Heat pump system

Abstract

The utility model discloses a heat pump system which comprises at least two heat pump units, a primary water return pipe, a primary water supply pipe, a primary circulating pump, an energy storage water tank, first control valves respectively matched with the heat pump units, a circulating pipe and second control valves respectively matched with the heat pump units, the hot water outlet end of the heat pump unit is connected with the inlet end of the energy storage water tank sequentially through the inlet end of the first control valve, the outlet end of the first control valve and the primary water supply pipe. The hot water inlet end of the heat pump unit is connected with the outlet end of the energy storage water tank sequentially through a branch water return pipe and a primary water return pipe. The outlet end of the primary circulating pump is connected with the hot water inlet end of the heat pump unit through a primary water return pipe and a branch water return pipe in sequence; the inlet end of the primary circulating pump is connected with the outlet end of the energy storage water tank through a primary water return pipe; the device has the characteristics that the energy loss caused by water mixing can be avoided and reduced, and an operator can more accurately control the water supply temperature of hot water.

Description

Technical Field

[0001] The utility model relates to a heat pump system and belongs to the technical field of refrigeration. Background Art

[0002] Due to the needs of environmental protection and energy conservation, at present, heat pumps, especially air source heat pumps, have been widely applied as heat sources of heating systems in industrial, agricultural and civil fields. However, due to technical limitations, the heating capacity of a single air source heat pump is limited. Therefore, when used as the heat source of a heating system, multiple air source heat pumps generally operate in parallel. For example, Figure 4 FIG. shows a schematic diagram of a typical distributed air source heat pump central heating system. Usually, in such a distributed air source heat pump central heating system, at least two air source heat pumps are connected in parallel between a primary supply pipe 3 and a primary return pipe 2, and Figure 4 the system shown in FIG. has three air source heat pumps connected in parallel between the primary supply pipe 3 and the primary return pipe 2.

[0003] As is well known, in winter, with the increase or decrease of the outdoor air temperature, the output heating capacity of the heating system also needs to be adjusted. In order to respond to such changes in the output heating capacity of the heating system, the number of operating air source heat pumps in a distributed air source heat pump central heating system also needs to be increased or decreased.

[0004] For example: for Figure 4 the distributed heating system shown in FIG., when the outdoor air temperature rises in winter and the distributed heating system operates at part load, only two air source heat pumps in the system operate normally and the other one stops operating. However, due to the relatively low outdoor temperature in winter, in order to prevent the hot water from freezing due to heat dissipation to the surrounding environment and a decrease in water temperature after the hot water stops flowing in the stopped air source heat pump, which may cause damage to the stopped air source heat pump. Therefore, currently, the common anti-freezing measure for the stopped air source heat pump is that although the compressor, fan, etc. of the stopped air source heat pump stop operating, the hot water in the primary return pipe 2 still needs to continuously pass through the hot water heater of the stopped air source heat pump. The above anti-freezing measure, although it avoids damage to the stopped air source heat pump, also brings the following problems:

[0005] Such as Figure 4As shown in the figure, during operation, the hot water in the primary return pipe 2 is divided into three paths; two paths respectively pass through the hot water of two normally operating air source heat pumps 1. After being heated by the heat pump, the water temperature rises. Therefore, the hot water entering the primary supply pipe 3 has a relatively high temperature; while the hot water entering the primary supply pipe 3 through the stopped air source heat pump 1 has a relatively low temperature, which is still the return water temperature; so there is a mixing water loss during the mixing of these two parts of hot water in the primary supply pipe 3 and flowing into the energy storage water tank 5, resulting in an increase in the operating energy consumption of the distributed air source heat pump central heating system; in addition, it also makes it difficult for the operating personnel to accurately control the temperature of the hot water entering the energy storage water tank 5.

[0006] The above problems also exist during the defrosting process of the air source heat pump 1; still taking Figure 4 the distributed heating system shown in the figure as an example, when the outdoor air temperature is relatively low in winter, Figure 4 during the simultaneous operation of the three air source heat pumps 1 in the distributed heating system shown in the figure, when one of the air source heat pumps 1 meets the defrosting condition and enters the defrosting working condition and uses reverse cycle hot gas defrosting, the air source heat pump 1 entering the defrosting working condition not only cannot output heat to heat the return water entering the unit from the primary return pipe 2, but also needs to absorb heat from the return water for defrosting. After the return water is absorbed by heat, the water temperature further decreases and then enters the primary supply pipe 3, where it is mixed with the relatively high-temperature hot water coming out of the other two normally operating air source heat pumps 1 and then sent to the energy storage water tank 5. There is also a mixing water loss during the above mixing process, and it also makes it difficult for the operating personnel to accurately control the temperature of the hot water entering the energy storage water tank 5. Summary of the Invention

[0007] The purpose of the present utility model is to provide a heat pump system that can avoid and reduce the energy loss caused by water mixing and enable the operating personnel to more accurately control the hot water supply temperature.

[0008] In order to overcome the problems existing in the above technology, the technical solution for the present utility model to solve the technical problems is:

[0009] 1. A heat pump system, including at least two heat pump units (1), a primary return pipe (2), a primary supply pipe (3), a primary circulation pump (4), an energy storage water tank (5), and a first control valve (7) respectively matched with each heat pump unit (1), characterized in that: the heat pump system further includes a circulation pipe (12) and a second control valve (13) respectively matched with each heat pump unit (1);

[0010] The hot water outlet end of the heat pump unit (1) is successively connected to the inlet end of the energy storage water tank (5) through the inlet end of the first control valve (7), the outlet end of the first control valve (7), and the primary supply pipe (3);

[0011] The hot water inlet end of the heat pump unit (1) is successively connected to the outlet end of the energy storage water tank (5) through the branch return water pipe (6) and the primary return water pipe (2).

[0012] The primary circulation pump (4) is arranged on the primary return water pipe (2); that is: the outlet end of the primary circulation pump (4) is successively connected to the hot water inlet end of the heat pump unit (1) through the primary return water pipe (2) and the branch return water pipe (6); the inlet end of the primary circulation pump (4) is connected to the outlet end of the energy storage water tank (5) through the primary return water pipe (2).

[0013] The inlet end of the second control valve (13) is connected to the pipeline between the inlet end of the first control valve (7) and the hot water outlet end of the heat pump unit (1), and the outlet end of the second control valve (13) is connected to the primary return water pipe (2) between the inlet end of the primary circulation pump (4) and the outlet end of the energy storage water tank (5) through the circulation pipe (12).

[0014] 2. A heat pump system, comprising at least two heat pump units (1), a primary return water pipe (2), a primary water supply pipe (3), a primary circulation pump (4), and an energy storage water tank (5), characterized in that: the heat pump system further comprises a circulation pipe (12) and a shunt three-way regulating valve (14) respectively matched with each heat pump unit (1);

[0015] The hot water outlet end of the heat pump unit (1) is successively connected to the inlet end of the energy storage water tank (5) through the inlet end of the shunt three-way regulating valve (14), the direct current outlet end (15) of the shunt three-way regulating valve (14), and the primary water supply pipe (3).

[0016] The hot water inlet end of the heat pump unit (1) is successively connected to the outlet end of the energy storage water tank (5) through the branch return water pipe (6) and the primary return water pipe (2).

[0017] The primary circulation pump (4) is arranged on the primary return water pipe (2); that is: the outlet end of the primary circulation pump (4) is successively connected to the hot water inlet end of the heat pump unit (1) through the primary return water pipe (2) and the branch return water pipe (6); the inlet end of the primary circulation pump (4) is connected to the outlet end of the energy storage water tank (5) through the primary return water pipe (2).

[0018] The bypass outlet end (16) of the shunt three-way regulating valve (14) is connected to the primary return water pipe (2) between the inlet end of the primary circulation pump (4) and the outlet end of the energy storage water tank (5) through the circulation pipe (12).

[0019] 3. A heat pump system, comprising at least two heat pump units (1), a primary return pipe (2), a primary supply pipe (3), a primary circulation pump (4), and a heat storage water tank (5), characterized in that: the heat pump system further comprises a circulation pipe (12) and a flow dividing three-way regulating valve (14) respectively matched with each heat pump unit (1);

[0020] The hot water outlet end of the heat pump unit (1) is successively connected to the inlet end of the heat storage water tank (5) through the inlet end of the flow dividing three-way regulating valve (14), the bypass outlet end (16) of the flow dividing three-way regulating valve (14), and the primary supply pipe (3);

[0021] The hot water inlet end of the heat pump unit (1) is successively connected to the outlet end of the heat storage water tank (5) through the branch return pipe (6) and the primary return pipe (2);

[0022] The primary circulation pump (4) is arranged on the primary return pipe (2); that is: the outlet end of the primary circulation pump (4) is successively connected to the hot water inlet end of the heat pump unit (1) through the primary return pipe (2) and the branch return pipe (6); the inlet end of the primary circulation pump (4) is connected to the outlet end of the heat storage water tank (5) through the primary return pipe (2);

[0023] The direct current outlet end (15) of the flow dividing three-way regulating valve (14) is connected to the primary return pipe (2) between the inlet end of the primary circulation pump (4) and the outlet end of the heat storage water tank (5) through the circulation pipe (12).

[0024] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0025] 1. It can avoid and reduce the energy loss caused by water mixing;

[0026] 2. It can enable the operator to more precisely control the supply water temperature of the hot water;

[0027] 3. For cold and severe cold regions, it can improve the operation energy efficiency and the stability of the supply water temperature of the distributed heating system with a heat pump as the heat source, as well as the adjustability of the supply water temperature with the change of the outdoor air temperature;

[0028] 4. The present utility model is applicable to industrial and civil hot water heating systems with a heat pump as the heat source, and is particularly applicable to distributed central heating systems with an air source heat pump as the heat source. Description of the Drawings

[0029] Figure 1 It is a schematic structural diagram of Embodiment 1 of the present utility model;

[0030] Figure 2 It is a schematic structural diagram of Embodiment 2 of the present utility model;

[0031] Figure 3 It is a schematic structural diagram of Embodiment 3 of the present utility model;

[0032] Figure 4 It is a schematic structural diagram of the prior art. Specific embodiments

[0033] The following further details the content of the present utility model with reference to the accompanying drawings.

[0034] Embodiment 1

[0035] As Figure 1 shown, this embodiment is a heat pump system that can avoid and reduce energy losses caused by water mixing; and can enable operators to more precisely control the hot water supply temperature, and is used for winter central heating; the heat pump system uses outdoor air as the low-temperature heat source; the entire system includes the following components: heat pump unit 1, primary return pipe 2, primary supply pipe 3, primary circulation pump 4, first control valve 7, second control valve 13, energy storage water tank 5, secondary circulation pump 8, secondary supply pipe 10, secondary return pipe 11, circulation pipe 12, and user terminal 9.

[0036] Among them, the heat pump unit 1, primary return pipe 2, primary supply pipe 3, primary circulation pump 4, first control valve 7, second control valve 13, energy storage water tank 5, and circulation pipe 12 form a primary pump system. And the energy storage water tank 5, secondary circulation pump 8, secondary supply pipe 10, secondary return pipe 11, and user terminal 9 form a secondary pump system. During operation, the heat pump unit 1 uses reverse cycle hot gas defrosting.

[0037] The first control valve 7 and the second control valve 13 are solenoid valves and have the functions of fully open and fully closed.

[0038] Figure 1 The heat pump system shown has the following operating functions during winter operation: full load operation, partial load operation, and intermittent operation.

[0039] Under the full load operation function, there are also the following two operating conditions: the full load condition of normal operation and the full load condition of defrosting operation. Under the partial load operation function, there are also the following two operating conditions: the partial load condition of normal operation and the partial load condition of defrosting operation.

[0040] The working processes under each function are described as follows.

[0041] (1) Full load operation function

[0042] 1) Full load condition of normal operation

[0043] During the operation of this working condition, the heat pump unit 1 is an air source heat pump, and all are operating normally, extracting heat from the outdoor air and heating the system return water from the primary return pipe 2; the first control valve 7 is fully open, and the second control valve 13 is closed; the primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, using the hot water produced by the heat pump unit 1 to heat the users.

[0044] The working process of the hot water under this working condition is as described below:

[0045] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; each path of the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the heat pump unit 1, enters the heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the heat pump unit 1, the inlet end of the first control valve 7, and the outlet end of the first control valve 7, and enters the primary supply pipe 3 respectively; after the three paths of supply water are mixed in the primary supply pipe 3, they then sequentially pass through the primary supply pipe 3 and the inlet end of the energy storage tank 5, and enter the energy storage tank 5; the hot water in the energy storage tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the return water; then it returns to the primary return pipe 2 through the secondary return pipe 11; and then passes through the inlet end of the primary circulation pump 4 and enters the primary circulation pump 4 to increase the pressure, thus completing a full load working condition of a normal operation.

[0046] 2) Full load working condition of defrosting operation

[0047] During the operation of this working condition, the heat pump unit 1 is also an air source heat pump, and all three heat pump units 1 are operating simultaneously; however, two heat pump units 1 are operating normally, extracting heat from the outdoor air and heating the system return water from the primary return pipe 2; the first control valves 7 respectively matched with these two heat pump units 1 are fully open, and the second control valve 13 is closed; the remaining one heat pump unit 1 enters the defrosting working condition, and the first control valve 7 matched with this defrosting heat pump unit 1 is closed, and the second control valve 13 is fully open.

[0048] The primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, using the hot water produced by the two normally operating heat pump units 1 and the hot water stored in the energy storage tank 5 to heat the users.

[0049] The working process of the hot water under this working condition is as described below:

[0050] During operation, after the return water is pumped out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; two of the return water paths respectively enter the two heat pump units 1 that are operating normally. At this time, the return water sequentially passes through the branch return water pipe 6 and the hot water inlet end of the normally operating heat pump unit 1, enters the normally operating heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the first control valve 7, and the outlet end of the first control valve 7, and respectively enters the primary supply water pipe 3; the two paths of supply water are mixed in the primary supply water pipe 3, and then sequentially pass through the primary supply water pipe 3 and the inlet end of the energy storage water tank 5, and enter the energy storage water tank 5; the hot water in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply water pipe 10, and enters the user terminal 9 to heat the users; the hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the system return water; then it returns to the primary return water pipe 2 through the secondary return water pipe 11.

[0051] The remaining one path of return water sequentially passes through the branch return water pipe 6 and the hot water inlet end of the defrosting heat pump unit 1, enters the defrosting heat pump unit 1 to release heat, and after the return water temperature further decreases; then it sequentially passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the second control valve 13, the outlet end of the second control valve 13, and the circulation pipe 12, and also enters the primary return water pipe 2.

[0052] After the two paths of return water that return to the primary return water pipe 2 are mixed in the primary return water pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again, enters the primary circulation pump 4 and is pressurized, and another part of the return water passes through the outlet end of the energy storage water tank 5 and enters the energy storage water tank 5. Thus, the full load condition of a primary defrosting operation is completed.

[0053] (2) Part - load operation function

[0054] 1) Part - load condition of normal operation

[0055] As Figure 1 shown, during the working process of this condition, the heat pump unit 1 is also an air - source heat pump. Since the outdoor air temperature is relatively high, only two heat pump units 1 operate normally, absorb heat from the outdoor air, and heat the system return water from the primary return water pipe 2; the first control valves 7 respectively matched with these two heat pump units 1 are fully open, and the second control valve 13 is closed; the remaining one heat pump unit 1 does not work, the first control valve 7 matched with this heat pump unit 1 is closed, and the second control valve 13 is fully open.

[0056] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 both operate normally; the user terminal 9 also operates normally, and uses the hot water produced by the two normally operating heat pump units 1 to heat the users.

[0057] Under this working condition, the working process of the hot water is as described below:

[0058] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; two of the return water paths respectively enter the two heat pump units 1 that are working properly. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the working heat pump unit 1, enters the working heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the working heat pump unit 1, the inlet end of the first control valve 7, and the outlet end of the first control valve 7, and respectively enters the primary supply pipe 3; the two paths of supply water are mixed in the primary supply pipe 3, and then sequentially pass through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enter the energy storage water tank 5; the hot water in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the user; the hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the return water; then it returns to the primary return pipe 2 through the secondary return pipe 11.

[0059] The remaining one path of return water sequentially passes through the branch return pipe 6, the hot water inlet end of the non-working heat pump unit 1, the hot water outlet end of the non-working heat pump unit 1, the inlet end of the second control valve 13, the outlet end of the second control valve 13, and the circulation pipe 12, and also enters the primary return pipe 2.

[0060] The two paths of return water that return to the primary return pipe 2 are mixed in the primary return pipe 2, and then pass through the inlet end of the primary circulation pump 4, enter the primary circulation pump 4 and the pressure is increased, thus completing a partial load condition of a normal operation.

[0061] 2) Partial load condition of defrosting operation

[0062] As Figure 1 shown, during the working process of this condition, the heat pump unit 1 is also an air source heat pump. Since the outdoor air temperature is relatively high, one heat pump unit 1 does not work, the first control valve 7 matched with this heat pump unit 1 is closed, and the second control valve 13 is fully open. The other two heat pump units 1 are working, but one of the heat pump units 1 reaches the defrosting condition and enters the defrosting process. At this time, the first control valve 7 matched with this defrosting heat pump unit 1 is closed, and the second control valve 13 is fully open; the other heat pump unit 1 is working properly, absorbs heat from the outdoor air, and heats the system return water from the primary return pipe 2; the first control valve 7 matched with this working heat pump unit 1 is fully open, and the second control valve 13 is closed.

[0063] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 are both working properly; the user terminal 9 is also working properly, and uses the hot water produced by one working heat pump unit 1 and the hot water stored in the energy storage water tank 5 to heat the user.

[0064] Under this working condition, the working process of the hot water is as described below:

[0065] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; one path of the return water enters a heat pump unit 1 that is operating normally. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the heat pump unit 1 that is operating normally, enters the heat pump unit 1 that is operating normally and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the heat pump unit 1 that is operating normally, the inlet end of the first control valve 7, and the outlet end of the first control valve 7, and enters the primary supply pipe 3; this path of supply water then sequentially passes through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enters the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the user; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the system return water; and then it returns to the primary return pipe 2 through the secondary return pipe 11.

[0066] The second path of the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the defrosting heat pump unit 1, enters the defrosting heat pump unit 1 and absorbs heat; after the return water temperature further decreases, it then sequentially passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the second control valve 13, the outlet end of the second control valve 13, and the circulation pipe 12, and also enters the primary return pipe 2.

[0067] The third path of the return water sequentially passes through the branch return pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the second control valve 13, the outlet end of the second control valve 13, and the circulation pipe 12, and also enters the primary return pipe 2.

[0068] After the three paths of return water that return to the primary return pipe 2 are mixed in the primary return pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again and enters the primary circulation pump 4 to increase the pressure, and another part of the return water passes through the outlet end of the energy storage water tank 5 and enters the energy storage water tank 5. Thus, a partial load condition of a defrosting operation is completed.

[0069] (3) Intermittent operation function

[0070] During the working process of this function, the heat pump unit 1 is also an air source heat pump. Due to the relatively high outdoor air temperature, all three heat pump units 1 do not operate, and only the hot water stored in the energy storage water tank 5 is used to heat the user; at this time, the first control valve 7 that is respectively matched with these three heat pump units 1 is closed, and the second control valve 13 is fully open;

[0071] The primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, and the hot water stored in the energy storage water tank 5 is used to heat the user.

[0072] The working process of hot water under this function is described as follows:

[0073] As Figure 1 shown, during operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; each path of return water sequentially passes through the branch return water pipe 6, the hot water inlet end of the heat pump unit 1, the hot water outlet end of the heat pump unit 1, the inlet end of the second control valve 13, and the outlet end of the second control valve 13, and respectively enters the circulation pipe 12; after the three paths of return water are mixed in the circulation pipe 12, they return to the primary return water pipe 2 again, and then pass through the inlet end of the primary circulation pump 4 again and enter the primary circulation pump 4 to increase the pressure. Thus, the antifreeze process under the intermittent operation function is completed;

[0074] The hot water stored in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary water supply pipe 10, and enters the user terminal 9 to heat the user; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the system return water; then it sequentially passes through the secondary return water pipe 11, the primary return water pipe 2, and the outlet end of the energy storage water tank 5, and returns to the energy storage water tank 5.

[0075] Embodiment 2

[0076] As Figure 2 shown, this embodiment is also a heat pump system that can avoid and reduce the energy loss caused by water mixing; and can enable the operator to more precisely control the hot water supply temperature, and is used for winter central heating; this heat pump system also uses outdoor air as the low-temperature heat source; the difference from the system shown in Embodiment 1 Figure 1 is that: a shunt three-way regulating valve 14 is used to replace the first control valve 7 and the second control valve 13. The shunt three-way regulating valve 14 is an electric regulating valve and can change the flow direction of water.

[0077] In the system, the connection mode of the shunt three-way regulating valve 14 in the system is: the inlet end of the shunt three-way regulating valve 14 is connected to the hot water outlet end of the heat pump unit 1, the direct current outlet end 15 of the shunt three-way regulating valve 14 is connected to the primary water supply pipe 3, and the bypass outlet end 16 of the shunt three-way regulating valve 14 is connected to the circulation pipe 12.

[0078] Figure 2 The heat pump system shown also has the following operating functions during the winter working process: full load operation function, partial load operation function, and intermittent operation function.

[0079] Under the full-load operation function, there are also the following two operating conditions: the full-load condition of normal operation and the full-load condition of defrosting operation. Under the partial-load operation function, there are also the following two operating conditions: the partial-load condition of normal operation and the partial-load condition of defrosting operation. When working, the heat pump unit 1 uses reverse-cycle hot gas defrosting.

[0080] The working processes under each function are described as follows.

[0081] (1) Full-load operation function

[0082] 1) Full-load condition of normal operation

[0083] During the working process of this condition, the heat pump unit 1 is an air-source heat pump, and both work normally, absorbing heat from the outdoor air and heating the system return water from the primary return pipe 2;

[0084] At this time, the direct-current outlet end 15 of the flow-dividing three-way regulating valve 14 is fully open, and the bypass outlet end 16 of the flow-dividing three-way regulating valve 14 is closed; the primary circulation pump 4 and the secondary circulation pump 8 both work normally; the user terminal 9 also works normally, using the hot water produced by the heat pump unit 1 to heat the users.

[0085] The working process of hot water under this condition is described as follows:

[0086] As Figure 2 shown, when working, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; each path of return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the heat pump unit 1, enters the heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the heat pump unit 1, the inlet end of the flow-dividing three-way regulating valve 14, and the direct-current outlet end 15 of the flow-dividing three-way regulating valve 14, and enters the primary supply pipe 3 respectively; the three paths of supply water are mixed in the primary supply pipe 3, and then sequentially pass through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enter the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, enters the user terminal 9 to heat the users; the hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the return water; then it returns to the primary return pipe 2 through the secondary return pipe 11; and then passes through the inlet end of the primary circulation pump 4 and enters the primary circulation pump 4 to increase the pressure, thus completing a full-load condition of normal operation.

[0087] 2) Full-load condition of defrosting operation

[0088] During the operation of this working condition, the heat pump unit 1 is also an air-source heat pump, and all three heat pump units 1 operate simultaneously. However, two heat pump units 1 operate normally, extracting heat from the outdoor air and heating the system return water from the primary return pipe 2. The direct-current outlet ends 15 of the flow-dividing three-way regulating valves 14 respectively matched with these two heat pump units 1 are fully open, and the bypass outlet ends 16 of the flow-dividing three-way regulating valves 14 are closed. The remaining one heat pump unit 1 enters the defrosting condition. The direct-current outlet end 15 of the flow-dividing three-way regulating valve 14 matched with this defrosting heat pump unit 1 is closed, and the bypass outlet end 16 of the flow-dividing three-way regulating valve 14 is fully open.

[0089] During the operation process, the primary circulation pump 4 and the secondary circulation pump 8 both operate normally. The user terminal 9 also operates normally, using the hot water produced by the two normally operating heat pump units 1 and the hot water stored in the energy storage tank 5 to heat the users.

[0090] The working process of the hot water under this working condition is as described below:

[0091] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths. Two of the return water paths respectively enter the two normally operating heat pump units 1. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the normally operating heat pump unit 1, enters the normally operating heat pump unit 1 and is heated. After the water temperature reaches the required supply water temperature, it becomes the system supply water. Then, it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the flow-dividing three-way regulating valve 14, and the direct-current outlet end 15 of the flow-dividing three-way regulating valve 14, and respectively enters the primary supply pipe 3. The two paths of supply water are mixed in the primary supply pipe 3, and then sequentially pass through the primary supply pipe 3 and the inlet end of the energy storage tank 5, and enter the energy storage tank 5. The hot water in the energy storage tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the users. The hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the system return water. Then, it returns to the primary return pipe 2 through the secondary return pipe 11.

[0092] The remaining one return water path sequentially passes through the branch return pipe 6 and the hot water inlet end of the defrosting heat pump unit 1, enters the defrosting heat pump unit 1 and has heat extracted. After the return water temperature further decreases, it then sequentially passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the flow-dividing three-way regulating valve 14, the bypass outlet end 16 of the flow-dividing three-way regulating valve 14, and the circulation pipe 12, and also enters the primary return pipe 2.

[0093] After the two paths of return water returning to the primary return pipe 2 are mixed in the primary return pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again and enters the primary circulation pump 4 to have its pressure increased. Another part of the return water passes through the outlet end of the energy storage tank 5 and enters the energy storage tank 5. Thus, the full-load condition of one defrosting operation is completed.

[0094] (2) Partial load operation function

[0095] 1) Partial load condition of normal operation

[0096] As Figure 2 shown, during the working process of this condition, the heat pump unit 1 is also an air source heat pump. Since the outdoor air temperature is relatively high, only two heat pump units 1 need to work normally, absorb heat from the outdoor air, and heat the system return water from the primary return pipe 2. The direct current outlet ends 15 of the flow splitting three-way control valves 14 respectively matched with these two heat pump units 1 are fully open, and the bypass outlet ends 16 of the flow splitting three-way control valves 14 are closed. The remaining one heat pump unit 1 does not work, the direct current outlet end 15 of the flow splitting three-way control valve 14 matched with this non-working heat pump unit 1 is closed, and the bypass outlet end 16 of the flow splitting three-way control valve 14 is fully open.

[0097] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 both work normally; the user terminal 9 also works normally, and uses the hot water produced by the two normally working heat pump units 1 to heat the users.

[0098] The working process of the hot water under this condition is as follows:

[0099] During work, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; two of the return water paths respectively enter the two normally working heat pump units 1. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the normally working heat pump unit 1, enters the normally working heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally working heat pump unit 1, the inlet end of the flow splitting three-way control valve 14, and the direct current outlet end 15 of the flow splitting three-way control valve 14, and respectively enters the primary supply pipe 3; the two supply water paths are mixed in the primary supply pipe 3, and then sequentially pass through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enter the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the users; the hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the return water; then it returns to the primary return pipe 2 through the secondary return pipe 11. The remaining one return water path sequentially passes through the branch return pipe 6, the hot water inlet end of the non-working heat pump unit 1, the hot water outlet end of the non-working heat pump unit 1, the inlet end of the flow splitting three-way control valve 14, the bypass outlet end 16 of the flow splitting three-way control valve 14, and the circulation pipe 12, and also enters the primary return pipe 2.

[0100] After the two-way return water in the primary return pipe 2 is mixed in the primary return pipe 2, it then passes through the inlet end of the primary circulation pump 4 and enters the primary circulation pump 4 to have its pressure boosted. Thus, a partial load condition of a normal operation cycle is completed.

[0101] 2) Partial load condition of defrost operation

[0102] As Figure 2 shown, during the working process of this condition, the heat pump unit 1 is also an air source heat pump. Due to the relatively high outdoor air temperature, one heat pump unit 1 is not operating, and the direct current outlet end 15 of the diverting three-way regulating valve 14 that is matched with this non-operating heat pump unit 1 is closed, while the bypass outlet end 16 of the diverting three-way regulating valve 14 is fully open.

[0103] In addition, two other heat pump units 1 are operating, but one of the heat pump units 1 reaches the defrost condition and enters the defrost process. At this time, the direct current outlet end 15 of the diverting three-way regulating valve 14 that is matched with this defrosting heat pump unit 1 is closed, and the bypass outlet end 16 of the diverting three-way regulating valve 14 is fully open; the other heat pump unit 1 is operating normally, absorbing heat from the outdoor air and heating the system return water from the primary return pipe 2; the direct current outlet end 15 of the diverting three-way regulating valve 14 that is matched with this normally operating heat pump unit 1 is fully open, and the bypass outlet end 16 of the diverting three-way regulating valve 14 is closed.

[0104] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, using the hot water produced by one normally operating heat pump unit 1 and the hot water stored in the energy storage water tank 5 to heat the users.

[0105] The working process of the hot water under this condition is as described below:

[0106] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; one of the paths of the return water enters one normally operating heat pump unit 1. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the normally operating heat pump unit 1 and enters the normally operating heat pump unit 1 to be heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the diverting three-way regulating valve 14, and the direct current outlet end 15 of the diverting three-way regulating valve 14 and enters the primary supply pipe 3; this path of supply water then sequentially passes through the primary supply pipe 3 and the inlet end of the energy storage water tank 5 and enters the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10 and enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the system return water; then it returns to the primary return pipe 2 through the secondary return pipe 11.

[0107] The second return water passes through the branch return water pipe 6 and the hot water inlet end of the defrosting heat pump unit 1 in sequence, enters the defrosting heat pump unit 1 and absorbs heat; after the return water temperature further decreases, it then passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, the bypass outlet end 16 of the flow dividing three-way regulating valve 14, and the circulating pipe 12 in sequence, and also enters the primary return water pipe 2.

[0108] The third return water passes through the branch return water pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, the bypass outlet end 16 of the flow dividing three-way regulating valve 14, and the circulating pipe 12 in sequence, and also enters the primary return water pipe 2.

[0109] After the three-way return water returning to the primary return water pipe 2 is mixed in the primary return water pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again and enters the primary circulation pump 4 to increase the pressure, and another part of the return water returns to the energy storage water tank 5 through the outlet end of the energy storage water tank 5, thus completing a part of the load condition of a defrosting operation.

[0110] (3) Intermittent operation function

[0111] During the working process of this function, the heat pump unit 1 is also an air source heat pump. Due to the relatively high outdoor air temperature, all three heat pump units 1 do not work, and only the hot water stored in the energy storage water tank 5 is used for heating the users; at this time, the direct current outlet end 15 of the flow dividing three-way regulating valve 14 respectively matched with these three heat pump units 1 is closed, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is fully opened.

[0112] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 both work normally; the user terminal 9 also works normally, and the hot water stored in the energy storage water tank 5 is used for heating the users.

[0113] The working process of the hot water under this function is as described below:

[0114] As Figure 2 shown, during operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; the return water passes through the branch return water pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 in sequence, and respectively enters the circulating pipe 12. After the three paths of return water entering the circulating pipe 12 are mixed in the circulating pipe 12, they return to the primary return water pipe 2 again, pass through the inlet end of the primary circulation pump 4 again, and enter the primary circulation pump 4 to increase the pressure. Thus, the antifreeze process under an intermittent operation function is completed;

[0115] The hot water stored in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary water supply pipe 10, and enters the user terminal 9 to heat the user; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the system return water; then it passes through the secondary return water pipe 11, the primary return water pipe 2, and the outlet end of the energy storage water tank 5 in sequence, and returns to the energy storage water tank 5.

[0116] Embodiment 3

[0117] As Figure 3 shown, this embodiment is also a heat pump system that can avoid and reduce the energy loss caused by water mixing; and can enable the operator to more accurately control the hot water supply temperature, and is used for winter central heating; this heat pump system also uses outdoor air as the low-temperature heat source; different from the system shown in Embodiment 1 Figure 1 The difference is that a shunt three-way regulating valve 14 is used to replace the first control valve 7 and the second control valve 13. The shunt three-way regulating valve 14 is an electric regulating valve that can change the water flow direction.

[0118] In the system, the connection method of the shunt three-way regulating valve 14 is: the inlet end of the shunt three-way regulating valve 14 is connected to the hot water outlet end of the heat pump unit 1, the direct current outlet end 15 of the shunt three-way regulating valve 14 is connected to the circulation pipe 12, and the bypass outlet end 16 of the shunt three-way regulating valve 14 is connected to the primary water supply pipe 3.

[0119] Figure 3 The heat pump system shown also has the following operating functions during winter operation: full load operation function, partial load operation function, and intermittent operation function.

[0120] Under the full load operation function, there are also the following two operating conditions: the full load condition of normal operation, and the full load condition of defrosting operation. Under the partial load operation function, there are also the following two operating conditions: the partial load condition of normal operation, and the partial load condition of defrosting operation.

[0121] The working processes under each function are described as follows.

[0122] (1) Full load operation function

[0123] 1) Full load condition of normal operation

[0124] During the working process of this condition, the heat pump unit 1 is an air source heat pump and works normally, absorbs heat from the outdoor air, and heats the system return water from the primary return water pipe 2;

[0125] At this time, the direct current outlet end 15 of the flow dividing three-way regulating valve 14 is closed, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is fully open; the primary circulation pump 4 and the secondary circulation pump 8 are both working normally; the user terminal 9 is also working normally, and the hot water produced by the heat pump unit 1 is used to heat the users.

[0126] Under this working condition, the working process of the hot water is as follows:

[0127] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; each path of the return water sequentially passes through the branch return water pipe 6 and the hot water inlet end of the heat pump unit 1, enters the heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14, and enters the primary supply water pipe 3 respectively; after the three paths of supply water are mixed in the primary supply water pipe 3, they sequentially pass through the primary supply water pipe 3 and the inlet end of the energy storage water tank 5, and enter the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply water pipe 10, enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the return water; then it returns to the primary return water pipe 2 through the secondary return water pipe 11; and then passes through the inlet end of the primary circulation pump 4 and enters the primary circulation pump 4 to increase the pressure, thus completing a full load working condition of a normal operation.

[0128] 2) Full load working condition of defrosting operation

[0129] During the working process of this working condition, the heat pump unit 1 is also an air source heat pump, and all three heat pump units 1 work simultaneously; however, two heat pump units 1 work normally, absorb heat from the outdoor air, and heat the system return water from the primary return water pipe 2; the direct current outlet end 15 of the flow dividing three-way regulating valve 14 respectively matched with these two heat pump units 1 is closed, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is fully open; the remaining one heat pump unit 1 enters the defrosting working condition, the direct current outlet end 15 of the flow dividing three-way regulating valve 14 matched with this defrosting heat pump unit 1 is fully open, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is closed; and this heat pump unit 1 uses reverse cycle hot gas defrosting.

[0130] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 both work normally; the user terminal 9 also works normally, and the hot water produced by the two normally working heat pump units 1 and the hot water in the energy storage water tank 5 are used to heat the users.

[0131] Under this working condition, the working process of the hot water is as follows:

[0132] During operation, after the return water is pumped out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; two of the return water paths respectively enter the two heat pump units 1 that are operating normally. At this time, the return water sequentially passes through the branch return water pipe 6 and the hot water inlet end of the normally operating heat pump unit 1, enters the normally operating heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14, and respectively enters the primary supply water pipe 3; the two-way supply water is mixed in the primary supply water pipe 3, and then sequentially passes through the primary supply water pipe 3 and the inlet end of the energy storage water tank 5, and enters the energy storage water tank 5; the hot water in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply water pipe 10, and enters the user terminal 9 to heat the user; the hot water releases heat at the user terminal 9, and after the temperature drops, it becomes the system return water; then it returns to the primary return water pipe 2 through the secondary return water pipe 11.

[0133] The remaining one-way return water sequentially passes through the branch return water pipe 6 and the hot water inlet end of the defrosting heat pump unit 1, enters the defrosting heat pump unit 1 and is absorbed for heat; after the return water temperature further decreases; then it sequentially passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, the direct current outlet end 15 of the flow dividing three-way regulating valve 14, and the circulation pipe 12, and also enters the primary return water pipe 2.

[0134] After the two-way return water returning to the primary return water pipe 2 is mixed in the primary return water pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again and enters the primary circulation pump 4 to increase the pressure; another part of the return water passes through the outlet end of the energy storage water tank 5 and returns to the energy storage water tank 5; thus, the full load condition of a single defrosting operation is completed.

[0135] (2) Partial load operation function

[0136] 1) Partial load condition of normal operation

[0137] As Figure 3 shown, during the operation process of this condition, the heat pump unit 1 is also an air source heat pump. Since the outdoor air temperature is relatively high, only two heat pump units 1 need to operate normally, absorb heat from the outdoor air, and heat the system return water from the primary return water pipe 2; the direct current outlet end 15 of the flow dividing three-way regulating valve 14 respectively matched with these two heat pump units 1 is closed, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is opened; the remaining another heat pump unit 1 does not work, and the direct current outlet end 15 of the flow dividing three-way regulating valve 14 matched with this non-operating heat pump unit 1 is opened, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is closed.

[0138] During operation, the primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, and the hot water produced by the two normally operating heat pump units 1 is used to heat the users.

[0139] Under this working condition, the working process of the hot water is as described below:

[0140] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; two of the return water paths respectively enter the two normally operating heat pump units 1. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the normally operating heat pump unit 1, enters the normally operating heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14, and respectively enters the primary supply pipe 3; the two-way supply water is mixed in the primary supply pipe 3, and then sequentially passes through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enters the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the return water; then it returns to the primary return pipe 2 through the secondary return pipe 11. The remaining one-way return water sequentially passes through the branch return pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, the direct current outlet end 15 of the flow dividing three-way regulating valve 14, and the circulation pipe 12, and also enters the primary return pipe 2.

[0141] The two-way return water returning to the primary return pipe 2 is mixed in the primary return pipe 2, and then passes through the inlet end of the primary circulation pump 4 and enters the primary circulation pump 4 to increase the pressure, thus completing a partial load condition of a normal operation.

[0142] 2) Partial load condition of defrosting operation

[0143] As Figure 3 shown, during the working process of this condition, the heat pump unit 1 is also an air source heat pump. Since the outdoor air temperature is relatively high, one heat pump unit 1 is not operating, and the direct current outlet end 15 of the flow dividing three-way regulating valve 14 matched with this non-operating heat pump unit 1 is fully open, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is closed.

[0144] The other two heat pump units 1 are operating, but one of the heat pump units 1 meets the defrosting condition and enters the defrosting process. At this time, the direct current outlet end 15 of the shunt three-way regulating valve 14 that matches this defrosting heat pump unit 1 is fully open, and the bypass outlet end 16 of the shunt three-way regulating valve 14 is closed; the other heat pump unit 1 is operating normally, absorbing heat from the outdoor air and heating the system return water from the primary return pipe 2; the direct current outlet end 15 of the shunt three-way regulating valve 14 that matches this normally operating heat pump unit 1 is closed, and the bypass outlet end 16 of the shunt three-way regulating valve 14 is fully open.

[0145] During the working process, the primary circulation pump 4 and the secondary circulation pump 8 are both operating normally; the user terminal 9 is also operating normally, using the hot water produced by one normally operating heat pump unit 1 and the hot water stored in the energy storage water tank 5 to heat the users.

[0146] The working process of the hot water under this working condition is as described below:

[0147] During operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return pipe 2 and is divided into three paths; one path of the return water enters one normally operating heat pump unit 1. At this time, the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the normally operating heat pump unit 1, enters the normally operating heat pump unit 1 and is heated; after the water temperature reaches the required supply water temperature, it becomes the system supply water; then it sequentially passes through the hot water outlet end of the normally operating heat pump unit 1, the inlet end of the shunt three-way regulating valve 14, and the bypass outlet end 16 of the shunt three-way regulating valve 14, and enters the primary supply pipe 3; this path of supply water then sequentially passes through the primary supply pipe 3 and the inlet end of the energy storage water tank 5, and enters the energy storage water tank 5; the hot water in the energy storage water tank 5 then sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary supply pipe 10, and enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and the temperature drops, it becomes the system return water; then it returns to the primary return pipe 2 through the secondary return pipe 11.

[0148] The second path of the return water sequentially passes through the branch return pipe 6 and the hot water inlet end of the defrosting heat pump unit 1, enters the defrosting heat pump unit 1 and is absorbed for heat; after the return water temperature further decreases; then it sequentially passes through the hot water outlet end of the defrosting heat pump unit 1, the inlet end of the shunt three-way regulating valve 14, the direct current outlet end 15 of the shunt three-way regulating valve 14, and the circulation pipe 12, and also enters the primary return pipe 2.

[0149] The third path of the return water sequentially passes through the branch return pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the shunt three-way regulating valve 14, the direct current outlet end 15 of the shunt three-way regulating valve 14, and the circulation pipe 12, and also enters the primary return pipe 2.

[0150] After the three-way return water in the primary return water pipe 2 mixes in the primary return water pipe 2, a part of the return water passes through the inlet end of the primary circulation pump 4 again and enters the primary circulation pump 4 to have its pressure boosted. Another part of the return water passes through the outlet end of the energy storage water tank 5 and returns to the energy storage water tank 5. Thus, the partial load condition of a defrosting operation is completed.

[0151] (3) Intermittent operation function

[0152] During the operation of this function, the heat pump unit 1 is also an air source heat pump. Since the outdoor air temperature is relatively high, all three heat pump units 1 do not operate, and only the hot water stored in the energy storage water tank 5 is used for heating the users. At this time, the DC outlet end 15 of the flow dividing three-way regulating valve 14 respectively matched with these three heat pump units 1 is fully open, and the bypass outlet end 16 of the flow dividing three-way regulating valve 14 is closed.

[0153] During the operation, the primary circulation pump 4 and the secondary circulation pump 8 both operate normally; the user terminal 9 also operates normally, and the hot water stored in the energy storage water tank 5 is used for heating the users.

[0154] The working process of the hot water under this function is as described below:

[0155] As Figure 3 shown, during operation, after the return water is pressed out from the outlet end of the primary circulation pump 4, it enters the primary return water pipe 2 and is divided into three paths; the return water sequentially passes through the branch return water pipe 6, the hot water inlet end of the non-operating heat pump unit 1, the hot water outlet end of the non-operating heat pump unit 1, the inlet end of the flow dividing three-way regulating valve 14, and the DC outlet end 15 of the flow dividing three-way regulating valve 14, and respectively enters the circulation pipe 12. After the three paths of return water entering the circulation pipe 12 mix in the circulation pipe 12, they return to the primary return water pipe 2 again, pass through the inlet end of the primary circulation pump 4 again, and enter the primary circulation pump 4 to have its pressure boosted. Thus, the antifreeze process under an intermittent operation condition is completed;

[0156] The hot water stored in the energy storage water tank 5 sequentially passes through the inlet end of the secondary circulation pump 8, the outlet end of the secondary circulation pump 8, and the secondary water supply pipe 10, enters the user terminal 9 to heat the users; after the hot water releases heat at the user terminal 9 and its temperature drops, it becomes the system return water; then it sequentially passes through the secondary return water pipe 11, the primary return water pipe 2, and the outlet end of the energy storage water tank 5, and returns to the energy storage water tank 5.

Claims

1. A heat pump system, comprising at least two heat pump units (1), a primary water return pipe (2), a primary water supply pipe (3), a primary circulation pump (4), an energy storage water tank (5), and a first control valve (7) respectively matched with each heat pump unit (1), wherein: The heat pump system further comprises a circulation pipe (12) and a second control valve (13) respectively matched with each heat pump unit (1); The hot water outlet of the heat pump unit (1) is connected to the inlet of the energy storage water tank (5) through the inlet of the first control valve (7), the outlet of the first control valve (7), and the primary water supply pipe (3) in sequence; The hot water inlet end of the heat pump unit (1) is connected to the outlet end of the energy storage water tank (5) through the branch return pipe (6) and the primary return pipe (2) in sequence; The primary circulation pump (4) is arranged on the primary return pipe (2); that is, the outlet end of the primary circulation pump (4) is connected to the hot water inlet end of the heat pump unit (1) through the primary return pipe (2) and the branch return pipe (6) in sequence; the inlet end of the primary circulation pump (4) is connected to the outlet end of the energy storage water tank (5) through the primary return pipe (2); The inlet end of the second control valve (13) is connected to a pipeline between the inlet end of the first control valve (7) and the hot water outlet end of the heat pump unit (1), and the outlet end of the second control valve (13) is connected to a primary return water pipe (2) between the inlet end of a primary circulation pump (4) and the outlet end of an energy storage water tank (5) via a circulation pipe (12).

2. A heat pump system, comprising at least two heat pump units (1), a primary water return pipe (2), a primary water supply pipe (3), a primary circulation pump (4), and an energy storage water tank (5), characterized in that: The heat pump system further comprises a circulation pipe (12) and a flow-dividing three-way regulating valve (14) respectively matched with each heat pump unit (1); The hot water outlet of the heat pump unit (1) is connected to the inlet of the energy storage water tank (5) through the inlet of the diverting three-way regulating valve (14), the direct current outlet (15) of the diverting three-way regulating valve (14), and the primary water supply pipe (3); The hot water inlet end of the heat pump unit (1) is connected to the outlet end of the energy storage water tank (5) through the branch return pipe (6) and the primary return pipe (2) in sequence; The primary circulation pump (4) is arranged on the primary return pipe (2); that is, the outlet end of the primary circulation pump (4) is connected to the hot water inlet end of the heat pump unit (1) through the primary return pipe (2) and the branch return pipe (6) in sequence; the inlet end of the primary circulation pump (4) is connected to the outlet end of the energy storage water tank (5) through the primary return pipe (2); The bypass outlet end (16) of the diverting three-way regulating valve (14) is connected to the primary return water pipe (2) between the inlet end of the primary circulation pump (4) and the outlet end of the energy storage water tank (5) through the circulation pipe (12).

3. A heat pump system, comprising at least two heat pump units (1), a primary water return pipe (2), a primary water supply pipe (3), a primary circulation pump (4), and an energy storage water tank (5), characterized in that: The heat pump system further comprises a circulation pipe (12) and a flow-dividing three-way regulating valve (14) respectively matched with each heat pump unit (1); The hot water outlet of the heat pump unit (1) is connected to the inlet of the energy storage water tank (5) through the inlet of the diverting three-way regulating valve (14), the bypass outlet (16) of the diverting three-way regulating valve (14), and the primary water supply pipe (3); The hot water inlet end of the heat pump unit (1) is connected to the outlet end of the energy storage water tank (5) through the branch return pipe (6) and the primary return pipe (2) in sequence; The primary circulation pump (4) is arranged on the primary return pipe (2); that is, the outlet end of the primary circulation pump (4) is connected to the hot water inlet end of the heat pump unit (1) through the primary return pipe (2) and the branch return pipe (6) in sequence; the inlet end of the primary circulation pump (4) is connected to the outlet end of the energy storage water tank (5) through the primary return pipe (2); The direct current outlet end (15) of the diverting three-way regulating valve (14) is connected to the primary return water pipe (2) between the inlet end of the primary circulation pump (4) and the outlet end of the energy storage water tank (5) through the circulation pipe (12).

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