Heat recovery from industrial refrigeration

Cooling produces a heat source

A refrigeration plant rejects the heat removed from cold rooms plus compressor input. Some of that heat can serve hot-water or process duties directly. A heat pump can raise it further when the sink temperature is too high for direct recovery.

Protect the refrigeration duty

Heat recovery must not force excessive condensing pressure or compromise food temperatures. Seasonal ambient conditions, defrost and compressor sequencing all affect the available source. Controls should prioritise refrigeration safety while making useful heat when demand exists.

Count both sides carefully

Simultaneous heating and cooling can improve project economics but double counting is easy. Establish the baseline electricity and fuel use and define which cooling benefit is genuinely additional.

Start with the refrigeration heat balance

A refrigeration condenser rejects the cooling duty plus the compressor's electrical input. If a plant removes 1,000 kW from cold rooms while compressors draw 300 kW, condenser heat is roughly 1,300 kW before losses and auxiliary effects. That does not mean all 1,300 kW is available at one temperature.

Condensing pressure, refrigerant type, desuperheating potential and seasonal load determine the recoverable temperature profile. Raising condensing pressure solely to make hotter water can increase refrigeration electricity enough to weaken the overall case.

Choose between desuperheating and a heat pump

Desuperheating can recover a smaller quantity of relatively hot refrigerant heat directly. Condenser heat is larger but usually available at a lower temperature. A heat pump can upgrade that condenser stream when the process needs hotter water than direct recovery can provide.

The comparison must retain safe refrigeration control and enough heat rejection when the process sink is unavailable. A dry cooler, cooling tower or other rejection route may still be needed for summer peaks, cleaning shutdowns and low hot-water demand.

Good matches in Spanish food and drink plants

Cold stores, dairies, breweries, wineries and food processors may cool products or rooms while heating wash water, cleaning circuits, pasteurisation stages or drying air. The strongest opportunity is simultaneous operation at a manageable lift.

Daily timing matters. A refrigeration load that peaks while hot-water tanks are already full may need storage or a different sink. The feasibility model should use interval data from both utilities and production rather than assume that two annual totals coincide.