A waste heat source, heat pump and gas furnace coupled hot water supply system

Abstract

The application discloses a heat supply system coupled with a waste heat source, a heat pump and a gas furnace, which comprises a gas furnace, a heat pump assembly, a heat release side of the heat pump assembly connected with the gas furnace and a user end respectively and forming a water flow circulation loop, and a waste heat source connected with a heat absorption side of the heat pump assembly to provide waste heat for the heat pump assembly. By connecting the waste heat source with the heat absorption side of the heat pump assembly, the heat pump assembly can fully utilize low-grade waste heat in an industrial process and convert the low-grade heat energy into high-grade heat energy, so that the waste heat source, the heat pump assembly and the gas furnace are coupled, and the energy efficiency of system operation is significantly improved.

Description

Technical Field

[0001] This application relates to the field of hot water supply system technology, and in particular to a hot water supply system coupled with a waste heat source, a heat pump and a gas furnace. Background Technology

[0002] In the supply of high-temperature hot water in industrial production, there is a common structural contradiction between the consumption of high-grade fuel and the idleness of low-grade waste heat. On the one hand, gas-fired boilers, as the main heat source, directly burn natural gas to meet process temperature requirements, but their high-grade chemical energy is wasted when used to prepare medium- and low-temperature hot water, resulting in energy efficiency losses due to "high quality, low utilization." On the other hand, a large amount of process waste heat (such as wastewater, cooling water, and flue gas) at 30℃-60℃ is discharged because it is too low in temperature to be directly utilized, resulting in energy waste.

[0003] In existing technologies, gas furnaces and waste heat recovery equipment (such as heat pumps) typically operate as two independent systems, lacking deep synergy in system configuration and control logic. This isolated operating mode prevents the system from dynamically and optimally integrating different grades of heat energy based on real-time operating conditions (such as waste heat temperature, energy prices, and load demand). It also makes it difficult to achieve the optimal match between maximizing the utilization of heat pump capacity and providing reasonable supplementation from the gas furnace, thus hindering further improvements in overall energy efficiency.

[0004] Therefore, how to break through the limitations of independent operation of existing equipment from the perspective of system configuration and control methods, and achieve deep coupling and intelligent collaboration between gas furnaces and heat pumps in terms of energy flow and information flow, has become a technical problem that urgently needs to be solved in this field.

[0005] Therefore, existing technologies still need to be improved and developed. Utility Model Content

[0006] The technical problem to be solved by this application is to provide a hot water supply system that couples a waste heat source, a heat pump and a gas furnace, in order to utilize low-grade waste heat and couple it with a gas furnace to improve the overall energy efficiency of the system.

[0007] The technical solution adopted by this application to solve the technical problem is as follows: A hot water supply system coupling a waste heat source, a heat pump, and a gas boiler, comprising: Gas stove; A heat pump assembly; the heat dissipation side of the heat pump assembly is connected to the gas furnace and the user end respectively, forming a water circulation loop; A waste heat source is connected to the heat absorption side of the heat pump assembly to provide waste heat to the heat pump assembly.

[0008] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, wherein the heat pump assembly includes: A high-temperature heat pump unit includes a two-stage compressor, a two-stage condenser, a two-stage expansion valve, and a two-stage evaporator connected in sequence to form a two-stage refrigerant circulation loop; the two-stage evaporator is connected to the waste heat source. A low-temperature stage heat pump unit; the heat release side of the low-temperature stage heat pump unit is connected to the inlet side of the secondary compressor and the outlet side of the secondary throttling valve respectively, so as to short-circuit the secondary evaporator; the heat absorption side of the low-temperature stage heat pump unit is connected to the waste heat source.

[0009] The hot water supply system, which is coupled with the waste heat source, heat pump, and gas furnace, wherein the operating temperature of the refrigerant corresponding to the low-temperature heat pump unit is lower than the operating temperature of the refrigerant corresponding to the high-temperature heat pump unit.

[0010] The hot water supply system coupled with the waste heat source, heat pump, and gas furnace, wherein the low-temperature stage heat pump unit includes: A single-stage compressor; The evaporator-condenser has a primary side inlet connected to the outlet side of the first-stage compressor, a secondary side inlet connected to the outlet side of the second-stage throttling valve, and a secondary side outlet connected to the inlet side of the second-stage compressor. A primary throttling valve is connected at its inlet side to the primary outlet of the evaporator-condenser. The primary side of the first-stage evaporator is connected to the outlet side of the first-stage throttling valve and the inlet side of the first-stage compressor, respectively; the secondary side of the first-stage evaporator is connected to the waste heat source.

[0011] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, further includes: The first valve group is installed on the secondary refrigerant circulation loop and is connected to the outlet side of the secondary throttling valve, the inlet side of the secondary evaporator, and the secondary inlet of the evaporator-condenser, respectively. The second valve group is installed on the secondary refrigerant circulation loop and is connected to the secondary side outlet of the evaporator-condenser, the outlet side of the secondary evaporator, and the inlet side of the secondary compressor, respectively.

[0012] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, wherein the secondary evaporator is connected in parallel with the primary evaporator and then connected to the outlet side of the waste heat source.

[0013] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, further includes: The third valve group is connected to the outlet side of the waste heat source, the secondary inlet of the first-stage evaporator, and the secondary inlet of the second-stage evaporator, respectively.

[0014] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, wherein the waste heat source, the primary evaporator, and the secondary evaporator are connected in series.

[0015] The hot water supply system, which couples the waste heat source, heat pump, and gas furnace, further includes: A flue gas heat exchanger is disposed between the user terminal and the heat pump assembly; the primary side of the flue gas heat exchanger is connected to the flue gas outlet of the gas furnace, and the secondary side of the flue gas heat exchanger is connected to the water outlet side of the user terminal and the heat release side of the heat pump assembly, respectively.

[0016] Beneficial Effects: This application connects the waste heat source to the heat-absorbing side of the heat pump component, enabling the heat pump component to fully utilize the low-grade waste heat from industrial processes to achieve refrigerant heat absorption and temperature rise. This couples the waste heat source, heat pump component, and gas furnace, significantly improving system operating energy efficiency. Simultaneously, the heat-releasing side of the heat pump component, the gas furnace, and the user end form a water circulation loop, allowing the heat pump component to directly supply hot water to the user. When the load is insufficient or higher-grade hot water is required, the gas furnace supplements the heating. Through this energy cascade utilization method, the system uses low-grade waste heat to drive the high-efficiency heat pump component to provide the main heating supply, while the gas furnace can handle peak demand or supplementary heating functions. This significantly reduces gas consumption, improves overall system energy efficiency, and ensures a continuous and stable output of high-temperature hot water to the user end. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a hot water supply system coupled with a waste heat source, a heat pump, and a gas furnace, where the secondary evaporator described in this application is connected in parallel with the primary evaporator and then connected to the outlet side of the waste heat source, and the first valve group, the second valve group, and the third valve group all include three-way valves. Figure 2 This is a schematic diagram of the structure of a hot water supply system coupled with a gas furnace when the waste heat source, the primary evaporator, and the secondary evaporator are connected in series. Figure 3 This is a schematic diagram of the hot water supply system coupled with the waste heat source, heat pump and gas furnace when the first valve group, the second valve group and the third valve group in this application each include two two-way valves; Figure 4 This is a schematic diagram of the hot water supply system coupled with the waste heat source, heat pump and gas furnace when the heat absorption unit in this application includes a three-way heat exchanger. Detailed Implementation

[0018] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or wireless coupling. The term “and / or” as used herein includes all or any units and all combinations of one or more associated listed items.

[0019] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the same meaning as in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless specifically defined as herein.

[0020] like Figure 1 and Figure 2 ( Figure 1 and Figure 2 As shown by the middle arrows (corresponding to the flow directions of water, refrigerant, and flue gas), this application provides a hot water supply system coupled with a waste heat source, a heat pump, and a gas furnace. The system includes a gas furnace 2, a heat pump assembly 1, and a waste heat source 3. The heat release side of the heat pump assembly 1 is connected to the gas furnace 2 and the user terminal 10, forming a water circulation loop. The waste heat source 3 is connected to the heat absorption side of the heat pump assembly 1 to provide waste heat to the heat pump assembly 1.

[0021] Specifically, the heat-dissipating side of the heat pump component 1 is connected to the water inlet side of the gas furnace 2 and the water outlet side of the user terminal 10, thereby forming a closed-loop water circulation circuit. This makes the heat-dissipating side of the heat pump component 1 and the gas furnace 2 connected in series. When both the heat pump component 1 and the gas furnace 2 are in operation, the water outlet of the user terminal 10 can be heated twice by passing through the heat pump component 1 and the gas furnace 2 in sequence before flowing back to the user terminal 10, thereby providing high-temperature hot water to the user terminal 10.

[0022] When heat pump component 1 is not in operation, it only supplies water flow and does not heat the water. Therefore, the water outlet at user terminal 10 is heated by gas boiler 2 and then flows back to user terminal 10, achieving independent heating by gas boiler 2.

[0023] The heat pump component 1 has its heat absorption side connected to the waste heat source 3, enabling it to utilize low-grade waste heat as a heat source. Through the heat absorption, compression, and release processes of the refrigerant circulating within the heat pump component 1, the low-temperature waste heat is utilized to provide high-temperature hot water, thus achieving the recovery of waste heat that was originally difficult to utilize directly. In this application, the heat pump component 1 utilizes the low-grade waste heat from the waste heat source 3, consuming less energy while producing hot water at the same temperature. The hot water produced by the heat pump component 1 forms a coupled heating structure with the gas furnace 2, allowing the heat pump component 1 to preferentially bear the basic heat load, while the gas furnace 2 only provides supplementary heating or peak load to the output of the heat pump component 1, thereby achieving efficient utilization of low-grade waste heat and reducing the heating load of the gas furnace 2.

[0024] Therefore, this application connects the waste heat source 3 to the heat absorption side of the heat pump component 1, enabling the heat pump component 1 to fully utilize the low-grade waste heat from the industrial process, converting low-grade heat energy into high-grade heat energy. This couples the waste heat source 3, the heat pump component 1, and the gas furnace 2, significantly improving the system's operating energy efficiency. Simultaneously, the heat release side of the heat pump component 1, the gas furnace 2, and the user terminal 10 form a water circulation loop, allowing the heat pump component 1 to directly supply hot water to the user. When the load is insufficient or higher-grade hot water is required, the gas furnace 2 supplements the heating. Through this energy cascade utilization method, the system uses low-grade waste heat to drive the high-efficiency heat pump component 1 to provide the main heating, while the gas furnace 2 can be used to handle peak or supplementary heating functions. This significantly reduces gas consumption, improves the overall system energy efficiency, and ensures a continuous and stable high-temperature hot water output from the user terminal 10.

[0025] This application is applicable to heating systems with large temperature differences between supply and return water, especially low return water temperature. Through multi-stage preheating and temperature enhancement design, the system can adapt to a wider range of industrial application scenarios and has a stronger buffering and adaptability to fluctuations in waste heat source 3, providing users with a stable, reliable and flexible high-quality heat source.

[0026] In one embodiment of this application, the heat pump assembly 1 includes a high-temperature stage heat pump unit 11, a low-temperature stage heat pump unit 12, and a heat absorption unit 13. The high-temperature stage heat pump unit 11 includes a secondary compressor 111, a secondary condenser 112, and a secondary throttling valve 113 connected in sequence to form a secondary refrigerant circulation loop. The heat absorption unit 13 has multiple refrigerant passages. The first refrigerant passage is connected to the inlet side of the secondary compressor 111 and the outlet side of the secondary throttling valve 113, respectively, and the second refrigerant passage is connected to the waste heat source 3. The low-temperature stage heat pump unit 12 includes a primary compressor 121, an evaporator-condenser 122, and a primary throttling valve 123. The third refrigerant passage of the heat absorption unit 13, the primary side of the primary compressor 121, the primary side of the evaporator-condenser 122, and the primary throttling valve 123 are connected in sequence to form a primary refrigerant circulation loop. The secondary side of the evaporator-condenser is connected to the secondary refrigerant circulation loop and is arranged in parallel with the first refrigerant passage to short-circuit the first refrigerant passage.

[0027] One embodiment of this application, such as Figure 1 As shown, the heat absorption unit 13 includes a primary evaporator 124 and a secondary evaporator 114. A third refrigerant passage is located on the primary side of the primary evaporator 124. The primary side of the primary evaporator 124 is connected to the outlet side of the primary throttle valve 123 and the inlet side of the primary compressor 121, forming a primary refrigerant circulation loop. A first refrigerant passage is located on the primary side of the secondary evaporator 114. The primary side of the secondary evaporator 114 is connected to the outlet side of the secondary throttle valve 113 and the inlet side of the secondary compressor 111, forming a secondary refrigerant circulation loop. The secondary sides of both the primary and secondary evaporators 124 are connected to the waste heat source 3 to form a second refrigerant passage.

[0028] Specifically, in the high-temperature heat pump unit 11, the secondary compressor 111 is sequentially connected to the primary side of the secondary condenser 112, the secondary throttling valve 113, and the primary side of the secondary evaporator 114, thus forming a two-stage refrigerant circulation loop. The secondary evaporator 114 serves as the heat absorption side of the high-temperature heat pump unit 11. When the high-temperature heat pump unit 11 is operating, it is connected to the waste heat source 3 via its secondary side, allowing the waste heat provided by the waste heat source 3 to exchange heat with the refrigerant flowing through the primary side of the secondary evaporator 114. The secondary side of the secondary condenser 112 is connected to the water outlet side of the user terminal 10 and the water inlet side of the gas boiler 2, thereby achieving the supply of high-temperature hot water through heat exchange with the high-temperature heat pump unit 11.

[0029] The heat-dissipating side (evaporator-condenser 122) of the low-temperature heat pump unit 12 is connected to the secondary refrigerant circulation loop, and the heat-absorbing side (primary evaporator 124) of the low-temperature heat pump unit 12 is connected to the waste heat source 3, so as to thermally couple the low-temperature heat pump unit 12 with the high-temperature heat pump unit 11, so that the heat output by the low-temperature heat pump unit 12 directly acts on the heat-absorbing side of the high-temperature heat pump unit 11, thereby raising the evaporation temperature of the refrigerant on the heat-absorbing side of the high-temperature heat pump unit 11, so that the two heat pump units operate simultaneously at mutually suitable thermal points, realizing cascaded synergistic heating.

[0030] Meanwhile, the heat absorption side of the low-temperature heat pump unit 12 is connected to the waste heat source 3, enabling the low-temperature heat pump unit 12 to obtain heat energy from low-grade waste heat. The low-temperature heat pump unit 12 is also connected to the secondary refrigerant circulation loop through the heat release side, thereby supplementing heat to the high-temperature heat pump unit 11, reducing the temperature difference between the condensing temperature and the evaporating temperature, and reducing the compression ratio. Even if the high-temperature heat pump unit 11 cannot efficiently absorb heat directly from the low-temperature waste heat provided by the waste heat source 3, the low-temperature heat pump unit 12 can still absorb heat through its connection with the waste heat source 3, thereby providing input to the high-temperature heat pump unit 11 and maximizing the utilization of low-grade waste heat. By making full use of low-grade waste heat, the overall energy efficiency of the system is improved, thereby enhancing the overall stability and reliability of the system.

[0031] Another embodiment of this application, such as Figure 4 As shown, the heat absorption unit 13 includes a three-way heat exchanger with three refrigerant passages. The first refrigerant passage is connected to the outlet side of the secondary throttle valve 113 and the inlet side of the secondary compressor 111, respectively. The second refrigerant passage is connected to the waste heat source 3, and the third refrigerant passage is connected to the outlet side of the primary throttle valve 123 and the inlet side of the primary compressor 121, respectively.

[0032] In this application, the operating temperature of the refrigerant in the low-temperature heat pump unit 12 is lower than the operating temperature of the refrigerant in the high-temperature heat pump unit 11.

[0033] Specifically, the goal of the high-temperature heat pump unit 11 is to produce high-grade hot water, so its refrigerant needs to have a high condensing temperature; while the function of the low-temperature heat pump unit 12 is to absorb low-grade waste heat and supply heat to the heat absorption side of the high-temperature heat pump unit 11, thereby increasing the heat in the middle, and reducing the condensing temperature required by the refrigerant in the low-temperature heat pump unit 12.

[0034] Therefore, the operating temperature of the refrigerant in the low-temperature stage heat pump unit 12 is lower than that of the refrigerant in the high-temperature stage heat pump unit 11. By using different refrigerants in the two-stage heat pump units, a temperature-graded improvement can be achieved, so that each stage of the heat pump unit operates within the optimal temperature range, effectively reducing the compression ratio and improving the overall energy efficiency and stability of the system.

[0035] In one embodiment of this application, the low-temperature stage heat pump unit 12 may use refrigerants such as R410A or R32 that are suitable for operation in the low-temperature range; the high-temperature stage heat pump unit 11 may use refrigerants such as R515B, R134a or R245fa that are suitable for operation in the medium-high temperature range.

[0036] The low-temperature heat pump unit 12 includes: a primary compressor 121, an evaporator-condenser 122, a primary throttling valve 123, and a primary evaporator 124; the primary side inlet of the evaporator-condenser 122 is connected to the outlet side of the primary compressor 121, the secondary side inlet of the evaporator-condenser 122 is connected to the outlet side of the secondary throttling valve 113, and the secondary side outlet is connected to the inlet side of the secondary compressor 111; the inlet side of the primary throttling valve 123 is connected to the primary side outlet of the evaporator-condenser 122; the primary side of the primary evaporator 124 is connected to both the outlet side of the primary throttling valve 123 and the inlet side of the primary compressor 121; and the secondary side of the primary evaporator 124 is connected to the waste heat source 3.

[0037] Specifically, the primary side of the evaporator-condenser 122 is connected to the first-stage compressor 121 and the first-stage throttle valve 123, thereby forming a refrigerant circulation loop in the low-temperature stage heat pump unit 12. The secondary side of the evaporator-condenser 122 is connected to the second-stage refrigerant circulation loop and is connected to the outlet side of the second-stage throttle valve 113 and the inlet side of the second-stage compressor 111, thereby short-circuiting the second-stage evaporator 114. The evaporator-condenser 122 is used for both the refrigerant circulation of the low-temperature stage heat pump unit 12 and the refrigerant circulation of the high-temperature stage heat pump unit 11, so that when the two-stage heat pump is working, energy exchange and heat transfer are achieved between the low-temperature stage circulation and the high-temperature stage circulation through the evaporator-condenser 122.

[0038] In one embodiment of this application, the hot water supply system coupled with the waste heat source, heat pump, and gas furnace further includes a first valve group 4 and a second valve group 5; wherein, the first valve group 4 is disposed on the secondary refrigerant circulation loop and is connected to the outlet side of the secondary throttling valve 113, the inlet side of the secondary evaporator 114, and the secondary side inlet of the evaporator-condenser 122 respectively; the second valve group 5 is disposed on the secondary refrigerant circulation loop and is connected to the secondary side outlet of the evaporator-condenser 122, the outlet side of the secondary evaporator 114, and the inlet side of the secondary compressor 111 respectively.

[0039] One implementation method in this embodiment, such as Figure 1 As shown, both the first valve group 4 and the second valve group 5 are three-way valves; the first valve group 4 is set on the secondary refrigerant circulation loop and has one inlet end and two outlet ends; wherein, the inlet end of the first valve group 4 is connected to the outlet end of the secondary throttling valve 113, the first outlet end of the first valve group 4 is connected to the secondary side inlet of the evaporator condenser 122, and the second outlet end of the first valve group 4 is connected to the primary side inlet of the secondary evaporator 114.

[0040] The second valve group 5 is also located on the secondary refrigerant circulation loop and has two inlet ends and one outlet end; wherein, the first inlet end of the second valve group 5 is connected to the primary side outlet of the secondary evaporator 114, the second inlet end of the second valve group 5 is connected to the secondary side outlet of the evaporator condenser 122, and the outlet end of the second valve group 5 is connected to the inlet of the secondary compressor 111.

[0041] When using the single-stage heat pump independent heating mode, the gas furnace 2 is shut down and only used for water supply. The single-stage heat pump heating is provided by the high-temperature heat pump unit 11, which consists of a two-stage compressor 111, a two-stage condenser 112, a two-stage throttling valve 113, and a two-stage evaporator 114. At this time, the inlet end of the first valve group 4 is open, the first outlet end of the first valve group 4 is closed, the second outlet end of the first valve group 4 is open, the first inlet end of the second valve group 5 is open, the second inlet end of the second valve group 5 is closed, and the outlet end of the second valve group 5 is open.

[0042] When a single-stage heat pump coupled with a gas furnace is used for heating, the gas furnace 2 is turned on, and the single-stage heat pump heating is provided by a high-temperature heat pump unit 11 consisting of a two-stage compressor 111, a two-stage condenser 112, a two-stage throttling valve 113, and a two-stage evaporator 114. At this time, the inlet end of the first valve group 4 is open, the first outlet end of the first valve group 4 is closed, the second outlet end of the first valve group 4 is open, the first inlet end of the second valve group 5 is open, the second inlet end of the second valve group 5 is closed, and the outlet end of the second valve group 5 is open.

[0043] When the two-stage heat pump independent heating mode is adopted, the gas furnace 2 is turned off and is only used for water supply. The low-temperature heat pump unit 12 and the high-temperature heat pump unit 11 are both turned on. At this time, the inlet end of the first valve group 4 is open, the first outlet end of the first valve group 4 is open, the second outlet end of the first valve group 4 is closed, the first inlet end of the second valve group 5 is closed, the second inlet end of the second valve group 5 is open, and the outlet end of the second valve group 5 is open.

[0044] When a two-stage heat pump coupled with a gas furnace is used for heating, the gas furnace 2 is turned on, and both the primary and secondary refrigerant circulation loops provide heating. At this time, the inlet end of the first valve group 4 is open, the first outlet end of the first valve group 4 is open, the second outlet end of the first valve group 4 is closed, the first inlet end of the second valve group 5 is closed, the second inlet end of the second valve group 5 is open, and the outlet end of the second valve group 5 is open.

[0045] When the gas furnace 2 is used in the independent heating mode, the gas furnace 2 is turned on, the heat pump component 1 is turned off and is only used for water supply.

[0046] Another implementation method in this embodiment, such as Figure 3As shown, the first valve group 4 includes two two-way valves 41 and 42. Two-way valve 41 is connected to the outlet side of the secondary throttling valve 113 and the inlet side of the secondary side of the evaporator-condenser 122, respectively. Two-way valve 42 is connected to the outlet side of the secondary throttling valve 113 and the inlet side of the primary side of the secondary evaporator 114, respectively. The second valve group 5 includes two two-way valves 51 and 52. Two-way valve 51 is connected to the outlet side of the primary side of the secondary evaporator 114 and the inlet side of the secondary compressor 111, respectively. Two-way valve 52 is connected to the outlet side of the secondary side of the evaporator-condenser 122 and the inlet side of the secondary compressor 111, respectively.

[0047] When electricity prices are low or gas prices are high, and waste heat source 3 is sufficient, the heat pump heating is more economical than the gas boiler 2. Heat pump component 1 can efficiently replace gas boiler 2 to bear the entire heating load, so heat pump component 1 is preferred for heating. Specifically, when the waste heat temperature is high, the single-stage cycle energy efficiency of heat pump component 1 is high, so the single-stage heat pump independent heating mode is preferred; when the waste heat temperature is low, the two-stage cycle energy efficiency of heat pump component 1 is high, so the two-stage heat pump independent heating mode is preferred.

[0048] When electricity prices are high or gas prices are low, the heating economy of heat pump component 1 decreases. In this case, the independent heating mode of gas boiler 2 is preferred, or the return water is first heated to an intermediate temperature in the high-efficiency operating range of heat pump component 1, and then the gas boiler 2 supplements the heat to the target supply water temperature (i.e., heat pump component 1 and gas boiler 2 are coupled for heating). Thus, through the synergistic mode of heat pump component 1 preheating and gas boiler 2 precisely supplementing the heat, a stable heating temperature and water volume are ensured, and the system's operating economy is guaranteed under all-weather conditions, achieving a balance between high energy efficiency and low-cost heating.

[0049] When waste heat resources are insufficient, the heating capacity of heat pump component 1 is limited regardless of whether the electricity price is high or low. At this time, the return water can be heated to the intermediate temperature in the high-efficiency operating range of heat pump component 1, and then the gas boiler 2 can supplement the heat to the target supply water temperature (that is, heat pump component 1 and gas boiler 2 are coupled for heating). Thus, through the synergistic mode of preheating of heat pump component 1 and precise supplementation of heat by gas boiler 2, a stable heating temperature and water volume are ensured, and the system is also ensured to operate economically under all-weather conditions, achieving a balance between high energy efficiency and low-cost heating.

[0050] As can be seen, this application breaks the traditional pattern of independent operation between gas-fired boiler systems and waste heat recovery systems. By appropriately adjusting and switching the execution strategy, it achieves complementary advantages between the two energy sources. The system can dynamically select the optimal operating mode based on real-time electricity prices and waste heat resource conditions, maximizing the value of low-grade waste heat and ensuring that the heat pump unit always operates within its high-efficiency range, thereby achieving a leapfrog improvement in the overall energy utilization efficiency of the entire heating system.

[0051] One embodiment of this application, such as Figure 1 As shown, the secondary side of the secondary evaporator 114 is connected in parallel with the secondary side of the primary evaporator 124 and then connected to the outlet side of the waste heat source 3. The hot water supply system coupled with the waste heat source, heat pump and gas furnace also includes a third valve group 6, which is connected to the outlet side of the waste heat source 3, the secondary side inlet of the primary evaporator 124 and the secondary side inlet of the secondary evaporator 114 respectively.

[0052] One implementation method in this embodiment, such as Figure 1 As shown, the third valve group 6 adopts a three-way valve, and the third valve group 6 has one inlet end and two outlet ends; wherein, the inlet end of the third valve group 6 is connected to the outlet of the waste heat source 3, the first outlet end of the third valve group 6 is connected to the secondary side inlet of the first-stage evaporator 124, and the second outlet end of the third valve group 6 is connected to the secondary side inlet of the second-stage evaporator 114.

[0053] When the system adopts a single-stage heat pump independent heating mode or a single-stage heat pump coupled with a gas furnace heating mode, the inlet end of the third valve group 6 is open, the first outlet end of the third valve group 6 is closed, and the second outlet end of the third valve group 6 is open. The waste heat source 3 only supplies waste heat to the secondary evaporator 114.

[0054] When the system adopts a two-stage heat pump independent heating mode or a two-stage heat pump coupled with a gas furnace heating mode, the inlet end of the third valve group 6 is opened, the first outlet end of the third valve group 6 is opened, and the second outlet end of the third valve group 6 is closed. The waste heat source 3 only supplies waste heat to the first-stage evaporator 124.

[0055] Another implementation method in this embodiment, such as Figure 3 As shown, the third valve group 6 includes two two-way valves 61 and 62. The two-way valve 61 is connected to the waste heat source 3 and the inlet side of the secondary side of the first-stage evaporator 124, respectively. The two-way valve 62 is connected to the waste heat source 3 and the inlet side of the secondary side of the second-stage evaporator 114, respectively. It is understandable that the first valve group 4, the second valve group 5, the third valve group 6, and the heat absorption unit 13 can be combined in any way. For example, the first valve group 4, the second valve group 5, and the third valve group 6 can all include three-way valves, while the heat absorption unit 13 includes a primary evaporator 124 and a secondary evaporator 114; or the first valve group 4, the second valve group 5, and the third valve group 6 can all include three-way valves, while the heat absorption unit 13 includes a three-way heat exchanger; or the first valve group 4 includes two two-way valves 41 and 42, the second valve group 5 and the third valve group 6 can all include three-way valves, while the heat absorption unit 13 includes a primary evaporator 124 and a secondary evaporator 114; or the first valve group 4 includes two two-way valves 41 and 42, the second valve group 5 and the third valve group 6 can all include three-way valves, while the heat absorption unit 13 includes a three-way heat exchanger, and so on.

[0056] Another embodiment of this application, such as Figure 2 As shown, the waste heat source 3, the secondary side of the primary evaporator 124, and the secondary side of the secondary evaporator 114 are connected in series.

[0057] Specifically, the outlet of waste heat source 3, the secondary side inlet of primary evaporator 124, the secondary side outlet of primary evaporator 124, the secondary side inlet of secondary evaporator 114, and the secondary side outlet of secondary evaporator 114 are connected sequentially. When the system adopts a single-stage heat pump independent heating mode, or a single-stage heat pump coupled with a gas furnace heating mode, the low-temperature stage heat pump unit 12 is turned off, the high-temperature stage heat pump unit 11 is turned on, and the secondary side of primary evaporator 124 does not utilize waste heat but only allows waste heat to pass through. When the system adopts a two-stage heat pump independent heating mode, or a two-stage heat pump coupled with a gas furnace heating mode, both low-temperature stage heat pump unit 12 and high-temperature stage heat pump unit 11 are turned on, and the secondary side of secondary evaporator 114 does not utilize waste heat.

[0058] In one embodiment of this application, the hot water supply system coupled with the waste heat source, heat pump and gas furnace further includes a flue gas heat exchanger 7, which is disposed between the user terminal 10 and the heat pump assembly 1. The primary side of the flue gas heat exchanger 7 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 7 is connected to the water outlet side of the user terminal 10 and the heat release side of the heat pump assembly 1, respectively.

[0059] Specifically, the primary side of the flue gas heat exchanger 7 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 7 is connected to the water outlet of the user terminal 10 and the secondary side of the secondary condenser 112. The water outlet of the user terminal 10 first exchanges heat with the high-temperature flue gas generated by the gas furnace 2 through the secondary side of the flue gas heat exchanger 7, and then enters the secondary side of the secondary condenser 112, thereby preheating the return water from the user terminal 10 to the heat pump assembly 1 and / or the gas furnace 2, further reducing the gas consumption and flue gas losses of the gas furnace 2. This dual energy-saving mechanism enables the system to significantly reduce fuel consumption and carbon dioxide emissions while providing the same amount of heat, resulting in outstanding environmental benefits.

[0060] It should be understood that the application of this application is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A hot water supply system coupling a waste heat source, a heat pump, and a gas furnace, characterized in that, It includes: Gas stove; Heat pump components; The heat pump assembly's heat-dissipating side is connected to the gas furnace and the user end, respectively, forming a water circulation loop; A waste heat source is connected to the heat absorption side of the heat pump assembly to provide waste heat to the heat pump assembly.

2. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 1, characterized in that, The heat pump assembly includes: The high-temperature heat pump unit includes a two-stage compressor, a two-stage condenser, and a two-stage throttling valve connected in sequence to form a two-stage refrigerant circulation loop; The heat absorption unit has multiple refrigerant passages; wherein, the first refrigerant passage is connected to the inlet side of the secondary compressor and the outlet side of the secondary throttling valve, and the second refrigerant passage is connected to the waste heat source; The low-temperature heat pump unit includes a primary compressor, an evaporator-condenser, and a primary throttling valve; the third refrigerant passage of the heat absorption unit, the primary compressor, the primary side of the evaporator-condenser, and the primary throttling valve are sequentially connected to form a primary refrigerant circulation loop; the secondary side of the evaporator-condenser is connected to the secondary refrigerant circulation loop and is arranged in parallel with the first refrigerant passage to short-circuit the first refrigerant passage.

3. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 2, characterized in that, The operating temperature of the refrigerant in the low-temperature heat pump unit is lower than that of the refrigerant in the high-temperature heat pump unit.

4. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 2, characterized in that, The heat absorption unit includes: The first-stage evaporator; the third refrigerant passage is located on the primary side of the first-stage evaporator; A secondary evaporator; the first refrigerant passage is located on the primary side of the secondary evaporator; The secondary side of the first-stage evaporator is connected in parallel or in series with the secondary side of the second-stage evaporator to form the second refrigerant passage.

5. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 2, characterized in that, The heat absorption unit includes: A three-way heat exchanger has a first refrigerant passage, a second refrigerant passage, and a third refrigerant passage.

6. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 4, characterized in that, It also includes: The first valve group is installed on the secondary refrigerant circulation loop and is connected to the outlet side of the secondary throttling valve, the inlet side of the secondary evaporator, and the secondary inlet of the evaporator-condenser, respectively. The second valve group is installed on the secondary refrigerant circulation loop and is connected to the secondary side outlet of the evaporator-condenser, the outlet side of the secondary evaporator, and the inlet side of the secondary compressor, respectively.

7. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 4, characterized in that, The secondary evaporator is connected in parallel with the primary evaporator and then connected to the outlet side of the waste heat source.

8. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 7, characterized in that, It also includes: The third valve group is connected to the outlet side of the waste heat source, the secondary inlet of the first-stage evaporator, and the secondary inlet of the second-stage evaporator, respectively.

9. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 4, characterized in that, The waste heat source, the primary evaporator, and the secondary evaporator are connected in series.

10. The hot water supply system coupled with a waste heat source, heat pump, and gas furnace according to claim 1, characterized in that, It also includes: A flue gas heat exchanger is disposed between the user terminal and the heat pump assembly; the primary side of the flue gas heat exchanger is connected to the flue gas outlet of the gas furnace, and the secondary side of the flue gas heat exchanger is connected to the water outlet side of the user terminal and the heat release side of the heat pump assembly, respectively.

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