scholarly journals Pengaruh Jenis Material Pipa Pendingin Terhadap Distribusi Temperatur di Dalam Beton Yang Didinginkan dengan Sistem Post Cooling

2021 ◽  
Vol 1 (1) ◽  
pp. 14-23
Author(s):  
Ratnawati
Keyword(s):  
Cooling System ◽  
Water Discharge ◽  
Cooling Water ◽  
Concrete Surface ◽  
Heat Of Hydration ◽  
Mass Concrete ◽  
Cooling Pipe ◽  
Higher Temperature ◽  
Materials Used ◽  
Concrete Casting

Mass concrete is a concrete casting with a large enough volume, usually used for foundations, bridges,dams and so on. The heat of hydration in the mass concrete causes a temperature difference between the inside and the outside of the concrete surface. This can cause cracks in the concrete,where the temperature inside the concrete has a higher temperature rise than the outer surface yhat is in contact with the environment. One way to control the temperature of the concrete is to use a post cooling system.Post cooling system design requires knowledge of temperatur distribution in concrete. The research was conducted by varying the cooling pipe materials used,namely steel,PVC,and PEX where the cooling water discharge and temperatur were constant.The result of the research that have been carried out show that with the same cooling water discharge and temperature,concrete with PVC cooling has a higher temperature than PEX cooling pipe or steel.

scholarly journals Precise Simulation of Heat-Flow Coupling of Pipe Cooling in Mass Concrete

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5142
Author(s):  
Peng Yu ◽  
Ruiqing Li ◽  
Dapeng Bie ◽  
Xiancai Liu ◽  
Xiaomin Yao ◽  
...  
Keyword(s):  
Heat Flow ◽  
Temperature Gradient ◽  
Temperature Control ◽  
Cooling Water ◽  
Mass Concrete ◽  
Finite Element Software ◽  
Flow Coupling ◽  
Cooling Pipe ◽  
Cooling Effects ◽  
Precise Simulation

For a long time, temperature control and crack prevention of mass concrete is a difficult job in engineering. For temperature control and crack prevention, the most effective and common-used method is to embed cooling pipe in mass concrete. At present, there still exists some challenges in the precise simulation of pipe cooling in mass concrete, which is a complex heat-flow coupling problem. Numerical simulation is faced with the problem of over-simplification and inaccuracy. In this study, precise simulation of heat-flow coupling of pipe cooling in mass concrete is carried out based on finite element software COMSOL Multiphysics 5.4. Simulation results are comprehensively verified with results from theoretical solutions and equivalent algorithms, which prove the correctness and feasibility of precise simulation. Compared with an equivalent algorithm, precise simulation of pipe cooling in mass concrete can characterize the sharp temperature gradient around cooling pipe and the temperature rise of cooling water along pipeline more realistically. In addition, the cooling effects and local temperature gradient under different water flow (0.60 m3/h, 1.20 m3/h, and 1.80 m3/h) and water temperature (5 °C, 10 °C, and 15 °C) are comprehensively studied and related engineering suggestions are given.

Modelling the Consequence of Cooling Water Discharge from the “Vendsyssel” Power Plant

1983 ◽  
Vol 15 (10) ◽  
pp. 177-196 ◽  
Author(s):  
Anders Malmgren-Hansen ◽  
K I Dahl-Madsen
Keyword(s):  
Power Plant ◽  
Primary Production ◽  
Mathematical Models ◽  
Growth Model ◽  
Power Plants ◽  
Considerable Increase ◽  
Cooling System ◽  
Water Discharge ◽  
Cooling Water ◽  
Zooplankton Growth

Discharge of cooling water from power plants has various effects on the ecosystem in coastal areas. The effect on primary production due to the rise in temperature in the outlet area and the decimation of zooplankton organisms passing through the cooling system of the power plant can be calculated by means of mathematical models. Calculations of the consequences of a considerable increase in cooling water discharge from the “Vendsyssel” power plant are presented. The decimation of zooplankton is calculated by means of a combined 2-dimensional hydraulic and zooplankton-growth model. Calculations of the effects on primary production are carried out by use of a combined 1-dimensional hydraulic and eutrophication model.

Assessment of thermal behavior of a cooling system to reduce thermal fatigue cracks in aluminum injection molds

2020 ◽  
pp. 75-86
Author(s):  
Sergio Antonio Camargo ◽  
Lauro Correa Romeiro ◽  
Carlos Alberto Mendes Moraes
Keyword(s):  
Thermal Fatigue ◽  
Cooling System ◽  
Fatigue Cracks ◽  
Cooling Water ◽  
Thermal Conditions ◽  
Thermal Gradients ◽  
Ansys Software ◽  
Cooling Systems ◽  
Thermal Fatigue Cracks ◽  
Number Of Cycles

The present article aimed to test changes in cooling water temperatures of males, present in aluminum injection molds, to reduce failures due to thermal fatigue. In order to carry out this work, cooling systems were studied, including their geometries, thermal gradients and the expected theoretical durability in relation to fatigue failure. The cooling system tests were developed with the aid of simulations in the ANSYS software and with fatigue calculations, using the method of Goodman. The study of the cooling system included its geometries, flow and temperature of this fluid. The results pointed to a significant increase in fatigue life of the mold component for the thermal conditions that were proposed, with a significant increase in the number of cycles, to happen failures due to thermal fatigue.

Hydraulic model of a water cooling system in a chemical plant

1988 ◽  
Vol 53 (4) ◽  
pp. 788-806
Author(s):  
Miloslav Hošťálek ◽  
Jiří Výborný ◽  
František Madron
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Cooling Water ◽  
Graph Algorithm ◽  
Automatic Generation ◽  
Hydraulic Calculation ◽  
Return Flow ◽  
Flow Rates ◽  
Pressure Losses ◽  
Controlled Flow

Steady state hydraulic calculation has been described of an extensive pipeline network based on a new graph algorithm for setting up and decomposition of balance equations of the model. The parameters of the model are characteristics of individual sections of the network (pumps, pipes, and heat exchangers with armatures). In case of sections with controlled flow rate (variable characteristic), or sections with measured flow rate, the flow rates are direct inputs. The interactions of the network with the surroundings are accounted for by appropriate sources and sinks of individual nodes. The result of the calculation is the knowledge of all flow rates and pressure losses in the network. Automatic generation of the model equations utilizes an efficient (vector) fixing of the network topology and predominantly logical, not numerical operations based on the graph theory. The calculation proper utilizes a modification of the model by the method of linearization of characteristics, while the properties of the modified set of equations permit further decrease of the requirements on the computer. The described approach is suitable for the solution of practical problems even on lower category personal computers. The calculations are illustrated on an example of a simple network with uncontrolled and controlled flow rates of cooling water while one of the sections of the network is also a gravitational return flow of the cooling water.

Study on the Heat Transfer in the Water Pool Type Reactor Cavity Cooling System of the Very High Temperature Gas Cooled Reactor

2005 ◽  
Author(s):  
H. K. Cho ◽  
D. U. Seo ◽  
M. O. Kim ◽  
G. C. Park
Keyword(s):  
Heat Transfer ◽  
Forced Convection ◽  
Cooling System ◽  
Reactor Vessel ◽  
Water Pool ◽  
Cooling Pipe ◽  
Cavity Cooling ◽  
The Heat Transfer Coefficient ◽  
Pool Type ◽  
High Temperature Gas

In the HTGR (High Temperature Gas Cooled Reactor), the Reactor Cavity Cooling System (RCCS) is equipped to remove the heat transferred from the reactor vessel to the structure of the containment. The function of the RCCS is to dissipate the heat from the reactor cavity during normal operation including shutdown. The system also removes the decay heat during the loss of forced convection (LOFC) accident. A new concept of the water pool type RCCS was proposed at Seoul National University. The system mainly consists of two parts, water pool located between the containment and reactor vessel and five trains of air cooling system installed in the water pool. In normal operations, the heat loss from the reactor vessel is transferred into the water pool via cavity and it is removed by the forced convection of air flowing through the cooling pipes. During the LOFC accident, the after heat is passively removed by the water tank without the forced convection of air and the RCCS water pool is designed to provide sufficient passive cooling capacity of the after heat removal for three days. In the present study, experiments and numerical calculations using CFX5.7 for the water pool and cooling pipe were performed to investigate the heat transfer characteristics and evaluate the heat transfer coefficient model of the MARS-GCR (Multi-dimensional Analysis of Reactor Safety for Gas Cooled Reactor Analysis) which was developed for the safety analysis of the gas cooled reactor. From the results of the experiments and CFX calculations, heat transfer coefficients inside the cooling pipe were calculated and those were used for the assessment for the heat transfer coefficient model of the MARS-GCR.

scholarly journals Revisiting the Effect of Slag in Reducing Heat of Hydration in Concrete in Comparison to Other Supplementary Cementitious Materials

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1847 ◽  
Author(s):  
Hoon Moon ◽  
Sivakumar Ramanathan ◽  
Prannoy Suraneni ◽  
Chang-Seon Shon ◽  
Chang-Joon Lee ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Temperature Rise ◽  
Adiabatic Calorimetry ◽  
Blast Furnace Slag ◽  
Isothermal Calorimetry ◽  
Heat Of Hydration ◽  
Supplementary Cementitious Materials ◽  
Maximum Temperature ◽  
Mass Concrete ◽  
Furnace Slag

Blast furnace slag (SL) is an amorphous calcium aluminosilicate material that exhibits both pozzolanic and latent hydraulic activities. It has been successfully used to reduce the heat of hydration in mass concrete. However, SL currently available in the market generally experiences pre-treatment to increase its reactivity to be closer to that of portland cement. Therefore, using such pre-treated SL may not be applicable for reducing the heat of hydration in mass concrete. In this work, the adiabatic and semi-adiabatic temperature rise of concretes with 20% and 40% SL (mass replacement of cement) containing calcium sulfate were investigated. Isothermal calorimetry and thermal analysis (TGA) were used to study the hydration kinetics of cement paste at 23 and 50 °C. Results were compared with those with control cement and 20% replacements of silica fume, fly ash, and metakaolin. Results obtained from adiabatic calorimetry and isothermal calorimetry testing showed that the concrete with SL had somewhat higher maximum temperature rise and heat release compared to other materials, regardless of SL replacement levels. However, there was a delay in time to reach maximum temperature with increasing SL replacement level. At 50 °C, a significant acceleration was observed for SL, which is more likely related to the pozzolanic reaction than the hydraulic reaction. Semi-adiabatic calorimetry did not show a greater temperature rise for the SL compared to other materials; the differences in results between semi-adiabatic and adiabatic calorimetry are important and should be noted. Based on these results, it is concluded that the use of blast furnace slag should be carefully considered if used for mass concrete applications.

Effective Fuel Consumption by Improving Cooling Water Flow Rate in IC Engine

2015 ◽  
Vol 812 ◽  
pp. 112-117
Author(s):  
K.M. Kumar ◽  
P. Venkateswaran ◽  
P. Suresh
Keyword(s):  
Flow Rate ◽  
Cooling System ◽  
Water Flow Rate ◽  
Research Work ◽  
Cooling Water ◽  
Major Change ◽  
Clear Understanding ◽  
Water Pump ◽  
Ic Engine ◽  
Cooling Water Flow Rate

The coolant (water) pump assumes an important role of cooling system in IC engines. With upgrading of the engine power by turbocharging and turbo inter cooling, the water pump capacity needs to be increased corresponding to the power. This capacity enhancement has to be achieved without calling for a major change in the existing water pump, envelop and related fitment details. This requires a clear understanding of centrifugal pump for its performance parameter. One such engine is upgraded by turbocharging from 195PS to 240PS @2200 rpm. Improving water pump flow by changing the impeller dimensions, impeller casing, increase the suction, delivery pipe diameter had been done. Validation of the water pump in its actual engine installation was taken up as a part of the research work. Flow rate comparison of the new pump with the existing pump was made and the results were analyzed. The new water pump gives better flow rates for the engine speeds up to1800 rpm, beyond which the flow rate is slightly lesser than the existing pump.

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