Thread Content
During the operation of the cooling water system in a chiller, as heat is dissipated through evaporation in the open-type cooling tower, the salinity of the circulating cooling water gradually increases. When the concentration reaches a level at which calcium and magnesium ions precipitate, scale begins to form. The cooling water inside the copper tubes of the condenser is used to remove heat from the high-pressure, high-temperature refrigerant side. In simple terms, the more heat that is removed by the cooling water side, the more stable the temperature difference in the condenser remains. Once the condenser is selected, the amount of heat removed by its cooling water side depends on the flow rate of the cooling water inside the heat exchange copper tubes as well as the cleanliness of the inner walls of these tubes. When the temperature difference for heat exchange on both sides of the copper tubes is large and the flow rate of the water is low, scale is likely to form. This scale gradually becomes harder and thicker, leading to the accumulation of dirt over time. Scale has a high fouling coefficient, resulting in a heat transfer efficiency that is far lower than that of copper tubes. The heat on the condensation side cannot be transferred to the cooling side, causing the temperature difference across the condenser to increase gradually; however, when this difference reaches the set limit of the main unit, an alarm is triggered. To address the issue of low temperature difference alarms in the condenser, maintaining the cleanliness of the inner surface of the copper tubes used for heat exchange is the most important task to undertake. The formation of scale is a result of prolonged operation of the main unit; therefore, cleaning these areas promptly when the scale is still in its early, less dense stage can help keep the inner surface of the copper tubes clean. The Qinyuan WSA brush online cleaning system enables the online cleaning of the inner walls of copper pipes, without the need to shut down the main unit. The four-way directional control valve attached to it changes the direction of the water flow every 4–6 hours, allowing the brush to clean each copper pipe individually and thoroughly. This technology is mature and reliable, and it has been widely used in the domestic air conditioning and refrigeration industry.