Technoeconomic Optimization of Turbocompression Cooling Systems

2017 ◽  
Author(s):  
Spencer C. Gibson ◽  
Derek Young ◽  
Todd M. Bandhauer
Keyword(s):  
Heat Exchangers ◽  
Power Plants ◽  
High Efficiency ◽  
Waste Heat ◽  
Cooling System ◽  
Payback Period ◽  
Low Grade ◽  
Air Cooling ◽  
Total System ◽  
Cooling Systems

Low grade waste heat streams with temperatures near 100°C are abundant, presenting a significant opportunity to reduce primary energy consumption across the world. For example, thermally activated cooling systems can utilize waste heat to meet air conditioning loads. Recently, a turbocompression cooling system (TCCS) that utilizes low grade waste heat from power plants was investigated to improve the economic viability of dry air cooling systems. The TCCS utilizes Rankine and vapor-compression cycles that are directly coupled through a high efficiency centrifugal turbine and a compressor. In this paper, a coupled thermodynamic, heat transfer, and economic model for a TCCS is applied to utilizing low grade engine coolant waste heat to meet cargo ship cooling load requirements while minimizing the payback period for a particular operational scenario. The results of this study show that with a constant heat input of 2 MW, the liquid coupled turbocompression cooling system provided 642 kW of cooling with a payback period of 2 years and 6 months, and the total cost of the heat exchangers made up more than 84% of the total system cost. In addition, a sensitivity analysis showed that the effectiveness of the power cycle heat exchangers have a stronger influence on the payback period than the cooling cycle heat exchangers.

Dry Air Turbo-Compression Cooling

2016 ◽  
Author(s):  
Todd M. Bandhauer ◽  
Shane D. Garland
Keyword(s):  
Power Plant ◽  
Heat Exchangers ◽  
Power Plants ◽  
High Efficiency ◽  
Waste Heat ◽  
Evaporative Cooling ◽  
Low Grade ◽  
Air Cooling ◽  
Dry Air ◽  
Turbo Compressor

Electric power plants in the U.S. dissipate 4.3 billion gallons of water per day into the atmosphere through evaporative cooling. As freshwater resources become constrained, it will be essential for power plants to transition from evaporative cooling to dry air cooling. One of the major problems associated with dry air cooling is the large size and associated cost of the dry air heat exchangers due to the large surface area required to overcome the low convective heat transfer coefficient of air. This study investigates using low-grade waste heat available in the combustion exhaust gases (106°C inlet, 86 MW dry waste heat available) of a 565 MW Natural Gas Combined Cycle Power Plant (NGCC) to drive a supplemental high efficiency turbo-compression cooling (TCC) system that decreases the size of the dry air heat exchangers. In this system, both a recuperative Rankine cycle and a supercritical system were considered to drive a turbo-compressor. The low-grade waste heat is supplied to a flue gas heat exchanger in either the recuperative Rankine or supercritical cycle to generate power that drives a vapor compression cycle to supply supplementary cooling for the power plant condenser water. For the TCC system to operate at a high COP, both the turbine and compressor must operate at isentropic efficiencies exceeding 80%. This high efficiency has been demonstrated for centrifugal turbomachines for a wide variety of applications over small ranges of specific speed: from 45 to 100 for turbines, and from 80 to 140 for compressors. In the present study, a wide range of possible fluids was considered to perform a complete system level thermodynamic analysis combined with a turbo-compressor dimensional scaling analysis. The results of the analyses show that the total UA required for both the primary dry air coolers and the dry air condensers in the supercritical TCC system with a COP of 2 is 26% less than the UA required for dry air cooling alone (from 150.7 to 111.5 MW K−1). As a result, using the supercritical TCC cooling system has the potential to reduce the overall cost of dry air cooling relative to the state of the art.

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during the night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both cool thermal storage technologies considered perform similarly in terms of gross extra production of energy. Despite this, the ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of the plant site resulted in a greater increase in the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important the size of inlet cooling storage may be for economical results.

Performance Assessment of Steam Injection Gas Turbine With Inlet Air Cooling

1997 ◽  
Author(s):  
Carlo M. Bartolini ◽  
Danilo Salvi
Keyword(s):  
Ambient Temperature ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Heat Recovery ◽  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Steam Injection ◽  
Maximum Efficiency ◽  
Air Cooling

The steam generated through the use of waste heat recovered from a steam injection gas turbine generally exceeds the maximum mass of steam which can be injected into steam injection gas turbine. The ratio between the steam and air flowing into the engine is not more than 10–15%, as an increase in the pressure ratio can cause the compressor to stall. Naturally, the surplus steam can be utilized for a variety of alternative applications. During the warmer months, the ambient temperature increases and results in reduced thermal efficiency and electrical capacity. An inlet air cooling system for the compressor on a steam injection gas turbine would increase the rating and efficiency of power plants which use this type of equipment. In order to improve the performance of steam injection gas turbines, the authors investigated the option of cooling the intake air to the compressor by harnessing the thermal energy not used to produce the maximum quantity of steam that can be injected into the engine. This alternative use of waste energy makes it possible to reach maximum efficiency in terms of waste recovery. This study examined absorption refrigeration technology, which is one of the various systems adopted to increase efficiency and power rating. The system itself consists of a steam injection gas turbine and a heat recovery and absorption unit, while a computer model was utilized to evaluate the off design performance of the system. The input data required for the model were the following: an operating point, the turbine and compressor curves, the heat recovery and chiller specifications. The performance of an Allison 501 KH steam injection gas plant was analyzed by taking into consideration representative ambient temperature and humidity ranges, the optimal location of the chiller in light of all the factors involved, and which of three possible air cooling systems was the most economically suitable. In order to verify the technical feasibility of the hypothetical model, an economic study was performed on the costs for upgrading the existing steam injection gas cogeneration unit. The results indicate that the estimated pay back period for the project would be four years. In light of these findings, there are clear technical advantages to using gas turbine cogeneration with absorption air cooling in terms of investment.

Performance Evaluation of Multi-Stage Shell and Tube Transport Membrane Condenser Heat Exchangers for Low Grade Waste Heat and Water Recovery

2017 ◽  
Author(s):  
Soheil Soleimanikutanaei ◽  
Cheng-Xian Lin ◽  
Dexin Wang
Keyword(s):  
Water Vapor ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Power Plants ◽  
Ceramic Membrane ◽  
Waste Heat ◽  
Low Grade ◽  
Water Recovery ◽  
Multi Stage ◽  
Shell And Tube

In this work for the first time the performance of multi-stage shell and tube Transport Membrane Condenser (TMC) based heat exchangers are evaluated numerically. The present heat exchanger is design to work under high pressure and temperature condition for both heat and water recovery in Oxy-Combustion processes. TMC heat exchangers use the nano-porous and ceramic membrane technology to extract the water vapor and latent heat of condensation from the flue-gas. The most important application of TMC heat exchangers is in the power plants which the water vapor in the presence of other non-condensable gases (i.e. CO2, O2 and N2) exist. Effect of the different arrangement of the multi-stage shell and tube TMC heat exchangers, number of branches and number of heat exchangers in each branch on the heat transfer and water recovery have been studied numerically. A single phase multi-component model is used to assess the capability of single stage TMC heat exchangers in terms of waste heat and water recovery at various inlet conditions. Numerical simulation has been performed using ANSYS-FLUENT software and the condensation rate model has been implemented applying User Define Function. Finally, an optimum configuration for the TMC heat exchanger unit has been proposed and the results of numerical simulations are depicted in terms of temperature and water vapor mass fraction contours.

scholarly journals ОХОЛОДЖЕННЯ ПОВІТРЯ НА ВХОДІ ГОЛОВНОГО СУДНОВОГО ДВИГУНА АБСОРБЦІЙНОЮ БРОМИСТОЛІТІЄВОЮ ХОЛОДИЛЬНОЮ МАШИНОЮ В ТРОПІЧНИХ УМОВАХ

2020 ◽  
pp. 18-23
Author(s):  
Роман Миколайович Радченко ◽  
Дмитро Вікторович Коновалов ◽  
Максим Андрійович Пирисунько ◽  
Чжан Цян ◽  
Луо Зевей
Keyword(s):  
Air Temperature ◽  
High Efficiency ◽  
Waste Heat ◽  
Cooling System ◽  
Ambient Air ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Exhaust Gas ◽  
Low Speed ◽  
Speed Engine

The efficiency of air cooling at the inlet of the main low speed engine of a transport vessel during operation in tropical climatic conditions on the Shanghai-Karachi-Shanghai route was analyzed. The peculiarity of the tropical climate is the high relative humidity of the air at the same time its high temperatures, and hence the increased thermal load on the cooling system, which requires efficient transformation of the waste heat into the cold in the case of the use of waste heat recovery refrigeration machines. The cooling of the air at the inlet of the low speed engine by absorption lithium bromide chillers, which are characterized by high efficiency of transformation of waste heat into cold – by high coefficients of performance, is investigated. A schematic-construction solution of the air cooling system at the inlet of the ship's main engine using the heat of exhaust gases by an absorption chiller is proposed and analyzed. With this the cooling potential of the inlet air cooling from the current ambient air temperature to 15 ° C and the corresponding heat consumption for the operation of the adsorption chiller, on the one hand, was compared with the available exhaust gas heat potential, on the other hand. The effect of using the exhaust gas heat to cool the air at the inlet of the engine has been analyzed taking into account the changing climatic conditions during the voyage. Enhancement of fuel efficiency of the ship's engine by reducing the inlet air temperature were evaluated by current values of the reduction in specific and total fuel consumption. It is shown that due to the high efficiency of heat conversion in absorption chillers (high coefficients of performance 0.7…0.8), a significant amount of excessive exhaust gas heat over the heat required to cool the ambient air at the inlet of the engine to 15 ° C, which reaches almost half of the available exhaust gas heat during the Shanghai-Karachi-Shanghai route. This reveals the possibility of additional cooling a scavenge air too with almost double fuel economy due to the cooling of all cycle air of the low speed engine, including the air at the inlet.

Working Fluid Selection and Technoeconomic Optimization of a Turbocompression Cooling System

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
Derek Young ◽  
Spencer C. Gibson ◽  
Todd M. Bandhauer
Keyword(s):  
Heat Exchanger ◽  
Heat Recovery ◽  
Waste Heat Recovery ◽  
Waste Heat ◽  
Cooling System ◽  
Payback Period ◽  
Working Fluid ◽  
Low Grade ◽  
Diesel Generator ◽  
Working Fluids

Abstract Low grade waste heat recovery presents an opportunity to utilize typically wasted energy to reduce overall energy consumption and improve system efficiencies. In this work, the technoeconomic performance of a turbocompression cooling system (TCCS) driven by low grade waste heat in the engine coolant of a large marine diesel generator set is investigated. Five different working fluids were examined to better understand the effects of fluid characteristics on system performance: R134a, R245fa, R1234ze(E), R152a, and R600a. A coupled thermodynamic, heat exchanger, and economic simulation was developed to calculate the simple payback period of the waste heat recovery system, which was minimized using a search and find optimization routine with heat exchanger effectiveness as the optimization parameter. A sensitivity study was performed to understand which heat exchanger effectiveness had the largest impact on payback period. Of the five working fluids examined, a TCCS with R152a as the working fluid had the lowest payback period of 1.46 years with an initial investment of $181,846. The R152a system was most sensitive to the two-phase region of the power cycle condenser. The R1234ze(E) system provided the largest return on investment over a ten year lifetime of $1,399,666.

scholarly journals Improving the cooling system of ship equipment

2020 ◽  
Author(s):  
А.В. Фомин ◽  
Е.В. Фомин
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Cooling System ◽  
Heat Removal ◽  
Normal Operation ◽  
Water Cooling ◽  
Cooling Systems ◽  
Start Up ◽  
Membrane Type ◽  
Water Cooling System

В статье представлены результаты исследования эффективности работы системы охлаждения корабельного оборудования и предложены конструктивные решения, позволяющие модернизировать данную систему. В настоящее время, для обеспечения нормальной работы корабельного оборудования, применяются системы охлаждения. В корабельных энергетических установках распространены системы водяного охлаждения из-за целого ряда преимуществ. К ним относится и высокая эффективность теплоотвода, и меньшее влияние внешней среды, а также более надежный пуск и возможность использования энергии отводимого тепла для других нужд. Одним из основных элементов в таких системах является расширительный бак гравитационного типа, обеспечивающий правильную циркуляцию дистиллированной воды во внутреннем контуре и расположенный в верхней точке системы. Однако практика испытаний и эксплуатации показала, что есть и серьезный недостаток в таком расположении бака – в случаи его перелива или разрыва может пострадать дорогостоящее оборудование, расположенное ниже. В связи с этим, определены направления по совершенствованию системы водяного охлаждения корабельного оборудования, которые связаны с применением расширительного бака мембранного типа и использования воздухоудаляющих клапанов. The article presents the results of a study of the efficiency of the cooling system of ship equipment and offers design solutions that allow to modernize this system. Currently, to ensure the normal operation of ship's equipment, cooling systems are used. Water cooling systems are common in ship power plants due to a number of advantages. These include high efficiency of heat removal, less influence of the external environment, as well as more reliable start-up and the ability to use the energy of the heat being withdrawn for other needs. One of the main elements in such systems is a gravity-type expansion tank that ensures proper circulation of distilled water in the internal circuit and is located at the top of the system. However, the practice of testing and operation has shown that there is a serious drawback in this arrangement of the tank – in cases of overflow or rupture, expensive equipment located below may suffer. In this regard, the directions for improving the water cooling system of ship equipment, which are associated with the use of an expansion tank of the membrane type and the use of air-removing valves, have been identified.

An Estimation of the Performance Limits of Dry Cooling on Trough-Type Solar Thermal Plants

2008 ◽  
Author(s):  
Huifang Deng ◽  
Robert F. Boehm
Keyword(s):  
Power Plants ◽  
High Efficiency ◽  
Cooling System ◽  
Low Cost ◽  
Performance Limits ◽  
Cooling Systems ◽  
Solar Power Plants ◽  
Solar Resource ◽  
Dry Cooling ◽  
The Ideal

The southwestern US is an ideal location for solar power plants due to its abundant solar resource, while there is a difficulty in implementing wet cooling systems due to the shortage of water in this region. Dry cooling could be an excellent solution for this, if it could achieve a high efficiency and low cost as wet cooling. Some dry cooling systems are currently in operation, and investigations of their performance have been reported in the literature. This paper looks into the limits to the power production implicit in dry cooling, assuming that improvements might be made to the system components. Use of higher performance heat transfer surfaces is one such possible improvement. We have developed a model of a fairly typical, but simplified, solar trough plant, and simulated thermodynamic performance of this with the software Gatecycle. We have examined the power generation and cycle efficiency of the plant for the Las Vegas vicinity with conventional wet cooling and conventional dry cooling cases considered separately using this software. TMY2 data are used for this location for this purpose. Similarly, the same studies are carried out for “ideal” cooling systems as a comparison. We assumed that in the ideal dry cooling system, the condensing temperature is the ambient dry bulb temperature, and in the ideal wet cooling system, it is the ambient wet bulb temperature. It turned out that the ideal dry cooling system would significantly outperform the conventional wet cooling system, indicating the possibility of the dry cooling system being able to achieve increased performance levels with component improvements.

Inlet Air Cooling Applied to Combined Cycle Power Plants: Influence of Site Climate and Thermal Storage Systems

2007 ◽  
Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi
Keyword(s):  
Power Output ◽  
Parametric Analysis ◽  
Power Plants ◽  
Cooling System ◽  
Thermal Storage ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Air Cooling ◽  
Ambient Conditions ◽  
Cooling Systems

The paper presents the results of an investigation on inlet air cooling systems based on cool thermal storage, applied to combined cycle power plants. Such systems provide a significant increase of electric energy production in the peak hours; the charge of the cool thermal storage is performed instead during night time. The inlet air cooling system also allows the plant to reduce power output dependence on ambient conditions. A 127 MW combined cycle power plant operating in the Italian scenario is the object of this investigation. Two different technologies for cool thermal storage have been considered: ice harvester and stratified chilled water. To evaluate the performance of the combined cycle under different operating conditions, inlet cooling systems have been simulated with an in-house developed computational code. An economical analysis has been then performed. Different plant location sites have been considered, with the purpose to weigh up the influence of climatic conditions. Finally, a parametric analysis has been carried out in order to investigate how a variation of the thermal storage size affects the combined cycle performances and the investment profitability. It was found that both considered cool thermal storage technologies perform similarly in terms of gross extra-production of energy. Despite to that, ice harvester shows higher parasitic load due to chillers consumptions. Warmer climates of plant site resulted to increase more the amount of operational hours than power output augmentation; investment profitability is different as well. Results of parametric analysis showed how important may be, for economical results, the size of inlet cooling storage.

Thermo-Economic Analysis on Waste Heat and Water Recovery Systems of Boiler Exhaust in Coal-Fired Power Plants

2020 ◽  
Author(s):  
Kaixuan Yang ◽  
Ming Liu ◽  
Junjie Yan
Keyword(s):  
Power Plant ◽  
Heat Exchangers ◽  
Power Plants ◽  
Electrostatic Precipitator ◽  
Waste Heat ◽  
Recovery Period ◽  
Air Cooling ◽  
Water Recovery ◽  
Coal Consumption ◽  
Static Recovery

Abstract Waste heat and water recovery from boiler exhaust fluegas is significant for reducing coal and water consumption of coal-fired power plants. In this study, waste heat and water recovery system No.1 (WHWR1) and No.2 (WHWR2) were proposed with a 330MW air-cooling coal-fired power plant as the reference power plant. In these systems, boiler exhaust fluegas is cooled to 95 °C in fluegas coolers before being fed to the electrostatic precipitator. Moreover, a fluegas condenser is installed after the desulfurizer to recover water from fluegas. The recovered waste heat is used to heat the condensation water of the regenerative system, boiler feeding air and the fluegas after fluegas condenser. Then, thermodynamic and economic analyses were carried out. Heat exchangers’ areas of WHWRs are affected by heat loads and heat transfer temperature differences. For the unit area cost of heat exchangers is different, the cost of WHWRs may be decreased by optimizing multiple thermodynamic parameters of WHWR. Therefore, the optimization models based on Genetic Algorithm were developed to obtain the optimal system parameters with best economic performance. Results show that the change in coal consumption rate (Δb) is ∼ 4.8 g kW−1 h−1 in WHWR2 and ∼ 2.9 g kW−1 h−1 in WHWR1. About 15.3 kg s−1 of water can be saved and recovered when the fluegas moisture content is reduced to 8.5%. The investment of WHWR2 is higher than WHWR1, while the static recovery period of WHWR2 is shorter than that of WHWR1 for the additional Δb of pre air pre-heater.

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