Patent ID: 9746218
Date: 2017-08-29
CPC Classifications: F25B

Claim:
1. A refrigeration system comprising: a condenser, an evaporator, an economizer, and a main compressor fluidly connected by a main refrigerant line to form a main refrigerant circuit; an expansion device connected to the main refrigerant line intermediate the condenser and the economizer; an auxiliary compressor, the auxiliary compressor being separate and distinct from the main compressor and independently controllable at all times with respect to the main compressor, the auxiliary compressor being capable of being operated at a different speed than the main compressor; an auxiliary refrigerant line fluidly connecting the economizer to the auxiliary compressor and fluidly connecting the auxiliary compressor to the main refrigerant line at a location intermediate the main compressor and the condenser to form an economizer refrigerant circuit, wherein the auxiliary compressor is configured to compress refrigerant flowing through the economizer refrigerant circuit; and a controller configured to adjust an economizer pressure based on a comparison of an estimated power usage of a version of the refrigeration system without the economizer and an estimated power usage of the refrigeration system with the economizer; wherein the economizer is positioned at a junction between the main refrigerant line and the auxiliary refrigerant line, the junction in fluid communication with the main refrigerant line and the auxiliary refrigerant line; wherein all refrigerant flowing in the main refrigerant line from the condenser flows through the expansion device and enters the economizer in a single flow prior to a first portion of the refrigerant entering the evaporator, and prior to a remaining portion of the refrigerant entering the auxiliary compressor, each of the first portion of the refrigerant and the remaining portion of the refrigerant being greater than zero at all times during operation of the system.