An air path opening and closing combined drying device

Abstract

The present invention relates to a drying device combining air passage opening and closing, which includes a heating and dehumidifying chamber. At least one inner cavity and at least one outer cavity are separated by a partition in the heating and dehumidifying chamber. The outer cavity communicates with the ambient air, and the inner cavity communicates with the curing barn to form a circulation channel for the drying air flow. A fresh air inlet and a moisture exhaust port are also provided on the side wall of the inner cavity or the partition. When the drying air flow is in a closed-loop circulation, the fresh air inlet and the moisture exhaust port are both closed, and the drying air flow circulates in the closed-loop circulation channel composed of the inner cavity and the curing barn. When the drying air flow is in a partially open-loop circulation, the fresh air inlet and the moisture exhaust port are both opened. The warm and humid return air in the curing barn enters the inner cavity, and a part of the warm and humid return air entering the inner cavity is discharged out of the inner cavity through the moisture exhaust port. At the same time, ambient fresh air is supplemented into the inner cavity through the fresh air inlet. The present invention solves the problem that during the yellowing period, since the cells of fresh tobacco leaves and the like are still in the stage of aerobic respiration and living metabolism, the self-heat generation of tobacco leaves and the like is relatively large, resulting in excessive heat in the curing barn and the dry bulb temperature exceeding the target value.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pump drying, and particularly relates to a drying device combining air passage opening and closing. Background Art

[0002] Since green development has become the mainstream concept of society, in the drying fields of agricultural products, wood, paper, seafood, etc., heat pumps have gradually replaced coal-fired hot blast stoves, gas-fired hot blast stoves, and oil-fired hot blast stoves and become the dominant technology.

[0003] Heat pump baking of tobacco leaves is the focus in the field of heat pump drying of agricultural products. After years of research and development by many heat pump enterprises, the heat pump technology for tobacco leaf baking has gradually matured. The heat pump tobacco baking room combined with the bulk curing barn and the heat preservation panel house stipulated in the document No. 418 of the General Office of the State Tobacco Monopoly Administration in 2009 is gradually being popularized in the tobacco-growing areas.

[0004] During the 170-hour baking process of tobacco leaves, the dry and wet bulb temperatures in the baking room change slowly and the control accuracy of the dry and wet bulb temperatures is required not to exceed the target value by ±1°C. In order to adapt to this strict baking process, the heat pump tobacco baking room can only adopt the "one-to-one" cooperation mode of one heat pump unit corresponding to one baking room. This heat pump unit continuously adjusts its own heating capacity and dehumidifying capacity during operation to meet the strict baking process requirements of tobacco leaves.

[0005] Under the "one-to-one" cooperation mode of one heat pump unit corresponding to one baking room and the batch baking condition of fresh tobacco leaves, the industry generally recovers the waste heat of the warm and humid air discharged during the dehumidification of the tobacco baking room by a heat pump, forming a heat pump unit structure composed of two heat pump subsystems, namely an internal dehumidification and internal heating heat pump subsystem and an external heat absorption and internal heating heat pump subsystem.

[0006] However, the drying of high-value-added agricultural products such as tobacco leaves and Chinese herbal medicines is usually accompanied by complex baking process requirements. Please refer to Figure 1 , for example, the baking time of tobacco leaves is up to more than 170 hours in a week, and the baking process is very strict. The 170-hour baking process of tobacco leaves usually needs to be decomposed into three major baking process periods, namely yellowing, color fixing, and stem drying, and ten detailed process stages. The dry and wet bulb temperatures in the baking room change slowly. The dry bulb temperature starts from 30°C and slowly rises all the way to 68°C, and the wet bulb temperature starts from 30°C and slowly rises all the way to 40°C. And the control accuracy of the dry and wet bulb temperatures is required not to exceed the target value by ±1°C to achieve the technical goal of baking the tobacco leaves yellow, fragrant, and dry.

[0007] Among them, during the first baking process period, that is, during the yellowing period of tobacco leaves, since the temperature difference between the inside and outside of the baking room is small and the heat leakage is small, and the more than 30,000 fresh tobacco leaves hanging in the standard baking room are still in the stage of aerobic respiration and living metabolism, the self-heat generation of the tobacco leaves is relatively large, resulting in a situation where there is often too much heat in the baking room and the dry bulb temperature exceeds the target value, and heat needs to be discharged to the outside of the baking room environment.

[0008] To solve the problem of exhausting the excess heat inside the curing barn during the yellowing stage, a drying heat pump unit with a closed-circuit circulation of the drying air flow in the curing barn is adopted. Usually, a heat pump system with the function of three-in-one is set up, that is, a set of heat pump system is equipped with three heat exchangers. One heat exchanger is arranged in the ambient air, and two heat exchangers are arranged in the closed-circuit air flow channel of the curing barn. Through the switching of the solenoid valves, three functions of internal dehumidification and internal heating, internal dehumidification and external heat discharge, and external heat absorption and internal heating are respectively realized.

[0009] Although this kind of heat pump system with the function of "three-in-one" adds the function of internal dehumidification and external heat discharge in addition to the main functions of external heat absorption and internal heating and internal dehumidification and internal heating, and solves the problem of exhausting the excess heat inside the curing barn during the yellowing stage, the structure of the heat pump system is too complex. On the pipeline between the compressor, throttle valve and three heat exchangers, a four-way valve, two solenoid valves and three one-way valves are set, resulting in a significant decline in the stability and reliability of the heat pump system. Summary of the Invention

[0010] To solve the above problems, the present invention provides an air path opening and closing combined drying device, including a heating and dehumidifying chamber. At least one inner cavity and at least one outer cavity are separated in the heating and dehumidifying chamber by a partition. The outer cavity communicates with the ambient air, and the inner cavity communicates with the curing barn to form a circulation channel for the drying air flow.

[0011] A fresh air inlet and a moisture exhaust port are also provided on the side wall or partition of the inner cavity.

[0012] When the drying air flow is in a closed-circuit circulation, the fresh air inlet and the moisture exhaust port are both closed, and the drying air flow circulates in the closed-circuit circulation channel composed of the inner cavity and the curing barn.

[0013] When the drying air flow is in a partial open-circuit circulation, the fresh air inlet and the moisture exhaust port are both opened. The warm and humid return air in the curing barn enters the inner cavity. Part of the warm and humid return air entering the inner cavity is discharged out of the inner cavity through the moisture exhaust port. At the same time, the ambient fresh air is supplemented into the inner cavity through the fresh air inlet.

[0014] Preferably, a fresh air damper is provided on the fresh air inlet, and a moisture exhaust damper is provided on the moisture exhaust port. The fresh air damper and the moisture exhaust damper are simultaneously opened and simultaneously closed by the same driving device.

[0015] Preferably, in the inner cavity, a moisture exhaust guide plate is arranged above the moisture exhaust port. The moisture exhaust guide plate is rotatably arranged on the partition or the side wall of the inner cavity. When the moisture exhaust damper is opened, the moisture exhaust guide plate is unfolded; when the moisture exhaust damper is closed, the moisture exhaust guide plate is retracted.

[0016] Preferably, the moisture exhaust guide plate and the moisture exhaust damper are driven by the same driving device.

[0017] Preferably, the driving device is an electric push rod, which is installed on the side wall or partition of the inner cavity. The output end of the electric push rod is fixedly connected to the fresh air damper and the moisture exhaust damper respectively through a connecting member;

[0018] The moisture exhaust guiding plate is hinged to the connecting member through a connecting rod; or, the moisture exhaust guiding plate is connected to the moisture exhaust damper through a connecting rope or, and is connected to the side wall or partition of the inner cavity through an elastic member.

[0019] Preferably, the output end of the electric push rod is vertically arranged;

[0020] The connecting member includes a connecting cross bar. The middle of the connecting cross bar is fixedly connected to the output end of the electric push rod. Both ends of the connecting cross bar are respectively connected to a connecting vertical bar, and both ends of the connecting vertical bar are fixedly connected to the fresh air damper and the moisture exhaust damper respectively;

[0021] When the moisture exhaust guiding plate is hinged to the connecting member through a connecting rod, both ends of the connecting rod are respectively hinged to the connecting cross bar and the moisture exhaust guiding plate.

[0022] Preferably, an air inlet and an air outlet for communicating with the baking room are provided on the inner cavity wall;

[0023] The device further includes at least one internal dehumidification and internal heating heat pump unit and at least one external heat absorption and internal heating heat pump unit:

[0024] The first condenser of the external heat absorption and internal heating heat pump unit is arranged in the inner cavity corresponding to the air outlet, and the first evaporator of the internal dehumidification and internal heating heat pump unit is arranged in the outer cavity;

[0025] The second condenser of the internal dehumidification and internal heating heat pump unit is arranged in the inner cavity corresponding to the air outlet, and the internal dehumidification modules of the internal dehumidification and internal heating heat pump unit are all arranged in the inner cavity and located between the air inlet and the air outlet;

[0026] When the drying air flow is in a closed loop, the fresh air inlet and the moisture exhaust outlet are closed at the same time. The warm and humid return air in the baking room enters the inner cavity through the air inlet. A part of the warm and humid return air entering the inner cavity first passes through the internal dehumidification module and then mixes with another part of the warm and humid return air, and then is heated by the first condenser and the second condenser and discharged to the baking room through the air outlet;

[0027] When the drying air flow is in a partially open circuit circulation, the fresh air inlet and the moisture exhaust outlet are opened simultaneously. Fresh air from the environment enters the inner cavity through the fresh air inlet, is heated by the first condenser and the second condenser, and then is discharged from the air outlet into the baking room. At the same time, the warm and humid return air in the baking room enters the inner cavity through the air inlet. A part of the warm and humid return air entering the inner cavity is discharged outside the inner cavity through the moisture exhaust outlet, and the other part of the warm and humid return air is heated by the first condenser and the second condenser and then is discharged from the air outlet into the baking room.

[0028] Preferably, the fresh air inlet is located above the moisture exhaust outlet, the fresh air inlet is located below the first condenser and the second condenser, and the moisture exhaust outlet is located below the internal dehumidification module.

[0029] Preferably, the internal dehumidification module includes a second evaporator.

[0030] Preferably, the internal dehumidification module further includes a cross-flow heat exchanger. The cross-flow heat exchanger includes a hot fluid channel and a cold fluid channel. The air inlet of the second evaporator communicates with the hot fluid channel of the cross-flow heat exchanger, and the air outlet of the second evaporator communicates with the air inlet of the second condenser through the cold fluid channel of the cross-flow heat exchanger.

[0031] Compared with the prior art, the present invention has the following technical effects:

[0032] 1. The present invention provides an air path opening and closing combined drying device with an internal dehumidification and external heat exhaust function. By providing a fresh air inlet and a moisture exhaust outlet on the side wall or partition of the inner cavity, it solves the problem that during the yellowing period, because the fresh tobacco leaves and other cells are still in the stage of aerobic respiration and living metabolism, the self-heat generation of tobacco leaves and the like is relatively large, resulting in excessive heat in the baking room and the dry bulb temperature exceeding the target value.

[0033] 2. The present invention provides an air path opening and closing combined drying device that uses a heat pump unit. Since a fresh air damper and a moisture exhaust damper are provided on the side wall or partition of the inner cavity, the problem of exhausting excess heat in the baking room during the yellowing period is solved. The heat pump subsystem no longer undertakes the function of internal dehumidification and external heat exhaust, and the system returns to simplicity. Both the internal dehumidification and internal heating heat pump subsystem and the external heat absorption and internal heating heat pump subsystem in the heat pump unit return to a simple single-loop refrigeration system composed of a compressor, a condenser, a throttle valve, and an evaporator. The four-way valve, solenoid valve, check valve, and branch pipelines in the "one machine with three functions" system are removed, simplifying the fluorine circuit structure of the heat pump subsystem and greatly improving the reliability of the system.

[0034] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings. In the drawings:

[0036] Figure 1 is the dry and wet bulb curve graph of the three-stage tobacco leaf baking process;

[0037] Figure 2 is the structural schematic diagram of the combined device of an air path opening and closing combined drying device and a baking room provided by the preferred embodiment of the present invention;

[0038] Figure 3 is the schematic diagram of the principle of an air path opening and closing combined drying device provided by the preferred embodiment of the present invention;

[0039] Figure 4 is the internal circulation heating schematic diagram of an air path opening and closing combined drying device provided by the preferred embodiment of the present invention (the fresh air damper and the exhaust damper are both closed);

[0040] Figure 5 is the internal circulation heating schematic diagram of an air path opening and closing combined drying device provided by the preferred embodiment of the present invention (the fresh air damper and the exhaust damper are both open);

[0041] Figure 6 and Figure 7 is the front view of the fresh air damper and the exhaust damper with synchronous opening and closing provided by the preferred embodiment of the present invention;

[0042] Figure 8 is the rear view of the fresh air damper and the exhaust damper with synchronous opening and closing provided by the preferred embodiment of the present invention;

[0043] Figure 9 is the side view of the fresh air damper and the exhaust damper with synchronous opening and closing provided by the preferred embodiment of the present invention;

[0044] Figure 10 is the structural schematic diagram of the fresh air damper and the exhaust damper with moisture exhaust guide plates provided by the preferred embodiment of the present invention;

[0045] Figure 11 is the longitudinal sectional view of the fresh air damper and the exhaust damper with moisture exhaust guide plates provided by an embodiment of the present invention;

[0046] Figure 12 and Figure 13 is the state diagram of the fresh air damper and the exhaust damper with moisture exhaust guide plates closed provided by an embodiment of the present invention;

[0047] Figure 14Schematic diagram of external moisture exhaust during partial open-circuit circulation of the drying air flow provided by an embodiment of the present invention;

[0048] Figure 15 Schematic diagram of closed-circuit circulation of the drying air flow provided by an embodiment of the present invention;

[0049] Figure 16 Schematic structural diagram of the moisture exhaust guide plate being opened synchronously with the fresh air damper and the exhaust damper provided by another embodiment of the present invention;

[0050] Figure 17 Schematic structural diagram of the moisture exhaust guide plate being closed synchronously with the fresh air damper and the exhaust damper provided by another embodiment of the present invention;

[0051] Figure 18 Schematic diagram of external moisture exhaust during partial open-circuit circulation of the drying air flow provided by another embodiment of the present invention;

[0052] Figure 19 Schematic diagram of closed-circuit circulation of the drying air flow provided by another embodiment of the present invention;

[0053] Figure 20 Schematic structural diagram of the fresh air damper and the exhaust damper being arranged on the inner cavity side wall provided by the preferred embodiment of the present invention. Detailed implementation manners

[0054] The following will combine Figures 2 to 20 to describe in detail an air path opening and closing combined drying device provided by the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation manners and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments. Those skilled in the art can modify and polish it without changing the spirit and content of the present invention.

[0055] Please refer to Figures 2 to 20 , the present invention provides an air path opening and closing combined drying device. There is no specific limitation on the baking heat source for this device, which can be a heat pump, or a coal-fired hot blast stove, a gas-fired hot blast stove, an oil-fired hot blast stove, etc. The drying device generally includes a heating and dehumidifying chamber 1, and the heating and dehumidifying chamber 1 has the functions of internal dehumidification and internal heating and external heat absorption and internal heating. In order to solve the problem of external discharge of excess heat inside the curing barn during the yellowing period of tobacco leaves, Chinese herbal medicines, etc., therefore, it is necessary to discharge part of the warm and humid air entering the internal dehumidification and internal heating module to the outside. Therefore, the present invention divides the internal space of the heating and dehumidifying chamber 1 into at least one inner cavity 11 and at least one outer cavity 12 through a partition 13. The outer cavity 12 communicates with the ambient air, and the inner cavity 11 communicates with the curing barn 2 to form a circulation channel for the drying air flow;

[0056] A fresh air inlet 112 and a moisture exhaust port 113 are further provided on the inner cavity side wall 1103 or the partition 13;

[0057] When the drying air flow is in a closed-loop circulation, the fresh air inlet 112 and the moisture exhaust outlet 113 are both closed, and the drying air flow circulates in the closed-loop circulation channel formed by the inner cavity 11 and the baking chamber 2.

[0058] When the drying air flow is in a partial open-loop circulation, the fresh air inlet 112 and the moisture exhaust outlet 113 are both opened. The warm and humid return air in the baking chamber 2 enters the inner cavity 11, and part of the warm and humid return air entering the inner cavity 11 is discharged outside the inner cavity 11 through the moisture exhaust outlet 113. At the same time, ambient fresh air is supplemented into the inner cavity 11 through the fresh air inlet 112.

[0059] The opening and closing of the fresh air inlet 112 and the moisture exhaust outlet 113 can be controlled manually or by a driving device. The present invention does not make specific limitations in this regard. In this embodiment, the latter is preferred. For example, it can be driven by the same driving device or by two driving devices respectively. The following takes the simultaneous opening and closing of the fresh air inlet 112 and the moisture exhaust outlet 113 controlled by the same driving device as an example for detailed description.

[0060] Embodiment 1

[0061] Please refer to Figures 2 to 9 , the drying device provided in this embodiment takes a heat pump unit as an example. This heat pump unit is composed of at least one internal dehumidification and internal heating heat pump unit 15 and at least one external heat absorption and internal heating heat pump unit 14. The internal dehumidification and internal heating heat pump unit 15 is used for internal dehumidification and internal heating, and the external heat absorption and internal heating heat pump unit 14 is used for external heat absorption and internal heating.

[0062] In this embodiment, an air inlet 1102 and an air outlet 1101 for communicating with the baking chamber 2 are provided on the wall of the inner cavity 11. The air inlet 1102 is located below the inner cavity 11, and the air outlet 1101 is located above the inner cavity 11. A first fan 16 is provided at the air outlet 1101.

[0063] The external heat absorption and internal heating heat pump unit 14 includes a first compressor 141, a first condenser 143, a first throttling device 142, and a first evaporator 144. The first compressor 141, the first condenser 143, the first throttling device 142, and the first evaporator 144 are sequentially connected to form a first circulation system for refrigerant circulation. Among them, the first condenser 143 is disposed in the inner cavity 11 corresponding to the air outlet 1101, and the first evaporator 144 is disposed in the outer cavity 12.

[0064] Please refer to Figure 20, on the wall of the outer cavity 12, there are an outer cavity air outlet and an outer cavity air inlet 121. The first evaporator 144 is arranged at the outer cavity air outlet. And at this outer cavity air outlet, a second blower 17 is further arranged outside the first evaporator 144. This second blower 17 is used to suck the external environmental air into the outer cavity 12 through the outer cavity air inlet 121, and after passing through the first evaporator 144 (the external environmental air releases heat to the refrigerant in the first evaporator 144), it is then discharged into the external environment.

[0065] In this embodiment, there is no limitation on the setting of the outer cavity air inlet 121. Preferably, a plurality of small holes are opened on the outer cavity wall.

[0066] The internal dehumidification and internal heating heat pump unit 15 includes a second compressor 151, a second condenser 153, a second throttling device 152 and an internal dehumidification module. The internal dehumidification module can be an evaporator or a combination of an evaporator and a cross-flow heat exchanger. In order to further improve the working efficiency of the drying device, in this embodiment, a combination of an evaporator and a cross-flow heat exchanger is taken as an example, that is, the internal dehumidification module includes a second evaporator 155 and a cross-flow heat exchanger 154. The second compressor 151, the second condenser 153, the second throttling device 152 and the second evaporator 155 are sequentially connected to form a second circulation system for refrigerant circulation. In this embodiment, the cross-flow heat exchanger 154 is a plate heat exchanger, which includes a hot fluid channel and a cold fluid channel. The inlet of the hot fluid channel of the cross-flow heat exchanger 154 is communicated with the air inlet 1102 of the inner cavity 11. The outlet of the hot fluid channel of the cross-flow heat exchanger 154 is communicated with the air path inlet of the second evaporator 155. The air path outlet of the second evaporator 155 is communicated with the air path inlet of the second condenser 153 through the cold fluid channel of the cross-flow heat exchanger 154. At the air path outlet of the cold fluid channel of the cross-flow heat exchanger 154, a third blower 18 is further arranged, which is used to close the fresh air inlet 112 and the moisture exhaust port 113 simultaneously when the drying air flow is in a closed-loop circulation. A part of the warm and humid return air entering the inner cavity 11 is discharged after passing through the internal dehumidification module (this part of the warm and humid return air is pre-cooled in the hot fluid channel of the cross-flow heat exchanger 154, enters the second evaporator 155 for further cooling and dehumidification, and then enters the cold fluid channel of the cross-flow heat exchanger 154 for reheating and then discharged).

[0067] In this embodiment, the second condenser 153 is disposed in the inner cavity 11 corresponding to the air outlet 1101. The internal dehumidification module is disposed in the inner cavity 11 and is located between the air inlet 1102 and the air outlet 1101. The fresh air inlet 112 is located above the moisture exhaust port 113, and the fresh air inlet 112 is located below the first condenser 143 and the second condenser 153. The moisture exhaust port 113 is located below the internal dehumidification module. The first condenser 143 and the second condenser 153 are arranged in sequence below the air outlet 1101. Here, there is no limitation on whether the first condenser 143 is above or below the second condenser 153.

[0068] In this embodiment, there is no specific limitation on the installation positions of the first compressor 141, the first throttling device 142, the second compressor 151, and the second throttling device 152. Preferably, the first compressor 141, the first throttling device 142, the second compressor 151, and the second throttling device 152 are arranged in the outer cavity 12.

[0069] A fresh air damper 19 is provided on the fresh air inlet 112, and a moisture exhaust damper 110 is provided on the moisture exhaust port 113. The fresh air damper 19 and the moisture exhaust damper 110 are driven by the same driving device, so that the fresh air inlet 112 and the moisture exhaust port 113 are opened and closed simultaneously.

[0070] An air path opening and closing combined drying device provided by the present invention has the functions of internal dehumidification and internal heating, and external heat absorption and internal heating. It can continuously filter the water vapor in the air in the baking room 2 to reduce the relative humidity and absolute humidity of the closed-loop circulating drying air flow, and can continuously input heat into the baking room 2 to increase the dry bulb temperature of the drying air flow in the baking room 2; and because the refrigerant evaporation pressure of the internal dehumidification module for heat recovery is significantly higher than that of the external heat absorption evaporator (the first evaporator 144), the heating energy efficiency ratio of the whole system is at a high level.

[0071] An air path opening and closing combined drying device provided by this embodiment has the function of internal dehumidification and external heat exhaust to reduce the dry and wet bulb temperatures in the baking room 2.

[0072] Taking the baking of tobacco leaves as an example, in the yellowing period of tobacco leaves, when there is excess heat in the baking room 2 and the dry bulb temperature is higher than the target value, the fresh air damper 19 and the moisture exhaust damper 110 on the middle partition 13 can be synchronously driven by the electric push rod 112 (the driving device is taken as the electric push rod 112) on the partition 13. While supplementing fresh air, the warm and humid air is discharged, and the excess heat in the baking room 2 is discharged, so that the dry and wet bulb temperatures in the baking room 2 return to the target value.

[0073] An air circuit opening and closing combined drying device of the present invention. When the drying air flow is in a closed-loop circulation, the fresh air damper 19 and the moisture exhaust damper 110 are synchronously closed, and the drying air flow circulates in a closed-loop channel formed by the upper and lower connection of the inner cavity 11 and the curing barn 2. That is, the warm and humid return air from the curing barn 2 enters the inner cavity 11 through the air inlet 1102. A part of the warm and humid return air entering the inner cavity 11 first enters the high-efficiency internal dehumidification module with pre-cooling of the incoming air and reheating of the outgoing air, is pre-cooled in the hot fluid channel of the cross-flow heat exchanger 154, then enters the second evaporator 155 for further cooling and dehumidification, and then enters the cold fluid channel of the cross-flow heat exchanger 154 for reheating and then is discharged, completing the filtration of moisture; this part of the air flow after leaving the internal dehumidification module then converges with another part of the warm and humid return air entering the inner cavity 11, flows through the first condenser 143 and the second condenser 153 together, and is sent back to the curing barn 2 after being reheated again; the heat source of the condenser of the heat pump unit can be the heat absorbed by the second evaporator 155 from the warm and humid return air in the curing barn 2, can be the heat absorbed by the first evaporator 144 from the external ambient air, or can be the sum of the above two, depending on the heat demand of the curing barn 2;

[0074] When the drying air flow is in a partial open-loop circulation, the fresh air damper 19 and the moisture exhaust damper 110 are synchronously opened. Ambient fresh air enters the inner cavity 11 through the fresh air inlet 112, is heated by the first condenser 143 and the second condenser 153 and then discharged to the curing barn 2 through the air outlet 1101; at the same time, the warm and humid return air in the curing barn 2 enters the inner cavity 11 through the air inlet 1102. A part of the warm and humid return air entering the inner cavity 11 is discharged to the outside of the inner cavity 11 through the moisture exhaust port 113, and another part of the warm and humid return air is heated by the first condenser 143 and the second condenser 153 and then discharged to the curing barn 2 through the air outlet 1101. When the drying air flow is in a partial open-loop circulation, the fresh air damper 19 and the moisture exhaust damper 110 are synchronously opened to promote the replenishment of fresh air and the discharge of warm and humid air flow, so that the excess heat generated by the self-heating of the tobacco leaves when the fresh tobacco leaf cells are still in the stage of aerobic respiration and living metabolism is discharged to the environment, and the dry and wet bulb temperatures of the curing barn 2 return to the target values. When the drying air flow is in a partial open-loop circulation, it can continuously filter the water vapor in the air in the curing barn 2 to reduce the relative humidity and absolute humidity of the drying air flow, and can continuously input heat to the drying air flow to increase the dry bulb temperature of the curing barn 2; and because the refrigerant evaporation pressure of the internal dehumidification module for heat recovery is significantly higher than that of the external heat absorption evaporator, the heating energy efficiency ratio of the whole system is at a high level.

[0075] An air circuit opening and closing combined drying device provided in this embodiment has the function of internal dehumidification and external heat discharge to solve the problem that during the yellowing period, because the fresh tobacco leaf cells are still in the stage of aerobic respiration and living metabolism, the self-heat generation amount of the tobacco leaves is large, resulting in excessive heat in the curing barn 2 and the dry bulb temperature exceeding the target value.

[0076] This embodiment is provided with a fresh air damper 19 and a moisture exhaust damper 110 that open and close synchronously, as Figure 5 shown. Taking the driving device as an electric push rod 112 as an example, the electric push rod 112 is installed on the partition 13. The electric push rod 112 can be located in the inner cavity 11 or in the outer cavity 12. Since the inner cavity 11 needs to heat the drying air, in order to prevent part of the heat from acting on the electric push rod 112, therefore, it is preferably to arrange the electric push rod 112 in the outer cavity 12. The output end of the electric push rod 112 is fixedly connected to the fresh air damper 19 and the moisture exhaust damper 110 respectively through a connecting member.

[0077] To increase the stability of the transmission, the connecting member is slidably arranged on the partition 13. The specific structure of the connecting member in this embodiment is not limited, and it can be a rod or a frame.

[0078] Furthermore, the output end of the electric push rod 112 is arranged vertically;

[0079] The connecting member includes a connecting cross bar 113. The middle of the connecting cross bar 113 is fixedly connected to the output end of the electric push rod 112. Both ends of the connecting cross bar 113 are respectively connected to a connecting vertical bar, and both ends of the connecting vertical bar are respectively fixedly connected to the fresh air damper 19 and the moisture exhaust damper 110.

[0080] When the heat in the baking chamber 2 is excessive and the dry bulb temperature is higher than the target value, the electric push rod 112 on the partition 13 can synchronously drive the fresh air damper 19 and the moisture exhaust damper 110 on the partition 13, while supplementing fresh air, discharging warm and humid air, and discharging the surplus heat in the baking chamber 2, so that the dry bulb temperature of the baking chamber 2 returns to the target value.

[0081] When the fresh air damper 19 and the moisture exhaust damper 110 are closed, the drying air flow circulates in a closed loop between the inner cavity 11 and the baking chamber 2, implementing the operation modes of internal dehumidification and internal heating, and external heat absorption and internal heating;

[0082] When the fresh air damper 19 and the moisture exhaust damper 110 are opened, the fresh air inlet 112 is at the position closest to the suction port where the first fan 16 is located and is in a negative pressure state. The ambient fresh air enters the outer cavity 12 from the outer cavity air inlet 121 at the top of the outer cavity 12, and after being heated by the first condenser 143 and the second condenser 153, is pressed into the baking chamber 2 by the first fan 16, making the baking chamber 2 in a slightly positive pressure state; at the same time, under the push of the first fan 16, the warm and humid return air in the baking chamber 2 enters the inner cavity 11 at a higher speed and dynamic pressure head. Due to the blocking effect of the high-efficiency internal dehumidification module for pre-cooling the incoming air and reheating the outgoing air in the inner cavity 11, the dynamic pressure head of the return air flow is converted into static pressure head, resulting in an increase in the air pressure at the moisture exhaust port 113. The warm and humid air flow gushes out of the moisture exhaust port 113 under the push of the pressure difference, completing the discharge of the surplus heat in the baking chamber 2 and making the dry and wet bulb temperatures of the baking chamber 2 return to the target value.

[0083] The advantages of the air path opening and closing combined drying device in this embodiment are as follows: Since the fresh air damper 19 and the moisture exhaust damper 110 are provided on the partition plate 13, the problem of exhausting the excess heat in the curing barn 2 during the yellowing period is solved. The heat pump subsystem no longer undertakes the functions of internal dehumidification and external heat exhaust, and the system returns to simplicity. The two heat pump subsystems of internal dehumidification and internal heating and external heat absorption and internal heating in the heat pump unit both return to a simple single-loop refrigeration system composed of a compressor, a condenser, a throttle valve, and an evaporator. The four-way valve, solenoid valve, check valve, and branch pipelines in the "one machine with three functions" system are removed, simplifying the fluorine circuit structure of the heat pump subsystem and greatly improving the system reliability.

[0084] Embodiment 2

[0085] The basic principle of this embodiment is the same as that of Embodiment 1, with the difference being that in Embodiment 1, the fresh air inlet 112, the moisture exhaust outlet 113, the fresh air damper 19, the moisture exhaust damper 110, and the driving device are all provided on the partition plate 13, while in this embodiment, the fresh air inlet 112, the moisture exhaust outlet 113, the fresh air damper 19, the moisture exhaust damper 110, and the driving device are all provided on the inner cavity side wall 1103. Please refer to Figure 20 , in addition to all the advantages of Embodiment 1, this embodiment also has the advantages of being convenient for maintenance and not competing with the outer cavity 12 for fresh air flow when supplementing fresh air.

[0086] Embodiment 3

[0087] Please refer to Figures 10 to 19 , on the basis of Embodiment 1 and Embodiment 2, this embodiment adds a moisture exhaust guide plate 111, that is, in the inner cavity 11, a moisture exhaust guide plate 111 is provided above the moisture exhaust outlet 113 and below the internal dehumidification module (that is, between the moisture exhaust outlet 113 and the internal dehumidification module). The moisture exhaust guide plate 111 is rotatably arranged on the partition plate 13 or the inner cavity side wall 1103. When the moisture exhaust damper 110 is opened, the moisture exhaust guide plate 111 unfolds; when the moisture exhaust damper 110 is closed, the moisture exhaust guide plate 111 retracts.

[0088] Preferably, when the fresh air inlet 112, the moisture exhaust port 113, the fresh air damper 19, the moisture exhaust damper 110 and the driving device are all arranged on the partition plate 13, the moisture exhaust guiding plate 111 is also arranged on the partition plate 13; when the fresh air inlet 112, the moisture exhaust port 113, the fresh air damper 19, the moisture exhaust damper 110 and the driving device are all arranged on the inner cavity side wall 1103, the moisture exhaust guiding plate 111 is also arranged on the inner cavity side wall 1103. Taking the moisture exhaust guiding plate 111 being rotatably arranged on the partition plate 13 as an example, when the drying air flow is in a closed-loop circulation, the fresh air damper 19 and the moisture exhaust damper 110 are closed synchronously, and the moisture exhaust guiding plate 111 is flipped to a position parallel to the partition plate 13 (i.e., attached to the partition plate 13, and at this time the moisture exhaust guiding plate 111 is in a retracted state), and the drying air flow circulates in the closed-loop channel formed by the upper and lower communication of the inner cavity 11 and the baking room 2; when the drying air flow is in a partial open-loop circulation, the fresh air damper 19 and the moisture exhaust damper 110 are opened synchronously, and the moisture exhaust guiding plate 111 is flipped to a position perpendicular to the partition plate 13 (at this time the moisture exhaust guiding plate 111 is in an open state), and the moisture exhaust guiding plate 111 and the bottom wall of the inner cavity 11 form a temporary channel together, intercepting the upward air flow and guiding it to be discharged to the outer cavity 12, promoting the replenishment of fresh air and the discharge of warm and humid air flow, so that the excess heat generated by the self-heating of the fresh tobacco leaves when the fresh tobacco leaf cells are still in the stage of aerobic respiration and living metabolism is discharged to the environment, and the dry and wet bulb temperatures of the baking room 2 return to the target values.

[0089] The moisture exhaust guiding plate 111 can be controlled manually or by a driving device. In this embodiment, the moisture exhaust guiding plate 111 and the moisture exhaust damper 110 move synchronously, that is, the moisture exhaust guiding plate 111, the moisture exhaust damper 110 and the fresh air damper 19 are driven by the same driving device.

[0090] In this embodiment, taking the driving device as the electric push rod 112 as an example, the output end of the electric push rod 112 is fixedly connected to the fresh air damper 19 and the moisture exhaust damper 110 respectively through connecting pieces.

[0091] Furthermore, the output end of the electric push rod 112 is arranged vertically;

[0092] The connecting piece includes a connecting cross bar 113. The middle of the connecting cross bar 113 is fixedly connected to the output end of the electric push rod 112. The two ends of the connecting cross bar 113 are respectively connected to a connecting vertical bar 114, and the two ends of the connecting vertical bar 114 are respectively fixedly connected to the fresh air damper 19 and the moisture exhaust damper 110.

[0093] The moisture exhaust guiding plate 111, the fresh air damper 19 and the moisture exhaust damper 110 can be arranged on the partition plate 13 at the same time, or can also be arranged on the side wall 1103 of the inner cavity 11 at the same time. The present invention does not make specific limitations on this. This embodiment takes being arranged on the partition plate 13 at the same time as an example.

[0094] The connecting member, the fresh air damper 19, and the dehumidification damper 110 are slidably disposed inside the partition 13 or on one side of the partition 13 located on the outer cavity 12 side, and no specific limitation is made in this embodiment. When the fresh air damper 19 and the dehumidification damper 110 are located on one side of the partition 13, openings are respectively provided at the upper ends of the fresh air damper 19 and the dehumidification damper 110 corresponding to the fresh air inlet 112 and the dehumidification outlet 113 of the partition 13. That is, when the openings are completely staggered from the fresh air inlet 112 and the dehumidification outlet 113 respectively, the fresh air damper 19 and the dehumidification damper 110 completely cover the fresh air inlet 112 and the dehumidification outlet 113 respectively. At this time, the fresh air inlet 112 and the dehumidification outlet 113 are in the closed state; when the openings overlap with the fresh air inlet 112 and the dehumidification outlet 113 respectively, at this time, the fresh air damper 19 and the dehumidification damper 110 can be completely staggered from the fresh air inlet 112 and the dehumidification outlet 113 respectively. At this time, the fresh air inlet 112 and the dehumidification outlet 113 are in the open state (when the openings are partially staggered from the fresh air inlet 112 and the dehumidification outlet 113 respectively, and the fresh air damper 19 and the dehumidification damper 110 are partially staggered from the fresh air inlet 112 and the dehumidification outlet 113 respectively, the fresh air inlet 112 and the dehumidification outlet 113 are also in the open state).

[0095] Please refer to Figures 10 to 15 , as an embodiment, the dehumidification guide plate 111 is hinged to the connecting member through a connecting rod 115. Specifically, one end of the connecting rod 115 is hinged to the upper end surface of the dehumidification guide plate 111, and the other end is hinged to the connecting cross bar 113. As the connecting cross bar 113 slides up and down, the connecting rod 115 pulls the dehumidification guide plate 111 towards the partition 13 (eventually making the dehumidification guide plate 111 fit on the partition 13) or pushes the dehumidification guide plate 111 in a direction away from the partition 13 (eventually making the dehumidification guide plate 111 perpendicular to the partition 13).

[0096] Please refer to Figures 16 to 19, as another embodiment, the moisture exhaust guiding plate 111 is connected to the moisture exhaust air door 110 through a connecting rope 120 and is connected to the partition plate 13 through an elastic member. In this embodiment, no specific limitation is imposed on the elastic member, such as it can be a spring 116, a compression spring, or other elastic components. Taking the spring 116 as an example. For instance: when the fresh air damper 19 and the moisture exhaust damper 110 close the fresh air inlet 112 and the moisture exhaust outlet 113 respectively, at this time, the moisture exhaust guiding plate 111 fits on the partition plate 13, that is, the moisture exhaust guiding plate 111 is retracted, and at this time, the output end of the electric push rod 112 is in the extended state. When the output end of the electric push rod 112 moves downward in a contracting motion, it drives the fresh air damper 19 and the moisture exhaust damper 110 to move downward. The fresh air damper 19 and the moisture exhaust damper 110 open the fresh air inlet 112 and the moisture exhaust outlet 113 respectively. At this time, during the downward rotation of the moisture exhaust damper 110, it pulls the moisture exhaust guiding plate 111 to rotate away from the partition plate 13. During the rotation of the moisture exhaust guiding plate 111, the spring 116 is stretched until the moisture exhaust guiding plate 111 is perpendicular to the partition plate 13. At this time, at the lower end of the moisture exhaust guiding plate 111, the moisture exhaust guiding plate 111 and the moisture exhaust damper 110 are tightened by the connecting rope 120; at the upper end of the moisture exhaust guiding plate 111, the moisture exhaust guiding plate 111 and the partition plate 13 are tightened by the spring 116, aiming to prevent the moisture exhaust guiding plate 111 from being accidentally retracted. Next, when the output end of the electric push rod 112 moves upward in an extending motion, the spring 116 pulls the moisture exhaust guiding plate 111 towards the partition plate 13 by its elastic force. At the same time, the moisture exhaust damper 110 moves upward and relaxes the connecting rope 120 until the moisture exhaust guiding plate 111 fits on the partition plate 13 (that is, the moisture exhaust guiding plate 111 is in the retracted state and the moisture exhaust guiding plate 111 is parallel to the partition plate 13).

[0097] Furthermore, the moisture exhaust guiding plate 111 is of a plate-like structure. One end of it is rotatably connected to the partition plate 13, and a middle short rod 118 is provided at the other end. This middle short rod 118 is perpendicular to the moisture exhaust guiding plate 111. One end of this middle short rod 118 is fixedly connected to the moisture exhaust guiding plate 111, and the other end is fixedly connected to a mounting short rod 119. The mounting short rod 119 is arranged in a direction away from the moisture exhaust guiding plate 111 and is perpendicular to the middle short rod 118. One end of the spring 116 is fixed on the partition plate 13, and the other end is fixed on the mounting short rod 119. When the moisture exhaust guiding plate 111 is retracted, the moisture exhaust guiding plate 111 is located between the partition plate 13 and the middle short rod 118. The middle short rod 118 is parallel to the partition plate 13, and the spring 116 is parallel to the middle short rod 118.

[0098] On the same side of the middle short rod 118, an arc-shaped sleeve 117 is fixedly provided on the moisture exhaust guiding plate 111. One end of the connecting rope 120 is fixed on the moisture exhaust damper 110, and the other end passes through the arc-shaped sleeve 117 and is fixed on the moisture exhaust guiding plate 111.

Claims

1. An air path opening and closing combined drying device, characterized in that It includes a heating and dehumidifying chamber, in which at least one inner cavity and at least one outer cavity are separated by a partition. The outer cavity communicates with the ambient air, and the inner cavity communicates with a baking chamber to form a circulation channel for the drying air flow. A fresh air inlet and a moisture exhaust outlet are also provided on the side wall or the partition of the inner cavity. An air inlet and an air outlet for communicating with the baking chamber are provided on the side wall of the inner cavity. The device further includes at least one inner dehumidifying and inner heating heat pump unit and at least one outer heat absorbing and inner heating heat pump unit. The first condenser of the outer heat absorbing and inner heating heat pump unit is arranged in the inner cavity corresponding to the air outlet, and the first evaporator of the inner dehumidifying and inner heating heat pump unit is arranged in the outer cavity. The second condenser of the inner dehumidifying and inner heating heat pump unit is arranged in the inner cavity corresponding to the air outlet, and the inner dehumidifying modules of the inner dehumidifying and inner heating heat pump unit are all arranged in the inner cavity and located between the air inlet and the air outlet. When the drying air flow is in a closed-loop circulation, the fresh air inlet and the moisture exhaust outlet are both closed, and the drying air flow circulates in the closed-loop circulation channel formed by the inner cavity and the baking chamber. The warm and humid return air in the baking chamber enters the inner cavity through the air inlet. A part of the warm and humid return air entering the inner cavity first passes through the inner dehumidifying module and then mixes with another part of the warm and humid return air, and then is heated by the first condenser and the second condenser and discharged to the baking chamber through the air outlet. When the drying air flow is in a partial open-loop circulation, the fresh air inlet and the moisture exhaust outlet are both opened. The ambient fresh air enters the inner cavity through the fresh air inlet, is heated by the first condenser and the second condenser and then discharged to the baking chamber through the air outlet. At the same time, the warm and humid return air in the baking chamber enters the inner cavity through the air inlet. A part of the warm and humid return air entering the inner cavity is discharged to the outside of the inner cavity through the moisture exhaust outlet, and another part of the warm and humid return air is heated by the first condenser and the second condenser and then discharged to the baking chamber through the air outlet.

2. The air circuit opening and closing combined drying device according to claim 1, characterized in that, A fresh air damper is provided on the fresh air inlet, and a moisture exhaust damper is provided on the moisture exhaust outlet. The fresh air damper and the moisture exhaust damper are opened and closed simultaneously by the same driving device.

3. The air path opening and closing combined drying device according to claim 2, wherein In the inner cavity, a moisture exhaust guide plate is arranged above the moisture exhaust outlet. The moisture exhaust guide plate is rotatably arranged on the partition or the side wall of the inner cavity. When the moisture exhaust damper is opened, the moisture exhaust guide plate unfolds; when the moisture exhaust damper is closed, the moisture exhaust guide plate retracts.

4. The air path opening and closing combined drying device according to claim 3, characterized in that, The moisture exhaust guide plate and the moisture exhaust damper are driven by the same driving device.

5. The air path opening and closing combined drying device according to claim 4, characterized in that, The driving device is an electric push rod. The electric push rod is installed on the side wall or the partition of the inner cavity. The output end of the electric push rod is fixedly connected to the fresh air damper and the moisture exhaust damper respectively through connecting pieces. The moisture exhaust guide plate is hinged to the connecting piece through a connecting rod; or, the moisture exhaust guide plate is connected to the moisture exhaust damper through a connecting rope, and the moisture exhaust guide plate is connected to the side wall or the partition of the inner cavity through an elastic member.

6. The air path opening and closing combined drying device according to claim 5, wherein The output end of the electric push rod is arranged vertically. The connecting member includes a connecting cross bar, the middle of the connecting cross bar is fixedly connected to the output end of the electric push rod, both ends of the connecting cross bar are respectively connected to a connecting vertical bar, and both ends of the connecting vertical bar are respectively fixedly connected to the fresh air damper and the dehumidification damper; When the dehumidification guide plate is hinged to the connecting member through a connecting rod, both ends of the connecting rod are respectively hinged to the connecting cross bar and the dehumidification guide plate.

7. The air path opening and closing combined drying device according to claim 1, characterized in that, The fresh air inlet is located above the dehumidification outlet, and the fresh air inlet is located below the first condenser and the second condenser, and the dehumidification outlet is located below the internal dehumidification module.

8. The air path opening and closing combined drying device according to claim 1, characterized in that, The internal dehumidification module includes a second evaporator.

9. The air path opening and closing combined drying device according to claim 8, wherein, The internal dehumidification module further includes a cross-flow heat exchanger, the cross-flow heat exchanger includes a hot fluid channel and a cold fluid channel, the air inlet of the second evaporator is communicated with the hot fluid channel of the cross-flow heat exchanger, and the air outlet of the second evaporator is communicated with the air inlet of the second condenser through the cold fluid channel of the cross-flow heat exchanger.

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