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The thermal performance of solar cells plays an important role in the energy use of solar photovoltaic power generation. The surface temperature of solar cells is a key factor affecting the power generation efficiency. The use of phase change materials in solar cells can increase the thermal storage capacity and weaken the temperature fluctuation under the action of solar radiation, achieving the purpose of improving the system power generation performance. The aim of this paper is to investigate the phase change materials and their thermal performance for solar cell modules through simulations and experiments. In the experimental study, six types of binary composite phase change materials were prepared by selecting two of lauric acid, stearic acid, palmitic acid and tetradecanol in a 1:1 ratio. In the thermal performance tests of the phase change materials, the phase change temperature and latent heat of phase change were measured by the thermogravimetric method using a TGA/DSC simultaneous thermal analyser, and the thermal conductivity was measured by the probe method using a thermal conductivity meter. In the simulation study, a numerical model of the phase change heat transfer is developed, coupling the phase change material to the cell components and performing heat transfer analysis. The results are helpful to the selection of phase change materials that are beneficial for reducing the temperature of solar photovoltaic panels and to explore the effect of radiation levels on the materials.

The purpose of this study is to evaluate the effect of air curtains on indoor environment and dehumidification energy consumption for different air supply angle and velocity. The numerical investigation was conducted in a low-humidity plant located in the atmospheric boundary layer. The standard k-epsilon turbulence model was used in simulation study. The optimum air supply angle and velocity were evaluated based on temperature and humidity distribution. The simulation cases range in air supply angle from 0° to 20° and velocity from 6m/s to 14m/s, which were studied by means of orthogonal experiments. Simulation results show that air curtain can reduce the average indoor temperature of the plant by up to 3.9°C and reduce the average moisture content by up to 86.6% compared to the cases without air curtains. The energy saving assessment of the dehumidification rotor system shows a parabolic variation in energy consumption with increasing air velocity at a certain air supply angle. The optimum energy consumption occurs at the range of 9-11m/s for air supply velocity. When air supply velocity is over 11m/s, the airflow exchange is enhanced by air curtain at the plant opening, resulting the higher energy consumption from air leakage for dehumidification.

As a passive building energy-saving technology, shading systems are usually used to reduce the solar radiation into the unit and reduce the energy consumption of air conditioning system. For multi-storey buildings, shading devices can not only change the indoor thermal environment, but also change the indoor wind environment and air quality because their impact on airflow patterns of natural ventilation. In this paper, the numerical simulation method was used to investigate external shading louvers on the single-sided ventilation performance and indoor air quality of units at different positions in a multi-storey building. Three approaching airflow directions and three rotation angles of louvers were considered and analysed. The results show that the evaluation of ventilation performance of shading louvers in multi-storey buildings is important for shaded buildings, which provide a new perspective for the geometry design of shading louvers and ventilation design of buildings.

While development zones are the main locations of the urban industrial economy and sources of energy consumption, studies on the interactive relationship between mixed land use and CO2 emissions in these zones have not attracted much attention. In this paper, the development zone is selected as the research object, and a honeycomb grid with a side length of 50 meters is used as the unit to measure multiple dimensions of mixed land use. The efficiency and intensity of CO2 emissions are estimated for these units, and the coupling model is used to analyse the interactive relationship between these two factors. The results show that (1) the mixed land use degree of different types of development zones differs; the bonded zone has the highest degree, while the economic and technological development zone and the high-tech development zone have higher degrees than the industrial development zones. (2) The CO2 emissions capacities of economic and technological development zones and high-tech development zones are better than those of industrial development zones and bonded areas. (3) There is a strong interaction between the mixing degree of land use and the intensity of CO2 emissions; the relationship between the two may be diverse and complex in different development zones. (4) The coordinated development level between mixed land use and CO2 emissions in economic and technological development zones and bonded areas is better than that in high-tech development zones, which in turn is better than that in industrial development zones. Based on existing measurements of mixed land use, the index of land use intensity is introduced in this paper and the land use classification in development zones is refined to supplement the land use compatibility matrix. The results of this study have implications for the development zone to enhance mixed land use and low-carbon development. [ABSTRACT FROM AUTHOR]