Heat exchange – Regenerator – Heat collector
Patent
1982-07-28
1984-02-07
Davis, Jr., Albert W.
Heat exchange
Regenerator
Heat collector
60526, 165185, F28D 1700
Patent
active
044297327
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to Stirling-cycle engines, to other regenerative thermal machines, and more particularly to a new method for the construction of the regenerator element common to all such machines. The new method involves the deliberate incorporation of certain anisotropic materials such as pyrolytic graphite to improve the heat transfer and storage performance characteristics of the regenerator. This will enhance the overall performance of regenerative thermal machines, especially those which embody a practical approximation to the well known Stirling thermodynamic cycle in the production of both mechanical power (i.e. prime movers, compressors, fluid pumps) and refrigeration (i.e. refrigerators, air conditioners, heat pumps, gas liquefiers).
A Stirling-cycle engine is a machine which operates on a closed regenerative thermodynamic cycle, with periodic compression and expansion of a gaseous working fluid at different temperature levels, and where the flow is controlled by volume changes in such a way as to produce a net conversion of heat to work, or vice versa. The regenerator is a device which in prior art takes the form of a porous mass of metal in an insulated duct. This mass takes up heat from the working fluid during one part of the cycle, temporarily stores it within the machine until a later part of the cycle, and subsequently returns it to the working fluid prior to the start of the next cycle. Thus the regenerator may be thought of as an oscillatory thermodynamic sponge, alternately absorbing and releasing heat with complete reversibility and no loss.
A reversible process for a thermodynamic system is an ideal process, which once having taken place, can be reversed without causing a change in either the system or its surroundings. Regenerative processes are reversible in that they involve reversible heat transfer and storage; their importance derives from the fact that idealized reversible heat transfer is closely approximated by the regenerators of actual machines. Thus the Stirling engine is the only practical example of a reversible heat engine which can be operated either as a prime mover or as a heat pump.
BACKGROUND
The Stirling-cycle engine was first conceived and reduced to practice in Scotland 164 years ago. A hot-air, closed-cycle prime mover based on the principle was patented by the Reverend Robert Stirling in 1817 as an alternative to the explosively dangerous steam engine. Incredibly, this event occurred early in the Age of Steam, long before the invention of the internal combustion engine and several years before the first formal exposition of the Laws of Thermodynamics.
Air was the first and only working fluid in early 19th century machines, whereas hydrogen and helium have been the preferred working fluids for modern machines. In Great Britain, Europe, and the United States thousands of regenerative hot air prime movers in a variety of shapes and sizes were widely used throughout the 19th century. The smaller engines were reliable, reasonably efficient for their time, and most important, safe compared with contemporary reciprocating steam engines. The larger engines were less reliable, however, because they tended to overheat and often succumbed unexpectedly to premature material failure.
Toward the end of the 19th century the electric motor and the internal combustion engine were developed and began to replace not only the Stirling-cycle engines, but also the reciprocating steam engines of that era. These new machines were preferred because they could produce greater power from more compact devices and because they were more economical to manufacture. The limitations of early, as well as those of current Stirling engines are in part directly attributable to the design and performance characteristics of the regenerator element. Both the specific power capacity and the overall thermal efficiency of regenerative thermal machines are direct consequences of the inherent performance characteristics and heat transfer properties of the regenerator.
Since Worl
REFERENCES:
patent: 3445910 (1969-05-01), Duryee et al.
patent: 3913666 (1975-10-01), Bayliss
Davis Jr. Albert W.
Morton, Jr. W. Brown
LandOfFree
Regenerator structure for stirling-cycle, reciprocating thermal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Regenerator structure for stirling-cycle, reciprocating thermal , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Regenerator structure for stirling-cycle, reciprocating thermal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2157314