A temperature and humidity independent control's tobacco curing barn heating system
By coupling the solution absorption dehumidification cycle with the heat pump heating cycle, independent temperature and humidity control is achieved, solving the problems of high energy consumption and pollution emissions of existing drying equipment. This results in a highly efficient, energy-saving, and environmentally friendly drying room heating system, which improves product quality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING UNIV OF SCI & TECH
- Filing Date
- 2026-03-20
- Publication Date
- 2026-05-29
AI Technical Summary
Existing drying equipment has high energy consumption and serious pollution emissions. Traditional dense drying rooms are difficult to recover the waste heat from moisture removal. Heat pump drying rooms require electric heating to supplement the drying of high-moisture materials, which leads to increased power consumption.
By coupling the solution absorption dehumidification cycle with the heat pump heating cycle, independent temperature and humidity control is achieved. A closed-loop system is adopted, eliminating the exhaust port and recovering the waste heat of the regenerated humid air. The combination of the heat pump and the solution absorption dehumidification cycle allows for independent control of temperature and humidity.
It achieves efficient, energy-saving, and environmentally friendly temperature and humidity control, reduces power consumption, improves product quality, reduces the need for supplemental electric heating, and the system equipment is mature and easy to promote.
Smart Images
Figure CN122107718A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a drying room heating system with independent temperature and humidity control, belonging to the technical field of drying and processing of agricultural and sideline products, tobacco, Chinese medicinal materials, aquatic products and forest products. Background Technology
[0002] my country is rich in agricultural resources, and there is a widespread demand for drying and processing of these products. Existing drying equipment is diverse, including electric heating, heat pumps, steam, natural gas, coal, liquefied petroleum gas, and biomass fuels, but all generally suffer from high energy consumption and pollution. Especially during the initial curing of tobacco, traditional dense curing barns suffer from significant heat loss due to residual heat during dehumidification, making heat recovery difficult. While heat pump curing barns, promoted in recent years, have shown some energy-saving effects, they still require supplemental electric heating during the "color-setting period" and "drying period," leading to increased electricity consumption and operating costs. Therefore, there is an urgent need to develop a new type of heating system that is highly efficient, energy-saving, environmentally friendly, and suitable for drying high-moisture materials. This invention couples a solution absorption dehumidification cycle with a heat pump heating cycle, achieving independent temperature and humidity control, effectively solving the aforementioned problems. Summary of the Invention
[0003] The purpose of this invention is to provide a heating system for a drying room with independent temperature and humidity control, which has advantages such as energy saving, environmental protection, low operating costs, and high product quality. This invention is achieved through the following technical solution.
[0004] A heating system for a drying oven with independent temperature and humidity control, wherein the heating system is a combined heat pump system; the heating system consists of three parts: a heat pump heating cycle, a solution absorption dehumidification cycle, and a drying oven air circulation cycle. The heating system includes a heat pump compressor 1, a drying oven circulating fan 2, an air heater 3, a drying oven dehumidification spray tower 4, a dilute solution pump 5, a dilute solution heater I6, a concentrated solution cooler 7, a solution regeneration spray chamber 8, a concentrated solution pump 9, a pressurizing fan 10, a heat pump evaporator 11, a thermal expansion valve I12, a drying filter I13, a solenoid valve 14, a liquid storage tank I15, and a thermal expansion valve II16. In the heat pump heating cycle, the high-temperature and high-pressure working fluid outlet of the heat pump compressor 1 is divided into two paths. One path is connected to the inlet of the dilute solution heater I6, and the other path is connected to the inlet of the air heater 3. The working fluid outlets of the dilute solution heater 6 and the air heater 3 are connected to the storage tank I15. The working fluid outlet of the storage tank I15 passes through the solenoid valve 14 and the dryer filter I13 in sequence and then splits into two paths. One path passes through the thermal expansion valve I12 and enters the heat pump evaporator 11 and then enters the main suction port of the heat pump compressor 1. The other path passes through the thermal expansion valve II16 and connects to the concentrated solution cooler 7 in sequence and then connects to the air replenishment port of the heat pump compressor 1. In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower 4 of the drying room is sent to the dilute solution heater I6 by the dilute solution pump 5 and then enters the solution regeneration spray chamber 8. The regenerated concentrated solution outlet in the solution regeneration spray chamber 8 is cooled by the concentrated solution pump 9 and the concentrated solution cooler 7 in sequence and then returned to the top of the dehumidification spray tower 4. In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower 4 through the return air inlet, then enters the air heater 3, and finally is sent back to the drying room through the drying room circulation fan 2. During the heat pump heating cycle and solution absorption dehumidification cycle, outdoor air flows sequentially through the solution regeneration spray chamber 8 and the pressurized fan 10 before entering the heat pump evaporator 11 and finally being discharged.
[0005] The heat pump compressor 1 is a screw or scroll compressor with an intermediate gas inlet.
[0006] The low-pressure refrigerant vapor from the outlet of the concentrated solution cooler 7 is fed into the gas supply port of the heat pump compressor 1.
[0007] The dilute solution is an aqueous solution of lithium bromide, lithium chloride, calcium chloride, magnesium chloride, triethylene glycol, potassium / sodium formate, potassium / sodium acetate, or an ionic liquid, or a mixed aqueous solution composed of two or more of the above hygroscopic agents in any ratio.
[0008] A heating system for a drying oven with independent temperature and humidity control, wherein the heating system is a separate heat pump system; the heating system consists of four parts: a heat pump heating cycle, a solution absorption dehumidification cycle, a drying oven air circulation, and a dilute solution heating heat pump heating cycle. The heating system includes a heat pump compressor 1, a drying oven circulating fan 2, an air heater 3, a drying oven dehumidification spray tower 4, a dilute solution pump 5, a concentrated solution cooler 7, a solution regeneration spray chamber 8, a concentrated solution pump 9, a pressurizing fan 10, a heat pump evaporator 11, a thermal expansion valve I12, a drying filter I13, a solenoid valve I14, a liquid storage tank I15, a thermal expansion valve II16, a dilute solution heater II17, a solution regeneration heat pump compressor 18 with a gas inlet 19, a solution regeneration heat pump evaporator 19, a thermal expansion valve II20, a drying filter 21, a solenoid valve II22, and a liquid storage tank II23; In the heat pump heating cycle, the high-temperature and high-pressure working fluid outlet of the heat pump compressor 1 is connected to the inlet of the air heater 3, and the working fluid outlet of the air heater 3 is connected to the liquid storage tank I15. The working fluid outlet of the liquid storage tank 15 passes through the solenoid valve 14 and the dryer filter I13 in sequence, and then enters the heat pump evaporator 11 through the thermal expansion valve I12 before entering the heat pump compressor 1. In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower 4 of the drying room is sent to the dilute solution heater II17 through the dilute solution pump 5 for heating and then enters the solution regeneration spray chamber 8. The regenerated concentrated solution outlet in the solution regeneration spray chamber 8 is cooled by the concentrated solution pump 9 and the concentrated solution cooler 7 in sequence and then returns to the top of the dehumidification spray tower 4. In the dilute solution heating heat pump heating cycle, the outlet of the solution regeneration heat pump compressor 18 with a gas inlet is connected to the dilute solution heater II17, and then sequentially connected to the liquid storage tank II23, the solenoid valve II22, and the dryer filter II21. The outlet of the dryer filter II21 is divided into two paths. One path is sequentially connected to the thermal expansion valve II16 and the concentrated solution cooler 7, and then returns to the gas inlet of the solution regeneration heat pump compressor 18 with a gas inlet. The other path passes through the thermal expansion valve II20 and connects to the solution regeneration heat pump evaporator 19, and finally enters the main suction port of the solution regeneration heat pump compressor 18 with a gas inlet. In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower 4 through the return air inlet, then enters the air heater 3, and finally is sent back to the drying room through the drying room circulation fan 2.
[0009] The heating system for the drying room with independent temperature and humidity control, when the heating system is a combined heat pump system, operates on the following principle: (I) Working principle of the heat pump circulation system: The high-temperature and high-pressure superheated steam discharged from the heat pump compressor 1 is divided into two paths, which enter the subsequent equipment through the flow regulating valves respectively. The first path enters the air heater 3 (i.e., the heat pump condenser) to heat the circulating air in the drying room. After the working fluid releases heat, it condenses into a high-pressure liquid and flows into the liquid storage tank I15. The second path enters the dilute solution heater I6, where it condenses and releases heat. It then merges with the first path in the form of a high-pressure liquid and enters the liquid storage tank I15. The high-pressure liquid working fluid flowing from the storage tank I15 flows sequentially through the solenoid valve I14 and the dryer filter I13 for dehydration and impurity removal. It then splits into two paths: one path is throttled and depressurized by the thermal expansion valve I12, forming a low-temperature, low-pressure working fluid liquid (containing a small amount of flash vapor), which enters the heat pump evaporator 11. After absorbing heat from the humid air in the solution regeneration spray chamber 8, it completely evaporates into low-pressure steam and returns to the main suction port of the heat pump compressor 1. The other path is throttled and depressurized by the thermal expansion valve II16, entering the concentrated solution cooler 7. After absorbing heat from the concentrated solution, it completely evaporates into low-pressure steam and returns to the air supply port of the heat pump compressor 1. Both working fluids are compressed by the compressor to form high-temperature, high-pressure superheated steam again, completing one heat pump cycle.
[0010] (II) Working Principle of Solution Absorption Dehumidification Circulation System: The dilute solution flowing from the bottom of the dehumidification spray tower 4 in the drying oven is pressurized by the dilute solution pump 5 and sent to the dilute solution heater I6. It absorbs heat from the high-temperature, high-pressure working fluid vapor and heats up, then enters the distribution pipe of the solution regeneration spray chamber 8 and is sprayed through nozzles. Inside the solution regeneration spray chamber 8, the dilute solution exchanges heat and moisture with the outdoor air. After the water evaporates, it is concentrated into a concentrated solution, which is collected in the bottom sump. The concentrated solution is then pumped by the concentrated solution pump 9 to the concentrated solution cooler 7, where it is cooled by a low-temperature refrigerant to reduce its vapor pressure and enhance its dehumidification capacity. The cooled concentrated solution enters the distribution pipe at the top of the dehumidification spray tower 4 in the drying oven and is evenly sprayed onto the surface of the packing material. It exchanges heat and mass with the humid air from the drying oven, absorbing water vapor from the air and becoming a dilute solution, which is then collected in the bottom sump, completing one solution dehumidification cycle.
[0011] (III) Working principle of the humid air circulation system in the drying room: After being filtered through the return air inlet, the humid air enters the closed space where the dehumidification spray tower 4 is located. It enters the dehumidification spray tower 4 through the air inlets around the tower for drying treatment. The dehydrated air enters the air heater (heat pump condenser) 3 for heating, and then is sent back to the drying room for heating through the circulating fan, forming a drying room air circulation process.
[0012] (iv) Outdoor air flow: Outdoor air first flows through the solution regeneration spray chamber 8 to absorb heat and moisture, forming hot and humid air, and then is sent to the heat pump evaporator 11 by the pressurized fan 10 to exchange heat with the low-temperature working fluid in the pipe, so as to realize the effective recovery and utilization of the waste heat of the hot and humid air.
[0013] The heating system for the drying room with independent temperature and humidity control, when the heating system is a separate heat pump system, operates on the following principle: (I) Working principle of the heat pump cycle system: The high-temperature and high-pressure superheated steam discharged from the heat pump compressor 1 enters the air heater 3 (i.e., the heat pump condenser) to heat the circulating air in the drying room. After the working fluid releases heat, it condenses into a high-pressure liquid and flows into the storage tank I15. The high-pressure liquid working fluid flowing out of the storage tank I15 flows through the solenoid valve I14 and the dryer filter I13 in sequence for dehydration and impurity removal. Then, it passes through the thermal expansion valve I12 for throttling, pressure reduction and temperature reduction, forming a low-temperature and low-pressure working fluid liquid (containing a small amount of flash vapor). It enters the heat pump evaporator 11, absorbs heat from the humid and hot air in the solution regeneration spray chamber 8, and completely evaporates into low-pressure steam, returning to the heat pump compressor 1 to complete one heat pump cycle.
[0014] (II) Working Principle of Solution Absorption Dehumidification Circulation System: The dilute solution flowing from the bottom of the dehumidification spray tower 4 in the drying oven is pressurized by the dilute solution pump 5 and sent to the heater II17. It absorbs heat from the high-temperature, high-pressure working fluid vapor and heats up, then enters the distribution pipe of the solution regeneration spray chamber 8 and is sprayed through nozzles. Inside the solution regeneration spray chamber 8, the dilute solution exchanges heat and moisture with the outdoor air. After the moisture evaporates, it is concentrated into a concentrated solution, which is collected in the bottom sump. The concentrated solution is then pumped by the concentrated solution pump 9 to the concentrated solution cooler 7, where it is cooled by a low-temperature refrigerant to reduce its vapor pressure and enhance its dehumidification capacity. The cooled concentrated solution enters the distribution pipe at the top of the dehumidification spray tower 4 in the drying oven and is evenly sprayed onto the packing surface. It exchanges heat and mass with the humid air from the drying oven, absorbing water vapor from the air and becoming a dilute solution, which is then collected in the bottom sump, completing one solution dehumidification cycle.
[0015] (III) Working principle of the humid air circulation system in the drying room: After being filtered through the return air inlet, the humid air enters the closed space where the dehumidification spray tower 4 is located. It enters the dehumidification spray tower 4 through the air inlets around the tower for drying treatment. The dehydrated air enters the air heater (heat pump condenser) 3 for heating, and then is sent back to the drying room for heating through the circulating fan, forming a drying room air circulation process.
[0016] (iv) The working principle of the dilute solution heating heat pump heating cycle is as follows: The high-temperature and high-pressure superheated steam from the outlet of the solution regeneration heat pump compressor 18 with a gas inlet enters the dilute solution heater II17 to heat the dilute solution and increase the water vapor pressure on the solution surface. After the superheated steam condenses, it enters the storage tank II23 for storage. The high-pressure liquid working fluid flowing out of the storage tank II23 flows through the solenoid valve II22 and the dryer filter II21 in sequence, and then splits into two paths. One path is connected to the thermal expansion valve II16 in sequence to reduce pressure and temperature, forming a low-temperature and low-pressure working fluid liquid (containing a small amount of flash vapor), which enters the concentrated solution cooler 7 and then returns to the gas inlet of the solution regeneration heat pump compressor 18 with a gas inlet; the other path is throttled and cooled by the thermal expansion valve II20 to form a low-temperature and low-pressure working fluid liquid (containing a small amount of flash vapor), which enters the regeneration heat pump evaporator 19, absorbs heat from the outside air and evaporates completely into low-pressure steam, and finally enters the main suction port of the solution regeneration heat pump compressor 18 with a gas inlet.
[0017] (v) Outdoor air flow: Outdoor air first flows through the solution regeneration spray chamber 8 to absorb heat and moisture, forming hot and humid air, and then is sent to the heat pump evaporator 11 by the pressurized fan 10 to exchange heat with the low-temperature working fluid in the pipe, so as to realize the effective recovery and utilization of the waste heat of the hot and humid air.
[0018] The hot and humid air discharged from the solution regeneration spray chamber 8 serves as a low-temperature heat source for the heat pump evaporator 11, thereby improving the coefficient of performance of the heat pump and reducing operating power consumption.
[0019] The aforementioned drying room has its exhaust vent removed, and the heating chamber, which consists of the air heater 3 and the drying room dehumidification spray tower 4, has its fresh air vent removed.
[0020] The beneficial effects of this invention are: 1. Achieve independent temperature and humidity control, avoiding the need for supplemental electric heating during the "color setting period" and "drying period", thus reducing power consumption; 2. A closed-loop circulation system is adopted, eliminating the dehumidification outlet, preserving the natural aroma of the materials, and improving product quality; 3. Recover and regenerate waste heat from humid air to improve the coefficient of performance of the heat pump; 4. The system equipment is mature, the investment is moderate, and it is easy to promote and apply. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the heating system for the drying room with independent temperature and humidity control of the present invention when it is combined with a heat pump system.
[0022] Figure 2 This is a schematic diagram of the independent temperature and humidity control heating system for the drying room of the present invention, which is a separate heat pump system.
[0023] In the diagram: 1-Heat pump compressor, 2-Oven circulating fan, 3-Air heater, 4-Oven dehumidification spray tower, 5-Dilute solution pump, 6-Dilute solution heater I, 7-Concentrated solution cooler, 8-Solution regeneration spray chamber, 9-Concentrated solution pump, 10-Pressure fan, 11-Heat pump evaporator, 12-Thermal expansion valve I, 13-Drying filter I, 14-Solenoid valve I, 15-Storage tank I, 16-Thermal expansion valve II, 17-Dilute solution heater II, 18-Solution regeneration heat pump compressor with air inlet, 19-Solution regeneration heat pump evaporator, 20-Thermal expansion valve II, 21-Drying filter II, 22-Solenoid valve II, 23-Storage tank II. Detailed Implementation
[0024] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0025] Implementation Method 1: In a tobacco-growing area in Yunnan, it is proposed to build a tobacco curing barn.
[0026] like Figure 1As shown, the drying room heating system with independent temperature and humidity control, when the drying room heating system is a combined heat pump system, consists of three parts: heat pump heating cycle, solution absorption dehumidification cycle, and drying room air circulation. The drying room heating system includes a heat pump compressor 1, a drying room circulating fan 2, an air heater 3, a drying room dehumidification spray tower 4, a dilute solution pump 5, a dilute solution heater I6, a concentrated solution cooler 7, a solution regeneration spray chamber 8, a concentrated solution pump 9, a pressurizing fan 10, a heat pump evaporator 11, a thermal expansion valve I12, a drying filter I13, a solenoid valve 14, a liquid storage tank I15, and a thermal expansion valve II16. In the heat pump heating cycle, the high-temperature and high-pressure working fluid outlet of the heat pump compressor 1 is divided into two paths. One path is connected to the inlet of the dilute solution heater I6, and the other path is connected to the inlet of the air heater 3. The working fluid outlets of the dilute solution heater 6 and the air heater 3 are connected to the storage tank I15. The working fluid outlet of the storage tank I15 passes through the solenoid valve 14 and the dryer filter I13 in sequence and then splits into two paths. One path passes through the thermal expansion valve I12 and enters the heat pump evaporator 11 and then enters the main suction port of the heat pump compressor 1. The other path passes through the thermal expansion valve II16 and connects to the concentrated solution cooler 7 in sequence and then connects to the air replenishment port of the heat pump compressor 1. In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower 4 of the drying room is sent to the dilute solution heater I6 by the dilute solution pump 5 and then enters the solution regeneration spray chamber 8. The regenerated concentrated solution outlet in the solution regeneration spray chamber 8 is cooled by the concentrated solution pump 9 and the concentrated solution cooler 7 in sequence and then returned to the top of the dehumidification spray tower 4. In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower 4 through the return air inlet, then enters the air heater 3, and finally is sent back to the drying room through the drying room circulation fan 2. In the heat pump heating cycle and solution absorption dehumidification cycle, outdoor air flows sequentially through the solution regeneration spray chamber 8 and the pressurized fan 10 before entering the heat pump evaporator 11 and finally being discharged.
[0027] Among them, heat pump compressor 1 is a screw or scroll compressor with an intermediate gas inlet.
[0028] The low-pressure refrigerant vapor from the outlet of the concentrated solution cooler 7 is connected to the gas supply port of the heat pump compressor 1.
[0029] The system employs a prefabricated, lightweight steel insulated structure for intensive tobacco curing. Each curing barn has internal dimensions of 8000x2800x3700 mm for the loading chamber. Air heater 3 (heat pump condenser) uses a finned tube type, delivering hot air to the curing barn at 71°C. A perforated plate plenum is installed at the top of the loading chamber for downward air delivery. A centralized return air vent is located at the bottom of the insulation wall between the loading chamber and the heating chamber, fitted with a small-perforated wire mesh to prevent tobacco leaves from being drawn in. The curing barn's heat pump circulation uses a screw-type heat pump compressor 1 with an intermediate steam inlet. The heat pump working fluid is R502, and the design condensing temperature is 85°C and the evaporating temperature is 30°C. LiBr aqueous solution is used for dehumidification, with a concentrated solution concentration of 63.5 wt% and a dilute solution concentration of 58 wt%, with an appropriate amount of lithium chromate (Li2CrO4) corrosion inhibitor added. Other required equipment is as follows: Figure 1 The configuration shown is as follows: The heat pump working fluid piping, lithium bromide solution piping, heat pump evaporator 11, concentrated solution cooler 7, and dilute solution heater I6 heat transfer tubes are all made of copper; the solution regeneration spray chamber 8 and the drying oven dehumidification spray tower 4 are made of carbon steel; the drying oven dehumidification spray tower 4 uses polyvinyl chloride (PVC) S-wave packing. All piping and equipment are well insulated with foamed rubber and plastic insulation materials. Implementation Method Two:
[0030] like Figure 2 As shown, the drying oven heating system with independent temperature and humidity control is configured as follows: when the drying oven heating system is a separate heat pump system, the drying oven heating system consists of four parts: heat pump heating cycle, solution absorption dehumidification cycle, drying oven air circulation, and dilute solution heating heat pump heating cycle. The drying oven heating system includes a heat pump compressor 1, a drying oven circulating fan 2, an air heater 3, a drying oven dehumidification spray tower 4, a dilute solution pump 5, a concentrated solution cooler 7, a solution regeneration spray chamber 8, a concentrated solution pump 9, a pressurizing fan 10, a heat pump evaporator 11, a thermal expansion valve I12, a drying filter I13, a solenoid valve I14, a liquid storage tank I15, a thermal expansion valve II16, a dilute solution heater II17, a solution regeneration heat pump compressor 18 with a gas inlet 19, a solution regeneration heat pump evaporator 19, a thermal expansion valve II20, a drying filter 21, a solenoid valve II22, and a liquid storage tank II23. In the heat pump heating cycle, the high-temperature and high-pressure working fluid outlet of the heat pump compressor 1 is connected to the inlet of the air heater 3, and the working fluid outlet of the air heater 3 is connected to the liquid storage tank I15. The working fluid outlet of the liquid storage tank 15 passes through the solenoid valve 14 and the dryer filter I13 in sequence, and then enters the heat pump evaporator 11 through the thermal expansion valve I12 before entering the heat pump compressor 1. In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower 4 of the drying room is sent to the dilute solution heater II17 through the dilute solution pump 5 for heating and then enters the solution regeneration spray chamber 8. The regenerated concentrated solution outlet in the solution regeneration spray chamber 8 is cooled by the concentrated solution pump 9 and the concentrated solution cooler 7 in sequence and then returns to the top of the dehumidification spray tower 4. In the dilute solution heating heat pump heating cycle, the outlet of the solution regeneration heat pump compressor 18 with a gas inlet is connected to the dilute solution heater II17, and then sequentially connected to the liquid storage tank II23, the solenoid valve II22, and the dryer filter II21. The outlet of the dryer filter II21 is divided into two paths. One path is sequentially connected to the thermal expansion valve II16 and the concentrated solution cooler 7, and then returns to the gas inlet of the solution regeneration heat pump compressor 18 with a gas inlet. The other path passes through the thermal expansion valve II20 and connects to the solution regeneration heat pump evaporator 19, and finally enters the main suction port of the solution regeneration heat pump compressor 18 with a gas inlet. In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower 4 through the return air inlet, then enters the air heater 3, and finally is sent back to the drying room through the drying room circulation fan 2.
[0031] The specific embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.
Claims
1. A heating system for a drying room with independent temperature and humidity control, characterized in that: When the heating system of the drying room is a combined heat pump system; the heating system of the drying room consists of three parts: heat pump heating cycle, solution absorption dehumidification cycle and drying room air circulation. The heating system of the drying room includes heat pump compressor (1), drying room circulating fan (2), air heater (3), drying room dehumidification spray tower (4), dilute solution pump (5), dilute solution heater I (6), concentrated solution cooler (7), solution regeneration spray chamber (8), concentrated solution pump (9), pressurizing fan (10), heat pump evaporator (11), thermal expansion valve I (12), drying filter I (13), solenoid valve (14), liquid storage tank I (15) and thermal expansion valve II (16). In the heat pump heating cycle, the high temperature and high pressure working fluid outlet of the heat pump compressor (1) is divided into two paths. One path is connected to the inlet of the dilute solution heater I (6), and the other path is connected to the inlet of the air heater (3). The working fluid outlets of the dilute solution heater (6) and the air heater (3) are connected to the storage tank I (15). The working fluid outlet of the storage tank I (15) is divided into two paths after passing through the solenoid valve (14) and the dryer filter I (13). One path passes through the thermal expansion valve I (12) and enters the heat pump evaporator (11) and then enters the main suction port of the heat pump compressor (1). The other path passes through the thermal expansion valve II (16) and is connected to the concentrated solution cooler (7) and then to the air supply port of the heat pump compressor (1). In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower (4) of the drying room is fed into the dilute solution heater I (6) by the dilute solution pump (5) and then enters the solution regeneration spray chamber (8). The regenerated concentrated solution outlet in the solution regeneration spray chamber (8) is cooled by the concentrated solution pump (9) and the concentrated solution cooler (7) in sequence and then returns to the top of the dehumidification spray tower (4). In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower (4) through the return air inlet, then enters the air heater (3), and finally is sent back to the drying room through the drying room circulation fan (2); During the heat pump heating cycle and solution absorption dehumidification cycle, outdoor air flows through the solution regeneration spray chamber (8) and the pressurized fan (10) in sequence before entering the heat pump evaporator (11) and finally being discharged.
2. The independent temperature and humidity control heating system for a drying room according to claim 1, characterized in that: The heat pump compressor (1) is a screw or scroll compressor with an intermediate gas inlet.
3. The independent temperature and humidity control heating system for a drying room according to claim 1, characterized in that: The low-pressure refrigerant vapor at the outlet of the concentrated solution cooler (7) is fed into the gas inlet of the heat pump compressor (1).
4. The independent temperature and humidity control heating system for a drying room according to claim 1, characterized in that: The dilute solution is an aqueous solution of lithium bromide, lithium chloride, calcium chloride, magnesium chloride, triethylene glycol, potassium / sodium formate, potassium / sodium acetate, or an ionic liquid, or a mixed aqueous solution composed of two or more of the above hygroscopic agents in any ratio.
5. A heating system for a drying room with independent temperature and humidity control, characterized in that: When the heating system of the drying room is a separate heat pump system, the heating system of the drying room consists of four parts: heat pump heating cycle, solution absorption dehumidification cycle, drying room air circulation and dilute solution heating heat pump heating cycle. The heating system of the drying room includes heat pump compressor (1), drying room circulating fan (2), air heater (3), drying room dehumidification spray tower (4), dilute solution pump (5), concentrated solution cooler (7), solution regeneration spray chamber (8), concentrated solution pump (9), pressurizing fan (10), heat pump evaporator (11), thermal expansion valve I (12), drying filter I (13), solenoid valve I (14), liquid storage tank I (15), thermal expansion valve II (16), dilute solution heater II (17), solution regeneration heat pump compressor with air inlet (18), solution regeneration heat pump evaporator (19), thermal expansion valve II (20), drying filter (21), solenoid valve II (22) and liquid storage tank II (23). In the heat pump heating cycle, the high temperature and high pressure working fluid outlet of the heat pump compressor (1) is connected to the inlet of the air heater (3), the working fluid outlet of the air heater (3) is connected to the liquid storage tank I (15), and the working fluid outlet of the liquid storage tank (15) passes through the solenoid valve (14), the dryer filter I (13) in sequence, and then enters the heat pump evaporator (11) through the thermal expansion valve I (12) and then enters the heat pump compressor (1); In the solution absorption dehumidification cycle, the dilute solution outlet at the bottom of the dehumidification spray tower (4) of the drying room is fed into the dilute solution heater II (17) by the dilute solution pump (5) and then enters the solution regeneration spray chamber (8). The regenerated concentrated solution outlet in the solution regeneration spray chamber (8) is cooled by the concentrated solution pump (9) and the concentrated solution cooler (7) in sequence and then returns to the top of the dehumidification spray tower (4). In the heating cycle of the dilute solution heating heat pump, the outlet of the solution regeneration heat pump compressor (18) with a gas inlet is connected to the dilute solution heater II (17), and then sequentially connected to the liquid storage tank II (23), the solenoid valve II (22), and the dryer filter II (21). The outlet of the dryer filter II (21) is divided into two paths. One path is sequentially connected to the thermal expansion valve II (16) and the concentrated solution cooler (7) and then returns to the gas inlet of the solution regeneration heat pump compressor (18) with a gas inlet. The other path passes through the thermal expansion valve II (20) and connects to the solution regeneration heat pump evaporator (19), and finally enters the main suction port of the solution regeneration heat pump compressor (18) with a gas inlet. In the air circulation of the drying room, the humid air of the drying room enters the dehumidification spray tower (4) through the return air inlet, then enters the air heater (3), and finally is sent back to the drying room through the drying room circulation fan (2).