Oilon ESi 6-17, Installation And Operation Manual

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1.4 System structure and operation
Ground source heating system
Ground source heat pump system ver. 1
Principle drawing of a ground source heating system.
1: brine circuit (horizontal ground loop, borehole or lake/pond system); 2: ground source heat pump;
3: heating circuits (radiator heating or floor heating); 4: domestic hot water heating; 5: passive cooling
(optional).
A ground source heat pump can extract thermal energy (heat) from soil, bedrock, or a
body of water. Of the total energy required for heating, a heat pump collects more than
75% from natural sources. Running the heat pump and the various system components
requires electricity, which means that the remaining 25 percent is electrical power
consumed by the process of extracting thermal energy.
A ground source heat pump system has three main components: the brine circuit,
the compressor unit (the actual heat pump), and the heating circulation. The three
circulations are isolated from each other, which means that none of the fluids used
(brine, refrigerant, and water) are mixed together at any part of the process. Instead,
heat is transferred between the fluids using plate heat exchangers.
Brine circuit
When the sun heats up the earth, thermal energy is stored in the soil, the bedrock,
and in bodies of water. To extract this heat, the ground source heat pump circulates a
cold mixture of water and ethanol ( brine ) inside a long loop of pipe embedded in the
earth
(the brine circuit
). As the brine passes through the brine circuit, its temperature
6 (75) M8010 2204EN