METHOD AND APPARATUS FOR STAGED STARTUP OF AIR-COOLED LOW CHARGED PACKAGED AMMONIA REFRIGERATION SYSTEM

摘要

Apparatus for staged startup of air-cooled low charged packaged ammonia refrigeration system includes motorized valves on condenser coil inlets, a main compressor discharge motorized valve, a bypass pressure regulator valve in the main compressor piping, check valves on the condenser outlets and speed control of the condenser fans. The condenser inlet motorized valves provide precise control of gas feed to the condensers, so pressure can build without collapsing the oil pressure. The condenser coil outlet contains inline check valves to prevent liquid backflow when a coil is isolated. The compressor discharge line contains a single motorized valve for regulating discharge pressure at start-up. The motorized valve in the compressor discharge piping also includes a bypass with a mechanical pressure regulator to allow precise regulation at the minimum discharge pressure. Once discharge pressure rises above the minimum setpoint, the condenser inlet solenoid coils will open one at a time. The discharge pressure regulating motorized valve will simultaneously regulate the discharge pressure until the condenser coil has warmed up enough to maintain discharge pressure.