin heat exchanger. The hydraulic module includes a condenser, a buffer tank and a heating water pump. Among them, the gas pipe stop valve is connected to the gas pipe of the condenser. The liquid pipe stop valve is connected to the liquid pipe of the condenser. The heating water pump is connected to the outlet pipe of the condenser. The buffer tank is connected to the inlet pipe of the condenser.

[0012] Further, a temperature detection module is also included. The temperature detection module includes an outdoor ambient temperature sensor, an exhaust temperature sensor, a suction temperature sensor, a coil temperature sensor on the fin heat exchanger, a liquid pipe temperature sensor, a water tank temperature sensor, an active jet enthalpy-increasing temperature detection component, a fin heat exchanger inlet temperature sensor, and a fluorine-water heat exchanger inlet temperature sensor; The outdoor ambient temperature sensor is used to detect the outdoor ambient temperature T ao , the exhaust temperature sensor is used to detect the exhaust temperature T d , the suction temperature sensor is used to detect the suction temperature T s , the coil temperature sensor is used to detect the coil temperature T def , the liquid pipe temperature sensor is used to detect the liquid pipe temperature T liq0 , the water tank temperature sensor is used to detect the temperature T of the hot water storage tank tank , the fin heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fin heat exchangerliq1 , the outdoor water - fluorine heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fluorine - water heat exchanger liq2 .

[0013] A control method for a solar - air energy composite heat pump system based on self - contained energy storage cascade application, providing the solar - air energy composite heat pump system as described in any one of the above, the control method includes Step S1: Configure a preset fin - type heat exchange conventional heating operation start condition. When the fin - type heat exchange conventional heating operation start condition is met, start the fin - type heat exchange conventional heating operation control; Step S2A: Configure a preset active jet - enhanced enthalpy operation start condition. When the active jet - enhanced enthalpy operation start condition is met, start the active jet - enhanced enthalpy heating control; Step S2B: Configure a preset active jet - enhanced enthalpy operation stop condition. When the active jet - enhanced enthalpy operation stop condition is met, stop the active jet - enhanced enthalpy heating control; Step S3A: Configure a preset double - evaporator heating operation start condition. When the double - evaporator heating operation start condition is met, start the double - evaporator heating operation control; Step S3B: Configure a preset double - evaporator heating operation stop condition. When the double - evaporator heating operation stop condition is met, stop the double - evaporator heating operation control.

[0014] Further: In step S1, when the heat pump host module receives a heating start command and the return water temperature T w,in < the preset return water temperature threshold T w,in,set - the preset return water temperature hysteresis threshold δT w,in , it is regarded as meeting the fin - type heat exchange conventional heating operation start condition.

[0015] Further: In step S2A, when the unit starts the fin - type heat exchange conventional heating operation, when the exhaust gas temperature superheat ΔT d > the preset exhaust gas temperature superheat threshold ΔT d,set1 + the preset exhaust gas temperature superheat hysteresis threshold δT d , and the current water tank temperature T tank > the current liquid pipe temperature T liq0 + the preset start temperature hysteresis threshold δT liq0 , it is regarded as meeting the active jet - enhanced enthalpy heating operation start condition; In step S2B, when it is detected that the actual exhaust gas superheat ΔT d ≤ the preset second exhaust gas superheat threshold ΔT d,set2 - the exhaust gas superheat hysteresis threshold δTd When, or when detecting the inlet temperature T of the heat source side of the active jet enthalpy increase h,inj,in <Outlet temperature T of the refrigerant of the active jet enthalpy increase r,inj,out + Preset first temperature return difference threshold δT h,r,set Or the outlet temperature T of the heat source side of the active jet enthalpy increase h,inj,out <T r,inj,in + Preset second temperature return difference threshold δT h,r,set2 When, it is regarded as meeting the shutdown condition of the active jet enthalpy increase heating operation, and the conventional heating operation is carried out. After 5 minutes, the determination of step S2A is carried out again.

[0016] Furthermore: In step S3A, when the unit performs the conventional heating operation of the fin heat exchanger and does not meet the startup condition of the active jet enthalpy increase heating operation, and the water tank temperature T tank > Outdoor ambient temperature T ao + Preset ambient temperature return difference threshold δT ao When the sum is reached, it is regarded as meeting the startup condition of the double-evaporator heating operation; In step S3B, when the unit is in the heating operation, the water tank temperature T tank <Outdoor ambient temperature T ao , it is regarded as meeting the shutdown condition of the double-evaporator heating operation, and the conventional heating operation of the fin heat exchanger is carried out.

[0017] When the outdoor ambient temperature T ao ≤Water tank temperature T tank ≤Outdoor ambient temperature T ao + Preset ambient temperature return difference threshold δT ao , maintain the current operating state.

[0018] The technical effects of the present invention are mainly reflected in the following aspects: The solar collector absorbs solar energy and heats the hot water. The hot water that absorbs heat is stored in the energy storage water tank and used as an external heat source for the active jet enthalpy increase to improve the performance of the heat pump. For the heat pump subsystem, an active jet enthalpy increase device is designed. The refrigerant in the economizer absorbs the heat of the heat storage hot water and is converted into heating capacity, greatly improving the heating capacity and coefficient of performance of the heat pump, and solving the technical bottleneck that the heat pump cannot be applied in extremely low temperature environments; when it is detected that the temperature in the heat storage water tank drops to a certain temperature, the flow direction of the heat storage hot water is switched by using the switching component and pumped to the evaporation side of the heat pump to absorb the heat storage heat to improve the performance of the heat pump and realize the cascade application of the heat storage hot water. The refrigerant flow rates in the fin heat exchanger and the fluorine-water heat exchanger are controlled by their respective electronic expansion valves, and their opening degrees are adjusted according to their respective suction superheats to achieve their respective optimal heat exchange effects. Description of the Drawings

[0019] Figure 1: System schematic diagram of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application; Figure 2 : Schematic diagram of the system flow path of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application in the active jet enthalpy-increasing heating operation mode; Figure 3 : Schematic diagram of the system flow path of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application in the finned heat exchanger conventional heating operation mode; Figure 4 : Schematic diagram of the system flow path of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application in the double evaporator heating mode; Figure 5 : Schematic diagram of the distribution positions of the active jet enthalpy economizer and the active jet enthalpy temperature detection component; Figure 6 : Schematic flow chart of the control method of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application.

[0020] Reference numerals: 1. Variable frequency compressor; 2. High-pressure pressure sensor; 3. Oil separator; 4. Four-way valve; 5. Finned heat exchanger; 6. First main electronic expansion valve; 7. Liquid storage tank; 8. Liquid pipe stop valve; 9. Gas pipe stop valve; 10. Gas-liquid separator; 11. Subcooling electronic expansion valve; 12. Active jet enthalpy economizer; 13. Active injection branch inlet pipe; 14. Active injection branch outlet pipe; 21. Solar collector panel; 22. Solar hot water water pump; 31. Hot water storage tank; 32. Jet enthalpy hot water water pump; 33. Active injection inlet pipe; 34. Active injection outlet pipe; 35. Make-up water valve; 36. Drain valve; 41. Condenser; 42. Buffer tank; 43. Heating water pump; 51. Fluorine-water heat exchanger; 52. Second main electronic expansion valve; 54. Injection water three-way valve; 55. Injection water three-way valve. Detailed implementation manners

[0021] The following further details the specific implementation manners of the present invention in conjunction with the accompanying drawings, so that the technical solutions of the present invention are easier to understand and master.

[0022] Example: Refer to Figure 1 As shown, a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application includes a heat pump host module, a solar module, and a hydraulic module. The outdoor unit module includes a variable frequency compressor 1, an oil separator 3, a four-way valve 4, a finned heat exchanger 5, a main electronic expansion valve 6, an economizer with active jet enthalpy, and a subcooling electronic expansion valve 11.

[0023] The exhaust pipe of the variable-frequency compressor 1 is connected to the d pipe of the four-way valve 4 through the oil separator 3. The c pipe of the four-way valve 4 is connected to one end of the fin heat exchanger 5. The e pipe of the four-way valve 4 is connected to the air pipe of the hydraulic module. The s pipe of the four-way valve 4 is connected to the inlet pipe of the gas-liquid separator 10. The outlet pipe of the gas-liquid separator 10 is connected to the return air pipe of the variable-frequency compressor 1. The other end of the fin heat exchanger 5 is connected to the main liquid pipe.

[0024] The active jet enthalpy-increasing economizer 12 is connected with an active injection branch pipe inlet pipe 13, an active injection branch pipe outlet pipe 14, an active injection water inlet pipe 33 and an active injection water outlet pipe 34. Among them, the active injection branch pipe inlet pipe 13 is communicated with the main liquid pipe. The active injection branch pipe outlet pipe 14 is connected to the intermediate pressure chamber connection pipe of the variable-frequency compressor 1. The active injection water inlet pipe 33 and the active injection water outlet pipe 34 are respectively connected to the water outlet and water return ports of the heat storage water tank 31. A jet enthalpy-increasing hot water water pump 32 is installed on the active injection water inlet pipe 33. A heat storage hot water inlet pipe and a heat storage hot water return pipe are connected between the heat storage water tank 31 and the heat exchange flow path of the solar photovoltaic panel 21. A solar hot water water pump 22 is installed on the heat storage hot water return pipe for pumping cooling water to flow between the heat storage water tank 31 and the solar collector.

[0025] The heat pump main unit module includes a fin heat exchanger 5, a fluorine-water heat exchanger 51, an active jet enthalpy-increasing economizer 12 and a conversion component. The solar module is used to convert solar energy into heat energy and store it in the heat storage water tank 31; The heating heat exchange modes of the heat pump main unit module include a fin heat exchange mode and a fin heat exchange + fluorine-water heat exchange mode. When the heat pump main unit module is in the fin heat exchange mode, the conversion component connects the heat storage water tank 31 and the active jet enthalpy-increasing economizer 12. When the active jet enthalpy-increasing opening condition is met, the hot water in the heat storage water tank 31 serves as the external heat source of the active jet enthalpy-increasing economizer 12. When the active jet enthalpy-increasing opening condition is met, the conventional heating operation mode of fin heat exchange is carried out.

[0026] When the heat pump main unit module is in the fin heat exchange + fluorine-water heat exchange state, the fluorine-water heat exchanger 51 is connected in parallel with the fin heat exchanger 5, and the conversion component connects the heat storage water tank 31 and the fluorine-water heat exchanger 51 to transport the hot water in the heat storage water tank 31 to the fluorine-water heat exchanger 51 to absorb air energy.

[0027] The active jet enthalpy-increasing economizer 12 includes an active injection water inlet pipe 33 and an active injection water outlet pipe 34. The active injection water inlet pipe 33 and the active injection water outlet pipe 34 are respectively connected to the water outlet and water return ports of the heat storage water tank 31 of the solar module. The conversion component includes a jet injection water three-way valve 54 and a jet outlet water three-way valve 55. The injection water inlet three-way valve 54 includes an a1 interface, a b1 interface, and a c1 interface. The injection water inlet three-way valve 54 is connected to the water outlet of the hot water storage tank 31 and the active injection water inlet pipe 33 through the a1 interface and the b1 interface, and the injection water inlet three-way valve 54 is connected to the water outlet of the hot water storage tank 31 and the water inlet of the fluorine-water heat exchanger 51 through the a1 interface and the c1 interface. The injection water outlet three-way valve 55 includes an a2 interface, a b2 interface, and a c2 interface. The injection water outlet three-way valve 55 is connected to the water inlet of the hot water storage tank 31 and the active injection water outlet pipe 34 through the a2 interface and the b2 interface, and the injection water inlet three-way valve 54 is connected to the water inlet of the hot water storage tank 31 and the water outlet of the fluorine-water heat exchanger 51 through the a2 interface and the c2 interface.

[0028] The heat pump main unit module includes a liquid storage tank 7, a liquid pipe stop valve 8, and a gas pipe stop valve 9. The liquid pipe stop valve 8 and the gas pipe stop valve 9 are used to connect to the hydraulic module. The gas pipe stop valve 9 is connected to the c pipe of the four-way valve 4. The outlet pipe of the liquid pipe stop valve 8 is connected to the inlet pipe of the liquid storage tank 7, and the outlet pipe of the liquid storage tank 7 is connected to one end of the fin heat exchanger 5.

[0029] The hydraulic module includes a condenser 41, a buffer tank 42, and a heating water pump 43. Among them, the gas pipe stop valve 9 is connected to the gas pipe of the condenser 41, the liquid pipe stop valve 8 is connected to the liquid pipe of the condenser 41, the heating water pump 43 is connected to the outlet pipe of the condenser 41, and the buffer tank 42 is connected to the inlet pipe of the condenser 41.

[0030] The hot water storage tank 31 is connected with a make-up water valve 35 and a drain valve 36. The drain valve 36 is used for sewage discharge, and the make-up water valve 35 is used to supplement water into the hot water storage tank 31.

[0031] It further includes a temperature detection module. The temperature detection module includes an outdoor ambient temperature sensor, an exhaust temperature sensor, a suction temperature sensor, a coil temperature sensor on the fin heat exchanger 5, a liquid pipe temperature sensor, a water tank temperature sensor, a fin heat exchanger inlet temperature sensor, a fluorine-water heat exchanger inlet temperature sensor, and an active jet enthalpy increase temperature detection component. The outdoor ambient temperature sensor is used to detect the outdoor ambient temperature T ao , the exhaust temperature sensor is used to detect the exhaust temperature T d , the suction temperature sensor is used to detect the suction temperature T s , the coil temperature sensor is used to detect the coil temperature T def , the liquid pipe temperature sensor is used to detect the liquid pipe temperature T liq0 , the water tank temperature sensor is used to detect the temperature T of the hot water storage tank 31 tank, The fin heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fin heat exchanger 5 liq1 , the outdoor water-fluorine heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fluorine-water heat exchanger 51liq2 。

[0032] The active jet enthalpy-increasing temperature detection component includes a jet enthalpy-increasing water inlet temperature sensor, a jet enthalpy-increasing water outlet temperature sensor, a refrigerant injection inlet pipe temperature sensor, and a refrigerant injection outlet pipe temperature sensor. The refrigerant injection inlet pipe temperature sensor is used to detect the inlet temperature T of the active jet enthalpy-increasing refrigerant inj,in , and the refrigerant injection outlet pipe temperature sensor is used to detect the outlet temperature T of the active jet enthalpy-increasing refrigerant inj,out , the jet enthalpy-increasing water inlet temperature sensor is used to detect the inlet temperature T of the heat source side of the active jet enthalpy-increasing w,inj,in , and the jet enthalpy-increasing water outlet temperature sensor is used to detect the outlet temperature T of the heat source side of the active jet enthalpy-increasing w,inj,out 。

[0033] The hydraulic module includes a water inlet temperature sensor and a water outlet temperature sensor. The water inlet temperature sensor is used to detect the water inlet temperature T of the condenser w,in , and the water outlet temperature sensor is used to detect the water outlet temperature T of the condenser w,out 。

[0034] The heat pump system involved in this application has 4 operating modes, namely: 1) Refrigeration operation mode; 2) Active jet enthalpy-increasing heating operation mode; 3) Finned heat exchanger conventional heating mode; 4) Double evaporator heating mode.

[0035] 1) Refrigeration operation mode In the refrigeration operation mode, the fluorine-water heat exchanger does not participate in refrigeration operation.

[0036] 2) Active jet enthalpy-increasing heating operation mode In the active jet enthalpy-increasing heating operation mode, through the settings of the hot water storage tank 31 and the solar collector 21, solar energy is used for heat storage to generate hot water, which is stored in the hot water storage tank 31. In this mode, the a1 interface to the b1 interface direction of the injection water three-way valve 54 is conducted, and the a1 interface to the c1 interface direction is closed. The b2 interface to the a2 interface direction of the injection water three-way valve 55 is conducted, and the c2 to a2 interface direction is closed. The jet enthalpy-increasing hot water pump 32 pumps the heat storage hot water to circulate between the hot water storage tank 31 and the active jet enthalpy-increasing economizer 12. Refer to the flow path diagram Figure 2, the high-temperature gaseous refrigerant discharged from the variable-frequency compressor 1 enters the hydraulic module through the oil separator 3, the d pipe of the four-way valve 4, the c pipe of the four-way valve 4, and the gas pipe stop valve 9 for heat exchange. After releasing heat, the refrigerant passes through the liquid pipe stop valve 8 and the liquid storage tank 7, and then part of the refrigerant flows through the main liquid pipe: passes through the main electronic expansion valve 6, the fin heat exchanger 5, the c pipe of the four-way valve 4, the s pipe of the four-way valve 4, and returns to the variable-frequency compressor 1 after passing through the gas-liquid separator 10; the other part of the refrigerant passes through the sub-cooling electronic expansion valve 11 for throttling and then enters the active jet enthalpy economizer 12 through the active jet branch inlet pipe 13, exchanges heat with the hot water in the heat storage water tank, and then returns to the variable-frequency compressor 1 through the active jet branch outlet pipe 14.

[0037] 3) Finned heat exchange conventional heating mode In the conventional heating mode, the flow path diagram refers to Figure 3 , the high-temperature gaseous refrigerant discharged from the variable-frequency compressor 1 enters the hydraulic module through the oil separator 3, the d pipe of the four-way valve 4, the e pipe of the four-way valve 4, and the gas pipe stop valve 9 for heat exchange. After releasing heat, the refrigerant passes through the liquid pipe stop valve 8 and the liquid storage tank 7, and then passes through the main electronic expansion valve 6, the fin heat exchanger 5, the c pipe of the four-way valve 4, the s pipe of the four-way valve 4, and returns to the variable-frequency compressor 1 after passing through the gas-liquid separator 10.

[0038] 4) Dual evaporator heating mode The hot water in the heat storage water tank 31 gradually decreases in temperature as the active jet enthalpy increases. When the water tank temperature sensor detects that the hot water temperature in the water tank drops to a certain temperature, the active jet enthalpy effect decreases, and at this time, the working state of the heat pump main unit module switches to the dual evaporator heating mode. In the dual evaporator heating mode, the a1 interface to the c1 interface direction of the injection water three-way valve 54 is conducted, and the a1 interface to the b1 interface direction is closed. The c2 interface to the a2 interface direction of the injection water three-way valve 55 is conducted, and the b2 interface to the a2 interface direction is closed. The jet enthalpy hot water pump 32 pumps the heat storage hot water to circulate between the heat storage water tank 31 and the fluorine-water heat exchanger 51.

[0039] The flow path diagram refers to Figure 4The high-temperature gaseous refrigerant discharged from the variable-frequency compressor 1 enters the hydraulic module through the oil separator 3, the d pipe of the four-way valve 4, the e pipe of the four-way valve 4, and the gas pipe stop valve 9 for heat exchange. After the refrigerant releases heat, it passes through the liquid pipe stop valve 8 and the liquid storage tank 7, and then is divided into two paths after passing through the main liquid pipe and the main electronic expansion valve 6. One path passes through the first main electronic expansion valve 6 and the fin heat exchanger 5, and the other path passes through the second main electronic expansion valve 52 and the fluorine-water heat exchanger 51 and then converges. It then returns to the variable-frequency compressor 1 through the c pipe of the four-way valve 4, the s pipe of the four-way valve 4, and the gas-liquid separator 10. At this time, the jet-enhanced enthalpy hot water pump 32 pumps hot water and flows through the a1 interface and the c1 interface of the injection water three-way valve 54 to the fluorine-water heat exchanger 51. The refrigerant in the fluorine-water heat exchanger absorbs the heat of the heat storage hot water to improve the heat pump performance and realize the cascade application of the heat storage hot water, and then returns to the heat storage water tank 31 through the c2 interface and the a2 interface of the injection water three-way valve 55.

[0040] Please refer to Figure 6 A control method for a solar-air energy composite heat pump system based on the cascade application of self-sufficient energy storage, including Step S1: Configure a preset conventional heating operation start condition. When the conventional heating operation start condition is satisfied, start the conventional heating operation control; Step S2A: Configure a preset active jet-enhanced enthalpy operation start condition. When the active jet-enhanced enthalpy operation start condition is satisfied, start the active jet-enhanced enthalpy heating control; Step S2B: Configure a preset active jet-enhanced enthalpy operation stop condition. When the active jet-enhanced enthalpy operation stop condition is satisfied, stop the active jet-enhanced enthalpy heating control; Step S3A: Configure a preset dual-evaporator heating operation start condition. When the dual-evaporator heating operation start condition is satisfied, start the dual-evaporator heating operation control; Step S3B: Configure a preset dual-evaporator heating operation stop condition. When the dual-evaporator heating operation stop condition is satisfied, stop the dual-evaporator heating operation control.

[0041] The following describes the control content in detail according to the operation mode.

[0042] 1. Finned heat exchange conventional heating operation mode 1.1 Start condition The start condition for the finned heat exchange conventional heating operation includes: when receiving a heating start command and the return water temperature T w,in < the preset return water temperature T w,in,set - the preset return water temperature difference threshold δT w,in , the unit starts the heating operation.

[0043] 1.2 Control content When the unit starts and runs, the first main electronic expansion valve 6 opens to a certain initial opening. After running for t minutes, the opening is adjusted according to the suction superheat of the finned heat exchanger. Here, the suction superheat of the finned heat exchanger is defined as ΔT s1, =T s -T liq1 . When the actual suction superheat value ΔT s is greater than the target superheat ΔT s1,set plus the preset suction superheat deadband threshold δT s1 , the opening of the first main electronic expansion valve 6 increases. When the actual suction superheat value ΔT s is less than the target superheat ΔT s1set minus the suction superheat deadband threshold δT s1 , the opening of the first main electronic expansion valve 6 decreases.

[0044] When the actual suction superheat value ΔT s is between the target superheat ΔT s1,set minus the preset suction superheat deadband threshold δT s1 and ΔT s1,set plus the preset suction superheat deadband threshold δT s1 , the opening of the first main electronic expansion valve 6 remains unchanged at the current opening.

[0045] 2. Active jet enhanced enthalpy heating operation mode 2.1 Starting conditions The discharge superheat ΔT d is defined as the discharge temperature detected by the discharge temperature sensor minus the saturation temperature corresponding to the high-pressure detected by the high-pressure pressure sensor 2.

[0046] When the unit performs conventional finned heat exchange heating operation, and the current discharge superheat ΔT d is greater than the sum of the preset first discharge superheat ΔT d,set1 and the preset discharge superheat deadband threshold δT d , and the current water tank temperature T tank is greater than the sum of the current liquid pipe temperature T liq0 and the preset opening temperature deadband threshold δT liq0 , it is regarded as meeting the starting conditions for active jet enhanced enthalpy heating operation. That is: if it is detected that the current discharge superheat ΔT d > the preset first discharge superheat ΔT d,set1 + the preset discharge superheat deadband threshold δT d , and the current water tank temperature T tank > the current liquid pipe temperature T liq0 + the preset temperature deadband threshold δT liq0 , active jet enhanced enthalpy heating operation is started, and the corresponding subcooling electronic expansion valve 11 is opened, with an initial opening Vopen2 , using the hot water in the external hot water storage tank 31 as the heat source for the active jet enthalpy increase, the jet enthalpy increase hot water pump 21 is turned on, and the water flow rate is kept constant at Y m 3 / h.

[0047] 2.2 Control content The opening control strategy of the active jet enthalpy increase takes a certain superheat value of injection as the control target. The opening control strategy of the active jet enthalpy increase includes configuring a target superheat value of injection and a superheat return difference value. The superheat of injection ΔT inj is defined as the temperature T r,inj,out at the outlet of the injected refrigerant minus the temperature T r,inj,in at the inlet of the injected refrigerant.

[0048] After running for a preset set duration, when the current superheat of injection ΔT inj is greater than the sum of the preset target superheat threshold value T inj,set of injection and the preset superheat return difference threshold value δT inj , control the opening of the subcooling electronic expansion valve 11 to increase; that is: when the current actual superheat of injection ΔT inj > ΔT inj,set + superheat return difference value δT inj , the opening of the subcooling electronic expansion valve 11 increases; When the current superheat of injection ΔT inj is less than the difference between the target superheat value of injection ΔT inj,set and the superheat return difference threshold value δT inj , control the opening of the subcooling electronic expansion valve 11 to decrease; that is: when the actual superheat of injection ΔT inj < ΔT inj,set - superheat return difference threshold value δT inj , the opening of the subcooling electronic expansion valve 11 decreases; When the current superheat of injection ΔT inj is between the target superheat value of injection ΔT in,set and the difference between the preset superheat return difference threshold value δT inj and the sum of the target superheat value of injection and the preset superheat return difference threshold value, the opening of the subcooling electronic expansion valve 11 remains unchanged at the current opening. That is: when the set value ΔT inj,set - superheat return difference threshold value δT in ≤ actual superheat of injection ΔT inj ≤ ΔT inj,set + superheat return difference value δT inj , the subcooling electronic expansion valve 11 remains unchanged at the current opening.

[0049] 2.3 Closing conditions Closing of the active jet enthalpy increase: The active jet enthalpy increase shutdown condition configures a preset second exhaust superheat threshold ΔT d,set2 (ΔT d,set2 < ΔT d,set1 ), when the exhaust superheat ΔT d is less than the difference between the preset second exhaust superheat threshold ΔT d,set,2 and the preset exhaust superheat hysteresis threshold δT d , it is regarded as meeting the active jet enthalpy increase shutdown condition; that is: when the detected actual exhaust superheat ΔT d ≤ the preset exhaust superheat threshold ΔT d,set2 - δT d , the second subcooling electronic expansion valve closes 32, and the active jet enthalpy increase stops running.

[0050] The active jet enthalpy increase shutdown condition is also configured with a first temperature hysteresis threshold δT h,r,set1 and a second temperature hysteresis threshold δT h,r,set2 , when the inlet temperature T h,inj,in of the heat source side of the active jet enthalpy increase is less than the sum of the outlet temperature T r,inj,out of the refrigerant of the active jet enthalpy increase and the preset first temperature hysteresis threshold δT h,r,set1 , or when the outlet temperature T h,inj,out of the heat source side of the active jet enthalpy increase is less than the sum of the inlet temperature T r,inj,in of the refrigerant of the active jet enthalpy increase and the preset second temperature hysteresis threshold δT h,r,set2 , it is regarded as meeting the active jet enthalpy increase shutdown condition; that is: when it is detected that T h,inj,in < T r,inj,out + δT h,r,set1 or T h,inj,out < T r,inj,in + δT h,r,set2 , it is determined that the unit can no longer effectively utilize the external heat source to increase the heat production, and immediately close the jet enthalpy hot water pump 32, and adjust the opening of the subcooling electronic expansion valve 11 to 0 steps.

[0051] After the active jet enthalpy increase heating operation is shut down, the fin - type conventional heating operation is carried out, and the S2A determination is carried out again after 5 minutes.

[0052] 3. Dual - evaporator heating operation 3.1 Starting conditions The starting conditions for the dual - evaporator heating operation: The unit is in heating operation and meets the following conditions: It does not meet the above - mentioned starting conditions for the active jet enthalpy increase, and the water tank temperature T tank > the outdoor ambient temperature T ao + the preset ambient temperature hysteresis threshold δT ao .

[0053] 3.2 Control content When the outdoor ambient temperature T ao ≤ the water tank temperature T tank ≤ the outdoor ambient temperature T ao + the set ambient temperature hysteresis threshold δT ao , maintain the current heating operation. Here, the current heating operation refers to the dual-evaporator heating operation or the fin heat exchange conventional heating operation. For example, when in the fin heat exchange conventional heating operation and the above conditions are detected, maintain the fin heat exchange conventional heating operation; when in the dual-evaporator heating operation and the above conditions are detected, maintain the dual-evaporator heating operation.

[0054] The opening degrees of the first main electronic expansion valve 6 and the second main electronic expansion valve 52 are independently controlled.

[0055] Among them, the opening degree of the first main electronic expansion valve 6 is controlled according to the content of 2.2, and the second main electronic expansion valve 52 controls the opening degree according to its corresponding suction superheat.

[0056] The second main electronic expansion valve 52 is opened at a certain initial opening degree. After running for the initial running duration t minutes, the opening degree is adjusted according to the suction superheat corresponding to the fluorine-water heat exchanger 51, and the suction superheat target is ΔT s2,set =T s -T liq2 .

[0057] When the actual suction superheat value ΔT s is greater than the target suction superheat ΔT s2,setset + the preset suction superheat hysteresis threshold δT s2 , the opening degree of the second main electronic expansion valve 6 increases; When the actual suction superheat value ΔT s is less than the target suction superheat ΔT s2,setset - the preset suction superheat hysteresis threshold δT s2 , the opening degree of the second main electronic expansion valve 6 decreases; When the actual suction superheat value ΔT s is between the target suction superheat ΔT s2,setset - the preset suction superheat hysteresis threshold δT s2 and the target suction superheat ΔT s2,setset + the preset suction superheat hysteresis threshold δT s2 , the opening degree of the second main electronic expansion valve 52 remains unchanged at the current opening degree.

[0058] 3.3 Closing Conditions In the above heating operation mode, when the water tank temperature T tank < the outdoor ambient temperature T ao , it is regarded as meeting the closing condition of the dual-evaporator heating operation, and the fin heat exchange conventional heating operation is carried out.

[0059] Of course, the above are only typical examples of the present invention. In addition, the present invention may have many other specific implementation manners. Any technical solutions formed by equivalent replacement or equivalent transformation fall within the scope of protection required by the present invention.

Claims

1. A solar-air energy composite heat pump system based on self-sufficient energy storage cascade application, characterized in that: It includes a heat pump main unit module, a solar energy module and a hydraulic module connected through pipelines. The heat pump main unit module includes a fin heat exchanger (5), a fluorine-water heat exchanger (51), an active ejector economizer (12) and a conversion assembly. The solar energy module is used to convert solar energy into heat energy and store it in a hot water storage tank (31). The operating states of the heat pump main unit module include a fin heat exchange state and a fin heat exchange + fluorine-water heat exchange state. When the heat pump main unit module is in the fin heat exchange state, the conversion assembly connects the hot water storage tank (31) and the active ejector economizer (12), and the hot water in the hot water storage tank (31) serves as the external heat source of the active ejector economizer (12). When the heat pump main unit module is in the fin heat exchange + fluorine-water heat exchange state, the fluorine-water heat exchanger (51) is connected in parallel with the fin heat exchanger (5). On the one hand, the refrigerant in the fin heat exchanger exchanges heat with the air to absorb air energy. On the other hand, the conversion assembly connects the hot water storage tank (31) and the fluorine-water heat exchanger (51), and conveys the hot water in the hot water storage tank (31) to the fluorine-water heat exchanger (51) to absorb the heat of the stored hot water.

2. The solar-air energy composite heat pump system based on the self-sufficient energy storage cascade application according to claim 1, characterized in that: The active ejector economizer (12) includes an active injection inlet pipe (33) and an active injection outlet pipe (34). The active injection inlet pipe (33) and the active injection outlet pipe (34) are respectively connected to the water outlet and the water return port of the hot water storage tank (31) of the solar energy module. The conversion assembly includes an injection inlet three-way valve (54) and an injection outlet three-way valve (55). The injection inlet three-way valve (54) includes an a1 interface, a b1 interface and a c1 interface. The injection inlet three-way valve (54) is connected to the water outlet of the hot water storage tank (31) and the active injection inlet pipe (33) through the a1 interface and the b1 interface. The injection inlet three-way valve (54) is connected to the water outlet of the hot water storage tank (31) and the water inlet of the fluorine-water heat exchanger (51) through the a1 interface and the c1 interface. The injection outlet three-way valve (55) includes an a2 interface, a b2 interface and a c2 interface. The injection outlet three-way valve (55) is connected to the water inlet of the hot water storage tank (31) and the active injection outlet pipe (34) through the a2 interface and the b2 interface. The injection inlet three-way valve (54) is connected to the water inlet of the hot water storage tank (31) and the water outlet of the fluorine-water heat exchanger (51) through the a2 interface and the c2 interface.

3. The solar-air energy composite heat pump system based on self-sufficient energy storage cascade application according to claim 1, characterized in that: The heat pump main unit module includes a variable frequency compressor (1), an oil separator (3), a four-way valve (4), a fin heat exchanger (5), a subcooling electronic expansion valve (11). The exhaust pipe of the variable-frequency compressor (1) is connected to the d pipe of the four-way valve (4) through an oil separator (3). The c pipe of the four-way valve (4) is connected to one end of the fin heat exchanger (5). The e pipe of the four-way valve (4) is connected to the air pipe of the hydraulic module. The s pipe of the four-way valve (4) is connected to the inlet pipe of the gas-liquid separator (10). The outlet pipe of the gas-liquid separator (10) is connected to the suction pipe of the variable-frequency compressor (1). The other end of the fin heat exchanger (5) is connected to the main liquid pipe; The active jet enthalpy-increasing economizer (12) is connected with an active injection branch inlet pipe (13), an active injection branch outlet pipe (14), an active injection inlet water pipe (33) and an active injection outlet water pipe (34). Among them, the active injection branch inlet pipe (13) is communicated with the main liquid pipe, and the active injection branch outlet pipe (14) is connected to the intermediate pressure chamber connecting pipe of the variable-frequency compressor (1).

4. The solar-air energy composite heat pump system based on self-sufficient energy storage cascade application according to claim 1, characterized in that: The solar energy module includes a solar collector (21), the hot water storage tank (31), and a solar hot water pump (22). A heat storage hot water inlet pipe and a heat storage hot water return pipe are connected between the hot water storage tank (31) and the solar collector (21). The solar hot water pump (22) is installed on the heat storage hot water return pipe.

5. The solar-air energy composite heat pump system based on self-sufficient energy storage cascade application according to claim 2, wherein: The heat pump main unit module includes a liquid storage tank (7), a liquid pipe stop valve (8) and a gas pipe stop valve (9). The liquid pipe stop valve (8) and the gas pipe stop valve (9) are used to connect the hydraulic module. The gas pipe stop valve (9) is connected to the e pipe of the four-way valve (4). The liquid pipe stop valve (8) is connected to the liquid storage tank (7). The liquid storage tank (7) is connected to one end of the fin heat exchanger (5). The hydraulic module includes a condenser (41), a buffer tank (42) and a heating water pump (43). Among them, the gas pipe stop valve (9) is connected to the gas pipe of the condenser (41). The liquid pipe stop valve (8) is connected to the liquid pipe of the condenser (41). The heating water pump (43) is connected to the outlet water pipe of the condenser (41). The buffer tank (42) is connected to the inlet water pipe of the condenser (41).

6. The solar-air energy composite heat pump system based on the self-sufficient energy storage cascade application as claimed in claim 1, wherein: It further includes a temperature detection module. The temperature detection module includes an outdoor ambient temperature sensor, an exhaust temperature sensor, a suction temperature sensor, a coil temperature sensor on the fin heat exchanger, a liquid pipe temperature sensor, a water tank temperature sensor, an active jet enthalpy-increasing temperature detection component, a fin heat exchanger inlet temperature sensor, and a fluorine-water heat exchanger inlet temperature sensor; The outdoor ambient temperature sensor is used to detect the outdoor ambient temperature T ao , the exhaust gas temperature sensor is used to detect the exhaust gas temperature T d , the suction temperature sensor is used to detect the suction temperature T s , the coil temperature sensor is used to detect the coil temperature T def , the liquid pipe temperature sensor is used to detect the liquid pipe temperature T liq0 , the water tank temperature sensor is used to detect the temperature T of the hot water storage tank tank , the fin heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fin heat exchanger (5) liq1 , the outdoor water - fluorine heat exchanger inlet temperature sensor is used to detect the inlet temperature T of the fluorine - water heat exchanger (51) liq2 .

7. Control method of a solar-air energy composite heat pump system based on self-sufficient energy storage cascade application, providing the solar-air energy composite heat pump system based on self-sufficient energy storage cascade application as described in any one of claims 1-6, characterized in that: The control method includes Step S1: Configure the preset opening conditions for the conventional heating operation of the fin heat exchanger. When the opening conditions for the conventional heating operation of the fin heat exchanger are met, start the control of the conventional heating operation of the fin heat exchanger; Step S2A: Configure the preset opening conditions for the active jet enthalpy-increasing operation. When the opening conditions for the active jet enthalpy-increasing operation are met, start the active jet enthalpy-increasing heating control; Step S2B: Configure the preset closing conditions for the active jet enthalpy-increasing operation. When the closing conditions for the active jet enthalpy-increasing operation are met, stop the active jet enthalpy-increasing heating control; Step S3A: It is configured with a preset opening condition for the dual-evaporator heating operation. When the opening condition for the dual-evaporator heating operation is satisfied, the control for the dual-evaporator heating operation is turned on; Step S3B: It is configured with a preset closing condition for the dual-evaporator heating operation. When the closing condition for the dual-evaporator heating operation is satisfied, the control for the dual-evaporator heating operation is turned off.

8. The control method of the solar-air energy composite heat pump system based on the self-sufficient energy storage cascade application according to claim 7, characterized in that: In step S1, when the heat pump main unit module receives a heating start command and the return water temperature T w,in is less than the preset return water temperature threshold T w,in,set minus the preset return water temperature hysteresis threshold δT w,in , it is regarded as meeting the opening condition of the finned heat exchange conventional heating operation.

9. The control method of the solar-air energy composite heat pump system based on self-sufficient energy storage cascade application according to claim 7, characterized in that: In step S2A, when the unit starts the fin - type heat exchange for conventional heating operation, when the current exhaust superheat ΔT d > the preset first exhaust superheat ΔT d,set1 + the preset exhaust superheat hysteresis threshold δT d , and the current water tank temperature T tank > the current liquid line temperature T liq0 + the preset opening temperature hysteresis threshold δT liq0 , it is regarded as meeting the active jet - enhanced enthalpy heating operation start condition; In step S2B, when the unit is operating in active jet enthalpy increase heating mode, when it is detected that the actual exhaust superheat ΔT d ≤ the preset second exhaust superheat threshold ΔT d,set2 - the preset exhaust superheat hysteresis threshold δT d or when it is detected that the inlet temperature T of the heat source side of the active jet enthalpy increase h,inj,in < the refrigerant outlet temperature T of the active jet enthalpy increase r,inj,out + the preset first temperature hysteresis threshold δT h,r,set or the outlet temperature T of the heat source side of the active jet enthalpy increase h,inj,out <T r,inj,in + the preset second temperature hysteresis threshold δT h,r,set2 it is regarded as meeting the shutdown condition for the active jet enthalpy increase heating operation.

10. The control method of the solar-air energy composite heat pump system based on the self-sufficient energy storage cascade application as claimed in claim 7, wherein: In step S3A, when the unit is operating in the conventional fin heat exchange heating mode and does not meet the active jet enthalpy increase heating operation start condition, and the water tank temperature T tank > the outdoor ambient temperature T ao + the preset ambient temperature return difference threshold δT ao it is regarded as meeting the double evaporator heating operation start condition; In step S3B, when the unit is in the heating operation, the water tank temperature T tank <outdoor ambient temperature T ao , it is regarded as meeting the double-evaporator heating operation shutdown condition, and the fin heat exchange conventional heating operation is carried out.

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