Refrigeration system and method of use with a receiver tank and expander-assisted cooling

A method of operating a refrigeration system, the method comprising:

• cooling a refrigerant using a first high side heat exchanger;
• reducing a pressure of a first portion of the refrigerant received from the first high side heat exchanger using a first expansion valve;
• separating the refrigerant received from the first expansion valve into a liquid refrigerant and a vapor refrigerant using a receiver tank;
• cooling a first space with the liquid refrigerant received from the receiver tank using a first low side heat exchanger;
• recycling the refrigerant exiting the first low side heat exchanger to the receiver tank;
• reducing the pressure of a second portion of the refrigerant received from the first high side heat exchanger using an expander of an expansion-compression unit;
• and
• compressing the vapor refrigerant exiting the receiver tank using a compressor of the expansion-compression unit.

A refrigeration system, comprising:

• a first high side heat exchanger configured to receive refrigerant, the first high side heat exchanger configured to cool the refrigerant;
• a first expansion valve positioned downstream of the first high side heat exchanger, the first expansion valve configured to receive a first portion of the refrigerant from the first high side heat exchanger, and wherein the first expansion valve is configured to reduce a pressure of the refrigerant received from the first high side heat exchanger;
• a receiver tank positioned downstream of the first expansion valve, the receiver tank configured to receive the refrigerant from the first expansion valve, wherein the receiver tank is configured to separate the refrigerant into a vapor refrigerant and a liquid refrigerant;
• a first low side heat exchanger unit positioned downstream of the receiver tank, the first low side heat exchanger unit comprising a first low side heat exchanger configured to receive the liquid refrigerant from the receiver tank, wherein the first low side heat exchanger is configured to cool a first space proximate the first low side heat exchanger, and wherein the refrigerant exiting the first low side heat exchanger is recycled back to the receiver tank;
• a controllable valve positioned downstream of the first high side heat exchanger;
• a flash tank positioned downstream of the controllable valve, wherein the flash tank is configured to receive the refrigerant from the controllable valve, wherein the flash tank is configured to separate the refrigerant into a second vapor refrigerant and a second liquid refrigerant;
• a controller communicatively coupled to the controllable valve, the controller configured to transition the controllable valve between an open position and a closed position, wherein the controller is configured to:
• (i) direct a flow of the refrigerant received to the flash tank when the controllable valve is positioned in the open position;
• and
• (ii) direct the first portion of the refrigerant to the first expansion valve when the controllable valve is positioned in the closed position;
• an expansion-compression unit positioned downstream of the first high side heat exchanger and the receiver tank, the expansion-compression unit comprising:
• an expander configured to receive a second portion of the refrigerant from the first high side heat exchanger, wherein the expander is configured to reduce a pressure of the second portion of the refrigerant;
• and
• a compressor configured to compress the vapor refrigerant received from the receiver tank.