Drying system

Abstract

The invention relates to a drying system, which adopts a solar air heater, heat storage of a heat-conducting oil system, absorption refrigeration and heat pump heat supply dehumidification technology, realizes efficient utilization of solar heat in an article drying and cold using unit, solves the problem of utilization of the existing solar energy in the drying system, is convenient to install, maintain and maintain, is safe and efficient, and has the advantages of energy conservation and environmental protection. And social, economic and ecological benefits are expected to be remarkable.

Description

Technical Field

[0001] The invention relates to the technical field of drying, and in particular to a drying system using solar hot air device, heat pump and thermal oil heat storage technology. Background Art

[0002] Heat pump technology is widely used in the drying of medicinal materials, food, agricultural products, electronic products, etc. It has the characteristics of energy saving, environmental protection, fast drying, and low-temperature drying. However, heat pump drying equipment is currently mainly used for heating, and the heating temperature is not high. Changes in external relative humidity will affect the moisture content of the drying system's intake air, which in turn affects the drying effect and reduces the drying rate.

[0003] Solar thermal applications include solar water heating, solar heating, solar cooling, solar industrial and agricultural applications, and photovoltaic / thermal integration (PV / T) applications.

[0004] Solar water heating system: In 2009, there were more than 3,000 solar water heating system enterprises in China, with an annual output of about 40 million square meters and a total stock of 145 million square meters, accounting for 78% and 54% of the world respectively. Hot water is mainly produced by solar collectors, and the hot water produced is basically below 100°C. If the hot water temperature is 150-200°C, the water in this temperature range must maintain a pressure of 0.5-1.6MPa if it does not boil and vaporize, and it needs to be equipped with containers and pipeline valves with higher pressure. Steam may also flash out during use, which is not convenient for actual use. The hot water produced by the solar water heating system cannot be used in a timely and complete manner, which is easy to cause waste. In addition, the scaling and leakage problems of the solar water heating system are its inherent problems.

[0005] Photovoltaic system: The efficiency of photovoltaic power generation is relatively low, because photovoltaic panels mainly absorb visible light and infrared rays in solar radiation, and have a relatively weak absorption capacity for ultraviolet and blue light. In actual applications, the conversion efficiency of crystalline silicon photovoltaic cells is only 13% to 26%. Photovoltaic power generation technology requires silicon crystal materials, and the main raw material of crystalline silicon cells is pure silicon. Its production and purification process requires multiple chemical and physical processes, which not only consumes a lot of energy, but also causes certain pollution to the environment. Moreover, photovoltaic power is an unstable power source with limited access to the Internet, and must be equipped with energy storage devices.

[0006] my country is the largest producer and user of solar water heating systems and a major photovoltaic application country. How to transform from a major solar thermal utilization country to a strong solar thermal utilization country, store the heat obtained in the photothermal conversion process in a low-cost, simple and convenient way, eliminate the scaling problem of existing solar water heating systems, and combine absorption chillers with heat pump dehumidification technology for efficient operation of drying systems is worthy of in-depth research. Summary of the invention

[0007] The purpose of the present invention is to solve the problems existing in the existing drying technology, and to use solar energy hot air device and thermal oil heat storage technology to collect, store and supply heat from solar energy, give full play to the characteristics of thermal oil as "low pressure and high temperature" and high-quality heat storage and heat supply medium, realize the continuous application of solar energy heat in the drying process, use the thermal oil with heat storage to drive the absorption refrigeration mechanism for cooling and supplying cold, use heat pump technology to dehumidify and provide efficient heating at the same time, and finally realize the long-term and efficient heat utilization of solar energy in the drying system.

[0008] A drying system, comprising: Solar thermal air generator 7, recovers heat from solar energy, The dryer 6 dries the articles in the dryer 6 by using hot gas. The dehumidifier 11 removes part of the moisture in the gas coming out of the dryer 6 and increases the gas temperature. The dehumidifier and warmer 11 includes a gas compressor 111, a drying line condenser 112, a drying line evaporator 113 and connecting pipes thereof. The gas coming out of the dryer 6 returns to the solar hot air heater 7 through the circulation fan 4 and the return air pipeline 5, absorbs solar heat through the heat collecting pipe in the solar hot air heater 7, and is then transported to the dryer 6 to dry the items; or the gas coming out of the dryer 6 returns to the solar hot air heater 7 through the return air pipeline 5, absorbs solar heat through the heat collecting pipe in the solar hot air heater 7, and is then transported to the dryer 6 to dry the items through the ventilator 13, thereby forming a solar heat recovery and heat release circulation loop for the gas; Alternatively, the gas coming out of the dryer 6 is partially dehydrated by the drying line evaporator 113, and then absorbs heat by the drying line condenser 112, and then returns to the solar hot air heater 7 through the circulating fan 4 and the return air pipeline 5, and absorbs solar heat by the heat collecting pipe in the solar hot air heater 7, and then is transported to the dryer 6 to dry the items. Alternatively, the gas coming out of the dryer 6 is partially dehydrated by the drying line evaporator 113, and then absorbs heat by the drying line condenser 112, and then returns to the solar hot air heater 7 through the return air pipeline 5, and absorbs solar heat by the heat collecting pipe in the solar hot air heater 7, and then is transported to the dryer 6 to dry the items through the ventilator 13, thereby forming a solar heat recovery and heat release circulation loop for the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor 111 releases heat to the gas coming out of the dryer 6 and having some moisture removed by the drying line evaporator 113 through the drying line condenser 112, and enters the drying line evaporator 113 through the drying line condenser 112 to release cold energy, so that part of the moisture in the gas coming out of the dryer 6 is condensed into liquid water and discharged, and the gaseous working fluid coming out of the drying line evaporator 113 returns to the gas compressor 111 for pressurization, thereby forming a heating and dehumidification circulation loop of the gaseous heat pump working fluid.

[0009] At night or on cloudy days: The gas coming out of the dryer 6 has some moisture removed from it by the drying line evaporator 113, and then absorbs heat through the drying line condenser 112, and then returns to the dryer 6 to dry the items through the circulating fan 4 and the return air pipeline 5. Alternatively, the gas coming out of the dryer 6 has some moisture removed from it by the drying line evaporator 113, and then absorbs heat through the drying line condenser 112, and then is transported to the dryer 6 to dry the items through the ventilator 13, thereby forming a heat absorption and heat release circulation loop of the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor 111 releases heat to the gas coming out of the dryer 6 and having some moisture removed by the drying line evaporator 113 through the drying line condenser 112, and enters the drying line evaporator 113 through the drying line condenser 112 to release cold energy, so that part of the moisture in the gas coming out of the dryer 6 is condensed into liquid water and discharged, and the gaseous working fluid coming out of the drying line evaporator 113 returns to the gas compressor 111 for pressurization, thereby forming a heating and dehumidification circulation loop of the gaseous heat pump working fluid.

[0010] A heat storage heat exchanger 14 is provided: The heat transfer oil from the heat transfer oil tank 1 is pressurized by the heat transfer oil pump 17 and sent to the heat storage heat exchanger 14 to exchange heat with the hot air sent by the solar hot air device 7. The temperature of the heat transfer oil is increased and returned to the heat transfer oil tank 1 through the heat storage heat transfer oil return pipeline 34, thereby forming a heat storage circulation loop of the heat transfer oil in the heat transfer oil tank 1. The gas coming out of the heat storage heat exchanger 14 returns to the solar heat heater 7 through the circulation fan 4 and the return air pipeline 5, absorbs solar heat through the heat collecting pipes in the solar heat heater 7, and is then transported to the heat storage heat exchanger 14; or the gas coming out of the heat storage heat exchanger 14 returns to the solar heat heater 7 through the return air pipeline 5, absorbs solar heat through the heat collecting pipes in the solar heat heater 7, and is then transported to the heat storage heat exchanger 14 through the ventilator 13, thereby forming another solar heat recovery and heat release circulation loop of the gas.

[0011] At night or on cloudy days: the solar energy recovered by the solar hot air device 7 is not enough to supply the dryer 6, the heat transfer oil in the heat transfer oil tank 1 is pressurized by the heat transfer oil pump 17 and sent to the heat storage heat exchanger 14 to exchange heat with the gas sent by the solar hot air device 7, and the heat transfer oil with reduced temperature returns to the heat transfer oil tank 1. The gas sent into the solar hot air heater 7 is heated by the heat storage heat exchanger 14 and then sent to the dryer 6 to dry the items. The gas coming out of the dryer 6 returns to the solar hot air heater 7 through the circulating fan 4 and the return air pipeline 5, passes through the heat collecting pipe in the solar hot air heater 7, and is then sent to the heat storage heat exchanger 14. Alternatively, the gas sent into the solar hot air heater 7 is heated by the heat storage heat exchanger 14 and then sent to the dryer 6 to dry the items. The gas coming out of the dryer 6 returns to the solar hot air heater 7 through the return air pipeline 5, passes through the heat collecting pipe in the solar hot air heater 7, and is then sent to the heat storage heat exchanger 14 through the ventilator 13, thereby forming a heat release circulation loop of the heat storage heat transfer oil in the heat transfer oil tank 1 and a heat absorption and heat supply circulation loop of the gas.

[0012] With absorption chiller: The absorption refrigerator is used to absorb the heat of the heat transfer oil and realize the refrigeration cycle process of the refrigerant, including: Generator 23, condenser 24, evaporator 25, absorber 21 and solution pump 22, The heat transfer oil in the heat transfer oil tank 1 enters the heat transfer oil pump 17 for pressure increase, and the pressure-increased heat transfer oil is delivered to the generator 23 of the absorption refrigerator to heat the concentrated solution of the refrigerant in the generator 23, and then returns to the heat transfer oil tank 1 through the return heat transfer oil pipeline 33, thereby forming a heat supply circulation loop for the heat transfer oil stored in the heat transfer oil tank 1. The high-temperature gaseous refrigerant 31 generated by the heat transfer oil heating the concentrated solution of the refrigerant in the generator 23 enters the evaporator 25 through the condenser 24 and the throttle valve F10, absorbs the heat of the cooling medium sent by the cold unit 27, and the low-temperature gaseous refrigerant 32 generated by evaporation in the evaporator 25 returns to the absorber 21, contacts with the dilute solution of the refrigerant formed in the generator 23 sent from the dilute solution regulating valve F9, and forms a concentrated solution of the refrigerant. The concentrated solution of the refrigerant in the absorber 21 is then returned to the generator 23 through the solution pump 22, thereby forming a refrigerant circulation loop of the absorption refrigerator. The cooling medium coming out of the cooling unit 27 is pressurized by the cooling medium booster 28 and then sent to the evaporator 25 to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator 25. The cooling medium with the absorbed cold and lowered temperature returns to the cooling unit 27 for cooling. Alternatively, the cooling medium coming out of the cooling unit 27 enters the evaporator 25 to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator 25. The cooling medium with the absorbed cold and lowered temperature returns to the cooling unit 27 for cooling, thereby forming a cooling medium circulation loop in which the cooling medium is charged with cold and then supplies cold to the cooling unit 27.

[0013] The cooling unit 27 has various usage types and refers to a cooling location in the drying system, such as a refrigeration and air conditioning unit required for an office, a refrigeration and pre-cooling unit in a drying system, and the like.

[0014] The cooling medium of the condenser 24 and the absorber 21 is air, water, sodium chloride in water liquid or ethylene glycol in water liquid, for example, Figure 1 As shown, the cooling medium sent by the cooling medium booster 39 through the condenser 24 cools the high-temperature gaseous refrigerant 31, absorbs the heat of the high-temperature gaseous refrigerant 31, and the formed high-temperature cooling medium is discharged. The high-temperature gaseous refrigerant 31 condenses to form a liquid refrigerant and is sent to the evaporator 25. In the absorber 21, the refrigerant from the dilute solution regulating valve F9 absorbs the low-temperature gaseous refrigerant 32 into the dilute solution to form a refrigerant-concentrated solution, and the released heat is removed by the cooling medium sent by the cooling medium booster 39, and the formed high-temperature cooling medium is discharged; When the cooling medium is air, the cooling medium booster 39 is a fan, and an open cycle is adopted. The air is sent to the condenser 24 and the absorber 21 through the cooling medium booster 39, and the heat released when the high-temperature gaseous refrigerant 31 of the condenser 24 is condensed is absorbed, and the heat released when the refrigerant of the absorber 21 absorbs the dilute solution to form the low-temperature gaseous refrigerant 32 to form the refrigerant to form the concentrated solution is formed, and the high-temperature absorber outlet cooling medium 41 and the condenser outlet cooling medium 42 are discharged; When the cooling medium is liquid, the cooling medium booster 39 is a liquid circulation pump. The cooling medium is sent to the condenser 24 and the absorber 21 through the cooling medium booster 39 to absorb the heat released when the high-temperature gaseous refrigerant 31 of the condenser 24 is condensed, and the heat released when the refrigerant of the absorber 21 absorbs the dilute solution to form the low-temperature gaseous refrigerant 32 to form the refrigerant to the concentrated solution. The high-temperature absorber outlet cooling medium 41 and condenser outlet cooling medium 42 are formed, enter the cooling tower 43 for cooling, and then return to the cooling medium booster 39, thereby forming a cooling medium circulation loop.

[0015] The absorption refrigerator selects a corresponding absorption refrigerator refrigerant pair, including but not limited to ammonia-water, ammonia-sodium thiocyanate solution, the refrigerant pair provided by CN202210567342.6 (dimethyl ether-ionic liquid refrigerant), the refrigerant pair provided by CN202211615323.2 (R134a-DMETG solution), or the refrigerant pair provided by CN202310535508.0 (ammonia-ionic liquid refrigerant).

[0016] A heat exchanger 18 is provided: The heat transfer oil in the heat transfer oil tank 1 enters the heat transfer oil pump 17 to increase the pressure, and the pressurized heat transfer oil is transported to the heat exchanger 18 to heat the heated working medium 19 into the heat supply medium 20, and the heat transfer oil coming out of the heat exchanger 18 returns to the heat transfer oil tank 1, thereby forming a heat supply circulation loop of the heat transfer oil in the heat transfer oil tank 1. For example, the heat exchanger 18 is used as an organic working medium evaporator of the organic Rankine cycle unit. At this time, the heat transfer oil passing through the heat exchanger 18 is the heat source of the organic working medium evaporator, which is used to heat and vaporize the liquid organic working medium transported by the organic working medium circulation pump to generate high-temperature gaseous organic working medium, enter the organic working medium gas turbine to drive the organic working medium generator to generate electricity, and the low-temperature and low-pressure organic working medium vapor coming out of the organic working medium gas turbine enters the organic working medium condenser to be liquefied, and then returns to the organic working medium circulation pump, thereby forming an organic working medium Rankine cycle loop.

[0017] The heat collecting tube of the solar thermal air heater 7 includes but is not limited to a through heat collecting tube 10, a heat pipe or a single-pass heat collecting tube.

[0018] When the solar thermal air heater 7 uses a through heat collecting pipe 10, the through heat collecting pipe 10 can be connected in series, in parallel or in series and in parallel: For example, Figure 1 As shown, a plurality of through heat collecting tubes 10 are used in parallel, and two groups of solar hot air heaters 7 (double header hot air heaters) are used in series. The solar hot air heater 7 comprises a left header 8, a right header 9, and a through heat collecting tube 10. A plurality of through heat collecting tubes 10 connected in parallel are arranged between the left header 8 and the right header 9. The through heat collecting tubes 10 absorb the heat of solar energy and heat the gas entering the right header 9. The generated high-temperature gas is drawn out from the left header 8, transported to the drying chamber 11 for drying the Panax notoginseng, and then returned to the right header 9, thereby forming a closed-loop gas circulation loop of the through heat collecting tube type solar hot air heater 7; the outlet hot air of one group of solar hot air heaters 7 is used in series as the inlet gas of another group of solar hot air heaters; For example, Figure 1As shown, multiple through-collecting tubes 10 are used in series and two groups of solar thermal air heaters 7 (trough-type thermal air heaters) are used in series. The solar thermal air heater 7 includes a trough-type collector 37, a concentrating plate 38 and a through-collecting tube 10. Gas enters the multiple through-collecting tubes 10 connected in series. The through-collecting tubes 10 absorb the heat of the solar energy and heat the incoming gas. The generated high-temperature gas is drawn out and used in series as the incoming gas of another group of solar thermal air heaters.

[0019] Preferably, the through-tube heat collecting tube 10 adopts a vacuum collector, the inner layer of the heat collecting tube is a stainless steel tube, the outer layer is a glass tube plus metal bellows at both ends, and the outer surface of the inner tube is coated with a selective absorption coating to achieve maximum absorption rate of direct solar radiation and minimum infrared wave re-radiation.

[0020] A supplementary heat device 46 is provided: the supplementary heat device 46 is arranged between the solar hot air device 7 and the heat storage heat exchanger 14, and adopts electric heating, compressed air heat, fuel combustion heat, etc. to supplement the heat required by the drying chamber 6 and the heat transfer oil tank 1. For example, the supplementary heat medium 47 adopts the hot air 47 formed by the combustion of natural gas, which enters the supplementary heat device 46 to heat the air sent by the solar hot air device 7, and the low-temperature flue gas formed is discharged by discharging the supplementary heat medium 48.

[0021] The circulating fan 4 is provided with an adjusting damper 3 for adjusting the air supply volume of the circulating fan 4 .

[0022] The ventilator 13 is provided with a hot air regulating damper 12 for adjusting the air supply volume of the ventilator 13 .

[0023] The circulating fan 4 and the ventilator 13 are substantially the same, and the names are only used to distinguish them.

[0024] The circulating fan 4 or the ventilator 13 is a centrifugal, axial flow, screw or vortex fan.

[0025] The solar heat generator 7 is provided with necessary support rods or support frames to securely, stably and effectively fix the solar heat generator to avoid tipping accidents caused by strong winds.

[0026] The inlet pipeline of the thermal oil pump 17 is provided with a filter for filtering solid impurity particles in the thermal oil in the inlet pipeline.

[0027] The heat transfer oil tank 1 in the heat transfer oil system plays the role of oil and gas separation, buffering, heat storage and storage, and insulation measures need to be taken.

[0028] The heat transfer oil system is provided with necessary exhaust valves and safety valves.

[0029] The thermal oil tank 1 adopts a horizontal or vertical structure, preferably a vertical structure, which facilitates the compact arrangement of the system.

[0030] The valve names in this application are only used for distinction, and some of the actual functions are the same.

[0031] The circulating fan 4 or the ventilator 13 adopts a variable frequency speed regulation operation mode, and flexibly adjusts the air supply volume and air supply pressure when the sunshine and heating conditions change.

[0032] The absorption refrigerator of this system can adopt measures such as heat recovery, cooling recovery, mass recovery and distillation.

[0033] The present invention can be provided with corresponding dust removal equipment as required to remove dust from the circulating gas, such as a bag-type cyclone dust removal or an electrostatic dust removal equipment with a bypass.

[0034] Pipes, instruments, valves, regulating bypasses, etc. not described in this application are matched with reference to mature technologies in known organic heat carrier boilers, solar water heating projects, and drying systems.

[0035] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing known technologies.

[0036] Compared with the prior art, the present invention has the following advantages: 1. Compared with the existing technology, the present invention eliminates the problem of low heat utilization efficiency of the existing solar water heating system and photovoltaic utilization system, and uses the solar hot air device to safely and efficiently recover solar heat and store heat in the heat transfer oil. The heat transfer oil at nearly normal pressure and high temperature can facilitate users to make timely, flexible and efficient heat utilization during the drying of items, realize continuous drying and long-term solar heat utilization, and has unparalleled advantages over the hot water recovery system; during continuous rainy periods, the heat can be supplemented conveniently through the supplementary heat device to ensure the smooth drying of items; 2. Compared with the existing technology, the present invention uses solar hot air generators to safely and efficiently recover solar heat and store heat in heat transfer oil, and then uses the stored heat transfer oil to drive the absorption refrigerator for cooling and cold supply, which is used for low-temperature storage of goods, heat dissipation of office data centers, air conditioning of office rooms, etc., which is convenient for users to make timely, flexible and efficient cold utilization and realize long-term continuous cooling; 3. Compared with the existing solar water heater technology that directly heats water with heat collecting tubes, since the heat collecting tubes pass through gas, dust is not easy to accumulate, and the heat collecting tubes have high heat transfer efficiency. Unlike the heat collecting tubes that directly heat water, scale is not generated, which affects the heat exchange effect and then blocks the heat collecting tubes. The maintenance cost is extremely low and the operation cycle is greatly extended. In winter, unlike the heat collecting tubes that directly heat water, there will be no ice blockage of the water supply pipeline due to low temperature, and cracking and leakage at the connection between the heat collecting tank and the heat collecting tube; 4. Compared with the existing technology, the heat exchanger heated by thermal oil can be conveniently used for external heating or organic Rankine cycle power generation of solar energy, thereby improving the power supply capacity of the drying system to cope with emergencies; 5. Compared with the prior art, the dehumidifier and warmer in the present invention not only efficiently utilizes the heat pump technology for heating, but also utilizes the drying line evaporator in the heat pump working medium cycle to partially dehumidify the moisture in the dryer outlet gas, and then increases the temperature through the drying line condenser, effectively reducing the humidity of the gas entering the dryer and enhancing its drying capacity. While dehumidifying, the heat at the dryer outlet is directly recovered for heat pump heating, which greatly improves the energy utilization rate; 6. Compared with the prior art, the technical scheme of the present invention is flexible, diverse and efficient in operation. For example, when the sun is abundant, the solar hot air heater is directly used for heating and drying, and the heat storage and heat transfer oil is used to provide continuous drying energy. When the humidity of the dryer outlet gas is high and affects the drying efficiency, the dehumidifier is started to adjust the humidity of the dryer circulating gas to a suitable range. For another example, high-quality organic vegetables are freeze-dried by first freezing them at low temperature in the cold unit of the absorption refrigerator, so that the free water in the high-quality vegetables freezes, expands, and solidifies to form a skeleton, and then the dryer is used for low-temperature drying to remove moisture (for example, 40 to 60°C). The dehydrated vegetables are of high quality, have a long shelf life, and the nutrients therein are easy to be absorbed and utilized. 7. Compared with the prior art, the technical solution of the present invention has strong versatility and is suitable for drying operations of various items; 8. Compared with the prior art, the technical solution of the present invention has strong versatility and is suitable for drying operations of various items. For example, the use of inert gas such as nitrogen for drying operations can effectively avoid oxidation and deterioration of the dried items. It can be dried at low temperature or high temperature, and has a large drying temperature range, which can give full play to the characteristics of the heat transfer oil of the present invention, such as low pressure, high temperature and strong heat storage capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a schematic diagram of the structure of a drying system of the present invention.

[0038] Figure 1Middle: 1-heat transfer oil tank, 2-gas space of heat transfer oil tank, 3-adjusting damper, 4-circulating fan, 5-return air duct, 6-dryer, 7-solar heat heater, 8-left header, 9-right header, 10-through collector, 11-dehumidifier, 111-gas compressor, 112-drying line condenser, 113-drying line evaporator, 114-water receiver, 12-hot air measuring damper, 13-ventilator, 14-heat storage heat exchanger, 15-hot air pipe Line, 16-pressure gauge, 17-thermal oil pump, 18-heat exchanger, 19-heated medium, 20-heating medium, 21-absorber, 22-solution pump, 23-generator, 24-condenser, 25-evaporator, 26-cooling medium pipeline, 27-cold unit, 28-cooling medium booster (when the cooling medium is liquid, it is the cooling medium circulation pump; when the cooling medium is gas, it is the cooling medium circulation fan), 29-concentrated solution pipeline, 30-dilute solution pipe duct, 31-high temperature gaseous refrigerant, 32-low temperature gaseous refrigerant, 33-return heat transfer oil pipeline, 34-heat storage heat transfer oil return pipeline, 35-heat storage hot air return pipeline, 36-dryer outlet gas pipeline, 37-trough collector, 38-condensing plate, 39-cooling medium booster (cooling medium circulation pump when the cooling medium is liquid; blower when the cooling medium is air), 40-cooling medium, 41-absorber outlet cooling medium, 42-condenser Cooling medium at the outlet of the device, 43-cooling tower, 44-enhanced heat and moisture exchange element, 45-cooling tower fan, 46-supplementary heat device, 47-supplementary heat medium, 48-discharge of supplementary heat medium; F1 to F5, F7 to F20 are valves, among which: F2-discharge valve, F3-safety valve, F4-pressure gauge valve, F9-dilute solution regulating valve, F10-throttle valve, F18-exhaust valve, F19-drying line throttle valve, F20-drain valve, and the remaining valves are regulating valves or stop valves. DETAILED DESCRIPTION

[0039] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0040] Embodiment 1: As attached Figure 1 As shown, a drying system comprises: Solar thermal air generator 7, recovers heat from solar energy, The dryer 6 dries the articles in the dryer 6 by using hot gas. The dehumidifier 11 removes part of the moisture in the gas coming out of the dryer 6 and then returns it to the dryer 6. The dehumidifier and warmer 11 includes a gas compressor 111, a drying line condenser 112, a drying line evaporator 113 and connecting pipes thereof. The gas coming out of the dryer 6 is partially dehydrated by the drying line evaporator 113, and then absorbs heat by the drying line condenser 112, and then returns to the solar hot air heater 7 through the circulating fan 4 and the return air pipeline 5, and absorbs solar heat by the heat collecting pipe in the solar hot air heater 7, and then is transported to the dryer 6 to dry the items, and the liquid water condensed from the drying line evaporator 113 is discharged into the water receiver 114 through the drain valve F20. Alternatively, the gas coming out of the dryer 6 is partially dehydrated by the drying line evaporator 113, and then absorbs heat by the drying line condenser 112, and then returns to the solar hot air heater 7 through the return air pipeline 5, and absorbs solar heat by the heat collecting pipe in the solar hot air heater 7, and then is transported to the dryer 6 to dry the items through the ventilator 13, and the liquid water condensed from the drying line evaporator 113 is discharged into the water receiver 114 through the drain valve F20, thereby forming a solar heat recovery and heat release circulation loop for the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor 111 releases heat to the gas coming out of the dryer 6 and having part of its moisture removed by the drying line evaporator 113 through the drying line condenser 112, and enters the drying line evaporator 113 through the drying line condenser 112 and the drying line throttle valve F19 to release cold air, so that part of the moisture in the gas coming out of the dryer 6 is condensed into liquid water and discharged, and the gaseous heat pump working fluid coming out of the drying line evaporator 113 returns to the gas compressor 111 to be pressurized and heated, thereby forming a heating and dehumidification circulation loop for the gaseous working fluid.

[0041] At night or on cloudy days: The gas coming out of the dryer 6 has some moisture removed from it by the drying line evaporator 113, and then absorbs heat through the drying line condenser 112, and then returns to the solar hot air heater 7 through the circulating fan 4 and the return air pipeline 5, and then is transported to the dryer 6 to dry the items. Alternatively, the gas coming out of the dryer 6 has some moisture removed from it by the drying line evaporator 113, and then absorbs heat through the drying line condenser 112, and then returns to the solar hot air heater 7 through the return air pipeline 5, and then is transported to the dryer 6 to dry the items through the ventilator 13, thereby forming a solar heat recovery and heat release circulation loop for the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor 111 releases heat to the gas coming out of the dryer 6 and having some moisture removed by the drying line evaporator 113 through the drying line condenser 112, and enters the drying line evaporator 113 through the drying line condenser 112 to release cold energy, so that part of the moisture in the gas coming out of the dryer 6 is condensed into liquid water and discharged, and the gaseous heat pump working fluid coming out of the drying line evaporator 113 returns to the gas compressor 111 for pressurization, thereby forming a heating and dehumidification circulation loop of the gaseous working fluid.

[0042] A heat storage heat exchanger 14 is provided: The heat transfer oil from the heat transfer oil tank 1 is pressurized by the heat transfer oil pump 17 and sent to the heat storage heat exchanger 14 to exchange heat with the hot air sent by the solar hot air device 7. The temperature of the heat transfer oil is increased and returned to the heat transfer oil tank 1 through the heat storage heat transfer oil return pipeline 34, thereby forming a heat storage circulation loop of the heat transfer oil in the heat transfer oil tank 1. The gas coming out of the heat storage heat exchanger 14 returns to the solar heat heater 7 through the circulation fan 4 and the return air pipeline 5, absorbs solar heat through the heat collecting pipes in the solar heat heater 7, and is then transported to the heat storage heat exchanger 14; or the gas coming out of the heat storage heat exchanger 14 returns to the solar heat heater 7 through the return air pipeline 5, absorbs solar heat through the heat collecting pipes in the solar heat heater 7, and is then transported to the heat storage heat exchanger 14 through the ventilator 13, thereby forming another solar heat recovery and heat release circulation loop of the gas.

[0043] At night or on cloudy days: the solar energy recovered by the solar hot air device 7 is not enough to supply the dryer 6, the heat transfer oil in the heat transfer oil tank 1 is pressurized by the heat transfer oil pump 17 and sent to the heat storage heat exchanger 14 to exchange heat with the gas sent by the solar hot air device 7, and the heat transfer oil with reduced temperature returns to the heat transfer oil tank 1. The gas sent into the solar hot air heater 7 is heated by the heat storage heat exchanger 14 and then sent to the dryer 6 through the valve F17 to dry the articles. The gas coming out of the dryer 6 returns to the solar hot air heater 7 through the drying line evaporator 113, the drying line condenser 112, the circulating fan 4, and the return air pipeline 5, passes through the heat collecting pipe in the solar hot air heater 7, and is then transported to the heat storage heat exchanger 14. Alternatively, the gas sent into the solar hot air heater 7 is heated by the heat storage heat exchanger 14 and then sent to the dryer 6 to dry the articles. The gas coming out of the dryer 6 returns to the solar hot air heater 7 through the drying line evaporator 113, the drying line condenser 112, and the return air pipeline 5, passes through the heat collecting pipe in the solar hot air heater 7, and is then transported to the heat storage heat exchanger 14 through the fan 13, thereby forming a heat release circulation loop of the heat storage heat transfer oil in the heat transfer oil tank 1 and a heat absorption and heat supply circulation loop of the gas.

[0044] With absorption chiller: The absorption refrigerator is used to absorb the heat of the heat transfer oil and realize the refrigeration cycle process of the refrigerant, including: Generator 23, condenser 24, evaporator 25, absorber 21 and solution pump 22, The heat transfer oil in the heat transfer oil tank 1 enters the heat transfer oil pump 17 for pressure increase, and the pressure-increased heat transfer oil is delivered to the generator 23 of the absorption refrigerator to heat the concentrated solution of the refrigerant in the generator 23, and then returns to the heat transfer oil tank 1 through the return heat transfer oil pipeline 33, thereby forming a heat supply circulation loop for the heat transfer oil stored in the heat transfer oil tank 1. The high-temperature gaseous refrigerant 31 generated by the heat transfer oil heating the concentrated solution of the refrigerant in the generator 23 enters the evaporator 25 through the condenser 24 and the throttle valve F10, absorbs the heat of the cooling medium sent by the cold unit 27, and the low-temperature gaseous refrigerant 32 generated by evaporation in the evaporator 25 returns to the absorber 21, contacts with the dilute solution of the refrigerant formed in the generator 23 sent from the dilute solution regulating valve F9, and forms a concentrated solution of the refrigerant. The concentrated solution of the refrigerant in the absorber 21 is then returned to the generator 23 through the solution pump 22, thereby forming a refrigerant circulation loop of the absorption refrigerator. The cooling medium coming out of the cooling unit 27 is pressurized by the cooling medium booster 28 and then sent to the evaporator 25 to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator 25. The cooling medium with the absorbed cold and lowered temperature returns to the cooling unit 27 for cooling. Alternatively, the cooling medium coming out of the cooling unit 27 enters the evaporator 25 to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator 25. The cooling medium with the absorbed cold and lowered temperature returns to the cooling unit 27 for cooling, thereby forming a cooling medium circulation loop in which the cooling medium is charged with cold and then supplies cold to the cooling unit 27.

[0045] The cooling unit 27 has various usage types and refers to a cooling location in the drying system, such as a refrigeration and air conditioning unit required for an office, a refrigeration and pre-cooling unit in a drying system, and the like.

[0046] The cooling medium of the condenser 24 and the absorber 21 is air, water, sodium chloride in water liquid or ethylene glycol in water liquid, for example, Figure 1 As shown, the cooling medium sent by the cooling medium booster 39 through the condenser 24 cools the high-temperature gaseous refrigerant 31, absorbs the heat of the high-temperature gaseous refrigerant 31, and the formed high-temperature cooling medium is discharged. The high-temperature gaseous refrigerant 31 condenses to form a liquid refrigerant and is sent to the evaporator 25. In the absorber 21, the refrigerant from the dilute solution regulating valve F9 absorbs the low-temperature gaseous refrigerant 32 into the dilute solution to form a refrigerant-concentrated solution, and the released heat is removed by the cooling medium sent by the cooling medium booster 39, and the formed high-temperature cooling medium is discharged; When the cooling medium is air, the cooling medium booster 39 is a fan, and an open cycle is adopted. The air is sent to the condenser 24 and the absorber 21 through the cooling medium booster 39, and the heat released when the high-temperature gaseous refrigerant 31 of the condenser 24 is condensed is absorbed, and the heat released when the refrigerant of the absorber 21 absorbs the dilute solution to form the low-temperature gaseous refrigerant 32 to form the refrigerant to form the concentrated solution is formed, and the high-temperature absorber outlet cooling medium 41 and the condenser outlet cooling medium 42 are discharged; When the cooling medium is liquid, the cooling medium booster 39 is a liquid circulation pump. The cooling medium is sent to the condenser 24 and the absorber 21 through the cooling medium booster 39 to absorb the heat released when the high-temperature gaseous refrigerant 31 of the condenser 24 is condensed, and the heat released when the refrigerant of the absorber 21 absorbs the dilute solution to form the low-temperature gaseous refrigerant 32 to form the refrigerant to the concentrated solution. The high-temperature absorber outlet cooling medium 41 and condenser outlet cooling medium 42 are formed, enter the cooling tower 43 for cooling, and then return to the cooling medium booster 39, thereby forming a cooling medium circulation loop.

[0047] The absorption refrigerator selects ammonia-water as the refrigerant pair.

[0048] A heat exchanger 18 is provided: The heat transfer oil in the heat transfer oil tank 1 enters the heat transfer oil pump 17 to increase the pressure, and the pressurized heat transfer oil is transported to the heat exchanger 18 to heat the heated working medium 19 into the heat supply medium 20, and the heat transfer oil coming out of the heat exchanger 18 returns to the heat transfer oil tank 1, thereby forming a heat supply circulation loop of the heat transfer oil in the heat transfer oil tank 1. For example, the heat exchanger 18 is used as an organic working medium evaporator of the organic Rankine cycle unit. At this time, the heat transfer oil passing through the heat exchanger 18 is the heat source of the organic working medium evaporator, which is used to heat and vaporize the liquid organic working medium transported by the organic working medium circulation pump to generate high-temperature gaseous organic working medium, enter the organic working medium gas turbine to drive the organic working medium generator to generate electricity, and the low-temperature and low-pressure organic working medium vapor coming out of the organic working medium gas turbine enters the organic working medium condenser to be liquefied, and then returns to the organic working medium circulation pump, thereby forming an organic working medium Rankine cycle loop.

[0049] The heat collecting pipe of the solar thermal air heater 7 adopts a through heat collecting pipe 10 .

[0050] For example, Figure 1 As shown, a plurality of through heat collecting tubes 10 are used in parallel, and two groups of solar hot air heaters 7 (double header hot air heaters) are used in series. The solar hot air heater 7 comprises a left header 8, a right header 9, and a through heat collecting tube 10. A plurality of through heat collecting tubes 10 connected in parallel are arranged between the left header 8 and the right header 9. The through heat collecting tubes 10 absorb the heat of solar energy and heat the gas entering the right header 9. The generated high-temperature gas is drawn out from the left header 8, transported to the drying chamber 11 for drying the Panax notoginseng, and then returned to the right header 9, thereby forming a closed-loop gas circulation loop of the through heat collecting tube type solar hot air heater 7; the outlet hot air of one group of solar hot air heaters 7 is used in series as the inlet gas of another group of solar hot air heaters; For example, Figure 1As shown, multiple through-collecting tubes 10 are used in series and two groups of solar thermal air heaters 7 (trough-type thermal air heaters) are used in series. The solar thermal air heater 7 includes a trough-type collector 37, a concentrating plate 38 and a through-collecting tube 10. Gas enters the multiple through-collecting tubes 10 connected in series. The through-collecting tubes 10 absorb the heat of the solar energy and heat the incoming gas. The generated high-temperature gas is drawn out and used in series as the incoming gas of another group of solar thermal air heaters.

[0051] Preferably, the through-tube heat collecting tube 10 adopts a vacuum collector, the inner layer of the heat collecting tube is a stainless steel tube, the outer layer is a glass tube plus metal bellows at both ends, and the outer surface of the inner tube is coated with a selective absorption coating to achieve maximum absorption rate of direct solar radiation and minimum infrared wave re-radiation.

[0052] A supplementary heat device 46 is provided: the supplementary heat device 46 is arranged between the solar hot air device 7 and the heat storage heat exchanger 14, and adopts electric heating, compressed air heat, fuel combustion heat, etc. to supplement the heat required by the drying chamber 6 and the heat transfer oil tank 1. For example, the supplementary heat medium 47 adopts the hot air 47 formed by the combustion of natural gas, which enters the supplementary heat device 46 to heat the air sent by the solar hot air device 7, and the low-temperature flue gas formed is discharged by discharging the supplementary heat medium 48.

[0053] The circulating fan 4 is provided with an adjusting damper 3 for adjusting the air supply volume of the circulating fan 4 .

[0054] The ventilator 13 is provided with a hot air regulating damper 12 for adjusting the air supply volume of the ventilator 13 .

[0055] The circulating fan 4 and the ventilator 13 are substantially the same, and the names are only used to distinguish them.

[0056] The circulating fan 4 or the ventilator 13 is a centrifugal, axial flow, screw or vortex fan.

[0057] The solar heat generator 7 is provided with necessary support rods or support frames to securely, stably and effectively fix the solar heat generator to avoid tipping accidents caused by strong winds.

[0058] The inlet pipeline of the thermal oil pump 17 is provided with a filter for filtering solid impurity particles in the thermal oil in the inlet pipeline.

[0059] The heat transfer oil tank 1 in the heat transfer oil system plays the role of oil and gas separation, buffering, heat storage and storage, and insulation measures need to be taken.

[0060] The heat transfer oil system is provided with necessary exhaust valves and safety valves.

[0061] The thermal oil tank 1 adopts a horizontal or vertical structure, preferably a vertical structure, which facilitates the compact arrangement of the system.

[0062] The valve names in this application are only used for distinction, and some of the actual functions are the same.

[0063] The circulating fan 4 or the ventilator 13 adopts a variable frequency speed regulation operation mode, and flexibly adjusts the air supply volume and air supply pressure when the sunshine and heating conditions change.

[0064] The absorption refrigerator of this system can adopt measures such as heat recovery, cooling recovery, mass recovery and distillation.

[0065] The present invention can be provided with corresponding dust removal equipment as required to remove dust from the circulating gas, such as a bag-type cyclone dust removal or an electrostatic dust removal equipment with a bypass.

[0066] Pipes, instruments, valves, regulating bypasses, etc. not described in this application are matched with reference to mature technologies in known organic heat carrier boilers, solar water heating projects, and drying systems.

[0067] Parts not mentioned in this application, such as safety accessories, interlocking protection devices and automatic control, are equipped with existing known technologies.

[0068] Although the present invention has been disclosed as above with preferred embodiments, they are not intended to limit the present invention. Anyone familiar with the art can make various changes or modifications without departing from the spirit and scope of the present invention, which also belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the definition of the claims of this application.

Claims

1. A drying system, characterized in that: include: The solar thermal air generator (7) recovers heat from solar energy. The dryer (6) dries the articles in the dryer (6) by using hot gas. The dehumidifier (11) removes part of the moisture in the gas coming out of the dryer (6) and increases the temperature of the gas. The dehumidifier and warmer (11) comprises a gas compressor (111), a drying line condenser (112), a drying line evaporator (113) and connecting pipes thereof. The gas from the dryer (6) returns to the solar hot air heater (7) via the circulating fan (4) and the return air pipeline (5), absorbs solar heat through the heat collecting pipe in the solar hot air heater (7), and is then transported to the dryer (6) to dry the items; or the gas from the dryer (6) returns to the solar hot air heater (7) via the return air pipeline (5), absorbs solar heat through the heat collecting pipe in the solar hot air heater (7), and is then transported to the dryer (6) to dry the items via the ventilator (13), thereby forming a solar heat recovery and heat release circulation loop for the gas; Alternatively, the gas coming out of the dryer (6) is partially dehydrated by the drying line evaporator (113), then absorbs heat by the drying line condenser (112), then returns to the solar hot air heater (7) via the circulating fan (4) and the return air duct (5), absorbs solar heat by the heat collecting tube in the solar hot air heater (7), and then is transported to the dryer (6) to dry the items; or the gas coming out of the dryer (6) is partially dehydrated by the drying line evaporator (113), then absorbs heat by the drying line condenser (112), then returns to the solar hot air heater (7) via the return air duct (5), absorbs solar heat by the heat collecting tube in the solar hot air heater (7), and then is transported to the dryer (6) to dry the items, thereby forming a solar heat recovery and heat release circulation loop for the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor (111) releases heat to the gas coming out of the dryer (6) and having some moisture removed by the drying line evaporator (113) through the drying line condenser (112), and then enters the drying line evaporator (113) through the drying line condenser (112) to release cold energy, so that part of the moisture in the gas coming out of the dryer (6) is condensed into liquid water and discharged. The gaseous heat pump working fluid coming out of the drying line evaporator (113) returns to the gas compressor (111) to be pressurized, thereby forming a heating and dehumidification circulation loop for the gaseous working fluid.

2. The drying system according to claim 1, characterized in that: At night or on cloudy days: The gas coming out of the dryer (6) passes through the drying line evaporator (113) to remove part of its moisture, then passes through the drying line condenser (112) to absorb heat, and then returns to the dryer (6) through the circulation fan (4) and the return air pipeline (5) to dry the items; or the gas coming out of the dryer (6) passes through the drying line evaporator (113) to remove part of its moisture, then passes through the drying line condenser (112) to absorb heat, and then is transported to the dryer (6) through the ventilator (13) to dry the items, thereby forming a heat absorption and heat release circulation loop of the gas. The gaseous heat pump working fluid with increased pressure coming out of the gas compressor (111) releases heat to the gas coming out of the dryer (6) and having some moisture removed by the drying line evaporator (113) through the drying line condenser (112), and then enters the drying line evaporator (113) through the drying line condenser (112) to release cold energy, so that part of the moisture in the gas coming out of the dryer (6) is condensed into liquid water and discharged. The gaseous heat pump working fluid coming out of the drying line evaporator (113) returns to the gas compressor (111) to be pressurized, thereby forming a heating and dehumidification circulation loop for the gaseous working fluid.

3. The drying system according to claim 1, characterized in that: A heat storage heat exchanger (14) is provided: The heat transfer oil from the heat transfer oil tank (1) is pressurized by the heat transfer oil pump (17) and sent to the heat storage heat exchanger (14) to exchange heat with the hot air sent by the solar hot air device (7). The temperature of the heat transfer oil is increased and the heat transfer oil is returned to the heat transfer oil tank (1) through the heat storage heat transfer oil return pipeline (34), thereby forming a heat storage circulation loop of the heat transfer oil in the heat transfer oil tank (1). The gas coming out of the heat storage heat exchanger (14) returns to the solar heat generator (7) via the circulation fan (4) and the return air pipeline (5), absorbs solar heat through the heat collecting pipe in the solar heat generator (7), and is then transported to the heat storage heat exchanger (14); or the gas coming out of the heat storage heat exchanger (14) returns to the solar heat generator (7) via the return air pipeline (5), absorbs solar heat through the heat collecting pipe in the solar heat generator (7), and is then transported to the heat storage heat exchanger (14) via the ventilator (13), thereby forming another solar heat recovery and heat release circulation loop of the gas.

4. The drying system according to claim 3, characterized in that: At night or on cloudy days: if the solar energy recovered by the solar hot air device (7) is insufficient to supply the dryer (6), the heat transfer oil in the heat transfer oil tank (1) is pressurized by the heat transfer oil pump (17) and sent to the heat storage heat exchanger (14) to exchange heat with the gas sent from the solar hot air device (7). The heat transfer oil with a lowered temperature returns to the heat transfer oil tank (1). The gas sent into the solar hot air device (7) is heated by the heat storage heat exchanger (14) and then sent into the dryer (6) to dry the articles. The gas coming out of the dryer (6) returns to the solar hot air device (7) through the circulation fan (4) and the return air pipeline (5), passes through the heat collecting pipe in the solar hot air device (7), and is then sent to the heat storage heat exchanger (14). Alternatively, the gas sent into the solar hot air device (7) is heated by the heat storage heat exchanger (14) and then sent into the dryer (6) to dry the articles. The gas coming out of the dryer (6) returns to the solar hot air device (7) through the return air pipeline (5), passes through the heat collecting pipe in the solar hot air device (7), and is then sent to the heat storage heat exchanger (14) through the ventilator (13), thereby forming a heat release circulation loop of the heat storage oil in the heat transfer oil tank (1) and a heat absorption and heat supply circulation loop of the gas.

5. The drying system according to claim 3, characterized in that: An absorption refrigerator is provided: the absorption refrigerator is used to absorb the heat of the heat transfer oil and realize the refrigeration cycle process of the refrigerant, including: Generator (23), condenser (24), evaporator (25), absorber (21) and solution pump (22), The heat transfer oil in the heat transfer oil tank (1) enters the heat transfer oil pump (17) for pressure increase, and the pressurized heat transfer oil is delivered to the generator (23) to heat the concentrated solution of the refrigerant in the generator (23), and then returns to the heat transfer oil tank (1) through the return heat transfer oil pipeline (33), thereby forming a heat supply circulation loop for the heat transfer oil in the heat transfer oil tank (1). The high-temperature gaseous refrigerant (31) generated by the heat transfer oil heating the concentrated solution of the refrigerant pair in the generator (23) enters the evaporator (25) through the condenser (24) and the throttle valve F10, absorbs the heat of the cooling medium sent by the cold unit (27), and the low-temperature gaseous refrigerant (32) generated by evaporation in the evaporator (25) returns to the absorber (21), contacts with the dilute solution of the refrigerant pair formed in the generator (23) sent from the dilute solution regulating valve F9, and forms a concentrated solution of the refrigerant pair. The concentrated solution of the refrigerant pair in the absorber (21) then returns to the generator (23) through the solution pump (22), thereby forming a refrigerant circulation loop of the absorption refrigerator. The cooling medium from the cold unit (27) is pressurized by the cooling medium booster (28) and then sent to the evaporator (25) to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator (25). The cooling medium that has absorbed the cold and whose temperature has been lowered returns to the cold unit (27) for cooling. Alternatively, the cooling medium from the cold unit (27) enters the evaporator (25) to absorb the cold released by the evaporation of the liquid refrigerant in the evaporator (25). The cooling medium that has absorbed the cold and whose temperature has been lowered returns to the cold unit (27) for cooling. Thus, a cooling medium circulation loop is formed in which the cooling medium is charged with cold and then supplies cold to the cold unit (27).

6. The drying system according to claim 3, characterized in that: A heat exchanger (18) is provided: The heat transfer oil in the heat transfer oil tank (1) enters the heat transfer oil pump (17) for pressure increase. The pressure-increased heat transfer oil is transported to the heat exchanger (18) to heat the heated working medium (19) into a heat supply medium (20). The heat transfer oil from the heat exchanger (18) returns to the heat transfer oil tank (1), thereby forming a heat supply circulation loop for the heat transfer oil storing heat in the heat transfer oil tank (1).

7. The drying system according to claim 3, characterized in that: A supplementary heat device (46) is provided: the supplementary heat device (46) is arranged between the solar hot air device (7) and the heat storage heat exchanger (14), and uses electric heating, compressed air heat, and fuel combustion heat to heat the gas to supplement the heat required by the drying chamber (6) and / or the heat transfer oil tank (1).

8. The drying system according to claim 1, characterized in that: The heat collecting tube of the solar thermal air heater (7) comprises a through heat collecting tube (10), a heat pipe or a single-pass heat collecting tube.

9. The drying system according to claim 5, characterized in that: The refrigerant pair selected by the absorption refrigerator includes ammonia-water, ammonia-sodium thiocyanate solution, dimethyl ether-ionic liquid refrigerant, R134a-DMETG solution or ammonia-ionic liquid refrigerant.

10. The drying system according to claim 8, characterized in that: The heat collecting tube adopts a vacuum collector, the inner layer of the heat collecting tube is a stainless steel tube, the outer layer is a glass tube, and the outer surface of the inner tube is coated with a selective absorption coating.

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