The Oriented Spray Cooling System for Supplementing Cooling Lakes

2017 ◽  
Author(s):  
Charles F. Bowman
Keyword(s):  
Power Plants ◽  
Waste Heat ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Spray Cooling ◽  
Cooling Capacity ◽  
Ambient Temperatures ◽  
Circulating Water ◽  
Auxiliary Power

With ever-increasing ambient temperatures many electric power plants that employ cooling lakes to reject their waste heat into the environment are struggling to maintain reasonable turbine backpressures during the hot summer months when electric load demand is often the greatest. Some consider adding mechanical draft cooling towers (MDCT) to further cool the condenser circulating water (CCW) prior to entering the main condenser, but the additional auxiliary power required to drive MDCT fans often consume the additional generator output resulting from the lower backpressure. Spray ponds offer significant advantages over MDCT including superior simplicity and operability, lower power requirements, and lower capital and maintenance costs. The Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and spray upward, blocking the ambient air flow to the spray region as it travels down to the pond below, the OSCS nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. As a result, the water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature (LWBT) of the air in the spray pattern, promoting heat transfer and more efficient cooling. During the late 1970’s the author developed a purely analytical model to predict the thermal performance of the OSCS which was successfully compared with the OSCS at the Columbia Generating Station (CGS) in the mid 1980’s. This paper describes how the OSCS may be employed to supplement the cooling capacity of an existing cooling lake to reduce the temperature of the CCW prior to entering a power plant, resulting in lower main condenser pressures and more net plant output.

The Oriented Spray Cooling System for Heat Rejection and Evaporation

2021 ◽  
Author(s):  
Chuck Bowman ◽  
Robert E. Taylor ◽  
Jerry D. Hubble
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Nuclear Regulatory Commission ◽  
Spray Cooling ◽  
Analytical Models ◽  
Water Droplets ◽  
Flow Through ◽  
Regulatory Commission

Abstract Spray ponds offer significant advantages over mechanical draft cooling towers including superior simplicity and operability, lower preferred power requirements, and lower costs. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and water is sprayed upward, the Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design in which nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. Therefore, each nozzle is exposed to essentially ambient air as water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature of the air in the spray pattern, promoting heat transfer and more efficient cooling. The authors have developed analytical models to predict the thermal performance of the OSCS that are based on classical heat and mass transfer and kinetic vector relationships for spherical water droplets that rely only on generic experimental thermal performance data. The model is not limited in application with regard to spray pressure or nozzle spacing or orientation and is not limited by droplet size considerations. The paper compares the predicted performance of the OSCS with full-scale field test results that were measured in compliance with Nuclear Regulatory Commission requirements at the Columbia Generating Station where the ultimate heat sink is two OSCS.

The Oriented Spray Cooling System for Heat Rejection and Evaporation

2019 ◽  
Author(s):  
Charles F. Bowman ◽  
Robert E. Taylor ◽  
Jerry D. Hubble
Keyword(s):  
Thermal Performance ◽  
Cooling System ◽  
Air Flow ◽  
Ambient Air ◽  
Nuclear Regulatory Commission ◽  
Spray Cooling ◽  
Analytical Models ◽  
Water Droplets ◽  
Flow Through ◽  
Regulatory Commission

Abstract Spray ponds offer significant advantages over mechanical draft cooling towers (MDCT) including superior simplicity and operability, lower preferred power requirements, and lower capital and maintenance costs. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and water is sprayed upward, the Oriented Spray Cooling System (OSCS) is an evolutionary spray pond design in which nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented towards the center of the circle. As a result, each nozzle is exposed to essentially ambient air as water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature (LWBT) of the air in the spray pattern, promoting heat transfer and more efficient cooling. The authors have developed analytical models to predict the thermal performance of the OSCS that are based on classical heat and mass transfer and kinetic vector relationships for spherical water droplets that rely only on generic experimental thermal performance data. Therefore, the model is not limited in application with regard to spray pressure or nozzle spacing or orientation and is not limited by droplet size considerations. This paper describes specific details such as nozzle type, orientation, and drop spectrum and details on the analytical model never before published that are used to predict the OSCS performance. The paper compares the predicted performance of the OSCS with the rigorous full-scale field test results that were measured in compliance with Nuclear Regulatory Commission requirements at the Columbia Generating Station (CGS) where the ultimate heat sink (UHS) is two OSCS.

scholarly journals Experimental Investigation on Heat Transfer Mechanism of Air-Blast-Spray-Cooling System with a Two-Phase Ejector Loop for Aeronautical Application

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3963 ◽  
Author(s):  
Jia-Xin Li ◽  
Yun-Ze Li ◽  
Ben-Yuan Cai ◽  
En-Hui Li
Keyword(s):  
Heat Transfer ◽  
Droplet Size ◽  
Cooling System ◽  
Volumetric Flow Rate ◽  
Least Square Method ◽  
Spray Cooling ◽  
Cooling Capacity ◽  
Least Square ◽  
Two Phase ◽  
Air Blast

This paper presents an air-oriented spray cooling system (SCS) integrated with a two-phase ejector for the thermal management system. Considering its aeronautical application, the spray nozzle in the SCS is an air-blast one. Heat transfer performance (HTP) of air-water spray cooling was studied experimentally on the basis of the ground-based test. Factors including pressure difference between water-inlet-pressure (WIP) and spray cavity one (PDWIC) and the spray volumetric flow rate (SVFR) were investigated and discussed. Under a constant operating condition, the cooling capacity can be promoted by the growth factors of the PDWIC and SVFR with the values from 51.90 kPa to 235.35 kPa and 3.91 L ⋅ h − 1 to 14.53 L ⋅ h − 1 , respectively. Under the same heating power, HTP is proportional to the two dimensionless parameters Reynolds number and Weber number due to the growth of droplet-impacting velocity and droplet size as the increasing of PDWIC or SVFR. Additionally, compared with the factor of the droplet size, the HTP is more sensitive to the variation in the droplet-impacting velocity. Based on the experimental data, an empirical experimental correlation for the prediction of the dimensionless parameter Nusselt number in the non-boiling region with the relative error of only ± 10 % was obtained based on the least square method.

scholarly journals Gas turbine unite inlet air cooling by using an excessive refrigeration capacity of absorption-ejector chiller in booster air cooler

2018 ◽  
Vol 70 ◽  
pp. 03012 ◽  
Author(s):  
Roman Radchenko ◽  
Andrii Radchenko ◽  
Serhiy Serbin ◽  
Serhiy Kantor ◽  
Bohdan Portnoi
Keyword(s):  
Gas Turbine ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Two Stage ◽  
Air Cooler ◽  
Refrigeration Capacity ◽  
Heat Loads

Two-stage Gas turbine unite (GTU) inlet air cooling by absorption lithium-bromide chiller (ACh) to the temperature 15 °C and by refrigerant ejector chiller (ECh) to 10 °C through utilizing the turbine exhaust gas heat for changeable ambient air temperatures and corresponding heat loads on the air coolers for the south Ukraine climatic conditions is analysed. An excessive refrigeration capacity of combined absorption-ejector chiller (AECh) exceeding the current heat loads and generated at decreased heat loads on the air coolers at the inlet of GTU can be used for covering increased heat loads to reduce the refrigeration capacity of AECh. The GTU inlet air cooling system with an ambient air precooling booster stage and a base two-stage cooling air to the temperature 10 °C by AECh is proposed. The AECh excessive cooling capacity generated during decreased heat loads on the GTU inlet air coolers is conserved in the thermal accumulator and used for GTU inlet air precooling in a booster stage of air cooler during increased heat loads. There is AECh cooling capacity reduction by 50% due to the use of a booster stage for precooling GTU inlet ambient air at the expense of an excessive cooling capacity accumulated in the thermal storage.

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.

Study on the Comprehensive Program of Heat Pump Technology Recycling Thermal Power Plants Circulating Water Heat

2013 ◽  
Vol 313-314 ◽  
pp. 759-762
Author(s):  
Yun Feng Ma ◽  
Yan Xiang Liu ◽  
Tao Ji
Keyword(s):  
Heat Pump ◽  
Power Plants ◽  
Waste Heat ◽  
Thermal Power ◽  
Heating System ◽  
Hot Water ◽  
Thermal Power Plants ◽  
Domestic Hot Water ◽  
Circulating Water ◽  
Central Heating

In order to fully recycle power plant’s circulatingwater heat, improve the thermal efficiency and protect the environment, thispaper designs the comprehensive scheme of heat pumptechnology recycling power plant’s circulating water heat, including theboiler mae-up water pre-heating system, the central heating circulatingsystem and the domestic hot water circulating system, which not only run at thesame time but also function independently. Even in non-heating seasons,the waste heat of circulating water can be utilized fully. It is worthmentioning that this paper puts forward to install climate compensationdevice in the central heating system, which can perform intelligent district timesharing control to meet different users’ needs.

scholarly journals Monitoring the efficiency of cooling air at the inlet of gas engine in integrated energy system

2020 ◽  
pp. 344-344
Author(s):  
Andrii Radchenko ◽  
Ionut-Cristian Scurtu ◽  
Mykola Radchenko ◽  
Serhiy Forduy ◽  
Anatoliy Zubarev
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Ambient Air ◽  
Energy System ◽  
Air Conditioner ◽  
Absorption Chiller ◽  
Gas Engine ◽  
Chilled Water ◽  
Air Cooler ◽  
Cooling Air

The fuel efficiency of gas engines is effected by the temperature of intake air at the suction of turbocharger. The data on dependence of fuel consumption and engine electric power on the intake air temperature were monitored for Jenbacher gas engine JMS 420 GS-N.LC to evaluate its influence. A waste heat of engine is rejected for heating water to the temperature of about 90??. The heat received is used in absorption lithium-bromide chiller to produce a cold in the form of chilled water. A cooling capacity of absorption chiller firstly is spent for technological needs and then for feeding the central air conditioner for cooling the ambient air incoming the engine room, from where the air is sucked by the engine turbocharger. The monitoring data revealed the reserves to enhance the efficiency of traditional cooling system of intake air by absorption chiller through deeper cooling. This concept can be realized in two ways: by addition cooling a chilled water from absorption chiller to about 5-7?? for feeding engine intake air cooler or by two-stage cooling with precooling ambient air by chilled water from ACh in the first stage and subsequent deep cooling air to the temperatures 7-10?? in the second stage of intake air cooler by using a refrigerant as a coolant. In both cases the ejector chiller could be applied as the most simple in design.

scholarly journals Digital Twins of the Water Cooling System in a Power Plant Based on Fuzzy Logic

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6737
Author(s):  
Carlos Antonio Alves de Araujo Junior ◽  
Juan Moises Mauricio Villanueva ◽  
Rodrigo José Silva de Almeida ◽  
Isaac Emmanuel Azevedo de Medeiros
Keyword(s):  
Power Plant ◽  
Power Plants ◽  
Cooling System ◽  
Ambient Air ◽  
Fuzzy Rules ◽  
Percentage Error ◽  
Water Cooling ◽  
Twin Model ◽  
Digital Twins ◽  
Water Cooling System

In the search for increased productivity and efficiency in the industrial sector, a new industrial revolution, called Industry 4.0, was promoted. In the electric sector, power plants seek to adapt these new concepts to optimize electric power generation processes, as well as to reduce operating costs and unscheduled downtime intervals. In these plants, PID control strategies are commonly used in water cooling systems, which use fans to perform the thermal exchange between water and the ambient air. However, as the nonlinearities of these systems affect the performance of the drivers, sometimes a greater number of fans than necessary are activated to ensure water temperature control which, consequently, increases energy expenditure. In this work, our objective is to develop digital twins for a water cooling system with auxiliary equipment, in terms of the decision making of the operator, to determine the correct number of fans. This model was developed based on the algorithm of automatic extraction of fuzzy rules, derived from the SCADA of a power plant located in the capital of Paraíba, Brazil. The digital twins can update the fuzzy rules in the case of new events, such as steady-state operation, starting and stopping ramps, and instability. The results from experimental tests using data from 11 h of plant operations demonstrate the robustness of the proposed digital twin model. Furthermore, in all scenarios, the average percentage error was less than 5% and the average absolute temperature error was below 3 °C.

scholarly journals Waste Heat Driven Multi-Ejector Cooling Systems: Optimization of Design at Partial Load; Seasonal Performance and Cost Evaluation

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5663
Author(s):  
Luca Viscito ◽  
Gianluca Lillo ◽  
Giovanni Napoli ◽  
Alfonso William Mauro
Keyword(s):  
Waste Heat ◽  
Cooling System ◽  
Electric Energy ◽  
Cost Evaluation ◽  
Low Grade ◽  
Ambient Temperatures ◽  
Partial Load ◽  
Seasonal Performance ◽  
Ejector System ◽  
Break Even Point

In this paper, a seasonal performance analysis of a hybrid ejector cooling system is carried-out, by considering a multi-ejector pack as expansion device. A 20 kW ejector-based chiller was sized to obtain the optimal tradeoff between performance and investment costs. The seasonal performance of the proposed solution was then evaluated through a dynamic simulation able to obtain the performance of the designed chiller with variable ambient temperatures for three different reference climates. The optimized multi-ejector system required three or four ejectors for any reference climate and was able to enhance the system performance at partial load, with a significant increase (up to 107%) of the seasonal energy efficiency ratio. The proposed system was then compared to conventional cooling technologies supplied by electric energy (electrical chillers EHP) or low-grade heat sources (absorption chillers AHP) by considering the total costs for a lifetime of 20 years and electric energy-specific costs for domestic applications from 0.10 to 0.50 €/kWhel. The optimized multi-ejector cooling system presented a significant convenience with respect to both conventional technologies. For warmer climates and with high electricity costs, the minimum lifetime for the multi-ejector system to achieve the economic break-even point could be as low as 1.9 years.

scholarly journals Innovative Turbine Intake Air Cooling Systems and Their Rational Designing

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6201
Author(s):  
Andrii Radchenko ◽  
Eugeniy Trushliakov ◽  
Krzysztof Kosowski ◽  
Dariusz Mikielewicz ◽  
Mykola Radchenko
Keyword(s):  
Gas Turbines ◽  
Maximum Rate ◽  
Cooling System ◽  
Ambient Air ◽  
Cooling Capacity ◽  
Climatic Conditions ◽  
Air Cooling ◽  
Thermal Loads ◽  
Cooling Systems ◽  
Air Cooling System

The efficiency of cooling ambient air at the inlet of gas turbines in temperate climatic conditions was analyzed and reserves for its enhancing through deep cooling were revealed. A method of logical analysis of the actual operation efficiency of turbine intake air cooling systems in real varying environment, supplemented by the simplest numerical simulation was used to synthesize new solutions. As a result, a novel trend in engine intake air cooling to 7 or 10 °C in temperate climatic conditions by two-stage cooling in chillers of combined type, providing an annual fuel saving of practically 50%, surpasses its value gained due to traditional air cooling to about 15 °C in absorption lithium-bromide chiller of a simple cycle, and is proposed. On analyzing the actual efficiency of turbine intake air cooling system, the current changes in thermal loads on the system in response to varying ambient air parameters were taken into account and annual fuel reduction was considered to be a primary criterion, as an example. The improved methodology of the engine intake air cooling system designing based on the annual effect due to cooling was developed. It involves determining the optimal value of cooling capacity, providing the minimum system sizes at maximum rate of annual effect increment, and its rational value, providing a close to maximum annual effect without system oversizing at the second maximum rate of annual effect increment within the range beyond the first maximum rate. The rational value of design cooling capacity provides practically the maximum annual fuel saving but with the sizes of cooling systems reduced by 15 to 20% due to the correspondingly reduced design cooling capacity of the systems as compared with their values defined by traditional designing focused to cover current peaked short-term thermal loads. The optimal value of cooling capacity providing the minimum sizes of cooling system is very reasonable for applying the energy saving technologies, for instance, based on the thermal storage with accumulating excessive (not consumed) cooling capacities at lowered current thermal loads to cover the peak loads. The application of developed methodology enables revealing the thermal potential for enhancing the efficiency of any combustion engine (gas turbines and engines, internal combustion engines, etc.).

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