Experimental and analytic study of a hybrid solar/biomass rural heating system

• Published in: Energy (Oxford) 2020-01, Vol.190, p.116392, Article 116392
• Main Authors: Zhang, Xinghui, Yang, Jiaojiao, Fan, Yi, Zhao, Xudong, Yan, Ruimiao, Zhao, Juan, Myers, Steve
• Format: Article
• Language: English
• Subjects: Algorithms; Arrays; Biomass; Biomass energy; Biomass energy production; Coal-fired power plants; Computer simulation; Control algorithms; Control theory; Efficiency; Energy; Energy consumption; Energy conversion; Energy conversion efficiency; Energy demand; Energy storage; Energy usage; EnergyPlus; Exergy; Exergy efficiency; Field tests; Heat exchange; Heat storage; Hybrid systems; Indoor environments; Micro-channel panel; Microchannels; Power efficiency; Power plants; Rural house; Solar energy; Solar heating; Solar panels; Space heating; Thermodynamic efficiency; Thermodynamics; Water tanks
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2019.116392

This paper presents a dedicated analytic and experimental study of a hybrid solar/biomass space heating system incorporating a micro-channel solar thermal panels-array, a biomass boiler and a dedicated control algorithm. This system enables the smart and joint use of solar and biomass energies to provide a comfortable indoor environment. The in-situ testing of the system was undertaken and the data obtained from the testing were analysed using Grubbs method to formulate the experimental thermal efficiency equation for the solar panels-array and the heat conversion factor equation for the combined heat storage/exchanging water tank. The annual energy performance of the hybrid system was investigated using a professional building energy simulation program (EnergyPlus), which can predict the heat load profile of house, the ratio of energy usage from solar/biomass sources and the primary energy/exergy efficiencies. The thermal efficiency of the solar thermal panels-array is in the range of 60%–70%. The heat storage water tank has a heat conversion factor in the range of 0.94–0.98. The heat load index per unit area is 46.86 W/m2 and cumulative heating energy consumption with 100 m2 house is 24.3 GJ during a heating season. The total annual energy demand of the solar/biomass heating system is around 35.91 GJ, of which the sun provides 63.31% and biomass provides 36.69%. The primary energy and exergy efficiencies of the solar/biomass rural heating system are 67.66% and 16.17% respectively. However, when the total input electrical exergy is traced back to its primary energy source, i.e. a coal-fired power plant, the exergy efficiency falls from 23.14% to 7.27%. Compared to the traditional primary energy supply system, the energy conversion effect and effective utilization degree of the solar/biomass heating system are relatively higher. •The simulation and actual operation of solar/biomass heating system was undertaken.•The thermal efficiency of solar thermal panels-array is around 65%.•Ratios of solar and biomass energy usage are 63.31% and 36.69% respectively.•The exergy efficiency of solar/biomass rural heating system is 16.17%.