Effects of Coupling Combined Heat and Power Production with District Cooling

Abstract

Over the past decades, combined heat and power production (CHP) has proven itself to be an efficient means of meeting both heat and power demands. However, high efficiency can be achieved with CHP plants when the heat load is sufficient, while lower-priority CHP plants must deal with the excess heat associated with power generation. This excess heat can be used for district cooling with absorption chillers. Although the absorption chiller is an efficient technology for using excess heat for cooling generation, its efficiency is very sensitive to driving hot water temperature. This paper provides a detailed analysis of how cooling generation in CHP plants using absorption chillers affects power generation and primary energy consumption. This study is based on the operational parameters of the Mustamäe CHP plant (Tallinn, Estonia) and the cooling demand of the Tehnopol science and business campus and proposes a sufficient cooling production capacity based on the estimation of the campus’ cooling demand. Additional cooling production opportunities to meet district cooling demand are discussed and compared in this paper in terms of primary energy savings and economic profit. The study finds that for the effective use of CHP excess heat and efficient cooling production, the use of an 0.8 MW absorption cooler and 11.6 MW heat pumps is recommended. This system would use 1.9 times less primary energy for cooling generation than local cooling.

Methodology for Modernizing Local Gas-Fired District Heating Systems into a Central District Heating System Using Gas-Fired Cogeneration Engines—A Case Study

“…According to the authors of the cited work, such a system has a chance to achieve net-zero CO 2 emissions. This is confirmed by the results of the analysis carried out in [49] for the technology campus in Tallinn (Estonia). It has been shown that the use of system cooling can result in "1.9 times less primary energy for cooling generation than local cooling".…”

Reducing CO2 Emissions for PV-CHP Hybrid Systems by Using a Hierarchical Control Algorithm

“…In recent studies, combined heat and power (CHP) systems have been increasingly investigated in the context of district heating and in combination with other energy systems. One such study, conducted by the authors of [18], provides a comprehensive analysis of the impact of cooling generation in CHP plants using absorption chillers on power generation and primary energy consumption. The research findings suggest that to effectively utilize excess heat from CHP systems and achieve efficient cooling production, the recommended configuration includes an 0.8 MW absorption cooler and 11.6 MW heat pumps.…”