Review of Large-Scale Heat Pumps and Potential of their Introduction to Natural Gas Markets

Heat pumps are gaining popularity all over the world. A lot of attention is paid to household and commercial use markets, as well as diverse small and medium scale industrial applications. On the other hand, large-scale customized heat pumps are still more an exception in energy industry than a common practice. This paper looks into existing large-scale heat pump installations in order to gain understanding of their integration acceptance. The investigation shows that a vast majority of large-scale heat pumps use electricity as input driving energy.In many areas of the world, electric energy is comparatively expensive and therefore heat pumps are not utilized to a great extent. However, by changing the input driving energy source, large-scale heat pump systems may find acceptance in new markets. In this paper, large-scale heat pump systems which use the mechanical energy output from a natural gas fired gas turbine as input driving energy source are investigated. The output heating energy from the heat pump is used to satisfy the heating energy requirement for a city using district heating. A simplified feasibility study shows that a large reduction in primary energy consumption can be achieved with such a system compared to production of heating energy by combustion of natural gas in a boiler