A maintenance-free dehumidifier and its control method

Abstract

A maintenance-free moisture absorber comprises a connecting flange, an upper connecting base, a condensation cover and an air inlet and outlet module, moisture absorbing silica gel, a heating device and a control box, wherein the connecting flange, the upper connecting base, the condensation cover and the air inlet and outlet module are sequentially connected; the moisture absorbing silica gel and the heating device are arranged in the condensation cover; and the control box is positioned outside the condensation cover. A breathing tube communicated with the connecting end of the air inlet and outlet module through the moisture absorbing silica gel is arranged in the moisture absorbing silica gel, a condensation cavity is positioned in the upper connecting base, one end of the condensation cavity defined by an air duct is communicated with the top end of the breathing tube, and the other end of the condensation cavity is communicated with a flange opening of the connecting flange. A semiconductor refrigeration piece and a radiator are symmetrically arranged on the outer portion of the air duct, and the semiconductor refrigeration piece is connected to the refrigeration control end of the control box. A method for controlling the maintenance-free moisture absorber comprises collecting color information of the moisture absorbing silica gel in real time; comparing an RGB value at the set comparison moment and position on the day and a set RGB value; if the RGB value at the set comparison moment and position on the day is larger than the set RGB value, setting a night dehydration control mark, first starting to perform refrigeration and then performing heating; after the reduction process of the moisture absorbing silica gel is ended, first stopping heating and then stopping refrigeration; or else resetting.

Description

technical field [0001] The invention relates to a moisture absorber for a transformer oil conservator, in particular to a maintenance-free moisture absorber and a control method thereof. Background technique [0002] Hygroscopic silica gel is used as an air humidity filter material to filter the vent holes on the transformer oil conservator, mainly to filter out moisture and dust in the air. Use color-changing silica gel to judge whether the hygroscopic material is invalid by observing with human eyes. In the past, if 1 / 3 of the silica gel was found to be discolored, it was necessary to replace it with a new silica gel. The expired silica gel can only be disposed of. [0003] In response to the above problems, the German MR company has developed a device that automatically restores invalid silica gel through online heating, named it a maintenance-free dehumidifier. Most people think that the silica gel is invalid, and start the heating device to heat and dehydrate the silic...

AI Technical Summary

Problems solved by technology

MR company's maintenance-free dehumidifier has the following problems. 1. Judging the failure of silica gel through humidity detection is an indirect method, and there is a problem of inaccurate identification. If the humidity of the outside air is not high, even after filtering the invalid silica gel Its humidity is also very small, so the equipment thinks that the silica gel is effective, which is a mistake

2. The air intake and outlet of the vent hole of the transformer oil conservator change in real time along with the thermal expansion and contraction of the oil, and the thermal expansion and contraction of the oil changes with the transformer load, and there is no rule to follow

This will cause the possibility that hot and humid steam will be sucked into the transformer oil conservator when the silica gel is being heated and dehydrated, further threatening the reliable operation of the transformer

3. The air intake and outlet part of the maintenance-free dehumidifier adopts the structure of metal sintered mesh, which plays the role of filtering air dust, but the breathing state cannot be observed. The original traditional dehumidifier is equipped with an oil cup. When exhaling and inhaling There will be air bubbles, and the transformer user can observe this phenomenon, which is helpful to judge whether the air hole of the oil conservator is unblocked, because once the air hole is blocked, the gas relay will malfunction, and then the transformer will be cut off.

After statistical analysis by users, COMEN's maintenance-free dehumidifier also has several problems. 1. The measurement accuracy of the load cell is limited by the ambient temperature and the vibration of the transformer itself during operation. The weight change after the silica gel absorbs moisture is Trace level, silica gel can be judged by weighing whether it is saturated with moisture The principle is limited to the laboratory environment

2. When the maintenance-free dehumidifier with double-tube structure is used in a large-capacity transformer, the volume is too large, which is not conducive to design and installation

3. The breathing state is still unobservable

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