CN216049042U

CN216049042U - Triple-effect heat recovery type air mixing type heat pump drying system

Info

Publication number: CN216049042U
Application number: CN202122314398.4U
Authority: CN
Inventors: 曹祥; 余文
Original assignee: Zhejiang Jiyan Energy Technology Co ltd
Current assignee: Zhejiang Jiyan Energy Technology Co ltd
Priority date: 2021-09-24
Filing date: 2021-09-24
Publication date: 2022-03-15
Anticipated expiration: 2031-09-24

Abstract

The utility model relates to a triple-effect heat recovery type air-mixing heat pump drying system, which comprises a shell, and a refrigerant cycle, a loop heat pipe cycle and an air cycle which are arranged in the shell, wherein the refrigerant cycle comprises an evaporator, a gas-liquid separator, a compressor, a condenser, a supercooling reheating coil and a throttling element which are sequentially connected; the air output by the drying room in the air circulation carries out first-effect heat recovery in an air flow channel of the loop heat pipe circulation, carries out second-effect heat recovery in an air flow channel of the evaporator, and carries out third-effect heat recovery in an air flow channel of the supercooling reheating coil. Compared with the prior art, the utility model greatly improves the energy utilization rate in the drying process through triple-effect heat recovery, and the design of the plurality of metal plates of the top plate and the left and right side plates can fully utilize the external wind field conditions to reduce the power consumption of the fan and conveniently maintain the optimal air mixing ratio.

Description

Triple-effect heat recovery type air mixing type heat pump drying system

Technical Field

The utility model relates to a heat pump drying system, in particular to a triple-effect heat recovery type air mixing type heat pump drying system.

Background

Closed drying system based on heat pump technology, for example the closed system that CN209415903U disclosed, utilize the heat pump evaporimeter to absorb sensible heat and a large amount of latent heat in the baking house return air, the baking house return air with high temperature and high humidity is handled into low temperature and low humidity's air, utilize the absorptive heat to become the state of high temperature and low humidity with the air heating through the condenser, send back the baking house at last and carry out the material and dry, the energy utilization of stoving process is higher, and compare in open heat pump drying system, the system receives environmental impact lessly.

In an application scenario with a large air volume requirement, since the area of the heat exchanger is limited by the unit size and the operation range of the compressor, the simple closed heat pump drying system is no longer applicable, and an air mixing form needs to be introduced (see CN 107642925B): the split-flow part of return air flows through the evaporator for cooling and dehumidifying, is mixed with the rest return air after being processed, and enters the condenser together for heating, so that the air quantity difference design of the evaporator and the condenser is realized.

In a closed heat pump drying system, a large amount of high-grade cold energy is contained in low-temperature and low-humidity air behind an evaporator. In a simple closed system this part of the cold energy is absorbed by the condenser, which is disadvantageous for heating the condenser; in a mixed air heat pump drying system, this cold energy is wasted when mixed with another return air. To utilize this portion of cold energy, CN107130415B discloses a device for pre-cooling return air by utilizing evaporator back air cold energy through a heat pipe in the field of clothes drying. However, due to the characteristics of the heat pipes, air after the evaporator cannot be reheated to the normal return air temperature (the phase change temperature needs to be lower than the return air temperature), and the return air after the evaporator still has available cold energy.

SUMMERY OF THE UTILITY MODEL

The present invention is directed to overcome the above-mentioned drawbacks of the prior art, and provides a triple-effect heat recovery type air-mixing heat pump drying system, in which a loop heat pipe is used for primary heat-moisture recovery (first-effect heat recovery), an evaporator is used for deep latent heat recovery (second-effect heat recovery), and a supercooling reheating coil is used for deep cold energy recovery (third-effect heat recovery), so as to improve energy efficiency during drying. In addition, the utility model can conveniently adjust the air inlet direction and the air mixing ratio, can fully utilize the wind field conditions under different external wind field environmental conditions, reduces the power consumption of the fan and keeps the optimal air mixing ratio.

The purpose of the utility model can be realized by the following technical scheme:

the utility model aims to protect a triple-effect heat recovery type air mixing type heat pump drying system, which comprises a shell, and a refrigerant cycle, a loop heat pipe cycle and an air cycle which are arranged in the shell, wherein the triple-effect heat recovery type air mixing type heat pump drying system specifically comprises:

the refrigerant cycle comprises an evaporator, a gas-liquid separator, a compressor, a condenser, a supercooling reheating coil and a throttling element which are connected in sequence, wherein the throttling element is connected with the evaporator to form a cycle;

the loop heat pipe circulation comprises a loop heat pipe precooler and a loop heat pipe reheater which are connected with each other;

the air circulation comprises a drying room, the drying room is connected with an air flow passage of a refrigerant circulation and a loop heat pipe circulation, in the connection sequence of the air flow passage, a loop heat pipe precooler is arranged in front of an evaporator, a loop heat pipe reheater is arranged between the evaporator and a supercooling reheating coil, the air output by the drying room is subjected to first effective heat recovery in the air flow passage of the loop heat pipe circulation, second effective heat recovery is carried out in the air flow passage of the evaporator, and third effective heat recovery is carried out in the air flow passage of the supercooling reheating coil.

The loop heat pipe pre-cooler is arranged in front of the evaporator in the air circulation, and the loop heat pipe re-heater is arranged behind the evaporator. The loop heat pipe utilizes partial cold energy in the air after being cooled and dehumidified by the evaporator to pre-cool return air so as to carry out primary heat and humidity recovery.

Further, the temperature of return air flowing through the evaporator in the air circulation is reduced to the dew point, water vapor in the air is condensed to release heat, and the evaporator recovers the part of latent heat of humidity effect.

Furthermore, an overcooling reheating coil is arranged in the refrigerant cycle and the air cycle, and the overcooling reheating coil recovers residual cold energy in return air after passing through a loop heat pipe and an evaporator and is used for cooling a liquid refrigerant.

Furthermore, water is arranged in the loop heat pipe circulation to serve as a medium, and the loop heat pipe circulation further comprises a water pump, so that the water in the loop heat pipe circulation is driven to flow circularly through the water pump.

Furthermore, the air circulation comprises a first return air channel and a second return air channel, a fan is arranged in the air circulation, and the fan drives the flow circulation of return air in the first return air channel and the second return air channel.

Furthermore, in the first air return channel, an air return outlet of the drying room is sequentially connected with an air channel of the loop heat pipe precooler, an air channel of the evaporator, an air channel of the loop heat pipe reheater, an air channel of the supercooling reheating coil, the fan and an air channel of the condenser, and the air channel of the condenser is connected with an air return inlet of the drying room.

Furthermore, in the second return air channel, a return air outlet of the drying room is sequentially connected with air channels of the fan and the condenser, and the air channel of the condenser is connected with a return air inlet of the drying room.

Furthermore, the first air return channel and the second air return channel are connected to an air channel inlet of the fan, and an air channel outlet of the fan is connected with an air channel inlet of the condenser.

From the air circulation perspective, the air circulation divides into a first return air channel and a second return air channel: in the first air return channel, drying room return air sequentially passes through an air channel of a loop heat pipe precooler, an air channel of an evaporator, an air channel of a loop heat pipe reheater, an air channel of a supercooling reheating coil, a fan and an air channel of a condenser and is finally sent back into the drying room; and the return air of the drying room in the second return air channel passes through the fan and the condenser in turn and then is returned into the drying room. The return air in the first return air channel and the second return air channel is uniformly mixed in the fan section, then passes through the condenser and finally is sent into the drying room.

Furthermore, the loop heat pipe precooler, the evaporator, the loop heat pipe reheater and the supercooling reheating coil pipe are of an outer metal plate integrated structure.

Furthermore, the loop heat pipe precooler, the evaporator, the loop heat pipe reheater and the supercooling reheating coil pipe form an integrated heat exchanger, a condensed water collecting tray is arranged below the structure of the integrated heat exchanger, and a centralized water outlet is arranged on one side of the condensed water collecting tray. Specifically, an integrated heat exchanger composed of a loop heat pipe precooler, an evaporator, a loop heat pipe reheater and a supercooling reheating coil is arranged on the front side of the unit, a condensed water collecting tray is arranged below the integrated heat exchanger, and a centralized water outlet is arranged on the front side of the condensed water collecting tray.

Further, the casing includes structural framework, roof, left and right sides board, backplate and well intermediate spacer, the roof constitutes by the polylith panel beating concatenation with left and right sides board, and the panel beating passes through the bolt fastening on structural framework.

Furthermore, an integrated heat exchanger, a water pump, a condensate water collecting tray, a condenser, a fan, a compressor, a gas-liquid separator, a throttling element, an electric heating box and an electric box are installed inside the shell, the integrated heat exchanger comprises a loop heat pipe precooler, an evaporator, a loop heat pipe reheater and a supercooling reheating coil pipe, and an outer metal plate integrated design is adopted.

Further, roof and left and right sides board design into the modularization form, are about to cut apart into the polylith panel beating with roof and curb plate, and the panel beating passes through the bolt fastening on structural support, confirms the panel beating quantity of installation according to the on-the-spot regulation test result in the concrete implementation.

Furthermore, two forklift holes are reserved on the bottom structure supports on the left side and the right side of the shell respectively.

Furthermore, the loop heat pipe precooler, the evaporator, the loop heat pipe reheater and the supercooling reheating coil adopt finned tube heat exchangers and adopt an outer metal plate integrated design.

Further, the condenser is a micro-channel heat exchanger, and the condenser is horizontally arranged on the bottom bracket.

The fan is a fixed-frequency axial flow fan and is arranged above the condenser, and the air outlet direction of the fan is downward.

Further, the compressor is a vertical fixed-frequency scroll compressor and is provided with a gas-liquid separator, a gas suction port of the compressor is connected with the gas-liquid separator, a gas exhaust port of the compressor is connected with the condenser, and the other end of the gas-liquid separator is connected with the evaporator. The compressor, the gas-liquid separator and the electric box are all arranged at the back position inside the unit shell, and are separated from the air return channel through the middle partition plate of the shell.

Furthermore, the throttling element comprises an electronic expansion valve, a liquid separation head and a liquid separation capillary tube which are sequentially connected, wherein the inlet of the electronic expansion valve is connected with the outlet of a refrigerant channel of the supercooling reheating coil, the outlet of the electronic expansion valve is connected with the liquid separation head, and the liquid separation capillary tube is connected between the liquid separation head and the evaporator.

Further, an electric heater is disposed below the condenser.

The main working flow of the utility model is as follows:

on the air side: the drying room return air is divided into two paths which respectively enter the first return air channel and the second return air channel. The return air entering the first return air channel is firstly cooled through a loop heat pipe precooler, then flows through an evaporator for cooling and dehumidification, and is then heated in two stages through a loop heat pipe reheater and a supercooling reheating coil pipe in sequence, and the temperature returns to be close to the return air temperature of the drying room. The return air treated in the first return air channel is mixed with the return air untreated in the second return air channel, is blown through a condenser under the driving of a fan, is heated to high-temperature low-humidity air required by the process, and is finally sent into a drying room.

On the refrigerant side: the low-temperature low-pressure refrigerant gas flowing out of the evaporator is compressed by the compressor to become high-temperature high-pressure refrigerant gas, then the high-temperature high-pressure refrigerant gas sequentially enters the condenser and the overheating reheating coil, and is condensed into low-temperature high-pressure refrigerant liquid through releasing heat to air flowing through the condenser and the overheating reheating coil and is further supercooled. The low-temperature high-pressure refrigerant flowing out of the supercooling reheating coil enters the evaporator after being throttled by the throttling element to absorb heat in air flowing through the evaporator and is evaporated into low-temperature low-pressure refrigerant gas again to complete refrigerant circulation.

On the loop heat pipe side: the precooler, the reheater and the water pump are communicated in sequence, and water circulates inside. The low-temperature water in the precooler absorbs heat from the air passing through the precooler and becomes high-temperature water, thereby realizing the purpose of precooling and cooling the return air. The high-temperature water flowing out of the precooler enters the reheater, releases heat to the air passing through the reheater, and becomes low-temperature water, so that the aim of reheating and heating the air is fulfilled. And the low-temperature water flowing out of the reheater enters the precooler again to complete circulation. The flow of water between the precooler and the reheater is driven by a water pump.

In specific implementation, the air return opening of the second air return channel is determined to be arranged on the top surface or the side surface according to the environment of an external wind field, and the number of the installed metal plates is adjusted according to the head-on wind speed of the loop heat pipe precooler so as to keep the optimal air mixing proportion.

As another embodiment of the utility model, the condenser can adopt two finned tube heat exchangers, the two finned tube heat exchangers are vertically arranged between the middle partition plate and the back plate and are arranged on two sides of the unit, and system air supply is sent out from the left side and the right side of the unit.

Furthermore, the fan is changed into a volute-free centrifugal fan and is arranged on the middle partition plate, and the middle partition plate is provided with a hole as an air inlet of the centrifugal fan.

Further, the electric heater is installed outside the condenser.

Further, for convenience of installation and space saving, the compressor and the gas-liquid separator are installed between the supercooling reheating coil and the middle partition plate, and the electric box is installed on the outer side of the back plate.

Compared with the prior art, the utility model has the beneficial effects that:

1. compared with a simple air mixing type heat pump drying system, the utility model is provided with the loop heat pipes in front of and behind the evaporator, and can utilize the cold energy of the air behind the evaporator to pre-cool the air in front of the evaporator, thereby improving the Latent heat of condensation ratio (LHR) in the air entering the evaporator.

2. Compared with a simple air mixing type heat pump drying system, the utility model is provided with the supercooling reheating coil, the refrigerant at the outlet of the condenser is supercooled by utilizing the residual cold energy in the air passing through the loop heat pipe and the evaporator, the supercooling degree of the system is increased, and the Coefficient of performance (COP) of the refrigerant cycle is improved

3. The top surface and the left and right side surfaces of the utility model can be set as the air inlets of the second return air channel, thereby fully utilizing the external wind field condition and reducing the power consumption of the fan.

4. The area of the air inlet of the second return air channel can be adjusted through the mounting number of metal plates, so that the optimal air mixing proportion is maintained, and the air conditioner is convenient and flexible to use practically.

In conclusion, the utility model can improve the Latent Heat Ratio (LHR) of the evaporator, improve the refrigerant cycle energy efficiency (COP) and reduce the energy consumption of the fan, thereby greatly improving the dehumidification energy efficiency of the unit (the unit energy consumption dehumidification capacity SMER is in direct proportion to the LHR and the COP). In addition, the utility model also has the advantages of flexible and convenient installation and use.

Drawings

Fig. 1 is a schematic diagram of the principle of the triple-effect heat recovery type air mixing type heat pump drying system of the utility model.

Fig. 2 is a schematic perspective view of the assembly of the unit in embodiment 1.

FIG. 3 is a top plan view (without a top deck) of the unit system layout of example 1.

FIG. 4 is a bottom view of the arrangement of the unit system in the embodiment 1.

Fig. 5 is a schematic perspective view of the assembly of the unit in embodiment 2.

FIG. 6 is a top plan view of the unit system layout (without the top deck) of example 2.

In the figure: 0. the system comprises a unit shell, 0-1 part of a structural frame, 0-2 parts of a top plate, 0-3 parts of a left side plate, a right side plate, 0-4 parts of a back plate, 0-5 parts of a middle partition plate, 0-6 parts of a forklift hole, 1 part of an integrated heat exchanger, 1-1 part of a loop heat pipe precooler, 1-2 parts of an evaporator, 1-3 parts of a loop heat pipe reheater, 1-4 parts of a supercooling reheating coil, 2 parts of a condensate water collecting tray, 3 parts of a condenser, 4 parts of a fan, 5 parts of a compressor, 6 parts of a gas-liquid separator, 7 parts of a throttling element, 7-1 parts of an electronic expansion valve, 7-2 parts of a liquid separating head, 8 parts of electric heating, 9 parts of an electric box, 10 parts of a first return air channel return air, 11 parts of a second return air channel return air, 12 parts of air supply, 13 parts of an air supply, a drying room, 14 parts of a water pump.

Detailed Description

The utility model is described in detail below with reference to the figures and specific embodiments. In the technical scheme, the characteristics such as the part type, the material name, the connection structure and the like which are not explicitly described are all regarded as common technical characteristics disclosed in the prior art.

The triple-effect heat recovery type air mixing type heat pump drying system comprises a shell 0, and a refrigerant cycle, a loop heat pipe cycle and an air cycle which are arranged in the shell 0, and is shown in a figure 1 and a figure 2, wherein the triple-effect heat recovery type air mixing type heat pump drying system specifically comprises:

the refrigerant cycle comprises an evaporator 1-2, a gas-liquid separator 6, a compressor 5, a condenser 3, a supercooling reheating coil 1-4 and a throttling element 7 which are connected in sequence, wherein the throttling element 7 is connected with the evaporator 1-2 to form a cycle;

the loop heat pipe circulation comprises a loop heat pipe precooler 1-1 and a loop heat pipe reheater 1-3 which are connected with each other;

the air cycle comprises a drying room 13, the drying room 13 is connected with an air flow channel of a refrigerant cycle and a loop heat pipe cycle, in the connection sequence of the air flow channel, the loop heat pipe precooler 1-1 is arranged in front of an evaporator 1-2, the loop heat pipe reheater 1-3 is arranged between the evaporator 1-2 and a supercooling reheating coil 1-4, the air output by the drying room 13 is subjected to first effect heat recovery in the air flow channel of the loop heat pipe cycle, is subjected to second effect heat recovery in the air flow channel of the evaporator 1-2, and is subjected to third effect heat recovery in the air flow channel of the supercooling reheating coil 1-4.

Example 1

Referring to fig. 2 to 4, in the embodiment, the triple-effect heat recovery type air mixing heat pump drying system includes a housing 0, and a loop heat pipe precooler 1-1, an evaporator 1-2, a loop heat pipe reheater 1-3, a supercooling reheating coil 1-4, a water pump 14, a condensed water collecting tray 2, a condenser 3, a fan 4, a compressor 5, a gas-liquid separator 6, a throttling element 7, an electric heater 8, and an electric box 9 are installed inside the housing 0.

The shell 0 comprises a structural support 0-1, a top plate 0-2, a left side plate 0-3, a right side plate 0-3, a back plate 0-4 and a middle partition plate 0-5. The top plate 0-2 and the left and right side plates 0-3 are designed into a modular form, namely the top plate and the side plates are divided into a plurality of metal plates, the metal plates are fixed on the structural support 0-1 through bolts, and the number of the installed metal plates is determined according to a field adjustment test result in specific implementation. Two forklift holes 0-6 are respectively reserved at the bottoms of the left side and the right side of the structural support 0-1.

The loop heat pipe precooler 1-1, the evaporator 1-2, the loop heat pipe reheater 1-3 and the supercooling reheating coil 1-4 all adopt finned tube heat exchangers and adopt a metal plate integrated design to form the integrated heat exchanger 1. The integrated heat exchanger is arranged on the front side of the unit, a condensed water collecting tray 2 is arranged below the integrated heat exchanger, and a concentrated water outlet is arranged on the front side of the condensed water collecting tray 2.

The condenser 3 is a microchannel heat exchanger and is horizontally mounted on a bottom bracket. An axial flow fan 3 is arranged above the condenser 3, and the air outlet direction of the fan is downward. An electric heater 8 is installed below the condenser 3 as a supplementary heating means.

The compressor 5 is a vertical scroll compressor and is equipped with a gas-liquid separator 6. The air suction port of the compressor 5 is connected with the gas-liquid separator 6, the air exhaust port is connected with the condenser 3, and the other end of the gas-liquid separator 6 is connected with the evaporator 1-2.

The compressor 5, the gas-liquid separator 6 and the electric box 9 are all arranged at the rear position inside the shell 0 and separated from the air return channel by the intermediate partition boards 0-5.

The throttling element 7 comprises an electronic expansion valve 7-1, a liquid separation head 7-2 and a liquid separation capillary tube, wherein an inlet of the electronic expansion valve 7-1 is connected with an outlet of a refrigerant channel of the supercooling reheating coil 1-4, an outlet of the electronic expansion valve 7-1 is connected with the liquid separation head 7-2, and the liquid separation capillary tube is connected between the liquid separation head 7-2 and the evaporator 1-2.

The loop heat pipe precooler 1-1, the loop heat pipe reheater 1-3 and the water pump 14 are connected in sequence.

The main workflow of this embodiment is as follows:

on the air circulation side: the drying room return air is divided into two paths which respectively enter the first return air channel and the second return air channel. The return air 10 entering the first return air channel is firstly cooled through a loop heat pipe precooler 1-1, then flows through an evaporator 1-2 for cooling and dehumidification, and is heated in two stages through a loop heat pipe reheater 1-3 and a supercooling reheating coil 1-4 in sequence, and the temperature returns to be close to the return air temperature of the drying room. The return air treated in the first return air channel is mixed with the return air 1-2 untreated in the second return air channel, is blown through the condenser 3 under the driving of the fan 4, is heated to high-temperature low-humidity air required by the process, and is finally sent into the drying room 13.

On the refrigerant side: the low-temperature low-pressure refrigerant gas flowing out of the evaporator 1-2 is compressed by a compressor to become high-temperature high-pressure refrigerant gas, then the high-temperature high-pressure refrigerant gas sequentially enters the condenser 3 and the overheating reheating coil 1-4, and is condensed into low-temperature high-pressure refrigerant liquid through heat release to air flowing through the condenser 3 and the overcooling reheating coil 1-4 and is further overcooled. The low-temperature high-pressure refrigerant flowing out of the supercooling reheating coil 1-4 enters the evaporator 1-2 to absorb the heat in the air flowing through the evaporator after being throttled by the throttling element 7, and is evaporated into low-temperature low-pressure refrigerant gas again to complete the refrigerant circulation.

On the loop heat pipe side: the precooler 1-1, the reheater 1-3 and the water pump 14 are communicated with each other, and the internal water circularly flows. The low-temperature water in the precooler 1-1 absorbs heat from the air passing through the precooler 1-1 and is changed into high-temperature water, so that the aim of precooling and cooling the return air is fulfilled. In the reheater 1-3, the high-temperature water releases heat to the air passing through the reheater 1-3 to become low-temperature water, thereby achieving the purpose of reheating and heating the air. The circulation of water between the precooler 1-1 and the reheater 1-2 is driven by a water pump 14.

Example 2

Referring to fig. 5 to 6, the triple-effect heat recovery type air-mixing heat pump drying system in the present embodiment also includes a casing 0, where a loop heat pipe precooler 1-1, an evaporator 1-2, a loop heat pipe reheater 1-3, a supercooling reheating coil 1-4, a water pump 14, a condensed water collecting tray 2, a condenser 3, a fan 4, a compressor 5, a gas-liquid separator 6, a throttling element 7, an electric heater 8, and an electric box 9 are installed inside the casing 0.

Compared with the embodiment 1, the condenser 3 in the embodiment adopts two finned tube heat exchangers which are respectively arranged at the rear positions of the left side and the right side of the unit, and the system air supply is sent out from the left side and the right side. The fan 4 is changed into a volute-free centrifugal fan, meanwhile, the fan 4 is arranged on the middle partition boards 0-5, and holes are formed in the partition boards 0-5 to serve as air inlets of the fan 4.

Further, in order to reduce the volume of the apparatus, the compressor 5 and the gas-liquid separator 6 are installed between the intermediate partition plate and the integrated heat exchanger, and the electric box 9 is installed outside the back plate.

In this embodiment, the functions of the components in the system and the connections between the components are the same as those in embodiment 1, and the workflow of the system is also the same as that in embodiment 1.

The embodiments described above are intended to facilitate the understanding and use of the utility model by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure of the present invention.

Claims

1. The utility model provides a wind formula heat pump drying system is mixed to triple effect heat recovery type which characterized in that, include casing (0) and locate casing (0) in:

the refrigerant circulation comprises evaporators (1-2), a gas-liquid separator (6), a compressor (5), a condenser (3), a supercooling reheating coil (1-4) and a throttling element (7) which are connected in sequence, wherein the throttling element (7) is connected with the evaporators (1-2) to form circulation;

loop heat pipe circulation, which comprises a loop heat pipe precooler (1-1) and a loop heat pipe reheater (1-3) which are connected with each other;

the air cycle comprises a drying room (13), wherein the drying room (13) is connected with an air flow channel of a refrigerant cycle and a loop heat pipe cycle, in the connection sequence of the air flow channel, a loop heat pipe precooler (1-1) is arranged in front of an evaporator (1-2), a loop heat pipe reheater (1-3) is arranged between the evaporator (1-2) and a supercooling coil (1-4), the air output by the drying room (13) is subjected to first heat recovery in the air flow channel of the loop heat pipe cycle, the second heat recovery is carried out in the air flow channel of the evaporator (1-2), and the third heat recovery is carried out in the air flow channel of the supercooling reheating coil (1-4).

2. The drying system of claim 1, wherein water is filled in the loop heat pipe circulation as a medium, and the loop heat pipe circulation further comprises a water pump, so that the water in the loop heat pipe circulation is driven to circulate by the water pump.

3. The drying system of claim 1, wherein the air circulation comprises a first return air channel and a second return air channel, and a fan (4) is disposed in the air circulation, and the fan (4) drives the flow circulation of the return air in the first return air channel and the second return air channel.

4. The drying system of claim 3, wherein in the first return air channel, a return air outlet of the drying room (13) is sequentially connected with an air channel of the loop heat pipe precooler (1-1), an air channel of the evaporator (1-2), an air channel of the loop heat pipe reheater (1-3), an air channel of the supercooling reheating coil (1-4), the fan (14) and an air channel of the condenser (3), and the air channel of the condenser (3) is connected with a return air inlet of the drying room (13).

5. The three-effect heat recovery type air mixing heat pump drying system according to claim 4, wherein in the second return air channel, a return air outlet of the drying room (13) is sequentially connected with an air channel of the fan (14) and the condenser (3), and the air channel of the condenser (3) is connected with a return air inlet of the drying room (13).

6. The drying system of claim 5, wherein the first return air channel and the second return air channel are connected to an air channel inlet of the fan (14), and an air channel outlet of the fan (14) is connected to an air channel inlet of the condenser (3).

7. The drying system of claim 1, wherein the loop heat pipe precooler (1-1), the evaporator (1-2), the loop heat pipe reheater (1-3) and the supercooling reheat coil (1-4) are of an outer metal plate integrated structure.

8. The drying system of claim 7, wherein the loop heat pipe precooler (1-1), the evaporator (1-2), the loop heat pipe reheater (1-3) and the supercooling reheating coil (1-4) form an integrated heat exchanger (1), a condensed water collecting tray (2) is arranged below the integrated heat exchanger, and a centralized water outlet is arranged on one side of the condensed water collecting tray (2).

9. The drying system of claim 1, wherein the casing (0) comprises a structural frame (0-1), a top plate (0-2), left and right side plates (0-3), a back plate (0-4) and a middle partition plate (0-5), the top plate (0-2) and the left and right side plates (0-3) are formed by splicing a plurality of metal plates, and the metal plates are fixed on the structural frame (0-1) through bolts.

10. A three-effect heat recovery type air-mixing heat pump drying system according to claim 3, wherein the condenser (3) is a micro-channel heat exchanger;

the fan (14) is a fixed-frequency axial flow fan;

the compressor (5) is a vertical fixed-frequency scroll compressor;

the throttling element (7) comprises an electronic expansion valve, a liquid separation head and a liquid separation capillary tube which are sequentially connected, wherein the inlet of the electronic expansion valve is connected with the outlet of a refrigerant channel of the supercooling reheating coil (1-4), the outlet of the electronic expansion valve is connected with the liquid separation head, and the liquid separation capillary tube is connected between the liquid separation head and the evaporator.