Carbon dioxide brine production system for use in an ammonia refrigeration system using liquefied carbon dioxide as heat transfer medium

摘要

The object of the invention is to provide a CO2 brine production system comprising apparatuses working on an ammonia refrigerating cycle, a brine cooler (3) for cooling and condensing CO2 by utilizing the latent heat of vaporization of the ammonia, and a liquid pump (5) provided in a supply line (52) for supplying the cooled and liquefied CO2 to a refrigeration load side (6). Said liquid pump is a variable-discharge pump for allowing C02 to be circulated forcibly. The CO2 brine production system further comprises: a controller for controlling the liquid pump (5) to vary its discharge based on at least one of the detected signals of the temperature or pressure in a cooler provided to the refrigeration load side or pressure difference between the outlet and inlet of the pump; a supercooler (8) to supercool at least a part of the liquid CO2 in a liquid reservoir (4) provided for reserving the cooled and liquefied CO2 based on the condition of cooled state of CO2 in the liquid reservoir (4) or in the supply line; and a pressure sensor (P3) provided for detecting a pressure difference between the outlet and inlet of said liquid pump, wherein the conditions of cooling of CO2 is judged based on the signal from said pressure sensor.