CN107356016A - A kind of evaporator and the changeable heat exchange unit of loop circuit heat pipe - Google Patents

Abstract

The invention relates to a switchable heat exchange unit between an evaporator and a loop heat pipe, comprising a main heat exchanger, a precooling heat exchanger and a reheating heat exchanger, the precooling heat exchanger, the main heat exchanger and the reheating heat exchanger The heat exchange fluid passages of the heat exchanger are connected in series in sequence, and the refrigerant heat exchange passages of the precooling heat exchanger, the main heat exchanger and the reheat heat exchanger are connected through refrigerant connecting pipes, and are switched through refrigerant pipelines. Form independent evaporator mode or combined mode of evaporator plus loop heat pipe. Compared with the prior art, the present invention can realize the conversion of the independent evaporator mode and the combined mode of the evaporator plus loop heat pipe under different conditions through four three-way valves, thereby reducing unnecessary energy loss of the system.

Description

A heat exchange unit with switchable evaporator and loop heat pipe

technical field

The invention relates to a heat exchange unit, in particular to a heat exchange unit in which an evaporator and a loop heat pipe can be switched.

Background technique

The heat pipe is a new type of heat transfer element. The main principle is to use the phase change process of the medium condensing at the cold end after evaporating at the hot end (that is, using the latent heat of evaporation and latent heat of condensation of the liquid) to conduct heat quickly, and its heat conduction capacity exceeds any The thermal conductivity of metals is known. The loop heat pipe is a high-efficiency phase change heat transfer device. It is composed of an evaporator and a condenser. It is connected into a loop through a gas-liquid transmission pipeline. It uses the evaporation and condensation of the working fluid to transfer heat. A large amount of heat is transferred over a long distance. Loop heat pipes have become the heat transfer element of choice in aviation thermal control systems and are playing an increasingly important role in cooling systems for ground electronics.

In the vapor compression refrigeration device, the evaporator utilizes the low-pressure evaporation of the refrigerant to form a low temperature to cool the heat exchange fluid. The larger the area of the evaporator, the higher the evaporation pressure of the refrigeration system and the higher the efficiency of the refrigeration cycle. When the evaporator is used for heat and humidity treatment of the air, it can not only reduce the temperature of the air, but also condense the moisture in the air when the surface temperature of the evaporator is lower than the dew point temperature, so as to realize the dehumidification function, and the lower the evaporation temperature, the better the condensation effect more significant.

In the actual application process, in some cases, it is necessary to use all the heat exchange area as an evaporator to increase the evaporation temperature as much as possible and improve the cycle efficiency; under the condition of dehumidification and reheating, it is necessary to use the low evaporation temperature to increase the condensation efficiency. Heat recovery is achieved by reheating. For example, in the heat pump cycle of a heat pump dryer, in order to make the dehumidification effect better, the evaporation temperature is generally lower, and the air is first cooled and dehumidified before being heated, which brings unnecessary energy loss.

Contents of the invention

The object of the present invention is to provide a heat exchange unit that can be switched between an independent evaporator and a combination of an evaporator plus a loop heat pipe in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions: a heat exchange unit with switchable evaporator and loop heat pipe, the heat exchange unit includes a main heat exchanger, a precooling heat exchanger and a reheating heat exchanger, the The heat exchange fluid passages of the pre-cooling heat exchanger, the main heat exchanger and the reheat heat exchanger are connected in series in sequence, and the refrigerant heat exchange passages of the pre-cooling heat exchanger, the main heat exchanger and the reheat heat exchanger pass through The refrigerant connection pipes are connected, and the independent evaporator mode or the combination mode of the evaporator plus the loop heat pipe is formed through the switching of the refrigerant pipeline.

Preferably, the inlet of the heat exchange fluid passage is arranged on the precooling heat exchanger, and the outlet of the heat exchange fluid passage is arranged on the reheat heat exchanger.

The fluid flowing in the heat exchange fluid channel is air, and the air is transported from the inlet of the heat exchange fluid channel to the outlet of the heat exchange fluid channel by the fan.

The connection sequence of the refrigerant heat exchange channels is as follows: port No. 3 of the No. 1 three-way valve is connected to end a of the refrigerant channel of the main heat exchanger; No. 2 port of the No. 1 three-way valve is connected to the pre-cooling heat exchanger The a end of the refrigerant passage of the refrigerant channel is connected with the third port of the third three-way valve; the b end of the refrigerant passage of the pre-cooling heat exchanger is connected with the first port of the second three-way valve, and the second three-way valve The No. 2 port of the main heat exchanger is connected to the a end of the refrigerant channel of the main heat exchanger, and the b end of the refrigerant channel of the main heat exchanger is respectively connected to the No. 1 port of the No. 3 three-way valve and the third port of the No. 4 three-way valve. The No. 2 port of the No. 3 three-way valve is connected to the a-end of the refrigerant passage of the reheat heat exchanger, and the b-end of the refrigerant passage of the reheat heat exchanger is respectively connected to the No. 2 tee The No. 3 port of the valve and the No. 1 inlet of the No. 4 three-way valve are connected.

A refrigerant pump is provided on the connecting pipeline between end b of the refrigerant channel of the reheat heat exchanger and port No. 3 of the No. 2 three-way valve.

In the independent evaporator mode, the No. 3 port of the No. 1 three-way valve, No. 3 port of the No. 2 three-way valve, No. 3 port of the No. 3 three-way valve and No. 3 port of the No. 4 three-way valve are closed.

In the combination mode of the evaporator plus the loop heat pipe, the No. 2 port of the No. 1 three-way valve, the No. 2 port of the No. 2 three-way valve, the No. 1 port of the No. 3 three-way valve, and the No. 1 port of the No. 4 three-way valve Mouth closed.

The inlet of the refrigerant heat exchange channel is connected to the No. 1 port of the No. 1 three-way valve, and the outlet of the refrigerant heat exchange channel is connected to the No. 2 port of the No. 4 three-way valve. In this connection mode, the refrigerant heat exchange channel The fluid flow in the heat exchange fluid channel is co-current with the air flow in the heat exchange fluid channel.

The inlet of the refrigerant heat exchange channel is connected to the No. 2 port of the No. 4 three-way valve, and the outlet of the refrigerant heat exchange channel is connected to the No. 1 port of the No. 1 three-way valve. In this connection mode, the fluid flow in the refrigerant heat exchange channel and the air flow in the heat exchange fluid channel are countercurrent.

The types of the precooling heat exchanger, main heat exchanger and reheat heat exchanger include finned tube heat exchangers, microchannel heat exchangers, plate heat exchangers, shell and tube heat exchangers, falling film heat exchangers Heater, casing heat exchanger.

The heat exchange unit has the following two working modes:

1. Independent evaporator mode: the inlet of the heat exchange unit, the refrigerant passages of the pre-cooling heat exchanger, the main heat exchanger and the reheat heat exchanger, and the outlet of the heat exchange unit are connected together sequentially through connecting pipes and three-way valves to form a Independent evaporator. The heat exchange fluid passes through the pre-cooling heat exchanger, the main heat exchanger and the reheat heat exchanger in sequence.

2. Combined mode of evaporator plus loop heat pipe: the main heat exchanger acts as an evaporator alone, and its refrigerant channel is connected to the inlet and outlet of the heat exchange unit through connecting pipes and three-way valves; pre-cooling heat exchanger, reheating heat exchange The refrigerant pump and the refrigerant pump are directly connected through a connecting pipe and a three-way valve to form a loop heat pipe. The refrigerant evaporates in the pre-cooling heat exchanger and enters the reheating heat exchanger. The pump re-delivers the liquid refrigerant to the pre-cooling heat exchanger. The heat exchange fluid passes through the pre-cooling heat exchanger, the main heat exchanger and the reheat heat exchanger in sequence.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

The conversion between the independent evaporator mode and the evaporator plus loop heat pipe mode is realized by switching the refrigerant pipeline. Among them, the role of the independent evaporator mode is that all heat transfer areas can be used as evaporators to increase the evaporation temperature as much as possible and improve cycle efficiency; the role of the evaporator plus loop heat pipe combination mode is to use the The low evaporating temperature increases the condensation efficiency, and realizes precooling and reheating before and after the evaporator through the combination of loop heat pipes, thereby reducing unnecessary energy loss of the system.

Description of drawings

Fig. 1 is the connection schematic diagram of embodiment 1;

Fig. 2 is the schematic diagram of the principle of independent evaporator mode in embodiment 1;

Fig. 3 is the schematic diagram of the principle of the combination mode of evaporator plus loop heat pipe in embodiment 1;

FIG. 4 is a schematic connection diagram of Embodiment 2.

Among them, 1 is the pre-cooling heat exchanger, 11 is the a end of the refrigerant passage of the pre-cooling heat exchanger; 12 is the b end of the refrigerant passage of the pre-cooling heat exchanger; 2 is the main heat exchanger, and 21 is the main End a of the refrigerant channel of the heat exchanger, 22 is the end b of the refrigerant channel of the main heat exchanger, 3 is the reheat heat exchanger, 31 is the a end of the refrigerant channel of the reheater, and 32 is the reheater The b end of the refrigerant channel of the heat exchanger, 4 is the No. 1 three-way valve, 41 is the No. 1 port of the No. 1 three-way valve, 42 is the No. 2 port of the No. 1 three-way valve, and 43 is the No. 1 three-way valve The No. 3 port of the valve, 5 is the No. 2 three-way valve, 51 is the No. 1 port of the No. 2 three-way valve, 52 is the No. 2 port of the No. 2 three-way valve, and 53 is the No. 3 port of the No. 2 three-way valve. 6 is No. 3 three-way valve, 61 is No. 1 port of No. 3 three-way valve, 62 is No. 2 port of No. 3 three-way valve, 63 is No. 3 port of No. 3 three-way valve, and 7 is No. 4 three-way valve Valve, 71 is the No. 1 port of the No. 4 three-way valve, 72 is the No. 2 port of the No. 4 three-way valve, 73 is the No. 3 port of the No. 4 three-way valve, 8 is the heat exchange fluid channel, 81 is the fan, 9 101 is the inlet of the refrigerant heat exchange channel, and 102 is the outlet of the refrigerant heat exchange channel.

detailed description

The following is a detailed description of the embodiments of the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following implementation example.

Example 1

A heat exchange unit with switchable evaporator and loop heat pipe, its structure is shown in Figure 1, including main heat exchanger 2, pre-cooling heat exchanger 1 and reheating heat exchanger 3, pre-cooling heat exchanger 1 , the heat exchange fluid passages 8 of the main heat exchanger 2 and the reheat heat exchanger 3 are connected in sequence, and the refrigerant heat exchange passages of the precooling heat exchanger 1, the main heat exchanger 2 and the reheat heat exchanger 3 form independent evaporation The heat exchanger mode or the combination mode of the evaporator and the loop heat pipe, wherein the type of the precooling heat exchanger 1, the main heat exchanger 2 and the reheating heat exchanger 3 are finned tube heat exchangers.

The inlet of the heat exchange fluid passage 8 is arranged on the precooling heat exchanger 1 , and the outlet of the heat exchange fluid passage 8 is arranged on the reheat heat exchanger 3 . The fluid flowing in the heat exchange fluid channel 8 is air, and the fan 81 transports the air from the inlet of the heat exchange fluid channel 8 to the outlet of the heat exchange fluid channel 8 .

The connection sequence of the refrigerant heat exchange channels is as follows: the inlet 101 of the refrigerant heat exchange channel is connected to the No. 1 port 41 of the No. 1 three-way valve, and the outlet 102 of the refrigerant heat exchange channel is connected to the No. 2 port 72 of the No. 4 three-way valve. , in this connection mode, the fluid flow in the refrigerant heat exchange channel and the air flow in the heat exchange fluid channel 8 are co-current. The No. 3 port 43 of the No. 1 three-way valve is connected to the a-end 21 of the refrigerant passage of the main heat exchanger; the No. 2 port 42 of the No. 1 three-way valve is respectively connected to the a-end 11 of the refrigerant passage of the pre-cooling heat exchanger. and the No. 3 port 63 of the No. 3 three-way valve; the b-end 12 of the refrigerant channel of the precooling heat exchanger is connected with the No. 1 port 51 of the No. 2 three-way valve, and the No. 2 port 52 of the No. 2 three-way valve is connected with The a-end 21 of the refrigerant channel of the main heat exchanger is connected, and the b-end 22 of the refrigerant channel of the main heat exchanger is respectively connected with the No. 1 port 61 of the No. 3 three-way valve and the No. 3 port 73 of the No. 4 three-way valve , the No. 2 port 62 of the No. 3 three-way valve is connected to the a-end 31 of the refrigerant passage of the reheat heat exchanger, and the b-end 32 of the refrigerant passage of the reheat heat exchanger is respectively connected to the No. 3 port of the No. 2 three-way valve. Port 53 and No. 1 inlet of No. 4 three-way valve 7 are connected. A refrigerant pump 9 is provided on the connecting pipeline between the b-end 32 of the refrigerant channel of the reheat heat exchanger and the third port 53 of the second three-way valve.

The principle of the independent evaporator mode of this embodiment is shown in Figure 2, wherein the No. 3 port 43 of the No. 1 three-way valve, the No. 3 port 53 of the No. 2 three-way valve, the No. 3 port 63 of the No. 3 three-way valve and No. 3 port 73 of No. 4 three-way valve is closed. At this time, the heat exchange fluid passes through the pre-cooling heat exchanger 1, the main heat exchanger 2 and the reheat heat exchanger 3 in sequence, and the heat exchange area is large, which can increase the evaporation temperature as much as possible and improve the cycle efficiency.

The principle of the evaporator plus loop heat pipe combination mode of this embodiment is shown in Figure 3, No. 2 port 42 of No. 1 three-way valve, No. 2 port 52 of No. 2 three-way valve, and No. 1 port of No. 3 three-way valve No. 1 port 71 of No. 61 and No. four three-way valves is closed. The No. 1 three-way valve 4 connects the inlet 101 of the refrigerant heat exchange channel to the a-end 21 of the refrigerant channel of the main heat exchanger, and the No. 2 three-way valve 5 makes the b-end of the refrigerant channel of the pre-cooling heat exchanger 12 Through the refrigerant pump 9, only the b end 32 of the refrigerant passage of the reheat heat exchanger is connected, and the No. 3 three-way valve 6 makes the a end 31 of the refrigerant passage of the reheat heat exchanger only connected with the precooling heat exchanger The a-end 11 of the refrigerant passage of the main heat exchanger communicates with the a-end 11 of the refrigerant passage, and the No. 4 three-way valve 7 makes the outlet 102 of the refrigerant heat exchange passage only communicate with the b-end 22 of the refrigerant passage of the main heat exchanger. The refrigerant enters the heat exchange unit from the inlet 101 of the refrigerant heat exchange channel, directly enters the main heat exchanger 10 after passing through the No. 1 three-way valve 4, and then directly flows from the outlet 102 of the refrigerant heat exchange channel through the No. flow out of the heat exchange unit. At this time, the main heat exchanger is used alone as the evaporator of the system. At the same time, the precooling heat exchanger 1 and the reheating heat exchanger 3 are directly connected to the second three-way valve 5 and the third three-way valve 6 through connecting pipes to form a loop heat pipe. The precooling heat exchanger 1 is used as the evaporation end of the loop heat pipe, and the reheat heat exchanger 3 is used as the condensation end of the loop heat pipe. The liquid heat exchange fluid absorbs heat in the precooling heat exchanger 1 and becomes a gaseous state. Under power, it enters the reheating heat exchanger 3, condenses and releases heat, and the liquid heat exchange fluid is transported back to the precooling heat exchanger 1 through the refrigerant pump 9 to complete the circulation of the loop heat pipe. At this time, the heat exchange fluid first passes through the precooling heat exchanger 1 to realize precooling before the evaporator, then passes through the main heat exchanger 2 to realize further cooling and dehumidification, and finally passes through the reheating heat exchanger 3 to realize reheating, thereby Reduce unnecessary energy loss of the system.

Example 2

The same connection method is used in Example 1, the difference is: the inlet 101 of the refrigerant heat exchange channel is connected to the second port 72 of the No. 4 three-way valve, and the outlet 102 of the refrigerant heat exchange channel is connected to the No. 1 three-way valve. 1 port connection, as shown in Figure 4.

Compared with Example 1, only the connection sequence of the refrigerant channels of the precooling heat exchanger 1, the main heat exchanger 2, and the reheating heat exchanger 3 has changed, and the functions remain unchanged.

Claims (10)

1. a kind of evaporator and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that the heat exchange unit include main heat exchanger, Precool heat exchanger device and again heat exchanger, the precool heat exchanger device, main heat exchanger and the heat transfer fluid channels of heat exchanger are successively again Series connection, the precool heat exchanger device, main heat exchanger and again the refrigerant heat exchanger passage of heat exchanger by connecting refrigerant lines UNICOM, And switch to form independent evaporator mode or evaporator adds loop circuit heat pipe integrated mode by refrigerant line.

2. a kind of evaporator according to claim 1 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that described The imports of heat transfer fluid channels be arranged on precool heat exchanger device, the outlet of heat transfer fluid channels is arranged on again on heat exchanger.

3. a kind of evaporator according to claim 1 or 2 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that The fluid flowed in described heat transfer fluid channels is air, is delivered to air from the import of heat transfer fluid channels by blower fan The outlet of heat transfer fluid channels.

4. a kind of evaporator according to claim 2 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that described The refrigerant heat exchanger passage order of connection is as follows：The a ends of No. three mouths of No.1 triple valve and the coolant channel of main heat exchanger connect； No. three mouths of No. two mouths of No.1 triple valve respectively with a ends of the coolant channel of precool heat exchanger device and No. three triple valves are connected； The b ends of the coolant channel of precool heat exchanger device are connected with the No.1 mouth of No. two triple valves, No. two mouths of No. two triple valves with The a ends connection of the coolant channel of main heat exchanger, the b ends of the coolant channel of the main heat exchanger respectively with No. three triple valves No. three mouths of No.1 mouth and No. four triple valves connect, the coolant channel of No. two mouths of No. three triple valves and heat exchanger again The connection of a ends, the b ends of the coolant channel of the heat exchanger again No. three mouths and No. four triple valves with No. two triple valves respectively No.1 import connection.

5. a kind of evaporator according to claim 4 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that described The b ends of the coolant channel of heat exchanger and the connecting line of No. three mouths of No. two triple valves are provided with refrigerated medium pump again.

6. a kind of evaporator according to claim 5 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that independent Under evaporator mode, No. three mouths of the No.1 triple valve, No. three mouths of No. two triple valves, No. three mouths and four of No. three triple valves No. three mouths of number triple valve are closed.

7. a kind of evaporator according to claim 5 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that evaporation Device adds under loop circuit heat pipe integrated mode, No. two mouths of the No.1 triple valve, No. two mouths of No. two triple valves, No. three triple valves The No.1 mouth of No.1 mouth and No. four triple valves is closed.

8. a kind of evaporator according to claim 4 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that described The import of refrigerant heat exchanger passage is connected with No.1 triple valve No.1 mouth, outlet and No. four triple valves of refrigerant heat exchanger passage No. two mouth connections.

9. a kind of evaporator according to claim 4 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that described The import of refrigerant heat exchanger passage is connected with No. two mouths of No. four triple valves, outlet and the No.1 triple valve of refrigerant heat exchanger passage No.1 mouth connects.

10. a kind of evaporator according to claim 1 and the changeable heat exchange unit of loop circuit heat pipe, it is characterised in that institute State precool heat exchanger device, main heat exchanger and the type of heat exchanger includes finned tube exchanger, micro-channel heat exchanger, plate-type heat-exchange again Device, shell-and-tube heat exchanger, falling-film heat exchanger or double pipe heat exchanger.