Estimation of waste heat potential for application in high temperature heat pumps in Finland

Abstract

This research thesis is centered on the exploration of the technical potential of industrial waste heat recovery in Finland, with a unique focus on quantifying the amount of recoverable and utilizable waste heat for which a novel strategy based on waste heat fractions was developed. This concept was derived from an extensive study of the UK industry from 2000 to 2003. The fractions denote the percentage of heat consumption that is initially lost but can be potentially regained. The study involves identifying different levels of waste heat across major industry sectors in Finland and defining the temperature ranges suitable for the application of heat pumps. This is achieved by comparing waste heat fractions from the UK's industrial sectors between 2000 and 2003 with those in Finland during the same period. The goal of this comparison is to highlight the differences in energy efficiency between the two countries. To ensure accuracy and relevance, the waste heat fractions for the most recent year were adjusted according to changes in Finland's overall energy intensity and individual industrial sector values between 2000 and 2003. This led to the creation of updated fractions per temperature level and industry. The primary outcome of the research is an exhaustive breakdown of the waste heat potential within major industrial sectors in Finland, categorized by the amount of waste heat produced across various temperature ranges. This data can be used to estimate the potential for heat recovery in each sector. The study acknowledges the role of heat pumps in capturing waste heat energy, specifically below 100 degrees Celsius and between 100 and 200 degrees Celsius. Despite the presence of energy recovery mechanisms, a significant proportion of thermal energy remains unrecovered. This research also underscores the importance of low-temperature waste heat (LTWH) recovery, frequently used in a variety of industrial and domestic applications, as a means to reduce greenhouse gas emissions. The study's key findings include the calculation of Finland's total waste heat potential below 200 °C, estimated at approximately 15 PJ, based on the average value over the past eleven years. It also quantifies the potential cost savings and emission reductions that could be achieved through the utilization of waste heat. The findings of this study can be employed to evaluate the feasibility of heat recovery initiatives using heat pumps.