CN107062670B - Double-channel variable-capacity heat exchanger - Google Patents

Abstract

A double-channel variable-capacity heat exchanger relates to a heating and refrigerating combined system or a component, a device or a component of a heat pump system, in particular to a heat exchanger for a heat pump type combined cooling and heating system; the heat exchanger main body comprises two mutually independent refrigerant tube pass channels, and refrigerants in the two channels exchange heat with heat medium water in the shell pass channel at the same time; the shell pass channel establishes a water medium heat supply circulation through a hot water circulation pipeline and a hot water circulation pump; the first subsystem and the second subsystem are connected to two refrigerant tube pass channels through a control valve group to establish a dynamically controllable refrigerant circulation loop; the heat pump system realizes a double-channel variable volume mode through controlling the on-off state of a control valve group of the double-channel variable volume heat exchanger and the double-channel variable volume heat exchanger, and can effectively utilize the heat exchange area of the shell and tube heat exchanger, thereby meeting the requirement of stable output under a heavy load working condition, greatly improving the overall operation efficiency of the unit and further realizing the high-energy-efficiency operation of the heat pump system.

Description

A dual-channel variable-capacity heat exchanger

technical field

The present invention relates to a combined heating and cooling system or a component, device or component of a heat pump system, in particular to a heat exchanger for a heat pump combined cooling and heating system.

Background technique

The introduction of the slogan of intensive society construction has promoted a higher degree of functional integration in the building itself, and maximized energy utilization has become a current issue. Today, the requirements of commercial and commercial places are getting higher and higher: the air side needs to control the appropriate temperature, humidity and air cleanliness; the water side water temperature is required to be suitable throughout the year. The traditional method of supplying cold and heat sources separately has obviously caused misplacement of resources in different seasons, and at the same time, the initial investment cost of equipment has also greatly increased. The chocolate processing process shown in Figure 1, the chocolate products are mixed and melted, finely ground, refined, sieved, heat preservation, temperature adjusted, moulded and cooled and hardened, and finally packaged into products, which not only requires 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 requiring 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 achieved, requiring a lot of human input. 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. The Chinese invention patent "Multi-mode operation control method and control device of restaurant back kitchen heat pump system" (invention patent number: 201410478406.0, authorized announcement number: CN104197584B) discloses a restaurant back kitchen heat pump system multi-mode operation control method and control device. , involving the control of a combined heating and cooling system, in particular a control method and equipment for a heat pump integrated system for hot water supply, cooling and dehumidification, and refrigeration and preservation suitable for restaurant kitchens. The measured value and the set value, control the multi-mode refrigerant circulation circuit switching mechanism to change the refrigerant circulation path, and control the restaurant rear kitchen heat pump system to operate according to the preset operation mode to realize automatic multi-mode operation.

On the other hand, the existing heat pump system with heat recovery function usually adopts an independent condenser and an independent heat recovery device to form a heating heat exchanger, which not only occupies a large space but also has a high cost. Chinese utility model patent "Shell and Tube Heat Exchanger and Air Conditioner" (Utility Model Patent No.: 201420417296.2, Authorized Announcement No.: CN204084963U) discloses a shell and tube heat exchanger and an air conditioner including the shell and tube heat exchanger. 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 fixing the respective sealed ends of the condenser and the heat recovery device, and connecting the heat recovery device and the refrigerant channel of the condenser through the connecting pipe, it can ensure the normal condensing function and heat recovery of the shell and tube heat exchanger. The recovery function can also make the shell and tube heat exchanger compact, save installation space and reduce costs. However, the prior art solution essentially only mechanically designs two independent functional components into one, and their respective functions are still independent of each other, which cannot improve the overall heat exchange efficiency of the heat exchanger.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a dual-channel variable-capacity heat exchanger for a heat pump combined cooling and heating system, which is used to reduce equipment size and save equipment investment in the process of replacing traditional heating methods with a heat pump combined cooling and heating system. and operating costs, and improve the technical issues of heat exchange efficiency and unit energy efficiency.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is:

A dual-channel variable-capacity heat exchanger is used for an air source heat pump hot water system with cold energy recovery, the air source heat pump hot water system includes a first compressor and a cold energy recovery heat exchanger. The subsystem, the second subsystem composed of the second compressor and the finned heat exchanger, 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 a control valve group connected to the refrigerant tube-side channel of the shell-and-tube heat exchanger;

The heat exchanger main body is provided with two mutually independent first refrigerant passages and second refrigerant passages, and the two refrigerant tube side passages are placed in a common shell side passage; The two subsystems are connected to the two refrigerant tube-side passages through the control valve group to establish a dynamically controllable refrigerant circulation loop;

The refrigerant in the two refrigerant tube-side channels exchanges heat with the water in the shell-side channels at the same time; the shell-side channel of the heat exchanger main body establishes a water-medium heat supply cycle through the hot water circulation pipeline and the hot water circulation pump;

The control valve group includes three solenoid valves and two one-way valves connected to the refrigerant tube-side passage; the solenoid valve includes a first solenoid valve connected to the outlet of the first refrigerant passage and connected to the first solenoid valve. a second solenoid valve between the outlet of the refrigerant passage and the inlet of the second refrigerant passage, and a third solenoid valve connected to the outlet of the second refrigerant passage; the one-way valve includes a solenoid valve connected to the inlet of the second refrigerant passage a first check valve, and a second check valve connected in parallel between the outlet of the second refrigerant passage and the outlet of the first solenoid valve;

The refrigerant discharge line of the first compressor 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 cold energy recovery exchanger through the first expansion valve. The refrigerant passage of the heat exchanger; the refrigerant discharge line of the second compressor is connected to the inlet of the first one-way valve; the outlet of the third solenoid valve is connected to the refrigerant of the fin heat exchanger through the second expansion valve aisle;

The air source heat pump hot water system realizes the dynamic multi-mode operation of the dual-channel variable-capacity heat exchanger by changing the switch state of the control valve group.

A preferred technical solution of the dual-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 channels are connected up and down, and the first refrigerant channel is placed on the shell-side 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 heat exchange area; The latent heat of condensation is transferred to the water in the lower part of the shell-side channel in the second refrigerant channel to form a latent heat of condensation heat exchange area.

A better technical solution of the dual-channel variable-capacity heat exchanger of the present invention is characterized in that the dynamic multi-mode operation includes the following four operation modes:

(1) Cold and heat 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. In this mode, the high-temperature and high-pressure refrigerant discharged from the first compressor circulates Enter the first refrigerant passage, and then enter the cold energy recovery heat exchanger through the first solenoid valve and the first expansion valve to establish the first subsystem refrigerant circulation circuit; the refrigerant in the first refrigerant passage and the shell side passage The heat exchange is carried out with the water obtained by the first subsystem, and the heat energy recovered by the cold energy recovery heat exchanger in the process of producing cold water by the first subsystem is transferred to the hot water produced in the shell-side channel of the main body of the heat exchanger;

(2) 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. In this mode, the high-temperature and high-pressure refrigerant discharged from the second compressor Enter the second refrigerant passage through the first one-way valve, and then enter the finned heat exchanger through the third solenoid valve and the second expansion valve to establish the refrigerant circulation circuit of the second subsystem; the refrigeration in the second refrigerant passage The agent exchanges heat with the water in the shell-side channel, and transfers the heat energy absorbed by the fin heat exchanger of the second subsystem from the air source to the hot water produced in the shell-side channel of the main body of the heat exchanger;

(3) Dual-system constant volume hot and cold water mode: the first compressor and the second compressor are started at the same time, the first solenoid valve is opened, the second solenoid valve is closed, and the third solenoid valve is opened; in this mode, the first compressor discharges The high temperature and high pressure refrigerant circulates into the first refrigerant passage, and then enters the cold energy recovery heat exchanger through the first solenoid valve and the first expansion valve to establish the first subsystem refrigerant circulation circuit; the high temperature and high pressure discharged from the second compressor The refrigerant enters the second refrigerant passage through the first one-way valve, and then enters the finned heat exchanger through the third solenoid valve and the second expansion valve to establish the refrigerant circulation circuit of the second subsystem; The refrigerant in the heat exchanger exchanges heat with the water in the shell-side channel, and transfers the heat energy recovered by the cold-capacity recovery heat exchanger during the cold-water production process of the first subsystem to the hot water produced in the shell-side channel of the main body of the heat exchanger; At the same time, the refrigerant in the second refrigerant channel exchanges heat with the water in the shell-side channel, and transfers the heat energy absorbed by the fin heat exchanger of the second subsystem from the air source to the shell-side channel of the main body of the heat exchanger. hot water from the

(4) Dual-channel variable capacity operation mode: the first compressor starts, the second compressor stops, the first solenoid valve is closed, the second solenoid valve is opened, and the third solenoid valve is closed. In this mode, the high temperature discharged by the first compressor The high-pressure refrigerant first enters the first refrigerant passage, then enters the second refrigerant passage through the second solenoid valve, and then enters the cold energy recovery heat exchanger through the second one-way valve to establish a dual-channel variable-capacity operation refrigerant circulation loop; The refrigerant passes through the first refrigerant channel and the second refrigerant channel, and exchanges heat twice with the water in the shell-side channel, and transfers the heat energy recovered by the cold energy recovery heat exchanger during the cold water production process of the first subsystem to the water. The hot water produced in the shell-side channel of the main body of the heat exchanger.

The beneficial effects of the present invention are:

1. The dual-channel variable-capacity heat exchanger of the present invention operates in the dual-channel variable-capacity mode, which can effectively utilize 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 unit operates as a whole. The efficiency is greatly improved, thereby realizing the energy-efficient operation of the heat pump system.

2. The dual-channel variable-capacity heat exchanger of the present invention utilizes the dual-channel variable-capacity heat exchanger operating in the variable-capacity mode and the cooling capacity recovery heat exchanger to achieve partial cooling capacity recovery, which can greatly improve the refrigerant efficiency in the subsystem. Subcooling degree, thereby increasing the cooling capacity of the system.

3. The dual-channel variable-capacity heat exchanger of the present invention can make two sets of refrigeration systems share a set of water-cooled condensers to realize coupled operation, and use the cold energy recovery heat exchanger to reduce the size of the finned evaporator, thereby reducing the size of the finned evaporator. The purpose of the system size is to make the combined cooling and heating system 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 the process flow chart of chocolate processing;

Figure 2 is a system schematic diagram of a cooling capacity recovery variable-capacity air source heat pump system;

Fig. 3 is a schematic diagram of the assembly structure of a cooling capacity recovery variable-capacity air source heat pump system;

4 is a schematic structural diagram of a dual-channel variable-capacity heat exchanger of the present invention;

FIG. 5 is a schematic diagram of the operation mode of the cooling capacity recovery variable-capacity air source heat pump system.

The reference numbers of the components in the above figures: 1-first subsystem, 10-first compressor, 11-first four-way valve, 12-first expansion valve, 13-cold recovery heat exchanger, 14- Cold water circulation pipeline, 15-first gas-liquid separator, 16-first temperature bulb, 17-first accumulator, 18-first defrost one-way solenoid valve, 2-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 bulb, 27-Second accumulator, 28-Second defrost one-way solenoid valve, 3-Dual-channel variable capacity heat exchanger, 30-Heat exchanger body, 31-First refrigerant channel, 32-Second refrigeration Agent channel, 33-first solenoid valve, 34-second solenoid valve, 35-third solenoid valve, 36-first check valve, 37-second check valve, 38-hot water circulation pipeline, 39- Hot water circulation pump.

Detailed ways

In order to better understand the above technical solutions of the present invention, further detailed description is given below in conjunction with the accompanying drawings and embodiments. FIG. 2 and FIG. 3 are an embodiment of the cooling energy recovery variable-capacity air source heat pump system of the present invention, which includes a first subsystem 1 composed of a first compressor 10 and a cooling energy recovery heat exchanger 13, and a second compressor The second subsystem 2 composed of 20 and finned heat exchanger 23, as shown in FIG. 2, the first subsystem 1 and the second subsystem 2 jointly use a dual-channel variable capacity heat exchanger 3 as the Water-cooled condenser; the double-channel variable-capacity heat exchanger 3 includes a heat exchanger body 30 and a set of control valve groups consisting of solenoid valves and one-way valves; the heat exchanger body 30 includes a channel placed in the same shell side The refrigerant in the two refrigerant tube-side channels is independent of each other, and the refrigerant in the two refrigerant tube-side channels exchanges heat with the water in the shell-side channels at the same time; the shell-side channels of the heat exchanger main body 30 pass through the hot water circulation pipeline. 38 and the 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-side channels through the control valve group to establish a dynamically controllable refrigerant cycle 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 production line as an example, the production process of 1T raw materials from processing to final packaging into products needs to stabilize 100KW of heat and 50KW of cooling. In this embodiment, the first sub-system 1 adopts a casing 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 and hardening, and packaging of chocolate processing. Supply; the second subsystem 2 uses a fin 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 cooling and heating requirements.

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 The heat exchanger body 30 is provided with two independent first refrigerant passages 31 and second refrigerant passages 32, and the two refrigerant tube-side passages 31 and 32 are placed in a common in the shell side channel; the control valve group includes three solenoid valves and two one-way valves connected to the refrigerant tube side channel; the solenoid valve includes a first solenoid valve connected to the outlet of the first refrigerant channel 31 valve 33, a second solenoid valve 34 connected between the outlet of the first refrigerant passage 31 and the inlet of the second refrigerant passage 32, and a third solenoid valve 35 connected to the outlet of the second refrigerant passage 32; the single The check valve includes a first check valve 36 connected to the inlet of the second refrigerant passage 32, and a second check valve 37 connected in parallel between the outlet of the second refrigerant passage 32 and the outlet of the first solenoid valve 33; the first The discharge port of the compressor 10 is connected to the inlet of the first refrigerant passage 31 through the first four-way valve 11; the outlet of the first solenoid valve 33 and the outlet of the second one-way valve 37 are connected in parallel, and then pass through the first expansion valve. 12 is connected to the refrigerant passage of the cold energy recovery heat exchanger 13, and then connected to the air inlet of the first compressor 10 through the first four-way valve 11; the exhaust port of the second compressor 20 is connected 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 passage of the fin heat exchanger 23 through the second expansion valve 22, and then connected to the first through the second four-way valve 21. The intake port of the second compressor 20 .

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

According to the embodiment of the cold energy recovery type variable capacity air source heat pump system of the present invention shown in FIG. 2 , a first accumulator 17 is provided on the connecting pipeline between the first refrigerant passage 31 and the first expansion valve 12 , a second accumulator 27 is provided on the connecting pipeline between the second refrigerant passage 32 and the second expansion valve 22 .

According to the embodiment of the cooling capacity recovery 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) Cold and heat 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 passage 31 - First solenoid valve 33 - First accumulator 17 - First expansion valve 12 - Cold energy recovery heat exchanger 13 - First four Through valve 11-first gas-liquid separator 15-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 energy recovery heat exchanger 13 during 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) 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 passage 32 - the third solenoid valve 35 - the second accumulator 27 - the second expansion valve 22 - the fin type changer Heater 23-second four-way valve 21-second gas-liquid separator 25-second compressor 20;

In this mode, the refrigerant in the second refrigerant passage 32 exchanges heat with the water in the shell-side passage, and transfers the heat energy absorbed by the fin 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 main body 30.

(3) Dual-system constant volume hot and cold water mode: the first compressor 10 and the second compressor 20 are started at the same time, the first solenoid valve 33 is opened, the second solenoid valve 34 is closed, and the third solenoid valve 35 is opened;

The refrigerant circulation path of the first subsystem 1 is as follows:

First compressor 10 - First four-way valve 11 - First refrigerant passage 31 - First solenoid valve 33 - First accumulator 17 - First expansion valve 12 - Cold energy recovery heat exchanger 13 - First four Through valve 11-first gas-liquid separator 15-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 passage 32 - the third solenoid valve 35 - the second accumulator 27 - the second expansion valve 22 - the fin type changer 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 in the cold water production process of the first subsystem 1 is recovered to the heat exchanger 13 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 fin heat exchanger 23 from the air source is transferred to the hot water produced in the shell side channel of the heat exchanger body 30 .

(4) Dual-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, and the third solenoid valve 35 is closed, and the refrigerant in this mode circulates 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 discharge port of the first compressor 10 of the cooling-capacity 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 the first stage of heat exchange is performed through the first refrigerant passage 31, a 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 passage 32 exchanges sufficient heat with the water side of the heat exchanger body 30 again, condenses into a refrigerant liquid of high pressure and normal temperature, flows through the second one-way valve 37 and then undergoes the throttling action of the first expansion valve 12 . It turns into a low-pressure refrigerant liquid, enters the sleeve-type evaporator as the cold energy 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 first gas-liquid separator 15. An air inlet of the compressor 10 forms a refrigerant circulation path operating in the dual-channel variable capacity mode; in this mode, the refrigerant passes through the first refrigerant passage 31 and the second refrigerant passage 32, and communicates with the water in the shell side passage. Two heat exchanges are performed, and the heat energy recovered by the cold energy recovery heat exchanger 13 during 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 .

The cooling capacity recovery variable-capacity air source heat pump system of the present invention utilizes the dual-channel variable-capacity heat exchanger 3 operating in the variable-capacity mode, which can greatly improve the subcooling degree of the refrigerant in the first subsystem 1, thereby improving the system's performance. cooling capacity. When the second subsystem 2 is shut down, the dual-channel variable capacity mode can effectively utilize 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 the 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, so as to ensure the heating capacity of the unit at the same time. Reduce the overall system size of the heat pump system:

The variation range of the heat exchange area S of the fin heat exchanger 23 is 0 to W ₂ /q,

The variation range of the heat exchange area S ₁ of the cold energy recovery heat exchanger 13 is 0～(W ₁ -W ₂ )/q ₁ ,

Wherein, the unit heating capacity Q ₁ =W ₁ +P _i , kw; W ₁ is the cooling capacity of the evaporator side during the system heating operation, kw; P _i is the system heating operation input power, kw; W ₂ is the refrigeration recovery Cooling capacity, kw; S=W ₂ /q is the heat exchange area of the fin heat exchanger 23, m ² ; q is the cooling capacity per unit heat exchange area on the evaporating side under heating conditions, kw/m ² ; S ₁ =(W ₁ -W ₂ )/q ₁ is the heat exchange area of the cooling capacity recovery heat exchanger 13 , m ² ; q ₁ is the cooling capacity per unit heat exchange area of the cooling capacity recovery heat exchanger 13 , kw/m ² .

Those skilled in the art should realize that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than being used to limit the present invention. The changes and modifications will fall within the protection scope of the claims of the present invention.

Claims (2)

1. The utility model provides a binary channels variable capacity heat exchanger for take air source heat pump hot-water heating system of cold volume recovery, air source heat pump hot-water heating system include the first subsystem that first compressor and cold volume recovery heat exchanger constitute, the second subsystem that second compressor and finned heat exchanger constitute, its characterized in that:

the double-channel variable-capacity heat exchanger comprises a shell-and-tube heat exchanger serving as a heat exchanger main body and a control valve group connected to a refrigerant tube pass channel of the shell-and-tube heat exchanger;

the heat exchanger main body is internally provided with a first refrigerant channel and a second refrigerant channel which are mutually independent, and the two refrigerant tube pass channels are arranged in a common shell pass channel; the first subsystem and the second subsystem are connected to two refrigerant tube pass channels through the control valve group to establish a dynamically controllable refrigerant circulation loop;

the refrigerants in the two refrigerant tube pass channels exchange heat with water in the shell pass channel at the same time; a shell pass channel of the heat exchanger main body establishes hydrophily heat supply circulation through a hot water circulation pipeline and a hot water circulation pump;

the control valve group comprises three electromagnetic valves and two one-way valves which are connected with a refrigerant tube pass channel; the electromagnetic valves comprise a first electromagnetic valve connected to the outlet of the first refrigerant channel, a second electromagnetic valve connected between the outlet of the first refrigerant channel and the inlet of the second refrigerant channel, and a third electromagnetic valve connected to the outlet of the second refrigerant channel; the check valve comprises a first check valve connected to the inlet of the second refrigerant channel and a second check valve connected between the outlet of the second refrigerant channel and the outlet of the first electromagnetic valve in parallel;

a refrigerant discharge pipe path of the first compressor is connected to an inlet of the first refrigerant path through a first four-way valve; after the outlet of the first electromagnetic valve and the outlet of the second one-way valve are connected in parallel, the first electromagnetic valve and the second one-way valve are connected to a refrigerant channel of the cold energy recovery heat exchanger through a first expansion valve; a refrigerant discharge pipeline of the second compressor is connected to an inlet of the first check valve through a second four-way valve; an outlet of the third electromagnetic valve is connected to a refrigerant channel of the finned heat exchanger through a second expansion valve;

the air source heat pump hot water system realizes dynamic multi-mode operation of the double-channel variable-capacity heat exchanger by changing the on-off state of the control valve group;

the heat exchanger main body adopts a vertical structure with a shell pass channel communicated up and down, the first refrigerant channel is arranged at the upper part of the shell pass channel, and the second refrigerant channel is arranged at the lower part of the shell pass channel; high-temperature sensible heat of the refrigerant is transferred to water on the upper part of the shell pass channel in the first refrigerant channel to form a high-temperature sensible heat exchange zone; the latent heat of condensation of the refrigerant is transferred to water at the lower part of the shell pass channel in the second refrigerant channel to form a latent heat of condensation heat exchange zone.

2. The two-pass variable capacity heat exchanger of claim 1, wherein the dynamic multi-mode operation includes four modes of operation:

(1) the first subsystem cold and hot equalization mode: the method comprises the following steps that a first compressor is started, a second compressor is stopped, a first electromagnetic valve is opened, a second electromagnetic valve is closed, high-temperature and high-pressure refrigerants discharged by the first compressor circularly enter a first refrigerant channel in the mode, and then enter a cold recovery heat exchanger through the first electromagnetic valve and a first expansion valve to establish a first subsystem refrigerant circulating loop; the refrigerant in the first refrigerant channel exchanges heat with water in the shell pass channel, and heat energy recovered by the cold energy recovery heat exchanger in the cold water preparation process of the first subsystem is transferred to hot water prepared in the shell pass channel of the heat exchanger main body;

(2) the air source hot water mode of the second subsystem is as follows: the first compressor stops, the second compressor starts, the second electromagnetic valve closes, the third electromagnetic valve opens, in this mode, the high-temperature and high-pressure refrigerant discharged by the second compressor enters the second refrigerant channel through the first one-way valve, and then enters the finned heat exchanger through the third electromagnetic valve and the second expansion valve, and a second subsystem refrigerant circulation loop is established; the refrigerant in the second refrigerant channel exchanges heat with water in the shell-side channel, and the heat energy absorbed by the fin-type heat exchanger of the second subsystem from an air source is transferred to hot water prepared in the shell-side channel of the heat exchanger main body;

(3) a dual-system constant-volume cold and hot water mode: the first compressor and the second compressor are started simultaneously, the first electromagnetic valve is opened, the second electromagnetic valve is closed, and the third electromagnetic valve is opened; in the mode, high-temperature and high-pressure refrigerant discharged by the first compressor circularly enters the first refrigerant channel and then enters the cold recovery heat exchanger through the first electromagnetic valve and the first expansion valve to establish a first subsystem refrigerant circulating loop; high-temperature and high-pressure refrigerant discharged by the second compressor enters a second refrigerant channel through the first one-way valve and then enters the finned heat exchanger through a third electromagnetic valve and a second expansion valve to establish a second subsystem refrigerant circulation loop; the refrigerant in the first refrigerant channel exchanges heat with water in the shell pass channel, and the heat energy recovered by the cold energy recovery heat exchanger in the cold water preparation process of the first subsystem is transferred to the hot water prepared in the shell pass channel of the heat exchanger main body; meanwhile, the refrigerant in the second refrigerant channel exchanges heat with water in the shell pass channel, and the heat energy absorbed by the fin type heat exchanger of the second subsystem from an air source is transferred to hot water prepared in the shell pass channel of the heat exchanger main body;

(4) two-channel variable-capacity operation mode: in the mode, high-temperature and high-pressure refrigerant discharged by the first compressor firstly enters a first refrigerant channel, then enters a second refrigerant channel through the second electromagnetic valve and then enters a cold energy recovery heat exchanger through a second one-way valve, so that a two-channel variable-capacity operation refrigerant circulation loop is established; the refrigerant carries out heat exchange with water in the shell pass channel twice through the first refrigerant channel and the second refrigerant channel, and heat energy recovered by the cold energy recovery heat exchanger in the cold water preparation process of the first subsystem is transferred to hot water prepared in the shell pass channel of the heat exchanger main body.

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