The hot water generating component of a geothermal system is called adesuperheater. It is merely a pump and a heat exchanger that is plumbed in such a way so as to carry waste heat away from the refrigeration cycle and into your water heater.
Maniks has a wide range of desuperheaters as they provide precise refrigerant temperature control for various applications in boilers, chemical, oil & gas process plants, etc where the available refrigerant is at superheated conditions.
The general intention of this device is to provide effective and continuous heat transfer between gas and water. And very very effective desuperheater application and design says that costly problems to be avoided, which includes general wear of downstream piping and equipment, long startup and shutdown times, and reduced process efficiency.
http://www.maniks.com/desuperheater.html
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