Engineering and Cost Analysis of a Dry Cooling System Augmented with a Thermal Storage Pond.

摘要

An engineering and cost study of the capacitive thermal storage pond added to a state-of-the-art dry cooling system is described. The purpose of the study was to assess the potential for reducing the cost of all-dry cooling for thermal electric power plants using a dry cooling system that includes a thermal storage pond. Using the modified BNW-I computer code,the effect of varying significant design parameters was investigated. The parametric study included studying the effects of varying turbine type,pond size,replacement energy costing,capacity penalty methodology,pond location with respect to the dry cooling tower,design temperature,and site location (meteorology). Incremental power production costs for dry cooling (i.e.,the portion of the cost of bus-bar electricity from the plant which is attributable to the cost of building and operating the heat rejection system) with a thermal storage pond system were determined for meteorologies of both Wyodak,Wyoming and Phoenix,Arizona. For Wyodak the incremental cost of dry cooling with a thermal storage pond was 2.81mills/kWh as compared to 2.55mills/kWh for a system without a thermal storage pond. For Phoenix the incremental cost of dry cooling with a thermal storage pond was 3.66mills/kWh as compared to 4.31mills/kWh for a system without a thermal storage pond. If the use of a modified conventional turbine with the dry-cooled system is stipulated in order to stay with proven technology for large turbines,then results of this study show that in extremely hot climates the thermal storage pond can reduce the cost of dry cooling. If no cost penalty is assigned to high back pressure turbines and it can be used,then the thermal storage pond has no advantage in hot climates. However,collateral use of the pond for makeup or emergency cooling water storage may decreae the cost. (ERA citation 04:022598)