Drying system and control method thereof

Abstract

The application provides a drying system and a control method thereof. The drying system comprises a first drying room, a second drying room, a first heat exchange system, a second heat exchange system, a first bypass flow channel and a second bypass flow channel. According to the control method, the first heat exchange system and the second heat exchange system can heat the first drying room and the second drying room. The working states of the first heat exchange system and the second heat exchange system are controlled to adjust the temperature of the first drying room and the second drying room, so that the first drying room and the second drying room can independently perform three-stage drying, the drying efficiency of the drying system is effectively improved, the first bypass flow channel and the second bypass flow channel are arranged, the heat of the first heat exchange system and the second heat exchange system can be transferred and balanced according to the temperature of the first drying room and the second drying room, the heat exchange capacity of the outdoor unit corresponding to the first heat exchange system and the second heat exchange system is maximized, and the energy utilization rate of the drying system is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drying equipment, in particular to a drying system and a control method thereof. BACKGROUND

[0002] Tobacco is generally dried by a three-stage drying method. The three-stage drying method is divided into a first stage "yellowing stage", a second stage "color fixing stage", and a third stage "dry muscle stage" with respect to tobacco. The first stage is a low-temperature stage, at 40-42℃, and the water removal rate is 0.3-0.5% / h. The second stage is a medium-high temperature stage, at 53-55℃, and the water removal rate is 0.9-1.2% / h. The third stage is a high-temperature stage, at 60-75℃, and the water removal rate is 0.3-0.7% / h. In the prior art, the drying system generally uses each heat exchange system to be responsible for one drying room, so that each drying room is responsible for different drying stages of tobacco to ensure the drying effect of tobacco. However, in the whole drying process, the tobacco needs to be transferred between different drying rooms, which is complicated to operate, and there is still a problem of insufficient temperature rising rate and delayed dehumidification during the transfer process, which causes the tobacco to deteriorate or deform, resulting in the problems of complex tobacco drying process and unreliable drying effect in the prior art. SUMMARY

[0003] In order to solve the technical problems of complex tobacco drying process and unreliable drying effect in the prior art, a drying system and a control method thereof are provided, which use a first bypass flow channel and a second bypass flow channel to adjust the heat of a first heat exchange system and a second heat exchange system, so that the first drying room and the second drying room can directly perform three-stage drying to reduce the complexity of the drying process and improve the drying effect.

[0004] A drying system, comprising:

[0005] a first drying room;

[0006] a second drying room, the second drying room being sealed relative to the first drying room;

[0007] a first heat exchange system, the first heat exchange system comprising a first compressor, a first evaporator, a first throttling mechanism, and first and second condensers arranged in parallel between the first compressor and the first throttling mechanism, the first condenser being arranged in the first drying room, and the second condenser being arranged in the second drying room;

[0008] a second heat exchange system, the second heat exchange system comprising a second compressor, a second evaporator, a second throttling mechanism, and third and fourth condensers arranged in parallel between the second compressor and the second throttling mechanism, the third condenser being arranged in the first drying room, and the fourth condenser being arranged in the second drying room;

[0009] a first bypass passage, one end of which communicates between the first compressor and the first condenser, and the other end of which communicates between the first throttling mechanism and the first evaporator, and the refrigerant in the first bypass passage exchanges heat with the refrigerant between the second throttling mechanism and the second evaporator, and the refrigerant between the first condenser and the first throttling mechanism in turn;

[0010] a second bypass passage, one end of which communicates between the first compressor and the second condenser, and the other end of which communicates between the first throttling mechanism and the first evaporator, and the refrigerant in the second bypass passage exchanges heat with the refrigerant between the second throttling mechanism and the second evaporator, and the refrigerant between the second condenser and the first throttling mechanism in turn.

[0011] The drying system further comprises a first heat exchanger, which has a first heat exchange passage and a second heat exchange passage that exchange heat with each other, the first heat exchange passage is arranged between the second evaporator and the second throttling mechanism, one end of the second heat exchange passage communicates between the first compressor and the first condenser, and the other end of the second heat exchange passage communicates between the first throttling mechanism and the first evaporator, and the second heat exchange passage constitutes part of the first bypass passage.

[0012] The drying system further comprises a second heat exchanger, which has a third heat exchange passage and a fourth heat exchange passage that exchange heat with each other, the third heat exchange passage is arranged between the first condenser and the first throttling mechanism, the fourth heat exchange passage is arranged between the second heat exchange passage and the first evaporator, and the fourth heat exchange passage constitutes part of the first bypass passage.

[0013] The drying system further comprises a first bypass pipeline, which is connected in parallel to the second heat exchange passage, and the first bypass pipeline and the second heat exchange passage are switched to communicate.

[0014] The drying system further comprises a first three-way valve, an inlet of which communicates between the first compressor and the first condenser, a first outlet of which communicates with the second heat exchange passage, and a second outlet of which communicates with the first bypass pipeline.

[0015] The drying system further comprises a third heat exchanger having a fifth heat exchange channel and a sixth heat exchange channel which exchange heat with each other, the fifth heat exchange channel is arranged between the second evaporator and the second throttling mechanism, one end of the sixth heat exchange channel is communicated between the first compressor and the second condenser, the other end is communicated between the first throttling mechanism and the first evaporator, and the sixth heat exchange channel constitutes part of the second bypass channel.

[0016] The drying system further comprises a fourth heat exchanger having a seventh heat exchange channel and an eighth heat exchange channel which exchange heat with each other, the seventh heat exchange channel is arranged in series between the second condenser and the first throttling mechanism, the eighth heat exchange channel is arranged in series between the sixth heat exchange channel and the first evaporator, and the eighth heat exchange channel constitutes part of the second bypass channel.

[0017] The drying system further comprises a second bypass pipeline which is connected in parallel with the sixth heat exchange channel, and the second bypass pipeline is switched to communicate with the sixth heat exchange channel.

[0018] The drying system further comprises a second three-way valve, an inlet of the second three-way valve is communicated between the first compressor and the first condenser, a first outlet of the second three-way valve is communicated with the second heat exchange channel, and a second outlet of the second three-way valve is communicated with the first bypass pipeline.

[0019] The refrigerant of the first heat exchange system is R134a, and the refrigerant of the second heat exchange system is R410a.

[0020] A fan is arranged in the first curing barn, the first condenser is arranged between the third condenser and the fan, and the air outlet direction of the fan is away from the first condenser; and / or, a fan is arranged in the second curing barn, the second condenser is arranged between the fourth condenser and the fan, and the air outlet direction of the fan is away from the second condenser.

[0021] The drying system has a first drying mode and a second drying mode, the drying temperature of the second drying mode is higher than that of the first drying mode.

[0022] When the drying system is in the first drying mode, the first heat exchange system is stopped and the second heat exchange system is operated.

[0023] When the drying system is in the second drying mode, the second heat exchange system is stopped and the first heat exchange system is operated.

[0024] The first heat exchange system further includes an enthalpy-increasing pipeline, and the first bypass channel and / or the second bypass channel are connected to the first compressor through the enthalpy-increasing pipeline.

[0025] A first control mechanism is provided on the first bypass channel, and a second control mechanism is provided on the second bypass channel.

[0026] A control method for the above-mentioned drying system, the control method comprising:

[0027] Get the real-time temperature T1 of the first drying chamber and the real-time temperature T2 of the second drying chamber, and compare T1 with the target temperature Ta of the first drying chamber and T2 with the target temperature Tb of the second drying chamber.

[0028] If T1 > Ta, then open the first bypass channel;

[0029] If T2 > Tb, then open the second bypass channel.

[0030] After opening the first bypass channel if T1 > Ta, or opening the second bypass channel if T2 > Tb, the following steps are also included:

[0031] Obtain the operating status of the first and second heat exchange systems;

[0032] If the first heat exchange system is working and the second heat exchange system is shut down, reduce the operating frequency of the first compressor, reduce the opening of the first throttling mechanism, and start the second compressor.

[0033] If the first heat exchange system shuts down and the second heat exchange system operates, the operating frequency of the second compressor is reduced, the opening of the second throttling mechanism is decreased, and the first compressor is turned on.

[0034] If the first heat exchange system is operating and the second heat exchange system is shut down, after reducing the operating frequency of the first compressor, decreasing the opening of the first throttling mechanism, and starting the second compressor, the following steps are also included:

[0035] Obtain the temperature rise rate of the first drying chamber and the temperature rise rate of the second drying chamber;

[0036] If the temperature rise rate of the first drying chamber is ≥0 or the temperature rise rate of the second drying chamber is ≥0, then the operating frequency of the first compressor will continue to be reduced, and the opening of the first throttling mechanism will continue to be reduced.

[0037] The method of further reducing the operating frequency of the first compressor and further reducing the opening of the first throttling mechanism if the temperature rise rate of the first drying chamber is ≥0 or the temperature rise rate of the second drying chamber is ≥0 also includes:

[0038] Obtain the change in opening of the first throttling mechanism;

[0039] If the opening degree variation of the first throttling mechanism is greater than a first preset value, and the temperature rise rate of the first curing room and the temperature rise rate of the second curing room are determined again;

[0040] If the temperature rise rate of the first curing room is greater than or equal to 0 or the temperature rise rate of the second curing room is greater than or equal to 0, the opening degree of the first throttling mechanism remains unchanged, and the operating frequency of the second compressor is increased.

[0041] If the first heat exchange system is stopped and the second heat exchange system is operated, the operating frequency of the second compressor is reduced, the opening degree of the second throttling mechanism is reduced, and the first compressor is turned on, and further comprising:

[0042] The temperature rise rate of the first curing room is obtained;

[0043] If the temperature rise rate of the first curing room is greater than or equal to 0, the operating frequency of the second compressor is continuously reduced, and the opening degree of the second throttling mechanism is continuously reduced.

[0044] If the temperature rise rate of the first curing room is greater than or equal to 0, the operating frequency of the second compressor is continuously reduced, and the opening degree of the second throttling mechanism is continuously reduced.

[0045] The temperature rise rate of the second curing room is obtained;

[0046] If the real-time temperature of the second curing room is within the range of the target temperature of the second curing room-1℃ to the target temperature of the second curing room+1℃, and the temperature rise rate of the second curing room is within the range of-0.5℃ / h to 0.5℃ / h, the operating frequency of the first compressor and the opening degree of the first throttling mechanism (13) are maintained;

[0047] If the real-time temperature of the second curing room is within the range of the target temperature of the second curing room-1℃ to the target temperature of the second curing room+1℃, and the temperature rise rate of the second curing room is less than or equal to-0.5℃ / h, the opening degree of the first throttling mechanism is reduced.

[0048] If the first heat exchange system is operated and the second heat exchange system is stopped, the operating frequency of the first compressor is reduced, the opening degree of the first throttling mechanism is reduced, and the second compressor is turned on, and further comprising:

[0049] If T1>Ta, the fourth condenser is turned on and the third condenser is turned off;

[0050] If T2>Tb, the third condenser is turned on and the fourth condenser is turned off.

[0051] If the first heat exchange system is stopped and the second heat exchange system is operated, the operating frequency of the second compressor is reduced, the opening degree of the second throttling mechanism is reduced, and the first compressor is turned on, and further comprising:

[0052] If T1>Ta, the second condenser is turned on and the first condenser is turned off;

[0053] If T2>Tb, the first condenser is opened and the second condenser is closed.

[0054] The drying system and the control method thereof provided by the present application place the first condenser and the second condenser of the first heat exchange system in the first curing room and the second curing room respectively, and place the third condenser and the fourth condenser of the second heat exchange system in the first curing room and the second curing room respectively, so that the first heat exchange system and the second heat exchange system can heat the first curing room and the second curing room, and the temperature of the first curing room and the second curing room can be adjusted according to the working state of the first heat exchange system and the second heat exchange system, so that the first curing room and the second curing room can be independently dried in three stages. The problem that each curing room can only be dried in one stage in the prior art is solved, the drying process is simplified, the drying effect is improved, the drying efficiency of the drying system is effectively improved, and the heat exchange amount of the outdoor unit corresponding to the first heat exchange system and the second heat exchange system is maximized, and the energy utilization rate of the drying system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 The structure schematic diagram of the drying system provided by the embodiment of the present application is shown in the figure.

[0056] Figure 2 The structure schematic diagram of the first curing room of the drying system provided by the embodiment of the present application is shown in the figure.

[0057] Figure 3 The structure schematic diagram of the second curing room of the drying system provided by the embodiment of the present application is shown in the figure.

[0058] Figure 4 The control flow chart of the drying system provided by the embodiment of the present application is shown in the figure.

[0059] In the figure:

[0060] 11, first compressor; 12, first evaporator; 13, first throttling mechanism; 14, first condenser; 15, second condenser; 21, second compressor; 22, second evaporator; 23, second throttling mechanism; 24, third condenser; 25, fourth condenser; 31, first bypass flow channel; 32, second bypass flow channel; 16, first flow divider; 26, second flow divider; 4, first heat exchanger; 5, second heat exchanger; 61, first bypass pipeline; 7, third heat exchanger; 8, fourth heat exchanger; 62, second bypass pipeline; 27, first three-way valve; 28, second three-way valve; 9, fan. DETAILED DESCRIPTION

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention.

[0062] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0063] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate for the embodiments of the invention described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0064] It should be noted that in the description of this invention, terms such as "upper," "lower," "left," "right," "inner," and "outer," indicating directional or positional relationships, are based on the directional or positional relationships shown in the accompanying drawings. These are merely for ease of description and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation; therefore, they should not be construed as limitations on this invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0065] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection, an indirect connection through an intermediate medium, or a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] Tobacco is generally dried by three-stage drying, and the three-stage drying is divided into a first stage "yellowing stage", a second stage "color fixing stage", and a third stage "dry muscle stage" with respect to tobacco. The first stage is a low-temperature stage, at 40-42 DEG C, and the water removal rate is 0.3-0.5% / h, the second stage is a medium-high temperature stage, at 53-55 DEG C, and the water removal rate is 0.9-1.2% / h, and the third stage is a high-temperature stage, at 60-75 DEG C, and the water removal rate is 0.3-0.7% / h. In the prior art, the drying system generally uses each heat exchange system to be responsible for one curing barn, so that each curing barn is responsible for different drying stages of tobacco to ensure the drying effect of tobacco, but in the whole drying process, the tobacco needs to be transferred between different curing barns, the operation is complex, and in the transfer process, there is still a problem of insufficient temperature rising rate and delayed dehumidification, which causes the tobacco material to deteriorate or deform, resulting in the problems of complex tobacco drying process and unreliable drying effect in the prior art. Therefore, the present application provides a kind of Figure 1 and Figure 4The drying system comprises a first drying room, a second drying room which is sealed relative to the first drying room, a first heat exchange system which comprises a first compressor 11, a first evaporator 12, a first throttling mechanism 13, and a first condenser 14 and a second condenser 15 which are arranged in parallel between the first compressor 11 and the first throttling mechanism 13, the first condenser 14 is arranged in the first drying room, and the second condenser 15 is arranged in the second drying room, a second heat exchange system which comprises a second compressor 21, a second evaporator 22, a second throttling mechanism 23, and a third condenser 24 and a fourth condenser 25 which are arranged in parallel between the second compressor 21 and the second throttling mechanism 23, the third condenser 24 is arranged in the first drying room, and the fourth condenser 25 is arranged in the second drying room, a first bypass flow channel 31 which is communicated between the first compressor 11 and the first condenser 14 at one end and communicated between the first throttling mechanism 13 and the first evaporator 12 at the other end, and the refrigerant in the first bypass flow channel 31 exchanges heat with the refrigerant between the second throttling mechanism 23 and the second evaporator 22 and the refrigerant between the first condenser 14 and the first throttling mechanism 13 in sequence, and a second bypass flow channel 32 which is communicated between the first compressor 11 and the second condenser 15 at one end and communicated between the first throttling mechanism 13 and the first evaporator 12 at the other end, and the refrigerant in the second bypass flow channel 32 exchanges heat with the refrigerant between the second throttling mechanism 23 and the second evaporator 22 and the refrigerant between the second condenser 15 and the first throttling mechanism 13 in sequence.

[0067] When the drying system is working, according to the drying stage of the tobacco, the first heat exchange system or the second heat exchange system is selected to work. Taking the example that the first heat exchange system works and the second heat exchange system stops, at this time, the first condenser 14 can heat the first drying room, and the second condenser 15 can heat the second drying room, so as to ensure that the first drying room and the second drying room can dry the tobacco in one stage. Then, the temperature of the first condenser 14 and the second condenser 15 can be adjusted by adjusting the heat exchange amount of the first heat exchange system, or the second heat exchange system works and the first heat exchange system stops, so that the tobacco can be dried in the next stage. Without moving the tobacco, the tobacco can be dried in three stages in the same drying room, and the drying effect of the tobacco is effectively improved.

[0068] When the temperature of the first drying room is too high or the temperature of the second drying room is too high, the first heat exchange system and the second heat exchange system can be controlled to work, the heat exchange capacity of the heat exchange system working is reduced, and the heat exchange system not working is used to supplement the heat of the drying room which does not need to be cooled, so as to ensure that the first drying room and the second drying room can be reliably dried.

[0069] Taking the example that the first heat exchange system works and the second heat exchange system stops and the temperature of the first drying room is too high, at this time, the working frequency of the first compressor 11 in the first heat exchange system is reduced, and the opening of the first throttling mechanism 13 is reduced, so that the heating capacity of the first condenser 14 and the second condenser 15 is reduced, so that the temperature in the first drying room is gradually reduced. At the same time, due to the reduction of the heating capacity of the second condenser 15, the temperature in the second drying room will also be reduced and cannot be guaranteed to be reliable. At this time, the second heat exchange system starts to work, the third condenser 24 is closed, the fourth condenser 25 is opened, and the fourth condenser 25 is used to heat the second drying room to ensure the temperature in the second drying room. At the same time, the first bypass flow channel 31 is opened, and the refrigerant discharged from the first compressor 11 can exchange heat with the refrigerant in the second heat exchange system, so as to transfer the heat generated in the first heat exchange system to the second heat exchange system, and finally to the second drying room through the second heat exchange system. The heat generated by the outdoor units corresponding to the first heat exchange system and the second heat exchange system can be maximally utilized, and the heat between the first heat exchange system and the second heat exchange system can be transferred, so as to guarantee the reliable temperature in the second drying room. Moreover, since the first bypass flow channel 31 is connected between the first compressor 11 and the first condenser 14, at this time, the first bypass flow channel 31 will divert part of the refrigerant about to flow into the first condenser 14, so as to further reduce the heating capacity of the first condenser 14 and further reduce the temperature of the first drying room. In the whole process, the temperature of the first drying room will gradually decrease to the set target value, and the second drying room can be kept at the set target value under the joint action of the second condenser 15 and the fourth condenser 25, so as to realize the independent regulation and control of the temperature of the first drying room and the second drying room.

[0070] Or, for example, the first heat exchange system works and the second heat exchange system is shut down and the temperature of the second curing house is too high, at this time, the working frequency of the first compressor 11 in the first heat exchange system is reduced, and the opening of the first throttling mechanism 13 is reduced, so that the heating capacity of the first condenser 14 and the second condenser 15 is reduced, so that the temperature in the second curing house is gradually reduced, and at the same time, due to the reduction of the heating capacity of the first condenser 14, the temperature in the first curing house will also be reduced and cannot guarantee the reliable temperature, at this time, the second heat exchange system starts to work, the fourth condenser 25 is closed, the third condenser 24 is opened, and the third condenser 24 is used to heat the first curing house to ensure the temperature in the first curing house, and the second bypass flow channel 32 is opened, the refrigerant discharged by the first compressor 11 can be heat exchanged with the refrigerant in the second heat exchange system, so that the heat generated in the first heat exchange system is transferred to the second heat exchange system, and finally transferred to the first curing house through the second heat exchange system. The heat generated by the outdoor unit corresponding to the first heat exchange system and the second heat exchange system can be maximized, the heat between the first heat exchange system and the second heat exchange system can be transferred, the temperature in the first curing house is reliable, and due to the connection of the second bypass flow channel 32 between the first compressor 11 and the second condenser 15, at this time, the second bypass flow channel 32 will divert part of the refrigerant about to flow into the first condenser 14, thereby further reducing the heating capacity of the second condenser 15, and further reducing the temperature of the second curing house. In the whole process, the temperature of the second curing house will gradually decrease to the set target value, while the first curing house can be kept at the set target value under the joint action of the first condenser 14 and the third condenser 24, realizing the independent regulation and control of the temperature of the first curing house and the second curing house.

[0071] Or, for example, the second heat exchange system works and the first heat exchange system stops and the temperature of the first curing room is too high, at this time, the working frequency of the second compressor 21 in the second heat exchange system is reduced, and the opening of the second throttling mechanism 23 is reduced, so that the heating capacity of the third condenser 24 and the fourth condenser 25 is reduced, so that the temperature in the first curing room gradually decreases, and at the same time, due to the decrease of the heating capacity of the fourth condenser 25, the temperature in the second curing room also decreases and cannot guarantee the reliable temperature, at this time, the first heat exchange system starts to work, the second condenser 15 is opened and the first condenser 14 is closed, and the second condenser 15 is used to heat the second curing room to ensure the temperature in the second curing room, and the first bypass flow channel 31 is opened, so that the refrigerant discharged by the second compressor 21 can exchange heat with the refrigerant in the first heat exchange system, so that the heat generated in the second heat exchange system is transferred to the first heat exchange system, and finally transferred to the second curing room through the first heat exchange system. The heat generated by the outdoor unit corresponding to the first heat exchange system and the second heat exchange system can be maximized, and the heat between the first heat exchange system and the second heat exchange system can be transferred, so as to ensure the reliable temperature in the second curing room. In the whole process, the temperature of the first curing room gradually decreases to the set target value, and the second curing room can be kept at the set target value under the joint action of the second condenser 15 and the fourth condenser 25, realizing the independent regulation and control of the temperature of the first curing room and the second curing room.

[0072] Or, for example, the second heat exchange system works and the first heat exchange system stops and the temperature of the second curing room is too high, at this time, the working frequency of the second compressor 21 in the second heat exchange system is reduced, and the opening of the second throttling mechanism 23 is reduced, so that the heating capacity of the third condenser 24 and the fourth condenser 25 is reduced, so that the temperature in the second curing room gradually decreases, and at the same time, due to the decrease of the heating capacity of the third condenser 24, the temperature in the first curing room also decreases and cannot guarantee the reliable temperature, at this time, the first heat exchange system starts to work, the first condenser 14 is opened and the second condenser 15 is closed, and the first condenser 14 is used to heat the first curing room to ensure the temperature in the first curing room, and the second bypass flow channel 32 is opened, so that the refrigerant discharged by the second compressor 21 can exchange heat with the refrigerant in the first heat exchange system, so that the heat generated in the second heat exchange system is transferred to the first heat exchange system, and finally transferred to the first curing room through the first heat exchange system. The heat generated by the outdoor unit corresponding to the first heat exchange system and the second heat exchange system can be maximized, and the heat between the first heat exchange system and the second heat exchange system can be transferred, so as to ensure the reliable temperature in the first curing room. In the whole process, the temperature of the second curing room gradually decreases to the set target value, and the first curing room can be kept at the set target value under the joint action of the first condenser 14 and the third condenser 24, realizing the independent regulation and control of the temperature of the first curing room and the second curing room.

[0073] To realize the communication of the compressor with the two condensers and realize the control of whether the condensers work, the first heat exchange system further comprises a first flow divider 16, an inlet of the first flow divider 16 is communicated with the exhaust port of the first compressor 11, one outlet of the first flow divider 16 is communicated with the first condenser 14, another outlet of the first flow divider 16 is communicated with the second condenser 15, and the first flow divider 16 can control whether the exhaust of the first compressor 11 is sent to the first condenser 14 or whether it is sent to the second condenser 15, realizing the controllable work of the first condenser 14 and the controllable work of the second condenser 15, so as to realize the purpose of closing the first condenser 14 or closing the second condenser 15 in the foregoing. Similarly, the second heat exchange system further comprises a second flow divider 26, an inlet of the second flow divider 26 is communicated with the exhaust port of the second compressor 21, one outlet of the second flow divider 26 is communicated with the third condenser 24, another outlet of the second flow divider 26 is communicated with the fourth condenser 25, and the second flow divider 26 can control whether the exhaust of the second compressor 21 is sent to the third condenser 24 or whether it is sent to the fourth condenser 25, realizing the controllable work of the third condenser 24 and the controllable work of the fourth condenser 25, so as to realize the purpose of closing the third condenser 24 or closing the fourth condenser 25 in the foregoing.

[0074] Specifically, the drying system further comprises a first heat exchanger 4, the first heat exchanger 4 has a first heat exchange flow channel and a second heat exchange flow channel which exchange heat with each other, the first heat exchange flow channel is arranged between the second evaporator 22 and the second throttling mechanism 23, one end of the second heat exchange flow channel is communicated between the first compressor 11 and the first condenser 14, the other end is communicated between the first throttling mechanism 13 and the first evaporator 12, and the second heat exchange flow channel constitutes part of the first bypass flow channel 31. The refrigerant discharged by the first compressor 11 can flow into the second heat exchange flow channel and exchange heat with the refrigerant flowing to the second evaporator 22 through the second throttling mechanism 23 in the second heat exchange system, so that the heat of the first heat exchange system can be transmitted to the second heat exchange system, and then sent into the second curing barn through the second evaporator 22, the second compressor 21 in the second heat exchange system, so as to ensure the temperature of the second curing barn. Correspondingly, the heat generated by the outdoor unit can be maximized.

[0075] The drying system further comprises a second heat exchanger 5, which has a third heat exchange channel and a fourth heat exchange channel that exchange heat with each other, the third heat exchange channel is arranged between the first condenser 14 and the first throttling mechanism 13, the fourth heat exchange channel is arranged between the second heat exchange channel and the first evaporator 12, and the fourth heat exchange channel constitutes part of the first bypass channel 31. The refrigerant after heat exchange in the second heat exchange channel can flow into the fourth heat exchange channel to exchange heat with the refrigerant discharged from the first condenser 14 again, so as to ensure the state of the refrigerant flowing to the first evaporator 12 in the first bypass channel 31 is reliable, and further ensure the working of the first heat exchange system is reliable.

[0076] The drying system further comprises a first bypass pipeline 61, which is connected in parallel with the second heat exchange channel, and the first bypass pipeline 61 and the second heat exchange channel are switched to communicate. The first bypass pipeline 61 is used to short-circuit the second heat exchange channel, so that whether the refrigerant in the first bypass channel 31 enters the first heat exchanger 4 to exchange heat can be selected according to needs. When it is needed to transfer the heat in the first heat exchange system to the second heat exchange system, the refrigerant in the first heat exchange system can flow into the second heat exchange channel to exchange heat with the refrigerant in the first heat exchange channel, so as to realize the heat transfer. When it is not needed to transfer the heat in the first heat exchange system to the second heat exchange system, but it is needed to use the first bypass channel 31 to increase the enthalpy of the first compressor 11, the refrigerant in the first heat exchange system can directly flow to the first evaporator 12 through the first bypass pipeline 61, so as to realize the purpose of supplementing air and increasing the enthalpy of the first compressor 11. Preferably, the first heat exchange system further comprises an enthalpy increasing pipeline, the first bypass channel 31 communicates with the first compressor 11 through the enthalpy increasing pipeline, so as to ensure the effect of supplementing air and increasing the enthalpy of the first compressor 11. Preferably, the first bypass channel 31 is provided with a first control mechanism, which is used to control whether the refrigerant flows into the first bypass channel 31, so as to realize the control of whether the heat is transferred between the first heat exchange system and the second heat exchange system. In particular, when it is needed to supplement air and increase the enthalpy of the first compressor 11, the first control mechanism is used to control the flow of the first bypass channel 31, so as to ensure the supplementing air and increasing the enthalpy of the first compressor 11 is reliable. The enthalpy increasing mode can realize that the drying system is not affected by the environment temperature, and the drying ability is maintained in winter, so as to realize all-season drying, and make the drying system not limited to drying tobacco only, but can be used to dry other materials in the tobacco drying season, so as to expand the use range of the drying system.

[0077] In order to realize reliable switching of the first bypass pipeline 61 and the second heat exchange flow channel, the drying system further comprises a first three-way valve 27, an inlet of the first three-way valve 27 being in communication with the first compressor 11 and the first condenser 14, a first outlet of the first three-way valve 27 being in communication with the second heat exchange flow channel, and a second outlet of the first three-way valve 27 being in communication with the first bypass pipeline 61. When the first three-way valve 27 is opened, the inlet of the first three-way valve 27 and the first outlet of the first three-way valve 27 are in communication, and when the first three-way valve 27 is closed, the inlet of the first three-way valve 27 and the second outlet of the first three-way valve 27 are in communication.

[0078] The drying system further comprises a third heat exchanger 7, the third heat exchanger 7 having a fifth heat exchange flow channel and a sixth heat exchange flow channel in heat exchange with each other, the fifth heat exchange flow channel being arranged between the second evaporator 22 and the second throttling mechanism 23, one end of the sixth heat exchange flow channel being in communication with the first compressor 11 and the second condenser 15, the other end of the sixth heat exchange flow channel being in communication with the first throttling mechanism 13 and the first evaporator 12, and the sixth heat exchange flow channel constituting part of the second bypass flow channel 32. The refrigerant discharged by the first compressor 11 can flow into the sixth heat exchange flow channel and exchange heat with the refrigerant flowing to the second evaporator 22 through the second throttling mechanism 23 in the second heat exchange system, so that the heat of the first heat exchange system can be transmitted to the second heat exchange system, and then sent into the first drying room through the second evaporator 22 and the second compressor 21 in the second heat exchange system, so as to ensure the temperature of the first drying room, and the heat generated by the corresponding outdoor unit can be maximized.

[0079] The drying system further comprises a fourth heat exchanger 8, the fourth heat exchanger 8 having a seventh heat exchange flow channel and an eighth heat exchange flow channel in heat exchange with each other, the seventh heat exchange flow channel being in series between the second condenser 15 and the first throttling mechanism 13, the eighth heat exchange flow channel being in series between the sixth heat exchange flow channel and the first evaporator 12, and the eighth heat exchange flow channel constituting part of the second bypass flow channel 32. The refrigerant after heat exchange in the sixth heat exchange flow channel can flow into the eighth heat exchange flow channel to exchange heat with the refrigerant discharged by the second condenser 15 again, so as to ensure the state of the refrigerant flowing to the first evaporator 12 in the second bypass flow channel 32, and further ensure the reliable operation of the first heat exchange system.

[0080] The drying system further comprises a second bypass pipeline 62 which is connected in parallel with the sixth heat exchange channel and is switched to communicate with the sixth heat exchange channel. The sixth heat exchange channel is short-circuited by the second bypass pipeline 62, and the refrigerant in the second bypass channel 32 can be selected to flow into the third heat exchanger 7 for heat exchange according to the need. When it is needed to transfer the heat in the first heat exchange system to the second heat exchange system, the refrigerant in the first heat exchange system can flow into the sixth heat exchange channel and the fifth heat exchange channel for heat exchange, so as to realize the heat transfer. When it is not needed to transfer the heat in the first heat exchange system to the second heat exchange system, but it is needed to increase the enthalpy of the first compressor 11 by using the second bypass channel 32, the refrigerant in the first heat exchange system can directly flow to the first evaporator 12 through the second bypass pipeline 62, so as to realize the purpose of increasing the enthalpy of the first compressor 11 by air supplement. Preferably, the first heat exchange system further comprises an enthalpy increasing pipeline, and the second bypass channel 32 communicates with the first compressor 11 through the enthalpy increasing pipeline, so as to ensure the effect of increasing the enthalpy of the first compressor 11 by air supplement. Preferably, a second control mechanism is arranged on the second bypass channel 32, and the second control mechanism is used to control whether the refrigerant flows into the second bypass channel 32, so as to control whether the heat is transferred between the first heat exchange system and the second heat exchange system. In particular, when it is needed to increase the enthalpy of the first compressor 11 by air supplement, the flow of the second bypass channel 32 is controlled by the first control mechanism, so as to ensure the reliable increase of the enthalpy of the first compressor 11 by air supplement. The enthalpy increasing mode can realize that the drying system is not affected by the environment temperature, and the drying ability is maintained in winter, so as to realize all-season drying, and the drying system is not limited to drying tobacco, and other materials can be dried in the tobacco drying season, so as to expand the use range of the drying system.

[0081] In order to realize the reliable switching of the second bypass pipeline 62 and the sixth heat exchange channel, the drying system further comprises a second three-way valve 28, an inlet of the second three-way valve 28 communicates with the first compressor 11 and the first condenser 14, a first outlet of the second three-way valve 28 communicates with the second heat exchange channel, and a second outlet of the second three-way valve 28 communicates with the first bypass pipeline 61. When the second three-way valve 28 is opened, the inlet of the second three-way valve 28 and the first outlet of the second three-way valve 28 are communicated, and when the second three-way valve 28 is closed, the inlet of the second three-way valve 28 and the second outlet of the second three-way valve 28 are communicated.

[0082] Preferably, the refrigerant in the first heat exchange system is R134a, and the refrigerant in the second heat exchange system is R410a. That is, the first and second heat exchange systems use different refrigerants for heating, with R134a being a high-temperature refrigerant and R410a a low-temperature refrigerant. This allows the first and second heat exchange systems to meet the drying requirements at different stages of tobacco drying, eliminating the need to move the tobacco and allowing for direct drying throughout all stages, effectively improving the drying efficiency and effect. Specifically, the drying system has a first drying mode and a second drying mode, with the drying temperature in the second drying mode being higher than that in the first drying mode. When the drying system is in the first drying mode, the first heat exchange system shuts down while the second heat exchange system operates; when the drying system is in the second drying mode, the second heat exchange system shuts down while the first heat exchange system operates. In the three-stage tobacco drying process, the first and second stages are low- and medium-temperature stages, respectively. During these stages, the low-temperature refrigerant from the second heat exchange system is used to heat the curing barn by default; that is, the drying system switches to the first drying mode at this time. The third stage is a high-temperature stage, during which the high-temperature refrigerant from the first heat exchange system is used to heat the curing barn by default; that is, the drying system switches to the second drying mode at this time. Using different refrigerant systems for heating in different stages maximizes the drying efficiency of the drying system.

[0083] When the material needs to transition to a high-temperature stage after the medium-temperature baking stage, the system uses the high outlet air temperature as the control target. The second heat exchange system remains unchanged, while the first heat exchange system is turned on. The first heat exchange system regulates the outlet air temperature to reach the target value. Subsequently, the second heat exchange system gradually reduces its heating capacity, while the first heat exchange system gradually increases its heating capacity until the oven is fully heated to reach the target temperature and operates stably.

[0084] A fan 9 is installed in the first curing barn. The first condenser 14 is located between the third condenser 24 and the fan 9, and the fan 9 discharges air away from the first condenser 14. The fan 9 drives the gas in the first curing barn to flow sequentially through the third condenser 24 and the first condenser 14, ensuring reliable heating of the gas regardless of whether the first condenser 14 or the third condenser 24 is heating. After heating, the gas is sent to the tobacco for drying, thus achieving gas circulation within the first curing barn.

[0085] Similarly, the second drying room is provided with a fan 9, the second condenser 15 is arranged between the fourth condenser 25 and the fan 9, and the air outlet direction of the fan 9 is away from the second condenser 15. The fan 9 can drive the gas in the second drying room to flow through the fourth condenser 25 and the second condenser 15 in turn, so that the gas can be reliably heated whether the second condenser 15 or the fourth condenser 25 is heated, and after being heated, it can be sent to the tobacco for drying, realizing the circulation of the gas in the second drying room.

[0086] A control method of the above drying system, the control method comprises:

[0087] Obtaining the real-time temperature T1 of the first drying room and the real-time temperature T2 of the second drying room, and comparing T1 with the target temperature Ta of the first drying room, and comparing T2 with the target temperature Tb of the second drying room;

[0088] If T1>Ta, the first bypass flow channel 31 is opened, at this time, the heat of the first heat exchange system is transported into the second heat exchange system through the first bypass flow channel 31, preparing for the subsequent possible frequency adjustment of the first compressor 11, the opening adjustment of the first throttling mechanism 13, etc.

[0089] If T2>Tb, the second bypass flow channel 32 is opened, at this time, the heat of the first heat exchange system is transported into the second heat exchange system through the second bypass flow channel 32, preparing for the subsequent possible frequency adjustment of the first compressor 11, the opening adjustment of the first throttling mechanism 13, etc.

[0090] After T1>Ta, the first bypass flow channel 31 is opened, or after T2>Tb, the second bypass flow channel 32 is opened, further comprising:

[0091] Obtaining the working state of the first heat exchange system and the second heat exchange system;

[0092] If the first heat exchange system works and the second heat exchange system stops, the working frequency of the first compressor 11 is reduced, the opening of the first throttling mechanism 13 is reduced, the heating capacity of the first heat exchange system is reduced, and the second compressor 21 is opened, the heat of the first heat exchange system is transferred by the second heat exchange system, and the temperature in the drying room which does not need to be cooled is reliably ensured;

[0093] If the first heat exchange system stops and the second heat exchange system works, the working frequency of the second compressor 21 is reduced, the opening of the second throttling mechanism 23 is reduced, the heating capacity of the first heat exchange system is reduced, and the first compressor 11 is opened, the heat of the second heat exchange system is transferred by the first heat exchange system, and the temperature in the drying room which does not need to be cooled is reliably ensured.

[0094] If the first heat exchange system is working and the second heat exchange system is stopped, the working frequency of the first compressor 11 is reduced, the opening of the first throttling mechanism 13 is reduced, and the second compressor 21 is turned on.

[0095] The temperature rising rate of the first curing barn and the temperature rising rate of the second curing barn are obtained.

[0096] If the temperature rising rate of the first curing barn is greater than or equal to 0 or the temperature rising rate of the second curing barn is greater than or equal to 0, it indicates that the first curing barn or the second curing barn is still in a heated state at this time, and the heating capacity of the first heat exchange system needs to be continuously reduced, so the working frequency of the first compressor 11 is continuously reduced, and the opening of the first throttling mechanism 13 is continuously reduced.

[0097] In the step of continuously reducing the working frequency of the first compressor 11 and continuously reducing the opening of the first throttling mechanism 13, the method further comprises:

[0098] The change amount of the opening of the first throttling mechanism 13 is obtained.

[0099] If the change amount of the opening of the first throttling mechanism 13 is greater than a first preset value, and the temperature rising rate of the first curing barn and the temperature rising rate of the second curing barn are determined again.

[0100] If the temperature rising rate of the first curing barn is greater than or equal to 0 or the temperature rising rate of the second curing barn is greater than or equal to 0, it indicates that the adjustment ability of the first throttling mechanism 13 to the first heat exchange system is insufficient at this time, and the working frequency of the first compressor 11 needs to be adjusted to adjust the heat exchange capacity of the first heat exchange system, so the opening of the first throttling mechanism 13 remains unchanged, the working frequency of the second compressor 21 is increased, the balancing ability of the second heat exchange system to the heat in the first heat exchange system is increased, and the heating capacity of the first heat exchange system is further reduced, so as to achieve the purpose of reducing the temperature rising rate of the first curing barn or the temperature rising rate of the second curing barn.

[0101] Similarly, if the first heat exchange system is stopped and the second heat exchange system is working, the working frequency of the second compressor 21 is reduced, the opening of the second throttling mechanism 23 is reduced, and the first compressor 11 is turned on.

[0102] The temperature rising rate of the first curing barn is obtained.

[0103] If the temperature rising rate of the first curing barn is greater than or equal to 0, the working frequency of the second compressor 21 is continuously reduced, and the opening of the second throttling mechanism 23 is continuously reduced.

[0104] In the step of continuously reducing the working frequency of the second compressor 21 and continuously reducing the opening of the second throttling mechanism 23, the method further comprises:

[0105] acquiring a temperature rising rate of the second curing barn;

[0106] If the real-time temperature of the second curing barn is within the range of the target temperature of the second curing barn -1℃ to the target temperature of the second curing barn +1℃, and the temperature rising rate of the second curing barn is within the range of -0.5℃ / h to 0.5℃ / h, the operating frequency of the first compressor 11 and the opening degree of the first throttling mechanism 13 are kept unchanged;

[0107] If the real-time temperature of the second curing barn is within the range of the target temperature of the second curing barn -1℃ to the target temperature of the second curing barn +1℃, and the temperature rising rate of the second curing barn is ≤-0.5℃ / h, the opening degree of the first throttling mechanism 13 is reduced.

[0108] If the first heat exchange system is working and the second heat exchange system is stopped, the operating frequency of the first compressor 11 is reduced, the opening degree of the first throttling mechanism 13 is reduced, and the second compressor 21 is opened, further comprising:

[0109] If T1>Ta, the fourth condenser 25 is opened and the third condenser 24 is closed;

[0110] If T2>Tb, the third condenser 24 is opened and the fourth condenser 25 is closed.

[0111] If the first heat exchange system is stopped and the second heat exchange system is working, the operating frequency of the second compressor 21 is reduced, the opening degree of the second throttling mechanism 23 is reduced, and the first compressor 11 is opened, further comprising:

[0112] If T1>Ta, the second condenser 15 is opened and the first condenser 14 is closed;

[0113] If T2>Tb, the first condenser 14 is opened and the second condenser 15 is closed Embodiment 1

[0114] Taking the first heat exchange system working and the second heat exchange system stopping as an example;

[0115] When the temperature of the first curing barn is too high and the temperature of the second curing barn is normal, the running frequency of the first compressor 11 is slightly reduced, the opening degree of the first throttling mechanism 13 is reduced, the rotating speed of the fan 9 corresponding to the first evaporator 12 is kept unchanged, the first bypass flow channel 31 is opened, the second bypass flow channel 32 is kept closed, the first three-way valve 27 is opened, the second three-way valve 28 is kept closed, the second compressor 21 starts to work and keeps low-frequency operation, the fan 9 corresponding to the second evaporator 22 is kept stopped, and the second shunt 26 is only communicated with the fourth condenser 25, so that a part of the heat given by the first compressor 11 to the high-temperature cold coal is used for the second heat exchange system, the capacity of the first heat exchange system is reduced, the heat supply to the first condenser 14 is reduced, and the second heat exchange system is opened to provide heat for the second curing barn to maintain the temperature stable.

[0116] When the temperature of the first curing barn continues to rise and exceeds the first curing barn target temperature by 2℃, but the temperature rising rate of the first curing barn is ≤0, the drying system maintains the current state unchanged.

[0117] When the temperature of the first curing barn continues to rise and exceeds the first curing barn target temperature by 2℃, and the temperature rising rate of the first curing barn is ≥0, the running frequency of the first compressor 11 continues to be reduced, the opening degree of the first throttling mechanism 13 is adjusted to be appropriately smaller, so that the temperature rising rate is <0, and the rest of the components are maintained unchanged.

[0118] When the total amplitude of the smaller opening degree of the first throttling mechanism 13 is greater than 100B, but the temperature rising rate of the first curing barn is ≥0, the frequency of the second compressor 21 is increased, the first throttling mechanism 13 is no longer smaller, and the temperature rising rate is <0.

[0119] When the target temperature of the first curing barn < the real-time temperature of the first curing barn < the target temperature of the first curing barn + 2℃, and the temperature rising rate of the first curing barn is ≤0, the components of the drying system maintain the current state unchanged.

[0120] When the target temperature of the first curing barn - 2℃ < the real-time temperature of the first curing barn < the target temperature of the first curing barn, and the temperature rising rate of the first curing barn is <0, the working frequency of the first compressor 11 is increased, the opening degree of the first throttling mechanism 13 is continuously increased, so that the temperature rising rate is >0, and the rest of the components are maintained unchanged; when the total amplitude of the increased opening degree of the first throttling mechanism 13 is greater than 100B, and the temperature rising rate of the first curing barn is ≤0, the frequency of the second compressor 21 is reduced, the first throttling mechanism 13 is no longer increased, and the temperature rising rate is ≥0. Embodiment 2

[0121] Take the example that the second heat exchange system works and the first heat exchange system stops;

[0122] When the temperature of the first curing barn is too high and the temperature of the second curing barn is normal, the running frequency of the second compressor 21 is slightly reduced, the opening of the second throttling mechanism 23 is reduced, and the fan 9 corresponding to the second evaporator 22 keeps the rotating speed unchanged. The first bypass flow channel 31 is opened, the second bypass flow channel 32 is kept closed, the first three-way valve 27 is opened, the second three-way valve 28 is kept closed, the first compressor 11 starts to work and keeps low-frequency operation, and the fan 9 corresponding to the first evaporator 12 starts to operate at a low gear. At the same time, the first shunt 16 only communicates with the second condenser 15, and a part of the heat given by the second compressor 21 to the high-temperature cold coal is used for the first heat exchange system by reducing the refrigerant flow of the third condenser 24. The capacity of the second heat exchange system is reduced, the heat supply to the third condenser 24 is reduced, and the first heat exchange system is opened to provide heat for the second curing barn to maintain the temperature stable.

[0123] When the temperature of the first curing barn continues to rise and exceeds the target temperature of the first curing barn by 2℃, and the temperature rising rate of the first curing barn is ≤0, the second heat exchange system maintains the current state unchanged. At this time, the real-time temperature of the second curing barn is in the range of the target temperature of the second curing barn-1℃ to the target temperature of the second curing barn+1℃, and the temperature rising rate of the second curing barn is in the range of-0.5℃ / h to 0.5℃ / h, and the first heat exchange system keeps the current operating state; when the temperature rising rate of the second curing barn is ≤-0.5℃ / h, the first throtting mechanism 13 of the first heat exchange system is appropriately closed, and if the temperature rising rate of the second curing barn continues to decrease, the running frequency of the first compressor 11 is appropriately increased.

[0124] When the temperature of the first curing barn continues to rise and exceeds the target temperature of the first curing barn by 2℃, and the temperature rising rate of the first curing barn is >0, the second compressor 21 continues to reduce the frequency, the second throtting mechanism 23 is appropriately closed, the first compressor 11 increases the frequency, the first throtting mechanism 13 is appropriately opened, and the states of the remaining components are maintained unchanged. At this time, the real-time temperature of the second curing barn is in the range of the target temperature of the second curing barn-1℃ to the target temperature of the second curing barn+1℃, and the temperature rising rate of the second curing barn is in the range of-0.5℃ / h to 0.5℃ / h, and the first heat exchange system keeps the current operating state; when the temperature rising rate of the second curing barn is ≤-0.5℃ / h, the first throtting mechanism 13 is appropriately closed, and if the temperature rising rate of the second curing barn continues to decrease, the running frequency of the first compressor 11 is appropriately increased.

[0125] When the real-time temperature of the first curing barn is in the range of the target temperature of the first curing barn to the target temperature of the first curing barn+2℃, and the temperature rising rate of the first curing barn is ≤0, the components of the drying system maintain the current state unchanged.

[0126] The above embodiments only express several implementation manners of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the patent scope of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which are all within the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A drying system, characterized in that: include: First drying room; The second drying room is relatively sealed from the first drying room; The first heat exchange system includes a first compressor (11), a first evaporator (12), a first throttling mechanism (13), and a first condenser (14) and a second condenser (15) connected in parallel between the first compressor (11) and the first throttling mechanism (13). The first condenser (14) is located in the first drying oven, and the second condenser (15) is located in the second drying oven. The second heat exchange system includes a second compressor (21), a second evaporator (22), a second throttling mechanism (23), and a third condenser (24) and a fourth condenser (25) connected in parallel between the second compressor (21) and the second throttling mechanism (23). The third condenser (24) is located in the first drying oven, and the fourth condenser (25) is located in the second drying oven. The first bypass channel (31) has one end connected to the first compressor (11) and the first condenser (14), and the other end connected to the first throttling mechanism (13) and the first evaporator (12). The refrigerant in the first bypass channel (31) exchanges heat with the refrigerant between the second throttling mechanism (23) and the second evaporator (22), and between the first condenser (14) and the first throttling mechanism (13) in sequence. The second bypass channel (32) has one end connected to the first compressor (11) and the second condenser (15), and the other end connected to the first throttling mechanism (13) and the first evaporator (12). The refrigerant in the second bypass channel (32) exchanges heat with the refrigerant between the second throttling mechanism (23) and the second evaporator (22), and between the second condenser (15) and the first throttling mechanism (13) in sequence. The refrigerant for the first heat exchange system is R134a, and the refrigerant for the second heat exchange system is R410a; A first control mechanism is provided on the first bypass channel (31), and a second control mechanism is provided on the second bypass channel (32).

2. The drying system according to claim 1, characterized in that: The drying system further includes a first heat exchanger (4), which has a first heat exchange channel and a second heat exchange channel that exchange heat with each other. The first heat exchange channel is disposed between the second evaporator (22) and the second throttling mechanism (23). One end of the second heat exchange channel is connected to the first compressor (11) and the first condenser (14), and the other end is connected to the first throttling mechanism (13) and the first evaporator (12). The second heat exchange channel constitutes part of the first bypass channel (31).

3. The drying system according to claim 2, characterized in that: The drying system further includes a second heat exchanger (5), which has a third heat exchange channel and a fourth heat exchange channel that exchange heat with each other. The third heat exchange channel is disposed between the first condenser (14) and the first throttling mechanism (13), and the fourth heat exchange channel is disposed between the second heat exchange channel and the first evaporator (12). The fourth heat exchange channel constitutes part of the first bypass channel (31).

4. The drying system according to claim 2, characterized in that: The drying system further includes a first bypass pipe (61), which is connected in parallel to the second heat exchange channel, and the first bypass pipe (61) is switched to be connected to the second heat exchange channel.

5. The drying system according to claim 4, characterized in that: The drying system also includes a first three-way valve (27), the inlet of which is connected to the first compressor (11) and the first condenser (14), the first outlet of which is connected to the second heat exchange channel, and the second outlet of which is connected to the first bypass pipeline (61).

6. The drying system according to claim 4, characterized in that: The drying system further includes a third heat exchanger (7), which has a fifth heat exchange channel and a sixth heat exchange channel for mutual heat exchange. The fifth heat exchange channel is disposed between the second evaporator (22) and the second throttling mechanism (23). One end of the sixth heat exchange channel is connected between the first compressor (11) and the second condenser (15), and the other end is connected between the first throttling mechanism (13) and the first evaporator (12). The sixth heat exchange channel constitutes part of the second bypass channel (32).

7. The drying system according to claim 6, characterized in that: The drying system further includes a fourth heat exchanger (8), which has a seventh heat exchange channel and an eighth heat exchange channel that exchange heat with each other. The seventh heat exchange channel is connected in series between the second condenser (15) and the first throttling mechanism (13), and the eighth heat exchange channel is connected in series between the sixth heat exchange channel and the first evaporator (12). The eighth heat exchange channel constitutes part of the second bypass channel (32).

8. The drying system according to claim 6, characterized in that: The drying system also includes a second bypass pipe (62), which is connected in parallel to the sixth heat exchange channel and is switched to be connected to the sixth heat exchange channel.

9. The drying system according to claim 8, characterized in that: The drying system also includes a second three-way valve (28), the inlet of which is connected to the first compressor (11) and the first condenser (14), the first outlet of which is connected to the second heat exchange channel, and the second outlet of which is connected to the first bypass pipeline (61).

10. The drying system according to claim 1, characterized in that: A fan (9) is provided in the first drying chamber, and the first condenser (14) is located between the third condenser (24) and the fan (9), and the air outlet direction of the fan (9) is directed away from the first condenser (14); and / or, a fan (9) is provided in the second drying chamber, and the second condenser (15) is located between the fourth condenser (25) and the fan (9), and the air outlet direction of the fan (9) is directed away from the second condenser (15).

11. The drying system according to claim 1, characterized in that: The drying system has a first drying mode and a second drying mode, wherein the drying temperature of the second drying mode is higher than that of the first drying mode. When the drying system is in the first drying mode, the first heat exchange system stops and the second heat exchange system operates; When the drying system is in the second drying mode, the second heat exchange system stops while the first heat exchange system operates.

12. The drying system according to claim 1, characterized in that: The first heat exchange system further includes an enthalpy-increasing pipeline, through which the first bypass channel (31) and / or the second bypass channel (32) are connected to the first compressor (11).

13. A control method for a drying system according to any one of claims 1 to 12, characterized in that: The control method includes: Get the real-time temperature T1 of the first drying chamber and the real-time temperature T2 of the second drying chamber, and compare T1 with the target temperature Ta of the first drying chamber and T2 with the target temperature Tb of the second drying chamber. If T1 > Ta, then open the first bypass channel (31); If T2 > Tb, then open the second bypass channel (32).

14. The control method according to claim 13, characterized in that: After opening the first bypass channel (31) if T1 > Ta, or opening the second bypass channel (32) if T2 > Tb, the following is also included: Obtain the operating status of the first and second heat exchange systems; If the first heat exchange system is working and the second heat exchange system is shut down, the operating frequency of the first compressor (11) is reduced, the opening of the first throttling mechanism (13) is reduced, and the second compressor (21) is turned on. If the first heat exchange system stops and the second heat exchange system starts, the operating frequency of the second compressor (21) is reduced, the opening of the second throttling mechanism (23) is reduced, and the first compressor (11) is turned on.

15. The control method according to claim 14, characterized in that: If the first heat exchange system is working and the second heat exchange system is shut down, after reducing the operating frequency of the first compressor (11), reducing the opening of the first throttling mechanism (13), and opening the second compressor (21), the following steps are also included: Obtain the temperature rise rate of the first drying chamber and the temperature rise rate of the second drying chamber; If the temperature rise rate of the first drying chamber is ≥0 or the temperature rise rate of the second drying chamber is ≥0, then the operating frequency of the first compressor (11) will continue to be reduced, and the opening of the first throttling mechanism (13) will continue to be reduced.

16. The control method according to claim 15, characterized in that: In the process of further reducing the operating frequency of the first compressor (11) and further reducing the opening degree of the first throttling mechanism (13) if the temperature rise rate of the first drying chamber is ≥0 or the temperature rise rate of the second drying chamber is ≥0, the following further applies: Obtain the change in opening of the first throttling mechanism (13); If the opening change of the first throttling mechanism (13) is greater than the first preset value, the temperature rise rate of the first drying chamber and the temperature rise rate of the second drying chamber are determined again. If the temperature rise rate of the first drying chamber is ≥0 or the temperature rise rate of the second drying chamber is ≥0, the opening of the first throttling mechanism (13) remains unchanged, and the operating frequency of the second compressor (21) is increased.

17. The control method according to claim 14, characterized in that: If the first heat exchange system shuts down and the second heat exchange system operates, after reducing the operating frequency of the second compressor (21), decreasing the opening of the second throttling mechanism (23), and opening the first compressor (11), the following steps are also included: Obtain the temperature rise rate of the first drying chamber; If the temperature rise rate of the first drying chamber is ≥0, then the operating frequency of the second compressor (21) will continue to be reduced, and the opening of the second throttling mechanism (23) will continue to be reduced.

18. The control method according to claim 17, characterized in that: If the temperature rise rate of the first drying chamber is ≥0, then the operating frequency of the second compressor (21) is further reduced, and the opening of the second throttling mechanism (23) is further reduced, and the following steps are also included: Obtain the temperature rise rate of the second drying chamber; If the real-time temperature of the second drying chamber is within the range of -1℃ to +1℃ of the target temperature of the second drying chamber, and the temperature rise rate of the second drying chamber is within the range of -0.5℃ / h to 0.5℃ / h, then the operating frequency of the first compressor (11) and the opening degree of the first throttling mechanism (13) shall be maintained. If the real-time temperature of the second drying chamber is within the range of the target temperature of the second drying chamber -1℃ to the target temperature of the second drying chamber +1℃, and the temperature rise rate of the second drying chamber is < -0.5℃ / h, then reduce the opening of the first throttling mechanism (13).

19. The control method according to claim 14, characterized in that: If the first heat exchange system is working and the second heat exchange system is shut down, the operating frequency of the first compressor (11) is reduced, the opening of the first throttling mechanism (13) is reduced, and the second compressor (21) is turned on. This also includes: If T1 > Ta, then open the fourth condenser (25) and close the third condenser (24). If T2 > Tb, then open the third condenser (24) and close the fourth condenser (25).

20. The control method according to claim 14, characterized in that: If the first heat exchange system shuts down and the second heat exchange system operates, the operating frequency of the second compressor (21) is reduced, the opening of the second throttling mechanism (23) is decreased, and the first compressor (11) is opened. This also includes: If T1 > Ta, then open the second condenser (15) and close the first condenser (14). If T2 > Tb, then open the first condenser (14) and close the second condenser (15).

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