Service Instructions; The Heat Pump; Principles Of Function; Components - Danfoss DHP-H Installation And Service Instructions Manual

Service instructions

11 The heat pump
11 .1 Principles of function
A heat pump utilises the energy found in a natural heat source. Simply put, it obtains energy in the form of heat from a heat source. The
heat pump is, therefore, a very environmentally friendly and economical way of heating a house.
The heat pump has three separate fluid circuits
• Heat transfer fluid circuit – is the circuit that contains the water that transports the heat/energy to the heating system and the water
heater.
• Refrigerant circuit – is the circuit that contains a chlorine and freon free refrigerant that inside the heat pump, transfers the energy
retrieved from the brine circuit through evaporation, compression and condensation, and supplies it to the heat transfer fluid circuit.
• Brine circuit – is the circuit that contains an antifreeze water based mix that obtains and transports energy from the heat source to the
heat pump. This circuit is also known as the collector.
1 A fluid (brine) filled hose is lowered into a lake, buried in the ground or lowered into bedrock. The brine obtains energy from the heat
source by the fluid temperature in the hose being heated a few degrees by the surrounding heat source. The fluid filled hose is also
known as a collector.
2 The brine is guided into the heat pump's evaporator. The enclosed refrigerant in the refrigerant circuit is forced to boil as the pressure
in the expansion valve drops and later evaporates to a gas in the evaporator. The energy produced during this process is released by
the slightly heated brine.
3 The refrigerant that now contains a large quantity of energy in the form of heat is transferred to the compressor, which both increases
its temperature and pressure.
4 The refrigerant then continues to the condenser. When condensing, the refrigerant supplies its heat energy to the heat transfer fluid
circuit. The refrigerant's temperature decreases and returns to a liquid state.
5 The heat transfer fluid circuit transports the heat energy out to the water heater, radiator and the under floor heating system, which
heat up.
6 The refrigerant is then transported through the expansion valve where the pressure drops and the refrigerant starts to boil and then
the process starts again.
11 .2

Components

The heat pump is a complete heat pump installation for heating and hot water. It has the market's first compressor developed solely for
heat pumps. It has an integrated 180 litre water heater and auxiliary heating. TWS stands for Tap Water Stratificator. This technology results
in more effective heat transfer and more effective layering of the water in the water heater.
The heat pump is equipped with control equipment, which is controlled via a control panel.
Heat enters the house via a water borne heating system, a low temperature system. The heat pump supplies as much of the heat demand
as possible before auxiliary heating is engaged and assists.
The heat pump unit consists of five basic units:
1 Heat pump unit
• Scroll compressor
• Stainless steel heat exchanger
2
Condenser
Expansion valve/
pressure drop
Enclosed
refrigerant
Evaporator
Figure 51: Function principles of a heat pump .
Compressor/
pressure increasing
Brine
VMBMA102
Heat transfer fluid
circuit
Refrigerant circuit
Brine circuit