Evaluation on CO2 network for district heating and cooling system

Abstract

Reducing CO2 emissions by the effective use of renewable energy is one of the most important issues around the world. Therefore, many researchers have analyzed not only the development of individual high-performance equipment, but also the area-wide energy utilization systems. One of the area-wide energy utilization systems is a district heating and cooling system. However, conventional systems that utilize the steam and chilled water produced by the boiler and the chiller have some issues. Hence, the CO2 network system has been proposed by researchers in EPFL, Switzerland. The system uses the latent heat of CO2 refrigerant to transport and exchange unused heat to specific areas by employing decentralized heat pumps on demand-side. The proposed system is expected to significantly reduce energy consumption compared with the conventional system. In this paper, we analyzed the energy-saving effect by introducing the system to Japan based on CO2 emissions reduction in 2030. As a result, it was confirmed that the annual energy consumption and CO2 emissions resulting from equipment operation could be reduced by about 80% and 60% compared with the conventional system. By using the surplus electric power from renewable energy as the power supply source of the proposed system, it contributes to the construction of the optimal system for energy interchange.

Keywords

• district heating and cooling systems
• co2 emissions
• heat pump
• co2 refrigerant
• unused energy
• co2 networks
• urban energy systems