Numerical Simulation of the Temperature Field and the Flow Field Inside the Domestic Cooling and Heating Unit’s Water Tank

2012 ◽  
Author(s):  
Chao Zhu ◽  
Mo Yang ◽  
Yuwen Zhang ◽  
Jinlong Wang
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Temperature Distribution ◽  
Flow Field ◽  
Water Temperature ◽  
Waste Heat ◽  
Flow Distribution ◽  
Water Tank ◽  
Heating Unit ◽  
Speed Up

A water tank of the domestic cooling and heating unit, which has a helix coil, is used to recover the waste heat of the unit. The temperature field and the flow field in the water tank have great effects on the variation of the water temperature in it. In order to obtain the temperature distribution, the flow distribution and the influencing factors, and then obtain the changing situation of the water temperature, the temperature field and the flow field of the water tank are simulated by using Fluent. The results showed that the water temperature will change with different coil decorate. The numerical model which is created by Fluent is appropriate and could be used to improve the layout of the coil in the water tank and speed up heating.

scholarly journals Studies on the water temperature distribution in small district

1955 ◽  
Vol 11 (2) ◽  
pp. 57-60
Author(s):  
Y. OZAWA ◽  
I. HONDA ◽  
K. MIYAMOTO ◽  
B. CHIBA
Keyword(s):  
Temperature Distribution ◽  
Water Temperature

Study on Criteria of Flushing Phenomena in Boiling Transition by Microwave Heating

2014 ◽  
Author(s):  
Tatsunori Yamaki ◽  
Yutaka Abe ◽  
Akiko Kaneko ◽  
Tomoomi Segawa ◽  
Koichi Kawaguchi ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Microwave Heating ◽  
Flow Structure ◽  
Basic Knowledge ◽  
Distilled Water ◽  
The Future ◽  
The Difference ◽  
Transient Boiling ◽  
Heat Amount

In the Microwave Heating de-nitration (MH) method developed in Japan, a mixed solution of uranyl nitrate and plutonium nitrate (Pu/U mixed nitrate solution) recovered from the spent fuel in the reprocessing plant is converted directly to mixed oxide (MH-MOX) powder. This MH-MOX powder is utilized to fabricate MOX fuel with UO2 powder for FBR. The MH method is accompanied with transient boiling phenomena such as overflow and flushing. Toward high-speed and high-capacity conversion by MH-method in the future, it is required to avoid overflow and flushing and to understand optimal conditions for vessel shape design and microwave output operation. The objective of this paper is to elucidate occurrence criteria of flushing phenomena. At the first step for this objective, basic knowledge of transient boiling phenomena by the MH-method has been mainly acquired with using distilled water. From the results, it is observed that generation of singular bubble triggers flushing and distilled water just before flushing is superheated more than 10 °C in conditions that flushing is confirmed. Also, the water temperature reaches its peak, and it is almost unchanged in conditions that flushing is not confirmed. In no flushing conditions, it is found that the evaporation starts from the point where the water temperature reaches its peak, and water level is decreased gradually. Thus, the difference of thermal characteristics greatly affects whether flushing occurs. The second step, by focusing on the process before flushing occurs, we investigate flow structure, and heat amount through the temperature distribution inside the jelly just after microwave heating. Potassium chloride (KCl) aqueous solution and water are used. KCl solution is electrolyte solution same as reprocessing solution. From the results, upward flow is observed near the center of the solution in the case of the water just after microwave heating. On the other hand, downward flow is observed in the case of KCl solution. As a result of temperature distribution, the water is heated its near center, and KCl solution is heated the around. Thus, it is considered that heat amount of microwave varies depending on solution characteristics, and the difference greatly affects the flow structure. The heat amount and flow structure are critical factors that can determine transient boiling phenomena. We need to investigate transient boiling phenomena of KCl solution in the future.

FACTORS AFFECTING LONGITUDINAL WATER TEMPERATURE DISTRIBUTION DOWNSTEAM FROM A POWER STATION

1974 ◽  
Vol 5 (2) ◽  
pp. 77-97 ◽  
Author(s):  
CHARLES G. AMATO
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Sensible Heat ◽  
Power Station ◽  
Factors Affecting ◽  
Heat Effects

The magnitude of reject heat, the distances to which sensible heat effects may be experienced in a river and alternate means of rejecting heat are discussed.

scholarly journals Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

2018 ◽  
Vol 30 ◽  
pp. 01015
Author(s):  
Joanna Bąk
Keyword(s):  
Water Pollution ◽  
Temperature Distribution ◽  
Water Temperature ◽  
Water Contamination ◽  
Temperature Measurements ◽  
Temperature Changes ◽  
Air Temperatures ◽  
Single Temperature ◽  
Long Time ◽  
Number Of Bacteria

At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water – air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

Vertical Thermal Distribution at the near Dam Region of the Three Gorges Reservoir in the Initial Impoundment Period

2014 ◽  
Vol 889-890 ◽  
pp. 1649-1652
Author(s):  
L.Q. Dai ◽  
H.C. Dai ◽  
B.W. Wang
Keyword(s):  
Temperature Distribution ◽  
Water Temperature ◽  
Temperature Difference ◽  
Three Gorges Reservoir ◽  
Thermal Structure ◽  
Maximum Temperature ◽  
Three Gorges ◽  
Bottom Water Temperature ◽  
The Three Gorges Reservoir ◽  
The Three Gorges

Water temperature plays a crucial role in water ecological environment both in the reservoir and downstream area. Three Gorges Project (TGP) is the largest hydraulic engineering in the world, and changes of water quality attract much more attention, especially in the thermal structure since initial impoundment in 2003. In order to clearly understand water temperature distribution after the initial impoundment in the Three Gorges Reservoir (TGR), we monitored the temperature distribution of the Taipingxi section which was not far from the dam from early April to the end of July in 2004. According to the analyzing of the monitoring data of transverse and vertical temperature variation, we could find that when water level went up to 135m above sea level (a.s.l.) or 139m in the initial impoundment phase, the temperature mixed uniformly in transverse direction. Excepting April, there was basically had no temperature difference in vertical direction, even in April, the maximum temperature difference was only 1.39°C within 100 meters (April 22), the average temperature gradient was only 0.014°C/m; Both the temperature of water and atmosphere have similar variation tendency, but the response of the water temperature to atmosphere is delayed, especially the bottom water temperature. The result indicate that the reservoir displayed a mixed thermal structure during initial impoundment phase, therefore, the release had no change before and after impoundment, also had little influence on the aquatic organism and crops at downstream , the work provide a scientific basis for the development of pollution control and ecological protection measure.

scholarly journals Numerical simulation on effect of irrigation conditions on water temperature distribution in a paddy field

2022 ◽  
Author(s):  
Kazuhiro Nishida ◽  
Shuichiro Yoshida ◽  
Sho Shiozawa
Keyword(s):  
Water Management ◽  
Numerical Simulation ◽  
Temperature Distribution ◽  
Water Temperature ◽  
Physical Model ◽  
Irrigation Water ◽  
Paddy Field ◽  
Meteorological Conditions ◽  
Paddy Fields ◽  
Water Amount

AbstractWater management methods regulate water temperature in paddy fields, which affects rice growth and the environment. To understand the effect of irrigation conditions on water temperature in a paddy field, water temperature distribution under 42 different irrigation models including the use of ICT water management, which enables remote and automatic irrigation, was simulated using a physical model of heat balance. The following results were obtained: (1) Irrigation water temperature had a more significant effect on paddy water temperature close to the inlet. As the distance from the inlet increased, the water temperature converged to an equilibrium, which was determined by meteorological conditions and changes in water depth. (2) Increasing the irrigation rate with higher irrigation water amount increased the extent and magnitude of the effects of the irrigation water temperature. (3) When total irrigation water amount was the same, increasing the irrigation rate decreased the time-averaged temperature gradient effect over time across the paddy field. (4) Irrigation during the lowest and highest paddy water temperatures effectively decreased and increased the equilibrium water temperature, respectively. The results indicate that irrigation management can be used to alter and control water temperature in paddy fields, and showed the potential of ICT water management in enhancing the effect of water management in paddy fields. Our results demonstrated that a numerical simulation using a physical model for water temperature distribution is useful for revealing effective water management techniques under various irrigation methods and meteorological conditions.

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