A gas-electricity complementary hot water supply system

Abstract

The application discloses a gas-electricity complementary hot water supply system, which comprises a heat pump assembly, a gas stove connected with a water inlet side of a user end at a water outlet side, a first valve group connected with the water outlet side of the heat pump assembly at an inlet end and connected with the water inlet side of the user end at two outlet ends to form two parallel water flow circuits, the gas stove being communicated with one of the water flow circuits, a second valve group located between the user end and the heat pump assembly, and the second valve group being connected with a water outlet side of the user end at an inlet end and connected with the heat pump assembly and the gas stove at two outlet ends. The first valve group and the second valve group arranged between the heat pump assembly and the gas stove realize quick switching of water flow among "heat pump direct supply", "heat pump-gas stove series heating" and "gas stove direct supply", so that gas-electricity complementary, efficient and stable heating and lower operation cost are realized, and the energy efficiency utilization rate of the system is improved.

Description

Technical Field

[0001] This application relates to the field of heating system technology, and in particular to a gas-electric hybrid hot water supply system. Background Technology

[0002] Currently, the mainstream high-temperature hot water supply technologies mainly include hot water supply systems using a single air source heat pump and hot water supply systems using a single gas-fired boiler (such as...). Figure 1 (As shown) Two categories.

[0003] However, in existing residential or commercial hot water systems, the heating capacity of a single heat pump is significantly reduced in low-temperature environments, and the outlet water temperature is limited, making it difficult to continuously provide high-temperature hot water in cold seasons or when water usage is high. Furthermore, frequent start-ups and shutdowns can affect the system's lifespan. While a single gas boiler can heat up quickly, its energy efficiency is limited by combustion efficiency and flue gas losses, resulting in higher operating costs. Moreover, the sensible and latent heat in the flue gas cannot be effectively recovered, leading to low energy utilization.

[0004] Therefore, existing hot water supply methods that use a single heat source generally suffer from low energy efficiency, and existing technologies still need to be improved and developed. Utility Model Content

[0005] The technical problem to be solved by this application is to provide a gas-electric complementary hot water supply system to address the above-mentioned deficiencies of the prior art, which aims to solve the problem of low energy efficiency caused by the use of a single heat source to supply hot water in the prior art.

[0006] The technical solution adopted by this application to solve the technical problem is as follows: A gas-electric hybrid hot water supply system, comprising: Heat pump components; The gas boiler has its outlet side connected to the inlet side at the user's end. The first valve group has its inlet end connected to the outlet side of the heat pump assembly, and both outlet ends connected to the inlet side of the user end, forming two parallel water flow loops; the gas furnace is connected to one of the water flow loops. The second valve assembly is located between the user terminal and the heat pump assembly; the inlet end of the second valve assembly is connected to the water outlet side of the user terminal, one outlet end is connected to the heat pump assembly, and the other outlet end is connected in series with the gas furnace through the heat pump assembly.

[0007] The gas-electric hybrid hot water supply system, wherein the heat pump component includes: A primary heat pump unit includes a primary compressor, a primary evaporator, and a primary throttling valve connected in sequence. A two-stage heat pump unit includes a two-stage compressor, a two-stage condenser, and a two-stage throttling valve connected in sequence; the inlet end of the first valve group is connected to the outlet side of the two-stage condenser. The heat exchange unit is connected in part between the primary compressor and the primary throttling valve to form a first refrigerant circulation path; and in part between the secondary compressor and the secondary throttling valve to form a second refrigerant circulation path; the two outlet ends of the second valve group are respectively connected to the water inlet side of the secondary condenser and the heat exchange unit; the water outlet side of the heat exchange unit is also connected to the water inlet side of the gas furnace through a pipeline.

[0008] In the gas-electric complementary hot water supply system, the operating temperature of the refrigerant in the primary heat pump unit is lower than that of the refrigerant in the secondary heat pump unit.

[0009] The gas-electric hybrid hot water supply system, wherein the heat exchange unit includes: A first-stage condenser is connected to both the first-stage compressor and the first-stage expansion valve to form the first refrigerant circulation path; The secondary evaporator is connected to the secondary compressor and the secondary expansion valve respectively to form the second refrigerant circulation path; A water tank; the water inlet side of the water tank is connected to the second valve group and the secondary side outlet of the second-stage evaporator respectively; the water outlet side of the water tank is connected to the secondary side inlet of the first-stage condenser. The first connecting pipe is connected to the secondary side outlet of the first-stage condenser and the secondary side inlet of the second-stage evaporator, respectively, to form a first closed-loop water flow path between the first-stage condenser, the second-stage evaporator and the water tank.

[0010] The gas-electric hybrid hot water supply system further includes: A flue gas heat exchanger; 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 used to connect to the first closed-loop water flow path and the water inlet side of the gas furnace, respectively.

[0011] In the gas-electric complementary hot water supply system, one end of the pipeline is connected to the outlet side of the water tank, and the other end is connected to the inlet side of the gas furnace through the secondary side of the flue gas heat exchanger.

[0012] The gas-electric hybrid hot water supply system further includes: A flue gas heat exchanger; 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 used to connect to the first closed-loop water flow path.

[0013] The gas-electric hybrid hot water supply system further includes: The third valve group is installed on the first closed-loop water flow path and is located between the first-stage condenser and the second-stage evaporator; The second connecting pipe is connected at one end to the outlet side of the third valve group, and at the other end to the secondary side inlet of the secondary evaporator through the secondary side of the flue gas heat exchanger, so as to form a second closed-loop water flow path between the flue gas heat exchanger, the secondary side of the secondary evaporator, the water tank and the secondary side of the primary condenser.

[0014] The gas-electric hybrid hot water supply system, wherein the heat exchange unit includes: A three-way heat exchanger; the first flow path of the three-way heat exchanger is connected to the first-stage compressor and the first-stage throttling valve respectively to form the first refrigerant circulation flow path; the second flow path of the three-way heat exchanger is connected to the second-stage compressor and the second-stage throttling valve respectively to form the second refrigerant circulation flow path; the third flow path of the three-way heat exchanger is connected to the second valve group and the gas furnace respectively.

[0015] The gas-electric hybrid hot water supply system further includes: Flue gas heat exchanger; 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 three-way heat exchanger.

[0016] Beneficial effects: This application achieves rapid switching of water flow between "direct heat pump supply", "heat pump-gas furnace series heating", and "direct gas furnace supply" by setting a first valve group and a second valve group between the heat pump component and the gas furnace. This allows the heat source selection and water flow path to be automatically optimized according to ambient temperature, outlet water temperature requirements, and load changes. When the heat pump efficiency is high, it can directly supply heat to reduce energy consumption. When the ambient temperature is low or high-temperature outlet water is required, the water can be preheated by the heat pump before entering the gas furnace for enhanced heating, avoiding insufficient water supply caused by the low-temperature attenuation of the heat pump. At the same time, it reduces energy waste caused by cold water entering the gas furnace, thereby achieving gas-electric complementarity, high efficiency, continuous and stable heating, and lower operating costs, improving the energy efficiency of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a current technology where a single gas-fired boiler supplies hot water to the user. Figure 2 This is a schematic diagram of the gas-electric complementary hot water supply system in Embodiment 1 of this application; Figure 3 This is a schematic diagram of the gas-electric complementary hot water supply system when the dual-stage heat pump independent heating mode is implemented. Figure 4 This is a schematic diagram of the gas-electric complementary hot water supply system when the two-stage heat pump and gas furnace are coupled for heating. Figure 5 This is a schematic diagram of the gas-electric complementary hot water supply system when the primary heat pump and gas furnace are coupled for heating. Figure 6 A schematic diagram of the gas-electric complementary hot water supply system when the gas boiler is in independent heating mode; Figure 7 This is a schematic diagram of the gas-electric complementary hot water supply system in Embodiment 2 of this application; Figure 8 This is a schematic diagram of the connection structure of a four-way valve in a primary heat pump unit. Figure 9 This is a schematic diagram of the gas-electric complementary hot water supply system when both the first valve group and the second valve group in this application include two two-way valves. 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 2 ( Figure 2As shown by the arrows (corresponding to the flow directions of water, refrigerant, and flue gas), this application provides a gas-electric complementary hot water supply system, which includes: a heat pump assembly 1, a gas boiler 2, a first valve group 3, and a second valve group 4; the outlet side of the gas boiler 2 is connected to the inlet side of the user terminal 100; the inlet end of the first valve group 3 is connected to the outlet side of the heat pump assembly 1, and both outlet ends of the first valve group 3 are connected to the inlet side of the user terminal 100 to form two parallel water flow loops; the gas boiler 2 is connected to one of the water flow loops; the second valve group 4 is located between the user terminal 100 and the heat pump assembly 1; the inlet end of the second valve group 4 is connected to the outlet side of the user terminal 100, and the two outlet ends of the second valve group 4 are respectively connected to the heat pump assembly 1 and the gas boiler 2.

[0021] Specifically, the outlet side of the gas boiler 2 is connected to the inlet side of the user terminal 100; the inlet end of the first valve group 3 is connected to the outlet side of the heat pump assembly 1; the first outlet end of the first valve group 3 is directly connected to the inlet side of the user terminal 100; and the second outlet end of the first valve group 3 is connected to the inlet side of the user terminal 100 through the gas boiler 2 (that is, the second outlet end of the first valve group 3 is connected to the inlet side of the gas boiler 2, and is connected to the inlet side of the user terminal 100 through the outlet side of the gas boiler 2).

[0022] The inlet end of the second valve group 4 is connected to the water outlet side of the user terminal 100, the first outlet end of the second valve group 4 is connected to the water inlet side of the heat pump assembly 1, and the second outlet end of the second valve group 4 is connected in series with the water inlet side of the gas furnace 2 through the heat pump assembly 1, thereby connecting the water outlet side of the gas furnace 2 to the water inlet side of the user terminal 100.

[0023] In this application, through the coordination of the first valve group 3 and the second valve group 4, the independent start-up and heating of the heat pump component 1 and the gas furnace 2, as well as the series heating of the heat pump component 1 and the gas furnace 2, can be achieved. The gas-electric complementary hot water supply system provided by this application, by setting the first valve group 3 and the second valve group 4 between the heat pump component 1 and the gas furnace 2, realizes the rapid switching of water flow between "direct supply by heat pump", "series heating of heat pump and gas furnace 2", and "direct supply by gas furnace 2". This allows the selection of heat source and water flow path to be automatically optimized according to ambient temperature, outlet water temperature requirements, and load changes. When the heat pump efficiency is high, it can directly supply heat to reduce energy consumption. When the ambient temperature is low or high-temperature outlet water is required, the water can be preheated by the heat pump before entering the gas furnace 2 for enhanced heating, avoiding insufficient water supply caused by the low-temperature attenuation of the heat pump, and reducing energy waste caused by cold water entering the gas furnace 2. This achieves gas-electric complementarity, efficient and stable heating, and lower operating costs, thereby improving the energy efficiency of the system.

[0024] Therefore, this application establishes a collaborative heating mode that features gas-electric complementarity, multi-path adjustability, cascaded energy between heat pumps, and dynamic switching between the heat pump and gas furnace 2. It can automatically select the optimal path based on ambient temperature, user hot water demand, and real-time operating status. By flexibly switching the water flow path through the first valve group 3 and the second valve group 4, the water can be directly heated by the heat pump component 1 before being supplied to the user, or it can further enter the gas furnace 2 for further heating, achieving a balance between high efficiency and energy saving and high-temperature stability. Even in cases of extremely low temperatures or sudden increases in hot water demand, the gas furnace 2 can supplement energy to ensure a constant outlet water temperature. The heat pump component 1 bears most of the basic heating load, while the gas furnace 2 only supplements energy during peak demand or low-temperature conditions, leveraging their respective advantages to reduce overall operating energy consumption.

[0025] like Figure 2 As shown, the heat pump assembly 1 includes: a primary heat pump unit 11, a secondary heat pump unit 12, and a heat exchange unit 13; the primary heat pump unit 11 includes a primary compressor 111, a primary evaporator 112, and a primary throttling valve 113 connected in sequence; the secondary heat pump unit 12 includes a secondary compressor 121, a secondary condenser 122, and a secondary throttling valve 123 connected in sequence; a portion of the heat exchange unit 13 is connected between the primary compressor 111 and the primary throttling valve 113 to form a first refrigerant circulation path; another portion of the heat exchange unit 13 is connected between the secondary compressor 121 and the secondary throttling valve 123 to form a second refrigerant circulation path; the inlet end of the first valve group 3 is connected to the outlet side of the secondary condenser 122; the two outlet ends of the second valve group 4 are respectively connected to the inlet side of the secondary condenser 122 and the heat exchange unit 13; the outlet side of the heat exchange unit 13 is also connected to the inlet side of the gas furnace 2 through a pipe 5.

[0026] Specifically, the primary side of the first-stage compressor 111, the primary side of the first-stage evaporator 112, the primary throttle valve 113, and the heat exchange unit 13 are connected in sequence to form a first refrigerant circulation path; the primary side of the second-stage compressor 121, the primary side of the second-stage condenser 122, the second-stage throttle valve 123, and the heat exchange unit 13 are connected in sequence to form a second refrigerant circulation path, so that the first-stage heat pump unit 11 can supply heat to the second-stage heat pump unit 12 through the heat exchange unit 13. The second valve group 4 is located between the user terminal 100 and the heat pump assembly 1, with its inlet end connected to the water outlet side of the user terminal 100, its first outlet end connected to the secondary side inlet of the secondary condenser 122, and its second outlet end connected to the water inlet side of the heat exchange unit 13. The water outlet side of the heat exchange unit 13 is connected to the gas furnace 2 via a pipe 5. The first valve group 3 is located between the secondary condenser 122 and the user terminal 100, with its inlet end connected to the secondary side outlet of the secondary condenser 122, its first outlet end directly connected to the water inlet side of the user terminal 100, and its second outlet end connected to the water inlet side of the user terminal 100 via the gas furnace 2.

[0027] Therefore, under the coordinated action of the second valve group 4, the first valve group 3, and the pipeline 5, the water effluent from the user terminal 100 can return to the user terminal 100 through the following water paths: The first water path is formed by sequentially connecting the outlet side of the user terminal 100, the inlet end of the second valve group 4, the first outlet end of the second valve group 4, the secondary side of the secondary condenser 122, the inlet end of the first valve group 3, and the first outlet end of the first valve group 3; at this time, the heat pump assembly 1 is turned on (the primary heat pump unit 11, the heat exchange unit 13, and the secondary heat pump unit 12 are all turned on), and the gas furnace 2 is turned off, executing the dual-stage heat pump independent heating mode (e.g., Figure 3 As shown, Figure 3 (The dashed line indicates that the corresponding line is not started); after the heat is supplied by the primary heat pump unit 11, the secondary heat pump unit 12 heats the water at the user end 100, thereby achieving the supply of high-temperature hot water to the user end 100.

[0028] The second water path is formed by sequentially connecting the inlet end of the second valve group 4, the first outlet end of the second valve group 4, the secondary side of the secondary condenser 122, the inlet end of the first valve group 3, the second outlet end of the first valve group 3, and the gas furnace 2; at this time, the heat pump assembly 1 is turned on (the primary heat pump unit 11, the heat exchange unit 13, and the secondary heat pump unit 12 are all turned on), and the gas furnace 2 is turned on, executing the dual-stage heat pump and gas furnace coupled heating mode (e.g., Figure 4 As shown, Figure 4 (The dashed line indicates that the corresponding line is not started). After being heated by the primary heat pump unit 11, the secondary heat pump unit 12 heats the water at the user end 100 for the first time; the hot water obtained from the first heating enters the gas furnace 2 for secondary heating, and is then supplied to the user end 100, thereby realizing the supply of high-temperature hot water to the user end 100.

[0029] The third water path is formed by sequentially connecting the outlet side of user terminal 100, the inlet end of the second valve group 4, the second outlet end of the second valve group 4, the heat exchange unit 13, the pipeline 5, and the gas furnace 2; at this time, only the primary heat pump unit 11 and the heat exchange unit 13 in the heat pump assembly 1 are turned on, the secondary heat pump unit 12 is turned off, and the gas furnace 2 is turned on, executing the primary heat pump and gas furnace coupled heating mode (e.g. Figure 5 As shown, Figure 5 (The dashed line indicates that the corresponding line is not started). Heat exchange unit 13 no longer supplies heat to secondary heat pump unit 12. The water outlet of user terminal 100 enters heat exchange unit 13 and is initially heated by primary heat pump unit 11. The hot water obtained from the initial heating enters gas furnace 2 for secondary heating and is then supplied to the user, thereby achieving the supply of high-temperature hot water to user terminal 100.

[0030] The fourth water path is formed by sequentially connecting the outlet side of user terminal 100, the inlet end of the second valve group 4, the first outlet end of the second valve group 4, the secondary side of the secondary condenser 122, the inlet end of the first valve group 3, the second outlet end of the first valve group 3, and the gas furnace 2; at this time, the heat pump assembly 1 is turned off, the gas furnace 2 is turned on, and the heat pump assembly 1 is only used to supply water flow without heating the water flow, executing the gas furnace independent heating mode (e.g. Figure 6 As shown, Figure 6 (The dashed line indicates that the corresponding line is not activated); the water from user terminal 100 is heated by gas boiler 2 and then returned to user terminal 100, thereby achieving the supply of hot water to user terminal 100.

[0031] It should be noted that the primary heat pump unit 11 can actively supply heat to the secondary heat pump unit 12 through the heat exchange unit 13, thereby solving the problem of severe heat exchange efficiency reduction in existing ordinary single-stage heat pumps at low temperatures.

[0032] This application constructs a heat pump assembly 1 by cascading a primary heat pump unit 11 and a secondary heat pump unit 12 through a heat exchange unit 13. The heat exchange unit 13 transfers energy between the two refrigerant cycles, enabling the primary heat pump to actively provide heat to the secondary heat pump, thereby significantly improving the heating capacity and refrigerant cycle efficiency ratio of the heat pump system under low-temperature conditions. Simultaneously, a water distribution structure consisting of a first valve group 3 and a second valve group 4 is provided, allowing the water outlet from the user end 100 and the secondary condenser 122 to be either directly supplied to the user or sent to the gas furnace 2 for secondary heating, depending on demand. The water outlet from the heat exchange unit 13 can also be directly sent to the gas furnace 2, achieving flexible coupling between the water side and the refrigerant side.

[0033] Therefore, this application establishes a collaborative heating mode that features gas-electric complementarity, multi-path adjustability, cascaded energy between heat pumps, and dynamic switching between the heat pump and gas furnace 2. It can automatically select the optimal path based on ambient temperature, user hot water demand, and real-time operating status. By flexibly switching the water flow path through the first valve group 3 and the second valve group 4, the water can be directly heated by the heat pump component 1 before being supplied to the user, or it can further enter the gas furnace 2 for further heating, achieving a balance between high efficiency and energy saving and high-temperature stability. Even in cases of extremely low temperatures or sudden increases in hot water demand, the gas furnace 2 can supplement energy to ensure a constant outlet water temperature. The heat pump component 1 bears most of the basic heating load, while the gas furnace 2 only supplements energy during peak demand or low-temperature conditions, leveraging their respective advantages to reduce overall operating energy consumption.

[0034] Understandably, a valve can be installed on pipe 5 to control the opening and closing of pipe 5.

[0035] In this application, both the first valve group 3 and the second valve group 4 include three-way valves. For example... Figure 9As shown, both the first valve group 3 and the second valve group 4 can include two two-way valves. For example, a two-way valve 31 can be installed between the water outlet side of the heat pump assembly and the water inlet side of the user end, and a two-way valve 32 can be installed between the water outlet side of the heat pump assembly and the water inlet side of the gas furnace. These two two-way valves constitute the first valve group 3. A two-way valve 41 can be installed between the water outlet side of the user end and the water inlet side of the heat pump assembly; and a two-way valve 42 can be installed between the water outlet side of the user end and the heat pump assembly on the series connection line of the water outlet side of the user end, the heat pump assembly, and the gas furnace. These two two-way valves constitute the second valve group 4.

[0036] The following example uses valve group 3 and valve group 4, both of which include three-way valves: Example 1 in this application like Figure 2 As shown, the heat exchange unit 13 includes a primary condenser 131, a secondary evaporator 133, and a water tank 132; the gas-electric complementary hot water supply system also includes a first connecting pipe 6. The primary condenser 131 is connected to the primary compressor 111 and the primary throttle valve 113 to form a first refrigerant circulation path; the secondary evaporator 133 is connected to the secondary compressor 121 and the secondary throttle valve 123 to form a second refrigerant circulation path; the water inlet side of the water tank 132 is connected to the second valve group 4 and the secondary side outlet of the secondary evaporator 133; the water outlet side of the water tank 132 is connected to the secondary side inlet of the primary condenser 131; the first connecting pipe 6 is connected to the secondary side outlet of the primary condenser 131 and the secondary side inlet of the secondary evaporator 133 to form a first closed-loop water flow path between the primary condenser 131, the secondary evaporator 133, and the water tank 132.

[0037] Specifically, the primary side of the first-stage condenser 131 is connected to the first-stage compressor 111 and the first-stage throttle valve 113 in the first-stage heat pump unit 11, and the primary side of the second-stage evaporator 133 is connected to the second-stage compressor 121 and the second-stage throttle valve 123 in the second-stage heat pump unit 12, respectively; the secondary side of the first-stage condenser 131 is connected to the outlet side of the water tank 132 and the first connecting pipe 6, and the secondary side of the second-stage evaporator 133 is connected to the first connecting pipe 6 and the inlet side of the water tank 132, thereby forming a first closed-loop water flow path between the water tank 132, the first-stage condenser 131, the first connecting pipe 6 and the second-stage evaporator 133.

[0038] In this embodiment, the primary side of the first-stage condenser 131 releases heat to the first closed-loop water flow path, raising the water temperature; the heated water then flows to the second-stage evaporator 133; in the secondary side of the second-stage evaporator 133, this portion of hot water releases heat to the refrigerant in the second-stage heat pump unit 12.

[0039] Meanwhile, the water tank 132, located between the primary condenser 131 and the secondary evaporator 133, can serve as a heat buffer and energy storage unit, stabilizing the heat exchange between the primary heat pump unit 11 and the secondary heat pump unit 12, making the thermal coupling of the two-stage heat pump more stable and reliable. This allows the system to maintain high energy efficiency and stability even at low temperatures, thus overcoming the problems of single heat pump attenuation and high energy consumption of a single gas furnace in existing technologies.

[0040] Based on Embodiment 1 of this application, the gas-electric complementary hot water supply system further includes a flue gas heat exchanger 9; the primary side of the flue gas heat exchanger 9 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 9 is used to connect to the first closed-loop water flow path and the water inlet side of the gas furnace 2 respectively, or to connect to the first closed-loop water flow path.

[0041] In this embodiment, according to the first implementation method, the primary side of the flue gas heat exchanger 9 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 9 is connected to the first closed-loop water flow path and the water inlet side of the gas furnace 2, respectively.

[0042] Specifically, the secondary side of the flue gas heat exchanger 9 is connected to the pipe 5, and the two ends of the pipe 5 are connected to the outlet side of the water tank 132 and the inlet side of the gas furnace 2, respectively. When the primary heat pump and gas furnace coupled heating mode is executed, the water outlet of the user end 100 enters the water tank 132 and is heated for the first time through heat exchange between the water tank 132 and the primary condenser 131. The water flow after the first heating then enters the pipe 5 and the flue gas heat exchanger 9 in sequence, and exchanges heat with the high temperature flue gas discharged from the gas furnace 2 in the flue gas heat exchanger 9 to achieve the second heating of the water flow. Finally, the water flow returns to the user end 100 after the third heating of the gas furnace 2.

[0043] This implementation method is used to perform, as follows: Figure 5 The diagram illustrates a single-stage heat pump coupled with a gas furnace for heating. After initial heating in the first-stage condenser 131, the water flows into the flue gas heat exchanger 9, where it exchanges heat with the high-temperature flue gas discharged from the gas furnace 2. This utilizes the waste heat from the previously discharged flue gas to further raise the water temperature without consuming additional gas, resulting in zero-cost heating. After two heating cycles in the first-stage condenser 131 and the flue gas heat exchanger 9, the water already possesses a high temperature. The gas furnace 2 only needs to provide a small increase in temperature to reach the set temperature, thus significantly reducing gas consumption.

[0044] In this embodiment, according to the second implementation method, the primary side of the flue gas heat exchanger 9 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 9 is connected to the first closed-loop water flow path.

[0045] Specifically, the high-temperature flue gas discharged from the gas furnace 2 enters the primary side of the flue gas heat exchanger 9. The water that has absorbed heat on the secondary side of the flue gas heat exchanger 9 still flows back to the first closed-loop water flow path instead of directly entering the water inlet side of the gas furnace 2. In addition to heat exchange and temperature increase through the first-stage condenser 131, the water in the first closed-loop water flow path also undergoes heat exchange and temperature increase through the flue gas heat exchanger 9, thereby increasing the water temperature of the heat pump assembly 1 during operation and the evaporation temperature of the second-stage evaporator 133.

[0046] This implementation method is used to perform, as follows: Figure 4 The system illustrates a two-stage heat pump coupled with a gas furnace for heating. Utilizing the high-temperature flue gas in the flue gas heat exchanger 9, the system exchanges heat with the water flow in the first closed-loop water circulation path. This allows for the full recovery of high-grade waste heat from the exhaust gas of the gas furnace 2, directly compensating for it in the water tank 132, the heat storage end, thus improving overall heat utilization. The water temperature in the water tank 132 is continuously raised by the flue gas heat exchanger 9, significantly reducing the heating load on the subsequent heat pump assembly 1 or the gas furnace 2, thereby reducing gas consumption. Ultimately, this achieves higher energy efficiency, lower operating costs, and a more stable hot water supply capacity under gas-electric synergy.

[0047] Based on implementation method two, such as Figure 2 , Figure 4 and Figure 5 As shown, the gas-electric complementary hot water supply system also includes a third valve group 8 and a second connecting pipe 7; the third valve group 8 is set in the first closed-loop water flow path and is located between the first-stage condenser 131 and the second-stage evaporator 133; one end of the second connecting pipe 7 is connected to the outlet side of the third valve group 8, and the other end of the second connecting pipe 7 is connected to the secondary side inlet of the second-stage evaporator 133 through the secondary side of the flue gas heat exchanger 9, so as to form a second closed-loop water flow path between the flue gas heat exchanger 9, the secondary side of the second-stage evaporator 133, the water tank 132 and the secondary side of the first-stage condenser 131.

[0048] Specifically, the inlet end of the third valve group 8 is connected to the secondary side outlet of the first-stage condenser 131, the first outlet end of the third valve group 8 is directly connected to the secondary side inlet of the second-stage evaporator 133, and the second outlet end of the third valve group 8 is connected to the secondary side inlet of the second-stage evaporator 133 through the secondary side of the flue gas heat exchanger 9. Thus, by switching and adjusting the third valve group 8, the connection and disconnection between the first closed-loop water flow path and the secondary side of the flue gas heat exchanger 9 can be achieved.

[0049] Based on implementation method two, such as Figure 3 As shown, when the two-stage heat pump independent heating mode is executed, the first outlet end of the second valve group 4 is open, the second outlet end of the second valve group 4 is closed, the first outlet end of the first valve group 3 is open, the second outlet end of the first valve group 3 is closed, the first outlet end of the third valve group 8 is open, the second outlet end of the third valve group 8 is closed, and the valve on the pipeline 5 is closed.

[0050] like Figure 4 As shown, when the dual-stage heat pump and gas furnace coupled heating mode is executed, the first outlet end of the second valve group 4 is opened, the second outlet end of the second valve group 4 is closed, the first outlet end of the first valve group 3 is closed, the second outlet end of the first valve group 3 is opened, the first outlet end of the third valve group 8 is closed, the second outlet end of the third valve group 8 is opened, and the valve on the pipeline 5 is closed.

[0051] like Figure 5 As shown, when the first-level heat pump and gas furnace coupled heating mode is executed, the first outlet end of the second valve group 4 is closed and opened, the second outlet end of the second valve group 4 is opened, the first outlet end and the second outlet end of the first valve group 3 are both closed, the first outlet end of the third valve group 8 is opened, the second outlet end of the third valve group 8 is closed, and the valve on the pipeline 5 is opened.

[0052] like Figure 6 As shown, when the gas furnace is in independent heating mode, the first outlet end of the second valve group 4 is open, the second outlet end of the second valve group 4 is closed, the first outlet end of the first valve group 3 is closed, the second outlet end of the first valve group 3 is open, the first outlet end and the second outlet end of the third valve group 8 are both closed, and the valves on the pipeline 5 are closed.

[0053] like Figure 2 As shown, the third valve group 8 includes a three-way valve; or as... Figure 9 As shown, the third valve group 8 includes two two-way valves 81 and 82; when the third valve group 8 includes two two-way valves, one two-way valve 81 is installed on the first connecting pipe 6, and the other two-way valve 82 is installed on the second connecting pipe 7.

[0054] Example 2 in this application like Figure 7 As shown, the heat exchange unit 13 includes a three-way heat exchanger; the first flow path of the three-way heat exchanger is connected to the first-stage compressor 111 and the first-stage throttling valve 113 respectively to form a first refrigerant circulation flow path; the second flow path of the three-way heat exchanger is connected to the second-stage compressor 121 and the second-stage throttling valve 123 respectively to form a second refrigerant circulation flow path; the third flow path of the three-way heat exchanger is connected to the second valve group 4 and the gas furnace 2 respectively.

[0055] Specifically, the three-way heat exchanger has three flow paths; the first flow path is connected to the first-stage compressor 111 and the first-stage throttling valve 113 to form the first refrigerant circulation flow path; the second flow path is connected to the second-stage compressor 121 and the second-stage throttling valve 123 to form the second refrigerant circulation flow path; and the third flow path is connected to the second outlet end of the second valve group 4 and the gas furnace 2.

[0056] In this embodiment, the three-way heat exchanger integrates the condensation heat release of the primary heat pump unit 11, the evaporation heat absorption of the secondary heat pump unit 12, and the hot water supply circuit of the gas furnace 2 into the same heat exchange structure, achieving efficient coupling of the two heat sources: gas and electricity. Through the three independent flow paths of the three-way heat exchanger, the refrigerant circulation of the primary and secondary heat pumps maintains good thermodynamic independence, avoiding the problems of numerous pipes, high thermal resistance, and low energy coupling efficiency in traditional multi-heat exchanger systems. Therefore, this embodiment not only reduces installation space by reducing the number of heat exchangers in the system, but also reduces heat loss during water circuit switching and energy transfer, improving the overall heating efficiency and response speed when gas and electricity are used for complementary heating. This more effectively solves the technical problems of insufficient heat pump heating capacity and high and unstable energy consumption of a single gas furnace 2 in the prior art.

[0057] In this embodiment, as Figure 7 As shown, the gas-electric complementary hot water supply system also includes a flue gas heat exchanger 9; the primary side of the flue gas heat exchanger 9 is connected to the flue gas outlet of the gas furnace 2, and the secondary side of the flue gas heat exchanger 9 is connected to the third flow path of the three-way heat exchanger.

[0058] Specifically, one end of the third flow path in the three-way heat exchanger is connected to the second outlet end of the second valve group 4, and the other end of the third flow path in the three-way heat exchanger is connected to the gas furnace 2 through the secondary side of the flue gas heat exchanger 9.

[0059] This embodiment organically combines the primary heat pump unit 11, the secondary heat pump unit 12, the three-way heat exchanger, and the flue gas heat exchanger 9 to achieve multi-stage heat utilization and flexible coupling. The primary heat pump unit 11 can provide a stable heat source for the secondary heat pump unit 12. The water flow can be diverted to the gas furnace 2 through the three-way heat exchanger, while the flue gas heat exchanger 9 recovers the waste heat from the exhaust of the gas furnace 2 to preheat the water flow. This ensures a continuous and stable supply of high-temperature hot water under low temperature or high load conditions, while fully leveraging the energy-saving and low-carbon advantages of heat pumps, reducing gas consumption, and improving the overall energy efficiency and economy of the system.

[0060] Based on Embodiment 1 or Embodiment 2 of this application, the operating temperature of the refrigerant in the first refrigerant circulation path is lower than the operating temperature of the refrigerant in the second refrigerant circulation path.

[0061] Specifically, each refrigerant has its optimal operating temperature. Some refrigerants are suitable for absorbing heat in medium- and low-temperature environments and outputting medium-temperature hot water, while others are suitable for high-temperature conditions. Since the first refrigerant circulation path mainly absorbs low-grade heat from the ambient air and has a relatively low evaporation temperature, the first refrigerant circulation path (i.e., the first-stage heat pump unit 11) is suitable for using a refrigerant with a lower operating temperature. On the other hand, the second refrigerant circulation path needs to increase the heat to supply hot water to the user 100, so the second refrigerant circulation path (i.e., the second-stage heat pump unit 12) is suitable for using a refrigerant with a higher operating temperature.

[0062] In this application, the first and second refrigerant circulation paths use different types of refrigerants. The refrigerant in the first circulation path operates at a lower temperature, with a lower boiling point and critical temperature. The refrigerant used in the second circulation path operates at a higher temperature, with a higher critical temperature and high pressure resistance. By using different refrigerants in the two-stage heat pump units, a graded temperature increase can be achieved, ensuring that each stage of the heat pump unit operates within its optimal temperature range. This effectively reduces the compression ratio and improves the overall system energy efficiency and stability.

[0063] The first refrigerant circulation path can use refrigerants such as R410A or R32, which are suitable for operation in the low-temperature range; the second refrigerant circulation path can use refrigerants such as R515B, R134a, or R245fa, which are suitable for operation in the medium- and high-temperature range.

[0064] It should be noted that the above are just examples, and the refrigerants used in two-stage heat pump units are not limited to the examples above.

[0065] For example, when the operating conditions are: ambient temperature 7℃, refrigerant used in the first refrigerant circulation path is R410A, refrigerant used in the second refrigerant circulation path is R515B, the outlet water temperature at user end 100 reaches 40℃, the inlet water temperature at user end 100 can reach 90℃, the combustion efficiency of gas furnace 2 is 89%, the methane volume fraction in the natural gas input to gas furnace 2 is 79.75%, and the natural gas price is 3.5 yuan / Nm³. 3 When the electricity price is 0.5~1 yuan / kWh, the performance comparison results of the two-stage heat pump coupled heating mode and the single-stage heat pump coupled heating mode of this application with the single gas boiler hot water supply system and the single heat pump hot water supply system are shown in the table below: Table 1. Performance Comparison of Existing Single Gas Boiler Hot Water Supply Systems and Single Heat Pump Hot Water Supply Systems with the Two-Stage Heat Pump Coupled Heating Mode and the Single-Stage Heat Pump Coupled Heating Mode of this Application.

[0066] As can be seen from Table 1, from an economic perspective, when the gas price (i.e., the price of natural gas) is 3.5 yuan / Nm³, 3When the electricity price is 0.5 yuan / kWh, both the single heat pump hot water supply system and this application have relatively low production costs per ton of water, while the single gas boiler hot water supply system has the highest production cost. However, when the electricity price rises to 1 yuan / kWh, the production cost per ton of water for the single heat pump hot water supply system increases significantly. At this point, the application shows lower production costs per ton of water compared to both the single gas boiler hot water supply system and the single heat pump hot water supply system. Therefore, the gas-electricity complementary hot water supply system in this application has significant economic advantages over both the single gas boiler hot water supply system and the single heat pump hot water supply system under typical gas-electricity price ratios, and it can achieve optimal economic benefits by adjusting the system integration method under different gas-electricity price ratios.

[0067] One embodiment of this application, such as Figure 8 As shown, the gas-electric complementary hot water supply system also includes a four-way valve 10, which is installed in the first refrigerant circulation path and connected to the first-stage compressor 111, the first-stage condenser 131 and the first-stage evaporator 112 respectively.

[0068] Specifically, the four-way valve 10 is connected to the first refrigerant circulation path, and its four components are respectively connected to the suction port and discharge port of the first-stage compressor 111, the first-stage condenser 131, and the first-stage evaporator 112. During normal heating operation, the high-temperature and high-pressure refrigerant gas discharged from the first-stage compressor 111 is guided to the first-stage condenser 131 for heat release through the four-way valve 10. The liquefied refrigerant enters the first-stage evaporator 112 through the throttling valve, absorbs heat and evaporates, and is then drawn back into the first-stage compressor 111. Thus, the first-stage heat pump unit 11 transfers heat to the second-stage heat pump unit 2 through the heat exchange unit 13.

[0069] When the ambient humidity is high and the temperature is low during operation, causing frost to form on the surface of the first-stage evaporator 112, the heat exchange efficiency of the first-stage heat pump unit 11 will decrease. At this time, the four-way valve 10 will switch to reverse the refrigerant flow, causing the first-stage evaporator 112 to switch to condenser function and the first-stage condenser 131 to switch to evaporator function. The high-temperature refrigerant gas discharged from the first-stage compressor 111 flows to the first-stage evaporator 112 and liquefies in the first-stage evaporator 112. The heat released during the liquefaction process is transferred to the fins of the first-stage evaporator 112, thereby achieving defrosting.

[0070] 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 gas-electric complementary hot water supply system, characterized in that, It includes: Heat pump components; The gas boiler has its outlet side connected to the inlet side at the user's end. The first valve group has its inlet end connected to the outlet side of the heat pump assembly, and both outlet ends connected to the inlet side of the user end, forming two parallel water flow loops; the gas furnace is connected to one of the water flow loops. The second valve assembly is located between the user terminal and the heat pump assembly; the inlet end of the second valve assembly is connected to the water outlet side of the user terminal, one outlet end is connected to the heat pump assembly, and the other outlet end is connected in series with the gas furnace through the heat pump assembly.

2. The gas-electric complementary hot water supply system according to claim 1, characterized in that, The heat pump assembly includes: A primary heat pump unit includes a primary compressor, a primary evaporator, and a primary throttling valve connected in sequence. A two-stage heat pump unit includes a two-stage compressor, a two-stage condenser, and a two-stage throttling valve connected in sequence; the inlet end of the first valve group is connected to the outlet side of the two-stage condenser. The heat exchange unit is connected in part between the primary compressor and the primary throttling valve to form a first refrigerant circulation path; and in part between the secondary compressor and the secondary throttling valve to form a second refrigerant circulation path; the two outlet ends of the second valve group are respectively connected to the water inlet side of the secondary condenser and the heat exchange unit; the water outlet side of the heat exchange unit is also connected to the water inlet side of the gas furnace through a pipeline.

3. The gas-electric complementary hot water supply system according to claim 2, characterized in that, The operating temperature of the refrigerant in the primary heat pump unit is lower than that of the refrigerant in the secondary heat pump unit.

4. The gas-electric complementary hot water supply system according to claim 2, characterized in that, The heat exchange unit includes: A primary condenser, the primary side of which is connected to the primary compressor and the primary expansion valve respectively, to form the first refrigerant circulation path; The primary side of the secondary evaporator is connected to the secondary compressor and the secondary expansion valve respectively to form the second refrigerant circulation path; A water tank; the water inlet side of the water tank is connected to the second valve group and the secondary side outlet of the second-stage evaporator respectively; the water outlet side of the water tank is connected to the secondary side inlet of the first-stage condenser. The first connecting pipe is connected to the secondary side outlet of the first-stage condenser and the secondary side inlet of the second-stage evaporator, respectively, to form a first closed-loop water flow path between the first-stage condenser, the second-stage evaporator and the water tank.

5. The gas-electric complementary hot water supply system according to claim 4, characterized in that, It also includes: A flue gas heat exchanger; 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 used to connect to the first closed-loop water flow path and the water inlet side of the gas furnace, respectively.

6. The gas-electric complementary hot water supply system according to claim 5, characterized in that, One end of the pipeline is connected to the outlet side of the water tank, and the other end is connected to the inlet side of the gas furnace through the secondary side of the flue gas heat exchanger.

7. The gas-electric complementary hot water supply system according to claim 4, characterized in that, It also includes: A flue gas heat exchanger; 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 used to connect to the first closed-loop water flow path.

8. The gas-electric complementary hot water supply system according to claim 7, characterized in that, It also includes: The third valve group is installed on the first closed-loop water flow path and is located between the first-stage condenser and the second-stage evaporator; The second connecting pipe is connected at one end to the outlet side of the third valve group, and at the other end to the secondary side inlet of the secondary evaporator through the secondary side of the flue gas heat exchanger, so as to form a second closed-loop water flow path between the flue gas heat exchanger, the secondary side of the secondary evaporator, the water tank and the secondary side of the primary condenser.

9. The gas-electric complementary hot water supply system according to claim 2, characterized in that, The heat exchange unit includes: A three-way heat exchanger; the first flow path of the three-way heat exchanger is connected to the first-stage compressor and the first-stage throttling valve respectively to form the first refrigerant circulation flow path; the second flow path of the three-way heat exchanger is connected to the second-stage compressor and the second-stage throttling valve respectively to form the second refrigerant circulation flow path; the third flow path of the three-way heat exchanger is connected to the second valve group and the gas furnace respectively.

10. The gas-electric complementary hot water supply system according to claim 9, characterized in that, It also includes: Flue gas heat exchanger; 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 three-way heat exchanger.

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