Processing Techniques of a Silicon Carbide Heat Exchanger and its Capable Properties – A Review

2015 ◽  
Vol 787 ◽  
pp. 513-517 ◽  
Author(s):  
R. Pachaiyappan ◽  
R. Gopinath ◽  
S. Gopalakannan
Keyword(s):  
Silicon Carbide ◽  
Heat Exchanger ◽  
Gas Turbines ◽  
Cooling System ◽  
Composite Ceramic ◽  
Processing Technique ◽  
Full Potential ◽  
Absorption Chillers ◽  
Evaporative Cooling System ◽  
Processing Techniques

Silicon carbides is a composite ceramic material produced from inorganic non-metallic substances, formed from the molten mass which solidifies on cooling and simultaneously matured by the action of heat. It is used in various applications such as grinding wheels, filtration of gases and water, absorption, catalyst supports, concentrated solar powers, thermoelectric conversion etc. The modern usage of silicon carbide is fabricated as a heat exchanger for high temperature applications. Leaving behind steel and aluminium, silicon carbide has an excellent temperature withstanding capability of 1425°C. It is resistant to corrosion and chemical erosion. Modern fusion reactors, Stirling cycle based gas turbines, evaporators in evaporative cooling system for air condition and generator in LiBr/H2O absorption chillers for air conditioning those systems heat transfer rate can be improved by replacing a present heat exchanger with silicon carbide heat exchanger. This review presents a detailed discussion about processing technique of such a silicon carbide. Modern known processing techniques are partial sintering, direct foaming, replica, sacrificial template and bonding techniques. The full potential of these materials can be achieved when properties are directed over specified application. While eyeing over full potential it is highly dependent on processing techniques.

scholarly journals The Effect of Dry and Wet Bulb Temperature Variation on the Performance of the Indirect Evaporative Cooler

2019 ◽  
Vol 26 (4) ◽  
pp. 8-15
Author(s):  
Maki Zaidan ◽  
Fayadh Abed ◽  
Ali Farhad
Keyword(s):  
Heat Exchanger ◽  
Environmental Changes ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Computer Software ◽  
Volumetric Flow Rate ◽  
Weather Conditions ◽  
Centrifugal Fan ◽  
Pipe Length ◽  
Evaporative Cooling System

The research is about designing and building up an evaporative cooling system, working by two- stages evaporative cooling system using outer air (pure air). The system is founded by designing and making a heat exchanger of orthogonal flow from Aluminum sheets of (30*60*40) cm, which represents the first stage of the system (indirect stage). The second stage (direct stage) of the system is represented by making an equipment of air washing (cylindrical) with (45 height, 60 width, 3 thickness) cm. The cooling system pulls outer air by a Centrifugal fan. The air passes through the heat exchanger pipes to be cooled tangibly (without moistening). Then it goes over the equipment of air washing to be cooled and cools the specified space. Computer software was designed by FORTRAN Language (FORTRAN 90) to predict the evaporative air cooler performance to know the proper environmental and design conditions of the system. Some variables were made to study their effect on the thermal performance of the system. The studied variable is to change the volumetric flow rate of air from (750 cfm) to (2000 cfm) of the dry side, and from (750 cfm) to (2500 cfm) of the wet side. The pipe length was changed from (20 cm) to (45 cm), and its diameter from (0.5 cm) to (3 cm). Those were the design changes. On the environmental changes, we studied the effect of changing the temperature on the dry or wet bulb of the system. The study is taken place in Tikrit University (34. 35N; 43.37 E), to determine the suitability of the weather conditions of the region for the work of the system. It was taken place in the late August for two consecutive days, with readings of 24 hours. The results show that the best quantity of the air supplied, which represent the best performance of the system (750 cfm) and (1000 cfm) for the wet side when the diameter (1-1.5 cm) and length is (45 cm). The results show also the possibility of the work of this system for the region mentioned because it is characterized by its hot and dry climate in the summer, as the efficiency of evaporative evaporator increases the hot and dry environment by 80%.

Gas Turbine Direct Exhaust Gas Integration in Process Industry: Applications Review

2020 ◽  
Author(s):  
Marek Cichocki ◽  
Ilona Salamonik ◽  
Marcin Bielecki ◽  
Ever Fadlun ◽  
Artur Rusowicz
Keyword(s):  
Energy Consumption ◽  
Specific Energy ◽  
Gas Turbines ◽  
Cooling System ◽  
Specific Energy Consumption ◽  
Process Industry ◽  
Reference List ◽  
Exhaust Gas ◽  
Exhaust Gases ◽  
Absorption Chillers

Abstract The typical combined heat and power plants requires the introduction of additional heating medium. The alternative solution is the direct integration of the exhaust gases from heat engine. High temperature, surplus oxygen and low water content of the Gas Turbines exhaust gases enabled the successful integration at industrial scale as: preheated combustion air for industrial furnaces, heat source for drying and for absorption chillers. The article comprises the reference list for direct exhaust gas integration of GTs produced by Baker Hughes formerly GE), the processes overview, GTs selection criteria, as well as the review of documented GTs applications in process industry focusing on technical and economic considerations. Majority of referenced applications for industrial furnace are in the steam methane reformers used in fertilizer industry, as well as steam crackers in petrochemical industries. Several GTs were integrated with crude oil furnace in refinery. Direct drying utilizing exhaust gas from GT, is commonly applied in ceramic, wood derivative, pulp & paper and inorganic chemicals industries. Integrating GTs with absorption chillers was introduced to serve the district heating and cooling system. The described solutions allowed to reduce specific energy consumption by 7–20% or the costs of energy consumption associated with large volume production by 15–30%. The reduction of specific energy consumption allows to decrease the amount of CO2 emitted. The overall efficiency of cogeneration plant above 90% was achieved.

Experience With a Fast Track Power Generation Project

2000 ◽  
Author(s):  
Albrecht H. Mayer ◽  
Noel W. Lively
Keyword(s):  
System Performance ◽  
Gas Turbines ◽  
Fast Track ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Combined Cycle ◽  
Plant Design ◽  
Engineering Construction ◽  
Reference Plant ◽  
Evaporative Cooling System

To meet peaking power demands the E.W. Brown Station, owned and operated by Kentucky Utilities Company, was extended by two GT24 gas turbines. The project had to meet a 9-month engineering, construction and commissioning schedule. The conceptual design is based on ABB ALSTOM POWER’S reference plant design for combined cycle application. It was adjusted to the requirements of a simple cycle operation. Special plant features such as evaporative cooling of the inlet air, system design of the evaporative cooling system, performance and experience will be discussed in detail. The plant has an aggressive running and starting reliability goal; the approach to meet the required plant reliability will be discussed below. The initial operational feedback will be addressed as well as an outlook on how to meet all project goals.

scholarly journals Field Experiments and Technical Evaluation of an Optimized Media Evaporative Cooler for Gas Turbine Power Augmentation

2012 ◽  
Vol 10 (3) ◽  
Author(s):  
A. Behdashti ◽  
M. Ebrahimpour ◽  
B. Vahidi ◽  
V. Omidipour ◽  
A. Alizadeh
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Field Experiments ◽  
Cooling System ◽  
Cooling Capacity ◽  
Combined Cycle ◽  
Air Cooling ◽  
Humidity Effect ◽  
Media Type ◽  
Evaporative Cooling System

This paper discusses an optimized media type evaporative cooling system called Outdoor Movable Media cooler which has been recently implemented on two 160 MW, V94.2 gas turbines of Kerman combined cycle power plant, Iran. The air cooling system can be applied to retrieve the lost power generation capability of gas turbine during hot months. System description is completely presented and optimizations such as making a movable media cooler are described. The moving ability of this system eliminates the power loss related to the conventional media coolers. Furthermore, experimental work including evaluation of humidity effect on the air filters operation is discussed and the results are presented. The cooling system performance curve shows the system capability of cooling the inlet air up to 19°C at the design condition. This cooling capacity leads to power augmentation up to 14% which is noteworthy in responding to the electricity demand in hot months, when air-conditioning loads are maximized. Considering several parameters, a cost analysis is done finally and payback period of the system is calculated.

Solar-Assisted Liquid Desiccant Dehumidification Using Hollow-Fiber and Parallel-Plate Membrane Dehumidifiers: Comparative Analysis

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Haitham M. Bahaidaraha ◽  
Mohand H. Mohamed ◽  
Esmail M. A. Mokheimer
Keyword(s):  
Heat Exchanger ◽  
Latent Heat ◽  
Hollow Fiber ◽  
Parallel Plate ◽  
Cooling System ◽  
Thermal Capacity ◽  
Air Conditioner ◽  
Liquid Desiccant ◽  
Evaporative Cooling System ◽  
Mass Exchanger

In hot and humid climates, air conditioning is an energy-intensive process due to the latent heat load. A unitary air conditioner system is proposed, here, to reduce the latent heat of the humid air using a liquid desiccant followed by an evaporative cooling system. The heat liberated by the desiccant is removed by a solution to the solution heat exchanger. To restore the concentration of the liquid desiccant, the desiccant solution is regenerated by any low-temperature heat source such as solar energy. In order to make the system compact, the membrane heat exchanger is used for the dehumidifier and regenerator. This paper presents the numerical investigation of heat and mass transfer characteristics of a selected membrane dehumidifier under different climatic parameters. Membrane-based parallel-plate and hollow-fiber exchangers are used for this application. A parallel-plate heat-and-mass exchanger (contactor) is composed of a series of plate-type membrane sheets to form channels. On the other hand, hollow-fiber membranes are packed in a shell to form a shell-and-tube heat-and-mass exchanger. The two streams of both contactors are in a counter parallel flow, separated by micro-porous semi-permeable hydrophobic membranes. In this research, the equations governing the transport of heat and mass between the two streams along with the membrane effect in both contactors are solved numerically. The results are compared at different number-of-transfer units (NTU) on the airside and thermal capacity ratios. It is found that the hollow fiber is more efficient than the parallel plate.

Development of an Improved Desiccant-Based Evaporative Cooling System for Gas Turbines

2008 ◽  
Author(s):  
Amir Abbas Zadpoor ◽  
Ali Asadi Nikooyan
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Cooling System ◽  
Evaporative Cooling ◽  
Climatic Conditions ◽  
Cooling Systems ◽  
Actual Performance ◽  
Evaporative Cooling System ◽  
Industrial Gas Turbine ◽  
Gas Turbine Cycle

The evaporative inlet cooling systems used for inlet cooling of gas turbines during hot summers do not work well in humid areas. However, desiccant wheels can be used to dehumidify the air before passing it trough the evaporative cooler. Since the desiccant wheels work adiabatically, the resulting air is hotter than the air introduced to the wheel and an evaporative cooling system is used to cool down the dehumidified air. Combined direct and indirect evaporative coolers have been already used to investigate the effects of dehumidification on the effectiveness of the evaporation cooling systems. It is shown that a single desiccant wheel does not offer much higher effectiveness compared to the multiple-stage evaporative systems. In this paper, an improved version of the desiccant inlet cooling system is presented. Additional dehumidification and indirect evaporative cooling stages are added to increase the effectiveness of the inlet cooling. A typical gas turbine cycle along with an industrial gas turbine with actual performance curves are used to simulate the thermal cycle in presence of the different inlet cooling systems. The simulations are carried out for three different climatic conditions. The improved and original desiccant-based systems are compared and it is shown that the added stages substantially improve the effectiveness of the desiccant-based inlet cooling.

scholarly journals Analysis of Solar District Cooling systems: the Effect of Heat Rejection

2020 ◽  
Vol 197 ◽  
pp. 08018
Author(s):  
Giovanni Brumana ◽  
Giuseppe Franchini ◽  
Elisa Ghirardi ◽  
Antonio Perdichizzi
Keyword(s):  
Heat Exchanger ◽  
Cooling System ◽  
Optimization Procedure ◽  
Abu Dhabi ◽  
Air Cooling ◽  
Gulf Region ◽  
Cooling Systems ◽  
Heat Rejection ◽  
Absorption Chillers ◽  
Water Pipeline

The paper presents the performance assessment of a solar district cooling system with special attention to the heat rejection process. The investigation includes energetic, economic and environmental aspects. The district cooling network is driven by two-stage Li-Br absorption chillers coupled with parabolic trough solar collectors. The whole system, including solar field, storage tanks and chilled water pipeline, has been modelled in Trnsys. The focus is on the heat rejection systems, and their impact on the performance of the cooling plant. Four different types of heat rejection systems are considered: Air Cooling (AC), Evaporative Cooling Tower (ECT), Groundwater Heat Exchanger (GHE) and Geothermal Boreholes (GB). The paper presents two case studies in the Gulf region: the warm climate is compared for two condition of humidity, dry (Riyadh) and humid (Abu Dhabi). Furthermore, the work presents a multivariable optimization procedure based on GenOpt software interacting with Trnsys model under the constraint of a 70% annual solar fraction. The best option resulted to be the one based on absorption chillers coupled with Groundwater Heat Exchanger in both locations. The annual power consumption is reduced by 83% in Abu Dhabi and 82% in Riyadh compared to conventional cooling systems.

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