Investigation of energy performance and operational schemes of a Tibet-focused PCM-integrated solar heating system employing a dynamic energy simulation model.

Abstract Integration of a latent heat energy storage into a solar heating system has become a well-known engineering practice that can bridge the mismatch between the heat demand of the served building and heat supply from the solar heating system. However, control schemes, energy performance analysis, characterization and optimization of such a system under the Tibet climatic/altitude conditions still remain a challenge. This research aims to investigate a PCM-integrated solar heating system applicable to Tibet which is unique in terms of the altitude, solar radiation, atmospheric pressure and water boiling temperature etc. The whole process involves (1) identification of the unique features of Tibet climate and altitude and relevant requirements to the solar system; (2) design of a PCM-integrated solar heating system based on a selected building in Lhasa and planning the potential control strategies appropriate to such a system; (3) analysis of the system's energy performance under different operational schemes; and (4) recommendation of the most appropriate system operational scheme and design strategy. A dynamic simulation model was established and applied to study the energy performance of such a system, in which the solar energy usage rate is defined as the performance evaluation index. It is found that the operational scheme 'A' has the best energy saving effect, followed by operational schemes B and C. The system presents a more favorite energy performance between 9:00 h–18:00 h, compared to other time slots in a typical winter day. Change in operational schemes creates a significant impact on the energy saving effect of the system. The results help wide and fast deployment of the PCM-integrated solar heating system and enable the determination of the best performing operational scheme and associated performance data appropriate to Tibet or similar regions in the world, thus making a significant contribution to the saving of fossil fuel energy consumption and reduction of the carbon emission on the regional and global scales. Highlights • Energy performance and operational schemes of a Tibet-focus SHS-PCM was investigated. • Operational scheme A is the best and C is the worst in terms of energy saving rate. • Daytime heating achieved a higher energy efficiency compared to the full day heating. • Energy saving rates for three schemes are 64%, 50% and 46% for the full day heating. • Energy saving rates for three schemes are 92%, 79% and 24% for daytime heating. [ABSTRACT FROM AUTHOR]