Experimental Investigation of Local Fluid Temperature Profiles in Sub-Cooled Boiling Flows

2019 ◽  
Author(s):  
Z. Dang ◽  
J. Du ◽  
M. Ishii ◽  
Y. Zhao
Keyword(s):  
Experimental Investigation ◽  
Temperature Profiles ◽  
Fluid Temperature

scholarly journals An Experimental Investigation of the External Wind Effects on the Ceiling Temperature Distribution of Fire-Induced Thermal Flow in a Corridor Connected to a Compartment

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1826
Author(s):  
Bei Cao ◽  
Xiaodong Zhou ◽  
Yubiao Huang ◽  
Yuan Zheng ◽  
Kai Ye ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
Temperature Distribution ◽  
Wind Velocity ◽  
Shielding Effect ◽  
Temperature Profiles ◽  
Building Structures ◽  
Thermal Flow ◽  
Ceiling Temperature ◽  
Higher Temperature

Fire-induced thermal flow is the greatest threat to trapped people and the heat-resistant quality of building structures. This paper presents an experimental investigation of the effects of external wind on the ceiling temperature distribution of fire-induced thermal flow in a one-sixth scale corridor connected to a compartment. In the experiments, the fire source was placed in the compartment with hot thermal flow spilled into the connected corridor. The heat release rate (HRR) was changed from 10 to 20 kW and the external wind velocity was changed from 0 to 2.09 m/s. The ends of the corridor could be adjusted to be fully or partially open to the environment with dam-boards arranged at the ends of the corridor. An effective corridor HRR, Qcorridor, was defined to account for the amount of the spilled plume into the corridor. Results show that the temperature under the ceiling changed in a non-monotonic way with wind velocity: it first increased and then decreased with wind velocity. It was revealed that the dam-boards at the corridor opening had an evidently shielding effect, leading to higher temperature compared to the fully open environment. Finally, uniform correlations are proposed for predicting the attenuation law of ceiling temperature profiles in corridors for different wind conditions.

Experimental Investigation on Rapid Evaporation of High-Pressure Liquids due to Depressurization

2012 ◽  
Author(s):  
Qiaoling Zhang ◽  
Qincheng Bi ◽  
Zesen Nie ◽  
Jun Liang ◽  
Yajun Guo ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
High Speed ◽  
Initial Conditions ◽  
Initial Pressure ◽  
Fluid Temperature ◽  
Shape Variation ◽  
Nitrogen Gas ◽  
Test Vessel ◽  
Variation Characteristics

This paper reports an experimental investigation of rapid evaporation process of high-pressure ethanol liquid during depressurization. The study focused on pressure and temperature transients with the influence of different initial conditions, and the shape variation was recorded via a high speed camera. During an experiment, the ethanol liquid was contained in a small round tube with a diameter 10mm in the test vessel, and a thermocouple was put within the fluid which was used to measure the fluid temperature during the depressurization. The predetermined pressure was provided by the high-pressure nitrogen gas, and the process of quick depressurization was started by opening the magnetic valve, which was connected with the test vessel. The transitions of the pressure and the fluid temperature were recorded by the NI data collection system. According to the experimental results, during the fast pressure drop, with the same initial temperature and other test conditions, the higher the initial pressure is, the faster the liquid temperature decreases, and the lower the minimum temperature reaches. In addition, the effect of initial fluid conditions, initial environmental pressure on temperature transition and so on are summed up and are experimentally analyzed on the fluid temperature change under the same test equipment. Also, the variation characteristics of kerosene fluid were compared with ethanol liquid under the same experiment conditions.

scholarly journals Modified methodology for determining the temperature profiles of inverted u-tubes steam generators used in pwr power plants

2021 ◽  
Vol 9 (2B) ◽  
Author(s):  
Marcos Filardy Curi
Keyword(s):  
Heat Exchanger ◽  
Phase Change ◽  
Power Plants ◽  
Flow Direction ◽  
Saturated Steam ◽  
Geometrical Parameters ◽  
Temperature Profiles ◽  
Fluid Temperature ◽  
Secondary Circuit ◽  
Steam Generators

The most common and reliable methodology for determining temperature profiles of Inverted U-tubes Steam Generators is using Computational Fluid Dynamics (CFD) programs. In this work, we developed a modified methodology, using the Wolfram Mathematica software, in order to determine, with good approximation, the temperature profiles of these kind of equipment. The first step was to determine expressions for the physical properties of the water in the operational conditions, like density, thermal conductivity, specific heat and dynamic viscosity. Geometrical parameters like tubes diameter and sub-channel flowing area, as well as the flow parameters like flow mass of primary and secondary fluid, were also considered for determining the numbers of Reynolds, Prandtl, Nusselt and, consequently, the variation of convective coefficients and the global heat transfer coefficient. With subroutines that use the method of the lines we were able to solve the partial differential equations applied to parallel and countercurrent heat exchangers with no phase change. The U-tubes SG were divided in two regions which the first one was calculated considering a parallel heat exchanger and the second one was calculated considering a countercurrent heat exchanger, depending on the flow direction of the primary and secondary circuit. During the phase change, a constant variation of the enthalpy was considered, making the primary fluid temperature decrease following a linear behavior. Using the developed methodology called “Enthalpy Ruler”, the encountered results were considered adequate, since the defined lengths are compatible with the constant variation of the enthalpy from the compressed liquid to saturated steam.

Aerodynamics and Heat Transfer for a Cooled One and One-Half Stage High-Pressure Turbine—Part I: Vane Inlet Temperature Profile Generation and Migration

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
R. M. Mathison ◽  
C. W. Haldeman ◽  
M. G. Dunn
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Temperature Profile ◽  
Film Cooling ◽  
Leading Edge ◽  
Inlet Temperature ◽  
Temperature Profiles ◽  
Fluid Temperature ◽  
High Pressure Turbine ◽  
Wide Range

As controlled laboratory experiments using full-stage turbines are expanded to replicate more of the complicated flow features associated with real engines, it is important to understand the influence of the vane inlet temperature profile on the high-pressure vane and blade heat transfer as well as its interaction with film cooling. The temperature distribution of the incoming fluid governs not only the input conditions to the boundary layer but also the overall fluid migration. Both of these mechanisms have a strong influence on surface heat flux and therefore component life predictions. To better understand the role of the inlet temperature profile, an electrically heated combustor emulator capable of generating uniform, radial, or hot streak temperature profiles at the high-pressure turbine vane inlet has been designed, constructed, and operated over a wide range of conditions. The device is shown to introduce a negligible pressure distortion while generating the inlet temperature conditions for a stage-and-a-half turbine operating at design-corrected conditions. For the measurements described here, the vane is fully cooled and the rotor purge flow is active, but the blades are uncooled. Detailed temperature measurements are obtained at rake locations upstream and downstream of the turbine stage as well as at the leading edge and platform of the blade in order to characterize the inlet temperature profile and its migration. The use of miniature butt-welded thermocouples at the leading edge and on the platform (protruding into the flow) on a rotating blade is a novel method of mapping a temperature profile. These measurements show that the reduction in fluid temperature due to cooling is similar in magnitude for both uniform and radial vane inlet temperature profiles.

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