Closedcycle

Closedcycle is a designation used across several fields to describe systems that operate in a closed loop, recirculating materials or energy with minimal net exchange with the surrounding environment. The concept contrasts with open-cycle systems, in which inputs and outputs are not reused within the same loop.

In thermodynamics, a closed-cycle (or closed-loop) system refers to a process where the working fluid remains within a sealed loop and is continually recirculated. Common examples include the closed Brayton cycle, the closed Rankine cycle, and the Organic Rankine Cycle. These cycles are used in power generation, propulsion, and waste-heat recovery because they can improve efficiency by limiting leakage and allowing precise control of the working fluid.

In refrigeration and air conditioning, closed-cycle systems circulate refrigerants within a sealed circuit. The refrigerant absorbs and rejects heat through phase changes while remaining contained, reducing environmental releases and enabling compact, controllable cooling.

In environmental engineering and manufacturing, closed-cycle or closed-loop approaches aim to recover, reuse, and recycle materials and water to minimize waste and resource consumption. This perspective is central to the circular economy, where products are designed for repeated reuse and components are recovered at end of life.

Key considerations for closedcycle systems include containment integrity, purity of the circulating medium, energy requirements for pumps or compressors, and the potential consequences of leaks or fouling. Related topics include circular economy, life-support systems, and energy recovery technologies.