A water heater integrating air source and water source and a control method

Abstract

This invention discloses a water heater that integrates air source and water source usage. Based on the existing product structure of water source heat pump water heaters that utilize waste heat in a cascade manner, an air source evaporator is added. This air source evaporator is connected in parallel with the evaporator of the first group of water source heat pumps and is connected to the condenser of the first group of water source heat pumps through a pipe valve. By switching the control valve, functions such as sequential direct heating of the two groups of water source heat pumps, complementary heating of air source heat pump and water source, independent heating of air source heat pump, and defrosting of air source evaporator are realized. This invention solves the problems existing in hot water supply such as initial hot water supply, insufficient waste heat, low hot water temperature, pipe circulation, and defrosting of air source heat pump at a lower cost.

Description

Technical Field

[0001] This invention belongs to the field of energy-saving hot water preparation technology, specifically relating to a hot water machine that integrates air source and water source and its control method. Background Technology

[0002] In public places, especially densely populated areas, bathrooms and hot water supply systems are essential basic facilities. Ensuring hot water supply in these places requires a significant amount of conventional energy daily. Statistics show that universities and public hospitals alone consume 1 billion tons of water annually for bathing, requiring 41 billion kWh of electricity for heating. Patent ZL2021207342255 discloses a wastewater waste heat three-stage cascade utilization water source heat pump hot water system, which has been commercialized as a product called "Waste Heat Cascade Utilization Water Source Heat Pump Hot Water Machine." This system recovers waste heat from bathing wastewater through three stages to heat tap water and the refrigerant in two sets of water source heat pump systems. The main structure consists of a water-to-water heat exchanger and a two-stage compression vapor refrigeration cycle device composed of two sets of water source evaporators and two sets of heat pump condensers. The water-to-water heat exchanger directly exchanges heat between wastewater and clean water, transferring the heat energy from the wastewater to the clean water—this is the first stage of heat recovery. Then, the remaining wastewater heat is used as the heat source for the water-source heat pump. Two evaporators sequentially absorb heat from the wastewater, raising its temperature. The heat is then released through refrigerant condensation to heat the clean water, thus reducing the energy consumption of the compressor in producing hot water and achieving energy conservation and carbon reduction. This three-stage wastewater and waste heat recovery technology can produce one ton of hot water for bathing from one ton of wastewater at 12℃ tap water, achieving a leading domestic and advanced international level in energy conservation and carbon reduction.

[0003] However, under abnormal operating conditions where no waste hot water is initially generated or the ambient temperature is too low (e.g., tap water temperature below 12℃), simply using waste heat from bathing to produce hot water is insufficient to produce one ton of hot water per ton of waste hot water. Even with the compressor's work, the set flow rate of hot water cannot be achieved. To compensate for this deficiency, a common practice is to add an auxiliary heating system to the hot water storage tank to preheat and store the water for later use. This auxiliary heating system may be an electric heating rod or an air source heat pump. However, the operating cost of electric heating rods is too high, and their high susceptibility to scaling reduces their thermal efficiency, making it difficult to guarantee long-term stable operation. Adding an air source heat pump, on the other hand, creates two separate operating devices from the existing waste heat cascade utilization water source heat pump water heater, requiring a larger footprint and increasing equipment costs. Furthermore, the actual usage time of the air source heat pump is relatively short, resulting in a waste of resources. Summary of the Invention

[0004] To address the aforementioned technical issues, this invention adds an air-source evaporator to the existing product structure of waste heat cascade utilization water source heat pump water heaters. This air-source evaporator is connected in parallel with the evaporator of the first group of water source heat pumps and is connected to the condenser of the first group of water source heat pumps via a pipe valve. By controlling the valve to switch between the two groups of water source heat pumps for sequential direct heating, complementary heating between the air source heat pump and the water source, independent heating by the air source heat pump, and defrosting of the air source evaporator, this invention solves problems in hot water supply such as initial hot water supply, insufficient waste heat, low hot water temperature, pipe circulation, and defrosting of the air source heat pump at a lower cost.

[0005] The technical solution provided by this invention is as follows: A water heater integrating air and water source usage includes a water-to-water heat exchanger, a water source heat pump I, and a water source heat pump II. The inlet of the waste hot water channel of the water-to-water heat exchanger is connected to a wastewater source, and the outlet of the waste hot water channel of the water-to-water heat exchanger is connected to the evaporator II in the water source heat pump II. The evaporator II is connected to the evaporator I of the water source heat pump I. The inlet of the clean water channel of the water-to-water heat exchanger is connected to tap water, and the outlet of the clean water channel is connected to the condenser I in the water source heat pump I. The condenser I is connected to the condenser II of the water source heat pump II. The condenser II, the evaporator II, and the gas-liquid separator II, compressor II, and electronic expansion valve II installed between them form a refrigerant circulation loop system II. The condenser I, the evaporator I, and the gas-liquid separator I and compressor I installed between them form a refrigerant circulation loop system II. The system includes an electronic expansion valve I forming a refrigerant circulation loop system I; it also includes an air source evaporator connected in parallel with the evaporator I in the refrigerant circulation loop system I. Additionally, a three-way valve I, a three-way valve II, and a four-way valve are installed on the refrigerant circulation loop system I. The refrigerant outlet of the condenser I is connected to the electronic expansion valve I. The three ports of the three-way valve I are connected to the electronic expansion valve I, the refrigerant inlet of the air source evaporator, and the refrigerant inlet of the evaporator I, respectively. The three ports of the three-way valve II are connected to the refrigerant outlet of the evaporator I, the gas-liquid separator I, and the four-way valve, respectively. The gas-liquid separator I, the compressor I, and the four-way valve are connected in sequence. The other two ports of the four-way valve are connected to the refrigerant outlet of the air source evaporator and the inlet of the condenser I, respectively.

[0006] Preferably, compressor I is a jet enthalpy-increasing compressor.

[0007] Preferably, it also includes a heat exchanger and an electronic expansion valve III. Three ports of the heat exchanger are respectively connected to the refrigerant outlets of the electronic expansion valve III, the compressor I, and the condenser I. The pipeline formed by the parallel connection of the electronic expansion valve I and the electronic expansion valve III is connected to the fourth port of the heat exchanger.

[0008] Preferably, the heat exchanger is a plate heat exchanger or a high-efficiency tank heat exchanger.

[0009] Preferably, it includes a first hot water preparation mode, a second hot water preparation mode, and a third hot water preparation mode; The first hot water preparation mode is direct heating. The air source evaporator is not activated. Only the heat source in the waste hot water is used. After the waste water flows out of the waste water tank, it enters the waste hot water channel of the water-to-water heat exchanger. After flowing out, it enters evaporator II and evaporator I in sequence to release heat and then is directly discharged into the public sewage network. Clean water enters the clean water channel of the water-to-water heat exchanger from the tap water supply pipe. After flowing out, it enters condenser I and condenser II in sequence to absorb heat and then directly enters the hot water tank. The second hot water preparation mode is a direct heating type. The air source evaporator is activated, but evaporator I is not. It utilizes both air energy and the heat energy from wastewater. Wastewater flows from the wastewater tank into the wastewater channel of the water-to-water heat exchanger, then flows into evaporator II to release heat before being directly discharged into the public sewage network. Clean water enters the clean water channel of the water-to-water heat exchanger from the tap water supply pipe, then flows into condenser I and condenser II to absorb heat before directly entering the hot water tank. In this hot water preparation mode, the refrigerant absorbs heat in the air source evaporator and then releases heat in condenser I, transferring the heat to the clean water. The third hot water preparation mode is a circulating heating type, which uses only air energy. When the air source evaporator is started, clean water flows out of the hot water tank and enters condenser I. After absorbing heat, it enters the hot water tank again and then enters condenser I to absorb heat again. This cycle of heat absorption continues until the set temperature is reached. In this hot water preparation mode, after the refrigerant absorbs heat in the air source evaporator, it enters condenser I to release heat and transfers the heat to the clean water.

[0010] Compared with the prior art, the present invention has the following technical advantages: (1) Compared with existing waste heat cascade utilization water source heat pump water heaters, this invention only requires the installation of one air source evaporator outdoors. The design is compact and reasonable, the overall indoor equipment footprint remains unchanged, and there is no need to add a refrigerant circulation loop system. The air source evaporator is directly connected in parallel with the evaporator of the first group of water source heat pumps, and connected to the condenser of the first group of water source heat pumps through a pipe valve. By controlling the valve to switch, the functions of sequential direct heating of the two groups of water source heat pumps, complementary heating of air source heat pump and water source, independent heating of air source heat pump, and defrosting of air source evaporator are realized. This solves the problems in hot water supply such as initial hot water supply, insufficient waste heat, low hot water temperature, pipe circulation, and defrosting of air source heat pump at a lower cost. Compared with directly using air source heat pump for auxiliary heating, the cost of configuring the equipment is reduced by 50%.

[0011] (2) In the first heat pump system, this invention replaces the ordinary compressor with a jet enthalpy-increasing compressor and adds a plate heat exchanger or a high-efficiency tank heat exchanger. The heat exchanger subcools the refrigerant in the main circulation loop before throttling, increasing the enthalpy difference. Simultaneously, it appropriately preheats the low-pressure, low-temperature refrigerant in the auxiliary loop (where the refrigerant is introduced directly from the middle of the compressor to participate in compression) after pressure reduction by the electronic expansion valve, achieving a suitable intermediate pressure for secondary compression by the compressor. This improves the performance of the air source heat pump under cold climate conditions and enhances its heating capacity in low-temperature environments. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a waste heat cascade utilization water source heat pump water heater in the background technology. Figure 2 This is a schematic diagram of the structure in the present invention. Figure 3 This is a flowchart illustrating the operation of the first hot water preparation mode in this invention. Figure 4 This is a flowchart illustrating the operation of the second hot water preparation mode in this invention. Figure 5 This is a flowchart illustrating the operation of the third hot water preparation mode in this invention. Figure 6 This is a flowchart illustrating the operation of the second defrosting mode in this invention. Figure 7 This is a flowchart illustrating the operation of the second defrosting mode in this invention. The components are as follows: 1. Water-to-water heat exchanger; 2. Condenser I; 3. Condenser II; 4. Hot water tank; 5. Evaporator II; 6. Evaporator I; 7. Air source evaporator; 8. Wastewater tank; 9. Wastewater pump I; 10. Wastewater pump II; 11. Three-way valve V; 12. Inlet valve; 13. Three-way valve III; 14. Three-way valve IV; 15. Electronic expansion valve II; 16. Gas-liquid separator II; 17. Compressor II; 18. Heat exchanger; 19. Electronic expansion valve I; 20. Three-way valve I; 21. Three-way valve II; 22. Gas-liquid separator I; 23. Compressor I; 24. Four-way valve; 25. Electronic expansion valve III. Detailed Implementation

[0013] The present invention will now be further described in conjunction with specific embodiments and accompanying drawings.

[0014] Figure 1This is a schematic diagram of the waste heat cascade utilization water source heat pump water heater of the background technology of this invention. From bottom to top, it consists of a water-to-water heat exchanger 1, a water source heat pump I, and a water source heat pump II. The heating path for clean water is as follows: after entering the heat exchanger, the clean water absorbs heat in one stage, and then sequentially enters the condenser I 2 in the water source heat pump I and the condenser II 3 in the water source heat pump II for two and three stages of heat absorption, and finally enters the hot water tank 4. The heat release path for waste hot water is as follows: the waste hot water releases heat in the water-to-water heat exchanger 1 in one stage, and then sequentially enters the evaporator II 5 in the water source heat pump II and the evaporator I 6 in the water source heat pump I for two and three stages of heat release, before being discharged to the public sewage network or a greywater treatment point. However, in summer when the tap water temperature is high and the demand for hot water for bathing is not high, the bathing wastewater, after two stages of heat absorption, is discharged directly to the public sewage network or a greywater treatment point without passing through the evaporator I 6 in the water source heat pump I.

[0015] and Figure 1 The difference lies in that the components related to the flow of waste hot water and clean water, as well as the connection methods between these components, remain unchanged in this invention. Regarding the refrigerant circuit system, the water source heat pump II remains unchanged. Two three-way valves and one four-way valve are added to the refrigerant circuit system of the water source heat pump I to complete the parallel connection of the air source evaporator 7 and evaporator I 6 in the refrigerant circuit system, as follows... Figure 2 As shown, this invention discloses a water heater integrating air source and water source utilization, mainly including a water-to-water heat exchanger 1, a water source heat pump I, and a water source heat pump II. A wastewater pump I 9 is installed at the inlet of a wastewater tank 8, and a wastewater pump II 10 is installed on the pipeline between the wastewater tank 8 and the water-to-water heat exchanger 1. The wastewater tank 8 is connected to the inlet of the waste hot water channel of the water-to-water heat exchanger 1. The outlet of the waste hot water channel of the water-to-water heat exchanger 1 is connected to the inlet interface of the evaporator II 5 in the water source heat pump II. The outlet interface of the evaporator II 5 is connected to the A interface of a three-way valve V 11. The B interface of the three-way valve V 11 is connected to the inlet interface of the evaporator I 6 of the water source heat pump I. The C interface of the three-way valve V 11 and the evaporator I... The outlet of water channel 6 is directly connected to the public sewage network or the greywater treatment point; the inlet of the clear water channel of water-to-water heat exchanger 1 is connected to the tap water supply pipe, and the tap water supply pipe is equipped with an inlet valve 12. The outlet of the clear water channel is connected to the B port of three-way valve III 13. The C port of three-way valve III 13 is connected to the hot water tank 4. The A port of three-way valve III 13 is connected to the inlet of condenser I 2 in water source heat pump I. The outlet of condenser I 2 is connected to the B port of three-way valve IV 14. The A port of three-way valve IV 14 is connected to the inlet of condenser II 3 in water source heat pump II. The outlet of condenser II 3 and the C port of three-way valve IV 14 are connected to the hot water tank 4. The pipeline formed by the above connection method is used for the flow heat absorption or heat exchange of wastewater and clear water in this invention.

[0016] The connection method of the refrigerant loop system in this invention will now be described. In the water source heat pump II, the refrigerant channel outlet of condenser II 3, electronic expansion valve II 15, refrigerant channel of evaporator II 5, gas-liquid separator II 16, compressor II 17, and refrigerant channel inlet of condenser II 3 are connected in sequence to form a refrigerant circulation loop system.

[0017] In the water source heat pump I, the refrigerant circuit system that uses waste heat from waste hot water to heat clean water is connected as follows: the refrigerant outlet of condenser I 2, heat exchanger 18, electronic expansion valve I 19, three-way valve I 20, refrigerant passage of evaporator I 6, three-way valve II 21, gas-liquid separator I 22, compressor I 23, four-way valve 24, and refrigerant inlet of condenser I 2 are connected in sequence to form a circuit.

[0018] In an air source heat pump, the refrigerant circuit system for heating clean water using an air source is connected as follows: the refrigerant outlet of condenser I2, heat exchanger 18, electronic expansion valve I 19, three-way valve I 20, refrigerant passage of air source evaporator 7, four-way valve 24 (in from port C, out from port D), three-way valve II 21, gas-liquid separator I 22, compressor I 23, four-way valve 24 (in from port A, out from port B), and the refrigerant inlet of condenser I2 are connected in sequence to form a circuit.

[0019] The first hot water preparation mode, the second hot water preparation mode, the third hot water preparation mode, the first defrosting mode, and the second defrosting mode of the present invention will now be described.

[0020] The first hot water preparation mode is activated when the waste heat from the bathing wastewater is sufficient to produce hot water at the set temperature and volume. In this mode, no air source is used; hot water is produced directly using only the waste heat from the bathing wastewater. Figure 3 As shown, the functional modes are water source heat pump I and water source heat pump II heating modes. Waste hot water route and direction: Waste hot water enters the water-to-water heat exchanger 1 for primary heat release, then sequentially enters the evaporator II 5 in water source heat pump II and the evaporator I 6 in water source heat pump I for secondary and tertiary heat release, before being discharged into the public sewage network or a greywater treatment point. Clean water route and direction: Clean water enters the water-to-water heat exchanger 1 for primary heat absorption, then sequentially enters the condenser I 2 in water source heat pump I and the condenser II 3 in water source heat pump II for secondary and tertiary heat absorption, finally entering the hot water tank 4.

[0021] The refrigerant flow path and direction of the water source heat pump I: The refrigerant flows out from the outlet B of the compressor I 23, and then sequentially through the four-way valve 24 (inlet A, outlet B), the refrigerant passage of the condenser I 2, the inlet A of the heat exchanger 18, the outlet B of the heat exchanger 18, the electronic expansion valve I 19, the three-way valve I 20 (inlet A, outlet B), the refrigerant passage of the evaporator I 6, the three-way valve II 21 (inlet B, outlet A), and the gas-liquid separator I 22, before entering the inlet A of the compressor I 23 to form a loop.

[0022] The compressor I 23 used in this invention is a vapor injection enthalpy-increasing compressor, which requires an additional electronic expansion valve III 25. The electronic expansion valve III 25 is located between the heat exchanger 18 and the electronic expansion valve I 19, and is connected to the inlet of the electronic expansion valve I 19 and the heat exchanger inlet C of the heat exchanger 18, respectively. The outlet D of the heat exchanger 18 is connected to the air inlet C of the compressor I 23.

[0023] The refrigerant flow path and direction of the water source heat pump II: out of the outlet B of compressor II 17, through the refrigerant passage of condenser II 3, electronic expansion valve II 15, refrigerant passage of evaporator II 5, gas-liquid separator II 16, and into the inlet A of compressor II 17 to form a loop.

[0024] In this mode, the control valves for the clean water pipeline are as follows: inlet valve 12 is open, three-way valve III 13 interface AB is open, and the rest are closed; three-way valve IV 14 interface AB is open, and the rest are closed. The control valves for the waste hot water pipeline are as follows: waste water pump II 10 is started, three-way valve V 11 interface AB is open, and the rest are closed. The control valves for the refrigerant circuit of the water source heat pump I are as follows: three-way valve I 20 interface AB is open, and the rest are closed; three-way valve II 21 interface AB is open, and the rest are closed; four-way valve 24 interface AB is open, and the rest are closed.

[0025] The second hot water preparation mode is activated when the temperature of the collected wastewater is too low to meet the heat energy required to produce hot water at the set temperature and volume. Figure 4 As shown, the functional modes are air source heat pump and water source heat pump II heating modes. This mode can be activated when the waste heat from the waste water cannot produce a sufficient amount of hot water for bathing. Waste water route and direction: Waste water enters the water-to-water heat exchanger 1 for primary heat release, then sequentially enters the evaporator II 5 in the water source heat pump II for secondary heat release, and is then directly discharged to the public sewage network or a greywater treatment point. Clean water route and direction: Clean water enters the water-to-water heat exchanger 1 for primary heat absorption, then sequentially enters the condenser I 2 and condenser II 3 for secondary and tertiary heat absorption, and finally enters the hot water tank 4. In this mode, the refrigerant absorbs heat in the air source evaporator 7 and then flows into the condenser I 2 for heat release, thus heating the clean water.

[0026] The refrigerant flow path and direction of the water source heat pump II: out of the outlet B of compressor II 17, through the refrigerant passage of condenser II 3, electronic expansion valve II 15, refrigerant passage of evaporator II 5, gas-liquid separator II 16, and into the inlet A of compressor II 17 to form a loop.

[0027] The refrigerant flow path and direction of the air source heat pump: The refrigerant flows out from outlet B of compressor I 23, and then sequentially through four-way valve 24 (inlet A, outlet B), the refrigerant passage of condenser I 2, inlet A of heat exchanger 18, outlet B of heat exchanger 18, electronic expansion valve I 19, three-way valve I 20 (inlet A, outlet C), the refrigerant passage of air source evaporator 7, four-way valve 24 (inlet C, outlet D), three-way valve II 21 (inlet C, outlet A), and gas-liquid separator I 22, before entering inlet A of compressor I 23 to form a loop.

[0028] The compressor I 23 used in this invention is a vapor injection enthalpy-increasing compressor, which requires an additional electronic expansion valve III 25. The electronic expansion valve III 25 is located between the heat exchanger 18 and the electronic expansion valve I 19, and is connected to the inlet of the electronic expansion valve I 19 and the heat exchanger inlet C of the heat exchanger 18, respectively. The outlet D of the heat exchanger 18 is connected to the air inlet C of the compressor I 23.

[0029] In this mode, the control valves for the clean water pipeline are as follows: inlet valve 12 is open, three-way valve III 13 interface AB is open, and the rest are closed; three-way valve IV 14 interface AB is open, and the rest are closed; the control valves for the waste hot water pipeline are as follows: waste water pump II 10 is started, three-way valve V 11 interface AC is open, and the rest are closed; the control valves for the refrigerant circuit of the water source heat pump I are as follows: three-way valve I 20 interface AC is open, and the rest are closed; three-way valve II 21 interface AC is open, and the rest are closed; four-way valve 24 interface AB is open, interface CD is open, and the rest are closed.

[0030] The third hot water preparation mode, such as Figure 5 As shown, the functional mode is the air source heat pump circulation heating mode, which does not use waste heat from waste hot water to heat clean water. This mode is mainly used when there is no waste hot water generated during initial use, and the clean water in hot water tank 4 needs to be heated to the set temperature using an air source heat pump to provide hot water for initial use. Alternatively, when the system is running and the water temperature in hot water tank 4 is lower than the set temperature, the clean water is circulated and heated to the set temperature by the air source heat pump. Clean water route and direction: The clean water in hot water tank 4 directly enters condenser I 2 to absorb heat, then directly enters hot water tank 1, and then enters condenser I 2 to absorb heat, circulating and absorbing heat until the set temperature is reached.

[0031] The refrigerant flow path and direction of the air source heat pump: The refrigerant flows out from outlet B of compressor I 23, and then sequentially through four-way valve 24 (inlet A, outlet B), the refrigerant passage of condenser I 2, inlet A of heat exchanger 18, outlet B of heat exchanger 18, electronic expansion valve I 19, three-way valve I 20 (inlet A, outlet C), the refrigerant passage of air source evaporator 7, four-way valve 24 (inlet C, outlet D), three-way valve II 21 (inlet C, outlet A), and gas-liquid separator I 22, before entering inlet A of compressor I 23 to form a loop.

[0032] The compressor I 23 used in this invention is a vapor injection enthalpy-increasing compressor, which requires an additional electronic expansion valve III 25. The electronic expansion valve III 25 is located between the heat exchanger 18 and the electronic expansion valve I 19, and is connected to the inlet of the electronic expansion valve I 19 and the heat exchanger inlet C of the heat exchanger 18, respectively. The outlet D of the heat exchanger 18 is connected to the air inlet C of the compressor I 23.

[0033] In this mode, the control valves for the clean water pipeline are as follows: inlet valve 12 is closed, three-way valve III 13 port AC is open, and the rest are closed; three-way valve IV 14 port CB is open, and the rest are closed; the control valves for the waste hot water pipeline are as follows: waste water pump II 10 is closed, and three-way valve V 11 is closed; the control valves for the refrigerant circuit of the air source heat pump are as follows: three-way valve I 20 port AC is open, and the rest are closed; three-way valve II 21 port AC is open, and the rest are closed; four-way valve 24 port AB is open, port CD is open, and the rest are closed.

[0034] In the first defrosting mode, the air source evaporator 7 is activated, but evaporator I 6 is not. The function is to defrost the air source evaporator 7 and heat the water source heat pump II. Wastewater route and direction: Waste hot water enters the water-to-water heat exchanger 1 for primary heat release, then enters the evaporator II 5 in the water source heat pump II for secondary heat release, before being directly discharged to the public sewage network or a greywater treatment point. Clean water route and direction (circulation): Clean water enters and sequentially enters the condenser I 2 for heat release, then absorbs heat in the condenser II 3, and then enters the hot water tank 4, repeating this process until the air source evaporator 7 defrosts. In this mode, the air source evaporator 7 operates in reverse, functioning as a condenser. Correspondingly, the refrigerant in the condenser I 2 flows in reverse, functioning as an evaporator. That is, the refrigerant absorbs heat in the condenser I 2 and releases heat in the air source evaporator 7, gradually defrosting the air source evaporator 7.

[0035] The refrigerant flow path and direction of the air source heat pump: The refrigerant flows out from the outlet B of compressor I 7, and then sequentially through four-way valve 24 (inlet A, outlet C), the refrigerant passage of air source evaporator 7, three-way valve I 20 (outlet A, outlet C), electronic expansion valve I 19, outlet B of heat exchanger 18, inlet A of heat exchanger 18, the refrigerant passage of condenser I 2, four-way valve 24 (inlet B, outlet D), three-way valve II 21 (inlet C, outlet A), gas-liquid separator I 22, and finally enters the inlet A of compressor I 23 to form a loop.

[0036] The compressor I 23 used in this invention is a vapor injection enthalpy-increasing compressor, which requires an additional electronic expansion valve III 25. The electronic expansion valve III 25 is located between the heat exchanger 18 and the electronic expansion valve I 19, and is connected to the inlet of the electronic expansion valve I 19 and the heat exchanger inlet C of the heat exchanger 18, respectively. The outlet D of the heat exchanger 18 is connected to the air inlet C of the compressor I 23.

[0037] In this mode, the control valves for the clean water pipeline are as follows: inlet valve 12 is closed, three-way valve III 13 port AC is open, and the rest are closed; three-way valve IV 14 port AB is open, and the rest are closed. The control valves for the waste hot water pipeline are as follows: waste water pump II 10 is started, three-way valve V 11 port AC is open, and the rest are closed. The control valves for the refrigerant circuit of the air source heat pump are as follows: three-way valve I 20 port AC is open, and the rest are closed; three-way valve II 21 port AC is open, and the rest are closed; four-way valve 24 port AC is open, port BD is open, and the rest are closed.

[0038] The second defrosting mode uses the air source evaporator 7, but does not activate evaporators II 5 or I 6. It does not use waste heat from the wastewater to heat the clean water, and functions as an air source circulating defrosting mode. Clean water circulates from the hot water tank 4, sequentially entering condenser I 2 to release heat before returning to the hot water tank 4, until the air source evaporator 7 defrosts. In this mode, the air source evaporator 7 operates in reverse, functioning as a condenser. Correspondingly, the refrigerant in condenser I 2 flows in reverse, functioning as an evaporator. That is, the refrigerant absorbs heat in condenser I 2 and releases heat in the air source evaporator 7, gradually defrosting the air source evaporator 7.

[0039] The refrigerant flow path and direction of the air source heat pump: The refrigerant flows out from the outlet B of compressor I 7, and then sequentially through four-way valve 24 (inlet A, outlet C), the refrigerant passage of air source evaporator 7, three-way valve I 20 (outlet A, outlet C), electronic expansion valve I 19, outlet B of heat exchanger 18, inlet A of heat exchanger 18, the refrigerant passage of condenser I 2, four-way valve 24 (inlet B, outlet D), three-way valve II 21 (inlet C, outlet A), gas-liquid separator I 22, and finally enters the inlet A of compressor I 23 to form a loop.

[0040] The compressor I 23 used in this invention is a vapor injection enthalpy-increasing compressor, which requires an additional electronic expansion valve III 25. The electronic expansion valve III 25 is located between the heat exchanger 18 and the electronic expansion valve I 19, and is connected to the inlet of the electronic expansion valve I 19 and the heat exchanger inlet C of the heat exchanger 18, respectively. The outlet D of the heat exchanger 18 is connected to the air inlet C of the compressor I 23.

[0041] In this mode, the control valves for the clean water pipeline are as follows: inlet valve 12 is closed, three-way valve III 13 port AC is open, and the rest are closed; three-way valve IV 14 port CB is open, and the rest are closed; the control valves for the waste hot water pipeline are as follows: waste water pump II 10 is closed, and three-way valve V 11 is closed; the control valves for the refrigerant circuit of the air source heat pump are as follows: three-way valve I 20 port AC is open, and the rest are closed; three-way valve II 21 port AC is open, and the rest are closed; four-way valve 24 port AC is open, port BD is open, and the rest are closed.

Claims

1. A water heater integrating air source and water source usage, comprising a water-to-water heat exchanger, a water source heat pump I, and a water source heat pump II; the inlet end of the waste hot water channel of the water-to-water heat exchanger is connected to a wastewater source, and the outlet of the waste hot water channel of the water-to-water heat exchanger is connected to the evaporator II in the water source heat pump II; the evaporator II is connected to the evaporator I of the water source heat pump I; the inlet of the clear water channel of the water-to-water heat exchanger is connected to tap water, and the outlet of the clear water channel is connected to the condenser I in the water source heat pump I; the condenser I is connected to the condenser II of the water source heat pump II; the condenser II, the evaporator II, and the gas-liquid separator II, compressor II, and electronic expansion valve II disposed between them form a refrigerant circulation loop system II; the condenser I, the evaporator I, and the gas-liquid separator I, compressor I, and electronic expansion valve I disposed between them form a refrigerant circulation loop system I; characterized in that: It also includes an air-source evaporator, which is connected in parallel with evaporator I in refrigerant circulation loop system I. Three-way valve I, three-way valve II, and four-way valve are also installed in refrigerant circulation loop system I. The refrigerant outlet of condenser I is connected to electronic expansion valve I. The three ports of three-way valve I are connected to electronic expansion valve I, the refrigerant inlet of the air-source evaporator, and the refrigerant inlet of evaporator I, respectively. The three ports of three-way valve II are connected to the refrigerant outlet of evaporator I, gas-liquid separator I, and four-way valve, respectively. Gas-liquid separator I, compressor I, and four-way valve are connected in sequence. The other two ports of the four-way valve are connected to the refrigerant outlet of the air-source evaporator and the inlet of condenser I, respectively.

2. A water heater integrating air source and water source functions as described in claim 1, characterized in that: Compressor I is a jet enthalpy-increasing compressor.

3. A water heater integrating air source and water source functions as described in claim 2, characterized in that: It also includes a heat exchanger and an electronic expansion valve III. Three of the heat exchanger's ports are connected to the refrigerant outlets of the electronic expansion valve III, compressor I, and condenser I, respectively. The pipeline formed by the parallel connection of electronic expansion valve I and electronic expansion valve III is connected to the fourth port of the heat exchanger.

4. A water heater integrating air source and water source functions as described in claim 3, characterized in that: Heat exchangers: plate heat exchangers or high-efficiency tank heat exchangers.

5. The control method for a water heater integrating air source and water source usage according to claim 2, characterized in that: This includes the first hot water preparation mode, the second hot water preparation mode, and the third hot water preparation mode; The first hot water preparation mode is direct heating. The air source evaporator is not activated. Only the heat source in the waste hot water is used. After the waste water flows out of the waste water tank, it enters the waste hot water channel of the water-to-water heat exchanger. After flowing out, it enters evaporator II and evaporator I in sequence to release heat and then is directly discharged into the public sewage network. Clean water enters the clean water channel of the water-to-water heat exchanger from the tap water supply pipe. After flowing out, it enters condenser I and condenser II in sequence to absorb heat and then directly enters the hot water tank. The second hot water preparation mode is a direct heating type. The air source evaporator is activated, but evaporator I is not. It utilizes both air energy and the heat energy from wastewater. Wastewater flows from the wastewater tank into the wastewater channel of the water-to-water heat exchanger, then flows into evaporator II to release heat before being directly discharged into the public sewage network. Clean water enters the clean water channel of the water-to-water heat exchanger from the tap water supply pipe, then flows into condenser I and condenser II to absorb heat before directly entering the hot water tank. In this hot water preparation mode, the refrigerant absorbs heat in the air source evaporator and then releases heat in condenser I, transferring the heat to the clean water. The third hot water preparation mode is a circulating heating type, which uses only air energy. When the air source evaporator is started, clean water flows out of the hot water tank and enters condenser I. After absorbing heat, it enters the hot water tank again and then enters condenser I to absorb heat again. This cycle of heat absorption continues until the set temperature is reached. In this hot water preparation mode, after the refrigerant absorbs heat in the air source evaporator, it enters condenser I to release heat and transfers the heat to the clean water.

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