4. Integrating heat pumps into industrial processes for heat production

4.1 Heat pump principle

A heat pump is a device for transferring thermal energy from a low-temperature medium (cold source) to a high-temperature medium (hot source). This device therefore reverses the natural direction of spontaneous thermal energy transfer. Depending on the operating direction of the pumping device, a heat pump can be regarded as a heating system, if the temperature of the hot source is to be increased, or as a refrigeration system, if the temperature of the cold source is to be lowered. For heat production, the process differs from conventional heating, in which a body is heated (by Joule effect, combustion, or any other process). When the pumping device provides simultaneous heating and cooling, the system is called a thermo-frigopump.

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