Groundwater Heat Pump Simulation with Polysun

Groundwater is a reliable, efficient thermal energy source for heat pumps, offering consistent temperatures year-round for stable heating performance. With Groundwater Heat Pump Simulation, Polysun delivers precise modeling, optimizing thermal and hydraulic design for cost-effective, high-efficiency systems.

Temperature calculation depending on depth

The temperature is calculated depending on depth. The following assumptions were made in this respect:

Soil temperature θ(x,t) depending on depth x (into the soil) and time t varies under the influence of the seasonal course of the outdoor temperature according to the following formula:

\(\theta(x,t) = \ \theta_{m} – \ \theta_{0} \cdot exp\left( – x\sqrt{\frac{\pi}{a \cdot T}} \right) \cdot cos\left( \frac{2\pi}{T}t – x \cdot \sqrt{\frac{\pi}{a \cdot T}} \right)\)

Constant groundwater temperature from a depth of 10-15 metres

With a ground water depth of about 10-15 m and deeper it can be assumed with good accuracy that the ground water temperature remains constant over the year and  matches the average annual outdoor temperature.

Static Pressure

Polysun enables users to correctly calculate both static and dynamic pressure. To correctly calculate the required height difference ∆H a distinction should be made whether or not the loop return line is immersed in the return water tank.  A negative difference is also possible; this will result in the pump being relieved of pressure. The image below illustrates this correlation: