Design and development of a reciprocating low-temperature freon expander
The design and development of a 20-ton refrigeration system to be powered by 140/sup 0/F waste hot water is described. The system consists of a Rankine cycle driving a reverse-Rankine cycle, integrated in that they share a common working fluid (R-22), a common condenser, and a common crankcase housing the expander and compressor. A reciprocating single-acting counterflow expander provides a combination of high efficiency in the desired capacity range, modularity, and adaptability to existing compressors. Because the temperatures and pressures of the Rankine cycle fell within the design envelope of a standard refrigeration compressor, the compressor and expander could be housed within the same crankcase by converting some of the compressor cylinders to expander cylinders by replacing the cylinder heads. The expander heads incorporate rotary valves which offer high flow coefficients; they permit higher flow areas and more straightforward flow paths than poppet valves. Rotary valve design presents little risk considering the use of compatible oil, the low operating temperatures, and close clearances that are consistent with minimal differential thermal expansion. Valve timing was optimized by a computerized finite difference technique that performed mass and energy balances and calculated flow through the valves as the crankshaft progressed incrementally. This calculation predicted that breathing losses would amount to only 13%.Thermal losses are expected to be minimal, for temperature differences are low and thermal transport properties poor. Mechanical losses are expected to be less than those of an internal combustion engine; m.e.p. is comparable, and the expander cylinder environment is less hostile to the lubricating oil.
- Research Organization:
- Foster-Miller Associates, Inc., Waltham, MA (USA)
- DOE Contract Number:
- W-7405-ENG-26
- OSTI ID:
- 6292924
- Report Number(s):
- CONF-810812-34; ON: DE81028609
- Resource Relation:
- Conference: IECEC conference, Atlanta, GA, USA, 9 Aug 1981
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HEAT RECOVERY EQUIPMENT
DESIGN
OPERATION
RANKINE CYCLE ENGINES
REFRIGERATING MACHINERY
COMPRESSORS
COMPUTERIZED SIMULATION
CONDENSERS
FINITE DIFFERENCE METHOD
FREONS
HOT WATER
INDUSTRIAL PLANTS
LIQUID WASTES
WASTE HEAT
WASTE WATER
WORKING FLUIDS
ENERGY
ENGINES
EQUIPMENT
FLUIDS
HALOGENATED ALIPHATIC HYDROCARBONS
HEAT
HEAT ENGINES
HYDROGEN COMPOUNDS
ITERATIVE METHODS
MACHINERY
NUMERICAL SOLUTION
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
SIMULATION
WASTES
WATER
320303* - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Equipment & Processes
320304 - Energy Conservation
Consumption
& Utilization- Industrial & Agricultural Processes- Waste Heat Recovery & Utilization