Search

Abstract: With attractive advantages of high efficiency, energy saving and environmental friendliness, the ground source heat pump (GSHP) system has been used widely in China in recent years. This paper summarizes the analytical solution, numerical solution and experimental investigation of the heat transfer of the ground heat exchanger (GHE), analyzes the simulation model and long-term operation performance of the GSHP system, and introduces the lastest hybrid ground source heat pump (HGSHP) system. In addition, this paper discusses and summarizes the shortages and imperfects of the current research on the simulation of the GSHP system and gives some recommendations for future work. [Copyright &y& Elsevier]

The equation describing the transfer of radiant energy in semitransparent media is radiative transfer equation. In three-dimensional semitransparent media, radiative intensity is a function of 7 dimensions, which can only be solved through the numerical method in most circumstances. Numerical simulation has become an important way in the study and application of the theory of thermal radiative transfer in semitransparent media. This paper reviews the recent progress of Chinese scholars in the field of computational thermal radiative transfer, and proposes some important subjects in this field for future study. [ABSTRACT FROM AUTHOR]

Abstract: This paper develops an overall methodology for investigating the thermal and power behaviors of semi-transparent single-glazed photovoltaic window for office buildings in Hong Kong. In order to estimate its overall energy performance, this study is conducted in terms of total heat gain, output power and daylight illuminance. Three simulation models are established, including one-dimensional transient heat transfer model, power generation model and indoor daylight illuminance model. A typical office room reference is chosen as case study, and the weather data from 2003 to 2007 from the Hong Kong Observatory are used as the simulation inputs. By incorporating the simulation results, the overall energy performance can be evaluated in terms of electricity benefits corresponding to five orientations of the studied typical office. The priority of office orientation considering overall energy performance is: south-east, south, east, south-west and west. The findings show that thermal performance is the primary consideration of energy saving in the entire system whereas electricity consumption of artificial lighting is the secondary one. The overall annual electricity benefits are about 900 kWh and 1300 kWh for water-cooled and air-cooled air-conditioning systems respectively. The application of semi-transparent PV glazed window can not only produce clean energy, but also reduce building energy use by reducing the cooling load and electrical lighting requirements, which definitely benefits our environmental and economic aspects. [Copyright &y& Elsevier]

In the Mogao Grottoes in Dunhuang, China, temperature and relative humidity (RH) fluctuations are the main causes of the observed deterioration. In this paper, we experimentally and numerically analyze hygrothermal transfer in the cave wall of the Mogao Grottoes. A coupled heat and moisture transfer 1D model is developed to simulate the hygrothermal behavior of the cave wall of the Mogao Grottoes, which adopts the temperature and water vapor pressure as driving potentials. The model is implemented in a programming. By constructing the numerical model of the wall under boundary conditions and comparing the measured data and simulation results, we validate the numerical model and analyze the hygrothermal transfer characteristics of the wall. The temperature and moisture profiles of the cave wall are experimentally measured and numerically determined. The simulation results are compared to experimental temperature and RH values, with good agreement despite the simplifying hypotheses adopted during modeling. By analyzing the heat and moisture distributions, we find that the heat and moisture transfer process in the cave wall changes in space and time. The complicated heat and moisture transfer directions vary cyclically. Additionally, moisture transfer in the cave wall reaches the steady state more rapidly than heat transfer. Hygrothermal cycling plays an essential role in the development of mural deterioration. The developed model provides theoretical support and a scientific method for the conservation of cave sites and a quantitative analysis approach to study mural relics. • Apply multidisciplinary method to studying mural disease in historical heritage. • Set up a hygrothermal transfer model for the cave walls, and evaluate the results. • Analyze the heat and moisture transfer properties in cave walls experimentally and numerically. • Provide a salt damage mechanism on murals relating to heat and moisture. [ABSTRACT FROM AUTHOR]