Compressor assembly including a flow-restricting valve

A method of controlling fluid flow through a compressor housing having a first end and a second end opposite of the first end, the compressor housing having a suction inlet at the first end and a discharge outlet at the second end, the method comprising:

• providing a refrigeration circuit including at least a condenser, an expansion valve, a cooler, and a compressor;
• positioning the compressor within the compressor housing, the compressor comprising at least one rotating component positioned within the compressor housing between the suction inlet and the discharge outlet, and at least one magnetic bearing that supports the at least one rotating component in a manner that facilitates rotation of the at least one rotating component;
• placing a flow restricting valve in a position to control fluid flow through the discharge outlet, wherein the position is between the discharge outlet of the compressor housing and the condenser;
• allowing an unrestricted fluid flow in a first direction during a first operating condition, wherein the first operating condition corresponds to a normal or desired operation of the refrigeration circuit where the flow restricting valve is configured to allow the unrestricted fluid flow in the first direction into the compressor housing through the suction inlet and out of the discharge outlet;
• allowing a restricted fluid flow in a second, opposite direction during a second operating condition, wherein the second operating condition occurs immediately after a shutdown of the compressor, and wherein during the second operating condition the flow restricting valve is configured to only allow a restricted amount of fluid flow into the compressor housing of the compressor through the discharge outlet;
• wherein the flow restricting valve is external to the compressor housing and is immediately downstream of the discharge outlet when operating in the first operating condition;
• wherein the flow restricting valve is immediately upstream of the discharge outlet when operating in the second operating condition, and wherein the condenser is immediately downstream of the flow restricting valve when operating in the first operating condition;
• and
• wherein the refrigeration circuit includes a bypass path through which the fluid may flow as pressures in the condenser and cooler equalize, and including a valve configured to control whether fluid can flow through the bypass path, wherein the valve remains closed during the first operating condition, and wherein the valve is opened during conditions that may result in undesired backflow through the compressor during the second operating condition, and wherein the bypass path has a first connection to the refrigeration circuit at a location between the flow restricting valve and the condenser, and has a second connection to the refrigeration circuit at a location between a cooler and the suction inlet.

A compressor assembly, comprising:

• a compressor housing having a suction inlet and a discharge outlet;
• a compressor positioned within the compressor housing;
• a flow restricting valve that is configured to allow unrestricted fluid flow in a first direction into the compressor housing through the suction inlet and out of the discharge outlet during a first operating condition and to allow a restricted fluid flow in a second, opposite direction into the compressor housing through the discharge outlet in a second operating condition, and wherein the flow restricting valve is positioned within a refrigeration circuit between the discharge outlet and a condenser;
• wherein the second operating condition occurs immediately after a shutdown of the compressor, and wherein during the second operating condition the flow restricting valve is configured to only allow the restricted fluid flow into the compressor housing of the compressor through the discharge outlet;
• and
• wherein the refrigeration circuit includes a bypass path through which the fluid may flow as pressures in the condenser and cooler equalize, and including a valve configured to control whether fluid can flow through the bypass path, wherein the valve remains closed during the first operating condition, and wherein the valve is opened during conditions that may result in undesired backflow through the compressor during the second operating condition.