Solmodul jord- och bergvärmepump
An increasing number of heat pump producers have developed heat pumps that can be connected to solar panels. In this thesis we have examined the possibilities of connecting solar panels to existing ground source- and geothermal heat pumps that has not been adapted to solar panels. During the work process, a prototype plant has been built to compare our theory with the practical results and with our designed sizing tool. The work has rendered in knowledge that will be used to build a sun module that can be easily connect to the existing heat pump system. The existing heat pump, our test plant, has been supplemented by an advanced storage tank used to allow different operating modes. When there is an excess of solar energy from the solar collectors the borehole should be recharged and be stored in the ground for a shorter period of time. The heat pump refrigerants should also be preheated in the storage tank where the heat from solar collectors is not sufficient to directly go to the heating or domestic hot water demand. These functions should make it possible to maximize the usage of the solar power in the system. The thesis has rendered in a design basis for our client, on how a solar module best should be connected to the existing heat pump system. The conclusion is that there are difficulties in profitability and return on the investment cost of a sun module, because the pay-off time becomes unreasonably long. Several features such as preheating the brine circuit are not economically justifiable when the investment cost is too high in relation to the energy gain. The benefits are increased efficiency at both the solar collectors and the heat pump, along with the potential for a longer life for the heat pump.