Exhaust Gas Heat Exchangers for CHP Plant

Exhaust Gas Heat Exchangers for CHP Plant

CHP plants generate both electricity and usable heat from a single fuel source (e.g., natural gas, biogas, or diesel). A large portion of the energy input (up to 30–50%) is lost as heat in exhaust gases, which can reach temperatures of 300–600°C (572–1,112°F) depending on the prime mover. EGHXs recover this waste heat, converting it into usable thermal energy (e.g., hot water, steam, or preheated air) for:

Space heating or domestic hot water (residential/commercial use).

Industrial processes (e.g., drying, sterilization, or heating in manufacturing).

Preheating combustion air or fuel (to improve prime mover efficiency).

Driving additional thermal cycles (e.g., organic Rankine cycles for extra power generation).

Exhaust Gas Heat Exchangers operate on the principle of indirect heat transfer:

Hot exhaust gases (typically 300–600°C) from the prime mover flow through one side of the heat exchanger.

A secondary fluid (e.g., water, thermal oil, or air) flows through the opposite side, separated by a heat-conducting surface (e.g., metal tubes or plates).

Heat from the exhaust gases transfers through the conducting surface to the secondary fluid, raising its temperature.

The cooled exhaust gases (typically reduced to 100–200°C) are then released to the atmosphere, while the heated secondary fluid is directed to end-use applications.