The Heat Conversion group researches and further develops the field of heat conversion via chillers and heat pumps. Its range of research extends from the development and optimisation of individual components to their integration into complex energy systems. Many years of expertise have accumulated in the group, particularly on sorption heat pump and cooling systems (closed absorption, open adsorption), sorption storage systems, and innovative compression refrigeration applications.
The main work focuses are:
Head of Group:
Manuel Riepl, M.Sc
Tel.: +49 89 329442-43
Fax: +49 89 329442-12
Deputy Head of Group:
Andreas Krönauer, M.Eng.
Tel.: +49 89 329442-13
Fax: +49 89 329442-12
In the BioWap project, a functional model of a highly efficient absorption heat pump system fired directly with wood pellets at a heating capacity of about 90 kWth and a cooling capacity of up to 75 kWth was developed. The system efficiency is expected to reach up to 200 %.
The direct coupling of combustion and an absorption heat pump (working media: water and aqueous solution of lithium bromide) renders a low-temperature heat source usable. To keep the cost of planning and installation as low as possible, an integral hydraulic and control module was developed as well.
The project's core objective was to develop and illustrate a functional model of an absorption heat pump directly fired with wood pellets at a heating capacity of around 90 kWth (firing capacity around 50 kWth). This aimed to open up a new technological path for providing highly efficient low-emission heat. HDG Bavaria GmbH acted as the joint partner.
Head of Project: Manuel Kausche, M.Sc., email@example.com
Project Duration: 09/2016–08/2020
In project GALuWap, a compact, (bio)gas-fired absorption heat pump system for a maximum heating capacity of 50 kW is being developed. It uses outside air as a heat source and an environmentally neutral combination of water and an aqueous lithium bromide solution as a working medium.
Multi-stage absorption heat pumps can generate temperature lifts of up to 70 K, even using fairly cold outside air at a minimum temperature of -10 °C. They are therefore suitable to heat existing buildings and provide domestic hot water at up to 60 °C.
Thus, the typical demand for heat and domestic hot water in Germany can be almost completely covered through a heat pump. The seasonal thermal efficiency of the system reaches up to 1.3. So compared to gas condensing boilers, up to 25 % of the primary energy consumption may be cut. If cooling and heating are provided simultaneously, e.g. in mixed residential and commercial buildings, seasonal efficiency may increase to 1.6. Compared to a gas condensing boiler with compression chiller, this represents a reduction in consumption of up to 40 %.
To reduce cost and volume, plate heat exchangers developed in an earlier project are being examined to see if they can replace the shell-and-tube heat exchangers commonly used in heat pumps. Also, an integral hydraulic and control module is being developed to reduce the effort required for planning and installation. The greatest challenges lie in an operationally reliable implementation of the innovative cycle concept, including special precautions for operation below the freezing point of the water in use, as well as in the implementation of the gas-fired expulsion system.
Head of Project: Manuel Kausche, firstname.lastname@example.org
Project Duration: 12/2019–11/2022
Development of a highly efficient and economical trigeneration system for smaller outputs (approx. 20 kWel ) with highly efficient direct utilisation of the CHP's exhaust gas heat (450 °C) to drive a multi-stage absorption chiller and thus achieve a 25 % higher cooling yield than conventional cogeneration systems. The pre-assembled system with matched components cuts investment costs, making it economically attractive.
In the project, the integrated system is being designed and set up for extensive practical testing at the Kompetenzzentrum KWK in Amberg. At the component level, this involves the refinement of a high-temperature desorber with vertical boiling tubes, the development of a compact unit design for highly automated production, and matched components (CHP, multi-stage absorption chiller, hydraulics) as well as higher-level controls for the CHP system which interface with the building management system.
Head of Project: Christian Wuschig, email@example.com
Project Duration: 03/2017–05/2021
We conduct applied research at the interface between basic science and industrial application. Our methods and systems aim to achieve CO2 neutrality and thereby counteract climate change through the intelligent and efficient use of renewable energies.