The influence of using heat storage with PCM on inlet and outlet temperatures in substation in DHS

Abstract

Abstract:The main objective of this article is to indicate the direction of development of new generation heating systems that use phase change materials, and the important criteria needed when choosing a phase change material. The work contains a detailed classification of materials using the latent heat of organic and inorganic PCM. This references the technical possibilities of existing heat storage technologies. A specific objective was adopted to determine the effect of using heat storage with PCM on inlet and outlet temperatures in substation in district heating systems. The scope of the study included determining the parameters of the heat distribution network as a function of an outdoor air temperature within the range of -20°C to + 12°C. The object of analysis was chosen to be the heating system parameters: supply 120°C and return 60°C. It is located on the surface of 160km 2 , and supplies heat to 240,000 residents. The total length of the district heating network is 170 km. Based on the study, it was found that the most advantageous material that accumulates heat depends on the return temperature in the heating network. For the above analyzed case, the return temperature was in the range of 46°C to 57°C. The analysis showed that the most preferred materials using heat of phase change, have possible applications in heating networks and received a return temperature including salt hydrates, such as MgSO4·7H2O and Na2S2O3·5H2O. The introduction of stored heat for the district heating system with the phase change material in the form of salt hydrates, allows the return temperature in the district heating to remain at temperatures compatible with the adopted regulatory table for temperatures outside the standard heating season.

The use of substations with PCM heat accumulators in district heating system

“…Outside air temperature in the standard year reached the range of -2°C to + 5°C, then the return temperature of the heating network most often occur in the range from 47°C to 56°C. The phase change temperature of the PCM material should be predicted at this temperature, in accordance with previously performed tests described in publications [13,16].…”

“…In the literature of the subject of research, there are proposals for new technologies to increase the efficiency of the system, but these are mainly solutions within one efficiency, for example attempts to connect solar collectors to the grid [14,15] cogeneration [12,13] trigeneration [14] use pre-insulated wires [15,16] or the use of heat pumps [17]. At the moment, there are no comprehensive technological solutions that improve the overall efficiency of the entire system.…”

“…This situation is caused by insufficient knowledge in the use of heat accumulation technology using phase change [13]. Solutions with the use of phase change materials are most often present in the simulation or research phase [1,12].…”

Performance of the Heat Pump and Photovoltaic Systems Installed in the Single-family House

“…Using renewable energy sources in buildings can significantly help cover energy needs, which can also impact the air quality through proper ventilation. Heat accumulation can also be used (Nogaj et al 2017, Radek et al 2020, Turski & Jachura 2022 -possibly in combination with renewable energy sources -to enhance the energy performance potential further.…”

Life Cycle Assessment of Dispersed Phase Change Material Heat Accumulators for Cooperation with Buildings in the District Heating System

“…Therefore, there is a necessity for research and an urgent need to modernize the existing DHS in order to further develop and improve energy efficiency [13,14]. The solution that can solve these problems is modern heat storage technology-the utilization of dispersed PCM heat accumulators [15,16]. Currently, typical engineering solutions used to improve DHS efficiency within heating networks are lowering the temperature of the network water, using the technology of pre-insulated pipelines, and the replacement of group heating substations with individual ones equipped with regulation and automation.…”