Solar energy coupling air source heat pump cascade type temperature rise heat supply system

Abstract

The utility model belongs to the technical field of renewable energy utilization, and particularly provides a solar energy coupling air source heat pump cascade type temperature rise heat supply system which comprises a solar energy device, an air source heat pump and a heat supply tail end, the solar energy device is respectively connected with the air source heat pump and the heat supply tail end, and the air source heat pump is connected with the heat supply tail end. The utility model solves the problems of low system energy efficiency ratio and high investment cost in order to achieve the water supply temperature of more than 75 DEG C, the water supply and return temperature difference of more than 25 DEG C, forms an energy complementary heat supply mode, can provide high-temperature hot water of more than 75 DEG C, effectively reduces the operation cost of the system, and reduces the energy consumption of the system. The system can be used as a heat source for urban central heating new projects and urban central heating coal-to-clean energy projects.

Description

Technical Field

[0001] The utility model belongs to the technical field of renewable energy utilization, and in particular relates to a solar energy coupled air source heat pump cascade temperature rising heating system. Background Art

[0002] In order to build a green, economical, efficient, coordinated, applicable and safe clean heating system and win the battle to protect blue skies, various regions have promoted clean heating transformation work.

[0003] Central heating is usually designed with a heating water supply temperature of more than 75°C, and a supply and return water temperature difference of more than 25°C. Heating electric boilers can replace coal-fired boilers to achieve the designed supply and return water temperatures, but the system energy efficiency ratio is low; the outlet water temperature of low-temperature air source heat pumps can only reach 55°C, and other heat sources need to be coupled to replace coal-fired boilers; the outlet water temperature of solar collectors is greatly affected by the weather, and a large heat storage tank needs to be set up, resulting in high system investment.

[0004] The Chinese patent document with publication number CN108302838A discloses a heat storage type solar energy coupled air source heat pump system and its control method, wherein the system includes a compressor, a four-way reversing valve, a gas-liquid separator, a second electronic expansion valve, an indoor heat exchanger, an outdoor heat exchanger and related valves and connecting pipes. Its characteristic is that the system also includes a heat accumulator, a solar collector and a first electronic expansion valve. When the ambient temperature in winter is lower than the switching temperature, the solar energy and the air source heat pump are coupled through the heat accumulator, and the solar energy is directly used for hot water in other seasons, thereby giving full play to the advantages of solar energy. The document uses the heat accumulator as a low-temperature heat source for the system heating process. Since the pressure in the heat accumulator is an intermediate pressure, the compression ratio of the compressor can be greatly reduced, the unit can operate stably, and the heating amount can be greatly increased. When the heat of the heat accumulator is insufficient, the heat pump heat storage process is started to store heat in the heat accumulator. However, the water temperature measured in the document is low and high-temperature hot water above 75°C cannot be provided. Utility Model Content

[0005] The utility model provides a solar energy coupled air source heat pump cascade heating system to overcome the problems in the prior art of achieving a water supply temperature of more than 75°C, a supply and return water temperature difference greater than 25°C, low system energy efficiency ratio and high investment cost.

[0006] To this end, the utility model provides a solar energy coupled air source heat pump cascade heating system, including a solar energy device, an air source heat pump and a heating terminal, the solar energy device is respectively connected to the air source heat pump and the heating terminal, and the air source heat pump is connected to the heating terminal.

[0007] Preferably, the solar device includes a plate heat exchanger, a solar collector, a heat storage tank and a solar heat collection circulation pump, one water outlet of the solar collector is connected to the primary water inlet of the plate heat exchanger through a pipeline, another water outlet of the solar collector is connected to the primary water inlet of the plate heat exchanger through the heat storage tank, the primary water outlet of the plate heat exchanger is connected to the water inlet of the heating end, the water outlet of the heating end is connected to the secondary water inlet of the plate heat exchanger, and the secondary water outlet of the plate heat exchanger is connected to the water inlet of the solar collector through the solar heat collection circulation pump.

[0008] Preferably, the air source heat pump includes an air source heat pump unit, an intermediate heat exchange cycle, an intermediate heat exchange cycle pump and a high-temperature heat pump unit, the outlet of the air source heat pump unit is connected to the primary water inlet of the intermediate heat exchange cycle, the outlet of the primary water of the intermediate heat exchange cycle is connected to the primary water inlet of the high-temperature heat pump unit, the outlet of the primary water of the high-temperature heat pump unit is connected to the inlet of the heating end, the outlet of the heating end is connected to the secondary water inlet of the high-temperature heat pump unit, the outlet of the secondary water of the high-temperature heat pump unit is connected to the secondary water inlet of the intermediate heat exchange cycle through the intermediate heat exchange cycle pump, the outlet of the secondary water of the intermediate heat exchange cycle is connected to the secondary water inlet of the plate heat exchanger, the outlet of the primary water of the plate heat exchanger is connected to the tertiary water inlet of the intermediate heat exchange cycle, and the outlet of the tertiary water of the intermediate heat exchange cycle is connected to the inlet of the air source heat pump unit.

[0009] Preferably, the air source heat pump unit includes an air source heat pump compressor, an air source heat pump air-cooled condenser, an air source heat pump expansion valve and an air source heat pump evaporator, the outlet of the tertiary water of the intermediate heat exchange cycle is connected to the primary inlet of the air source heat pump evaporator, the primary outlet of the air source heat pump evaporator is connected to the secondary inlet of the air source heat pump evaporator through the air source heat pump compressor, the air source heat pump air-cooled condenser and the air source heat pump expansion valve in sequence, and the secondary outlet of the air source heat pump evaporator is connected to the primary water inlet of the intermediate heat exchange cycle.

[0010] Preferably, the high-temperature heat pump unit includes a high-temperature heat pump compressor, a high-temperature heat pump condenser, a high-temperature heat pump expansion valve and a high-temperature heat pump evaporator. The primary water outlet of the intermediate heat exchange cycle is connected to the primary inlet of the high-temperature heat pump condenser. The primary outlet of the high-temperature heat pump condenser is connected to the water inlet of the heating end through the high-temperature heat pump expansion valve, the primary inlet of the high-temperature heat pump evaporator, and the primary outlet of the high-temperature heat pump evaporator in sequence. The water outlet of the heating end is once connected to the secondary inlet of the high-temperature heat pump evaporator, the secondary outlet of the high-temperature heat pump evaporator, the high-temperature heat pump compressor, the secondary inlet of the high-temperature heat pump condenser and the secondary outlet of the high-temperature heat pump condenser.

[0011] Preferably, the intermediate heat exchange cycle includes pipeline one, pipeline two, pipeline three, pipeline four and pipeline five. The secondary outlet of the air source heat pump evaporator is connected to the primary inlet of the high-temperature heat pump condenser through pipeline one. The outlet end of the intermediate heat exchange cycle pump is connected to the secondary water inlet of the plate heat exchanger through pipeline two. The primary water outlet of the plate heat exchanger is connected to the primary inlet of the air source heat pump evaporator through pipeline three. Pipeline four is connected between pipeline two and pipeline three, and pipeline five is connected between pipeline one and pipeline three.

[0012] Preferably, the pipeline one is provided with a switch valve one, the pipeline two is provided with a switch valve two, and the pipeline three is provided with switch valve three and switch valve four in sequence; one end of the pipeline four is connected to the pipeline three between the switch valve three and the switch valve four, and the other end of the pipeline four is connected to the pipeline two between the switch valve two and the intermediate heat exchange circulation pump; one end of the pipeline five is connected to the pipeline one between the switch valve one and the high-temperature heat pump condenser, and the other end of the pipeline five is connected to the pipeline three between the switch valve four and the pipeline four; the pipeline five is provided with a switch valve five, and the pipeline four is provided with a switch valve six.

[0013] Preferably, the plate heat exchanger also includes heat exchange pipeline one and heat exchange pipeline two, and the heating end also includes a heating pipeline and a heat recovery pipeline; the primary water outlet of the plate heat exchanger is connected to the heating pipeline through heat exchange pipeline one, and the heat recovery pipeline is connected to the secondary water inlet of the plate heat exchanger through heat exchange pipeline two; the primary outlet of the high-temperature heat pump evaporator is connected to the inlet of the heating end through the heating pipeline, and the outlet of the heating end is connected to the secondary inlet of the high-temperature heat pump evaporator through the heating pipeline.

[0014] Preferably, the heat exchange pipeline one is provided with a switch valve seven, the heat exchange pipeline two is provided with a switch valve eight, the heating pipeline is provided with a switch valve nine, the heat return pipeline is provided with a switch valve ten, the heat exchange pipeline one is connected to the heating pipeline between the switch valve nine and the heating end, the heat exchange pipeline two is connected to the heat return pipeline between the switch valve ten and the heating end; the heat return pipeline between the switch valve ten and the heating end is provided with a terminal heating circulation pump.

[0015] Preferably, a heat collecting pipeline 1, a heat collecting pipeline 2 and a heat collecting pipeline 3 are connected between the solar collector and the plate heat exchanger, the solar collector is connected to the inlet 1 of the plate heat exchanger through the heat collecting pipeline 1, the heat collecting pipeline 2 is connected between the heat collecting pipeline 1 and the inlet of the hot water storage tank, and the outlet of the hot water storage tank is connected to the heat collecting pipeline 1 through the heat collecting pipeline 3; the heat collecting pipeline 1 between the heat collecting pipeline 2 and the heat collecting pipeline 3 is connected with a switch valve 11, the heat collecting pipeline 2 is connected with a switch valve 12, and the heat collecting pipeline 3 is connected with a switch valve 13.

[0016] Beneficial effects of the utility model:

[0017] 1. The solar energy coupled air source heat pump cascade heating system provided by the utility model comprises a solar energy device, an air source heat pump and a heating terminal. The system couples the solar energy device and the air source heat pump. The system monitors the outlet water temperature of the solar water heater.

[0018] When the solar device can reach the supply and return water temperature and meet the terminal heating demand, solar hot water direct heating is adopted; effectively reducing the system operation cost;

[0019] When the solar device cannot reach the supply and return water temperature due to the weather and can only provide partial heat, the solar device is used to provide low-temperature hot water, which is then heated by the air source heat pump for heating; the solar device is used as a primary low-temperature heat source (supply and return water temperature 30℃ / 20℃), and the secondary high-temperature heat pump unit is used to heat the heating hot water to the required supply and return water temperature (supply water temperature above 75℃, supply and return water temperature difference greater than 25℃), which can meet the terminal forms with different temperature requirements such as floor heating, radiator, and hot air heating;

[0020] When the solar energy device cannot provide heat due to weather conditions, an air source heat pump is used to heat the hot water for heating; the heating water is heated to the required supply and return water temperature (the supply water temperature is above 75°C, and the supply and return water temperature difference is greater than 25°C);

[0021] This system forms an energy-complementary heating mode, effectively reducing system operating costs; it can be used as a heat source for urban centralized heating projects, and the system's comprehensive energy efficiency ratio COP is greater than 1.8, which is higher than that of electric boilers (energy efficiency ratio 0.95) heating projects, saving electricity.

[0022] 2. The solar energy coupled air source heat pump cascade heating system provided by the utility model comprises an air source heat pump unit, an intermediate heat exchange cycle, an intermediate heat exchange cycle pump and a high temperature heat pump unit. The air source heat pump of this structure has a high energy efficiency ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be described in further detail below in conjunction with the accompanying drawings.

[0024] Figure 1 It is a structural diagram of a solar energy coupled air source heat pump cascade heating system.

[0025] Description of reference numerals: 1. air source heat pump unit; 2. intermediate heat exchange cycle; 3. intermediate heat exchange circulation pump; 4. high temperature heat pump unit; 5. heating terminal; 6. plate heat exchanger; 7. solar collector; 8. hot water storage tank; 9. solar collector circulation pump;

[0026] 11. Air source heat pump compressor; 12. Air source heat pump air-cooled condenser; 13. Air source heat pump expansion valve; 14. Air source heat pump evaporator;

[0027] 21. Switch valve three; 22. Switch valve two; 23. Switch valve six; 24. Switch valve four; 25. Switch valve five; 26. Switch valve one;

[0028] 41. High temperature heat pump compressor; 42. High temperature heat pump condenser; 43. High temperature heat pump expansion valve; 44. High temperature heat pump evaporator;

[0029] 51. On-off valve eight; 52. On-off valve seven; 53. On-off valve nine; 54. On-off valve ten; 55. Terminal heating circulation pump;

[0030] 81. On-off valve thirteen; 82. On-off valve twelve; 83. On-off valve eleven. DETAILED DESCRIPTION

[0031] The principles and features of the present utility model are described below in conjunction with the accompanying drawings.

[0032] Embodiment 1:

[0033] like Figure 1 As shown, a solar energy coupled air source heat pump cascade heating system includes a solar energy device, an air source heat pump and a heating terminal 5, the solar energy device is connected to the air source heat pump and the heating terminal 5 respectively, and the air source heat pump is connected to the heating terminal 5.

[0034] Specifically, the system couples the solar device and the air source heat pump. The system monitors the outlet water temperature of the solar hot water.

[0035] When the solar device can reach the supply and return water temperature and meet the terminal heating demand, solar hot water direct heating is adopted; effectively reducing the system operation cost;

[0036] When the solar device cannot reach the supply and return water temperature due to the weather and can only provide partial heat, the solar device is used to provide low-temperature hot water, which is then heated by the air source heat pump for heating; the solar device is used as a primary low-temperature heat source (supply and return water temperature 30℃ / 20℃), and the secondary high-temperature heat pump unit 4 heats the heating hot water to the required supply and return water temperature (supply water temperature above 75℃, supply and return water temperature difference greater than 25℃), which can meet the terminal forms of different temperature requirements such as floor heating, radiator, hot air heating, etc.

[0037] When the solar energy device cannot provide heat due to weather conditions, an air source heat pump is used to heat the hot water for heating; the heating water is heated to the required supply and return water temperature (the supply water temperature is above 75°C, and the supply and return water temperature difference is greater than 25°C);

[0038] This system forms an energy-complementary heating mode, effectively reducing system operating costs; it can be used as a heat source for urban centralized heating projects, and the system's comprehensive energy efficiency ratio COP is greater than 1.8, which is higher than that of electric boilers (energy efficiency ratio 0.95) heating projects, saving electricity.

[0039] Embodiment 2:

[0040] On the basis of Example 1, the solar energy device includes a plate heat exchanger 6, a solar collector 7, a heat storage tank 8 and a solar heat collection circulation pump 9. One water outlet of the solar collector 7 is connected to the primary water inlet of the plate heat exchanger 6 through a pipeline, and another water outlet of the solar collector 7 is connected to the primary water inlet of the plate heat exchanger 6 through the heat storage tank 8. The primary water outlet of the plate heat exchanger 6 is connected to the water inlet of the heating terminal 5, and the water outlet of the heating terminal 5 is connected to the secondary water inlet of the plate heat exchanger 6. The secondary water outlet of the plate heat exchanger 6 is connected to the water inlet of the solar collector 7 through the solar heat collection circulation pump 9.

[0041] Specifically, in the initial stage of heating, when the solar collector can reach the supply and return water temperature (75℃ / 50℃) to meet the terminal heating demand and there is surplus, solar hot water direct heating + heat storage is adopted.

[0042] During the day, the solar heat collection circulation pump 9 provides circulation power, the hot water is heated by the solar heat collector 7, the heat is stored in the hot water storage tank 8, the heat is exchanged through the plate heat exchanger 6, and the hot water after heat exchange is directly supplied to the terminal 5 for heating. At night, the hot water in the hot water storage tank 8 is used for heating.

[0043] In the initial stage of heating, when the solar collector 7 can reach the supply and return water temperature (75℃ / 50℃) to meet the terminal heating demand, solar hot water direct heating is adopted; the solar heating cycle uses the solar heat collection circulation pump 9 to provide circulation power, the hot water is heated by the solar collector 7, the heat is exchanged by the plate heat exchanger 6, and the hot water after heat exchange is directly supplied to the terminal 5 for heating.

[0044] The system adopts solar energy + hot water storage tank 8, and can use solar hot water in weather with good solar radiation, effectively reducing the system operation cost.

[0045] Embodiment 3:

[0046] On the basis of Example 2, the air source heat pump includes an air source heat pump unit 1, an intermediate heat exchange cycle 2, an intermediate heat exchange cycle pump 3 and a high-temperature heat pump unit 4, the outlet of the air source heat pump unit 1 is connected to the primary water inlet of the intermediate heat exchange cycle 2, the primary water outlet of the intermediate heat exchange cycle 2 is connected to the primary water inlet of the high-temperature heat pump unit 4, the primary water outlet of the high-temperature heat pump unit 4 is connected to the inlet of the heating terminal 5, the outlet of the heating terminal 5 is connected to the secondary water inlet of the high-temperature heat pump unit 4, the secondary water outlet of the high-temperature heat pump unit 4 is connected to the secondary water inlet of the intermediate heat exchange cycle 2 through the intermediate heat exchange cycle pump 3, the secondary water outlet of the intermediate heat exchange cycle 2 is connected to the secondary water inlet of the plate heat exchanger 6, the primary water outlet of the plate heat exchanger 6 is connected to the tertiary water inlet of the intermediate heat exchange cycle 2, and the tertiary water outlet of the intermediate heat exchange cycle 2 is connected to the inlet of the air source heat pump unit 1.

[0047] When solar energy can only meet part of the heating demand, hot water is exchanged for part of the heating hot water through the plate heat exchanger 6, and then heated up by the air source heat pump unit 1 to produce 30℃ / 20℃, and then absorbed by the high-temperature heat pump unit 4, and heated up to 75℃ / 50℃ again before being supplied to the terminal 5 for heating.

[0048] When the solar collector 7 is unable to provide heat due to weather conditions, all the hot water is heated by the air source heat pump unit 1 to produce 30℃ / 20℃, and then absorbed by the high temperature heat pump unit 4, and heated again to 75℃ / 50℃ before being supplied to the terminal 5 for heating.

[0049] The air source heat pump of this structure has high energy efficiency. The system adopts a two-stage heating cascade system, that is, the solar collector 7 is used as the first-level low-temperature heat source (supply and return water temperature 30℃ / 20℃), and the high-temperature heat pump unit 4 is used as the second-level high-temperature heat source to heat the heating hot water to the required supply and return water temperature (supply water temperature above 75℃, supply and return water temperature difference greater than 25℃), forming an energy complementary heating mode, which can meet the terminal forms of different temperature requirements such as floor heating, radiator, hot air heating, etc.

[0050] Preferably, the air source heat pump unit 1 includes an air source heat pump compressor 11, an air source heat pump air-cooled condenser 12, an air source heat pump expansion valve 13 and an air source heat pump evaporator 14, the tertiary water outlet of the intermediate heat exchange cycle 2 is connected to the primary inlet of the air source heat pump evaporator 14, the primary outlet of the air source heat pump evaporator 14 is connected to the secondary inlet of the air source heat pump evaporator 14 through the air source heat pump compressor 11, the air source heat pump air-cooled condenser 12 and the air source heat pump expansion valve 13 in sequence, and the secondary outlet of the air source heat pump evaporator 14 is connected to the primary water inlet of the intermediate heat exchange cycle 2.

[0051] Specifically, the working process of the air source heat pump unit 1 is as follows: the state before entering the air source heat pump evaporator 14 to absorb heat: low-temperature and low-pressure liquid → absorbing heat from the air through the air source heat pump evaporator 14 (gasification) → the refrigerant becomes a low-temperature and low-pressure gas → compressed by the air source heat pump compressor 11 → becomes a high-temperature and high-pressure gas → exchanges heat with water through the air source heat pump air-cooled condenser 12 → becomes a low-temperature and high-pressure liquid → throttled by the air source heat pump expansion valve 13 → becomes a low-temperature and low-pressure liquid → enters the air source heat pump evaporator 14 to repeat the process; the air source heat pump unit 1, as a highly efficient heat collection and heat transfer device, can convert the electricity consumed by the air source heat pump compressor 11 into thermal energy within five times, and the energy-saving effect is very significant.

[0052] Preferably, the high-temperature heat pump unit 4 includes a high-temperature heat pump compressor 41, a high-temperature heat pump condenser 42, a high-temperature heat pump expansion valve 43 and a high-temperature heat pump evaporator 44, the primary water outlet of the intermediate heat exchange cycle 2 is connected to the primary inlet of the high-temperature heat pump condenser 42, the primary outlet of the high-temperature heat pump condenser 42 is connected to the water inlet of the heating terminal 5 through the high-temperature heat pump expansion valve 43, the primary inlet of the high-temperature heat pump evaporator 44, and the primary outlet of the high-temperature heat pump evaporator 44 in sequence, and the water outlet of the heating terminal 5 is once connected to the secondary inlet of the high-temperature heat pump evaporator 44, the secondary outlet of the high-temperature heat pump evaporator 44, the high-temperature heat pump compressor 41, the secondary inlet of the high-temperature heat pump condenser 42 and the secondary outlet of the high-temperature heat pump condenser 42.

[0053] Specifically, the low-temperature and low-pressure refrigerant gas is compressed into a high-temperature and high-pressure gas by the high-temperature heat pump compressor 41. The high-temperature and high-pressure refrigerant gas from the high-temperature heat pump compressor 41 flows through the high-temperature heat pump condenser 42, and uses water to continuously release heat to the outside world, and condenses into a medium-temperature and high-pressure refrigerant liquid; the medium-temperature and high-pressure refrigerant liquid from the high-temperature heat pump condenser 42 is throttled by the high-temperature heat pump expansion valve 43 and becomes a low-temperature and low-pressure refrigerant liquid; the low-temperature and low-pressure refrigerant liquid from the high-temperature heat pump expansion valve 43 flows through the high-temperature heat pump evaporator 44, and uses wind or water to continuously absorb heat from the room, and evaporates into a low-temperature and low-pressure refrigerant gas. It is collected by the high-temperature heat pump unit 4 and converted into water above 85 degrees for heating use, which can directly replace traditional coal-fired boilers and is the best choice for achieving industrial energy saving, consumption reduction and efficiency improvement.

[0054] Preferably, the intermediate heat exchange cycle 2 includes pipeline one, pipeline two, pipeline three, pipeline four and pipeline five. The secondary outlet of the air source heat pump evaporator 14 is connected to the primary inlet of the high-temperature heat pump condenser 42 through pipeline one. The outlet end of the intermediate heat exchange cycle pump 3 is connected to the secondary water inlet of the plate heat exchanger 6 through pipeline two. The primary water outlet of the plate heat exchanger 6 is connected to the primary inlet of the air source heat pump evaporator 14 through pipeline three. Pipeline four is connected between pipeline two and pipeline three, and pipeline five is connected between pipeline one and pipeline three.

[0055] Specifically, the intermediate heat exchange cycle 2 of the structure is simple in structure and can better realize the heat exchange cycle.

[0056] Preferably, the pipeline one is provided with a switch valve one 26, the pipeline two is provided with a switch valve two 22, and the pipeline three is provided with a switch valve three 21 and a switch valve four 24 in sequence; one end of the pipeline four is connected to the pipeline three between the switch valve three 21 and the switch valve four 24, and the other end of the pipeline four is connected to the pipeline two between the switch valve two 22 and the intermediate heat exchange circulation pump 3; one end of the pipeline five is connected to the pipeline one between the switch valve one 26 and the high-temperature heat pump condenser 42, and the other end of the pipeline five is connected to the pipeline three between the switch valve four 24 and the pipeline four; the pipeline five is provided with a switch valve five 25, and the pipeline four is provided with a switch valve six 23.

[0057] Specifically, by controlling the opening and closing of each switch valve (switch valve 1 26, switch valve 2 22, switch valve 3 21, switch valve 4 24, switch valve 5 25 and switch valve 6 23), heat supply can be better achieved.

[0058] Preferably, the plate heat exchanger 6 also includes heat exchange pipeline 1 and heat exchange pipeline 2, and the heating terminal 5 also includes a heating pipeline and a heat recovery pipeline; the primary water outlet of the plate heat exchanger 6 is connected to the heating pipeline through heat exchange pipeline 1, and the heat recovery pipeline is connected to the secondary water inlet of the plate heat exchanger 6 through heat exchange pipeline 2; the primary outlet of the high-temperature heat pump evaporator 44 is connected to the inlet of the heating terminal 5 through the heating pipeline, and the outlet of the heating terminal 5 is connected to the secondary inlet of the high-temperature heat pump evaporator 44 through the heat supply pipeline.

[0059] Specifically, water supply and water return are achieved through a heating pipeline and a heat return pipeline.

[0060] Preferably, the heat exchange pipeline one is provided with a switch valve seven 52, the heat exchange pipeline two is provided with a switch valve eight 51, the heating pipeline is provided with a switch valve nine 53, the heat return pipeline is provided with a switch valve ten 54, the heat exchange pipeline one is connected to the heating pipeline between the switch valve nine 53 and the heating terminal 5, the heat exchange pipeline two is connected to the heat return pipeline between the switch valve ten 54 and the heating terminal 5; the heat return pipeline between the switch valve ten 54 and the heating terminal 5 is provided with a terminal heating circulation pump 55.

[0061] Specifically, by controlling the switch valves (switch valve seven 52, switch valve eight 51, switch valve nine 53 and switch valve ten 54), the supply ratio of each energy source can be better adjusted.

[0062] Preferably, a heat collecting pipeline 1, a heat collecting pipeline 2 and a heat collecting pipeline 3 are connected between the solar collector 7 and the plate heat exchanger 6. The solar collector 7 is connected to the inlet 1 of the plate heat exchanger 6 through the heat collecting pipeline 1, the heat collecting pipeline 2 is connected between the heat collecting pipeline 1 and the inlet of the hot water storage tank 8, and the outlet of the hot water storage tank 8 is connected to the heat collecting pipeline 1 through the heat collecting pipeline 3; the heat collecting pipeline 1 between the heat collecting pipeline 2 and the heat collecting pipeline 3 is connected with a switch valve 11 83, the heat collecting pipeline 2 is connected with a switch valve 12 82, and the heat collecting pipeline 3 is connected with a switch valve 13 81.

[0063] Specifically, by controlling the switch valves (switch valve eleven 83, switch valve twelve 82, switch valve thirteen 81), the supply ratio of each energy source can be better adjusted.

[0064] The working principle of the utility model is:

[0065] In the initial stage of heating, when the solar collector can reach the supply and return water temperature (75℃ / 50℃) to meet the terminal heating demand and there is surplus, solar hot water direct heating + heat storage is adopted. During the day, the solar heat collection circulation pump 9 provides circulation power, the hot water is heated by the solar collector 7, the switch valve 11 83 is opened, the switch valve 13 81 is opened, and the switch valve 12 82 is opened, the hot water supply and storage are combined, and the heat storage is stored in the hot water storage tank 8, the heat is exchanged through the plate heat exchanger 6, and the hot water after heat exchange is directly supplied to the terminal 5 for heating, and the circulation power is provided by the terminal heating circulation pump 55, the switch valve 8 51 is opened, the switch valve 7 52 is opened, the switch valve 9 53 is closed, the switch valve 10 54 is closed, the switch valve 3 21 is closed, and the switch valve 2 22 is closed. At night, the hot water in the hot water storage tank 8 is used for heating.

[0066] In the initial stage of heating, when the solar collector 7 can reach the supply and return water temperature (75℃ / 50℃) to meet the terminal heating demand, solar hot water direct heating is adopted; the solar heating cycle uses the solar heat collection circulation pump 9 to provide circulation power, the hot water is heated by the solar collector 7, the switch valve 11 83 is opened, the switch valve 13 81 is closed, and the switch valve 12 82 is closed. The heat is exchanged through the plate heat exchanger 6, and the hot water after heat exchange is directly supplied to the terminal 5 for heating. The terminal heating circulation pump 55 provides circulation power, the switch valve eight 51 is opened, the switch valve seven 52 is opened, the switch valve nine 53 is closed, the switch valve ten 54 is closed, the switch valve three 21 is closed, and the switch valve two 22 is closed.

[0067] When solar energy can only meet part of the heating demand, hot water is exchanged for part of the heating hot water through the plate heat exchanger 6, the switch valve eight 51 is closed, the switch valve seven 52 is closed, the switch valve three 21 is opened, the switch valve two 22 is opened, the switch valve six 23 is closed, the switch valve four 24 is opened, the switch valve five 25 is closed, and the switch valve one 26 is opened. The hot water is then heated by the air source heat pump unit 1 to produce 30℃ / 20℃, and the high temperature heat pump unit 4 absorbs heat, and the temperature is raised to 75℃ / 50℃ again before being supplied to the terminal 5 for heating.

[0068] When the solar collector 7 cannot provide heat due to the weather, the switch valve three 21 is closed, the switch valve two 22 is closed, the switch valve six 23 is opened, the switch valve four 24 is opened, the switch valve five 25 is closed, and the switch valve one 26 is opened. All the hot water is heated by the air source heat pump unit 1 to produce 30℃ / 20℃, and then absorbed by the high-temperature heat pump unit 4. The temperature is raised to 75℃ / 50℃ again and then supplied to the terminal 5 for heating.

[0069] In the description of the present invention, it should be understood that if a term indicates an orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention.

[0070] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are identical or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A solar energy coupled air source heat pump cascade heating system, characterized in that: It comprises a solar device, an air source heat pump and a heating terminal (5), the solar device is connected to the air source heat pump and the heating terminal (5) respectively, and the air source heat pump is connected to the heating terminal (5); The air source heat pump comprises an air source heat pump unit (1), an intermediate heat exchange cycle (2), an intermediate heat exchange cycle pump (3) and a high temperature heat pump unit (4); the outlet of the air source heat pump unit (1) is connected to the primary water inlet of the intermediate heat exchange cycle (2); the outlet of the primary water of the intermediate heat exchange cycle (2) is connected to the primary water inlet of the high temperature heat pump unit (4); the outlet of the primary water of the high temperature heat pump unit (4) is connected to the inlet of the heating terminal (5); the outlet of the heating terminal (5) is connected to the high temperature The secondary water inlet of the heat pump unit (4) and the secondary water outlet of the high-temperature heat pump unit (4) are connected to the secondary water inlet of the intermediate heat exchange cycle (2) through the intermediate heat exchange cycle pump (3), the secondary water outlet of the intermediate heat exchange cycle (2) is connected to the secondary water inlet of the plate heat exchanger (6), the primary water outlet of the plate heat exchanger (6) is connected to the tertiary water inlet of the intermediate heat exchange cycle (2), and the tertiary water outlet of the intermediate heat exchange cycle (2) is connected to the inlet of the air source heat pump unit (1); The air source heat pump unit (1) comprises an air source heat pump compressor (11), an air source heat pump air-cooled condenser (12), an air source heat pump expansion valve (13) and an air source heat pump evaporator (14); the tertiary water outlet of the intermediate heat exchange cycle (2) is connected to the primary inlet of the air source heat pump evaporator (14); the primary outlet of the air source heat pump evaporator (14) is connected to the secondary inlet of the air source heat pump evaporator (14) via the air source heat pump compressor (11), the air source heat pump air-cooled condenser (12) and the air source heat pump expansion valve (13) in sequence; and the secondary outlet of the air source heat pump evaporator (14) is connected to the primary water inlet of the intermediate heat exchange cycle (2).

2. The solar-coupled air-source heat pump cascade heating system according to claim 1, characterized in that: The solar device comprises a plate heat exchanger (6), a solar thermal collector (7), a heat storage tank (8) and a solar thermal collection circulation pump (9); one water outlet of the solar thermal collector (7) is connected to a primary water inlet of the plate heat exchanger (6) through a pipeline; another water outlet of the solar thermal collector (7) is connected to the primary water inlet of the plate heat exchanger (6) through the heat storage tank (8); the primary water outlet of the plate heat exchanger (6) is connected to a water inlet of a heating terminal (5); the water outlet of the heating terminal (5) is connected to a secondary water inlet of the plate heat exchanger (6); and the secondary water outlet of the plate heat exchanger (6) is connected to the water inlet of the solar thermal collector (7) through the solar thermal collection circulation pump (9).

3. The solar-coupled air-source heat pump cascade heating system according to claim 2, characterized in that: The high-temperature heat pump unit (4) comprises a high-temperature heat pump compressor (41), a high-temperature heat pump condenser (42), a high-temperature heat pump expansion valve (43) and a high-temperature heat pump evaporator (44); the primary water outlet of the intermediate heat exchange cycle (2) is connected to the primary inlet of the high-temperature heat pump condenser (42); the primary outlet of the high-temperature heat pump condenser (42) is connected to the water inlet of the heating terminal (5) through the high-temperature heat pump expansion valve (43), the primary inlet of the high-temperature heat pump evaporator (44) and the primary outlet of the high-temperature heat pump evaporator (44) in sequence; the water outlet of the heating terminal (5) is connected to the secondary inlet of the high-temperature heat pump evaporator (44), the secondary outlet of the high-temperature heat pump evaporator (44), the high-temperature heat pump compressor (41), the secondary inlet of the high-temperature heat pump condenser (42) and the secondary outlet of the high-temperature heat pump condenser (42) in one step.

4. The solar-coupled air-source heat pump cascade heating system according to claim 3, characterized in that: The intermediate heat exchange cycle (2) comprises pipeline 1, pipeline 2, pipeline 3, pipeline 4 and pipeline 5. The secondary outlet of the air source heat pump evaporator (14) is connected to the primary inlet of the high-temperature heat pump condenser (42) through pipeline 1. The outlet end of the intermediate heat exchange cycle pump (3) is connected to the secondary water inlet of the plate heat exchanger (6) through pipeline 2. The primary water outlet of the plate heat exchanger (6) is connected to the primary inlet of the air source heat pump evaporator (14) through pipeline 3. Pipeline 4 is connected between pipeline 2 and pipeline 3, and pipeline 5 is connected between pipeline 1 and pipeline 3.

5. The solar-coupled air-source heat pump cascade heating system according to claim 4, characterized in that: The pipeline 1 is provided with a switch valve 1 (26), the pipeline 2 is provided with a switch valve 2 (22), and the pipeline 3 is provided with a switch valve 3 (21) and a switch valve 4 (24) in sequence; one end of the pipeline 4 is connected to the pipeline 3 between the switch valve 3 (21) and the switch valve 4 (24), and the other end of the pipeline 4 is connected to the pipeline 2 between the switch valve 2 (22) and the intermediate heat exchange circulation pump (3); one end of the pipeline 5 is connected to the pipeline 1 between the switch valve 1 (26) and the high-temperature heat pump condenser (42), and the other end of the pipeline 5 is connected to the pipeline 3 between the switch valve 4 (24) and the pipeline 4; the pipeline 5 is provided with a switch valve 5 (25), and the pipeline 4 is provided with a switch valve 6 (23).

6. The solar-coupled air-source heat pump cascade heating system according to claim 5, characterized in that: The plate heat exchanger (6) further comprises a heat exchange pipeline 1 and a heat exchange pipeline 2, and the heat supply terminal (5) further comprises a heat supply pipeline and a heat return pipeline; the primary water outlet of the plate heat exchanger (6) is connected to the heat supply pipeline via the heat exchange pipeline 1, and the heat return pipeline is connected to the secondary water inlet of the plate heat exchanger (6) via the heat exchange pipeline 2; the primary outlet of the high-temperature heat pump evaporator (44) is connected to the inlet of the heat supply terminal (5) via the heat supply pipeline, and the outlet of the heat supply terminal (5) is connected to the secondary inlet of the high-temperature heat pump evaporator (44) via the heat return pipeline.

7. The solar-coupled air-source heat pump cascade heating system according to claim 6, characterized in that: The heat exchange pipeline one is provided with a switch valve seven (52), the heat exchange pipeline two is provided with a switch valve eight (51), the heat supply pipeline is provided with a switch valve nine (53), and the heat return pipeline is provided with a switch valve ten (54). The heat exchange pipeline one is connected to the heat supply pipeline between the switch valve nine (53) and the heat supply terminal (5), and the heat exchange pipeline two is connected to the heat return pipeline between the switch valve ten (54) and the heat supply terminal (5); and the heat return pipeline between the switch valve ten (54) and the heat supply terminal (5) is provided with a terminal heat supply circulation pump (55).

8. The solar-coupled air-source heat pump cascade heating system according to claim 7, characterized in that: A heat collecting pipeline 1, a heat collecting pipeline 2 and a heat collecting pipeline 3 are provided between the solar collector (7) and the plate heat exchanger (6); the solar collector (7) is connected to an inlet 1 of the plate heat exchanger (6) via the heat collecting pipeline 1; the heat collecting pipeline 2 is connected between the heat collecting pipeline 1 and the inlet of the hot water storage tank (8); the outlet of the hot water storage tank (8) is connected to the heat collecting pipeline 1 via the heat collecting pipeline 3; an on-off valve 11 (83) is provided on the heat collecting pipeline 1 between the heat collecting pipeline 2 and the heat collecting pipeline 3; an on-off valve 12 (82) is provided on the heat collecting pipeline 2; and an on-off valve 13 (81) is provided on the heat collecting pipeline 3.

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