Pressure reducing variable expansion disc

A heat exchanger, comprising:

• a header;
• a tubular element configured to direct a flow of fluid toward the header;
• at least one temperature sensor;
• and
• an expansion disc assembly, comprising:
• a disc body comprising two or more leaves fluidly interposed between the tubular element and the header and configured such that the two or more leaves cooperatively assume a closed condition by a first shuttering action at which the disc body exclusively inhibits the flow, a fully open condition by a second shuttering action at which the disc body permits the flow and partial open conditions between the closed and full open conditions by third shuttering actions at which the disc body exclusively inhibits a portion of the flow;
• an actuator, which is controllable to cause the disc body to assume the closed, fully open and partial open conditions;
• and
• a control element configured to control the actuator based on readings generated by the at least one temperature sensor.

A method of operating a heat exchanger, comprising:

• fluidly interposing a disc body between a tubular element and a header,
• the disc body comprising two or more leaves fluidly interposed between the tubular element and the header and being configured such that the two or more leaves cooperatively assume a closed condition by a first shuttering action at which the disc body exclusively inhibits a flow of fluid from the tubular element to the header, a fully open condition by a second shuttering action at which the disc body permits the flow and partial open conditions between the closed and full open conditions by third shuttering actions at which the disc body exclusively inhibits a portion of the flow;
• and
• controlling the disc body to assume the closed, fully open and partial open conditions to achieve a target expansion of the flow of fluid.