Refrigerant removal in supermarket refrigerated showcase (2)

The operation methods and steps for removing ammonia and fluorine from the refrigeration system of supermarket refrigerated showcase are described below.

1. The refrigeration system takes ammonia

(1) Prepare a certain number of ammonia bottles, scales, ammonia taking tools, labor protection supplies and operating tools.

(2) Start the refrigeration system for refrigeration according to the normal procedure, so that the cold capacity is accumulated in the evaporator water tank. Close the throttle valve gradually. When the water temperature in the evaporator tank is close to 0°C, close the expansion valve to keep the evaporator pressure at about 0.098MPa, and stop the refrigeration system.

(3) Before stopping the refrigeration system of the supermarket refrigerated showcase, turn off the condenser cooling water and increase the condensing pressure to about 1.25MPa.

(4) After stopping, the evaporation pressure should not rise, otherwise the compressor must be started to pump ammonia again to the evaporator.

(5) Lead the low-temperature water in the evaporator water tank, pour it on the ammonia bottle placed in the tank, and often agitate the low-temperature water in the tank to cool the ammonia bottle evenly. Then open the main liquid supply valve, the ammonia filling valve and the ammonia cylinder valve. The refrigerant in the ammonia cylinder is cooled by the low temperature water, and the corresponding saturation pressure is not high. In this way, the pressure in the ammonia cylinder and the pressure of the reservoir form a pressure If there is a difference, the liquid ammonia in the reservoir will quickly enter the empty ammonia bottle under the pressure of the pressure difference. In the process of extracting ammonia, the quality of liquid ammonia entering the ammonia bottle should be strictly controlled (usually weighed by a scale), and generally should not exceed 60% of the volume of the supermarket refrigerated showcase ammonia bottle. If the ammonia bottle is filled with liquid ammonia, when the ammonia bottle is taken out of the low temperature water, the pressure in the ammonia bottle will rise quickly due to the influence of the ambient temperature higher than the low temperature water. In addition, there is no room for expansion in the bottle, the result is more dangerous of.

(6) After the ammonia bottle is filled with the specified quality, close the ammonia filling valve and the ammonia bottle valve, replace with another bottle and extract until the pressure in the reservoir drops to the saturation pressure when the ammonia bottle is cooled by low temperature water When equal, it can be considered that the refrigeration system has finished taking the amino group. The remaining part of the system is ammonia gas and its oily impurities, which can be put into the sewer through the emergency ammonia discharge device or the lowest point in the system, or diluted with water into ammonia water as fertilizer.