Efficiency of Steam and Hot Water Heat Distribution Systems

摘要

This report will provide some general guidance on the selection of distributionmedium (steam or hot water) and temperature for heat distribution systems. The report discusses the efficiency of both steam and hot water heat distribution systems in more detail. The results of several field studies using data from boiler plant logs and measured heat losses are given. For steam, an efficiency analysis for the steam heat distribution system at Hawthorne Army Ammunition Plant is summarized. This analysis is based on the limited data available from the boiler logs maintained at the central plant. From this information, along with energy and mass balances that are constructed from the central plant data, gross measures of efficiency are obtained. The results of the analysis show that only 43.5% of the steam input to the distribution system is used to meet the required space heating load. The results also indicate that on average only 46.2% of the steam that leaves the plant returns as condensate. By converting this steam distribution system to a low temperature hot water heat distribution system, savings would exceed $292,000 for the 181-day study period, which represents a typical heating season. For hot water based systems this report describes two field projects underway at U.S. Army bases.