Bulk grain low-temperature bin capable of actively controlling temperature on six surfaces
By evenly distributing the refrigerant circulation system and temperature measurement cables on the inner wall and floor of the bulk grain low-temperature warehouse, and automatically adjusting the refrigerant flow, the six-sided active temperature control of the grain temperature is achieved, the "hot skin and cold core" phenomenon is solved, and the quality and safety of grain are ensured.
Patent Information
- Application Number
- CN202422151719.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-02
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-09-02
AI Technical Summary
Existing bulk grain low-temperature warehouses are prone to "hot skin and cold core" in summer, resulting in uncontrolled grain temperature and prone to pest and deterioration in grain quality.
A bulk grain low-temperature silo with active temperature control on six sides was designed, using a grain surface temperature maintenance device, a grain stack temperature maintenance device and a control system. The refrigerant circulation system and temperature measurement cable were uniformly distributed on the inner wall and floor of the silo, and the refrigerant flow was automatically adjusted to achieve temperature control of the inner wall and floor of the silo.
It effectively solves the phenomenon of "hot skin and cold core", ensures that the temperature of the grain during storage is controlled within the set value, avoids pests and grain quality deterioration, and reduces losses.
Smart Images
Figure CN223025000U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of grain storage, and particularly relates to a low-temperature bin for bulk grain with six-sided active temperature control. Background Art
[0002] In China, a granary with a bin temperature maintained below 15°C is called a low-temperature bin. The low-temperature bin can basically stabilize the quality of grains and reduce the occurrence of pests.
[0003] In hot summer regions, the main method for the existing low-temperature bin for bulk grain to maintain low temperature is: mechanically ventilating the grain pile in winter to reduce the grain pile temperature below 15°C, and using low-temperature air conditioners on the grain surface to maintain the bin temperature in summer. This method can maintain the average grain temperature at about 15°C in the fifth and seventh ecological grain storage areas. However, due to the heat transfer law of the bulk grain bin, the phenomenon of "hot skin and cold core" appears in the grain pile, and the grain temperature near the outer wall will be much higher than 15°C. Nearly 10%-25% of the grain temperature is in an uncontrolled state. The pests in the grains in the uncontrolled state need to be fumigated or treated with nitrogen gas conditioning to be effectively controlled. At the same time, the quality of the grains in the uncontrolled state also gradually deteriorates.
[0004] In recent years, with the improvement of national environmental protection requirements, the pest control technology using chemical fumigation is increasingly restricted in use. At the same time, fumigation will affect the health of operators and the residues of fumigants in grains. Summary of the Utility Model
[0005] The utility model provides a low-temperature bin for bulk grain with six-sided active temperature control to solve the problem of the phenomenon of "hot skin and cold core" in the grain pile and ensure that the grain quality can be basically stable without using fumigants during grain storage.
[0006] To solve the above problems, the low-temperature bin for bulk grain with six-sided active temperature control provided by the utility model adopts the following technical solutions:
[0007] A low-temperature bin for bulk grain with six-sided active temperature control includes a grain surface temperature maintenance device, a grain pile temperature maintenance device, and a control system. The grain pile temperature maintenance device includes a refrigerant circulation system and a temperature measurement cable. The refrigerant circulation system includes a cooling coil, a refrigerant unit, and a flow distribution device. The flow distribution device and the temperature measurement cable are electrically connected to the control system. The cooling coil and the temperature measurement cable are evenly distributed on the inner wall of the bin and the floor directly in contact with the grain pile. The refrigerant unit provides refrigerant for the cooling coil, and the refrigerant controls the flow of refrigerant into / out of the cooling coil through the flow distribution device;
[0008] When the control system monitors that the temperature inside the bin is higher than the set temperature value, the grain surface temperature maintaining device and the grain pile temperature maintaining device are started. The grain surface temperature maintaining device is used to maintain the temperature of the upper part of the grain surface within the set temperature value; the grain pile temperature maintaining device automatically adjusts the refrigerant flow rate of the flow distribution device according to the temperature real-time feedback by the temperature measuring cable, so that the temperatures of the bin inner wall and the floor are controlled within the set temperature value, so as to realize the six-sided active temperature control function of the low-temperature bin.
[0009] As a preferred technical solution of the present invention, the grain surface temperature maintaining device includes a temperature sensor, a circulation fan and a low-temperature unit arranged at the upper part of the low-temperature bin.
[0010] As a preferred technical solution of the present invention, a dew point temperature sensor is arranged inside the low-temperature unit to monitor the dew point temperature t1 of the air on the grain surface, and the dew point temperature sensor is electrically connected to the control system.
[0011] As a preferred technical solution of the present invention, the refrigerant temperature tw provided by the refrigerant unit satisfies tw≥t1 + 2°C. This setting prevents condensation inside the bin caused by the refrigerant temperature tw being lower than the dew point temperature t1.
[0012] As a preferred technical solution of the present invention, the refrigerant is cooling water, the flow distribution device is a manifold, and the refrigerant unit is an air-conditioning chilled water unit.
[0013] As a preferred technical solution of the present invention, the low-temperature bin includes a bin wall and a floor. The bin wall includes a decorative layer, an anti-cracking mortar layer, a mesh cloth layer, a thermal insulation layer, a leveling layer, a wall body and a plastering layer from the inside to the outside; the cooling coil and the temperature measuring cable are laid in the anti-cracking mortar layer.
[0014] As a preferred technical solution of the present invention, the floor includes a C25 concrete layer, a steel wire layer, a cement mortar layer, a thermal insulation layer, a waterproof layer, a leveling layer, a crushed stone cushion layer and a rammed earth layer from top to bottom; the cooling coil and the temperature measuring cable are laid in the cement mortar layer.
[0015] As a preferred technical solution of the present invention, the thermal insulation layer is an extruded polystyrene board, a polystyrene foam board or a polyurethane foam layer; the leveling layer is a cement mortar, a C15 concrete layer or a C20 concrete layer.
[0016] As a preferred technical solution of the present invention, the decorative layer is coated with a food coating.
[0017] As a preferred technical solution of the present invention, the waterproof layer is an ethylene propylene diene monomer (EPDM) polymer waterproof coiled material, a polyvinyl chloride (PVC) waterproof coiled material or a polyurethane waterproof coating layer.
[0018] The utility model realizes the low temperature of the whole bin of bulk grain through the grain surface temperature maintaining device and the grain pile temperature maintaining device, ensuring that the temperature of the whole bin of grain in the granary is controlled within the set temperature value, and the highest grain temperature does not exceed the set temperature value, ensuring that no fumigant is used during the grain storage period and maintaining the basic stability of the grain quality, reducing losses and achieving pest-free occurrence.
[0019] The beneficial effects are as follows:
[0020] In order to solve the phenomenon of "hot skin and cold core" in the grain pile of the existing low-temperature bin for bulk grain, the utility model evenly lays cooling coils and temperature measuring cables on the inner wall and floor of the granary. The temperature measuring cables are used to detect the temperature of the inner wall of the bin, and the cooling coils are passed through the refrigerant to take out the heat transmitted from outside the bin, maintaining the temperature of the grain in contact with the inner wall and floor of the grain pile below the set temperature value, so that the grain in contact with the inner wall and floor of the bin is cooled, ensuring the temperature control of the whole bin.
[0021] 2. In order to prevent condensation in the bin, the temperature tw of the refrigerant provided for the cooling coil is ≥ t1 + 2 °C, where t1 is the dew point temperature. Description of the drawings
[0022] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present utility model will become easy to understand. In the drawings, several embodiments of the present utility model are shown in an exemplary rather than restrictive manner, and the same or corresponding reference numerals represent the same or corresponding parts, where:
[0023] Figure 1 It is a schematic structural diagram of the refrigerant circulation system (including the installation and laying schematic diagram of the cooling coil on the bin wall and floor);
[0024] Figure 2 It is a schematic structural diagram of the laying of the cooling coil and the temperature measuring cable on the floor;
[0025] Figure 3 For Figure 2 The sectional view along the A-A direction;
[0026] Figure 4 For Figure 2 The sectional view along the B-B direction;
[0027] Figure 5 It is a schematic structural diagram of the bin wall and the floor.
[0028] Description of the reference numerals:
[0029] 1. Cooling coil; 2. Refrigerant unit; 3. Flow distribution device; 4. Temperature measurement cable; 5. Bin wall; 51. Finishing layer; 52. Anti-cracking mortar layer; 53. Mesh cloth layer; 54. Insulation layer; 55. Leveling layer; 56. Wall body; 57. Plastering layer; 6. Floor; 61. C25 concrete layer; 62. Steel wire layer; 63. Cement mortar layer; 65. Waterproof layer; 67. Crushed stone cushion layer; 68. Rammed plain soil layer. Specific implementation mode
[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of the present invention.
[0031] The number of any element in the drawings is for illustration rather than limitation, and any naming is only for distinction and does not have any limiting meaning.
[0032] The following refers to several representative implementation modes of the present invention to elaborate in detail the principles and spirits of the present invention.
[0033] As Figures 1-4 shown, a low-temperature bin for bulk grain with six-sided active temperature control includes a grain surface temperature maintenance device, a grain pile temperature maintenance device, and a control system. When the atmospheric temperature rises and the control system monitors that the temperature inside the bin is higher than the set temperature value, the grain surface temperature maintenance device and the grain pile temperature maintenance device are turned on, and the heat transferred into the bin due to the temperature difference outside the bin is immediately discharged outside the bin, keeping the temperature of the structure (including the inner wall of the bin and the floor 6) in direct contact with the grain pile at about the set temperature value. The heat generated by the grain with a temperature lower than the set temperature value is relatively low and can be basically ignored, ensuring that the grain temperature of the whole bin is maintained below the set temperature value. In this embodiment, the grain surface temperature maintenance device maintains the temperature of the upper part of the grain surface within the set temperature value; the grain pile temperature maintenance device maintains the temperature of the inner wall of the bin and the floor 6 within the set temperature value, realizing the six-sided active temperature control function of the low-temperature bin. In this example, the set temperature value is 15°C. Of course, in other embodiments, it can also be 10°C, 9°C, 5°C, or 0°C, etc.
[0034] The grain surface temperature maintaining device includes a plurality of temperature sensors, a circulation fan and a low-temperature unit arranged at the upper part of the low-temperature warehouse. There are at least four temperature sensors, which are respectively located at the four corners of the warehouse of the low-temperature warehouse. The control system starts and stops the circulation fan and the low-temperature unit according to the temperature values fed back by the temperature sensors. A dew point temperature sensor is arranged in the low-temperature unit to monitor the dew point temperature t1 of the air on the grain surface. The dew point temperature sensor is electrically connected to the control system. The circulation fan makes the temperature and humidity distribution of each area above the grain surface uniform by circulating air, preventing the grain from spoiling due to excessive local temperature. The grain surface temperature maintaining device is of the air-cooled type, used to control the grain surface temperature and air humidity, ensuring that the heat in the warehouse and the moisture in the air infiltrating into the warehouse are discharged outside the cabin in time, and maintaining the warehouse temperature and humidity within the set range (such as the air temperature on the grain surface is 15°C and the relative humidity is 65%). The low-temperature unit is responsible for removing the wet load. The sources of the wet load are two parts: ① the wet load of the outside air infiltrating into the space above the grain surface. ② the moisture brought into the upper part of the grain surface by the air microcirculation of the grain pile. Due to the setting of the grain pile temperature maintaining device, the intensity of the microcirculation is reduced. According to the actual operation experience, in the warehouse of the low-temperature unit, the relative humidity of the air in the upper space of the grain surface in summer is 65-75%.
[0035] For paddy rice, under the conditions of a warehouse temperature of 15°C and a relative humidity of 60%, the corresponding equilibrium moisture content of paddy rice is 14.3%. When the moisture content > 14.3%, the paddy rice will desorb and release wet load to the space above the grain surface, which generally occurs on the surface of the grain pile, and this load is not large. There is no air passing through the paddy rice pile, which can be regarded as automatic balance. The actual design is based on 15°C and a relative humidity of 70%, and the corresponding dew point temperature is about 9.6°C, and the equilibrium moisture content of rice is 15.7%.
[0036] The grain pile temperature maintaining device includes a refrigerant circulation system and a temperature measuring cable 4. The refrigerant circulation system includes a cooling coil 1, a refrigerant unit 2 and a flow distribution device 3. The flow distribution device 3 and the temperature measuring cable 4 are electrically connected to the control system. The cooling coil 1 and the temperature measuring cable 4 are evenly distributed on the inner wall of the warehouse and the floor 6 in direct contact with the grain pile. The refrigerant unit 2 is arranged outside the warehouse. The refrigerant unit 2 provides refrigerant for the cooling coil 1, and the refrigerant controls the flow rate of the refrigerant entering / leaving the cooling coil 1 through the flow distribution device 3; the control system automatically adjusts the refrigerant flow rate of the flow distribution device 3 according to the temperature real-time fed back by the temperature measuring cable 4, so as to control the temperature of the inner wall of the warehouse and the floor 6 within the set temperature value. The refrigerant temperature tw provided by the refrigerant unit 2 ≥ t1 + 2°C, and this setting prevents the refrigerant temperature tw from being lower than the dew point temperature t1 and causing condensation in the warehouse.
[0037] In this embodiment, the refrigerant is cooling water, the refrigerant unit 2 is an air-conditioning chilled water unit, and the flow distribution device 3 is a manifold. Of course, in other embodiments, the refrigerant can also be air or Freon, the refrigerant unit 2 is an air source heat pump or an air-conditioning unit, and the flow distribution device 3 is an air distributor or an expansion valve.
[0038] According to the dew point temperature \(t_l\), the supply water temperature \(t_w\) of the air-conditioning chilled water unit is determined as \(t_l + 2^{\circ}C\). The air-conditioning chilled water unit sends cooling water meeting a certain temperature accuracy into the distribution header. According to the difference between the temperature value feedback by the corresponding temperature measuring cable 4 laid in the inner wall of the bin and the floor 6 and the set temperature value, the corresponding regulating valve on the distribution header is adjusted to control the cooling water volume (i.e., control the temperature of the inner wall of the bin and the floor 6), and the chilled water is distributed to each cooling coil 1 of the inner wall of the bin and the floor 6. After the cooling water is heated up in the cooling coil 1, it returns to the distribution header and then flows to the air-conditioning chilled water unit, and after cooling, it circulates again.
[0039] As Figure 5 shown, the low-temperature bin includes a bin wall 5 and a floor 6. The bin wall 5 includes a decorative layer 51, an anti-cracking mortar layer 52, a mesh cloth layer 53, a thermal insulation layer 54, a leveling layer 55, a wall body 56, and a plastering layer 57 from the inside to the outside; the cooling coil 1 and the temperature measuring cable 4 are installed in the anti-cracking mortar layer 52. In this embodiment, the decorative layer 51 is coated with a food coating. The cooling coil 1 is installed inside the bin wall 5. One side in contact with the cooling coil 1 is the thermal insulation layer 54 (the thermal resistance of the outer wall is larger), and the other side is the decorative layer 51 with a very small thermal resistance. When the cold refrigerant coil accesses the flowing low-temperature refrigerant, the temperature of the inner wall of the bin is higher than the set temperature. Due to the temperature difference, heat is transferred into the decorative layer 51 and then into the cooling coil 1. After the refrigerant is heated up, it enters the refrigerant unit 2 installed outside the bin. After the refrigerant is cooled down to the set temperature \(t_w\), it enters the cooling coil 1 again, and this cycle ensures that the temperature of the inner wall of the bin is below the set temperature value.
[0040] The floor 6 includes a C25 concrete layer 61, a steel wire layer 62, a cement mortar layer 63, a thermal insulation layer 54, a waterproof layer 65, a leveling layer 55, a crushed stone cushion layer 67, and a rammed native soil layer 68 from top to bottom; the cooling coil 1 and the temperature measuring cable 4 are installed in the cement mortar layer 63.
[0041] Setting the cooling coil 1 in the bin wall 5 and the floor 6 can realize taking out the incoming heat to the outside of the bin, maintaining the temperature of the grain in contact with the inner wall of the bin and the floor 6 lower than the set temperature value, cooling the grain in contact with the inner wall of the bin and the floor 6, and ensuring the temperature control of the whole bin.
[0042] In this example, the thermal insulation layer 54 is an extruded polystyrene board, the leveling layer 55 is cement mortar, and the waterproof layer 65 is an ethylene propylene diene monomer (EPDM) polymer waterproof coil.
[0043] Of course, in other embodiments, the thermal insulation layer 54 can also be a polystyrene foam board or a polyurethane foam layer; the leveling layer 55 can also be a C15 concrete layer or a C20 concrete layer; the waterproof layer 65 can also be a polyvinyl chloride (PVC) waterproof coil or a polyurethane waterproof coating layer.
[0044] Based on the above description of this specification, those skilled in the art can also understand the following terms used, such as the terms indicating orientation or positional relationship, such as "upper", "lower", "inner", "outer", etc., which are based on the orientation or positional relationship shown in the drawings of this specification. It is only for the purpose of facilitating the description of the solution of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element involved must have the specific orientation, be constructed and operated in the specific orientation. Therefore, the above terms of orientation or positional relationship cannot be understood or interpreted as a limitation to the solution of the present invention.
[0045] In addition, in the description of this specification, the meaning of "a plurality of" is at least two, such as two, three or more, etc., unless otherwise specifically defined.
Claims
1. A bulk grain low-temperature warehouse with six sides actively controlled temperature, characterized in that: The invention comprises a grain surface temperature maintaining device, a grain pile temperature maintaining device and a control system. The grain pile temperature maintaining device comprises a refrigerant circulation system and a temperature measuring cable (4). The refrigerant circulation system comprises a cooling coil (1), a refrigerant unit (2) and a flow distribution device (3). The flow distribution device (3) and the temperature measuring cable (4) are electrically connected to the control system. The cooling coil (1) and the temperature measuring cable (4) are evenly distributed on the inner wall and floor (6) of the warehouse in direct contact with the grain pile. The refrigerant unit (2) provides refrigerant for the cooling coil (1). The refrigerant controls the flow of the refrigerant into / out of the cooling coil (1) through the flow distribution device (3). When the control system detects that the temperature in the warehouse is higher than the set temperature value, the grain surface temperature maintaining device and the grain pile temperature maintaining device are started. The grain surface temperature maintaining device is used to maintain the temperature of the upper part of the grain surface within the set temperature value; the grain pile temperature maintaining device automatically adjusts the refrigerant flow of the flow distribution device (3) according to the temperature fed back in real time by the temperature measuring cable (4), so that the temperature of the warehouse inner wall and the floor (6) is controlled within the set temperature value.
2. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 1, characterized in that: The grain surface temperature maintaining device comprises a temperature sensor, a circulating fan and a low temperature unit arranged on the upper part of the low temperature bin.
3. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 2, characterized in that: A dew point temperature sensor is provided in the low temperature unit to monitor the dew point temperature t1 of the grain surface air, and the dew point temperature sensor is electrically connected to the control system.
4. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 3, characterized in that: The refrigerant temperature tw ≥ t1 + 2°C provided by the refrigerant unit (2).
5. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 4, characterized in that: The refrigerant is cooling water, the flow distribution device (3) is a manifold, and the refrigerant unit (2) is an air-conditioning chiller.
6. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 1, characterized in that: The low-temperature warehouse comprises a warehouse wall (5) and a floor (6); the warehouse wall (5) comprises, from the inside to the outside, a finishing layer (51), an anti-cracking mortar layer (52), a mesh cloth layer (53), an insulation layer (54), a leveling layer (55), a wall (56) and a plastering layer (57); the cooling coil (1) and the temperature measuring cable (4) are laid on the anti-cracking mortar layer (52).
7. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 6, characterized in that: The floor (6) comprises, from top to bottom, a C25 concrete layer (61), a steel wire layer (62), a cement mortar layer (63), a thermal insulation layer (54), a waterproof layer (65), a leveling layer (55), a crushed stone cushion layer (67), and a rammed earth layer (68); the cooling coil (1) and the temperature measuring cable (4) are laid on the cement mortar layer (63).
8. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 6 or 7, characterized in that: The thermal insulation layer (54) is an extruded polystyrene board, a polystyrene foam board or a polyurethane foam layer; the leveling layer (55) is a cement mortar, a C15 concrete layer or a C20 concrete layer.
9. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 6, characterized in that: The finishing layer (51) is formed by coating with food paint.
10. A bulk grain low-temperature warehouse with six sides actively controlled temperature as claimed in claim 7, characterized in that: The waterproof layer (65) is an EPDM polymer waterproof coiled material, a polyvinyl chloride (PVC) waterproof coiled material or a polyurethane waterproof coating layer.