A multi-stage drying system

Abstract

The embodiment of the present invention provides a multi-stage drying system, which relates to the field of heat pump drying. The multi-stage drying system includes a return air duct, a supply air duct, a first drying area, a second drying area, a first compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling mechanism, a first fan and a second fan; the first heat exchanger is installed in the supply air duct or the return air duct, the second heat exchanger is installed in the return air duct, the first fan is used to make the first air pass through the second heat exchanger and the first heat exchanger in sequence, and send it into the first drying area; the second fan is used to make the first air in the first drying area and the second air in the second drying area perform non-contact heat exchange through the third heat exchanger, and the third heat exchanger is connected to the return air duct through the air duct to send the first air after heat exchange with the second air back to the return air duct. The embodiment of the present invention has the characteristics of high heat utilization rate and good energy saving effect.

Description

Technical Field

[0001] The invention relates to the field of heat pump drying, and in particular to a multi-stage drying system. Background Art

[0002] Existing heat pump drying systems can be divided into dehumidification type and non-dehumidification type:

[0003] The dehumidification type generally uses the evaporator in the refrigeration cycle to cool down a part of the air in the drying space, so that the moisture in the air condenses and achieves dehumidification of the air; the dehumidified air is further heated by the condenser and sent to the drying space, forming a compressor refrigeration cycle and an air treatment cycle, thereby continuously dehumidifying the air.

[0004] The non-dehumidification type mainly introduces part of the air in the drying space directly into the condenser side. The air is heated and then flows into the drying space. Compared with the dehumidification type, the air in the non-dehumidification type does not undergo the process of cooling and dehumidification.

[0005] The heat utilization rate of the dehumidification heat pump drying system in the prior art is low, resulting in energy waste. Summary of the invention

[0006] The object of the present invention is to provide a multi-stage drying system which has the characteristics of high heat utilization rate and good energy saving effect.

[0007] An embodiment of the present invention provides a multi-stage drying system, comprising a return air duct, an air supply duct, a first drying area, a second drying area, a first compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling mechanism, a first fan, and a second fan;

[0008] The temperature in the first drying area is higher than the temperature in the second drying area, and the return air duct is connected to the supply air duct;

[0009] The exhaust port of the first compressor is connected to the refrigerant inlet of the first heat exchanger, the refrigerant outlet of the first heat exchanger is connected to the inlet of the first throttling mechanism, the outlet of the first throttling mechanism is connected to the refrigerant inlet of the second heat exchanger, and the refrigerant outlet of the second heat exchanger is connected to the suction port of the first compressor;

[0010] The first heat exchanger is installed in the air supply duct or the return air duct, the second heat exchanger is installed in the return air duct, and the first fan is used to make the first air pass through the second heat exchanger and the first heat exchanger in sequence and send the first air into the first drying area;

[0011] The second fan is used to make the first air in the first drying area and the second air in the second drying area exchange heat without contact with each other through the third heat exchanger. The third heat exchanger is connected to the return air duct through an air duct to send the first air after heat exchange with the second air back to the return air duct.

[0012] In an optional embodiment, the multi-stage drying system also includes a first water receiving pan and a first drain pipe, the first water receiving pan is arranged below the second heat exchanger, and the first drain pipe is connected to the first water receiving pan for draining the water in the first water receiving pan to outside the air duct and the drying area.

[0013] In an optional embodiment, the multi-stage drying system further includes a second drain pipe, which is connected to the water path of the third heat exchanger and is used to drain condensed water generated by the third heat exchanger.

[0014] In an optional embodiment, the multi-stage drying system further includes a third fan, the third heat exchanger is connected to the return air duct via an air duct, and the third fan is disposed in the air duct to return the first air to the return air duct.

[0015] In an optional embodiment, the first drying area is connected to the return air duct through an air duct, and an air valve is provided on the air duct between the first drying area and the return air duct, and the air valve is used to open or close the air duct and to control the air volume of the first air from the first drying area entering the return air duct.

[0016] In an optional embodiment, the multi-stage drying system also includes a fourth heat exchanger and a fourth fan, and both are located outside the drying area. The fourth heat exchanger is used to exchange heat with the second air in the second drying area, and the fourth fan is used to make air flow through the fourth heat exchanger.

[0017] In an optional embodiment, the multi-stage drying system also includes a fifth heat exchanger, a sixth heat exchanger, a fifth fan, a second throttling mechanism and a second compressor, the fifth heat exchanger is used to exchange heat with the second air in the second drying area, the fifth fan is used to make air flow through the fifth heat exchanger, the fifth heat exchanger is connected to the second throttling mechanism, the second throttling mechanism is connected to the sixth heat exchanger, and the compressor is respectively connected to the fifth heat exchanger and the sixth heat exchanger.

[0018] In an optional embodiment, the second drying area is provided with air inlets and outlets for exchanging air with external air, and the air inlets and outlets are used to exchange air in the second drying area with external air.

[0019] In an optional embodiment, the multi-stage drying system also includes a third drying area, and the multi-stage drying system also includes a seventh heat exchanger and a sixth fan, the seventh heat exchanger is used to exchange heat between the air in the third drying area and the second air in the second drying area, and the sixth fan is used to make the air flow through the seventh heat exchanger.

[0020] In an optional embodiment, the multi-stage drying system also includes an eighth heat exchanger, which is connected to the third heat exchanger and is used to allow the first air to exchange heat with the air in the third drying area after exchanging heat with the second air, and to return the first air to the return air duct.

[0021] In an optional embodiment, the multi-stage drying system further includes 1st to Nth multi-stage drying areas, and the temperature of the i+1th multi-stage drying area is less than the temperature of the ith multi-stage drying area, wherein i is a positive integer, and i ranges from 1 to N-1;

[0022] The multi-stage drying system further comprises first to N multi-stage heat exchange components, each of which can prevent two gases flowing through from contacting each other and exchange heat between the two gases;

[0023] When N=1, the 1st to Nth multi-stage heat exchange components are first multi-stage heat exchange components, and the first multi-stage heat exchange components are respectively connected with the second drying area and the first multi-stage drying area through air ducts, so as to exchange heat with the gas in the second drying area without contact;

[0024] When N≥2, the j-th multi-stage heat exchange component is connected to the j-th multi-stage drying area and the j-1-th multi-stage drying area through air ducts, respectively, so as to enable the gas in the j-th multi-stage drying area to exchange heat with the gas in the j-1-th multi-stage drying area without contact, wherein j is a positive integer and the value of j ranges from 2 to N.

[0025] In an optional embodiment, the multi-stage drying system also includes a transmission mechanism and a partitioning device, wherein the transmission mechanism is transmission-connected to the partitioning device and is used to drive the partitioning device to move in the drying room to divide the drying room into at least two drying areas, wherein the at least two drying areas include the first drying area and the second drying area.

[0026] The multi-stage drying system provided by the embodiment of the present invention includes a return air duct, a supply air duct, a first drying area, a second drying area, a first compressor, a first heat exchanger, a second heat exchanger, a third heat exchanger, a first throttling mechanism, a first fan and a second fan; the first fan is used to make the first air pass through the second heat exchanger and the first heat exchanger in sequence and be sent into the first drying area; the second fan is used to make the first air in the first drying area and the second air in the second drying area perform non-contact heat exchange through the third heat exchanger, and the third heat exchanger is connected to the return air duct through the duct to send the first air after heat exchange with the second air back to the return air duct. That is to say, after heat exchange with the first drying area, the first air can also exchange heat with the second air in the second drying area. Since the temperature of the first drying area is greater than the temperature of the second drying area, the temperature of the first air when entering the first drying area is greater than the temperature of the first drying area; after the first air enters the first drying area, it exchanges heat with the original air in the first drying area, thereby drying the objects to be dried in the first drying area. Furthermore, the first air in the first drying area is guided to the third heat exchanger, and the first air and the second air in the second drying area are heat exchanged through the third heat exchanger, so that the gas heat in the first drying area is used to dry the objects to be dried in the second drying area; thereafter, after heat exchange with the gas in the second drying area, the first air returns to the return air duct and the supply air duct, and after passing through the second heat exchanger and the first heat exchanger, enters the next heat exchange cycle, thereby achieving good heat utilization. The embodiment of the present invention has the characteristics of high heat utilization rate and good energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of the structure of a multi-stage drying system provided by an embodiment of the present invention;

[0029] Figure 2 Another structural schematic diagram of a multi-stage drying system provided by an embodiment of the present invention;

[0030] Figure 3 The multi-stage drying system provided by the embodiment of the present invention includes a schematic diagram of the structure of a third fan;

[0031] Figure 4 A schematic diagram of the structure of a multi-stage drying system including a fourth heat exchanger and a fourth fan provided by an embodiment of the present invention;

[0032] Figure 5 for Figure 4 A schematic diagram of the structure of a multi-stage drying system using another heat exchange structure;

[0033] Figure 6 A schematic diagram of the structure of the multi-stage drying system provided by an embodiment of the present invention includes a third drying area;

[0034] Figure 7 for Figure 6 The multi-stage drying system includes a schematic diagram of the structure of the eighth heat exchanger;

[0035] Figure 8 for Figure 7 Another structural schematic diagram of the multi-stage drying system in FIG.

[0036] Icons: 100-multi-stage drying system; 101-return air duct; 102-supply air duct; 103-first drying area; 104-second drying area; 105-first compressor; 106-first heat exchanger; 107-second heat exchanger; 108-third heat exchanger; 109-first throttling mechanism; 110-first fan; 111-second fan; 112-first water tray; 113-first drain pipe; 115-second drain pipe; 116-third fan; 117-fourth heat exchanger; 118-fourth fan; 119-fifth heat exchanger; 120-sixth heat exchanger; 121-fifth fan; 122-second throttling mechanism; 123-second compressor; 124-third drying area; 125-seventh heat exchanger; 126-sixth fan; 127-eighth heat exchanger. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0042] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] See also Figure 1 The embodiment of the present invention provides a multi-stage drying system 100. The multi-stage drying system 100 can be used to dry objects to be dried, and has the characteristics of high heat utilization rate and good energy saving effect. The objects to be dried can be crops, medicinal materials, etc.

[0044] In the embodiment of the present invention, the multi-stage drying system 100 includes a return air duct 101, an air supply duct 102, a first drying area 103, a second drying area 104, a first compressor 105, a first heat exchanger 106, a second heat exchanger 107, a third heat exchanger 108, a first throttling mechanism 109, a first fan 110 and a second fan 111; the temperature in the first drying area 103 is higher than the temperature in the second drying area 104, and the return air duct 101 is connected to the air supply duct 102; the exhaust port of the first compressor 105 is connected to the refrigerant inlet of the first heat exchanger 106, the refrigerant outlet of the first heat exchanger 106 is connected to the inlet of the first throttling mechanism 109, and the outlet of the first throttling mechanism 109 is connected to the throttling mechanism of the second heat exchanger 107. The refrigerant inlet is connected, and the refrigerant outlet of the second heat exchanger 107 is connected to the air intake of the first compressor 105; the first heat exchanger 106 is installed in the supply air duct 102 or the return air duct 101, and the second heat exchanger 107 is installed in the return air duct 101. The first fan 110 is used to make the first air pass through the second heat exchanger 107 and the first heat exchanger 106 in sequence and send it into the first drying area 103; the second fan 111 is used to make the first air in the first drying area 103 and the second air in the second drying area 104 pass through the third heat exchanger 108 so that the first air and the second air do not contact each other. The third heat exchanger 108 is connected to the return air duct 101 through the air duct to send the first air after heat exchange with the second air back to the return air duct 101.

[0045] It should be understood that, in the heat exchange air duct, the first air exchanges heat with the second heat exchanger 107 and the first heat exchanger 106, and then enters the first drying area 103 to dry the objects to be dried in the first drying area 103; at the same time, the third heat exchanger 108 can realize heat exchange between the first air in the first drying area 103 and the second air in the second drying area 104 (where the first air and the second air are not in contact), so that the temperature of the second air in the second drying area 104 is increased, thereby drying the objects to be dried in the second drying area 104. The temperature of the first air in the first drying area 103 is greater than the temperature of the second air in the second drying area 104. After the first air completes heat exchange in the first drying area 103, its temperature is higher than the temperature of the second air in the second drying area 104. The first air and the second air realize heat exchange in the third heat exchanger 108, which is conducive to improving the heat utilization rate of the first air.

[0046] It should be noted that the first air and the second air perform non-contact heat exchange in the third heat exchanger 108, and the third heat exchanger 108 may have two heat exchange pipelines and a heat exchanger between the two heat exchange pipelines, and the first air and the second air flow through one of the two heat exchange pipelines respectively, and perform heat exchange through the heat exchanger therebetween. Of course, it is not limited to this, and the third heat exchanger 108 may also have other structural forms.

[0047] At the same time, it should also be noted that, in the embodiment of the present invention, the air supply duct 102 is connected to the first drying area 103, and the first air in the third heat exchanger 108 returns to the return air duct 101 after heat exchange with the second air, wherein the air supply port of the air supply duct 102 is connected to the first drying area 103, and the return air port of the return air duct 101 is connected to the pipeline of the third heat exchanger 108. The first fan 110 is used to make the gas flow from the return air duct 101 to the air supply duct 102, and send the air into the first drying area 103; the second fan 111 is used to make the second air pass through the third heat exchanger 108 for heat exchange.

[0048] It should be noted that the above scheme uses multi-stage drying to achieve more energy saving. For example, in the refrigeration cycle formed by the first compressor 105, the first heat exchanger 106, the second heat exchanger 107 and the first throttling mechanism 109, the cooling capacity produced by the second heat exchanger 107 is Q1, and the cooling capacity provided by the heat exchange between the air in the first drying area 103 and the third heat exchanger 108 is Q2. Then, the sum of the cooling capacity processed for part of the air in the first drying area 103 is Q1+Q2, that is, the cooling capacity of Q1+Q2 can be used to cool the air, so that the air condenses more water; at the same time, the heat Q2 is provided to the second drying area 104, so that the second drying area 104 can more easily evaporate the water of the dried object into the air, so that the water removal capacity can be greatly increased under the condition of basically the same power consumption (or a small increase in power), the overall efficiency is improved, and the water discharge efficiency of the dried object in the second drying area 104 is also improved, realizing multi-stage energy utilization.

[0049] In an optional embodiment, the multi-stage drying system 100 also includes a first water receiving tray 112 and a first drain pipe 113. The first water receiving tray 112 is arranged below the second heat exchanger 107. The first drain pipe 113 is connected to the first water receiving tray 112 for draining the water in the first water receiving tray 112 to outside the air duct and the drying area.

[0050] The first water receiving pan 112 is used to receive the condensed water generated by the second heat exchanger 107, and the first drain pipe 113 can drain the condensed water. Optionally, a water pump can be added to the first drain pipe 113 to drain the water in the first water receiving pan 112 through the first drain pipe 113; of course, gravity can also be used to drain the water in the first water receiving pan 112 through the first drain pipe 113 to outside the heat exchange air duct and the drying area.

[0051] In an optional embodiment, the multi-stage drying system 100 also includes a second drain pipe 115, which is connected to the third heat exchanger 108 or to the air duct around the third heat exchanger 108, and is used to discharge the condensed water generated by the third heat exchanger 108 to outside the air duct and the drying area.

[0052] The third heat exchanger 108 generates condensed water when performing heat exchange, usually on the side with higher temperature, and the second drain pipe 115 can discharge the condensed water. Optionally, a water pump can be added to the second drain pipe 115 to discharge the condensed water through the second drain pipe 115; of course, gravity can also be used to drain the condensed water through the second drain pipe 115 to outside the heat exchange air duct and the drying area.

[0053] See also Figure 2 In an optional embodiment, the third heat exchanger 108 and the second fan 111 can be located in the second drying area 104 or outside the drying area. Figure 1 As shown, the third heat exchanger 108 is located in the second drying area 104, and the first air and the second air perform heat exchange in the second drying area 104; Figure 2 As shown, the third heat exchanger 108 is located outside the second drying area 104, and the first air and the second air exchange heat outside the second drying area 104. Of course, the third heat exchanger 108 can also be arranged in the first drying area 103, that is, the first air and the second air can exchange heat in the first drying area 103.

[0054] See also Figure 3 In an optional embodiment, the multi-stage drying system 100 further includes a third fan 116 , the third heat exchanger 108 is connected to the return air duct 101 through the air duct, and the third fan 116 is disposed in the air duct to send the first air back to the return air duct 101 .

[0055] Optionally, the first drying area 103 is connected to the return air duct 101 so that the first air in the first drying area 103 is directly sent back to the return air duct 101 and the supply air duct 102, and heat is exchanged through the second heat exchanger 107 and the first heat exchanger 106; that is, a part of the first air in the second drying area 104 can be directly returned to the return air duct 101 and the supply air duct 102 without heat exchange with the second air.

[0056] Further, the first drying area 103 is connected to the second heat exchanger 107 through an air duct, and is used to guide the first air in the first drying area 103 to the second heat exchanger 107. Further, the first drying area 103 is connected to the return air duct 101 through the air duct, and an air valve is provided on the air duct between the first drying area 103 and the return air duct 101, and the air valve is used to open or close the air duct and to control the air volume of the first air from the first drying area 103 entering the return air duct 101.

[0057] It should be understood that the air valve provided on the connecting pipeline can be used to open or close the connecting pipeline, thereby controlling whether the first air of the first drying area 103 enters the second heat exchanger 107 and controlling the air volume entering the second heat exchanger 107 .

[0058] See also Figure 4 In an optional embodiment, the multi-stage drying system 100 also includes a fourth heat exchanger 117 and a fourth fan 118, and both are located outside the drying area. The fourth heat exchanger 117 is used to exchange heat with the second air in the second drying area 104, and the fourth fan 118 is used to make the air flow through the fourth heat exchanger 117 to achieve heat exchange between the air and the fourth heat exchanger 117.

[0059] It should be noted that by adding the fourth heat exchanger 117, the air in the second drying area 104 can exchange heat with the outside, and the air from the second drying area 104 can be directly cooled and condensed to remove moisture after passing through the fourth heat exchanger 117, thereby achieving the purpose of dehumidification. In this case, without adding an additional refrigeration cycle, a small amount of energy is consumed, more water removal is achieved, and the overall efficiency is improved.

[0060] See also Figure 5In an optional embodiment, the multi-stage drying system 100 also includes a fifth heat exchanger 119, a sixth heat exchanger 120, a fifth fan 121, a second throttling mechanism 122 and a second compressor 123. The fifth heat exchanger 119 is used to exchange heat with the second air in the second drying area 104. The fifth fan 121 is used to allow air to flow through the fifth heat exchanger 119, thereby exchanging heat between the air and the fifth heat exchanger 119; the fifth heat exchanger 119 is connected to the second throttling mechanism 122, the second throttling mechanism 122 is connected to the sixth heat exchanger 120, and the compressors are respectively connected to the fifth heat exchanger 119 and the sixth heat exchanger 120.

[0061] It should be noted that, through another compression refrigeration cycle, the moisture in the air of the second drying area 104 is more easily precipitated. By adopting this compression refrigeration cycle, the second drying area 104 can be dehydrated in more outdoor environments, reducing environmental requirements and restrictions.

[0062] In an optional embodiment, the second drying area 104 is provided with air inlets and outlets for exchanging air with the outside air, and the air inlets and outlets are used to exchange the air in the second drying area 104 with the outside air.

[0063] See also Figure 6 In an optional embodiment, the multi-stage drying system 100 also includes a third drying area 124, and the multi-stage drying system 100 also includes a seventh heat exchanger 125 and a sixth fan 126, the seventh heat exchanger 125 is used to exchange heat between the air in the third drying area 124 and the second air in the second drying area 104, and the sixth fan 126 is used to make the air flow through the seventh heat exchanger 125.

[0064] It should be noted that by adding the third drying area 124 for air heat exchange with the second drying area 104, the multi-stage drying method is expanded to achieve cascade utilization of energy.

[0065] Alternatively, if Figure 6 As shown, a drain pipe can be connected to the seventh heat exchanger 125 or the air duct nearby, and the drain pipe can discharge the condensed water generated by the seventh heat exchanger 125.

[0066] See also Figure 7 In an optional embodiment, the multi-stage drying system 100 also includes an eighth heat exchanger 127, which is connected to the third heat exchanger 108 and is used to allow the first air to exchange heat with the air in the third drying area 124 after exchanging heat with the second air, and then return to the return air duct 101.

[0067] It should be noted that the air in the first drying area 103 undergoes heat exchange in the third heat exchanger 108 and then in 107 , and then in 107 again, so that the air undergoes more heat exchange and more condensed water is precipitated.

[0068] Alternatively, if Figure 6 As shown, a drain pipe can be connected to the eighth heat exchanger 127 or the air duct nearby, and the drain pipe can discharge the condensed water generated by the eighth heat exchanger 127.

[0069] Optionally, see Figure 7 and Figure 8 The eighth heat exchanger 127 may be located in the third drying area 124, or outside the third drying area 124. Figure 7 In the embodiment, the eighth heat exchanger 127 may be located in the third drying area 124; Figure 8 In the embodiment, the eighth heat exchanger 127 is located outside the third drying area 124 .

[0070] It should be understood that, in an optional embodiment, the multi-stage drying system 100 may further include an Nth drying area, wherein the temperature of the Nth drying area is lower than the temperature of the N-1th drying area, and the multi-stage drying system 100 further includes a heat exchanger for exchanging heat between the Nth drying area and the N-1th drying area, and a drain pipe for draining condensed water generated by the heat exchanger. Wherein N is a positive integer greater than or equal to 3.

[0071] In an optional embodiment, the multi-stage drying system 100 further includes 1st to Nth multi-stage drying areas, and the temperature of the i+1th multi-stage drying area is lower than the temperature of the ith multi-stage drying area, wherein i is a positive integer, and i ranges from 1 to N-1; the multi-stage drying system 100 further includes 1st to Nth multi-stage heat exchange components, and the 1st to Nth multi-stage heat exchange components can prevent the two gases flowing through from contacting each other and exchange heat between the two gases, wherein N is a positive integer;

[0072] When N=1, the 1st to Nth multi-stage heat exchange components are the first multi-stage heat exchange components, which are respectively connected with the second drying area 104 and the first multi-stage drying area through the air duct, so as to exchange heat with the gas in the second drying area 104 without contact with the gas in the first multi-stage drying area;

[0073] When N≥2, the j-th multi-stage heat exchange component is connected to the j-th multi-stage drying area and the j-1-th multi-stage drying area through air ducts, respectively, so as to enable the gas in the j-th multi-stage drying area to exchange heat with the gas in the j-1-th multi-stage drying area without contact, wherein j is a positive integer and the value of j ranges from 2 to N.

[0074] It should be noted that, according to the multi-stage heat exchange form, heat exchange in N drying areas is achieved, so that water is analyzed from the air flowing through the corresponding heat exchanger, and the water needs to be discharged outside the drying area.

[0075] Furthermore, the Nth drying area is selectively connected to the outside world so that the air in the Nth drying area can be exchanged with the outside world. That is to say, for the multi-stage drying system 100, the last drying area can be connected to the outside world to achieve exchange with the outside world. In this embodiment, the Nth drying area achieves direct air exchange with the outside world, and the high-humidity air in the drying area is discharged to the outside environment. At the same time, the low-humidity air in the outside world can also be introduced into the drying area.

[0076] In an optional embodiment, the multi-stage drying system 100 may further include a transmission mechanism and a partitioning device, wherein the transmission mechanism is in transmission connection with the partitioning device and is used to drive the partitioning device to move in the drying room to divide the drying room into at least two drying areas, wherein the at least two drying areas include a first drying area 103 and a second drying area 104. The transmission mechanism and the partitioning device may be used to adjust the area range of the drying area, which is conducive to the flexible use of the drying area to dry the objects to be dried.

[0077] It should be noted that, in one drying room, by using certain partitioning devices, the operation conditions of at least two drying areas can be achieved.

[0078] A multi-stage drying system 100 provided in an embodiment of the present invention: the multi-stage drying system 100 includes a return air duct 101, an air supply duct 102, a first drying area 103, a second drying area 104, a first compressor 105, a first heat exchanger 106, a second heat exchanger 107, a third heat exchanger 108, a first throttling mechanism 109, a first fan 110 and a second fan 111; the first fan 110 is used to allow the first air to pass through the second heat exchanger 107 and the first heat exchanger 106 in sequence and be sent into the first drying area 103; the second fan 111 is used to allow the first air in the first drying area 103 and the second air in the second drying area 104 to perform non-contact heat exchange through the third heat exchanger 108, and the third heat exchanger 108 is connected to the return air duct 101 through the air duct to send the first air after heat exchange with the second air back to the return air duct 101. That is to say, after exchanging heat with the first drying area 103, the first air can also exchange heat with the second air in the second drying area 104 to achieve good heat utilization. The embodiment of the present invention has the characteristics of high heat utilization rate and good energy saving effect.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-stage drying system, characterized in that: It comprises a return air duct (101), an air supply air duct (102), a first drying area (103), a second drying area (104), a first compressor (105), a first heat exchanger (106), a second heat exchanger (107), a third heat exchanger (108), a first throttling mechanism (109), a first fan (110) and a second fan (111); The temperature in the first drying area (103) is higher than the temperature in the second drying area (104), and the return air duct (101) and the supply air duct (102) are connected; The exhaust port of the first compressor (105) is connected to the refrigerant inlet of the first heat exchanger (106), the refrigerant outlet of the first heat exchanger (106) is connected to the inlet of the first throttling mechanism (109), the outlet of the first throttling mechanism (109) is connected to the refrigerant inlet of the second heat exchanger (107), and the refrigerant outlet of the second heat exchanger (107) is connected to the suction port of the first compressor (105); The first heat exchanger (106) is installed in the air supply duct (102) or the air return duct (101), the second heat exchanger (107) is installed in the air return duct (101), and the first fan (110) is used to make the first air pass through the second heat exchanger (107) and the first heat exchanger (106) in sequence and send the first air into the first drying area (103); The second fan (111) is used to allow the first air in the first drying area (103) and the second air in the second drying area (104) to exchange heat with each other without contact through the third heat exchanger (108); the third heat exchanger (108) is connected to the return air duct (101) through an air duct so as to return the first air after heat exchange with the second air to the return air duct (101).

2. The multi-stage drying system according to claim 1, characterized in that: The multi-stage drying system (100) further comprises a first water receiving pan (112) and a first drain pipe (113), wherein the first water receiving pan (112) is arranged below the second heat exchanger (107), and the first drain pipe (113) is connected to the first water receiving pan (112) and is used to discharge water in the first water receiving pan (112) to outside the air duct and the drying area.

3. The multi-stage drying system according to claim 1, characterized in that: The multi-stage drying system (100) further comprises a second drain pipe (115), wherein the second drain pipe (115) is connected to the water circuit of the third heat exchanger (108) and is used to discharge condensed water generated by the third heat exchanger (108).

4. The multi-stage drying system according to claim 1, characterized in that: The multi-stage drying system (100) further includes a third fan (116), the third heat exchanger (108) is connected to the return air duct (101) via an air duct, and the third fan (116) is arranged in the air duct to send the first air back to the return air duct (101).

5. The multi-stage drying system according to claim 1, characterized in that: The first drying area (103) is connected to the return air duct (101) through an air duct, and an air valve is provided on the air duct between the first drying area (103) and the return air duct (101), and the air valve is used to open or close the air duct and to control the air volume of the first air entering the return air duct (101) from the first drying area (103).

6. The multi-stage drying system according to claim 1, characterized in that: The multi-stage drying system (100) further includes a fourth heat exchanger (117) and a fourth fan (118), both of which are located outside the drying area. The fourth heat exchanger (117) is used to exchange heat with the second air in the second drying area (104), and the fourth fan (118) is used to allow air to flow through the fourth heat exchanger (117).

7. The multi-stage drying system according to claim 1, characterized in that: The multi-stage drying system (100) also includes a fifth heat exchanger (119), a sixth heat exchanger (120), a fifth fan (121), a second throttling mechanism (122) and a second compressor (123); the fifth heat exchanger (119) is used for exchanging heat with the second air in the second drying area (104); the fifth fan (121) is used for allowing air to flow through the fifth heat exchanger (119); the fifth heat exchanger (119) is connected to the second throttling mechanism (122); the second throttling mechanism (122) is connected to the sixth heat exchanger (120); and the compressor is connected to the fifth heat exchanger (119) and the sixth heat exchanger (120), respectively.

8. The multi-stage drying system according to claim 1, characterized in that: The second drying area (104) is provided with air inlets and outlets for exchanging air with the outside air, and the air inlets and outlets are used to exchange the air in the second drying area (104) with the outside air.

9. The multi-stage drying system according to any one of claims 1 to 8, characterized in that: The multi-stage drying system (100) further includes a third drying area (124). The multi-stage drying system (100) further includes a seventh heat exchanger (125) and a sixth fan (126). The seventh heat exchanger (125) is used to exchange heat between the air in the third drying area (124) and the second air in the second drying area (104). The sixth fan (126) is used to allow air to flow through the seventh heat exchanger (125).

10. The multi-stage drying system according to claim 9, characterized in that: The multi-stage drying system (100) also includes an eighth heat exchanger (127), which is connected to the third heat exchanger (108) and is used to allow the first air to exchange heat with the air in the third drying area (124) after exchanging heat with the second air, and to allow the first air to return to the return air duct (101).

11. The multi-stage drying system according to any one of claims 1 to 8, characterized in that: The multi-stage drying system (100) further comprises 1 to N multi-stage drying areas, and the temperature of the i+1 multi-stage drying area is lower than the temperature of the i multi-stage drying area, wherein i is a positive integer and the value of i ranges from 1 to N-1; The multi-stage drying system (100) further comprises first to N multi-stage heat exchange components, each of which is capable of preventing two gases flowing through from contacting each other and allowing the two gases to exchange heat; When N=1, the first to N multi-stage heat exchange components are first multi-stage heat exchange components, and the first multi-stage heat exchange components are respectively connected to the second drying area (104) and the first multi-stage drying area through air ducts, so as to enable the gas in the second drying area (104) to exchange heat with the gas in the first multi-stage drying area without contact; When N≥2, the j-th multi-stage heat exchange component is connected to the j-th multi-stage drying area and the j-1-th multi-stage drying area through air ducts, respectively, so as to enable the gas in the j-th multi-stage drying area to exchange heat with the gas in the j-1-th multi-stage drying area without contact, wherein j is a positive integer and the value of j ranges from 2 to N.

12. The multi-stage drying system according to any one of claims 1 to 8, characterized in that: The multi-stage drying system (100) further comprises a transmission mechanism and a partitioning device, wherein the transmission mechanism is in driving connection with the partitioning device and is used to drive the partitioning device to move in the drying room so as to partition the drying room into at least two drying areas, wherein the at least two drying areas comprise the first drying area (103) and the second drying area (104).

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