Model Analysis of Solar Thermal System with the Effect of Dust Deposition on the Collectors

In this study, a TraNsient SYStems (TRNSYS) simulation model for solar thermal systems is developed to assess the potential of solar energy utilization in cold climate zones, such as Ulaanbaatar (Mongolia), which is one of the five cities with the worst air quality in the world. Since air pollution contaminates solar collectors and decreases their efficiency, this model accounts for dust deposition behavior so that the best cleaning time for the collectors can be estimated. The simulation results show that the best cleaning time falls between the middle of January and the beginning of February. In addition, a collector cleaned once during the heating period is estimated to produce 12% more energy compared with a collector that has not been cleaned

モンゴルニオケルタイヨウネツシステムノセイノウヨソクトカイゼンニカンスルケンキュウ

博士（工学）東京農工大

Modeling and cleaning of dust deposition on glass tube of evacuated solar thermal collectors

In this paper, dust deposition of an evacuated tube solar thermal collector is modeled using measurement results of transmittance of the glass tubes that were exposed for long period under real environmental condition of Ulaanbaatar city and evironmental data measured during the exposure such as wind speed and direction, the amount of airborne dust PM10, and the amount of rain and snow. In addition, by the derived model, daily behavior of transmittance of the galss tubes is calculated and the daily change in transmittance is simulated in case that hand cleaning has been done during over-contamination. The purpose of this study is: with the assistance of the dust deposition model, appropriate cleaning time will be estimated with respect to thermal output of the solar thermal collector

A Solar Thermal Application for Mongolian Detached Houses: An Energy, Environmental, and Economic Analysis Based on Dynamic Simulations

Ulaanbaatar (Mongolia) is the coldest capital city in the world with approximately 98% of its heating demand satisfied by means of coal-burning stoves. This leads to enormous air pollutant emissions, with Ulaanbaatar being one of the top five most polluted cities in the world. In this study, an innovative solar hybrid heating system for the Mongolian scenario was used, which was based on the operation of a solar field composed of four series-connected evacuated tube heat pipe collectors, coupled with a thermal energy storage. The solar hybrid heating system was simulated and analyzed using the software TRNSYS. The simulations were designed to satisfy the heating demand of a typical single-family detached house located in Ulaanbaatar and were carried out with and without considering the soiling effects on the solar system operation. The overall performance of the proposed plant was compared with those associated with different fossil fuel-based Mongolian conventional heating systems, in order to assess the potential energy, environmental and economic benefits. The results highlighted that the proposed plant allowed for the obtainment of significant reductions in terms of primary energy consumption (up to 34.6%), global CO2 equivalent emissions (up to 52.3%), and operating costs (up to 49.6%), even if the expected return on the investment could be unacceptable

Performance of solar collectors under Mongolian climatic conditions: comparison between experimental and preliminary simulation results

In this paper the experimental performance of a solar circuit composed of four series-connected evacuated tubes solar collectors operating under the climatic conditions of Ulaanbaatar (Mongolia) during October 2015 and April 2016 are presented and discussed in detail. The measured data are analyzed in terms of recovered thermal energy as well as thermal efficiency in order to assess the potential of solar energy exploitation under harsh cold conditions. The measurements are also compared against the results of a simulation model developed by using the dynamic simulation software TRNSYS with the main aim of assessing its feasibility in accurately predicting the experimental values. A percentage difference between simulated and measured daily efficiency in the range from -5.8% and 11.7%, allowing to conclude that the model is able to simulate the thermal behaviour of the solar collectors and, therefore, it can be used to assess the applicability of the solar thermal system under different operating conditions and scenarios

Model analysis of solar thermal system with the effect of dust deposition on the collectors

In this study, a TraNsient SYStems (TRNSYS) simulation model for solar thermal systems is developed to assess the potential of solar energy utilization in cold climate zones, such as Ulaanbaatar (Mongolia), which is one of the five cities with the worst air quality in the world. Since air pollution contaminates solar collectors and decreases their efficiency, this model accounts for dust deposition behavior so that the best cleaning time for the collectors can be estimated. The simulation results show that the best cleaning time falls between the middle of January and the beginning of February. In addition, a collector cleaned once during the heating period is estimated to produce 12% more energy compared with a collector that has not been cleaned