Economic Analysis and Design of Industrial Heat Pumps for Low-Temperature Waste-Heat Utilization.

摘要

Work performed on heat pump optimization and a pilot plant design is documented. A general thermodynamic review of the conventional Rankine Cycle Heat Pump and its comparison to the alternative cycles, i.e., the Open-Open/sup TM/ and Open Cycle Heat Pumps are presented. These alternate cycles utilize the waste heat stream as the process fluid in the case of the Open-Open/sup TM/ Cycle by simply flashing the hot waste stream in a subatmospheric flash tank, or as in the case of the Open Cycle Heat Pump water is used as the process fluid and is separated from the waste heat stream. In the latter system, the process fluid is evaporated in a kettle type reboiler which provides the means for separating the process stream from the waste heat stream. A parametric analysis was performed for various operating conditions to set a base plant size and to develop a cost of energy for both the Open-Open/sup TM/ and Open Cycle Heat Pumps. The present and future energy cost scenarios for the heat pump were compared with fossil-fuel-generated energy. An Open-Open/sup TM/. Heat Pump demonstration size plant was designed to verify the heat pump concept, and it represents the first step in the commercialization of the heat pump system. The design package includes system diagrams and component specifications in sufficient detail to facilitate the securing of specific equipment and the construction of a 5000-lb/h Open-Open/sup TM/ Heat Pump. For the design case, a 150 exp 0 F source stream will be flashed in a three-foot diameter flash tank. The generated stream (4372 lb/h or 0.495% of the source stream) will be compressed from 3.28 psia to a process pressure of 10 psig by three single-stage, motor-driven centrifugal compressors. Desuperheating is provided between stage to reduce the compression power for the second and third stages. (ERA citation 07:044066)