CN106871479A - A kind of cold recovery formula varying capacity air source heat pump system - Google Patents

Abstract

A cooling capacity recovery type variable capacity air source heat pump system, involving a combined heating and cooling system operating alternately or simultaneously, the first subsystem and the second subsystem share a dual-channel variable capacity heat exchanger; the main body of the heat exchanger includes two Two independent refrigerant tube-side channels, the refrigerant in the two channels exchanges heat with the heat medium water in the shell-side channel at the same time; the shell-side channel establishes a water-medium heating cycle through the hot water circulation pipeline and the hot water circulation pump; The first subsystem and the second subsystem are connected to the two refrigerant tube channels through the control valve group to establish a dynamically controllable refrigerant circulation loop; the heat pump system controls the control valve group of the dual-channel variable-capacity heat exchanger. In the on-off state, the dual-channel variable-capacity mode is realized through the dual-channel variable-capacity heat exchanger, which can effectively use the heat exchange area of the shell-and-tube heat exchanger, so it can meet the requirements of stable output under heavy load conditions, and the overall operating efficiency of the unit is greatly improved. to achieve energy-efficient operation of the heat pump system.

Description

A cold recovery type variable capacity air source heat pump system

technical field

The invention relates to a combined heating and cooling system that operates alternately or simultaneously, and in particular to a heat pump combined cooling and heating system that mainly supplies heat while taking into account the supply of cold.

Background technique

The introduction of the slogan of intensive society construction promotes a higher degree of integration of the internal functions of the building itself, and the maximization of energy utilization has become a current topic. Today, commercial and commercial places have higher and higher requirements: the air side requires control of suitable temperature and humidity and air cleanliness; the water side water temperature requires suitable year-round. However, the traditional method of separate supply of cold and heat sources has obviously caused the misplacement of resources in different seasons, and at the same time, the initial investment cost of equipment has also been greatly increased. The chocolate processing technology shown in Figure 1, chocolate products are packaged into products after mixing and melting raw materials, fine grinding, refining, sieving, heat preservation, temperature adjustment, casting, cooling and hardening, which not only require a large amount of heat and cold supply , and each process link has strict requirements on temperature. Traditional temperature control generally supplies heat through electric heating, steam heating or combustion boilers, and processes that require different temperatures are often realized through different heating methods, which increases the operating cost of the enterprise and reduces work efficiency. At the same time, intelligent control cannot be realized, and a large amount of manpower is required. Therefore, it is necessary to transform the original energy-consuming production process and develop a combined heating and cooling system that can meet the requirements of food processing technology. Chinese invention patent "Multi-mode operation control method and control device for restaurant kitchen heat pump system" (invention patent number: 201410478406.0, authorized announcement number: CN104197584B) discloses a multi-mode operation control method and control device for restaurant kitchen heat pump system , relating to the control of the combined system of heating and cooling, and in particular to a control method and equipment for a heat pump integrated system suitable for hot water supply, cooling and dehumidification, and refrigeration and preservation in the back kitchen of a restaurant. The control device detects and compares the parameters of the operating mode Measured values and set values, control the multi-mode refrigerant cycle switching mechanism to change the refrigerant circulation path, control the hotel kitchen heat pump system to operate according to the preset operation mode, and realize automatic multi-mode operation.

On the other hand, the existing heat pump system with heat recovery function usually uses an independent condenser connected with an independent heat recovery unit to form a heating heat exchanger, which not only takes up a lot of space but also costs a lot. Chinese utility model patent "shell and tube heat exchanger and air conditioner" (utility model patent number: 201420417296.2, authorized announcement number: CN204084963U) discloses a shell and tube heat exchanger and an air conditioner including the shell and tube heat exchanger, the shell and tube The heat exchanger includes a condenser and a heat recovery device. One end of the condenser is provided with a cooling water inlet and a cooling water outlet, and the other end is sealed; one end of the heat recovery device is provided with a hot water inlet and a hot water outlet, and the other end is sealed with the condenser. Fixed connection at one end: By connecting the sealed ends of the condenser and the heat recovery unit fixedly, and connecting the heat recovery unit with the refrigerant channel of the condenser through the connecting pipe, the normal condensation function and heat dissipation of the shell-and-tube heat exchanger can be guaranteed. The recovery function can also make the structure of the shell and tube heat exchanger compact, save installation space and reduce costs. However, this prior art solution essentially only integrates two independent functional parts mechanically, and their respective functions are still independent of each other, which cannot improve the overall heat exchange efficiency of the heat exchanger.

Contents of the invention

The purpose of the present invention is to provide a cold recovery type variable capacity air source heat pump system, which is used to solve the problem of reducing equipment scale, saving equipment investment and operating costs, and improving heat exchange efficiency in the process of replacing traditional heating methods with heat pump combined cooling and heating systems and technical issues of unit energy efficiency.

The technical solution adopted by the present invention to solve the problems of the technologies described above is:

A cold recovery type variable capacity air source heat pump system, including a first subsystem composed of a first compressor and a cold recovery heat exchanger, a second subsystem composed of a second compressor and a finned heat exchanger, It is characterized in that;

The first subsystem and the second subsystem use a dual-channel variable-capacity heat exchanger as a water-cooled condenser; the dual-channel variable-capacity heat exchanger includes a heat exchanger body and a set of solenoid valves A control valve group composed of a one-way valve; the main body of the heat exchanger includes two mutually independent refrigerant tube-side channels placed in the same shell-side channel, and the refrigerant in the two refrigerant tube-side channels is simultaneously connected to the shell-side channel The water is used for heat exchange; the shell-side channel of the heat exchanger main body establishes a water-medium heating cycle through the hot water circulation pipeline and the hot water circulation pump;

The first subsystem and the second subsystem are connected to the two refrigerant tube channels through the control valve group to establish a dynamically controllable refrigerant circulation loop; the heat pump system is controlled by controlling the dual-channel variable-capacity heat exchanger The switch state of the valve group realizes the dynamic multi-mode operation of the heat pump system.

A preferred technical solution of the cold recovery type variable capacity air source heat pump system of the present invention is characterized in that the double-channel variable capacity heat exchanger includes a shell and tube heat exchanger as the main body of the heat exchanger and The control valve group connected to the refrigerant tube channel of the shell-and-tube heat exchanger; the main body of the heat exchanger is provided with two mutually independent first refrigerant channels and second refrigerant channels, and the two refrigerant tubes The side channel is placed in a shared shell side channel; the control valve group includes three solenoid valves and two check valves connected to the refrigerant tube side channel; the solenoid valve includes a valve connected to the first refrigerant tube The first solenoid valve at the outlet of the passage, the second solenoid valve connected between the outlet of the first refrigerant passage and the inlet of the second refrigerant passage, and the third solenoid valve connected at the outlet of the second refrigerant passage; the single The directional valve includes a first one-way valve connected to the inlet of the second refrigerant passage, and a second one-way valve connected in parallel between the outlet of the second refrigerant passage and the outlet of the first solenoid valve; the exhaust of the first compressor The port is connected to the inlet of the first refrigerant passage through the first four-way valve; after the outlet of the first solenoid valve is connected in parallel with the outlet of the second one-way valve, it is connected to the refrigerant of the cold recovery heat exchanger through the first expansion valve. agent channel, and then connected to the inlet of the first compressor through the first four-way valve; the exhaust port of the second compressor is connected to the inlet of the first one-way valve through the second four-way valve; the third solenoid valve The outlet is connected to the refrigerant channel of the fin heat exchanger through the second expansion valve, and then connected to the air inlet of the second compressor through the second four-way valve.

A preferred technical solution of the double-channel variable-capacity heat exchanger of the present invention is characterized in that the main body of the heat exchanger adopts a vertical structure in which the shell-side channel communicates up and down, and the first refrigerant channel is placed in the shell-side channel The upper part of the second refrigerant channel is placed at the lower part of the shell-side channel; the high-temperature sensible heat of the refrigerant is transferred to the water in the upper part of the shell-side channel in the first refrigerant channel, forming a high-temperature sensible heat heat exchange zone; the condensation of the refrigerant The latent heat is transferred to the water in the lower part of the shell-side channel in the second refrigerant channel, forming a condensation latent heat heat exchange area.

A better technical solution of the cold recovery type variable capacity air source heat pump system of the present invention is characterized in that a first liquid reservoir is provided on the connecting pipeline between the first refrigerant passage and the first expansion valve, A second liquid accumulator is provided on the connecting pipeline between the second refrigerant channel and the second expansion valve.

An improved technical solution of the cold recovery type variable capacity air source heat pump system of the present invention is characterized in that the dynamic multi-mode operation includes the following four operation modes:

(1) Cooling and heating balance mode of the first subsystem: the first compressor is started, the second compressor is stopped, the first solenoid valve is opened, and the second solenoid valve is closed. The refrigerant circulation path in this mode is as follows:

The first compressor - the first four-way valve - the first refrigerant passage - the first solenoid valve - the first liquid receiver - the first expansion valve - the cooling recovery heat exchanger - the first four-way valve - the first gas-liquid Separator - first compressor;

(2) The air source hot water mode of the second subsystem: the first compressor is stopped, the second compressor is started, the second solenoid valve is closed, and the third solenoid valve is opened. The refrigerant circulation path in this mode is as follows:

The second compressor - the second four-way valve - the first one-way valve - the second refrigerant passage - the third solenoid valve - the second liquid receiver - the second expansion valve - finned heat exchanger - the second four-way valve - the second gas-liquid separator - the second compressor;

(3) Dual system constant volume cold and hot water mode: the first compressor and the second compressor start at the same time, the first solenoid valve is opened, the second solenoid valve is closed, the third solenoid valve is opened, and the refrigerant cycle of the first subsystem The path is as follows:

The first compressor - the first four-way valve - the first refrigerant passage - the first solenoid valve - the first liquid receiver - the first expansion valve - the cooling recovery heat exchanger - the first four-way valve - the first gas-liquid Separator - first compressor;

The refrigerant circulation path of the second subsystem is as follows:

The second compressor - the second four-way valve - the first one-way valve - the second refrigerant passage - the third solenoid valve - the second liquid receiver - the second expansion valve - finned heat exchanger - the second four-way valve - the second gas-liquid separator - the second compressor;

(4) Two-channel variable capacity operation mode: the first compressor is started, the second compressor is stopped, the first solenoid valve is closed, the second solenoid valve is opened, and the third solenoid valve is closed. The refrigerant circulation path in this mode is as follows:

The first compressor - the first four-way valve - the first refrigerant passage - the second solenoid valve - the second refrigerant passage - the second one-way valve - the first liquid receiver - the first expansion valve - cooling recovery and heat exchange Device - the first four-way valve - the first gas-liquid separator - the first compressor.

A further improved technical solution of the cooling capacity recovery type variable capacity air source heat pump system of the present invention is characterized in that the air source heat pump system changes the heat exchange area of the finned heat exchanger according to the cooling capacity recovered by refrigeration. Reduce the overall system size of the heat pump system while ensuring the heating capacity of the unit:

The heat exchange area S of the finned heat exchanger varies from 0 to W ₂ /q,

The heat exchange area S ₁ of the cold recovery heat exchanger varies from 0 to (W ₁ -W ₂ )/q ₁ ,

Among them, the heating capacity of the unit Q ₁ =W ₁ +P _i , kw; W ₁ is the cooling capacity of the evaporator side during the heating operation of the system, kw; P _i is the input power of the heating operation of the system, kw; W ₂ is the cooling recovery Cooling capacity, kw; S=W ₂ /q is the heat transfer area of the finned heat exchanger, m ² ; q is the cooling capacity per unit heat transfer area of the evaporation side under heating conditions, kw/m ² ; S ₁ = (W ₁ -W ₂ )/q ₁ is the heat transfer area of the cold recovery heat exchanger, m ² ; q ₁ is the cooling capacity per unit heat transfer area of the cold recovery heat exchanger, kw/m ² .

The beneficial effects of the present invention are:

1. The cold recovery type variable capacity air source heat pump system of the present invention realizes the dual channel variable capacity mode through the dual channel variable capacity heat exchanger, which can effectively utilize the heat exchange area of the shell and tube heat exchanger, thus meeting the needs of large To meet the requirements of stable output under load conditions, the overall operating efficiency of the unit is greatly improved, thereby realizing the energy-efficient operation of the heat pump system.

2. The cold recovery type variable capacity air source heat pump system of the present invention uses the dual-channel variable capacity heat exchanger and the cold recovery heat exchanger operating in the variable capacity mode to realize part of the cold recovery, which can greatly improve the cooling capacity of the subsystem. The subcooling degree of the agent, thereby increasing the cooling capacity of the system.

3. The cooling capacity recovery type variable capacity air source heat pump system of the present invention realizes coupled operation through two sets of refrigeration systems sharing a set of water-cooled condensers, and uses the cooling capacity recovery heat exchanger to reduce the size of the finned evaporator, thereby achieving The purpose of reducing the size of the system is to enable the combined cooling and heating system to operate stably with low consumption under different cooling and heating loads, so as to achieve the purpose of high-efficiency and energy-saving operation.

Description of drawings

Fig. 1 is a chocolate processing flow chart;

Fig. 2 is a system schematic diagram of the cold recovery type variable capacity air source heat pump system of the present invention;

Fig. 3 is a schematic diagram of the assembly structure of the cold recovery type variable capacity air source heat pump system of the present invention;

Fig. 4 is a schematic structural view of a double-channel variable-capacity heat exchanger of the present invention;

Fig. 5 is a schematic diagram of the operation mode of the cold recovery type variable capacity air source heat pump system of the present invention.

The reference signs of the components in the above figure: 1-the first subsystem, 10-the first compressor, 11-the first four-way valve, 12-the first expansion valve, 13-cold recovery heat exchanger, 14- Cold water circulation pipeline, 15-the first gas-liquid separator, 16-the first temperature sensing bulb, 17-the first liquid reservoir, 18-the first defrosting one-way solenoid valve, 2-the second subsystem, 20- The second compressor, 21-the second four-way valve, 22-the second expansion valve, 23-fin heat exchanger, 24-fan, 25-the second gas-liquid separator, 26-the second temperature sensor, 27-Second liquid receiver, 28-Second defrosting one-way solenoid valve, 3-Double-channel variable capacity heat exchanger, 30-Heat exchanger main body, 31-First refrigerant channel, 32-Second refrigeration agent channel, 33-first solenoid valve, 34-second solenoid valve, 35-third solenoid valve, 36-first one-way valve, 37-second one-way valve, 38-hot water circulation pipeline, 39- Hot water circulation pump.

detailed description

In order to better understand the above technical solutions of the present invention, a further detailed description will be given below in conjunction with the drawings and embodiments. Fig. 2 and Fig. 3 are an embodiment of the cooling capacity recovery variable capacity air source heat pump system of the present invention, including the first subsystem 1 composed of the first compressor 10 and the cooling capacity recovery heat exchanger 13, and the second compressor 20 and the second subsystem 2 composed of finned heat exchanger 23, as shown in Figure 2, the first subsystem 1 and the second subsystem 2 share a dual-channel variable capacity heat exchanger 3 as Water-cooled condenser; the dual-channel variable-capacity heat exchanger 3 includes a heat exchanger main body 30 and a set of control valve groups composed of solenoid valves and check valves; the heat exchanger main body 30 includes channels placed on the same shell side There are two mutually independent refrigerant tube-side channels, and the refrigerant in the two refrigerant tube-side channels exchanges heat with the water in the shell-side channel at the same time; the shell-side channel of the heat exchanger main body 30 passes through the hot water circulation pipeline 38 and hot water circulation pump 39 to establish a water-medium heating cycle; the first subsystem 1 and the second subsystem 2 are connected to the two refrigerant tube channels through the control valve group to establish a dynamically controllable refrigerant cycle Circuit: The heat pump system realizes the dynamic multi-mode operation of the heat pump system by controlling the switch state of the control valve group of the dual-channel variable capacity heat exchanger 3 . Taking a chocolate processing line as an example, the production process of 1T of raw materials from processing to final packaging into products requires a stable demand for 100KW of heat and 50KW of cooling. In this embodiment, the first sub-system 1 adopts the sleeve-type evaporator as the cooling capacity recovery heat exchanger 13, and recovers part of the cooling capacity for the cooling capacity in the process of molding, cooling hardening and packaging of chocolate processing. Supply; the second subsystem 2 uses the finned heat exchanger 23 to absorb heat from the air source, and increases the overall heating capacity of the heat pump system according to the difference in cold and heat demand.

In the embodiment shown in FIG. 4, the dual-channel variable-capacity heat exchanger 3 includes a shell-and-tube heat exchanger as the heat exchanger body 30 and a refrigerant tube-side channel connected to the shell-and-tube heat exchanger. control valve group; the heat exchanger main body 30 is provided with two mutually independent first refrigerant passages 31 and second refrigerant passages 32, and the two refrigerant pipe-side passages 31 and 32 are placed in a common In the shell-side passage; the control valve group includes three solenoid valves and two check valves connected to the refrigerant pipe-side passage; the solenoid valve includes a first solenoid valve connected to the outlet of the first refrigerant passage 31 valve 33, the second solenoid valve 34 connected between the outlet of the first refrigerant passage 31 and the inlet of the second refrigerant passage 32, and the third solenoid valve 35 connected at the outlet of the second refrigerant passage 32; the single The one-way valve includes a first one-way valve 36 connected to the inlet of the second refrigerant passage 32, and a second one-way valve 37 connected in parallel between the outlet of the second refrigerant passage 32 and the outlet of the first electromagnetic valve 33; The exhaust port of the compressor 10 is connected to the inlet of the first refrigerant channel 31 through the first four-way valve 11; after the outlet of the first solenoid valve 33 and the outlet of the second one-way valve 37 are connected in parallel, they pass through the first expansion valve. 12 is connected to the refrigerant channel of the cold recovery heat exchanger 13, and then connected to the intake port of the first compressor 10 through the first four-way valve 11; the exhaust port of the second compressor 20 is passed through the second four-way valve 21 is connected to the inlet of the first one-way valve 36; the outlet of the third solenoid valve 35 is connected to the refrigerant channel of the fin heat exchanger 23 through the second expansion valve 22, and then connected to the first four-way valve 21 through the second expansion valve 21. The air inlet of the second compressor 20.

According to an embodiment of the double-channel variable-capacity heat exchanger of the present invention, the heat exchanger main body 30 adopts a vertical structure in which the shell-side channel communicates up and down, and the first refrigerant channel 31 is placed on the upper part of the shell-side channel. The second refrigerant channel 32 is placed in the lower part of the shell-side channel; the high-temperature sensible heat of the refrigerant is transferred to the water in the upper part of the shell-side channel in the first refrigerant channel 31, forming a high-temperature sensible heat heat exchange zone; the latent heat of condensation of the refrigerant The water transferred to the lower part of the shell-side channel in the second refrigerant channel 32 forms a condensation latent heat heat exchange area.

According to the embodiment of the cold recovery type variable capacity air source heat pump system of the present invention shown in FIG. , the second liquid accumulator 27 is provided on the connecting pipeline between the second refrigerant channel 32 and the second expansion valve 22 .

According to the embodiment of the cold recovery type variable capacity air source heat pump system of the present invention shown in Fig. 5, the dynamic multi-mode operation includes the following four operation modes:

(1) The cooling and heating balance mode of the first subsystem: the first compressor 10 is started, the second compressor 20 is stopped, the first solenoid valve 33 is opened, and the second solenoid valve 34 is closed. The refrigerant circulation path in this mode is as follows:

First compressor 10-first four-way valve 11-first refrigerant channel 31-first solenoid valve 33-first liquid receiver 17-first expansion valve 12-cold recovery heat exchanger 13-first four Through valve 11-the first gas-liquid separator 15-the first compressor 10;

In this mode, the refrigerant in the first refrigerant channel 31 exchanges heat with the water in the shell-side channel, and transfers the heat energy recovered by the cold recovery heat exchanger 13 in the process of producing cold water by the first subsystem 1 to the heat exchanger. The hot water produced in the shell side channel of the heater main body 30.

(2) The air source hot water mode of the second subsystem: the first compressor 10 is stopped, the second compressor 20 is started, the second solenoid valve 34 is closed, and the third solenoid valve 35 is opened. The refrigerant circulation path in this mode is as follows:

The second compressor 20-the second four-way valve 21-the first one-way valve 36-the second refrigerant channel 32-the third solenoid valve 35-the second liquid reservoir 27-the second expansion valve 22-fin type exchange Heater 23-second four-way valve 21-second gas-liquid separator 25-second compressor 20;

In this mode, the refrigerant in the second refrigerant channel 32 exchanges heat with the water in the shell-side channel, and transfers the heat energy absorbed by the finned heat exchanger 23 of the second subsystem 2 from the air source to the heat exchange The hot water produced in the shell side channel of the device main body 30.

(3) Dual-system constant-capacity cold and hot water mode: the first compressor 10 and the second compressor 20 are started simultaneously, the first solenoid valve 33 is opened, the second solenoid valve 34 is closed, the third solenoid valve 35 is opened, and the first The refrigerant circulation path of system 1 is as follows:

First compressor 10-first four-way valve 11-first refrigerant channel 31-first solenoid valve 33-first liquid receiver 17-first expansion valve 12-cold recovery heat exchanger 13-first four Through valve 11-the first gas-liquid separator 15-the first compressor 10;

The refrigerant circulation path of the second subsystem 2 is as follows:

The second compressor 20-the second four-way valve 21-the first one-way valve 36-the second refrigerant channel 32-the third solenoid valve 35-the second liquid reservoir 27-the second expansion valve 22-fin type exchange Heater 23-second four-way valve 21-second gas-liquid separator 25-second compressor 20;

In the dual-system constant-volume cold and hot water mode, the refrigerant in the first refrigerant channel 31 exchanges heat with the water in the shell-side channel, and the cold energy recovery heat exchanger 13 in the cold water production process of the first subsystem 1 The recovered heat energy is transferred to the hot water produced in the shell-side channel of the heat exchanger main body 30; at the same time, the refrigerant in the second refrigerant channel 32 exchanges heat with the water in the shell-side channel, and the second subsystem 2 The heat energy absorbed by the finned heat exchanger 23 from the air source is transferred to the hot water produced in the shell-side channel of the heat exchanger main body 30 .

(4) Two-channel variable capacity mode: the first compressor 10 is started, the second compressor 20 is stopped, the first solenoid valve 33 is closed, the second solenoid valve 34 is opened, the third solenoid valve 35 is closed, and the refrigerant cycle in this mode The path is as follows:

First compressor 10-first four-way valve 11-first refrigerant passage 31-second solenoid valve 34-second refrigerant passage 32-second one-way valve 37-first accumulator 17-first expansion Valve 12—cold recovery heat exchanger 13—first four-way valve 11—first gas-liquid separator 15—first compressor 10.

In the dual-channel variable capacity mode, the high-temperature and high-pressure refrigerant gas discharged from the exhaust port of the first compressor 10 of the cooling recovery type variable capacity air source heat pump system of the present invention enters the dual-channel variable capacity through the first four-way valve 11. In the capacity heat exchanger 3, after flowing through the first refrigerant channel 31 for the first stage of heat exchange, the refrigerant gas-liquid mixture is formed and returned to the dual-channel variable capacity heat exchanger 3 through the second solenoid valve 34. The second refrigerant channel 32 fully exchanges heat with the water side of the heat exchanger main body 30 again, condenses into a refrigerant liquid at high pressure and normal temperature, flows through the second check valve 37 and then through the throttling effect of the first expansion valve 12, It becomes a low-pressure refrigerant liquid and enters the jacketed evaporator as the cold recovery heat exchanger 13, absorbs heat and evaporates into a low-pressure refrigerant gas, enters the first gas-liquid separator 15 through the first four-way valve 11, and finally enters the second gas-liquid separator 15. A compressor 10 inlet, forming a refrigerant circulation path for dual-channel variable capacity mode operation; in this mode, the refrigerant passes through the first refrigerant channel 31 and the second refrigerant channel 32, and the water in the shell-side channel Two heat exchanges are performed, and the heat recovered by the cold recovery heat exchanger 13 in the cold water production process of the first subsystem 1 is transferred to the hot water produced in the shell-side channel of the heat exchanger main body 30 .

In the dual-channel variable capacity mode, the high-temperature and high-pressure refrigerant gas discharged from the exhaust port of the first compressor 10 of the cooling recovery type variable capacity air source heat pump system of the present invention enters the dual-channel variable capacity through the first four-way valve 11. In the capacity heat exchanger 3, after flowing through the first refrigerant channel 31 for the first stage of heat exchange, the refrigerant gas-liquid mixture is formed and returned to the dual-channel variable capacity heat exchanger 3 through the second solenoid valve 34. The second refrigerant channel 32 fully exchanges heat with the water side of the heat exchanger main body 30 again, condenses into a refrigerant liquid at high pressure and normal temperature, flows through the second check valve 37 and then through the throttling effect of the first expansion valve 12, It becomes a low-pressure refrigerant liquid and enters the jacketed evaporator as the cold recovery heat exchanger 13, absorbs heat and evaporates into a low-pressure refrigerant gas, enters the first gas-liquid separator 15 through the first four-way valve 11, and finally enters the second gas-liquid separator 15. An air inlet of the compressor 10 forms a refrigerant circulation path operated in a dual-channel variable capacity mode.

The cooling capacity recovery type variable capacity air source heat pump system of the present invention can greatly increase the subcooling degree of the refrigerant in the first subsystem 1 by using the dual-channel variable capacity heat exchanger 3 operating in the variable capacity mode, thereby improving the efficiency of the system. cooling capacity. When the second subsystem 2 is shut down, the dual-channel variable capacity mode can effectively use the heat exchange area of the shell-and-tube heat exchanger, so it can meet the requirements of stable output under heavy load conditions, and the overall operating efficiency of the unit is greatly improved, thereby realizing heat pump Energy-efficient operation of the system.

According to an embodiment of the cooling capacity recovery variable capacity air source heat pump system of the present invention, the air source heat pump system changes the heat exchange area of the fin heat exchanger according to the cooling capacity recovered by refrigeration, while ensuring the heating capacity of the unit Reduce the overall system size of the heat pump system:

The heat exchange area S of the finned heat exchanger 23 varies from 0 to W ₂ /q,

The heat exchange area S ₁ of the cold recovery heat exchanger 13 varies from 0 to (W ₁ -W ₂ )/q ₁ ,

Among them, the heating capacity of the unit Q ₁ =W ₁ +P _i , kw; W ₁ is the cooling capacity of the evaporator side during the heating operation of the system, kw; P _i is the input power of the heating operation of the system, kw; W ₂ is the cooling recovery Cooling capacity, kw; S=W ₂ /q is the heat transfer area of the finned heat exchanger 23, m ² ; q is the cooling capacity per unit heat transfer area of the evaporation side under heating conditions, kw/m ² ; S ₁ =(W ₁ −W ₂ )/q ₁ is the heat exchange area of the cold recovery heat exchanger 13, m ² ; q ₁ is the cooling capacity per unit heat exchange area of the cold recovery heat exchanger 13, kw/m ² .

Those of ordinary skill in the technical field should recognize that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not used as limitations to the present invention. All changes and modifications will fall within the protection scope of the claims of the present invention.

Claims (6)

1. A cooling capacity recovery variable capacity air source heat pump system, including the first sub-system composed of the first compressor and the cooling capacity recovery heat exchanger, the second sub-system composed of the second compressor and the finned heat exchanger system, characterized in that: The first subsystem and the second subsystem use a dual-channel variable-capacity heat exchanger as a water-cooled condenser; the dual-channel variable-capacity heat exchanger includes a heat exchanger body and a set of solenoid valves A control valve group composed of a one-way valve; the main body of the heat exchanger includes two mutually independent refrigerant tube-side channels placed in the same shell-side channel, and the refrigerant in the two refrigerant tube-side channels is simultaneously connected to the shell-side channel The water is used for heat exchange; the shell-side channel of the heat exchanger main body establishes a water-medium heating cycle through the hot water circulation pipeline and the hot water circulation pump; The first subsystem and the second subsystem are connected to the two refrigerant tube channels through the control valve group to establish a dynamically controllable refrigerant circulation loop; the heat pump system is controlled by controlling the dual-channel variable-capacity heat exchanger The switch state of the valve group realizes the dynamic multi-mode operation of the heat pump system. 2. The cold recovery type variable capacity air source heat pump system according to claim 1, characterized in that the double-channel variable capacity heat exchanger comprises a shell and tube heat exchanger as the main body of the heat exchanger and connected to The control valve group of the refrigerant tube-side channel of the shell-and-tube heat exchanger; the main body of the heat exchanger is provided with two mutually independent first refrigerant channels and second refrigerant channels, and the two refrigerant tube-side channels Placed in a common shell-side channel; the control valve group includes three solenoid valves and two check valves connected to the refrigerant tube-side channel; the solenoid valve includes a valve connected to the outlet of the first refrigerant channel The first solenoid valve, the second solenoid valve connected between the outlet of the first refrigerant passage and the inlet of the second refrigerant passage, and the third solenoid valve connected at the outlet of the second refrigerant passage; the one-way valve It includes a first one-way valve connected to the inlet of the second refrigerant passage, and a second one-way valve connected in parallel between the outlet of the second refrigerant passage and the outlet of the first electromagnetic valve; the exhaust port of the first compressor passes through The first four-way valve is connected to the inlet of the first refrigerant passage; after the outlet of the first solenoid valve and the outlet of the second one-way valve are connected in parallel, they are connected to the refrigerant passage of the cold recovery heat exchanger through the first expansion valve , and then connected to the intake port of the first compressor through the first four-way valve; the exhaust port of the second compressor is connected to the inlet of the first one-way valve through the second four-way valve; the outlet of the third solenoid valve is connected to the The second expansion valve is connected to the refrigerant channel of the finned heat exchanger, and then connected to the air inlet of the second compressor through the second four-way valve. 3. The cold recovery type variable capacity air source heat pump system according to claim 2, characterized in that a first liquid accumulator is provided on the connecting pipeline between the first refrigerant passage and the first expansion valve, A second liquid accumulator is arranged on the connecting pipeline between the second refrigerant channel and the second expansion valve. 4. The cold recovery type variable capacity air source heat pump system according to claim 2, characterized in that the main body of the heat exchanger adopts a vertical structure in which the shell side channel is connected up and down, and the first refrigerant channel is placed on the shell side In the upper part of the channel, the second refrigerant channel is placed in the lower part of the shell-side channel; the high-temperature sensible heat of the refrigerant is transferred to the water in the upper part of the shell-side channel in the first refrigerant channel, forming a high-temperature sensible heat exchange area; The condensation latent heat is transferred to the water in the lower part of the shell side passage in the second refrigerant passage, forming a condensation latent heat heat exchange area. 5. The cold recovery type variable capacity air source heat pump system according to claim 1, characterized in that the dynamic multi-mode operation includes the following four operation modes: (1) Cooling and heating balance mode of the first subsystem: the first compressor is started, the second compressor is stopped, the first solenoid valve is opened, and the second solenoid valve is closed. The refrigerant circulation path in this mode is as follows: The first compressor - the first four-way valve - the first refrigerant passage - the first solenoid valve - the first liquid receiver - the first expansion valve - the cooling recovery heat exchanger - the first four-way valve - the first gas-liquid Separator - first compressor; (2) The air source hot water mode of the second subsystem: the first compressor is stopped, the second compressor is started, the second solenoid valve is closed, and the third solenoid valve is opened. The refrigerant circulation path in this mode is as follows: The second compressor - the second four-way valve - the first one-way valve - the second refrigerant passage - the third solenoid valve - the second liquid receiver - the second expansion valve - finned heat exchanger - the second four-way valve - the second gas-liquid separator - the second compressor; (3) Dual system constant volume cold and hot water mode: the first compressor and the second compressor start at the same time, the first solenoid valve is opened, the second solenoid valve is closed, the third solenoid valve is opened, and the refrigerant cycle of the first subsystem The path is as follows: The first compressor - the first four-way valve - the first refrigerant passage - the first solenoid valve - the first liquid receiver - the first expansion valve - the cooling recovery heat exchanger - the first four-way valve - the first gas-liquid Separator - first compressor; The refrigerant circulation path of the second subsystem is as follows: The second compressor - the second four-way valve - the first one-way valve - the second refrigerant passage - the third solenoid valve - the second liquid receiver - the second expansion valve - finned heat exchanger - the second four-way valve - the second gas-liquid separator - the second compressor; (4) Two-channel variable capacity operation mode: the first compressor is started, the second compressor is stopped, the first solenoid valve is closed, the second solenoid valve is opened, and the third solenoid valve is closed. The refrigerant circulation path in this mode is as follows: The first compressor - the first four-way valve - the first refrigerant passage - the second solenoid valve - the second refrigerant passage - the second one-way valve - the first liquid receiver - the first expansion valve - cooling recovery and heat exchange Device - the first four-way valve - the first gas-liquid separator - the first compressor. 6. The cold recovery type variable capacity air source heat pump system according to claim 1, characterized in that the air source heat pump system changes the heat exchange area of the fin heat exchanger according to the cooling capacity recovered by refrigeration, ensuring that the unit Reduce the overall system size of the heat pump system while heating: The heat exchange area S of the finned heat exchanger varies from 0 to W ₂ /q, The heat exchange area S ₁ of the cold recovery heat exchanger varies from 0 to (W ₁ -W ₂ )/q ₁ , Among them, the heating capacity of the unit Q ₁ =W ₁ +P _i , kw; W ₁ is the cooling capacity of the evaporator side during the heating operation of the system, kw; P _i is the input power of the heating operation of the system, kw; W ₂ is the cooling recovery Cooling capacity, kw; S=W ₂ /q is the heat transfer area of the finned heat exchanger, m ² ; q is the cooling capacity per unit heat transfer area of the evaporation side under heating conditions, kw/m ² ; S ₁ = (W ₁ -W ₂ )/q ₁ is the heat transfer area of the cold recovery heat exchanger, m ² ; q ₁ is the cooling capacity per unit heat transfer area of the cold recovery heat exchanger, kw/m ² .