Thermal performance of buildings. Transmission heat loss coefficient. Calculation method

2015 ◽  
Keyword(s):  
Heat Loss ◽  
Thermal Performance ◽  
Calculation Method ◽  
Loss Coefficient

Cavity receiver thermal performance analysis based on total heat loss coefficient and efficiency factor

2018 ◽  
Vol 42 (6) ◽  
pp. 2284-2289 ◽  
Author(s):  
Qiangqiang Zhang ◽  
Xin Li ◽  
Zhifeng Wang ◽  
Zhi Li ◽  
Hong Liu ◽  
...  
Keyword(s):  
Performance Analysis ◽  
Heat Loss ◽  
Thermal Performance ◽  
Efficiency Factor ◽  
Loss Coefficient ◽  
Total Heat ◽  
Total Heat Loss

Experimental investigation of the comparison of compound parabolic concentrator and ordinary heat pipe-type solar concentrator

2018 ◽  
Vol 29 (5) ◽  
pp. 770-783
Author(s):  
Fahim Ullah ◽  
Mansoor K Khattak ◽  
Kang Min
Keyword(s):  
Flat Plate ◽  
Heat Pipe ◽  
Heat Loss ◽  
Thermal Performance ◽  
Performance Comparison ◽  
Loss Coefficient ◽  
Fluid Temperature ◽  
Solar Concentrator ◽  
Average Heat ◽  
Compound Parabolic Concentrator

In this research study, we have compared between the two different concentrators with the flat absorber plate receiver of the compound parabolic concentrator heat pipe solar concentrator and ordinary heat pipe flat plate solar concentrator. For the reproduction of solar radiation in the experiment, iodine tungsten lamp was used. Thermal performance comparison of the two types of solar concentrator under different simulating radiation intensity conditions was carried out with including the fluid temperature, instantaneous efficiency, average efficiency, and average heat loss coefficient. The results of the experiment indicate that the compound parabolic concentrator heat pipe-type solar concentrator not only increased the fluid temperature and instantaneous efficiency but also decreased the average heat loss coefficient as compared with the ordinary heat pipe flat plate solar concentrator. It was noticed from the experimental results that the efficiency of compound parabolic heat pipe solar concentrator was higher than ordinary heat pipe solar concentrator up to 6 and 10°C with the light intensity, that is I = 679 W/m2 and I = 892 W/m2, respectively. From the results, it was concluded that the using of compound parabolic heat pipe solar concentrator increased the thermal performance of solar concentrator.

scholarly journals Study on the Variable-Temperature Drying Process of Corn Drying in an Industrial Corn-Drying System Equipped with a Self-Adaptive Control Heat Exchanger

2021 ◽  
Vol 11 (6) ◽  
pp. 2772
Author(s):  
Bin Li ◽  
Zhiheng Zeng ◽  
Xuefeng Zhang ◽  
Ye Zhang
Keyword(s):  
Adaptive Control ◽  
Energy Consumption ◽  
Heat Loss ◽  
Thermal Performance ◽  
Variable Temperature ◽  
The Other ◽  
Drying Process ◽  
Drying Kinetic ◽  
Drying System ◽  
Self Adaptive

To realize energy-saving and efficient industrial grain drying, the present work studied the variable-temperature drying process of corn drying in a novel industrial corn-drying system with a heat recycling and self-adaptive control function. The drying kinetics, thermal performance, heat-loss characteristics and the heat-recycling performance of the drying system under different allocations between flue gas and hot air were investigated, and the optimized drying process was proposed and compared with two constant drying processes. The results showed that the optimized drying process exhibited better drying kinetic and thermal performance than the two constant drying processes. More specifically, the total heat loss, total energy consumption and specific energy consumption of the optimized drying process were ascertained to be 36,132.85 MJ, 48,803.99 MJ and 7290.27 kJ/kg, respectively, which were lower than those of the other two processes. On the other hand, the thermal efficiency of the drying chamber for the optimized drying process was ascertained to be varied within the range of 6.81–41.71%. Overall, the validation results showed that the optimized drying process can significantly improve the drying performance of the drying system.

Research and Improvement on Calculation Method of Optimal Excess Air Ratio

2014 ◽  
Vol 536-537 ◽  
pp. 1583-1586
Author(s):  
Jun Xiong Qi
Keyword(s):  
Heat Loss ◽  
Correction Factor ◽  
Calculation Method ◽  
Traditional Method ◽  
Combustion Efficiency ◽  
Exhaust Gas ◽  
Incomplete Combustion ◽  
Excess Air

By analyzing the relations of the excess air ratio to heat loss due to exhaust gas, chemical incomplete combustion and combustibles in refuse, the traditional method for solving the optimal excess air ratio is improved. A correction factor is proposed for heat loss due to combustibles in refuse, making the solving method more accurate, which is of great importance for improving the combustion efficiency of the boiler.

Construction and Experimental Study of an Elevation Linear Fresnel Reflector

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
J. D. Nixon ◽  
P. A. Davies
Keyword(s):  
Heat Loss ◽  
Thermal Efficiency ◽  
Theoretical Models ◽  
Loss Coefficient ◽  
Heat Transfer Fluid ◽  
Stagnation Temperature ◽  
Model Predictions ◽  
The Difference ◽  
Predicted Values ◽  
Linear Fresnel Reflector

This paper outlines a novel elevation linear Fresnel reflector (ELFR) and presents and validates theoretical models defining its thermal performance. To validate the models, a series of experiments were carried out for receiver temperatures in the range of 30–100 °C to measure the heat loss coefficient, gain in heat transfer fluid (HTF) temperature, thermal efficiency, and stagnation temperature. The heat loss coefficient was underestimated due to the model exclusion of collector end heat losses. The measured HTF temperature gains were found to have a good correlation to the model predictions—less than a 5% difference. In comparison to model predictions for the thermal efficiency and stagnation temperature, measured values had a difference of −39% to +31% and 22–38%, respectively. The difference between the measured and predicted values was attributed to the low-temperature region for the experiments. It was concluded that the theoretical models are suitable for examining linear Fresnel reflector (LFR) systems and can be adopted by other researchers.

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