CN107655124B - Air source heat pump system of non-interrupted heat supply of defrosting - Google Patents

Abstract

The invention relates to the technical field of air source heat pump systems, in particular to an air source heat pump system for uninterrupted heat supply for defrosting, which includes a compressor, a first reversing valve, and a first heat exchanger sequentially arranged on a refrigerant circuit , one-way valve, first solenoid valve, second heat exchanger, third solenoid valve and first throttling mechanism; wherein, the first heat exchanger is located indoors, and the second heat exchanger is located outdoors A third heat exchanger is arranged in series, and a second reversing valve is arranged between the first heat exchanger, the second heat exchanger, and the third heat exchanger. The air source heat pump system for defrosting uninterrupted heating provided by the present invention, due to the addition of a set of outdoor heat exchange equipment (the third heat exchanger), effectively increases the heat exchange area of the outdoor heat exchanger and improves the efficiency of the heat pump. System energy efficiency ratio; under winter heating and defrosting conditions, the heat pump unit can realize the defrosting process and still supply heat to the room, which improves the indoor thermal comfort.

Description

An air source heat pump system for defrosting uninterrupted heating

technical field

The invention relates to the technical field of air-source heat pump systems, in particular to an air-source heat pump system for non-interruptible heat supply during defrosting.

Background technique

The air source heat pump has the advantages of using inexhaustible air as a low-level heat source, wide application range, and high equipment utilization rate. Air source heat pump performance is greatly affected by the outdoor environment. In winter, when the air source heat pump unit supplies heat to the room, when the temperature of the outdoor coil is lower than 0°C and lower than the dew point temperature of the outdoor air, the outdoor coil will frost. The frosting of the air source heat pump has two main effects on the operation of the heat pump: ①A large amount of frost accumulation will reduce the heat transfer coefficient of the evaporator; ②The frosting hinders the gas flow between the finned coils of the outdoor evaporator, and the energy loss of the fan increases. As the frost layer on the wall of the outdoor heat exchanger increases, the evaporation temperature of the outdoor heat exchanger decreases, the heating capacity of the unit decreases, the performance of the fan decreases, the input current increases, and the coefficient of heating performance decreases. In severe cases, the compressor will stop running, so that the unit cannot normal work. Therefore, periodic defrosting has become a necessary means for the normal operation of air source heat pumps. At present, the effective defrosting method commonly used is reverse cycle defrosting, but this defrosting method must be stopped for defrosting, and there are problems such as insufficient low-level heat source, discontinuous heating, and poor thermal comfort of the indoor environment. Therefore, in order to improve the stability of system operation and ensure the thermal comfort of the environment, this paper proposes an air source heat pump system with non-interruptible heating for defrosting.

Contents of the invention

(1) Technical problems to be solved

The purpose of the present invention is to provide an air source heat pump system with non-interruptible heating for defrosting, aiming to solve the problem that the air source heat pump in the prior art must be shut down during defrosting, the heating is not continuous, the thermal comfort of the indoor environment is poor and the system is running The problem of poor stability.

(2) Technical solutions

In order to solve the above technical problems, the present invention provides an air source heat pump system for defrosting uninterrupted heat supply, which includes a compressor, a first reversing valve, a first heat exchanger, a one-way valve, a first solenoid valve, a second heat exchanger, a third solenoid valve, and a first throttling mechanism; wherein, the first heat exchanger is located indoors, and the second heat exchanger located outdoors is provided in series with In the third heat exchanger, a second reversing valve is arranged between the first heat exchanger, the second heat exchanger, and the third heat exchanger.

In one embodiment of the present invention, a second throttling mechanism is arranged in parallel on the one-way valve.

In one embodiment of the present invention, a gas-liquid separator is also included, and the gas-liquid separator is arranged on the air return pipeline of the compressor.

In one embodiment of the present invention, a fourth solenoid valve and a third throttling mechanism are arranged in parallel on the pipeline where the third solenoid valve and the first throttling mechanism are located.

In one embodiment of the present invention, a second solenoid valve is arranged in parallel on the pipeline where the first solenoid valve, the second heat exchanger and the third throttling mechanism are located.

In one embodiment of the present invention, the pipeline between the third solenoid valve and the first throttle mechanism communicates with the pipeline between the second solenoid valve and the third throttle mechanism .

In one embodiment of the present invention, a fifth electromagnetic valve is arranged in parallel on the second reversing valve.

In one embodiment of the present invention, both the first reversing valve and the second reversing valve are four-way reversing valves.

In one embodiment of the present invention, both the second heat exchanger and the third heat exchanger are located outdoors.

(3) Beneficial effects

Compared with the prior art, the technical solution of the present invention has the following beneficial effects: 1. Under the working conditions of cooling in summer and heating in winter, due to the addition of a set of outdoor heat exchange equipment (the third heat exchanger), the effective increase The heat exchange area of the outdoor heat exchanger is increased, and the energy efficiency ratio of the heat pump system is improved; 2. Under the heating and defrosting conditions in winter, the heat pump unit can realize the defrosting process and still supply heat to the room, which improves the indoor thermal comfort; 3. The frosting process uses outdoor air as a heat source, which overcomes the lack of low-level heat sources in previous defrosting, so it has the characteristics of energy saving and high defrosting safety; 4. The four-way reversing valve connected to the compressor exhaust port of this system is only used in winter and summer Reversal is only required for conversion, and there is no problem of switching the roles of indoor and outdoor units as evaporators and condensers, which is conducive to improving system safety and reliability.

Description of drawings

Fig. 1 is a schematic diagram of an air source heat pump system for defrosting non-interruptible heating according to an embodiment of the present invention;

Fig. 2 is a refrigeration principle diagram of an air source heat pump system for defrosting non-interruptible heating in Fig. 1;

Fig. 3 is a heating principle diagram of an air source heat pump system for non-interruptible defrosting heating in Fig. 1;

Fig. 4 is a schematic diagram of a winter defrosting and heating system of an air source heat pump system with non-interruptible defrosting heating in Fig. 1;

Fig. 5 is another schematic diagram of defrosting and heating in winter of an air source heat pump system with non-interruptible defrosting heating in Fig. 1;

Among them, 1-compressor; 2-first reversing valve; 3-first heat exchanger; 4-second throttling mechanism; 5-one-way valve; 6-first solenoid valve; 7-second solenoid valve ; 8-the second reversing valve; 9-the second heat exchanger; 10-the third solenoid valve; 11-the first throttle mechanism; 12-the fourth solenoid valve; 13-the third throttle mechanism; 14-the first Three heat exchangers; 15-fifth solenoid valve; 16-gas-liquid separator.

Detailed ways

Embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but should not be used to limit the scope of the present invention.

In the description of the present invention, unless otherwise specified, "plurality" means two or more; unless otherwise specified, "notch-shaped" means a shape other than an even cross-section. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" etc. is Based on the orientation or positional relationship shown in the drawings, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood To limit the present invention. In addition, the terms "first", "second", "third", etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection. Connected, or integrally connected; it may be mechanically connected or electrically connected; it may be directly connected or indirectly connected through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention depending on the specific circumstances.

Referring to Fig. 1 to Fig. 5, the present invention provides an air source heat pump system for defrosting uninterrupted heat supply, which includes a compressor 1, a first reversing valve 2, a first reversing valve arranged in turn on the refrigerant circuit Heater 3, one-way valve 5, first solenoid valve 6, second heat exchanger 9, third solenoid valve 10 and first throttling mechanism 11; wherein, the first heat exchanger 3 is located indoors, and the second heat exchanger is located outdoors A third heat exchanger 14 is arranged in series on the second heat exchanger 9 , and a second reversing valve 8 is arranged between the first heat exchanger 3 , the second heat exchanger 9 and the third heat exchanger 14 . A second throttling mechanism 4 is arranged in parallel on the one-way valve 5 . On the pipeline where the third solenoid valve 10 and the first throttling mechanism 11 are located, a fourth solenoid valve 12 and a third throttling mechanism 13 are arranged in parallel. A second electromagnetic valve 7 is arranged in parallel on the pipeline where the first electromagnetic valve 6 , the second heat exchanger 9 and the third throttling mechanism 13 are located. The pipeline between the third solenoid valve 10 and the first throttle mechanism 11 is in communication with the pipeline between the second solenoid valve 7 and the third throttle mechanism 13 . A fifth solenoid valve 15 is arranged in parallel on the second reversing valve 8 .

Compared with the prior art, the air source heat pump system for defrosting non-interruptible heating provided by the present invention has the following advantages: 1. Under the conditions of cooling in summer and heating in winter, due to the addition of a set of outdoor heat exchange equipment (The third heat exchanger), which effectively increases the heat exchange area of the outdoor heat exchanger and improves the energy efficiency ratio of the heat pump system; 2. Under the heating and defrosting conditions in winter, the heat pump unit can realize the defrosting process and still supply heat to the room , which improves indoor thermal comfort; 3. The defrosting process uses outdoor air as a heat source, which overcomes the problem of lack of low-level heat sources in previous defrosting, so it has the characteristics of energy saving and high defrosting safety; 4. The compressor exhaust of this system The four-way reversing valve connected to the air port needs to be reversed only in winter and summer, and there is no problem with the role conversion of indoor and outdoor units as evaporators and condensers, which is conducive to improving system safety and reliability.

The above system switches the opening and closing of the first reversing valve 2, the second reversing valve 8, the first solenoid valve 6, the second solenoid valve 7, the third solenoid valve 10, the fourth solenoid valve 12, and the fifth solenoid valve 15. Realize three operating modes: normal cooling, normal heating, and defrosting heating. During cooling in summer and normal heating in winter, double outdoor heat exchangers (second heat exchanger 9 and third heat exchanger 14) equipped with fans can ensure that the heat pump has a larger outdoor heat exchange area, thereby ensuring cooling and cooling. Efficient operation in heating conditions. When the outdoor heat exchanger of the heat pump for heating in winter needs to be defrosted, the indoor heat exchanger (the first heat exchanger 3) and the equipped fan can dissipate heat to the room through the action of the second reversing valve 8 and its solenoid valve. Use the subcooled refrigerant liquid from the indoor heat exchanger (the first heat exchanger 3) to defrost one of the second heat exchanger 9 equipped with a fan and the third heat exchanger 14 equipped with a fan, and in addition One acts as an evaporator to take heat from the outside environment. Therefore, the system can realize normal heating and cooling, and can realize non-interrupted heat supply to the building by the heat pump during the defrosting period, ensuring the stability of system operation and indoor thermal comfort.

As a specific embodiment of the defrosting air source heat pump system provided by the present invention, it further includes a gas-liquid separator 16 , which is arranged on the air return pipeline of the compressor 1 .

As a specific embodiment of a defrosting air source heat pump system provided by the present invention, the first reversing valve 2 and the second reversing valve 8 are both four-way reversing valves. The four-way reversing valve connected to the exhaust port of the compressor in this system needs to be reversed only in winter and summer, and there is no problem with the role conversion of indoor and outdoor units as evaporators and condensers, which is conducive to improving system safety and reliability.

As a specific embodiment of the defrosting air source heat pump system provided by the present invention, both the second heat exchanger 9 and the third heat exchanger 14 are located outdoors. Due to the addition of a set of outdoor heat exchange equipment (the third heat exchanger), the heat exchange area of the outdoor heat exchanger is effectively increased, and the energy efficiency ratio of the heat pump system is improved.

An air source heat pump system for uninterrupted heating in defrosting of the present invention, when working under different working conditions:

1. Normal cooling mode in summer

Referring to Fig. 2, the first solenoid valve 6 is closed. The operation of the system is as follows: the refrigerant from the compressor 1 flows through the first reversing valve 2, and then the refrigerant flows into two paths. One of them flows through the fifth solenoid valve 15 and enters the third heat exchanger 14 equipped with a fan to condense and release heat, then flows through the fourth solenoid valve 12, and the other path flows through the second reversing valve 8 and enters the third heat exchanger equipped with a fan. The second heat exchanger 9 condenses and releases heat, then flows through the third solenoid valve 10, joins at the entrance of the second solenoid valve 7, and flows through the second throttling mechanism 4 to throttle and reduce pressure. The heat absorber 3 absorbs heat, then flows through the first reversing valve 2, the gas-liquid separator 16 in sequence, and finally returns to the compressor 1 to be compressed again.

2. Normal heating mode in winter

Referring to Fig. 3, the first solenoid valve 6, the third solenoid valve 10, and the fourth solenoid valve 12 are closed. The system operates as follows: the refrigerant from the compressor 1 flows through the first reversing valve 2, enters the first heat exchanger 3 equipped with a fan to condense and release heat, and then flows through the one-way valve 5 and the second solenoid valve 7 in sequence , since then the refrigerant flows into two paths. One of them passes through the third throttling mechanism 13 to throttle and reduce pressure, absorbs heat in the second heat exchanger 9 equipped with a fan, and then flows through the second reversing valve 8 to one end of the fifth electromagnetic valve 15 in sequence; Flow through the first throttling mechanism 11 to throttle and reduce pressure, absorb heat in the third heat exchanger 14 equipped with a fan, and flow through the fifth solenoid valve 15, so far the two refrigerants merge, and then flow through the first reversing valve together 2. The gas-liquid separator 16 finally returns to the compressor 1 to be compressed again.

3. Winter defrosting and heating mode A (the second heat exchanger 9 defrosting)

Referring to Fig. 4, the second solenoid valve 7, the fourth solenoid valve 12, and the fifth solenoid valve 15 are closed. The inlet end of the second heat exchanger 9 is connected with the outlet end of the first electromagnetic valve 6, and the system operates as follows: the refrigerant from the compressor 1 flows through the first reversing valve 2, and enters the first heat exchanger equipped with a fan. After condensing and releasing heat in the device 3, it becomes a subcooled refrigerant, and then flows through the check valve 5, the first solenoid valve 6, and the second reversing valve 8 in sequence, and then enters the second heat exchanger 9 equipped with a fan to release heat and defrost Then it flows through the third solenoid valve 10, throttles down the pressure and lowers the temperature through the first throttling mechanism 11, enters the third heat exchanger 14 equipped with a fan to absorb heat from the outdoor environment, and then flows through the second reversing valve 8 in sequence. , the gas-liquid separator 16, and finally returns to the compressor 1 to be compressed again.

4. Winter defrosting and heating mode B (defrosting of the third heat exchanger 14)

Referring to FIG. 5 , the second solenoid valve 7 , the third solenoid valve 10 and the fifth solenoid valve 15 are closed. The inlet end of the third heat exchanger 14 is connected with the outlet end of the first electromagnetic valve 6, and the system operates as follows: the refrigerant from the compressor 1 flows through the first reversing valve 2, and enters the first heat exchanger equipped with a fan. After condensing and releasing heat in the device 3, the supercooled refrigerant flows through the one-way valve 5, the first solenoid valve 6, and the second reversing valve 8 in sequence, and enters the third heat exchanger 14 equipped with a fan to release heat and defrost. Flow through the fourth electromagnetic valve 12, throttling in the third throttling mechanism 13 to reduce pressure and temperature, enter the second heat exchanger 9 equipped with a fan to absorb heat from the environment, and then flow through the second reversing valve 8, The first reversing valve 2, the gas-liquid separator 16, and finally return to the compressor 1 to be compressed again.

An air-source heat pump system for defrosting non-interruptible heating provided by the present invention has the following technical effects: (1) Under the conditions of cooling in summer and heating in winter, due to the addition of a set of outdoor heat exchange equipment (the third heat exchange 14), which effectively increases the heat exchange area of the outdoor heat exchanger and improves the energy efficiency ratio of the heat pump system; (2) In winter heating and defrosting conditions, the heat pump unit can realize the defrosting process and still supply heat to the room, which improves the energy efficiency of the heat pump system. Indoor thermal comfort; (3) Traditional air source heat pumps lack low-level heat sources, resulting in long defrosting cycles, high energy consumption (the heat of defrosting mainly comes from the compressor), and even bring about safety problems in the operation of heat pumps. This system, in essence, uses outdoor air as the heat source in the defrosting process, which overcomes the lack of low-level heat sources in previous defrosting, so it has the characteristics of energy saving and high defrosting safety; (4) Traditional defrosting relies on the exhaust port of the compressor to connect The four-way reversing valve is reversing for defrosting, and the role of the indoor and outdoor units as evaporators and condensers is switched, resulting in frequent redistribution of refrigerant and lubricating oil in the system, and the reversing frequency of the four-way reversing valve is high. The four-way reversing valve connected to the exhaust port of the compressor in this system needs to be reversed only in winter and summer, and there is no problem with the role conversion of indoor and outdoor units as evaporators and condensers, which is conducive to improving system safety and reliability.

This system can realize normal heating and cooling, and can realize the non-interrupted heating of the heat pump to the building during the defrosting period, which ensures the stability of the system operation and indoor thermal comfort, and can promote a non-intermittent defrosting air source heat pump The application of the system in the field of residential buildings in our country provides theoretical support and technical reserves for the creation of efficient and comfortable building spaces, and contributes to the energy saving and emission reduction of buildings in cities and rural areas in our country, which has very important practical significance.

Finally, it should be noted that the solution of the present invention can also effectively avoid the impact of (1) the frost-melting water evaporation water vapor on other branch roads; (2) the impact of the defrosting water drop on other branch roads; 3) The influence of air flow on the defrosting speed of the defrosting pipeline; (4) The heat loss caused by the heat transfer between the defrosting branch and the non-defrosting branch. In addition, with the configuration of independent double outdoor heat exchangers, the fans can be controlled independently, which has the advantage of convenient regulation.

The embodiments of the present invention have been presented for purposes of illustration and description, but are not intended to be exhaustive or to limit the invention to the form disclosed. Many modifications and changes will be apparent to those of ordinary skill in the art. The embodiment was chosen and described in order to better explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention and design various embodiments with various modifications as are suited to the particular use.

Claims (5)

1. An air source heat pump system for non-intermittent heating during defrosting is characterized by comprising a compressor (1), a first reversing valve (2), a first heat exchanger (3), a one-way valve (5), a first electromagnetic valve (6), a second heat exchanger (9), a third electromagnetic valve (10) and a first throttling mechanism (11) which are sequentially arranged on a refrigerant loop; the first heat exchanger (3) is located indoors, a third heat exchanger (14) is arranged on the second heat exchanger (9) located outdoors in series, and a second reversing valve (8) is arranged between the first heat exchanger (3) and the second heat exchanger (9) as well as between the first heat exchanger and the third heat exchanger (14); a fourth electromagnetic valve (12) and a third throttling mechanism (13) are arranged on a pipeline where the third electromagnetic valve (10) and the first throttling mechanism (11) are located in parallel, a second electromagnetic valve (7) is arranged on a pipeline where the first electromagnetic valve (6), the second heat exchanger (9) and the third throttling mechanism (13) are located in parallel, a pipeline between the third electromagnetic valve (10) and the first throttling mechanism (11) is communicated with a pipeline between the second electromagnetic valve (7) and the third throttling mechanism (13), and a fifth electromagnetic valve (15) is arranged on the second reversing valve (8) in parallel.

2. A defrosting uninterrupted heating air source heat pump system according to claim 1, wherein a second throttling mechanism (4) is arranged on the one-way valve (5) in parallel.

3. A defrosting uninterrupted-heat-supply air-source heat pump system according to claim 1, further comprising a gas-liquid separator (16), wherein the gas-liquid separator (16) is arranged on a return air pipeline of the compressor (1).

4. A defrosting uninterrupted heating source air-source heat pump system according to any one of the claims 1 to 3, wherein the first reversing valve (2) and the second reversing valve (8) are both four-way reversing valves.

5. A defrosting uninterrupted heating air-source heat pump system according to claim 4, wherein the second heat exchanger (9) and the third heat exchanger (14) are both located outdoors.

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