HOTCALC Microcomputer Software for Analysis of Commercial Water Heating System Performance

摘要

The application, design, and sizing of commercial water heating systems has been hampered by the lack of an accessible tool forrnevaluating long-term performance and operating energy costs. This lack of resources has limited the application of high-efficiencyrnalternative water heating systems such as heat pump water heaters, refrigeration heat reclaim units or desuperheaters, and waste heatrnrecovery systems. The Electric PowerResearch Institute and the Empire State Electric Energy Research Corporation have developed thernHOTCALC microcomputer software to fill that need. HOTCALC uses a three-node stratified tank model and hourly performancernsimulations for each month to provide performance estimates for five system types: electric storage water heaters, fuel-fired storagernwater heaters, heat pump water heaters, refrigeration heat reclaim, and waste heat recovery. A detailed recirculation loop model isrnincluded. HOTCALC is the first water heating analysis software that addresses the dynamic performance of heat pump water heatersrnand refrigeration heat reclaim systems, and the first to consider interactions between space cooling loads and heat pump water heaterrnoperation. Unlike other common models, it uses hourly inputs rather than longer-term average load and operations figures. Outputsrninclude energy consumption, estimated demand, efficiency, and utility cost for all water heating system components. For heat pump waterrnheaters, estimates of beneficial cooling output and value are provided.rnHOTCALC is designed for easy use and includes features for comparison of results from multiple runs, results and system designrndiagnostics, and a detailed context-sensitive help system with page references to ESEERCO's and EPRI's companion 310-pagernCommercial Water Heating Applications Handbook, EPRI TR-100212. HOTCALC provides reliable performance estimates andrnremoves much of the uncertainty in system selection and design, thus facilitating the use of more efficient and effective commercial waterrnheating systems. Reactions from users have been positive and comparisions to measured performance data have been very favorable.