Використання СО2 у системах холодопостачання торговельних підприємств

Abstract

Розглянуто інженерні рішення холодильних схем, що найчастіше застосовуються під час проектування централізованих систем холодопостачання на СО2. Досліджено переваги, недоліки та шляхи підвищення ефективності систем холодопостачання торговельних підприємств із застосуванням СО2.

In the article we examined the ways of using cooling systems for different food companies in which CO2 used as a coolant. We made analytical examination of engineering decisions of cooling for trade enterprises which use CO2 (in subcritical and supercritical cycles) Was found that cooling systems which use CO2 are more effective than systems with synthetic refrigerants if they work at subcritical temperatures. This systems have such benefits: high temperature level require a small amount of refrigerant; temperature difference near cascaded heat exchanger is relatively low; on the side of high pressure of the different cooling systems we can use freon or ammonia; cascaded system with ammonia-carbon dioxide as a refrigerant has the highest efficiency. The advantage of transcritical cooling systems with CO2 is ability to effective using of heat recovery for getting hot water for technological needs. Systems that use CO2 have no problem with getting potential heat unlike freon systems. All heat of the work has high potential, all overheat can be used. A common problem for both subcritical systems, and for transcritical is growth of pressure in system downtime. To solve this problem, there are several ways: to maintain pressure in the refrigeration unit at a reasonable level, you can use additional small refrigerators; install in the system expansion vessel, sufficient to offset growth of pressure in system downtime; design the system in the way it can withstand the pressure of downtime (pressure of saturated vapor at room temperature) is 80 bar.