The brine solution has a lower condensation temperature, so it can be often used in medium-temperature and low-temperature chillers to carry cold energy. Usually, calcium chloride, magnesium chloride, and sodium chloride aqueous solutions are used. The condensation point of salt water depends on the concentration of salt water. As the concentration increases, the condensation point decreases. When the condensation point drops to a lower point, if the concentration increases again, the condensation point rises instead. Then, when brine is used as a low-temperature chiller refrigerant, how should the concentration of brine be mastered? Today I will work with you to analyze this problem.

If the concentration of the brine increases, the density of the brine increases, and the power consumption of the pump that transports the brine increases. If the specific heat capacity of the brine is reduced, the brine flow required to transport a certain cooling capacity will increase, and the power consumption of the pump will be increased. Therefore, the brine concentration should be chosen based on the criterion that the freezing point of the brine is lower than the lower temperature that can be exhibited in the refrigerant system.

At present, the common method is to select the concentration of brine so that the condensation point is 5-8°C lower than the evaporation temperature of the low-temperature chiller (if the water tank type evaporator is selected, take 5-6°C, and if the shell-and-tube type evaporator is selected, take 6-8°C °C). In view of this, the sodium chloride solution is only used in the refrigeration system with the evaporation temperature higher than -16℃, and the calcium chloride solution can be used in the refrigeration system with the evaporation temperature not lower than -50℃.