scholarly journals Engineering and cost analysis of a dry cooling system augmented with a thermal storage pond

1978 ◽  
Author(s):  
M.K. Drost ◽  
R.T. Allemann
1983 ◽  
Vol 105 (2) ◽  
pp. 174-180 ◽  
Author(s):  
E. C. Guyer ◽  
M. W. Golay

The use of a capacitive Thermal Storage Reservoir (TSR) initially filled with cold water as part of a dry cooling system for a central power station is attractive economically if the reservoir can be designed to operate in an approximate “plug-flow” mode—discharging cold water to the condenser and filling with hot water from the cooling tower. Such a system would avoid the loss of station capacity associated with dry cooling at high dry-bulb temperatures, and the economic penalties due to such losses when they are coincident with electrical demand peaks (as is common in the United States). The initial employment of this concept is most likely to occur in solar-powered thermal electric power stations in arid climates in view of the likely low thermal efficiency and limited cooling water access of such plants. Buoyant flow stratification hinders attaining this goal since it can cause “short circuiting” of the TSR. For adequate flow control, a long narrow reservoir configuration is desirable. In investigating the behavior of such a TSR experimentally, it was found over the range of cases examined that injection of water into a long narrow reservoir which is initially at a different temperature always results in a stratified flow superimposed upon the gross plug flow of the TSR, and it was found that acceptable performance could be obtained inexpensively by placing flow-constricting barriers at regular intervals along the reservoir length. Experimental investigation of barrier design and spacing has permitted definition of a practical prototype TSR design which provides approximately 87 percent of the thermal capacity of a plug flow TSR.


Author(s):  
Nicola Palestra ◽  
Giovanna Barigozzi ◽  
Antonio Perdichizzi

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.


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