scholarly journals The effect of different types of window for residential building based on intermittent heating supply

2019 ◽  
Vol 136 ◽  
pp. 03020
Author(s):  
Chenyang Tao ◽  
Nan Li ◽  
Yuchen Wang
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Energy Consumption ◽  
Transfer Coefficient ◽  
Residential Buildings ◽  
Recovery Period ◽  
Residential Building ◽  
Thermal Design ◽  
Intermittent Heating ◽  
Different Types

Aiming to lessen energy consumption and heating cost, this paper analyzes the effect of different types of window for residential building based on intermittent heating supply. The research results show that the type of window with a smaller heat transfer coefficient has higher energy consumption. Otherwise, the rate of temperature rising is slightly affected by the change of window with different heat transfer coefficient and window-to-wall ratio. Based on the economic and technical analysis, through changing the better window, energy-saving ratio can be arrived to 10.4%-16.8% and economic recovery period is 4.4-10.4 years. The research findings can be used for reference to thermal design in new residential buildings and provide improvement of building performance for existing residential buildings.

scholarly journals Indoor environmental assessment method in residential kitchen

2020 ◽  
Vol 24 (3 Part B) ◽  
pp. 2055-2065
Author(s):  
Anita Vorosne-Leitner ◽  
Laszlo Kajtar ◽  
Jozsef Nyers
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Energy Consumption ◽  
Transfer Coefficient ◽  
Residential Buildings ◽  
Local Source ◽  
Radiant Heat Transfer ◽  
Main Role ◽  
Monitoring Method ◽  
Gas Stoves

Nowadays, energy consumption, environmental protection and safety are fundamental issues in design process. In order to reduce energy consumption, buildings become increasingly insulated and air tight. It has controversial effect on indoor environment, therefore, it has become essential to apply an effective ventilation system. This requires detailed design, especially if there is a strong, local source in the space. In residential buildings, gas stoves are significant source of gaseous pollutants and heat load. Indoor environmental assessments have been carried out in order to evaluate the key parameters. The aim of this studies is to develop a new design and monitoring method of residential kitchens with gas stoves. Primary results of laboratory researches indicate that the largest stovetop burner with power of 2.8 kW, has the main role. Significant emissions of NOx have been measured, in an average size kitchen (Vroom = 36 m3) the Hungarian standard NOx concentration level (200 ?g/m3) can be ensured with an exhaust air-flow of 1102 m3/h. With respect of thermal environmental parameters, heat loads of residential gas stoves could be characterized with convective heat transfer coefficient of 4.5 W/m2K and radiant heat transfer coefficient of 5.9 W/m2K. As regards thermal comfort parameters, predicted mean rate index in proved to be applicable in residential kitchens from ?0.3 to +2.0. However draught rating cannot be applied, with respect to the temperature limitations.

scholarly journals Research on Energy-Saving Design of Rural Building Wall in Qinba Mountains Based on Uniform Radiation Field

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Qin Zhao ◽  
Xiaona Fan ◽  
Qing Wang ◽  
Guochen Sang ◽  
Yiyun Zhu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Energy Consumption ◽  
Transfer Coefficient ◽  
Energy Saving ◽  
Radiation Field ◽  
Thermal Environment ◽  
Residential Buildings ◽  
South Wall ◽  
Heating Energy Consumption

How to create a healthy and comfortable indoor environment without causing a substantial increase in energy consumption has become a strategic problem that the development of all countries must face and solve. According to the climatic conditions of Qinba Mountains in China, combined with the characteristics of local rural residential buildings and residents’ living habits, the field survey and theoretical analysis were used to study the thermal environment status and the heating energy consumption condition of local rural residential buildings. The thermal design method of walls for the local rural energy-saving buildings based on the indoor uniform radiation field was explored by using the outdoor comprehensive temperature function expressed by the fourth-order harmonic Fourier series as the boundary condition of the wall thermal analysis. ANSYS CFX was adopted to study the suitability of the energy-saving wall structure designed by the above method. The results show that the indoor thermal environment of local rural residential buildings in winter is not ideal and the heating energy consumption is high, but this area has the geographical advantage to develop solar energy buildings. It is proposed that the indoor thermal comfort temperature of local rural residential buildings in winter should not be lower than 14°C. When the internal surface temperature of the external walls in different orientations are equally based on the design principle of uniform radiation field, the heat transfer coefficient of the east wall, the west wall, and the north wall of the local rural residential buildings is 1.13 times, 1.06 times, and 1.14 times of the south wall heat transfer coefficient, respectively. The energy-saving structural wall with KPI porous brick as the main material and the south wall heat transfer coefficient of 0.9 W/(m2·K) is the most suitable energy-saving wall for local rural residential buildings.

Determination of the Effect of Wall Heating Systems on Convective Heat Transfer Coefficient in Buildings

2014 ◽  
Vol 875-877 ◽  
pp. 1630-1636 ◽  
Author(s):  
Ozgen Acikgoz ◽  
Olcay Kincay ◽  
Zafer Utlu
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Heated Wall ◽  
Real Size

Decreasing energy consumption and advancing thermal comfort are the most important aims of building engineering. Previously reported studies by many researchers have found that different usages of convective heat transfer coefficient (CHTC) correlations in heating system simulations have considerable impacts on calculated heating load in buildings. Hence, correct utilization of CHTCs in real size room enclosures has great importance for both energy consumption and thermal comfort. In this study, a modeled room was numerically heated from one vertical wall and cooled from the opposite wall in order to create a real room simulation. While cooled wall simulate heat losses of the room, heated wall simulates the heat source of enclosure. Effects of heated and cooled wall temperatures and characteristic length on CHTC and Nusselt number in the enclosure were numerically investigated for two (2-D) and three dimensional (3-D) modeling states. CHTCs and Nusselt numbers of a real size room with the dimensions of 6.00 by 2.85 by 6.00 were found with FLUENT CFD and graphics of change were drawn. As result, difference between 2-D and 3-D solutions was found approximately 10%. This was attributed as the effect of air flow pattern effects over other surfaces in the enclosure that can not be counted at 2-D solutions. The change of CHTC at different characteristic lengths was illustrated as well.

The Optimization Ratio Study of Steady State Heat Transfer and Dynamic Heat Transfer in Hot-Humid and Cold-Humid Area

2014 ◽  
Vol 935 ◽  
pp. 52-56
Author(s):  
Shuang Liang ◽  
Wang Yan
Keyword(s):  
Heat Transfer ◽  
Thermal Stability ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Inertia ◽  
Residential Building ◽  
Optimal Matching ◽  
Shape Coefficient ◽  
Inertia Index ◽  
Matching Relation

By means of the establishment of thermal stability evaluation model and simulating in Huafeng factory residential building ,the relationship between the D value and building thermal stability and the optimal distribution ratio are obtained.The results show that:at the shape coefficient≤0.40, the most optimal matching relation is :heat transfer coefficient is 1.0, thermal inertia index is 2.0;at the shape coefficient >0.40, the most optimal matching relation is :heat transfer coefficient is 0.8, thermal inertia index is 2.0.

Generalization of the Heat Transfer Coefficient Concept for System Simulation

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Mohamed-Nabil Sabry
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Thermal Design ◽  
3D Simulation ◽  
Good Precision ◽  
Zeroth Order ◽  
3D Simulations ◽  
Transfer Problems ◽  
The Heat Transfer Coefficient

Large progress has been realized in modeling conduction heat transfer problems over the past decade by the introduction of high performance compact thermal models (CTMs) mainly developed for thermal design of complicated electronic systems. The objective of this paper is to generalize these advances to convective heat transfer. A new convective CTM is proposed, which offers many advantages over the traditional approach using the heat transfer coefficient (HTC). The latter is simply a zeroth order CTM. The HTC is quite handy and simple, but with unpredictable errors. It can be suitable for hand calculations of simple systems giving rather crude estimates. For a higher precision, users have no other option than time consuming 3D simulations. For large systems, in terms of number of components, 3D simulations can be rapidly impractical. The CTM bridges the gap between both approaches going gradually from “HTC” levels (low precision and calculations time) at the zeroth order, to 3D simulation precision and computing time levels at large orders. Fortunately, like for conduction, a CTM of order of few tens quickly approaches 3D simulation precision levels, while keeping computation time significantly lower than 3D simulation. Moreover, the CTM approach solves conjugate heat transfer problems in a quite elegant way. A “black box” model, developed for fluid domain alone, can be easily combined with classical CTM conduction models to generate good precision predictions for any combination of fluid/solid domains.

Thermal Performance Enhancement of an Industrial Shell and Tube Heat Exchanger

2015 ◽  
Author(s):  
Fadi A. Ghaith ◽  
Ahmed S. Izhar
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Transfer Coefficient ◽  
Thermal Performance ◽  
Numerical Study ◽  
Thermal Design ◽  
Shell Side ◽  
Tube Heat Exchanger ◽  
Shell And Tube

This paper aims to enhance the thermal performance of an industrial shell-and-tube heat exchanger utilized for the purpose of cooling raw natural gas by means of mixture of Sales gas. The main objective of this work is to provide an optimum and reliable thermal design of a single-shelled finned tubes heat exchanger to replace the existing two- shell and tube heat exchanger due to the space limitations in the plant. A comprehensive thermal model was developed using the effectiveness-NTU method. The shell-side and tube-side overall heat transfer coefficient were determined using Bell-Delaware method and Dittus-Boelter correlation, respectively. The obtained results showed that the required area to provide a thermal duty of 1.4 MW is about 1132 m2 with tube-side and shell-side heat transfer coefficients of 950 W/m2K and 495 W/m2K, respectively. In order to verify the obtained results generated from the mathematical model, a numerical study was carried out using HTRI software which showed a good match in terms of the heat transfer area and the tube-side heat transfer coefficient.

Numerical Simulation of a Canadian Well With Several Circumferential Rows of Internal Vortex Generators

2021 ◽  
Author(s):  
Nabil Kharoua ◽  
Hamza Semmari ◽  
Houssem Korichi ◽  
Mehdi Haroun
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Residential Buildings ◽  
Vortex Generators ◽  
Ambient Conditions ◽  
Operational Conditions ◽  
Positive Effects ◽  
The Heat Transfer Coefficient

Abstract Canadian Wells exploit the quasi-stable underground temperature throughout the year for cooling and heating applications. This type of heat exchangers is used in residential buildings, agriculture and industry. Implementing Vortex Generators (VGs) is intended to disturb the thermal and dynamic boundary layers developing in the near-wall regions leading to the increase of the heat transfer coefficient. The present work investigates the positive effects of a sequence of several rows of VGs. The commercial code ANSYS FLUENT was used to perform numerical simulations mimicking the variation of the seasonal operational conditions occurring within one year. The ambient conditions were considered for the city of Constantine located in the east of Algeria at an altitude of 600m over the sea level. Sinusoidal functions of time and depth, were used for the yearly variations of the ground and air temperatures. Parallelepiped VGs were considered in this study. The Reynolds number was in the range Re = 14975–42789. The results illustrated a contrasting effect of the Reynolds number on the heat transfer coefficient and the temperature difference between the inlet and outlet of the Canadian Well. In terms of number of VGs rows, the beneficial heat transfer effects were observed till the fifth row only.

Energy-Saving Test and Analysis of a Steel Residential Building in Cold Regions of China

2011 ◽  
Vol 243-249 ◽  
pp. 6938-6941
Author(s):  
Xiao Tong Peng ◽  
Chen Lin
Keyword(s):  
Energy Consumption ◽  
Energy Dissipation ◽  
Energy Saving ◽  
Residential Buildings ◽  
Residential Building ◽  
Building Envelope ◽  
Thermal Design ◽  
Actual Energy Consumption ◽  
Site Test ◽  
Heat Bridge

An on-site test on envelope of a typical steel residential building in cold region is performed. The testing results provide evaluation bases for the energy-saving effects of the steel residential building. In order to evaluate the main factors that influence energy dissipation of the building and estimate the main energy dissipation positions, the heat transfer coefficient K of envelope and its actual energy consumption are calculated based on the testing data. The results indicate that the building envelope has good heat storage property and it could keep indoor thermal stability; the steel frames and windows have heat bridge effects. Through calculations of the energy consumption of envelope, it is showed that the tested building only meet the requirement of energy saving by 50%, instead of 65%; the external walls and windows are main energy dissipation parts. Finally the thermal design recommendations about steel residential buildings are proposed.

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