Integration of libr/H2O absorption heat pump and absorption heat transformer in total site heat integration

Energy efficiency is one of the main solutions to reduce CO2 emissions in the energy sector and improve primary energy intensity. Energy savings are at the centre of the numerous advantages of energy efficiency and connect to many other economic, social and environmental advantages. Total Site Heat Integration (TSHI) was introduced to maximise the heat recovery from various processes through a centralized utility system. Heat pump using absorption cycle has been identified as one of the waste heat recovery techniques. The challenges of heat pumps applications include limited temperature applications and long payback periods. However, these problems can be tackled by proper design and suitable types of heat pumps considerations. This paper integrates two different kinds of absorption cycle heat pump which are absorption heat pump (AHP) and absorption heat transformer (AHT) into the context of TSHI. This integration is able to reduce the industrial waste heat and generate quality steam. The heat generation of AHP and AHT are estimated based on the enthalpy of working fluid pair of water-lithium bromide. A case study is done to compare and verify the proposed methodology. Economic analysis is performed to compare the different integration approaches of AHP and AHT. Results showed that the integration of hybrid AHP and AHT contribute to the highest annual saving (21,351 USD/y) of utility cost compared to 12,356 USD/y for AHP system and 9,119 USD/y for AHT system