SECURING OF A STEADY OPERATION OF A LARGE-SCALE AMMONIA REFRIGERATION PLANT WITH AN AIR-COOLED CONDENSER

Abstract

The efficiency of a large-capacity ammonia refrigeration plant (ARP) with an air condenser depends on many factors. Changes in some of them in the condenser with a collector circuit lead to additional hydraulic resistances within the system. They are caused by ambient temperature changes, the accumulation of non-condensable gases in the system, the design features of the condenser and the uneven distribution of ammonia in the condenser coils. All this causes a pressure increase in the condenser and, consequently, excess demand energy, which is explained by the presence of non-condensable gases (NCG) in the system. The latter, in its turn, leads to the unnecessary more frequent opening of NCG relief valves, which results in a significant loss of ammonia. The reasons for the emergence of additional hydraulic resistances on the example of large-capacity ARP have been researched. The basic reasons for changing the operating parameters of the refrigeration unit, indicating the presence of NCG or the occurrence of resistance in the hydraulic system, worsening the drain of liquid ammonia from the condenser to the receiver have been determined. In order to stabilize the operation of ARP with an air cooled condenser and to reduce the resulting hydraulic resistance, as well as ammonia losses, we have developed and explained new algorithms of gas flaring and operating modes of air cooling fans that reduce the loss of ammonia by 10 times and the hydraulic resistance in the air condenser by 30 kPa.