Analysis of Cooling Water Temperature Impact on Computing Performance and Energy Consumption

Author(s):  
Jorji Nonaka ◽  
Toshihiro Hanawa ◽  
Fumiyoshi Shoji
2021 ◽  
Vol 13 (11) ◽  
pp. 5957
Author(s):  
Tomas Mauder ◽  
Michal Brezina

Production of overall CO2 emissions has exhibited a significant reduction in almost every industry in the last decades. The steelmaking industry is still one of the most significant producers of CO2 emissions worldwide. The processes and facilities used at steel plants, such as the blast furnace and the electric arc furnace, generate a large amount of waste heat, which can be recovered and meaningfully used. Another way to reduce CO2 emissions is to reduce the number of low-quality steel products which, due to poor final quality, need to be scrapped. Steel product quality is strongly dependent on the continuous casting process where the molten steel is converted into solid semifinished products such as slabs, blooms, or billets. It was observed that the crack formation can be affected by the water cooling temperature used for spray cooling which varies during the year. Therefore, a proper determination of the cooling water temperature can prevent the occurrence of steel defects. The main idea is based on the utilization of the waste heat inside the steel plant for preheating the cooling water used for spray cooling in the Continuous Casting (CC) process in terms of water temperature stabilization. This approach can improve the quality of steel and contribute to the reduction of greenhouse gas emissions. The results show that, in the case of billet casting, a reduction in the cooling water consumption can be also reached. The presented tools for achieving these goals are based on laboratory experiments and on advanced numerical simulations of the casting process.


Author(s):  
Jungho Lee ◽  
Cheong-Hwan Yu ◽  
Sang-Jin Park

Water spray cooling is an important technology which has been used in a variety of engineering applications for cooling of materials from high-temperature nominally up to 900°C, especially in steelmaking processes and heat treatment in hot metals. The effects of cooling water temperature on spray cooling are significant for hot steel plate cooling applications. The local heat flux measurements are introduced by a novel experimental technique in which test block assemblies with cartridge heaters and thermocouples are used to measure the heat flux distribution on the surface of hot steel plate as a function of heat flux gauge. The spray is produced from a fullcone nozzle and experiments are performed at fixed water impact density of G and fixed nozzle-to-target spacing. The results show that effects of water temperature on forced boiling heat transfer characteristics are presented for five different water temperatures between 5 to 45°C. The local heat flux curves and heat transfer coefficients are also provided to a benchmark data for the actual spray cooling of hot steel plate cooling applications.


2020 ◽  
Vol 18 (4) ◽  
pp. 578-585
Author(s):  
Madina Shavdinova ◽  
Konstantin Aronson ◽  
Nina Borissova

The condensing unit is one of the most important elements of the steam turbine of a combined heat and power plant. Defects in elements of the condensing unit lead to disturbances in the steam turbine operation, its failures and breakdowns, as well as efficiency losses of the plant. Therefore, the operating personnel need to know the cause of the malfunction and to correct it immediately. There are no diagnostic models of condensers in the Republic of Kazakhstan at the moment. In this regard, a mathematical model of a condenser based on the methodology of Kaluga Turbine Plant (KTP) has been developed. The mathematical model makes it possible to change the input parameters, plot dependency diagrams, and calculate the plant efficiency indicators. The mathematical model of the condenser can be used to research ways for the improvement of the condensing unit efficiency, for diagnostic purposes of the equipment condition, for the energy audit conduction of the plant, and in the training when performing virtual laboratory research. Using static data processing by linear regression method we obtain that the KTP methodology of condenser calculation is fair at cooling water temperature from 20 °C to 24 °C, but at cooling water temperature from 20 °C to 28 °C, the methodology of JSC "All-Russia Thermal Engineering Institute" (JSC "VTI") is used. One of the ways to increase the condenser efficiency has been proposed. It is the heat transfer augmentation with riffling annular grooves on tubes. This method increases the heat transfer coefficient by 2%, reduces the water subcooling of the heating steam by 0.9 °C, and decreases the cooling area by 2%.


2012 ◽  
Vol 501 ◽  
pp. 114-116
Author(s):  
Chuang Sheng Wang ◽  
Feng Bao Bai

This paper using synchronous rotor mixer, had researched the influence of preheating of raw rubber on the physical and mechanical properties of the tread under the same fill factor, rotor speed, cooling water temperature, and the pressure on top of bolt. According to processing and analysis of the experimental data, we can conclude that: As the temperature of raw rubber increased, the physical and mechanical properties of the tread had changed.


Author(s):  
Thomas J. Muldoon ◽  
Joseph A. Bruno

When the maximum temperature of cooling water slowly increases with temperature changes and shifting climate patterns, smaller LMTD’s (log mean temperature differences) for the CCW’s to meet the same performance heat rejection. Making the issue more critical is that the peak cooling water temperatures will usually occur at the same time as peak summer load demand. A smaller LMTD means a larger heat exchanger and more effective tubing surface area. More surface, means more tubing or smaller diameter tubing. If the original LMTD was 12 °F, a 1 degree change may mean an increase of 9%. To maintain the same nozzle locations on a replacement exchanger means a smaller tube outside diameter and/or a larger shell. Such increases are necessary for the high summer load conditions with the highest inlet water temperatures. At lower water temperatures, the amount of excess thermal capability can become a performance and corrosion issue as the water flows are modulated to meet temperatures. To help reduce these problems, a design which allows operation with reduced surface at low temperatures is appropriate. The temperature approach (Cooling Water Out – Service Water In) based on the higher inlet cooling water temperature can be significantly smaller than when the CCW was originally designed. This paper will address a design configuration that will work with both higher summer temperature cooling water with the flexibility of using less water for cooler winter operation. The overall affect is less pumping power during colder months, more consistent tube velocities which will help with heat transfer, and minimization of sediment settling in the tubes due to lower velocities.


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