Thermal Performance of Spray-Canal Cooling Systems

1980 ◽  
Vol 102 (4) ◽  
pp. 776-781
Author(s):  
S. K. Chaturvedi ◽  
R. W. Porter

Spray canals are alternatives to cooling ponds and towers for steam-electric power plants. The literature of thermal modeling is reviewed. A rational analysis supported by field experiments at two large central power stations has led to correlation of local spray cooling performance in terms of two dimensionless groups, one of which is dependent mainly on the type of spray module, and the other is a heating-humidification interference-allowance parameter which depends on wind speed and direction and the type and placement of modules. The analysis is incorporated into a systems performance model for arbitrary canal layout. Examples presented are the circular, race-track and straight double-back canals. Implications for design are discussed.

2014 ◽  
Vol 21 (2) ◽  
pp. 327-336 ◽  
Author(s):  
Robert Kasperek ◽  
Mirosław Wiatkowski

Abstract Adopted in 2009, the Directive of the European Parliament and of the Council on the promotion of the use of energy from renewable sources sets out the rules for how Poland is to achieve the 15% target of total primary energy from renewables by 2020. However, there are fears that the goals set out in this Directive may not be met. The share of Renewable Energy Sources (RES) in national energy consumption (150 TWh) is estimated at 8.6 TWh in 2009 and 12 TWh in 2011 (5.7 and 8% respectively). The level of RES in Poland until 2005 was approx. 7.2%. The analysis of RES technologies currently in use in Poland shows that in terms of the share in the total capacity, the 750 hydro-electric power plants which are currently in operation (with the overall capacity of almost 0.95 GW) are second only to wind power stations (2 GW). The authors have studied the Nysa Klodzka River in terms of possible locations for hydro-electric facilities. Eight locations have been identified where power plants might be constructed with installed capacities ranging from 319 to 1717 kW. The expected total annual electric power generation of these locations would stand at approx. 37.5 GWh.


Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6365
Author(s):  
Alexander Genbach ◽  
Hristo Beloev ◽  
David Bondartsev

A new porous system in power plants allowing the management of the crisis of heat exchange at boiling water in porous structures has been investigated. This study refers to the thermal power plants of electrical power stations and devices for cutting natural and artificial mineral media. Combustion chambers and supersonic nozzles were cooled by different porous structures. The optimum cell sizes of the porous structures were determined and data on the heat transfer capacity for the (critical) heat flow were obtained. A thermal device in the form of a rocket-type burner with a detonation jet showed high efficiency for capillary-porous and flow-through cooling systems. The economic effect per burner is not less than 200–300 dollars, and the coolant consumption is reduced by dozens of times, which is environmentally important. A comparative evaluation of the investigated structures and coatings has advantages over other cooling systems. The integration of mesh structures with capillary-porous coatings of natural mineral media produces a synergistic effect of combining them into a technology of their manufacturing, the expansion of critical loads removal and control of the limit state of the coatings.


1980 ◽  
Vol 102 (2) ◽  
pp. 210-214 ◽  
Author(s):  
R. W. Porter ◽  
M. Jain ◽  
S. K. Chaturvedi

Thermal performance of an open atmospheric spray pond or canal depends on the direct-contact evaporative cooling of an individual spray unit (spray nozzle or module) and the interference caused by local heating and humidification. Droplet parameters may be combined into a dimensionless group, number of transfer units (NTU) or equivalent, whereas large-scale air-vapor dynamics determine interference through the local wet-bulb temperature. Quantity NTU were implied from field experiments for a floating module used in steam-condenser spray canals. Previous data were available for a fixed-pipe nozzle assembly used in spray ponds. Quantity NTU were also predicted using the Ranz-Marshall correlations with the Sauter-mean diameter used as the characteristic length. Good agreement with experiments was shown for diameters of 1–1.1 cm (module) and 1.9 mm (fixed-pipe nozzle).


1974 ◽  
Vol 96 (3) ◽  
pp. 286-291 ◽  
Author(s):  
R. W. Porter ◽  
K. H. Chen

A numerical analysis is presented for the heat-exchanger performance of open, direct-contact evaporative spray cooling of large electric power plants. Floating spray modules are placed essentially in series in this large-scale application. The module “unit performance” is formulated in terms of Number of Transfer Units (NTU) as suggested by elementary drop dynamical theory. The overall canal performance is analyzed by a numerical procedure of marching along from pass to pass of spray modules. Hydrodynamic mixing within the canal and air-vapor circulation interference above the canal are incorporated as suggested by theoretical considerations and field experiments. The analysis was applied to a number of field tests of several spray canals and the apparent values of NTU were correlated with wind speed.


1983 ◽  
Vol 15 (10) ◽  
pp. 135-147
Author(s):  
Maurice A Shapiro ◽  
Meryl H Karol ◽  
Georg Keleti ◽  
Jan L Sykora ◽  
A J Martinez

It has been shown that several pathogenic organisms may be frequently found in thermal effluents and cooling systems of coal fired power plants. One of them is pathogenic Naegleria fowleri, the causative agent of an acute fatal human disease - primary amoebic meningoencephalitis (PAM). In our study two out of eight power plants investigated, harbored pathogenic N. fowleri in heated water or cooling towers. The occurrence of this organism was related to elevated temperatures. No significant correlation was found for other biological and chemical parameters. In addition, pathogenic Acanthamoeba which causes granulomatous amoebic encephalitis (GAE) was found in the tested heated effluents from coal fired power plants. Non-pathogenic strains of N. fowleri as well as other free-living and “harmless” amoebae were also very abundant in effluents from all investigated coal fired power plants and cooling towers. It has been reported that several species of nonpathogenic amoebae were isolated from humidifiers and air conditioning systems. Serological testing of symptomatic human subjects has indicated that these organisms may be one of the causative agents of hypersensitivity pneumonitis. An experimental study performed in our laboratory involved testing of guinea pigs sensitized by injection of axenic, non-pathogenic N. gruberi. Delayed onset skin reactivity was apparent in all animals injected with the antigen. Antibodies were detected in all sensitized animals. Bronchial provocation challenge employed to investigate pulmonary hypersensitivity was also used, and yielded positive results. All the sensitized animals displayed delayed onset respiratory responses. The results of this study indicate that not only pathogenic but also non-pathogenic free-living amoebae may be important causative agents of human disease. The occurrence of these organisms in cooling systems from coal fired power plants indicates that these facilities may be an important source of infection.


1989 ◽  
Vol 111 (3) ◽  
pp. 193-203
Author(s):  
James A. Dirks ◽  
Clement J. Chiang

Typically, solar thermal power plants are designed to minimize the levelized energy cost. However, to maximize the benefit of a solar plant and, hence, maximize the wealth of an investor or a utility, a solar plant should be designed and operated with the objective of maximizing the value-to-cost ratio. This paper describes a value and cost analysis of solar central receiver power plants using molten salt external receiver technology. These plants were assumed to operate within the service area of the Southern California Edison Company. The SOLERGY computer code was used to simulate the performance of the solar plants using 1984 weather data for Barstow, California. A value-maximizing dispatch strategy that uses thermal storage to shift operation of the turbine from nonpeak demand periods to the utility’s peak demand period, is shown to greatly increase the value of a solar central receiver power plant with little increase in the levelized energy cost. Results are presented as functions of storage capacity, type of dispatch strategy, size of the field relative to the turbine, and turbine size.


2021 ◽  
Vol 11 (2) ◽  
pp. 727 ◽  
Author(s):  
Myeong-Hwan Hwang ◽  
Young-Gon Kim ◽  
Hae-Sol Lee ◽  
Young-Dae Kim ◽  
Hyun-Rok Cha

In recent years, photovoltaic (PV) power generation has attracted considerable attention as a new eco-friendly and renewable energy generation technology. With the recent development of semiconductor manufacturing technologies, PV power generation is gradually increasing. In this paper, we analyze the types of defects that form in PV power generation panels and propose a method for enhancing the productivity and efficiency of PV power stations by determining the defects of aging PV modules based on their temperature, power output, and panel images. The method proposed in the paper allows the replacement of individual panels that are experiencing a malfunction, thereby reducing the output loss of solar power generation plants. The aim is to develop a method that enables users to immediately check the type of failures among the six failure types that frequently occur in aging PV panels—namely, hotspot, panel breakage, connector breakage, busbar breakage, panel cell overheating, and diode failure—based on thermal images by using the failure detection system. By comparing the data acquired in the study with the thermal images of a PV power station, efficiency is increased by detecting solar module faults in deteriorated photovoltaic power plants.


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