Air energy and exhaust air stream waste heat complementary multi-mode heat pump drying system

Abstract

The present application belongs to the technical field of material hot air drying, and particularly relates to a multi-mode heat pump drying system with air energy and exhaust air stream waste heat complementation, which mainly comprises a drying chamber, a condenser, a compressor, an exhaust air stream waste heat recovery device, a gas collector, an air source evaporator, a water source evaporator, an exhaust air fan and the like, the air source evaporator and the water source evaporator respectively take outdoor air and water in the exhaust air stream waste heat recovery device as low-temperature heat sources, a temperature difference controller controls opening and closing of an electromagnetic valve on the air source evaporator side and an electromagnetic valve on the water source evaporator side according to a temperature difference between water temperature in the exhaust air stream waste heat recovery device and air temperature at an inlet of the air source evaporator, and the purpose of the present application is to adjust air temperature, relative humidity, oxygen content and CO2 concentration in the drying chamber according to needs, effectively utilize exhaust air stream waste heat, improve drying quality and drying loss of materials, and improve thermal performance and energy utilization efficiency of heat pump hot air drying.

Description

Technical Field

[0001] This invention belongs to the field of hot air drying technology for materials, specifically relating to a multi-mode heat pump drying system that complements air energy and waste heat from exhaust airflow. Background Technology

[0002] Hot air drying of materials is an energy-intensive operation. Energy consumption is even higher when the initial moisture content of the material is high, the required hot air temperature is high, and the amount of water to be removed is large. Air source heat pumps are energy-saving heating devices, but their heating performance is greatly affected by ambient temperature. At low ambient temperatures, the heating temperature of an air source heat pump decreases, its heating power reduces, and its coefficient of performance (COP) decreases.

[0003] High-value agricultural products, such as tobacco leaves, fresh flowers, precious Chinese medicinal herbs, and nuts, have significantly different requirements for drying chamber air temperature, relative humidity, oxygen content, and CO2 concentration at different drying stages. Using a single closed-loop hot air circulation system or a conventional open dehumidification method not only consumes a lot of energy but also makes it difficult to control the oxygen content and CO2 concentration in the drying chamber as needed, thus compromising the quality of the dried materials and resulting in significant drying losses.

[0004] Furthermore, during the drying process, a large amount of high-temperature, high-humidity exhaust airflow is discharged outdoors. Currently, for the recovery and utilization of low-grade waste heat from the exhaust airflow, heat exchangers are mostly used to heat the heat medium to the required temperature using the exhaust airflow, but the heat transfer temperature difference is small. In addition, due to the low thermal conductivity of the exhaust airflow, its heat exchange performance is poor. Therefore, using heat exchangers to heat the heat medium with the exhaust airflow not only results in low waste heat recovery efficiency but also high waste heat recovery costs. This, to some extent, limits the recovery and utilization of waste heat from the exhaust airflow.

[0005] To adjust the air temperature, relative humidity, oxygen content, and CO2 concentration in the drying room as needed, reduce the drying loss of agricultural products, improve their drying quality, and effectively utilize the waste heat of the exhaust airflow to improve the thermal performance and energy efficiency of heat pump hot air drying, seeking new heat pump drying systems has important application value and broad application prospects. Summary of the Invention

[0006] The purpose of this invention is to propose a multi-mode heat pump drying system that complements air energy and waste heat from exhaust airflow. The purpose of this invention is to adjust the air temperature, relative humidity, oxygen content, and CO2 concentration in the drying chamber as needed, effectively utilize the waste heat from exhaust airflow, improve the drying quality of materials and reduce drying losses, while improving the thermal performance and energy utilization efficiency of heat pump hot air drying.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0008] A multi-mode heat pump drying system that complements air source heat pump and exhaust airflow waste heat.

[0009] It includes major components such as a drying chamber, condenser, compressor, exhaust airflow waste heat recovery unit, air collector, air source evaporator, water source evaporator, and exhaust fan. The air source evaporator and water source evaporator use outdoor air and water in the exhaust airflow waste heat recovery unit as low-temperature heat sources, respectively. The temperature difference controller controls the opening and closing of the solenoid valves on the air source evaporator side and the water source evaporator side based on the temperature difference between the water temperature in the exhaust airflow waste heat recovery unit and the air at the inlet of the air source evaporator.

[0010] The drying chamber's air supply outlet is equipped with a condenser, which has a condenser air inlet and a fresh air duct. A fresh air regulating valve is installed on the fresh air duct.

[0011] The condenser is equipped with refrigerant pipes, and the refrigerant pipes are equipped with a compressor, a dehumidifying airflow waste heat recovery unit, a gas collector, an air source evaporator, a water source evaporator, etc., forming a waste heat utilization channel;

[0012] The drying chamber has a return air duct at the return air inlet. The airflow in the return air duct is divided into two paths. One path flows through the return air pipe and the return air regulating valve, and then enters the condenser guide air inlet as needed. After being heated by the condenser, it is sent back into the drying chamber. The other path flows through the exhaust air pipe and the exhaust air volume regulating valve, and then enters the exhaust air waste heat recovery unit as needed. It exchanges heat and moisture with the water in the exhaust air waste heat recovery unit, and then flows through the exhaust pipe and is discharged into the atmosphere.

[0013] The compressor's discharge port is connected to the condenser's refrigerant inlet via a refrigerant pipe, and the condenser's refrigerant outlet is connected to the distributor's inlet via a refrigerant pipe. The high-temperature, high-pressure refrigerant vapor, compressed by the compressor, exchanges heat with air from the condenser's air inlet in the condenser, releasing heat and condensing into liquid refrigerant. The heated air is then sent into the drying chamber through the drying chamber's air outlet. The refrigerant flowing from the condenser's outlet enters the distributor, where it splits into two streams. One stream flows through the air-source evaporator's side expansion valve and then into the air-source evaporator's refrigerant inlet, absorbing heat from the outdoor air and evaporating. It then flows through the air-source evaporator's side solenoid valve and into the gas collector. Another path flows through the throttle valve on the water source evaporator side and enters the refrigerant inlet of the water source evaporator. It absorbs heat from the water in the dehumidification waste heat recovery unit and evaporates. Then it flows through the solenoid valve on the water source evaporator side and enters the gas collector. A circulating water pipe is installed between the water source evaporator and the dehumidification waste heat recovery unit. A circulating water pump is installed on the circulating water pipe. The refrigerant vapor collected by the gas collector enters the compressor for compression and is discharged from the compressor's exhaust port.

[0014] Hot air entering the drying chamber exchanges heat and moisture with the material, resulting in a decrease in temperature and an increase in humidity (moisture content), before exiting from the return air vent. Based on the drying process requirements for temperature, relative humidity, oxygen content, and CO2 concentration in the drying chamber, the openings of the exhaust air volume regulating valve, return air regulating valve, and fresh air regulating valve are adjusted as needed to regulate the exhaust air volume, return air volume, and fresh air volume, meeting the baking process requirements to improve the drying quality of the material and reduce drying losses. The airflow exiting the return air vent of the drying chamber is divided into two paths. One path flows through the return air duct and the return air regulating valve, then enters the condenser guide air inlet as needed, where it is heated by the condenser and then sent back into the drying chamber. The other path flows through the exhaust air duct and the exhaust air volume regulating valve, then enters the exhaust waste heat recovery unit as needed, where it exchanges heat and moisture with the water in the unit, releasing heat and reducing moisture content, before flowing through the exhaust pipe and being discharged into the atmosphere. Outdoor fresh air, drawn by the exhaust fan, flows through the fresh air duct and regulating valve, entering the condenser inlet as needed. After being heated by the condenser, it is then sent back into the drying chamber. The water in the exhaust heat recovery unit is heated by the exhaust airflow, increasing its temperature. Driven by the circulating water pump, the water flows through the circulating pipe to the water-side inlet of the water source evaporator, where it exchanges heat with the refrigerant, releasing heat and decreasing its temperature. It then flows out from the water-side outlet of the water source evaporator, returning to the exhaust heat recovery unit to be heated again by the exhaust airflow.

[0015] A water temperature sensor is placed in the water of the dehumidification waste heat recovery unit to monitor the water temperature in real time. An ambient temperature sensor is placed at the air inlet of the air source evaporator to monitor the air temperature at the air inlet in real time. A temperature difference controller controls the opening and closing of the solenoid valves on both the air source evaporator and water source evaporator sides based on the real-time monitored water and air temperatures at the air inlet of the air source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is higher than a set value of 1 (e.g., 4℃), the solenoid valve on the air source evaporator side closes, and the solenoid valve on the water source evaporator side opens, operating in a single-operation mode for the water source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is lower than a set value of 2 (e.g., -1℃), the solenoid valve on the air source evaporator side opens, and the solenoid valve on the water source evaporator side closes, operating in a single-operation mode for the air source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is lower than set value 1 (e.g., 4℃) and higher than set value 2 (e.g., -1℃), both the solenoid valves on the air source evaporator side and the water source evaporator side open, operating in parallel with the water source evaporator. In this way, by selecting the evaporator operating mode, the evaporation temperature can be effectively increased, and the dehumidification waste heat and air energy complement each other to provide a low-temperature heat source for the evaporator, thereby improving the heat pump's coefficient of performance (COP), heating power, and reducing compressor power consumption.

[0016] Furthermore, an overflow pipe is installed on the exhaust airflow waste heat recovery unit.

[0017] Furthermore, a drain pipe is installed at the bottom of the dehumidification airflow waste heat recovery unit, and a drain valve is installed on the drain pipe.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] On the one hand, the exhaust air volume, return air volume, and fresh air volume are adjusted as needed according to the drying process to improve the drying quality of materials and reduce drying losses. On the other hand, the waste heat of the exhaust airflow is effectively recovered, and the evaporator operating mode is selected based on the temperature difference between the water in the exhaust waste heat recovery unit and the air at the air inlet of the air source evaporator. This effectively improves the heat pump's coefficient of performance (COP) and heating power, and reduces the compressor's power consumption. The multi-mode pump drying system that integrates air energy and exhaust waste heat, as described in this invention, has advantages such as reduced losses, improved quality and efficiency, and high energy saving. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the composition of the multi-mode heat pump drying system of the present invention, which complements the air energy and the waste heat of the dehumidifying airflow.

[0021] Figure 1 The numbers in the diagram represent the following in order: 1-Drying chamber, 2-Drying chamber air outlet, 3-Condenser, 4-Compressor, 5-Refrigerant pipe, 6-Exhaust pipe, 7-Dehumidification airflow waste heat recovery unit, 8-Overflow pipe, 9-Dehumidification duct, 10-Temperature difference controller, 11-Water temperature sensor, 12-Gas collector, 13-Ambient temperature sensor, 14-Drain pipe, 15-Drain valve, 16-Solenoid valve on the water source evaporator side, 17-Air source evaporator... 18-Evaporator-side solenoid valve, 19-Air-source evaporator, 20-Circulating water pump, 21-Circulating water pipe, 22-Water-source evaporator-side throttle valve, 23-Air-source-side throttle valve, 24-Exhaust fan, 25-Exhaust air volume regulating valve, 26-Dispenser, 27-Return air regulating valve, 28-Return air duct, 29-Fresh air regulating valve, 30-Fresh air duct, 31-Condenser guide air inlet, 32-Drying chamber return air inlet. Detailed Implementation

[0022] like Figure 1 As shown, to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0023] A multi-mode heat pump drying system that complements air source heat pump and exhaust airflow waste heat.

[0024] It includes major components such as drying chamber 1, condenser 3, compressor 4, exhaust airflow waste heat recovery unit 7, air collector 12, air source evaporator 18, water source evaporator 19, and exhaust fan 24.

[0025] The drying chamber 1 has a condenser 3 installed at its air outlet 2. The condenser 3 has a condenser air inlet 31 and a fresh air duct 30 installed on it. The fresh air duct 30 is equipped with a fresh air regulating valve 29.

[0026] The condenser 3 is equipped with a refrigerant pipe 5, and the refrigerant pipe 5 is equipped with a compressor 4, a dehumidifying airflow waste heat recovery device 7, a gas collector 12, an air source evaporator 18, a water source evaporator 19, etc., forming a waste heat utilization channel.

[0027] The drying chamber 1 has a return air duct on the return air inlet 32. The airflow in the return air duct is divided into two paths. One path flows through the return air pipe 28 and the return air regulating valve 27, and then enters the condenser guide air inlet 31 as needed. After being heated by the condenser 3, it is sent back into the drying chamber 1. The other path flows through the exhaust air pipe 9 and the exhaust air volume regulating valve 25, and then enters the exhaust air waste heat recovery unit 7 as needed. It exchanges heat and moisture with the water in the exhaust air waste heat recovery unit 7, and then flows through the exhaust pipe 6 to be discharged into the atmosphere.

[0028] The discharge port of compressor 4 is connected to the refrigerant inlet of condenser 3 via refrigerant pipe 5, and the refrigerant outlet of condenser 3 is connected to the inlet of distributor 26 via refrigerant pipe 5. The high-temperature, high-pressure refrigerant vapor compressed by compressor 4 exchanges heat with air from condenser guide air inlet 31 in condenser 3, releasing heat and condensing into liquid refrigerant. The heated air is then sent into the drying chamber through drying chamber air outlet 2. The refrigerant flowing out of the refrigerant outlet of condenser 3 enters distributor 26, and is divided into two streams. One stream flows through the air source evaporator side throttle valve 23 and enters the refrigerant inlet of air source evaporator 18, absorbing heat from the outdoor air and evaporating. It then flows through the air source evaporator side solenoid valve 17 and enters the air collector 12. Another path flows through the throttle valve 22 on the water source evaporator side and enters the refrigerant inlet of the water source evaporator 19. It absorbs heat from the water in the dehumidification waste heat recovery unit 7 and evaporates. Then it flows through the solenoid valve 16 on the water source evaporator side and enters the gas collector 12. A circulating water pipe 21 is provided between the water source evaporator 19 and the dehumidification waste heat recovery unit 7. A circulating water pump 20 is provided on the circulating water pipe 21. The refrigerant vapor collected by the gas collector 12 enters the compressor 4 for compression and is discharged from the exhaust port of the compressor 4.

[0029] Hot air supplied to drying chamber 1 exchanges heat and moisture with the material, resulting in a decrease in temperature and an increase in humidity (moisture content), before exiting from the return air vent 32. Based on the drying process requirements for temperature, relative humidity, oxygen content, and CO2 concentration in drying chamber 1, the openings of the exhaust air volume regulating valve 25, return air regulating valve 27, and fresh air regulating valve 29 are adjusted as needed to regulate the exhaust air volume, return air volume, and fresh air volume, meeting the baking process requirements to improve the drying quality of the material and reduce drying losses. The airflow exiting from the return air vent 32 of the drying chamber is divided into two paths. One path flows through return air duct 28 and return air regulating valve 27, then enters the condenser guide air inlet 31 as needed, where it is heated by the condenser 3 and then sent back into drying chamber 1. The other path flows through exhaust air duct 9 and exhaust air volume regulating valve 25, then enters the exhaust waste heat recovery unit 7 as needed, where it exchanges heat and moisture with the water in the exhaust waste heat recovery unit 7, releasing heat and reducing moisture content, before flowing through exhaust pipe 6 and being discharged into the atmosphere. Outdoor fresh air, drawn by the dehumidifying fan 24, flows through the fresh air duct 30 and the fresh air regulating valve 29, entering the condenser guide air inlet 31 as needed. After being heated by the condenser 3, it is sent back into the drying chamber 1. The water in the dehumidifying waste heat recovery unit 7 is heated by the dehumidifying airflow, raising its temperature. Under the action of the circulating water pump 20, it enters the inlet on the water side of the water source evaporator 19 through the circulating water pipe 21, exchanges heat with the refrigerant, releases heat, lowers its temperature, and flows out from the outlet on the water side of the water source evaporator 19, returning to the dehumidifying waste heat recovery unit 7 to be heated again by the dehumidifying airflow.

[0030] A water temperature sensor 11 is placed in the water of the dehumidification waste heat recovery unit 7 to detect the water temperature in the dehumidification waste heat recovery unit 7 in real time. An ambient temperature sensor 13 is placed at the air inlet of the air source evaporator 18 to detect the air temperature at the air inlet of the air source evaporator 18 in real time. The temperature difference controller 10 controls the opening and closing of the solenoid valve 17 on the air source evaporator side and the solenoid valve 16 on the water source evaporator side based on the real-time detected water temperature in the dehumidification waste heat recovery unit 7 and the air temperature at the air inlet of the air source evaporator 18. When the temperature difference between the water in the dehumidification waste heat recovery unit 7 and the air at the air inlet of the air source evaporator 18 is higher than a set value of 1 (e.g., 4℃), the solenoid valve 17 on the air source evaporator side closes and the solenoid valve 16 on the water source evaporator side opens, operating in a single working mode for the water source evaporator 19. When the temperature difference between the water in the dehumidification waste heat recovery unit 7 and the air at the air inlet of the air source evaporator is lower than a set value 2 (e.g., -1℃), the solenoid valve 17 on the air source evaporator side opens, and the solenoid valve 16 on the water source evaporator side closes, operating in a single-operation mode for the air source evaporator 18. When the temperature difference between the water in the dehumidification waste heat recovery unit 7 and the air at the air inlet of the air source evaporator is lower than a set value 1 (e.g., 4℃) or higher than a set value 2 (e.g., -1℃), both the solenoid valve 17 on the air source evaporator side and the solenoid valve 16 on the water source evaporator side open, operating in a parallel mode for the water source evaporator 19 and the air source evaporator 18. In this way, by selecting the evaporator operating mode, the evaporation temperature can be effectively increased, and the dehumidification waste heat and air energy complement each other to provide a low-temperature heat source for the evaporator, thereby improving the heat pump's coefficient of performance, heating power, and reducing the compressor's power consumption.

[0031] A better option is to install an overflow pipe on the dehumidification airflow waste heat recovery unit for easy overflow.

[0032] A better option is to provide a drain pipe 14 at the bottom of the dehumidification airflow waste heat recovery unit 7, and a drain valve 15 on the drain pipe 14 for convenient drainage.

[0033] The working principle of this invention is as follows:

[0034] This invention includes a dehumidification airflow regulating valve, a return air regulating valve, and a fresh air regulating valve. Based on the drying process requirements for drying chamber temperature, relative humidity, oxygen content, and CO2 concentration, the opening of these valves is adjusted. The system can operate in 100% fresh air, 100% return air, or a proportional mixture of fresh and return air modes to improve material drying quality and reduce drying losses. A dehumidification waste heat recovery unit, using water as the heat transfer medium, recovers waste heat from the dehumidification airflow to increase the evaporation temperature of the water source evaporator, thereby improving its performance. A water source evaporator and an air source evaporator are included, each using outdoor air and water from the dehumidification waste heat recovery unit as low-temperature heat sources, respectively. A temperature difference controller is installed, controlling the operation of the air source evaporator and water source evaporator based on the water temperature in the dehumidification waste heat recovery unit and the air temperature at the inlet of the air source evaporator, detected by temperature sensors. These evaporators can operate individually or in parallel to improve the thermal performance and energy utilization efficiency of the heat pump.

[0035] The multi-mode heat pump drying system, which combines air source heat pump with exhaust airflow waste heat, consists of a compressor, condenser, throttling valve, air source evaporator, water source evaporator, exhaust waste heat recovery unit, temperature difference controller, circulating water pump, exhaust airflow regulating valve, return air regulating valve, fresh air regulating valve, exhaust fan, drying chamber, drying chamber air outlet, refrigerant pipe, exhaust pipe, overflow pipe, exhaust air duct, water temperature sensor, air collection pipe, ambient temperature sensor, drain pipe, drain valve, solenoid valve, circulating water pipe, distributor, return air duct, fresh air duct, condenser air inlet guide, and drying chamber return air outlet, among other main components.

[0036] The compressor's discharge port is connected to the condenser's refrigerant inlet via a refrigerant pipe, and the condenser's refrigerant outlet is connected to the distributor's inlet via a refrigerant pipe. The high-temperature, high-pressure refrigerant vapor, compressed by the compressor, exchanges heat with air from the condenser's air inlet in the condenser, releasing heat and condensing into liquid refrigerant. The heated air is then sent into the drying chamber through the drying chamber's air outlet. The refrigerant flowing from the condenser's outlet enters the distributor, where it is split into two streams. One stream flows through a throttling valve and enters the refrigerant inlet of the air-source evaporator, absorbing heat from the outdoor air and evaporating. It then flows through the solenoid valve on the air-source evaporator side into the gas collector. Another refrigerant flow passes through a throttling valve and enters the refrigerant inlet of the water source evaporator. It absorbs heat from the water in the dehumidification waste heat recovery unit and evaporates. Then, it flows through the solenoid valve on the water source evaporator side and enters the gas collector. A circulating water pipe is installed between the water source evaporator and the dehumidification waste heat recovery unit, and a circulating water pump is installed on the circulating water pipe. The refrigerant vapor collected by the gas collector enters the compressor for compression and is discharged from the compressor's exhaust port.

[0037] Hot air supplied to the drying chamber exchanges heat and moisture with the material, resulting in a decrease in temperature and an increase in moisture content, before exiting from the return air vent. Based on the drying process requirements for temperature, relative humidity, oxygen content, and CO2 concentration in the drying chamber, the openings of the exhaust air volume regulating valve, return air regulating valve, and fresh air regulating valve are adjusted as needed to regulate the exhaust air volume, return air volume, and fresh air volume, meeting the baking process requirements to improve the drying quality of the material and reduce drying losses. The airflow exiting the drying chamber's return air vent is divided into two paths. One path flows through the return air duct and the return air regulating valve, then enters the condenser's guide air inlet as needed, where it is heated by the condenser and then sent back into the drying chamber. The other path flows through the exhaust air duct and the exhaust air volume regulating valve, then enters the exhaust waste heat recovery unit as needed, where it exchanges heat and moisture with the water in the unit, releasing heat and reducing moisture content, before finally flowing through the exhaust pipe and being discharged into the atmosphere. Outdoor fresh air, drawn by the exhaust fan, flows through the fresh air duct and the fresh air regulating valve, and enters the condenser air inlet as needed. After being heated by the condenser, it is sent back into the drying chamber.

[0038] The water in the dehumidification waste heat recovery unit is heated by the dehumidification airflow, causing its temperature to rise. Under the action of the circulating water pump, the water enters the inlet on the water side of the water source evaporator through the circulating water pipe, where it exchanges heat with the refrigerant, releases heat, and its temperature decreases. It then flows out from the outlet on the water side of the water source evaporator and returns to the dehumidification waste heat recovery unit to be heated again by the dehumidification airflow.

[0039] A water temperature sensor is placed in the water of the dehumidification waste heat recovery unit to monitor the water temperature in real time. An ambient temperature sensor is placed at the air inlet of the air source evaporator to monitor the air temperature at the air inlet in real time. A temperature difference controller controls the opening and closing of the solenoid valves on both the air source evaporator and water source evaporator sides based on the real-time monitored water and air temperatures at the air inlet of the air source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is higher than a set value of 1, the solenoid valve on the air source evaporator side closes, and the solenoid valve on the water source evaporator side opens, operating in a single-operation mode for the water source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is lower than a set value of 2, the solenoid valve on the air source evaporator side opens, and the solenoid valve on the water source evaporator side closes, operating in a single-operation mode for the air source evaporator. When the temperature difference between the water in the dehumidification waste heat recovery unit and the air at the air inlet of the air source evaporator is lower than set value 1 and higher than set value 2, the solenoid valves on both the air source evaporator and water source evaporator sides open, operating in parallel with the water source evaporator. By selecting the evaporator operating mode, the evaporation temperature is effectively increased, and the dehumidification waste heat and air energy complement each other to provide a low-temperature heat source for the evaporator, thereby improving the heat pump's coefficient of performance (COP), heating power, and reducing compressor power consumption.

[0040] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-mode heat pump drying system complementary to air energy and exhaust air stream waste heat, characterized in that: it comprises a drying chamber (1), a condenser (3), a compressor (4), an exhaust air stream waste heat recovery device (7), a gas collector (12), an air source evaporator (18), a water source evaporator (19), and an exhaust fan (24); the drying chamber air outlet (2) of the drying chamber (1) is provided with the condenser (3), the condenser (3) is provided with a condenser air inlet guide (31), and the condenser (3) is provided with a fresh air pipe (30); the fresh air pipe (30) is provided with a fresh air regulating valve (29); the condenser (3) is provided with a refrigerant pipeline (5); the refrigerant pipeline (5) is provided with the compressor (4), the exhaust air stream waste heat recovery device (7), the gas collector (12), the air source evaporator (18), and the water source evaporator (19) to form a waste heat utilization channel; the drying chamber air return port (32) of the drying chamber (1) is provided with a return air channel; the return air channel is divided into two paths; one path flows through the return air regulating valve (27) through the return air pipe (28) and enters the condenser air inlet guide (31) as needed; the air is heated by the condenser (3) and then sent into the drying chamber (1) again; the other path flows through the exhaust air volume regulating valve (25) through the exhaust air pipe (9) and enters the exhaust air stream waste heat recovery device (7) as needed; the air exchanges heat and humidity with the water in the exhaust air stream waste heat recovery device (7); and then the air is discharged into the atmosphere through the exhaust pipe (6); the exhaust port of the compressor (4) is connected to the refrigerant inlet of the condenser (3) through the refrigerant pipeline (5); the refrigerant outlet of the condenser (3) is connected to the inlet of the distributor (26) through the refrigerant pipeline (5); the high-temperature and high-pressure refrigerant vapor compressed by the compressor (4) exchanges heat with the air from the condenser air inlet guide (31) in the condenser (3), releases heat, and condenses into liquid refrigerant; and the air is heated and sent into the drying chamber through the drying chamber air outlet (2); the refrigerant flowing out of the refrigerant outlet of the condenser (3) enters the distributor (26); the refrigerant is divided into two paths in the distributor (26); one path enters the refrigerant inlet of the air source evaporator (18) after flowing through the air source evaporator side throttling valve (23); the air absorbs heat from outdoor air and evaporates; and then the air enters the gas collector (12) after flowing through the air source evaporator side electromagnetic valve (17); the other path enters the refrigerant inlet of the water source evaporator (19) after flowing through the water source evaporator side throttling valve (22); the air absorbs heat from the water in the exhaust air stream waste heat recovery device (7) and evaporates; and then the air enters the gas collector (12) after flowing through the water source evaporator side electromagnetic valve (16); the circulation water pipe (21) is arranged between the water source evaporator (19) and the exhaust air stream waste heat recovery device (7); the circulation water pump (20) is arranged on the circulation water pipe (21); and the refrigerant vapor collected by the gas collector (12) enters the compressor (4) for compression and is discharged from the exhaust port of the compressor (4). ​ ​ ​ The water temperature sensor (11) is arranged in the exhaust air stream waste heat recovery device (7), the ambient temperature sensor (13) is arranged at the air inlet position of the air source evaporator (18), and the water temperature sensor (11), the ambient temperature sensor (13), the air source evaporator side electromagnetic valve (17) and the water source evaporator side electromagnetic valve (16) are connected with the temperature difference controller (10).

2. The multi-mode heat pump drying system with air energy and exhaust air stream waste heat complementary according to claim 1, characterized in that: The overflow pipe (8) is arranged on the exhaust air stream waste heat recovery device (7).

3. The multi-mode heat pump drying system with air energy and exhaust air stream residual heat complementation according to claim 1, characterized in that: The blowdown pipe (14) is arranged at the bottom of the exhaust air stream waste heat recovery device (7), and the blowdown valve (15) is arranged on the blowdown pipe (14).

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