Effect of Cooling Mode on Properties of a Cast Zinc Alloy

2013 ◽  
Vol 690-693 ◽  
pp. 66-69 ◽  
Author(s):  
Fei Zhang ◽  
Jin Gui Wan
Keyword(s):  
Material Properties ◽  
Cooling Water ◽  
Zinc Alloy ◽  
Air Cooling ◽  
Water Cooling ◽  
Cooling Mode ◽  
Comprehensive Properties ◽  
Alloy Material

In order to explore the best way of zinc alloy cooling, respectively adopting air cooling, water cooling, oil cooling and cooling in the furnace, to study its influence on the zinc alloy material properties. The results show that the oil cooling mode can improve the comprehensive properties of zinc alloy.

Design of Cooling Water Scheme of Gas Compressing Station in West-to-East Gas Pipeline

2014 ◽  
Vol 577 ◽  
pp. 580-583
Author(s):  
Hong Tao Li ◽  
Zhan Qiang Xu ◽  
Ben Rui Zhu
Keyword(s):  
Frequency Conversion ◽  
High Efficiency ◽  
Selection Process ◽  
Cooling Water ◽  
Economic Benefits ◽  
Gas Pipeline ◽  
Air Cooling ◽  
Water Cooling ◽  
Long Distance ◽  
First Choice

This document focuses on motors and frequency conversion equipments of stations of West-to-East Gas Pipeline, and introduces the present main cooling ways. Against water consumption, power consumption, and other economical index, analyze the selection process of cooling scheme in engineering design. Compare with the cost, workload of operation and maintenance of water cooling, air cooling and motor cooling. The result shows that water cooling is practicable in West-to-East Gas Pipeline and has validated in the established engineering. The method of scheme comparison proposed by this paper provides a reference for subsequent design.With the development of electronics technology, medium voltage high power frequency conversion speed regulation technology is increasingly mature. The technology that frequency conversion motor drives compressor unit has been gradually used in the long distance pipeline pressure field of oil and gas under the condition of reliable power supply, to replace the traditional gas turbine, and becomes the first choice of the pressurization equipment of the long distance pipeline, because of advantages of high technology, high efficiency, energy conservation and environment protection, economic benefits and so on[1-3].Stations of West-to-East Gas Pipeline are usually electrical driven. When the compressors operate, motors and frequency converters will produce large amounts of heat, which affects running state and equipment life. So choosing the economic and technological cooling water scheme is important for stations and the whole network to operate safely and stably[4-6].

Application of L-SIP to Pressurizer Nozzles

2011 ◽  
Author(s):  
Masaru Watanabe ◽  
Takeshi Ueda ◽  
Koji Okimura ◽  
Kazuhiro Wakabayashi ◽  
Takashi Akaba ◽  
...  
Keyword(s):  
Residual Stress ◽  
Air Cooling ◽  
Water Cooling ◽  
Surface Cooling ◽  
Power Laser ◽  
Cooling Mode ◽  
Steel Pipes ◽  
Inner Surface ◽  
The World ◽  
First Time

It has long been known that the most effective in a countermeasure for stress corrosion cracking in pipe and nozzle welds is by reducing the residual stress in the portion of the weld exposed to the corrosive environment. An irradiated laser stress improvement process (L-SIP) was introduced as a method to improve residual stress inside steel pipes and nozzles. L-SIP has been applied to the pressurizer nozzles in actual plant, Tsuruga unit 2 Japan, for the first time in the world. The nozzles to which this process was applied are the surge nozzle (September 2007), safety nozzles, relief nozzle and spray line nozzle (April 2010). L-SIP can be applied without inner surface cooling because the high power laser beam can generate the sufficient temperature difference without such cooling. Where necessary to achieve optimum temperarure difference, water cooling may also be applied at the inner surface. At Tsuruga unit 2, L-SIP was successfully applied to the spray line nozzle in air-cooling mode, and the surge nozzles, 3 safety nozzles and relief nozzle in water-cooling mode.

scholarly journals The Effect of the Cooling Process on the Crystalline Morphology and Dielectric Properties of Polythene

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2791
Author(s):  
Guang Yu ◽  
Boyang Yu
Keyword(s):  
Space Charge ◽  
Cooling Water ◽  
Dielectric Constants ◽  
Air Cooling ◽  
Water Cooling ◽  
Crystalline Morphology ◽  
Cooling Process ◽  
Experimental Frequency ◽  
Frequency Spectra ◽  
Two Samples

In this study, LDPE samples were prepared by melt blending with different cooling processes, which were natural air cooling, rapid air cooling, water cooling and oil cooling, respectively. According to polarization microscope (PLM) and differential scanning calorimeter (DSC) tests of these four low-density polyethylene (LDPE) samples, the effect of different cooling processes on polythene crystalline morphology could be studied. According to conductivity, dielectric frequency spectra and space charge tests, the effect of crystalline morphology on dielectric macroscopic properties could be explored. The microstructure characteristic results indicated the cooling medium significantly affected polythene crystalline morphology. When the samples were produced with natural air cooling, the crystalline grain size was large. On the other hand, after rapid air cooling, water cooling and oil cooling processes, the samples’ crystalline grain dispersed uniformly, and the grain sizes were lower. The space charge testing results indicate the samples produced with water cooling and oil cooling processes restrained the electrode injection in the process of pressurization. During short-circuits, the rates of charge release of these two samples were fast, and the remaining space charges were fewer. The conductivity and dielectric frequency spectra testing results indicated the conductivities of samples produced with water cooling and oil cooling processes were both less than those of samples produced with a natural air cooling process. Besides, with increasing experimental frequency, the relative dielectric constants of all testing samples decreased. Among them, the relative dielectric constant of the LDPE sample with the natural air cooling process was the largest. However, the crystalline structures of samples produced with rapid air cooling and water cooling processes were close, which restrained the movement of polymer macromolecule chains. Thus, the dielectric constants were lower. Additionally, because of the influence of relaxation polarization and dipole polarization, the dielectric losses of LDPE with water cooling and oil cooling processes increased to varying degrees.

High Performance Loop Heat Pipe With Flat Evaporator for Energy-Saving Cooling Systems of Supercomputers

2020 ◽  
Vol 142 (3) ◽  
Author(s):  
Zhi Hu Xue ◽  
Wei Qu ◽  
Ming Hui Xie
Keyword(s):  
Heat Load ◽  
High Performance ◽  
Operating Temperature ◽  
Cooling Water ◽  
Working Fluid ◽  
Air Cooling ◽  
Water Cooling ◽  
Test Results ◽  
Central Processing ◽  
Flat Evaporator

Abstract Two high performance loop heat pipes (LHPs) are developed for direct cooling of the chips in supercomputer. The two LHPs using flat evaporator are: one called water-cooling LHP and another one called air-cooling LHP. The working fluid of LHP is ammonia. The water-cooling LHP can work well at a heat load up to 663 W and air-cooling LHP can work well at a heat load up to 513 W. The two LHPs applying to the real computer servers are realized and tested. The server test results with water-cooling LHP have shown that the operating temperature of central processing units (CPUs) can be controlled to about 67 °C to ensure the reliable operating and acceptable level for electronic chips, even at condenser-cooling water temperature of 40 °C with low water flowrate of 0.055 m3/h. The server test results with air-cooling LHP have shown that the operating temperature of CPUs can be controlled to about 51 °C even at condenser-cooling wind temperature of 30 °C with wind flowrate of 41.88 m3/h.

scholarly journals Optimization of Cascade Cooling System Based on Lithium Bromide Refrigeration in the Polysilicon Industry

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1681
Author(s):  
Shutong Yang ◽  
Youlei Wang ◽  
Yufei Wang
Keyword(s):  
Annual Cost ◽  
Load Distribution ◽  
Heat Load ◽  
Waste Heat ◽  
Cooling System ◽  
Cooling Water ◽  
Total Annual Cost ◽  
Air Cooling ◽  
Water Cooling ◽  
Cooling Methods

Cascade cooling systems containing different cooling methods (e.g., air cooling, water cooling, refrigerating) are used to satisfy the cooling process of hot streams with large temperature spans. An effective cooling system can significantly save energy and costs. In a cascade cooling system, the heat load distribution between different cooling methods has great impacts on the capital cost and operation cost of the system, but the relative optimization method is not well established. In this work, a cascade cooling system containing waste heat recovery, air cooling, water cooling, absorption refrigeration, and compression refrigeration is proposed. The objective is to find the optimal heat load distribution between different cooling methods with the minimum total annual cost. Aspen Plus and MATLAB were combined to solve the established mathematical optimization model, and the genetic algorithm (GA) in MATLAB was adopted to solve the model. A case study in a polysilicon enterprise was used to illustrate the feasibility and economy of the cascade cooling system. Compared to the base case, which only includes air cooling, water cooling, and compression refrigeration, the cascade cooling system can reduce the total annual cost by USD 931,025·y−1 and save 7,800,820 kWh of electricity per year. It also can recover 3139 kW of low-grade waste heat, and generate and replace a cooling capacity of 2404 kW.

scholarly journals Effects of deformation on the microstructure of a Ti-V microalloyed steel in the phase transition region

2004 ◽  
Vol 57 (4) ◽  
pp. 303-311
Author(s):  
Wiliam Regone ◽  
Sérgio Tonini Button
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
Transition Region ◽  
Microstructural Evolution ◽  
Microalloyed Steel ◽  
Hot Forging ◽  
Microalloyed Steels ◽  
Air Cooling ◽  
Water Cooling ◽  
Phase Transition Region

Microalloyed steels are used in the forging of many automotive parts like crankshafts and connecting rods. They are hot worked in a sequence of stages that includes the heating to the soaking temperature, followed by forging steps, and finally the controlled cooling to define the microstructure and mechanical properties. In this work it was investigated the thermomechanical behavior and the microstructural evolution of a Ti-V microalloyed steel in the phase transition region. Torsion tests were done with multiple steps with true strain equal to 0.26 in each step. After each torsion step the samples were continuous cooled for 15 seconds to simulate hot forging conditions. These tests provided results for the temperature at the beginning of the phase transformation, and allowed to analyze the microstructural changes. Also, workability tests were held to analyze the microstructural evolution by optical and scanning electron microscopy. Results from the torsion tests showed that the temperature for the beginning of phase transformation is about 700 ºC. Workability tests held at 700 ºC followed by water-cooling presented microstructures with different regions: strain hardened, and static and dynamic recrystallized. Workability tests at 700 ºC followed by air-cooling showed a complex microstructure with ferrite, bainite and martensite, while tests at 650 and 600 ºC followed by water-cooling showed a microstructure with allotriomorphic ferrite present in the grain boundaries of the previous austenite.

Numerical Simulation of Intermediate Cooling Temperature Field in Controlled Rolling

2010 ◽  
Vol 148-149 ◽  
pp. 359-362
Author(s):  
Wen Feng Huo ◽  
Xian Lei Hu ◽  
Bing Xing Wang ◽  
Xiang Hua Liu
Keyword(s):  
Cooling Rate ◽  
Controlled Rolling ◽  
Holding Time ◽  
Air Cooling ◽  
Thickness Direction ◽  
Cooling Mode ◽  
Cooling Strategy ◽  
Profile Characteristics ◽  
Intermediate Cooling ◽  
Rolling Efficiency

Air cooling may decrease rolling efficiency in controlled rolling for needing long holding time to obtain the correct rolling temperature because of small cooling rate. The intermediate cooling can increate the cooling rate, and improve rolling efficiency. Experiment was carried out to research the effect of intermediate cooling on rolling efficiency. The influence of different cooling mode on the temperature distribution and the temperature profile characteristics of different cooling strategy are analyzed with FEM. It shows that intermediate cooling can decrease the holding time effectively, and improve rolling efficiency; the temperature homogeneity in thickness direction can be improved by opening the header one after another and cooling the plate by oscillating cooling.

A COMPARATIVE STUDY OF LARGE HYDRAULIC GENERATORS WITH AIR-COOLING AND WATER-COOLING

1993 ◽  
Vol 21 (5) ◽  
pp. 605-613
Author(s):  
LIN XIANSHU ◽  
GAO JINLING ◽  
YU GUOQIN
Keyword(s):  
Comparative Study ◽  
Air Cooling ◽  
Water Cooling

Residual Stress Analysis Considering Phase Transformation and Transformation Plasticity for Heat-Treated Large Size Shaft

2016 ◽  
Vol 725 ◽  
pp. 647-652 ◽  
Author(s):  
Yusuke Yanagisawa ◽  
Yasuhiro Kishi ◽  
Katsuhiko Sasaki
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Phase Transformation ◽  
Air Cooling ◽  
Water Cooling ◽  
Stress Distributions ◽  
Transformation Plasticity ◽  
Large Size ◽  
Heat Treated ◽  
Good Agreement

The residual stress distributions of the forgings after both water-cooling and air-cooling were measured experimentally. The residual stress occurring during the heat-treatment was also simulated considering the phase transformation and the transformation plasticity. A comparison of the experiments with the simulations showed a good agreement. These results shows that the transformation plastic strain plays an important role in the heat treatment of large forged shafts.

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