A shortcut method for simultaneous energy and heat exchange area optimization with variable stream conditions

2020 ◽  
Vol 175 ◽  
pp. 115363
Author(s):  
Matteo Cassanello ◽  
Yingzong Liang ◽  
Chi Wai Hui
Keyword(s):  
Heat Exchange ◽  
Exchange Area ◽  
Area Optimization ◽  
Shortcut Method

Concurrent Reduction of Draft Height and Heat-Exchange Area for Large Dry Cooling Towers

1974 ◽  
Vol 96 (3) ◽  
pp. 279-285 ◽  
Author(s):  
F. K. Moore ◽  
T. Hsieh
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Full Description ◽  
Large Power ◽  
Water Pumping ◽  
Exchange Area ◽  
Fold Reduction ◽  
Water Side ◽  
Dry Cooling Tower ◽  
Dry Cooling

A procedure is outlined to meet simultaneous requirements to reduce overall size of a dry cooling tower for a large power plant, and to reduce the size (surface area) of the associated air-water heat exchanger. First, tower exit dimensions (or fan power) are specified as attainable fractions of their theoretical minima as found from a draft equation. Then a heat-exchanger type is chosen, having as small an air hydraulic diameter as feasible. Appropriate equations and assumptions dealing with air side and water side heat exchange and water pumping power then yield a full description of tower and heat-exchanger characteristics for a given tower duty. A specific example is worked out and compared with the tower at Rugeley, England. We find that a very open heat exchanger, of shallow depth (one in or less) results from our analysis, and in a proposed configuration of acceptable header loss gives a 1/3 height reduction and a four-fold reduction of heat-exchanger area.

scholarly journals MULTI-FACTOR HEAT EXCHANGER DESIGN MODELS

2021 ◽  
Vol 2 (37) ◽  
pp. 49-54
Author(s):  
R. Klimov ◽  
E. Lusta
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Regression Equations ◽  
Simple Formulation ◽  
Finned Tubes ◽  
Heat Exchanger Design ◽  
Exchange Area ◽  
Compactness Factor ◽  
Shell And Tube ◽  
Fisher’S Criterion

Compressed air is widely used in enterprises, and it is possible to reduce air consumption on pneumatic devices by heating. Most often, heating is carried out in shell-and-tube heat exchangers. To increase the area of heat exchange between the heating medium and the air, finned tubes are used, which can significantly reduce the volume occupied by the heater. The design of the heater is influenced by many factors, and the importance of the influence of each of them can differ significantly. It is advisable to use the overall characteristic in the form of a compactness factor, which shows the ratio of the heat exchange area to the volume of the heater. The work developed a method for determining the optimal design of heaters by such a parameter as the compactness factor. The obtained regression equations make it possible to determine the influence of such factors as the number of rows of tubes across the flow and the length of one tube on the volume occupied by the heat exchanger and the compactness factor. According to Fisher's criterion, the equations of the model are adequate to the true dependence with a confidence level of 95%. Most of all, the volume of the heat exchanger and the compactness are affected by the number of tubes transverse to the air flow. Changing the length of one tube does not fundamentally affect the obtained values of the output parameters. With an increase in the length of one tube and their number across the flow, it is possible to achieve the highest values of the compactness coefficient, the dependence of which on the main factors has a pronounced maximum. Using the developed technique, it is possible, in a fairly simple formulation, to analyze the value of the compactness factor for various combinations of the above factors and to optimize the design of the heater.

Mechanism of the heat exchange promotion by superimposing the external sound wave in standing-wave thermoacoustic system

2021 ◽  
Author(s):  
Koto Hiramatsu ◽  
Shin-ichi SAKAMOTO ◽  
Yoshiaki Watanabe
Keyword(s):  
Boundary Layer ◽  
Heat Exchange ◽  
Sound Wave ◽  
Energy Conversion Efficiency ◽  
Work Flow ◽  
Working Fluid ◽  
Particle Displacement ◽  
View Point ◽  
Exchange Area ◽  
Flow Generation

Abstract For improvement of energy conversion efficiency, sound wave is superimposed with a loudspeaker to the working fluid in the stack. By using this method the work-flow generation of the stack was enhanced. To analyze this enhancement mechanism, the thickness of the boundary layer and the heat exchange area in the stack are calculated from the view point of heat exchange circumstance. The effect of the heat exchange circumstance on the particle displacement and heat flow is investigated. As a result, it is confirmed that the superimposed sound wave improves the heat exchange circumstance and then the thermoacoustic phenomenon is enhanced.

Selection of organic Rankine cycle working fluid based on unit-heat-exchange-area net power

2015 ◽  
Vol 22 (4) ◽  
pp. 1548-1553
Author(s):  
Mei-ru Guo ◽  
Qi-di Zhu ◽  
Zhi-qiang Sun ◽  
Tian Zhou ◽  
Jie-min Zhou
Keyword(s):  
Heat Exchange ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Working Fluid ◽  
Exchange Area ◽  
Selection Of

Synthesis Method of Heat Exchanger Network for Distillation Device

2011 ◽  
Vol 199-200 ◽  
pp. 1509-1512
Author(s):  
Yu Lin Ge ◽  
Ping Wang ◽  
Sheng Qiang Shen ◽  
Jun Liang Xu
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Heat Exchangers ◽  
Heat Load ◽  
Programming Model ◽  
Synthesis Method ◽  
Total Heat ◽  
Heat Exchanger Network ◽  
Exchange Area ◽  
Heat Exchange Network

Mathematical programming model for synthesis of heat exchanger network for distillation unit is established. MINLP problem for heat exchanger network is solved by branch-bound method. Two kinds of heat exchanger network with splitting stream and without splitting stream are obtained. 142 heat exchangers, 8 coolers and 4 heaters are needed in the heat exchanger network without splitting stream. 34 heat exchangers, 8 coolers, 4 heaters, 11 splitters and 11 mixers are needed in the heat exchanger network with splitting stream. The matching situation including heat load, heat exchange area, duty of utilities, flow fraction of splitting, temperature of inlet and outlet, etc. for cold and hot streams in the heat exchanger network with splitting stream is presented in detail, Analysis the relationship between total heat exchange area, total heat load, total capital cost and annual operation cost of the heat exchanger network. Taking the number of heat exchangers and operational flexibility of heat exchange network into consideration, the heat exchanger network with splitting stream is suggested to be selected.

The Simulation and Experimental Research on Gas Cooler of the CO2 Trans-Critical Cycle

2011 ◽  
Vol 311-313 ◽  
pp. 1485-1490
Author(s):  
Kai Yang Wang ◽  
Yi Tai Ma ◽  
Qiu Xia Yuan
Keyword(s):  
High Pressure ◽  
Heat Exchange ◽  
Theoretical Model ◽  
Experimental Research ◽  
Cooling Water ◽  
Distributed Parameter ◽  
Maximum Deviation ◽  
Parameter Method ◽  
Inlet Temperature ◽  
Exchange Area

According to the character of the trans-critical CO2cycle, this paper develops the theoretical model of the gas cooler using the distributed-parameter method. At last, it optimizes the gas cooler. The comparison between the simulation and the experiments indicates: under different inlet temperature of cooling water, high pressure and mass flux of the refrigerant, the maximum deviation between the simulation and the experimental results is 5.6%, 10.1% and 19.7%,respectively. The optimal results indicates: when the refrigerant inlet is 8MPa and 93°C，and the cooling water inlet is 15°C，it is propitious to the inner heat exchange of the gas cooler using the four pipes of φ6mm×1mm, and the total heat exchange area of 1.1 m2.

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