A low ambient temperature air source heat pump system and method for constant temperature hot water supply

Abstract

The present invention relates to a low ambient temperature air source heat pump system and method for constant temperature hot water supply. The present invention includes a compressor, a three-way valve 1, a gas-liquid separator, a user side heat exchanger, a one-way valve 1, a one-way valve 2, a one-way valve 3, a one-way valve 4, a liquid reservoir, an economizer, a throttling element 1, a throttling element 2, a three-way valve 2, a three-way valve 3, a fan 1, a fin heat exchanger 1, a fan 2, a fin heat exchanger 2, a three-way valve 4, and a three-way valve 5; the high temperature and high pressure refrigerant discharged from the compressor releases heat through the three-way valve and the user side heat exchanger, and then is diverted into the fin heat exchanger for further cooling, and finally merged into the liquid reservoir; after the refrigerant output from the liquid reservoir is supercooled by the economizer, a part of it enters the economizer after throttling to evaporate and absorb heat, and the other part absorbs air heat through the fin heat exchanger and returns to the compressor to form a cycle; when the fin heat exchanger reaches the defrosting condition, it is quickly defrosted. It is suitable for low temperature environments and meets the needs of efficient and energy-saving heating.

Description

Technical Field

[0001] The present invention relates to the technical field of air source heat pumps, and in particular to a low ambient temperature air source heat pump system and method for constant temperature hot water supply. Background Art

[0002] With the emphasis on environmental protection, energy saving and low carbon have been deeply rooted in people's hearts. As an energy-saving technology, air source heat pumps have been widely used in urban heating and domestic hot water. However, in cold areas, air source heat pumps have too low evaporation temperature and too high condensation temperature, which leads to excessive compression ratio of compressor suction and exhaust, hidden danger of mechanical damage to the compressor, or failure to work normally due to too high exhaust temperature of the compressor, thus reducing the adaptability of air source heat pumps.

[0003] After the air source heat pump unit has been working for a period of time in winter, because the temperature of the fin heat exchanger on the environment side is lower than the outdoor environment temperature, under the temperature difference and the action of the outdoor fan, the water vapor in the outdoor environment can easily condense into frost and adsorb on the fin heat exchanger when it flows through the fin heat exchanger. As the heat pump unit continues to work, the frost layer gradually thickens, resulting in a gradual weakening of the heat exchange capacity with the outdoor air. Therefore, the heat pump unit needs to be defrosted after running for a period of time. At present, most of them use hot fluorine defrosting, that is, heating and defrosting the fins through the reversing action of the four-way valve. The main sources of heat for heating the fin heat exchanger are: one is a small amount of electric heat from the compressor, and the other is a large amount of heat extracted from the user side water system, which causes the water temperature in the user side water system to drop significantly, affecting the heating on the user side of the system and even causing discomfort. Summary of the invention

[0004] To this end, the present invention provides a low ambient temperature air source heat pump system and method for constant temperature hot water supply, which is a constant temperature hot water supply air source heat pump system suitable for extremely cold areas, especially under low ambient temperature conditions. The system can achieve a continuous and stable hot water supply function in a low ambient temperature environment and meet the constant temperature hot water supply demand in cold climates.

[0005] In order to solve the above technical problems, in a first aspect, the present invention provides a low ambient temperature air source heat pump system for constant temperature hot water supply, comprising a compressor, a three-way valve 1, a gas-liquid separator, a use-side heat exchanger, a one-way valve 1, a one-way valve 2, a one-way valve 3, a one-way valve 4, a liquid reservoir, an economizer, a throttling element 1, a throttling element 2, a three-way valve 2, a three-way valve 3, a fan 1, a fin heat exchanger 1, a fan 2, a fin heat exchanger 2, a three-way valve 4, and a three-way valve 5;

[0006] Wherein, the first end of the compressor is respectively connected to the D interfaces of the three-way valve 1, the three-way valve 2 and the three-way valve 3;

[0007] The second end of the compressor is connected to the S interface of the three-way valve 1 and the S interfaces of the three-way valve 2 and the three-way valve 3 respectively through a gas-liquid separator;

[0008] The first end of the user-side heat exchanger is connected to the E interface of the three-way valve 1, and the second end of the user-side heat exchanger is connected to the first end of each of the one-way valve 3 and the one-way valve 4;

[0009] The first end and the second end of the fin heat exchanger 1 are respectively connected to the E interfaces of the three-way valve 2 and the three-way valve 4, and the first end and the second end of the fin heat exchanger 2 are respectively connected to the E interfaces of the three-way valve 5 and the three-way valve 3;

[0010] The third end and the fourth end of the fin heat exchanger 1 are connected, the third end and the fourth end of the fin heat exchanger 2 are connected, the third end of the fin heat exchanger 1 is connected to the fourth end of the fin heat exchanger 2, and the fourth end of the fin heat exchanger 1 is connected to the third end of the fin heat exchanger 2;

[0011] The one-way valve three is respectively connected to the fourth end of the fin heat exchanger one and the third end of the fin heat exchanger two;

[0012] The second end of the one-way valve 4 is respectively connected to the first end of the one-way valve 2 and the first end of the throttling element 2;

[0013] The second end of the one-way valve 2 is connected to the second end of the one-way valve 3 and to the S interfaces of the three-way valve 4 and the three-way valve 5 respectively through the one-way valve 1;

[0014] The second end of the throttling element 2 is connected to the first end and the second end of the economizer through the throttling element 1, the third end of the economizer is connected to the first end, and the fourth end is connected to the second end;

[0015] The third end of the economizer is connected to the third end of the compressor, and the fourth end of the economizer is respectively connected to the third end of the fin heat exchanger 1 and the fourth end of the fin heat exchanger 2 through the liquid reservoir, and is respectively connected to the D interface of the three-way valve 4 and the three-way valve 5;

[0016] The fan 1 is arranged on one side of the fin heat exchanger 1, and the fan 2 is arranged on one side of the fin heat exchanger 2.

[0017] In one embodiment of the present invention, the corresponding D interfaces and E interfaces of the three-way valve 1, the three-way valve 2, the three-way valve 3, the three-way valve 4 and the three-way valve 5 are connected when the power is on, and the corresponding S interfaces and E interfaces are connected when the power is off.

[0018] In one embodiment of the present invention, the throttling element 1 and the throttling element 2 are both electronic expansion valves.

[0019] In one embodiment of the present invention, the fan 1 and the fin heat exchanger 1 form an air path 1 through a surrounding sheet metal, and the fan 2 and the fin heat exchanger 2 form an air path 2 through a surrounding sheet metal, and the air path 1 and the air path 2 are independent of each other.

[0020] In a second aspect, the present invention provides a refrigeration method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, comprising:

[0021] S1, control the three-way valve 1, the three-way valve 4, and the three-way valve 5 to be powered off, control the three-way valve 2 and the three-way valve 3 to be powered on, control the throttling element 1 to be closed, and the fan 1, the fan 2, and the compressor to be started;

[0022] S2. The high-temperature and high-pressure refrigerant discharged from the compressor enters the D interfaces of the three-way valve 2 and the three-way valve 3 through the pipeline and is divided into two paths:

[0023] One refrigerant flows from the D interface of the three-way valve 2 into its E interface, and flows to the fin heat exchanger 1 through the pipeline. Under the action of the fan 1, the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger 1, and then flows into its S interface through the E interface of the three-way valve 4 through the pipeline;

[0024] Another refrigerant flows from the D interface of the three-way valve 3 into the E interface, and flows to the fin heat exchanger 2 through the pipeline. Under the action of the fan 2, the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger 2, and then flows into its S interface through the E interface of the three-way valve 5 through the pipeline;

[0025] S3, the two paths of normal temperature and high pressure refrigerants merge through the connecting pipeline and enter the one-way valve 1, and then are divided into two paths again, and are further supercooled in the fin heat exchanger 1 and the fin heat exchanger 2 respectively before merging;

[0026] S4, the merged refrigerant enters the liquid accumulator and then flows into the economizer. After the refrigerant flows out of the economizer, it is throttled and depressurized by the throttling element 2 and converted into low-temperature and low-pressure refrigerant wet vapor;

[0027] S5, the wet refrigerant vapor enters the user-side heat exchanger through the one-way valve 4, exchanges heat with the working medium, absorbs heat, and realizes refrigeration;

[0028] S6. The refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 1, flows into the gas-liquid separator through the pipeline, and then returns to the compressor to enter the next cycle.

[0029] In a third aspect, the present invention provides a heating method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, comprising:

[0030] S1, controlling the three-way valve 1 to be powered on, controlling the three-way valve 2, the three-way valve 3, the three-way valve 4 and the three-way valve 5 to be powered off, and controlling the fan 1, the fan 2 and the compressor to start;

[0031] S2, the high-temperature and high-pressure refrigerant discharged from the compressor flows into the E interface through the D interface of the three-way valve and then flows out to the user-side heat exchanger. In the user-side heat exchanger, the refrigerant releases heat to the working medium;

[0032] S3, after the refrigerant flows out of the user-side heat exchanger, it is divided into two paths through the one-way valve:

[0033] One path flows to the fin heat exchanger 1 for supercooling and heat release, and the other path flows to the fin heat exchanger 2 for supercooling and heat release;

[0034] S4, the two refrigerant paths merge into one path through the connecting pipe and enter the liquid accumulator, and the refrigerant flowing out of the liquid accumulator enters the economizer to further release heat, and then the refrigerant is divided into two paths again:

[0035] After being throttled and depressurized by the throttling element, the gas enters the economizer for evaporation and absorption of heat, and returns to the compressor through the air supply port;

[0036] The other path is throttled and depressurized by the throttling element 2, and then is divided into two paths again by the one-way valve 2:

[0037] The first refrigerant flows into the E interface through the S interface of the three-way valve four, enters the fin heat exchanger one, absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve one and then flows out;

[0038] The second refrigerant flows into the E interface through the S interface of the three-way valve five, enters the fin heat exchanger two, absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve three and then flows out;

[0039] S5. After the two refrigerants flowing out from the S interface of the three-way valve 1 and the S interface of the three-way valve 3 merge, they enter the compressor through the gas-liquid separator and enter the next cycle.

[0040] In a fourth aspect, the present invention provides a defrosting method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, comprising:

[0041] S1. When the fin heat exchanger 1 reaches the defrosting condition, the three-way valve 1 is controlled to remain powered on in the original state, the three-way valve 2 and the three-way valve 4 are controlled to be powered on, the three-way valve 3 and the three-way valve 5 are controlled to be powered off, the fan 1 is controlled to be stopped, and the fan 2 is controlled to be started;

[0042] S2. The high-temperature and high-pressure refrigerant discharged from the compressor is divided into two paths:

[0043] One path flows from the D interface of the three-way valve 1 to the E interface and then flows out to the user-side heat exchanger. In the user-side heat exchanger, the refrigerant releases heat to the working medium. After passing through the one-way valve 3, the refrigerant is divided into two paths again. The two paths respectively enter the supercooling pipelines of the fin heat exchanger 1 and the fin heat exchanger 2 to release heat and suppress ice, and then merge into the liquid storage tank;

[0044] The other path flows into the E interface through the D interface of the three-way valve 2 and then flows out, and then enters the fin heat exchanger 1, releases heat in the fin heat exchanger 1, and performs rapid defrosting. The defrosted refrigerant flows into the D interface through the E interface of the three-way valve 4 and then flows out, and then flows into the liquid storage tank through the connecting pipeline;

[0045] S3, the refrigerant flowing out of the liquid storage device enters the economizer, further releases heat and is subcooled before being divided into two paths:

[0046] After being throttled by the throttling element, it enters the economizer to evaporate and absorb heat, and then returns to the air supply port of the compressor;

[0047] The other path is throttled and depressurized through the throttling element 2, and after passing through the one-way valve 2, it flows into the E interface through the S interface of the three-way valve 5 and flows out, and enters the fin heat exchanger 2. Under the action of the fan 2, it continuously absorbs heat from the environment. The refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 3 and then flows out, and after passing through the gas-liquid separator, it flows back to the compressor and enters the next cycle.

[0048] In a fifth aspect, the present invention provides a defrosting method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, comprising:

[0049] S1. When the fin heat exchanger 2 reaches the defrosting condition, the three-way valve 1 is controlled to remain powered on in the original state, the three-way valve 2 and the three-way valve 5 are controlled to be powered on, the three-way valve 2 and the three-way valve 4 are controlled to be powered off, the fan 1 is controlled to be stopped, and the fan 2 is controlled to be started;

[0050] S2. The high-temperature and high-pressure refrigerant discharged from the compressor is divided into two paths:

[0051] One path flows out from the E interface of the three-way valve 1 and enters the user-side heat exchanger. After condensation and heat release, it is divided into two paths through the one-way valve and enters the subcooling pipelines of the fin heat exchanger 1 and the fin heat exchanger 2 respectively to further release heat and suppress ice, and then merges into the liquid storage tank;

[0052] The other path enters the fin heat exchanger 2 through the E interface of the three-way valve 3, releases heat in the fin heat exchanger 2, and performs rapid defrosting. After defrosting, the refrigerant flows into the D interface through the E interface of the three-way valve 5, and then returns to the liquid storage device;

[0053] S3, the refrigerant flowing out of the liquid accumulator enters the economizer to evaporate and absorb heat after being throttled by the economizer, and then returns to the air supply port of the compressor;

[0054] The other path is throttled and depressurized through the throttling element 2, and after passing through the one-way valve 2, it flows into the E interface through the S interface of the three-way valve 4 and then flows out, enters the fin heat exchanger 1, and then flows into the S interface through the E interface of the three-way valve 2 and then flows out, flows back to the compressor through the gas-liquid separator, and enters the next cycle.

[0055] The above technical solution of the present invention has the following advantages compared with the prior art:

[0056] The low ambient temperature air source heat pump system and method for constant temperature hot water supply described in the present invention can keep the compressor running during the heating period of the heat pump unit, and air path 1 and air path 2 absorb heat from the ambient side together. During defrosting, the two air paths defrost independently and alternately without affecting each other, ensuring continuous and stable heating of the system. It can operate efficiently in extremely cold climates and meet the demand for constant temperature hot water supply in severe cold areas. The present invention can not only be used for heat pump heating, but also take into account the refrigeration needs of some areas.

[0057] The system of the present invention adopts an independent air path design. During the defrosting process, the two air paths (fan and fin heat exchanger) operate alternately to ensure continuous heating during defrosting without affecting the constant temperature hot water supply on the user side. Through the coordination of three-way valve control and independent air paths, the fin heat exchanger quickly releases heat to defrost during the defrosting process, while other parts of the system continue to work stably, effectively improving the defrosting efficiency and reducing the system downtime. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0059] Figure 1 It is a structural schematic diagram of the low ambient temperature air source heat pump system for constant temperature hot water supply in Example 1 of the present invention.

[0060] Figure 2It is a working schematic diagram of the low ambient temperature air source heat pump system for constant temperature hot water supply in Example 2 of the present invention.

[0061] Figure 3 It is a working schematic diagram of the low ambient temperature air source heat pump system for constant temperature hot water supply in Example 3 of the present invention.

[0062] Figure 4 It is a working schematic diagram of the low ambient temperature air source heat pump system for constant temperature hot water supply in Example 4 of the present invention.

[0063] Figure 5 It is a working schematic diagram of the low ambient temperature air source heat pump system for constant temperature hot water supply in Example 5 of the present invention.

[0064] Description of the Figures in the Specification:

[0065] 1. Compressor; 2. Three-way valve 1; 3. Gas-liquid separator; 4. Heat exchanger on the user side; 5. One-way valve 1; 6. One-way valve 2; 7. One-way valve 3; 8. One-way valve 4; 9. Liquid storage tank; 10. Economizer; 11. Throttling element 1; 12. Throttling element 2; 13. Three-way valve 2; 14. Three-way valve 3; 15. Fan 1; 16. Fin heat exchanger 1; 17. Fan 2; 18. Fin heat exchanger 2; 19. Three-way valve 4; 20. Three-way valve 5. DETAILED DESCRIPTION

[0066] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0067] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0068] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0069] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0070] Example 1

[0071] Reference Figure 1 As shown, this embodiment provides a low ambient temperature air source heat pump system for constant temperature hot water supply, including a compressor 1, a three-way valve 1 2, a gas-liquid separator 3, a user-side heat exchanger 4, a one-way valve 1 5, a one-way valve 2 6, a one-way valve 3 7, a one-way valve 4 8, a liquid reservoir 9, an economizer 10, a throttling element 1 11, a throttling element 2 12, a three-way valve 2 13, a three-way valve 3 14, a fan 1 15, a fin heat exchanger 1 16, a fan 2 17, a fin heat exchanger 2 18, a three-way valve 4 19, and a three-way valve 5 20;

[0072] The first end of the compressor 1 is respectively connected to the D interfaces of the three-way valve 1 2 , the three-way valve 2 13 and the three-way valve 3 14 ;

[0073] The second end of the compressor 1 is connected to the S interface of the three-way valve 1 2 and the S interfaces of the three-way valve 2 13 and the three-way valve 3 14 respectively through the gas-liquid separator 3;

[0074] The first end of the user-side heat exchanger 4 is connected to the E interface of the three-way valve 1 2, and the second end of the user-side heat exchanger 4 is connected to the first end of each of the one-way valve 3 7 and the one-way valve 4 8;

[0075] The first end and the second end of the fin heat exchanger 16 are respectively connected to the E interfaces of the three-way valve 2 13 and the three-way valve 4 19, and the first end and the second end of the fin heat exchanger 2 18 are respectively connected to the E interfaces of the three-way valve 5 20 and the three-way valve 3 14;

[0076] The third end and the fourth end of the fin heat exchanger 1 16 are connected, the third end and the fourth end of the fin heat exchanger 2 18 are connected, the third end of the fin heat exchanger 1 16 is connected to the fourth end of the fin heat exchanger 2 18, and the fourth end of the fin heat exchanger 1 16 is connected to the third end of the fin heat exchanger 2 18;

[0077] The one-way valve three 7 is respectively connected to the fourth end of the fin heat exchanger one 16 and the third end of the fin heat exchanger two 18;

[0078] The second end of the one-way valve 4 8 is respectively connected to the first end of the one-way valve 2 6 and the throttling element 2 12;

[0079] The second end of the one-way valve 2 6 is connected to the second end of the one-way valve 3 7 and to the S interface of the three-way valve 4 19 and the three-way valve 5 20 respectively through the one-way valve 1 5;

[0080] The second end of the throttling element 2 12 is connected to the first end and the second end of the economizer 10 through the throttling element 1 11, and the third end of the economizer 10 is connected to the first end, and the fourth end is connected to the second end;

[0081] The third end of the economizer 10 is connected to the third end of the compressor 1, and the fourth end of the economizer 10 is connected to the third end of the fin heat exchanger 1 16 and the fourth end of the fin heat exchanger 2 18 through the liquid reservoir 9, and is connected to the D interfaces of the three-way valve 4 19 and the three-way valve 5 20, respectively;

[0082] The fan 15 is disposed on one side of the fin heat exchanger 1 16 , and the fan 2 17 is disposed on one side of the fin heat exchanger 2 18 .

[0083] Specifically, the three-way valve 1 2, the three-way valve 2 13, the three-way valve 3 14, the three-way valve 4 19 and the three-way valve 5 20 have their corresponding D interfaces and E interfaces connected when power is on, and have their corresponding S interfaces and E interfaces connected when power is off.

[0084] Specifically, the throttling element 1 1 and the throttling element 2 12 are both electronic expansion valves.

[0085] Specifically, the fan 15 and the fin heat exchanger 1 16 form an air path 1 through a surrounding sheet metal, and the fan 2 17 and the fin heat exchanger 2 18 form an air path 2 through a surrounding sheet metal, and the air path 1 and the air path 2 are independent of each other.

[0086] Example 2

[0087] Reference Figure 2 As shown, this embodiment provides a refrigeration method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, including:

[0088] S1, control the three-way valve 1 2, the three-way valve 4 19, and the three-way valve 5 20 to be powered off, control the three-way valve 2 13 and the three-way valve 3 14 to be powered on, control the throttling element 1 11 to be closed, and control the fan 1 15, the fan 2 17, and the compressor 1 to be started;

[0089] S2. The high-temperature and high-pressure refrigerant discharged from the compressor 1 enters the D interfaces of the three-way valve 2 13 and the three-way valve 3 14 through the pipeline and is divided into two paths:

[0090] One refrigerant flows from the D interface of the three-way valve 13 to its E interface, and flows to the fin heat exchanger 16 through the pipeline. Under the action of the fan 15, the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger 16, and then flows into its S interface through the E interface of the three-way valve 19 through the pipeline;

[0091] Another refrigerant flows from the D interface of the three-way valve 14 to the E interface, and flows to the fin heat exchanger 18 through the pipeline. Under the action of the fan 17, the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger 18, and then flows into the S interface of the three-way valve 5 20 through the pipeline via the E interface.

[0092] S3, the two normal temperature high pressure refrigerants merge through the connecting pipeline and enter the one-way valve 1 5, and then are divided into two paths again, and are further supercooled in the fin heat exchanger 1 16 and the fin heat exchanger 2 18 and then merged;

[0093] S4, the combined refrigerant enters the liquid storage tank 9, and then flows into the economizer 10. After the refrigerant flows out of the economizer 10, it is throttled and depressurized by the throttling element 2 12, and is converted into low-temperature and low-pressure refrigerant wet vapor;

[0094] S5, the wet refrigerant vapor enters the user-side heat exchanger 4 through the one-way valve 48, exchanges heat with the working medium, absorbs heat, and realizes refrigeration;

[0095] S6, the refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 2, flows into the gas-liquid separator 3 through the pipeline, and then returns to the compressor 1 to enter the next cycle, thereby achieving refrigeration.

[0096] Example 3

[0097] Reference Figure 3 As shown, this embodiment provides a heating method, using the low ambient temperature air source heat pump system for constant temperature hot water supply, including:

[0098] S1, control the three-way valve 1 2 to be powered on, control the three-way valve 2 13, the three-way valve 3 14, the three-way valve 4 19 and the three-way valve 5 20 to be powered off, and control the fan 1 15, the fan 2 17 and the compressor 1 to start;

[0099] S2, the high-temperature and high-pressure refrigerant discharged from the compressor 1 flows into the E interface through the D interface of the three-way valve and then flows out to the user-side heat exchanger 4. In the user-side heat exchanger 4, the refrigerant releases heat to the working medium;

[0100] S3, after the refrigerant flows out of the user-side heat exchanger 4, it is divided into two paths through the one-way valve 3 7:

[0101] One path flows to the fin heat exchanger 16 for supercooling and heat release, and the other path flows to the fin heat exchanger 2 18 for supercooling and heat release;

[0102] S4, the two refrigerant paths merge into one path through the connecting pipeline and enter the liquid accumulator 9. The refrigerant flowing out of the liquid accumulator 9 enters the economizer 10 to further release heat. Subsequently, the refrigerant is divided into two paths again:

[0103] After being throttled and depressurized by the throttling element 11, the gas enters the economizer 10 for evaporation and absorption of heat, and returns to the compressor 1 through the air supply port;

[0104] The other path is throttled and depressurized by the throttling element 12, and then is divided into two paths again by the one-way valve 6:

[0105] The first refrigerant flows into the E interface through the S interface of the three-way valve four 19, enters the fin heat exchanger one 16, absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve one 2 and then flows out;

[0106] The second refrigerant flows into the E interface through the S interface of the three-way valve five 20, enters the fin heat exchanger two 18, absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve three 14 and then flows out;

[0107] S5, after the two refrigerants flowing out of the S interface of the three-way valve 1 2 and the S interface of the three-way valve 3 14 merge, they enter the compressor 1 through the gas-liquid separator 3 and enter the next cycle, thereby achieving heating.

[0108] Example 4

[0109] Reference Figure 4 As shown, this embodiment provides a defrosting method (air path one), using the low ambient temperature air source heat pump system for constant temperature hot water supply, including:

[0110] S1. When the fin heat exchanger 16 reaches the defrosting condition, the three-way valve 12 is controlled to remain powered on in the original state, the three-way valve 2 13 and the three-way valve 4 19 are controlled to be powered on, the three-way valve 3 14 and the three-way valve 5 20 are controlled to be powered off, the fan 15 is controlled to be stopped, and the fan 2 17 is controlled to be started;

[0111] S2. The high-temperature and high-pressure refrigerant discharged from the compressor 1 is divided into two paths:

[0112] One path flows from the D interface of the three-way valve 1 2 to the E interface and then flows out to the user-side heat exchanger 4. In the user-side heat exchanger 4, the refrigerant releases heat to the working medium. After passing through the one-way valve 3 7, the refrigerant is divided into two paths again. The two paths respectively enter the supercooling pipelines of the fin heat exchanger 1 16 and the fin heat exchanger 2 18 to release heat and suppress ice, and then merge into the liquid storage tank 9;

[0113] The other path flows into the E interface through the D interface of the three-way valve 2 13 and then flows out, and then enters the fin heat exchanger 16, where heat is released for rapid defrosting. The defrosted refrigerant flows into the D interface through the E interface of the three-way valve 4 19 and then flows out, and then enters the liquid storage tank 9 through the connecting pipeline;

[0114] S3, the refrigerant flowing out of the liquid storage tank 9 enters the economizer 10, and is further divided into two paths after heat release and supercooling:

[0115] After being throttled by the throttling element 11, it enters the economizer 10 to evaporate and absorb heat, and then returns to the air supply port of the compressor 1;

[0116] The other path is throttled and depressurized through the throttling element 2 12, and after passing through the one-way valve 2 6, it flows into the E interface through the S interface of the three-way valve 5 20 and flows out, and enters the fin heat exchanger 2 18. Under the action of the fan 2 17, it continuously absorbs heat from the environment. The refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 3 14 and then flows out, and after passing through the gas-liquid separator 3, it flows back to the compressor 1 and enters the next cycle.

[0117] It should be noted that during the defrosting process, the compressor 1 continues to work, the fin heat exchanger 2 18 continues to draw heat from the outdoor environment, and the fin heat exchanger 1 16 performs rapid defrosting, thereby achieving the design goal of continuously providing stable domestic hot water.

[0118] Example 5

[0119] Reference Figure 5 As shown, this embodiment provides a defrosting method (air path 2), using the low ambient temperature air source heat pump system for constant temperature hot water supply, including:

[0120] S1. When the fin heat exchanger 2 18 reaches the defrosting condition, the three-way valve 1 2 is controlled to remain powered on in the original state, the three-way valve 2 13 and the three-way valve 5 20 are controlled to be powered on, the three-way valve 2 13 and the three-way valve 4 19 are controlled to be powered off, the fan 1 15 is controlled to be stopped, and the fan 2 17 is controlled to be started;

[0121] S2. The high-temperature and high-pressure refrigerant discharged from the compressor 1 is divided into two paths:

[0122] One path flows out from the E interface of the three-way valve 1 2 and enters the user-side heat exchanger 4. After condensation and heat release, it is divided into two paths through the one-way valve 3 7 and enters the subcooling pipelines of the fin heat exchanger 1 16 and the fin heat exchanger 2 18 respectively to further release heat and suppress ice, and then merges into the liquid storage tank 9;

[0123] The other path enters the fin heat exchanger 2 18 through the E interface of the three-way valve 3 14, releases heat in the fin heat exchanger 2 18, and performs rapid defrosting. After defrosting, the refrigerant flows into the D interface through the E interface of the three-way valve 5 20, and then returns to the liquid storage tank 9;

[0124] S3, the refrigerant flowing out of the liquid storage tank 9 enters the economizer 10 after throttling to evaporate and absorb heat, and then returns to the air supply port of the compressor 1;

[0125] The other path is throttled and depressurized through the throttling element 2 12, and after passing through the one-way valve 2 6, it flows into the E interface through the S interface of the three-way valve 4 19 and then flows out, enters the fin heat exchanger 16, and then flows into the S interface through the E interface of the three-way valve 2 13 and then flows out, flows back to the compressor 1 through the gas-liquid separator 3, and enters the next cycle.

[0126] It should be noted that during the defrosting process, the compressor 1 continues to work, the fin heat exchanger 16 continues to absorb heat from the outdoor environment, and the fin heat exchanger 16 performs rapid defrosting to achieve the design goal of continuously providing stable domestic hot water.

[0127] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A low ambient temperature air source heat pump system for constant temperature hot water supply, characterized in that: It comprises a compressor (1), a three-way valve 1 (2), a gas-liquid separator (3), a user-side heat exchanger (4), a one-way valve 1 (5), a one-way valve 2 (6), a one-way valve 3 (7), a one-way valve 4 (8), a liquid storage device (9), an economizer (10), a throttling element 1 (11), a throttling element 2 (12), a three-way valve 2 (13), a three-way valve 3 (14), a fan 1 (15), a fin heat exchanger 1 (16), a fan 2 (17), a fin heat exchanger 2 (18), a three-way valve 4 (19), and a three-way valve 5 (20); Wherein, the first end of the compressor (1) is respectively connected to the D interfaces of the three-way valve 1 (2), the three-way valve 2 (13) and the three-way valve 3 (14); The second end of the compressor (1) is connected to the S interface of the three-way valve 1 (2) and the S interfaces of the three-way valve 2 (13) and the three-way valve 3 (14) respectively through a gas-liquid separator (3); The first end of the user-side heat exchanger (4) is connected to the E interface of the three-way valve 1 (2), and the second end of the user-side heat exchanger (4) is connected to the first end of each of the one-way valve 3 (7) and the one-way valve 4 (8); The first end and the second end of the fin heat exchanger one (16) are respectively connected to the E interfaces of the three-way valve two (13) and the three-way valve four (19), and the first end and the second end of the fin heat exchanger two (18) are respectively connected to the E interfaces of the three-way valve five (20) and the three-way valve three (14); The third end and the fourth end of the fin heat exchanger 1 (16) are connected, the third end and the fourth end of the fin heat exchanger 2 (18) are connected, the third end of the fin heat exchanger 1 (16) is connected to the fourth end of the fin heat exchanger 2 (18), and the fourth end of the fin heat exchanger 1 (16) is connected to the third end of the fin heat exchanger 2 (18); The one-way valve three (7) is respectively connected to the fourth end of the fin heat exchanger one (16) and the third end of the fin heat exchanger two (18); The second end of the one-way valve four (8) is respectively connected to the first end of the one-way valve two (6) and the throttling element two (12); The second end of the one-way valve 2 (6) is connected to the second end of the one-way valve 3 (7) through the one-way valve 1 (5) and is connected to the S interfaces of the three-way valve 4 (19) and the three-way valve 5 (20); The second end of the throttling element 2 (12) is connected to the first end and the second end of the economizer (10) through the throttling element 1 (11); the third end of the economizer (10) is connected to the first end, and the fourth end is connected to the second end; The third end of the economizer (10) is connected to the third end of the compressor (1), and the fourth end of the economizer (10) is respectively connected to the third end of the fin heat exchanger 1 (16) and the fourth end of the fin heat exchanger 2 (18) through the liquid reservoir (9), and is respectively connected to the D interfaces of the three-way valve 4 (19) and the three-way valve 5 (20); The fan one (15) is arranged on one side of the fin heat exchanger one (16), and the fan two (17) is arranged on one side of the fin heat exchanger two (18).

2. A low ambient temperature air source heat pump system for constant temperature hot water supply according to claim 1, characterized in that: When the three-way valve 1 (2), the three-way valve 2 (13), the three-way valve 3 (14), the three-way valve 4 (19) and the three-way valve 5 (20) are powered on, the corresponding D interfaces and E interfaces are connected, and when the power is off, the corresponding S interfaces and E interfaces are connected.

3. A low ambient temperature air source heat pump system for constant temperature hot water supply according to claim 1, characterized in that: The throttling element 1 (11) and the throttling element 2 (12) are both electronic expansion valves.

4. A low ambient temperature air source heat pump system for constant temperature hot water supply according to claim 1, characterized in that: The fan 1 (15) and the fin heat exchanger 1 (16) form a first air path through a surrounding sheet metal, and the fan 2 (17) and the fin heat exchanger 2 (18) form a second air path through a surrounding sheet metal. The first air path and the second air path are independent of each other.

5. A refrigeration method, characterized in that: A low ambient temperature air source heat pump system for constant temperature hot water supply using any one of claims 1 to 4, comprising: S1, control the three-way valve 1 (2), the three-way valve 4 (19), and the three-way valve 5 (20) to be powered off, control the three-way valve 2 (13) and the three-way valve 3 (14) to be powered on, control the throttling element 1 (11) to be closed, and control the fan 1 (15), the fan 2 (17), and the compressor (1) to be started; S2. The high-temperature and high-pressure refrigerant discharged from the compressor (1) enters the D interfaces of the three-way valve 2 (13) and the three-way valve 3 (14) through the pipeline and is divided into two paths: A refrigerant flows from the D interface of the three-way valve 2 (13) into its E interface, and flows to the fin heat exchanger 1 (16) through the pipeline. Under the action of the fan 1 (15), the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger 1 (16), and then flows into its S interface through the E interface of the three-way valve 4 (19) through the pipeline; Another refrigerant flows from the D interface of the three-way valve (14) into the E interface, and flows to the fin heat exchanger (18) through the pipeline. Under the action of the fan (17), the high-temperature and high-pressure refrigerant is condensed into normal-temperature and high-pressure refrigerant in the fin heat exchanger (18), and then flows into the S interface of the three-way valve (20) through the pipeline via the E interface. S3, the two paths of normal temperature and high pressure refrigerants merge through the connecting pipeline and enter the one-way valve 1 (5), and then are divided into two paths again, and are further subcooled in the fin heat exchanger 1 (16) and the fin heat exchanger 2 (18) respectively before merging; S4, the combined refrigerant enters the liquid storage tank (9), and then flows into the economizer (10). After the refrigerant flows out of the economizer (10), it is throttled and depressurized by the throttling element 2 (12), and is converted into low-temperature and low-pressure refrigerant wet vapor; S5, the wet refrigerant vapor enters the user-side heat exchanger (4) through the one-way valve four (8), exchanges heat with the working medium, absorbs heat, and realizes refrigeration; S6. The refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 1 (2), flows into the gas-liquid separator (3) through the pipeline, and then returns to the compressor (1) to enter the next cycle.

6. A heating method, characterized in that: A low ambient temperature air source heat pump system for constant temperature hot water supply using any one of claims 1 to 4, comprising: S1, controlling the three-way valve 1 (2) to be powered on, controlling the three-way valve 2 (13), the three-way valve 3 (14), the three-way valve 4 (19) and the three-way valve 5 (20) to be powered off, and controlling the fan 1 (15), the fan 2 (17) and the compressor (1) to start; S2, the high-temperature and high-pressure refrigerant discharged from the compressor (1) flows into the E interface through the D interface of the three-way valve and then flows out to enter the user-side heat exchanger (4), and in the user-side heat exchanger (4), the refrigerant releases heat to the working medium; S3. After the refrigerant flows out of the user-side heat exchanger (4), it is divided into two paths through the one-way valve three (7): One path flows to the fin heat exchanger 1 (16) for supercooling and heat release, and the other path flows to the fin heat exchanger 2 (18) for supercooling and heat release; S4. The two refrigerant paths merge into one path through the connecting pipeline and enter the liquid storage device (9). The refrigerant flowing out of the liquid storage device (9) enters the economizer (10) to further release heat. Subsequently, the refrigerant is divided into two paths again: After being throttled and depressurized by the throttling element 1 (11), the gas enters the economizer (10) to evaporate and absorb heat, and then returns to the compressor (1) through the air supply port; The other path is throttled and depressurized by the throttling element 2 (12) and then divided into two paths again by the one-way valve 2 (6): The first refrigerant flows into the E interface through the S interface of the three-way valve four (19), enters the fin heat exchanger one (16), absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve one (2) and then flows out; The second refrigerant flows into the E interface through the S interface of the three-way valve five (20), enters the fin heat exchanger two (18), absorbs heat from the air, and then flows into the S interface through the E interface of the three-way valve three (14) and then flows out; S5, after the two refrigerants flowing out from the S interface of the three-way valve one (2) and the S interface of the three-way valve three (14) merge, they enter the compressor (1) through the gas-liquid separator (3) and enter the next cycle.

7. A defrosting method, characterized in that: A low ambient temperature air source heat pump system for constant temperature hot water supply using any one of claims 1 to 4, comprising: S1. When the fin heat exchanger 1 (16) reaches the defrosting condition, the three-way valve 1 (2) is controlled to remain powered on in the original state, the three-way valve 2 (13) and the three-way valve 4 (19) are controlled to be powered on, the three-way valve 3 (14) and the three-way valve 5 (20) are controlled to be powered off, the fan 1 (15) is controlled to be stopped, and the fan 2 (17) is controlled to be started; S2. The high-temperature and high-pressure refrigerant discharged from the compressor (1) is divided into two paths: One path flows from the D interface of the three-way valve 1 (2) to the E interface and then flows out to the user-side heat exchanger (4). In the user-side heat exchanger (4), the refrigerant releases heat to the working medium. After passing through the one-way valve 3 (7), the refrigerant is divided into two paths again. The two paths respectively enter the subcooling pipelines of the fin heat exchanger 1 (16) and the fin heat exchanger 2 (18) to release heat and suppress ice, and then merge into the liquid storage tank (9); The other path flows into the E interface through the D interface of the three-way valve two (13) and then flows out, and then enters the fin heat exchanger one (16), where heat is released to perform rapid defrosting. The defrosted refrigerant flows into the D interface through the E interface of the three-way valve four (19) and then flows out, and then flows into the liquid storage tank (9) through the connecting pipeline; S3. The refrigerant flowing out of the liquid storage device (9) enters the economizer (10), and after further heat release and supercooling, is divided into two paths: After being throttled by the throttling element 1 (11), the gas enters the economizer (10) to evaporate and absorb heat, and then returns to the air supply port of the compressor (1); The other path is throttled and depressurized through the throttling element 2 (12), and after passing through the one-way valve 2 (6), it flows into the E interface through the S interface of the three-way valve 5 (20) and flows out, and enters the fin heat exchanger 2 (18). Under the action of the fan 2 (17), it continuously absorbs heat from the environment. The refrigerant after absorbing heat flows into the S interface through the E interface of the three-way valve 3 (14) and then flows out, and after passing through the gas-liquid separator (3), it flows back to the compressor (1) and enters the next cycle.

8. A defrosting method, characterized in that: A low ambient temperature air source heat pump system for constant temperature hot water supply using any one of claims 1 to 4, comprising: S1. When the fin heat exchanger 2 (18) reaches the defrosting condition, the three-way valve 1 (2) is controlled to remain powered on in the original state, the three-way valve 2 (13) and the three-way valve 5 (20) are controlled to be powered on, the three-way valve 2 (13) and the three-way valve 4 (19) are controlled to be powered off, the fan 1 (15) is controlled to be stopped, and the fan 2 (17) is controlled to be started; S2. The high-temperature and high-pressure refrigerant discharged from the compressor (1) is divided into two paths: One path flows out from the E interface of the three-way valve one (2) and enters the user-side heat exchanger (4), and after condensation and heat release, it is divided into two paths through the one-way valve three (7) and enters the subcooling pipelines of the fin heat exchanger one (16) and the fin heat exchanger two (18) respectively to further release heat and suppress ice, and then merges and enters the liquid storage tank (9); The other path enters the fin heat exchanger 2 (18) through the E interface of the three-way valve 3 (14), releases heat in the fin heat exchanger 2 (18), and performs rapid defrosting. After defrosting, the refrigerant flows into the D interface through the E interface of the three-way valve 5 (20), and then returns to the liquid storage tank (9); S3, the refrigerant flowing out of the liquid storage device (9) enters the economizer (10) after being throttled by the economizer (10) to evaporate and absorb heat, and then returns to the air supply port of the compressor (1); The other path is throttled and depressurized through the throttling element 2 (12), and after passing through the one-way valve 2 (6), it flows into the E interface through the S interface of the three-way valve 4 (19), and then flows out, enters the fin heat exchanger 1 (16), and then flows into the S interface through the E interface of the three-way valve 2 (13), and then flows out, passes through the gas-liquid separator (3) and flows back to the compressor (1), entering the next cycle.

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