18 May 2017

O.3.8.3 Application of an industrial heat pump for steam generation using district heating as a heat source

Many industries have heat demands at temperatures above 100°C and very often the preferred energy carrier is steam. District heating companies are looking for industrial customers that has a steady demand of heat, but are often unable to supply the heat at the necessary temperature. In this paper we present a high temperature heat pump and auxiliary equipment capable of generating up to 10 barg (184°C) steam from district heating. The paper expands on the previous work by the author presented at the 11th IEA Heat Pump Conference in Montréal, Canada in 2014. In the previous work the performance of a commercial installation of the heat pump that generated 110°C hot water from waste heat was presented. In this paper we present the technology, the general performance, and a case study for steam generation at 184°C using district heating as a heat source.
The case study is at a dairy plant, where the heat source is district heating at 80-85°C. The steam at 10 barg is generated by circulating water over the internal heat exchangers and in a steam generator. The dairy plant benefits by significantly reducing their carbon emission, as the steam generated by the heat pump replaces steam generated by natural gas. District heating company gets a steadier short and long term heat demand, and subsequently a better utilisation of their power plant and district heating network.