scholarly journals Research on the Heating of Deicing Fluid in a New Reshaped Coiled Tube

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mengli Wu ◽  
Chiyu Wang ◽  
Yunpeng Li ◽  
Qi Nie
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Heating System ◽  
High Viscosity ◽  
Negative Influence ◽  
Heating Time ◽  
Temperature Fields ◽  
Outlet Temperature ◽  
Coiled Tube ◽  
Deicing Fluid

Aircraft ground deicing operation is significant to ensure civil flight safety in winter. Helically coiled tube is the important heat exchanger in Chinese deicing fluid heating system. In order to improve the deicing efficiency, the research focuses on heat transfer enhancement of deicing fluid in the tube. Based on the field synergy principle, a new reshaped tube (TCHC) is designed by ring-rib convex on the inner wall. Deicing fluid is high viscosity ethylene-glycol-based mixture. Because of the power function relation between high viscosity and temperature, viscosity has a negative influence on heat transfer. The number of ring-ribs and inlet velocity are two key parameters to the heat transfer performance. For both water and ethylene glycol, the outlet temperature rises when the number of ring-ribs increases to a certain limit. However, the increasing of velocity reduces heating time, which results in lower outlet temperature. The heating experiment of the original tube is conducted. The error between experiment and simulation is less than 5%. The outlet temperature of TCHC increases by 3.76%. As a result, TCHC efficiently promotes the coordination of velocity and temperature fields by changing the velocity field. TCHC has enhanced heat transfer of high viscosity deicing fluid.

Influence of Geometrical Parameters on Heat Transfer of Transversely Corrugated Helically Coiled Tube for Deicing Fluid

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Mengli Wu ◽  
Qi Nie ◽  
Yunpeng Li ◽  
Xianqu Yue ◽  
Weibin Chen ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Orthogonal Experiment ◽  
Resistance Coefficient ◽  
Diameter Ratio ◽  
Geometrical Parameters ◽  
Outlet Temperature ◽  
Field Synergy ◽  
Coiled Tube ◽  
Helically Coiled Tube ◽  
Deicing Fluid

In order to ensure flight safety in cold winter, aircraft ground deicing is crucial and necessary. In Chinese deicing fluid heating system, the helically coiled tube is paramount exchanger to heat deicing fluid. The deicing fluid is ethylene-glycol-based mixture with high viscosity. Aiming at heat transfer enhancement of deicing fluid, ring rib is formed by an embossed tube wall toward the internal of the tube; thus, transversely corrugated helically coiled tube (TCHC) is achieved. Depth and width are two key geometrical parameters of ring rib. Based on field synergy principle, the influence of depth–diameter ratio (H/D) and width-diameter ratio (w/D) is investigated through numerical simulation. The results show that outlet temperature, mean convection heat transfer coefficient, and Nusselt number have similar trends, which first increase and then decrease nonlinearly. The variation of flow resistance coefficient is inversely proportional to Reynolds number. Especially, the effect of H/D is more significant than that of w/D. Field synergy angle and velocity field are also analyzed to reveal the mechanism of heat transfer. TCHC performs better than the original tube. Orthogonal experiment calculates the outlet temperature of TCHC when H/D and w/D change. The combination of H/D=0.075 and w/D=0.5 is best solution. TCHC effectively enhances heat transfer of deicing fluid. Therefore, TCHC is beneficial to improve the deicing efficiency and ensure the flight punctuality.

Fluid Motion and Heat Transfer of a High-Viscosity Fluid in a Rectangular Tank on a Ship With Oscillating Motion

1987 ◽  
Vol 109 (3) ◽  
pp. 635-641 ◽  
Author(s):  
S. Akagi ◽  
K. Uchida
Keyword(s):  
Heat Transfer ◽  
Numerical Solutions ◽  
Fluid Motion ◽  
Heating System ◽  
High Viscosity ◽  
Thermal Design ◽  
Basic Equations ◽  
Oil Tanks ◽  
Oscillating Motion ◽  
Viscosity Fluid

Fluid motion and heat transfer of a high-viscosity fluid contained in a two-dimensional rectangular ship’s tank subjected to oscillating motion are investigated by a finite difference technique. The study is motivated by the thermal design of the heating system of oil tanks on a tanker which is moving in a wavy sea. The bottom of the tank is heated and its side walls are cooled. The motion of the tank is assumed to be a simple harmonic rolling motion. The isotherms and flow velocity vectors are determined by numerical solutions of the basic equations describing the convection flows in a tank with oscillating motion. The heat transfer rates to the tank walls are predicted. The influence of the frequency of the oscillating motion on the heat transfer rate is examined.

Assessment of Heat Saving from Intermittent Heating of Buildings with Different Thermal Stability

2018 ◽  
Vol 931 ◽  
pp. 910-913
Author(s):  
Elena G. Malyavina
Keyword(s):  
Heat Transfer ◽  
Thermal Stability ◽  
Heat Resistance ◽  
Heat Supply ◽  
Operation Mode ◽  
Internal Heat ◽  
Heating System ◽  
Heating Time ◽  
The Past ◽  
Intermittent Heating

Modern buildings are characterized by a high resistance to the heat transfer of the outdoor enclosing structures, a high density of translucent structures, which put the intermittent room heating in the conditions when the formerly made surveys of the past years are not sufficient. The heat resistance of the building enclosing structures reduces the savings in the intermittent heat supply for heating needs, as it requires an intensive heating before the start of the working days. The more the power of a heating system is and the shorter the heating time is, the more economical the operation mode of this system is. The less the internal heat resistance of the room is, the greater the heat economy is. The thermal savings are bigger, if the room cools quicker after reduction of the heat supply.

Research on Energy and Environment Engineering with Heat Transfer in the Geothermal Heating System with Horizontal Wells

2014 ◽  
Vol 908 ◽  
pp. 461-464 ◽  
Author(s):  
Ming Ming Lv ◽  
Shu Zhong Wang ◽  
Xiang Rong Luo ◽  
Ming Luo
Keyword(s):  
Heat Transfer ◽  
Heat Exchange ◽  
Flow Rate ◽  
Horizontal Well ◽  
Horizontal Wells ◽  
Heating System ◽  
Transfer Model ◽  
Outlet Temperature ◽  
Linear Change ◽  
Geothermal Heating

Geothermal heating system with horizontal wells doesnt extract ground water and is not affected by the distribution of geothermal resources, which is a closed-loop and environment-friendly system. In this paper, the heat exchange between the horizontal well and rock in the geothermal heating system with horizontal wells has been studied, the heat transfer model has been built, and the heat transfer at different flow rates of water has been calculated. The results show that the outlet temperature of the horizontal well increases with the decrease of the flow rate, and the flux of heat exchange decreases with the decrease of the flow rate. The outlet temperature and the flux of heat transfer have basically the same tendency with time. The three stages are respectively rapidly change stage, moderate change stage and linear change stage.

scholarly journals Modeling of temperature profiles and efficiency of heat transfer equipment with intensifiers

2020 ◽  
Vol 22 (2) ◽  
pp. 12-18
Author(s):  
T. M. Farakhov ◽  
A. G. Laptev
Keyword(s):  
Heat Transfer ◽  
Cell Model ◽  
Experimental Studies ◽  
High Viscosity ◽  
Hot Water ◽  
Temperature Fields ◽  
Turbulent Regime ◽  
Temperature Profiles ◽  
Heating And Cooling ◽  
Nominal Size

The problem of determination of temperature fields in the flow and efficiency of heat exchangers with intensification by metal chaotic packings is considered. Results of experimental studies of the heating of industrial oil with hot water in a "pipe-in-pipe" heat exchanger, where a chaotic packing of nominal size 6 mm is placed in the internal pipe, are presented. The packing, due to turbulence in the flow of oil, provides transition from the laminar to the turbulent regime and a significant increase in heat transfer coefficient (by 15-20 times). For calculating temperature profiles in channels, a cell model of the flow structure is written, where the main parameters are thermal number of transfer units and number of complete mixing cells. Expressions are given for calculating these parameters in pipes with chaotic packings. Results of calculating temperature profiles for various flowrates of the heated oil are presented and satisfactory agreement with experimental data is shown. The calculation of temperature fields makes it possible to take into account a change in thermophysical properties of flows along the length of the channels, which is especially important for hydrocarbon mixtures with high viscosity and large Prandtl numbers. The presented mathematical model allows to take into account the structure of heat carrier flows in apparatus with intensifiers and to calculate thermal efficiency of the processes of heating and cooling the media.

Thermal Effects on Micro-Sized Tesla Valves

2014 ◽  
Author(s):  
Basil J. Paudel ◽  
Tausif Jamal ◽  
Scott M. Thompson ◽  
D. Keith Walters
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
High Performance ◽  
Check Valve ◽  
Channel Cross Section ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Working Fluids ◽  
In Series ◽  
Tesla Valve

The Tesla valve is a no-moving-parts check valve that may be used in a variety of mini- or micro-fluidic applications for passive flow promotion and/or rectification. Its effectiveness is measured via its diodicity which depends on the Reynolds number and its unique design features. The valve may be aligned in-series to further increase its fluidic diode effect — forming a multi-staged Tesla valve (MSTV). Using Computational Fluid Dynamics (CFD) and high performance computing, the current investigation assesses the effects of heat transfer on the overall MSTV diodicity and the extent to which the MSTV enhances heat transfer. For laminar, single-phase flow, thermal boundary conditions were imposed to include an isothermal MSTV wall at 20 °C and a flow inlet temperature of either: 20 °C, 50 °C or 80 °C. The flow outlet temperature and MSTV diodicity was then determined for the various inlet temperatures, Reynolds numbers, working fluids (i.e. Prandtl number, Pr) and number of Tesla valves in MSTV. Working fluids were varied between: air (Pr ∼ 0.7), water (Pr ∼ 5) and ethylene glycol (Pr ∼ 200). The MSTV channel cross-section was set to 1 mm2 and the valve-to-valve distance was held constant while varying the number of Tesla valves. Results indicate that there is a significant decrease in diodicity for water and ethylene glycol as the inlet temperature increases, suggesting higher performance of the MSTV when there is less heat transfer. For air, MSTV performance was found to actually increase with temperature. Due to mixing effects, the MSTV was demonstrated to function as an efficient heat exchanger relative to an un-valved mini-channel of similar size.

Thermal analysis of high viscosity deicing fluid in the heating system

2018 ◽  
Vol 134 (3) ◽  
pp. 2147-2156 ◽  
Author(s):  
Mengli Wu ◽  
Chiyu Wang ◽  
Qi Nie ◽  
Yunpeng Li ◽  
Rui Zhou
Keyword(s):  
Thermal Analysis ◽  
Heating System ◽  
High Viscosity ◽  
Deicing Fluid

A study on heating and determining the temperature generation on the sheet metal before the deep drawing process

2020 ◽  
Vol 34 (22n24) ◽  
pp. 2040133
Author(s):  
The-Thanh Luyen ◽  
Thi-Bich Mac ◽  
Tien-Long Banh ◽  
Duc-Toan Nguyen
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Deep Drawing ◽  
High Strength ◽  
Heating System ◽  
Local Heat ◽  
Heating Time ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Processing Solution

Thermal-assisted machining (TAM) is an effective processing solution to improve productivity and product quality made from materials with high strength and hardness. This method is widely used in nonchip machining such as forging, stamping, deep drawing, etc. For the method of heating on the molds, it is possible to control local heat or uniform heat on the workpiece. However, the calculation of heat capacity, heat transfer as well as the heating time to achieve the temperature on the workpiece is necessary to design suitable molds and heating system. This study focuses on a heating system that uses single-sided thermostatic heating rods to heat the molds, verify the effect of the heating time on the temperature of the workpieces and then control the temperature on the workpieces at various heat levels through a heating control system. Thereby, this study proposes to build a mathematical model between temperature and heating time on the workpiece.

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