A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

A refrigerant compressor group for a refrigeration system, comprising at least two piston compressors that operate in parallel between a common low-pressure connector and a common high-pressure connector, wherein, for the purpose of adjusting it to different requirements, it is provided, in a refrigerant compressor group, for a variable overall mass flow throughput in the refrigerant compressor group to be adjustable in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by speed selection with the aid of a frequency converter for the electric motor, and in that, in the case of at least one of the piston compressors, its mass flow throughput is adjustable by cylinder selection, and in that an operating condition controller for the refrigerant compressor group is provided which, on the basis of a performance request signal of the refrigeration system that is transmitted to the operating condition controller, controls the overall mass flow throughput by open or closed-loop control by predetermining the cylinder selection and the speed selection.

A refrigeration system is provided and includes a common suction line, a common discharge line, first and second high-side compressors disposed in parallel to receive low-pressure refrigerant from the common suction line and to direct high-pressure refrigerant to the common discharge line, a first pipe connected to the first and second high-side compressors at vertical heights at which an oil supply is required to remain higher and a second pipe connected to the first and second high-side compressors at vertical heights sufficient to maintain gas pressure balance between the first and second high-side compressors.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

A system includes a pressure exchanger (PX). The PX is coupled to a motor that controls an operating speed of the PX. The system further includes a first pressure gauge configured to generate first pressure data indicative of a pressure of a fluid of a condenser. A first controller is to generate a first control signal based on the first pressure data. The motor of the PX is configured to adjust the operating speed of the PX based on the first control signal. The system further includes a pump. The system further includes a fluid density sensor for generating fluid density data associated with a first output fluid of the PX. A second controller is to generate a second control signal based on at least the fluid density data. The pump is to adjust an operating speed of the pump based on the second control signal.

A climate-control system may include a first compressor, a second compressor, a suction manifold, and a flow restrictor. The first and second compressors each include a shell and a compression mechanism. The shells define suction chambers from which the compression mechanisms draw working fluid. The shells include suction inlet fittings through which working fluid is drawn into the suction chambers. The suction inlet fittings are fluidly connected to the suction manifold. The suction manifold provides suction-pressure working fluid to the suction inlet fittings of the first and second compressors. The flow restrictor may be at least partially disposed within the suction manifold.

A heating and cooling system that includes a condenser coil configured to receive a refrigerant. A first compressor and a second compressor that pump the refrigerant through the condenser coil. A first condenser fan and a second condenser fan that push air over the condenser coil. A controller that receives a signal indicative of an ambient air temperature, a signal indicative of an operational status of the first compressor, and a signal indicative of an operational status of the second compressor. The controller controls operation of the first condenser fan and the second condenser fan in response to the signal indicative of the ambient air temperature, the signal indicative of the operational status of the first compressor and the signal indicative of the operational status of the second compressor.

A plurality of scroll compressors with different fixed volume indexes are connected in fluid parallel circuit and configured to selectively operate to maximize isentropic efficiency at different condensing temperatures. Different quantities of scroll compressors of different volume indexes may be selected based upon typical climate or geographic location environmental conditions to attempt to maximize efficiency. A controller may selectively operate different combinations of the compressors of different volume indexes bases up load demands and condensing temperature conditions, which may be determined in a variety of ways.

An integrated system floods an air conditioning low side heat exchanger such that the air conditioning low side heat exchanger does not evaporate all the liquid refrigerant entering the air conditioning low side heat exchanger. As a result, both liquid and vapor refrigerant leave the air conditioning low side heat exchanger. The system includes an additional receiver that stores the refrigerant leaving the air conditioning low side heat exchanger. To prevent the liquid refrigerant in the receiver from overflowing, the liquid refrigerant in the receiver is used in a refrigeration system when the level of liquid refrigerant in the receiver exceeds a threshold (e.g., as detected by a sensor in the receiver).

A method and system for improving energy efficiency of a refrigeration system include system components such as a condenser, one or more expansion valves, an evaporator, one or more compressors, and a system controller electrically coupled to the one or more of the system components, according to one embodiment. The system controller is configured to selectively actuate, directly or indirectly, the one or more expansion valves, the condenser, and/or the one or more compressors, at least partially based on temperatures and/or pressures of the system fluid at various points of the system, to control a temperature of a refrigerated area.