scholarly journals Development of A Process for Predicting the Overall Heat Transfer Coefficient for Transient Heat Transfer in An Exhaust System using CFD

2019 ◽  
Vol 8 (2) ◽  
pp. 2529-2533
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Analytical Solution ◽  
Transfer Coefficient ◽  
Gas Flow ◽  
Transient Flow ◽  
Exhaust System ◽  
Outlet Temperature ◽  
Governing Equations ◽  
Overall Heat Transfer Coefficient

The analysis of heat transfer of automotive exhaust system is most important since their prominence in the design and also in the optimization phase of exhaust after treatment system.This paperdeals with the process which can be useful to predict the overall heat transfer coefficient for the transient flow of pipe in the after treatment system. This considers the convection of heat along gas flow, the convection between gas and wall, conduction through wall, radiation and of course convection to the ambient. Governing equations are obtained for the transient flow in a pipe for calculating gas temperature and wall temperature at distance x and time t. Analytical solution will be computed using CFD techniques for these governing equations. From the obtained analytical solution to the transient flow in pipe an excel tool will be developed which can be able to give the outlet temperature of the pipe in transient flow at length x and time t, total heat loss from pipe to the ambient, overall heat transfer coefficient for the pipe

Evaluating the Effective Friction Factor and Overall Heat Transfer Coefficient During Unsteady Pipeline Operation

1999 ◽  
Vol 121 (2) ◽  
pp. 131-136 ◽  
Author(s):  
G. R. Price ◽  
R. K. McBrien ◽  
S. N. Rizopoulos ◽  
H. Golshan
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Flow Model ◽  
Transient Flow ◽  
Time Varying ◽  
Flow Conditions ◽  
Outlet Pressure ◽  
Overall Heat Transfer Coefficient

This paper presents a method to determine the effective friction factor and overall heat transfer coefficient for a high-pressure, natural gas pipeline during fully transient flow conditions. Time-varying SCADA (supervisory control and data acquisition) measurements at the pipeline boundaries (i.e., inlet and outlet) provide boundary conditions for a transient flow model, as well as additional information which is utilized to determine these parameters. The resulting friction factor and overall heat transfer coefficient minimize the least-squared difference between the additional SCADA measurements at the pipeline outlet and the corresponding values predicted from the transient flow model. This concept is referred to as parameter estimation. The transient flow model is based on a numerical solution of the one-dimensional conservation equations (i.e., continuity, momentum, and energy) which are discretized using a highly accurate compact finite-difference scheme. The transient flow model and parameter estimation is incorporated into a computer program that is initially tested on a simple pipeline with steady flow conditions. The predicted outlet pressure and temperature using the estimated friction factor and overall heat transfer coefficient exactly matches the corresponding prescribed values. Subsequently, a portion of the Foothills Pipe Line Ltd. transmission system in Alberta is considered using time-varying SCADA flow measurements. The resulting outlet pressure and temperature from the transient flow model are in good agreement with SCADA measurements for this pipeline section.

Evaluating the Effective Friction Factor and Overall Heat Transfer Coefficient During Unsteady Pipeline Operation

1996 ◽  
Author(s):  
Glenn R. Price ◽  
Robert K. McBrien ◽  
Sandy N. Rizopoulos ◽  
Hossein Golshan
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Flow Model ◽  
Transient Flow ◽  
Time Varying ◽  
Flow Conditions ◽  
Outlet Pressure ◽  
Overall Heat Transfer Coefficient

This paper presents a method to determine the effective friction factor and overall heat transfer coefficient for a high pressure, natural gas pipeline during fully transient flow conditions. Time varying SCADA (Supervisory Control And Data Acquisition) measurements at the pipeline boundaries (i.e., inlet and outlet) provide boundary conditions for a transient flow model as well as additional information that is utilized to determine these parameters. The resulting friction factor and overall heat transfer coefficient minimize the least-squared difference between the additional SCADA measurements at the pipeline outlet and the corresponding values predicted from the transient flow model. This concept is referred to as parameter estimation. The transient flow model is based on a numerical solution of the one-dimensional, unsteady flow equations (i.e., continuity, momentum and energy) which are discretized using a highly accurate compact finite-difference scheme. The transient flow model and parameter estimation are incorporated into a computer program that is initially tested on a simple pipeline with steady flow conditions. Here, the predicted outlet pressure and temperature, using the estimated friction factor and overall heat transfer coefficient, exactly matches the corresponding prescribed values. Subsequently, a portion of the Foothills Pipe Line Ltd. transmission system in Alberta is considered using time varying SCADA flow measurements. The resulting outlet pressure and temperature from the transient flow model are in good agreement with SCADA measurements at this location.

Application of Thermal Gas Mass Flow Meter in EGR Cooler Test and Analysis System

2014 ◽  
Vol 530-531 ◽  
pp. 225-232
Author(s):  
Ping Song ◽  
Zhi Yong Hao ◽  
Da Yuan Tao ◽  
Xiao Shuai Ren ◽  
Xue Dong Zhang ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Mass Flow ◽  
Outlet Temperature ◽  
Flow Meter ◽  
Overall Heat Transfer Coefficient ◽  
Egr Cooler ◽  
Analysis System ◽  
Experimental Values

This paper studied the principles of thermal gas mass flow meter. According to the car engine EGR cooler working principle, we found out a kind of heat dissipation gas mass flow meter to measure the mass flow quantity of the gas in the EGR cooler test and analysis system which is a newly applied invention patent. We analyzed various parameters of the gas mass flow meter suitable to the system. Meanwhile, in order to verify reliability of the thermal gas mass flow meter in the system, we adopted CFD method to simulate the EGR cooler by using empirical parameters, and collected several related sensor parameters of the EGR cooler in the condition that the inlet temperature was constantly at 368K while the coolant had 4 kinds of degrees. Combining heat empirical formula, we got the EGR cooler outlet temperature and the overall heat transfer coefficient. After comparing the calculated values of the gas path total EGR cooler outlet temperature and heat transfer coefficients with the experimental values, we found that the outlet temperature values of experiment were smaller than the calculated values by averagely 1.17%, while the average experimental values of the overall heat transfer coefficient were 3.1% larger than the calculated values. Thus, this type of mass flow meter has good stability in the newly applied Chinese patent EGR cooler performance test and analysis system.

scholarly journals A numerical model and validation of phase change material integrated thermoelectric radiant cooling panel

2019 ◽  
Vol 111 ◽  
pp. 01001
Author(s):  
Hansol Lim ◽  
Hye-Jin Cho ◽  
Seong-Yong Cheon ◽  
Soo-Jin Lee ◽  
Jae-Weon Jeong
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Numerical Model ◽  
Surface Temperature ◽  
Phase Change ◽  
Transfer Coefficient ◽  
Phase Change Material ◽  
Overall Heat Transfer Coefficient ◽  
Radiant Cooling ◽  
Change Material

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

The Effect of Baffles in Shell and Tube Heat Exchangers

2009 ◽  
Vol 62-64 ◽  
pp. 694-699 ◽  
Author(s):  
E. Akpabio ◽  
I.O. Oboh ◽  
E.O. Aluyor
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Heat Exchangers ◽  
Proper Position ◽  
Process Industries ◽  
Overall Heat Transfer Coefficient ◽  
Shell And Tube ◽  
Optimal Values ◽  
Side Flow

Shell and tube heat exchangers in their various construction modifications are probably the most widespread and commonly used basic heat exchanger configuration in the process industries. There are many modifications of the basic configuration which can be used to solve special problems. Baffles serve two functions: Most importantly, they support the tubes in the proper position during assembly and operation and prevent vibration of the tubes caused by flow-induced eddies, and secondly, they guide the shell-side flow back and forth across the tube field, increasing the velocity and the heat transfer coefficient. The objective of this paper is to find the baffle spacing at fixed baffle cut that will give us the optimal values for the overall heat transfer coefficient. To do this Microsoft Excel 2003 package was employed. The results obtained from previous studies showed that to obtain optimal values for the overall heat transfer coefficient for the shell and tube heat exchangers a baffle cut of 20 to 25 percent of the diameter is common and the maximum spacing depends on how much support the tubes need. This was used to validate the results obtained from this study.

Energy Efficient Hybrid Nanofluids for Tubular Cooling Applications

2014 ◽  
Vol 592-594 ◽  
pp. 922-926 ◽  
Author(s):  
Devasenan Madhesh ◽  
S. Kalaiselvam
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Volume Concentration ◽  
Thermal Characteristics ◽  
Hybrid Nanofluid ◽  
Tubular Heat Exchanger ◽  
Overall Heat Transfer Coefficient ◽  
Flow Through ◽  
Hybrid Nanofluids

Analysis of heat transfer behaviour of hybrid nanofluid (HyNF) flow through the tubular heat exchanger was experimentally investigated. In this analysis the effects of thermal characteristics of forced convection, Nusselt number, Peclet number, and overall heat transfer coefficient were investigated.The nanofluid was prepared by dispersing the copper-titania hybrid nanocomposite (HyNC) in the water. The experiments were performed for various nanoparticle volume concentrations addition in the base fluid from the range of 0.1% to 1.0%. The experimental results show that the overall heat transfer coefficient was found to increases maximum by 30.4%, up to 0.7% volume concentration of HyNC.

Sign in / Sign up

Export Citation Format

Share Document