A slow-speed static drying device with a drying collapse clearance compensation module

Abstract

The present invention relates to a slow-speed static drying device with a drying collapse gap compensation module, comprising a drying bin, wherein a plurality of orifice plates are used as partitions to construct a plurality of vertical grain drying cavities, a plurality of vertical first air ducts and a plurality of vertical second air ducts, wherein the first air ducts and the second air ducts are separated and connected by the drying cavity; during drying operation, a gap compensation module is provided on the top of the grain in the grain drying cavity, and the gap compensation module can move up and down along the inner wall of the grain drying cavity; the drying airflow enters the drying cavity through the first air duct, evaporates the moisture in the grain to become a warm and humid airflow, and is discharged through another second air duct; or, the drying airflow enters the drying cavity through the second air duct, evaporates the moisture in the grain to become a warm and humid airflow, and is discharged through another first air duct; the gap compensation module automatically compensates for the collapse gap space generated during the grain drying process by relying on its own weight.

Description

Technical Field

[0001] The invention relates to the technical field of grain drying, and in particular to a slow-speed static drying device with a drying collapse clearance compensation module. Background Art

[0002] Cereals are typical granular materials. In a drying device for granular wet materials, drying is achieved through heat and mass transfer between dry air and the granular wet materials.

[0003] A heat recovery grain heat pump drying system combines a grain dryer with a heat pump unit. The grain dryer is where dry air exchanges heat and moisture with moist grain, extracting moisture from the grain. The heat pump unit acts as a heat source, while the evaporator, acting as a cooling system, continuously extracts heat from the dryer's exhaust air and / or ambient air, producing dry air through the condenser.

[0004] At present, the grain dryers widely used in our country are all circulating grain dryers, such as Figure 1 As shown in the figure, the grain at the bottom of the grain dryer is transported to the top by the elevator, and then slowly moves from the top to the bottom, repeating this cycle until the grain is dried. In each cycle, the grain passes through the "drying section" at the waist of the dryer, where the moisture on the grain surface is heated and evaporated by the high-temperature dry air. The grain then enters the "slow drying section" where the moisture diffuses from the interior of the grain to the surface, preparing for the next hot air drying stage.

[0005] The drying section of the grain dryer is a space consisting of a vertical downward grain trough enclosed by two metal mesh panels and a horizontal inlet and outlet duct for hot air. It is the place where the heat of the dry air and the moisture of the wet grains undergo "heat and moisture exchange";

[0006] In the grain drying device, the heat and moisture exchange process between dry air and moist grain is an "isenthalpic" process expressed on the air enthalpy-humidity diagram, such as Figure 2 a→b in .

[0007] from Figure 2 An important conclusion can be drawn that the energy characteristic of the drying process of wet materials such as grains is that the heat (enthalpy value) of the drying air at the outlet of the drying process is equal to the heat (enthalpy value) at the inlet of the drying process!

[0008] This is because, during the "isenthalpic" heat and moisture exchange process of drying the wet material in the drying unit, the drying air cools down and releases sensible heat, which drives the moisture in the wet material to absorb heat and vaporize. During this process, the drying air and the drying unit do not perform any external work, and the total heat content of the drying unit's thermal system does not decrease. Instead, some of the heat is converted from the dry air's "sensible heat" to the "latent heat" of water vapor. Therefore, recovering heat from the outlet air of a drying unit, which directly performs heat and mass transfer and heat and moisture exchange, has far greater technical and commercial significance than other thermal systems (such as internal combustion engines and boiler turbines).

[0009] As a "heat carrier", the heat recovery heat pump can move the low-grade heat from the air outlet of the drying device for wet materials such as grains back to high-grade heat and send it back to the air inlet of the drying device, allowing the heat to circulate between the evaporation of moisture in the wet material and the heat recovery of water vapor condensation, greatly improving the heat utilization rate and significantly reducing the drying cost.

[0010] However, the main problem faced in the promotion and application of heat recovery technology for the exhaust air of drying equipment for wet materials such as grains is the pollution of the heat pump heat absorption device (evaporator) by dust in the exhaust air.

[0011] As mentioned above, during the grain drying process in the circulating dryer, the grain is in continuous motion and is continuously transported to the top of the dryer by the elevator, and then thrown 360° by the grain throwing plate; then it enters the slow drying section and slowly moves downward, and then the grain enters the drying section again; finally, it flows into the bottom of the dryer and enters the elevator suction port to start a new cycle. The problem stems from the drying process: the grain is in continuous motion, and the soil attached to the surface of the grain particles dries and peels off due to loss of moisture, and the grain hair and husk are powdered due to mutual friction between the grain particles; the dried and peeled soil and powdered grain hair and husk on the surface of the grain particles are entrained by the drying airflow in the drying section of the circulating dryer and become dust in the air outlet of the drying device, with a concentration of 0.5g / m 3 When the dust-laden air from the drying device is introduced into the evaporator of the heat recovery type heat pump unit for heat recovery, a large amount of condensed water is generated on the evaporator because the air is cooled and dehumidified. The dust adheres to the evaporator fins along with the condensed water, causing serious pollution, increasing the evaporator's dirt thermal resistance, and blocking the air duct between the evaporator fins. In addition, on the culture medium composed of moist soil, dust, and grain hair and husks between the evaporator fins, microorganisms and bacteria multiply rapidly, leading to regional mold, causing the evaporator to degrade in function or even become scrapped. Summary of the Invention

[0012] To solve the above problems, the present invention provides a slow-speed static drying device with a drying collapse clearance compensation module, comprising a drying chamber, wherein a plurality of perforated plates are used as partitions to construct a plurality of vertical grain drying chambers, a plurality of vertical first air ducts, and a plurality of vertical second air ducts, wherein the first air ducts and the second air ducts are separated and connected by the drying chamber;

[0013] During the drying operation, a gap compensation module is set on the top of the grain in the grain drying cavity, and the gap compensation module can move up and down along the inner wall of the grain drying cavity; the drying airflow enters the drying cavity through the first air duct, evaporates the moisture in the grain to become warm and moist airflow, and is discharged through the second air duct; or, the drying airflow enters the drying cavity through the second air duct, evaporates the moisture in the grain to become warm and moist airflow, and is discharged through the first air duct; the gap compensation module relies on its own weight to automatically compensate for the collapsed gap space generated during the grain drying process.

[0014] Preferably, when the clearance compensation module slides down along with the collapsed clearance space generated during the grain drying process, it is dynamically sealed with the inner wall of the grain drying cavity corresponding to the collapsed clearance space.

[0015] Preferably, a first air duct and a second air duct are respectively provided on the outside of the drying chamber, and a plurality of first air outlets are provided on the first air duct, and the plurality of first air outlets are respectively connected to the plurality of first air ducts; a plurality of second air outlets are provided on the second air duct, and the plurality of second air outlets are respectively connected to the plurality of second air ducts.

[0016] Preferably, a heat recovery heat pump is used as the drying heat source, the air outlet of the condenser group of the heat recovery heat pump is connected to several first air ducts through the first air duct, and the air inlet of the evaporator group is connected to several second air ducts through the second air duct.

[0017] Preferably, the air outlet of the condenser group and the air inlet of the evaporator group are switchably connected to the first air duct and the second air duct respectively through an air door conversion device.

[0018] Compared with the prior art, the present invention has the following technical effects:

[0019] The present invention provides a slow-speed static drying device with a drying collapse gap compensation module, which fully utilizes the excellent thermophysical properties of grain grains and integrates a series of technologies including slow-speed drying, static drying, and automatic gap compensation. The device has the following distinct technical features: low heat leakage from the drying bin to the environment, efficient evaporation and dehydration of grain grains, clean return air from the drying bin with a high enthalpy value, and high dry-basis grain quality and yield rate.

[0020] ① Automatic compensation of the gap in the collapsed space

[0021] During the grain drying process, the grain loses water and its volume collapses, resulting in a collapsed "gap" at the top of the grain in the vertical grain drying chamber, which causes the drying airflow to short-circuit, resulting in a reduction in the drying air flow in the gaps where the grain particles accumulate, thereby reducing the drying speed and efficiency.

[0022] The clearance compensation module provided in the present invention can move downward along with the collapsed clearance space generated during the grain drying process and fill the collapsed clearance space. The clearance compensation module automatically compensates for the collapsed clearance space generated during the grain drying process by its own weight to prevent the drying airflow from short-circuiting.

[0023] ② Improved space utilization and heat recovery value

[0024] The present invention adopts full-bin multi-row slow-speed static drying, eliminating the slow-down zone and grain circulation of traditional circulating grain dryers, improving drying space utilization and grain drying efficiency, and achieving efficient evaporation and dehydration of wet grains. Compared with traditional circulating dryers, the present invention reduces the heat leakage intensity of the drying bin to the environment and increases the enthalpy value of the return air from the drying bin, greatly improving the technical and commercial value of return air heat recovery.

[0025] ③The cleanliness of the return air in the drying chamber is improved

[0026] The present invention adopts micro-speed static drying, and the drying airflow passes through the grain layer at a micro-speed and then is discharged. Compared with the traditional circulating dryer, it overcomes the problem that the grain hair and husk are powdered due to the friction between the relative movement of the grain particles, and the soil attached to the surface of the grain particles is dried and peeled off due to loss of moisture and then re-enters the drying airflow to become dust. In addition, the cross-sectional area of the airflow passing through the grain layer is large, and the drying airflow speed is less than 0.3m / s. Micro-speed drying is implemented, and the micro-speed airflow cannot carry dust away from the grain layer, resulting in a good gas-solid separation effect and improved cleanliness of the drying return air, which is beneficial to preventing dust pollution, facilitating the safe and reliable operation of heat absorption devices such as heat pump evaporators, and facilitating heat recovery of heat pumps.

[0027] ④Good quality of grain on dry basis

[0028] The grains are dried in a static state, and the drying airflow flows through the air gaps between the grain particles in a naturally stacked state, penetrates at a slow speed, and dries continuously at a low temperature. The breakage rate and crack rate of the grain particles are greatly reduced, and the drying unevenness is greatly reduced. The dry basis grain has good quality and a high yield.

[0029] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive efforts. In the drawings:

[0031] Figure 1 The schematic diagram of the circulating dryer provided by the prior art;

[0032] Figure 2 It is the drying airflow state diagram during the drying process on the wet air enthalpy-psychrometric diagram;

[0033] Figure 3 A front view of a slow-speed static drying device with a drying collapse clearance compensation module provided in a preferred embodiment of the present invention;

[0034] Figure 4 A top view of a slow-speed static drying device with a drying collapse clearance compensation module provided in a preferred embodiment of the present invention;

[0035] Figure 5 A front view of the drying airflow of a slow-speed static drying device with a drying collapse clearance compensation module provided in a preferred embodiment of the present invention;

[0036] Figure 6 A top view of the drying airflow of a slow-speed static drying device with a drying collapse clearance compensation module provided in a preferred embodiment of the present invention;

[0037] Figure 7 A schematic structural diagram of a heat recovery heat pump provided in a preferred embodiment of the present invention;

[0038] Figure 8 An airflow diagram of the drying operation of the drying device provided by a heat recovery type heat pump as a heat source according to a preferred embodiment of the present invention;

[0039] Figure 9 A schematic diagram of the drying operation airflow of the drying device when the damper conversion device is switched to the forward direction according to the preferred embodiment of the present invention;

[0040] Figure 10 A schematic diagram of the drying operation airflow of the drying device when the damper conversion device is switched to the reverse direction according to the preferred embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will be combined Figures 3 to 10A detailed description is given of a slow static drying device with a drying collapse gap compensation module provided by the present invention. This embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation method and specific operation process are given. However, the protection scope of the present invention is not limited to the following embodiments. Those skilled in the art can modify and polish it without changing the spirit and content of the present invention.

[0042] The present invention provides a slow-speed static drying device with a drying collapse gap compensation module. The device is based on the research and analysis of the thermophysical properties of granular grains such as corn, wheat, rice, and soybeans. As shown in Table 1, granular grains have the following thermophysical properties:

[0043] Table 1 Comparison table of bulk density and true density of grains

[0044] Cereal Type <![CDATA[Bulk density kg / m 3 > <![CDATA[True density kg / m 3 > Rice (hulled) 750 1108 Wheat (hulled) 770 1125 corn (hulled) 720 1195-1267

[0045] ①High mechanical strength

[0046] Mature grains have dense internal structures and hard shells, and possess full and solid mechanical characteristics. They can be stacked to a height of 30m or even higher in a cylindrical granary.

[0047] ②The air gap is uniform and dense

[0048] Grain bulk density is 750kg / m 3 The density of the grain is only about 2 / 3 of the grain body density (true density). Except for point contacts between the grains, the grains are surrounded by uniform and dense air gaps. These uniform and dense air gaps are everywhere and together with the grains constitute the grain pile itself.

[0049] ③Has uniform orifice plate throttling characteristics

[0050] When hot air penetrates and dries the grain pile, the air gaps between the fine and uniform particles act as capillaries for the drying airflow to pass through at a low speed and evenly, and also serve as natural and excellent throttling orifices for the drying airflow.

[0051] ④Excellent drying properties

[0052] The specific surface area of grain particles is very large, 1m 3 The total surface area of the grains can reach several thousand or even tens of thousands of square meters, which is very conducive to surface heating of grain particles, water evaporation, and airflow drying.

[0053] Based on the above-mentioned thermophysical properties of granular grains, the present invention provides a slow-speed static drying device with a drying collapse gap compensation module, including a drying bin 1, wherein a plurality of orifice plates 18 covered with small holes and having good air flow permeability are used as partitions in the drying bin 1 to construct a vertical grain drying cavity 13 and a vertical air duct, and a plurality of the drying cavities 13 and the plurality of air ducts are arranged alternately. In the present invention, the plurality of air ducts include a plurality of first air ducts 14 and a plurality of second air ducts 15, the number of the first air ducts 14 and the number of the second air ducts 15 being the same, and the two being separated and connected by the drying cavity 13, that is, the plurality of first air ducts 14 and the plurality of second air ducts 15 are arranged alternately by the plurality of the drying cavities 13. In the present invention, among the first air ducts 14 and the second air ducts 15, if one of the air ducts is used as a supply air duct for high-temperature dry air, the other air duct is used as a return air duct for warm and humid air. The present invention does not make a specific specification for this, and it can be set according to actual use requirements.

[0054] In the present invention, a plurality of vertical grain drying chambers 13 are arranged in multiple rows along the horizontal direction and separated by vertical air layers (air ducts) to form a full-bin multi-row slow-speed static drying device for loading granular wet grains. The air separation layers on both sides of the vertical grain drying chamber 13 are defined as high-temperature dry air ducts (high-temperature dry air ducts are also called air supply ducts, which are used to pass high-temperature dry air outside the drying chamber 1. High-temperature dry air is also called drying airflow) and warm and humid air ducts (high-temperature dry air enters the drying chamber 13, evaporates the moisture of the grain in the drying chamber 13 and becomes warm and humid air. The warm and humid air is then discharged to the outside of the drying chamber 1 through the warm and humid air ducts. The warm and humid air ducts are also called return air ducts). They are separated and connected by the grain drying chamber 13. As to which duct is the high-temperature dry air duct and which duct is the warm and humid air duct, the present invention does not make specific restrictions on this. It can be set according to the airflow direction of the high-temperature dry air sent into the drying chamber 1.

[0055] During the drying operation, the grain drying cavity 13 is pre-loaded with wet grains, and high-temperature dry air is sent into each high-temperature dry air duct from outside the warehouse. The high-temperature dry air then enters each drying cavity 13 (in the grain drying cavity 13, there are no other air flow channels except the accumulation gaps between the densely distributed grain particles), evaporates the moisture in the grain in the drying cavity 13 into warm and humid air flow, and then is discharged out of the warehouse through the warm and humid air duct.

[0056] During the drying process, the grains collapse in volume due to the loss of moisture, and a "drying collapse gap" appears on the top of the grains, causing the drying airflow (high-temperature dry air) to not enter the stacking gaps between the grain particles through the air supply duct, but to directly enter the warm and humid air duct through the collapsed gap, resulting in an "airflow short circuit". The drying intensity and efficiency are seriously reduced. This is a key problem of the full-bin multi-row slow-speed static drying device composed of a vertical grain drying cavity. Therefore, the present invention provides a gap compensation module 12 on the top of the grain in each of the grain drying cavities 13, and the gap compensation module 12 can move up and down along the inner wall of the grain drying cavity 13; the drying airflow enters the drying cavities 13 respectively through the supply ducts, evaporates the moisture in the grains into warm and humid airflow, and is discharged through the return air ducts; the gap compensation module 12 automatically compensates for the collapsed gap space generated during the grain drying process by its own weight.

[0057] The present invention does not impose any restrictions on the specific structure of the clearance compensation module 12, as long as it can move downward along with the collapsed clearance space generated during the grain drying process and fill the collapsed clearance space so that the collapsed clearance space is blocked from the air flow channels between the high-temperature dry air duct and the warm and humid air duct respectively.

[0058] The present invention does not impose any specific restrictions on the number of grain drying cavities 13 and the number of air ducts, and several specific embodiments are listed below for detailed description.

[0059] Example 1

[0060] Please refer to Figures 3 to 6 This embodiment provides a slow-speed static drying device with a drying collapse gap compensation module, including a drying bin 1, in which a plurality of orifice plates 18 covered with small holes and having good air flow permeability are arranged at intervals. The orifice plates 18 and the bin wall of the drying bin 1 form a plurality of vertical air ducts and a plurality of vertical grain drying cavities 13, and the plurality of air ducts are separated by the plurality of grain drying cavities 13.

[0061] In this embodiment, the height of the clearance compensation module 12 is greater than the height of the collapsed clearance space generated in the grain drying cavity 13 during the drying process. The purpose is that when the clearance compensation module 12 slides down along with the collapsed clearance space generated during the grain drying process, it can always block the holes corresponding to the collapsed clearance space, and will not cause the holes corresponding to the collapsed clearance space to directly communicate with the high-temperature dry air duct and the warm and humid air duct without passing through the grain.

[0062] In order to further enhance the sealing performance of the holes corresponding to the collapsed gap space sealed by the clearance compensation module 12, during the drying process, in order to ensure that the clearance compensation module 12 can always seal the holes corresponding to the collapsed gap space, the clearance compensation module 12 always dynamically seals with the inner wall of the grain drying cavity 13 corresponding to the collapsed gap space when it slides down along with the collapsed gap space generated during the grain drying process.

[0063] In this embodiment, a plurality of grain inlets 11 are provided at the top of the drying bin 1, each of which is connected to a plurality of grain drying chambers 13. Before the drying operation, the wet grain is first loaded into the grain drying chamber 13 through the grain inlets 11, and then the clearance compensation module 12 is placed on top of the grain through the grain inlets 11.

[0064] In this embodiment, the plurality of air ducts include a plurality of first air ducts 14 and a plurality of second air ducts 15. The number of the first air ducts 14 and the second air ducts 15 is the same, and the two are separated and connected by the drying cavity 13. The two sides of each of the grain drying cavity 13 are respectively connected to a first air duct 14 and a second air duct 15 through its perforated plate 18.

[0065] The air ducts used for supplying air can supply air individually or in a unified manner; similarly, the air ducts used for exhausting air can exhaust air individually or in a unified manner, and the present invention does not impose any specific restrictions on this.

[0066] As an embodiment, a first air duct 16 and a second air duct 17 are respectively provided on the outside of the drying chamber 1. The first air duct 16 is provided with a plurality of first air outlets, which are respectively connected to a plurality of first air ducts 14; the second air duct 17 is provided with a plurality of second air outlets, which are respectively connected to a plurality of second air ducts 15. If the first air duct 14 is a supply air duct and the second air duct 15 is a return air duct, the first air duct 16 is the supply air duct and the second air duct 17 is the return air duct; similarly, if the first air duct 14 is a return air duct and the second air duct 15 is a supply air duct, the first air duct 16 is the return air duct and the second branch air duct 17 is the supply air duct.

[0067] Taking the first air duct 14 as the return air duct and the second air duct 15 as the supply air duct as an example, the first air duct 16 is the return air duct, and the return air duct is provided with a plurality of return air ports, and the plurality of return air ports are respectively connected to the plurality of return air ducts; the second air duct 17 is the supply air duct, and the supply air duct is provided with a plurality of supply air ports, and the plurality of supply air ports are respectively connected to the plurality of supply air ducts. These air ducts separated by the grain drying cavity 13 are numbered 1, 2, 3, 4, 5, 6... from left to right. The odd-numbered first air ducts 14 such as 1, 3, 5... are return air ducts, which are all connected to the return air ducts, and the even-numbered second air ducts 15 such as 2, 4, 6... are supply air ducts, which are all connected to the supply air ducts. Adjacent odd-numbered return air ducts and even-numbered supply air ducts are separated by the grain drying cavity 13; vice versa. During the drying operation, there are no other air flow channels except the accumulation gaps between the densely distributed grain particles in the grain drying cavity 13 .

[0068] During the drying operation, the drying airflow from the heat source is decomposed into multiple air supply ducts with even numbers such as 2, 4, 6..., the drying airflow is decelerated and pressurized, and diffuses slowly into the gaps between the grain particles in the grain drying chamber 13, passes through the accumulated gaps between the grain particles, evaporates the grain moisture to become warm and humid airflow, and then enters the adjacent return air ducts with odd numbers such as 1, 3, 5..., etc. After the multiple warm and humid airflows are gathered, they are finally discharged from the drying device; the collapsed gap space caused by water loss during the grain drying process is automatically closed by the gap compensation module 12.

[0069] Several grain discharge ports are set on the lower end surface of the drying bin 1, and the several grain discharge ports are respectively connected to the lower ends of several grain drying cavities 13. Before the grain drying is completed, the grain discharge ports are closed. When the grain drying is completed, the grain discharge ports are opened, and the dried grains are discharged onto the grain unloading conveyor belt 2 below the drying bin 1, and the dried grains are transported away by the grain unloading conveyor belt 2.

[0070] Example 2

[0071] This embodiment is a further improvement on the basis of embodiment 1. Figure 7 and Figure 8 This embodiment adopts a heat recovery heat pump 3 as a drying heat source, which has the excellent technical quality of significantly saving energy and reducing emissions.

[0072] In this embodiment, the heat recovery heat pump 3 includes a compressor unit 32, a condenser unit 33, a throttling device, an evaporator unit 34, and a centrifugal fan 31. The compressor unit 32, condenser unit 33, throttling device, and evaporator unit 34 are sequentially connected to form a refrigerant circulation system. The air inlet of the evaporator unit 34 is connected to a plurality of first air ducts 14 (return air ducts) via a first air duct 16 (return air duct), and the air outlet of the condenser unit 33 is connected to a plurality of second air ducts 15 (supply air ducts) via a second air duct 17 (supply air duct). Outside air enters the condenser unit 33 through the air inlet, is heated to become high-temperature dry air, and is then fed into the supply air duct. The warm, moist air discharged through the return air duct passes through the evaporator unit 34 through the air inlet, and is finally discharged through the fan.

[0073] This embodiment adopts micro-speed static drying, and the drying airflow passes through the grain layer in the vertical grain drying chamber 13 at a micro-speed and then is discharged. Compared with the traditional circulating dryer, it overcomes the problem that the grain hair and husk are powdered due to the relative movement and mutual friction between the grain particles, and the soil attached to the surface of the grain particles is dried and peeled off due to loss of moisture and then re-enters the drying airflow to become dust. In addition, the cross-sectional area of the airflow passing through the grain layer is large, and the drying airflow speed is less than 0.3m / s. Micro-speed drying is implemented, and the micro-speed airflow cannot carry dust out of the grain layer. The gas-solid separation effect is good, and the cleanliness of the drying return air is improved, which is beneficial to preventing dust pollution, and is beneficial to the safe and reliable operation of heat absorption devices such as heat pump evaporators, and is beneficial to heat pump heat recovery.

[0074] This embodiment uses the technology of step-by-step recovery of waste heat from the drying device’s outlet air and step-by-step heating of dry air to carry out step-by-step recovery of waste heat from the drying bin’s outlet air, which is mainly the latent heat of water vapor. This realizes the heat cycle of “heat pump condenser heats air input into the drying bin – dry air heats grains and absorbs moisture from the grains to evaporate and generate water vapor to become warm and humid outlet air – heat pump evaporator recovers the latent heat of water vapor from the drying bin’s outlet air”, which greatly improves the evaporation pressure of the heat pump system, thereby greatly improving the heating power and heating energy efficiency of the heat pump unit, effectively controlling the compressor exhaust temperature, improving the safety and reliability of the heat pump system, and achieving a higher level of energy conservation and emission reduction.

[0075] Example 3

[0076] This embodiment is further improved on the basis of embodiment 2. Figure 9 and Figure 10 In this embodiment, the air outlet of the condenser group 33 and the air inlet of the evaporator group 34 are respectively switchably connected to the first air duct 16 and the second air duct 17 through the damper conversion device 4: please refer to Figure 9When the damper conversion device 4 is switched to the forward direction, the air inlet of the evaporator group 34 is connected to the odd-numbered first air ducts 14 such as 1, 3, 5, etc. through the first air duct 16. These odd-numbered first air ducts 14 are return air ducts. The air outlet of the condenser group 33 is connected to the even-numbered second air ducts 15 such as 2, 4, 6, etc. through the second air duct 17. These even-numbered second air ducts 15 are supply air ducts. Please refer to Figure 10 When the damper conversion device 4 is switched to the reverse direction, the air inlet of the evaporator group 34 is connected to the second air ducts 15 with even numbers such as 2, 4, 6... through the second air duct 17. These even-numbered second air ducts 15 are return air ducts. The air outlet of the condenser group 33 is connected to the first air ducts 14 with odd numbers such as 1, 3, 5... through the first air duct 16. These odd-numbered first air ducts 14 are supply air ducts.

[0077] This embodiment adopts the forward and reverse switching technology of drying airflow to realize the conversion of the first air duct 14 and the second air duct 15, and implements forward and reverse drying of the grain layer in the vertical grain drying cavity, which has the technical effect of improving drying efficiency and drying uniformity.

Claims

1. A slow-speed static drying device with a drying collapse clearance compensation module, characterized in that: The drying chamber comprises a plurality of vertical grain drying chambers, a plurality of vertical first air ducts and a plurality of vertical second air ducts formed by using a plurality of perforated plates as partitions in the drying chamber, wherein the first air ducts and the second air ducts are separated and connected by the drying chamber; Use heat recovery heat pump as drying heat source; During the drying operation, a clearance compensation module is provided on the top of the grain in the grain drying chamber, and the clearance compensation module can move up and down along the inner wall of the grain drying chamber; the drying airflow generated by the heat recovery heat pump enters the drying chamber through the first air duct, evaporates the moisture in the grain to become warm and moist airflow, and is discharged through the second air duct; or the drying airflow generated by the heat recovery heat pump enters the drying chamber through the second air duct, evaporates the moisture in the grain to become warm and moist airflow, and is discharged through the first air duct; the clearance compensation module automatically compensates for the collapsed clearance space generated during the grain drying process by its own weight; When the clearance compensation module slides down along with the collapsed clearance space generated during the grain drying process, it is dynamically sealed with the inner wall of the grain drying cavity corresponding to the collapsed clearance space.

2. A slow-speed static drying device with a drying collapse clearance compensation module according to claim 1, characterized in that: A first air duct and a second air duct are respectively arranged on the outside of the drying chamber, and a plurality of first air outlets are arranged on the first air duct, and the plurality of first air outlets are respectively connected to the plurality of first air ducts; a plurality of second air outlets are arranged on the second air duct, and the plurality of second air outlets are respectively connected to the plurality of second air ducts.

3. A slow-speed static drying device with a drying collapse clearance compensation module as claimed in claim 2, characterized in that: The air outlet of the condenser group of the heat recovery type heat pump is communicated with a plurality of first air ducts respectively through the first air duct, and the air inlet of the evaporator group is communicated with a plurality of second air ducts respectively through the second air duct.

4. A slow-speed static drying device with a drying collapse clearance compensation module as claimed in claim 3, characterized in that: The air outlet of the condenser group and the air inlet of the evaporator group are respectively switchably connected to the first air duct and the second air duct through an air door conversion device.

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