A method for optimizing defrosting control of a dual-fifteen drying chamber dehumidifier

Abstract

The present application relates to a kind of double fifteen dry room dehumidifier defrosting control optimization method, for optimizing control double fifteen warehouse refrigeration system, the refrigeration system includes two indoor units and a set of outdoor unit, outdoor unit contains two sets of compression condensing unit, two sets of compression condensing unit is connected after parallel connection with two indoor units in warehouse, during defrosting by adjusting the electromagnetic valve of indoor unit, fan and the start-up sequence of compressor of outdoor unit, simultaneously adjusting the start-stop point of two-stage energy regulation of compressor, control the suction pressure of compression condensing unit, ensure that suction pressure is always lower than required value, make the fluctuation of humidity during defrosting greatly reduce, improve the dehumidification effect of compression condensing unit.The present application can ensure quick and efficient defrosting by adjusting control strategy during defrosting, and can reduce the influence of defrosting on warehouse humidity.

Description

Technical Field

[0001] This invention relates to a refrigeration technology, dehumidification technology, and control technology, and in particular to a refrigeration and dehumidification device suitable for high humidity control requirements. Background Technology

[0002] In the long-term preservation of crop seeds, drying and dehydration is a crucial step. This process is typically completed in a double-15°C room (room temperature and humidity required to be 15%), where the air moisture content is only 1.57 g / kg and the dew point temperature is approximately -10°C. Due to the high temperature and humidity requirements, two common dehumidification methods are rotary dehumidification and refrigeration dehumidification. Rotary dehumidifiers require high maintenance, have a short rotor lifespan, require real-time high-temperature regeneration during operation, and consume a lot of energy. This project uses a refrigeration dehumidification principle to design equipment that utilizes condensation heat to reheat the air. Compared to rotary dehumidifiers, this significantly reduces energy consumption and simplifies subsequent maintenance. Part of the condensation heat is used in the reheat coil to reheat the dehumidified air, and the other part is used in the dehumidification coil for hot air defrosting. In actual operation, it was found that the humidity would periodically rise sharply along with the frequency of defrosting, leading to unstable humidity in the storage room and affecting seed drying. Summary of the Invention

[0003] The purpose of this invention is to propose an optimized defrosting control method for a dual-fifteen drying chamber dehumidifier. Without adding auxiliary dehumidification equipment, this method improves the situation of a significant increase in humidity during defrosting by optimizing the control logic and algorithm of the existing dual-fifteen drying dehumidifier during defrosting.

[0004] To achieve the above objectives, the technical solution of the present invention is: a defrosting control optimization method for a dual-15 drying chamber dehumidifier, used to optimize the control of the refrigeration system of a dual-15 warehouse. The refrigeration system includes two indoor units and one outdoor unit. The outdoor unit contains two sets of compressor-condensing units. The two sets of compressor-condensing units are connected in parallel and connected to the two indoor units in the warehouse. During defrosting, by adjusting the start-up sequence of the solenoid valves and fans of the indoor units and the compressor of the outdoor unit, and simultaneously adjusting the start-stop points of the two-stage energy regulation of the compressor, the suction pressure of the compressor-condensing units is controlled to ensure that the suction pressure is always lower than the required value, thereby significantly reducing the humidity fluctuation during defrosting and improving the dehumidification effect of the compressor-condensing units.

[0005] Furthermore, the optimized defrosting control method for the dual-fifteen drying chamber dehumidifier specifically includes:

[0006] (3) When the compressor condenser unit enters the dehumidification mode, both the indoor and outdoor units are put into operation. During the process, the control program automatically calculates the cumulative time based on the running time. When the defrosting time is up, the two indoor units defrost in sequence.

[0007] (4) After entering the defrost mode, the fan of one indoor unit stops running, the liquid supply line is cut off, the defrost gas supply line is opened, and the other indoor unit operates normally for cooling. During the defrost period, the two compressors operate by increasing or decreasing load according to the suction pressure, and control the suction pressure range to 0.4 to 0.8 MPa.

[0008] Furthermore, the specific steps of the method of the present invention are as follows: When the suction pressure is greater than 0.8MPa, compressor No. 1 performs first-stage unloading; the suction pressure is judged after a delay, and if the suction pressure is still higher than 0.8MPa, compressor No. 1 performs second-stage unloading; after running for a period of time, it is judged again, and if the suction pressure is still high, compressor No. 1 stops running; after compressor No. 1 stops running, compressor No. 2 automatically judges and runs according to the same logic. If the suction pressure recovers during this period, the corresponding unloading action is restored to the corresponding loading action. Based on the cumulative running time, the compressor with the longer running time is given priority to start the unloading action; after defrosting, the solenoid valve of the liquid supply pipeline in the indoor unit is turned on, and the fan is turned on again after 5 seconds to cool and condense the trace residual moisture that has not been discharged from the dehumidified coil, so as to avoid it being carried into the room after the fan is turned on. The very few crystals formed by this trace moisture will be removed in the next defrosting cycle.

[0009] The beneficial effects of this invention are:

[0010] This invention, by adjusting the control strategy during defrosting, can ensure rapid and efficient defrosting while reducing the impact of defrosting on warehouse humidity. Attached Figure Description

[0011] Figure 1 This is a diagram of the refrigeration system of the present invention;

[0012] Figure 2 This is the room relative humidity sampling curve before the defrosting control method was optimized;

[0013] Figure 3 This is the room relative humidity sampling curve after the defrosting control method of the present invention is optimized. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] like Figure 1 As shown, the refrigeration system of this invention includes two indoor units and one outdoor unit. The outdoor unit includes two compressor-condenser units, which are connected in parallel and then connected to the two indoor units inside the warehouse. (See attached diagram.) Figure 1 .

[0016] When the unit enters dehumidification mode, both indoor and outdoor units are fully operational. During this process, the control program automatically calculates the accumulated running time. When the defrost time arrives, both indoor units defrost sequentially. Upon entering defrost mode, the fan of one indoor unit stops, the liquid supply line is cut off, and the defrost gas supply line is opened, while the other indoor unit continues normal cooling. During defrost, both compressors operate under load and unload conditions based on the suction pressure, controlling the suction pressure range between 0.4 and 0.8 MPa. The specific process is as follows: When the suction pressure is greater than 0.8 MPa, compressor #1 performs a first-stage unloading; after a delay, the suction pressure is assessed again. If the suction pressure remains higher than 0.8 MPa, compressor #1 performs a second-stage unloading; after a period of operation, the suction pressure is assessed again. If the suction pressure is still high, compressor #1 stops operating. After compressor #1 stops operating, compressor #2 automatically starts operating according to the same logic. If the suction pressure recovers during this period, the corresponding unloading action reverts to the corresponding loading action. Based on the accumulated running time, the compressor with the longer running time is prioritized for unloading. After defrosting, the solenoid valve of the liquid supply line in the indoor unit is activated, and the fan turns on again after 5 seconds. This cools and condenses any remaining trace amounts of moisture on the dehumidified coils, preventing it from being carried into the room when the fan starts. The very few crystals formed from this trace amount of moisture will be removed in the next defrosting cycle.

[0017] This invention provides a control logic that, during defrosting, adjusts the start-up sequence of the indoor unit's solenoid valve, fan, and outdoor compressor, while simultaneously adjusting the start-stop points of the compressor's two-stage energy regulation to control the unit's suction pressure. This ensures that the suction pressure remains below the required value, significantly reducing humidity fluctuations during defrosting and resulting in better dehumidification performance.

[0018] This invention, by adjusting the control strategy during defrosting, can ensure rapid and efficient defrosting while reducing the impact of defrosting on warehouse humidity. A comparison of warehouse humidity sampling curves before and after the control strategy improvement is shown below. Figure 2 , 3 .

Claims

1. A method for optimizing defrost control of a two-stage desiccant dehumidifier system, comprising the steps of: The application discloses a method for optimizing the control of a refrigeration system of a double-fifteen warehouse, wherein the refrigeration system comprises two indoor units and an outdoor unit, the outdoor unit comprises two sets of compression-condensing units, the two sets of compression-condensing units are connected with the two indoor units in parallel, during defrosting, the opening sequence of electromagnetic valves, fans and compressors of the outdoor unit is adjusted, the start-stop points of two-stage energy regulation of the compressors are adjusted, the suction pressure of the compression-condensing units is controlled, the suction pressure is ensured to be always lower than a required value, the fluctuation of humidity during defrosting is greatly reduced, and the dehumidification effect of the compression-condensing units is improved. ​ 2. The dual-fifteen desiccant dehumidifier defrost control optimization method of claim 1, wherein: The defrosting control optimization method of the double-fifteen drying room dehumidifier specifically comprises the following steps: (1) when the compression-condensing units enter a dehumidification working condition, the indoor units and the outdoor unit are all put into operation, during the process, a control program automatically accumulatively calculates according to running time, when the defrosting time arrives, the two indoor units are defrosted in turn; (2) after entering a defrosting mode, the fan of one indoor unit stops running, the liquid supply pipeline is cut off, the defrosting gas supply pipeline is opened, and the other indoor unit normally runs refrigeration; during defrosting, the two compressors are operated according to the suction pressure to control the suction pressure range to be 0.4-0.8 MPa.

3. The dual-fifteen desiccant dehumidifier defrost control optimization method of claim 2, wherein: The specific steps of the method are as follows: when the suction pressure is greater than 0.8 MPa, the first-stage unloading of No. 1 compressor is performed; the suction pressure is judged after a time delay, if the suction pressure is still higher than 0.8 MPa, the second-stage unloading of No. 1 compressor is performed; after a period of operation, the suction pressure is judged again, if the suction pressure is still high, No. 1 compressor stops running; after No. 1 compressor stops running, No. 2 compressor is automatically judged and operated according to the same logic, if the suction pressure is restored, the corresponding unloading action is restored to the corresponding loading action, according to the accumulated running time, the compressor with a longer running time is preferentially started to perform the unloading action; after defrosting is completed, the liquid supply pipeline electromagnetic valve in the indoor unit is connected, the fan is started after 5 seconds, the trace of residual moisture on the dehumidified coil is condensed to avoid the trace of residual moisture being brought into the room after the fan is started, and the few crystals formed by the trace of residual moisture are removed in the next defrosting cycle.

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