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An approach to
converting heat energy into electrical potential uses
gas engines designs. In such engines, the conversion task is accomplished
with simple
one-cylinder engine that support the conversion of heat energy
into mechanical energy available for work, although the details of
the design for extracting the mechanical energy varies. These single-cylinder engines - in fact are
truly complete engines - but are quite suited as converters because
they contain much less moving parts and as such expose relatively
far fewer degrees of freedom of failure.
These engines, of course, are of several varied
forms and designs of Gas Engines over the years. So in
adopting a design in this report for the purposes of all related
analysis, issues in the adoption gas engine
base design that is of consideration in relation to the design being adopted here is
about any issue of proprietary
rights, and as such the one of choice has expired
proprietary rights. Such engine could therefore be subjected to
prospective improvement designs without interference and such
that the improvements being
presented can still be treated as intellectual property rights.
Basic Converter
Gas Engine Design
A design of gas Engine that meets the requirement of
unimpeded design consists of two straight pipes joined at
a pair of ends in vertical alignment but separated with high
temperature ceramic thin ring-disc. Within the pipes is placed
a rod to which is attached two pistons positioned at
design-specified distance apart. In the vertical oriented
position the upper-piston, also called the Displacer Piston, is positioned well inside the upper pipe
which has hemispherical closed top. The lower-piston, also
called the Power Piston, is equally positioned well inside the
lower pipe which has a diameter differential shortly above the
piston. The upper closed pipe is also fitted with an external
heat-source heat exchanger - the design of which depends on the
energy source being adopted. Similarly the larger drum section
of the lower pipe is also fitted with an external heat-sink heat
exchanger. The length of the upper-pipe spanned by the heat
source heat exchanger heat constitutes the region of heat
transfer into the gas; and similarly, the length of the
lower-pipe spanned by the heat sink heat exchanger is the region
through which heat is transferred out of the gas. The pipe is
filled with nitrogen gas at the relatively high pressure [bars]
of 20:100 ratio. Indeed the power unit could by design be
working at high pressures [such as 20 till 100 bar]. The rod to
which the pistons are affixed extends beyond the pipes to the
external of the lower pipe while terminating inside the upper
piston. The lower-piston is affixed by
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being slid over the rod and has a seal on its lateral wall to
cause a seal on the inner wall of the lower-pipe, which is covered
at the base with a flanged cap with a center-puncture through which
the rod extends.
In cold start, the gas above
the upper-piston heats up and pushes the piston down and
consequentially pushes the rod out of the engine-cylinder while also
causing the cold gas in the heat-sink section to get forced to flow
into the heat-source section causing more displacement pressure and
therefore more displacement of the upper-piston; at the appropriate
length of extension of the rod into the outside, a mechanical
device, often a flywheel-mechanism attached to the end of the rod
then pushes the rod back in and thereby forcing the hot gas to flow
between the upper-piston and the inner-wall of the heat section into
the region between the pistons where the heat sink is attached. The
heat-sink removes the heat from the hot gas causing gas volume
reduction and therefore a differential pressure that starts pushing
the upper-piston back down followed by a flow of the gas from the
sink-section to the source section as previously and therefore
providing a cyclic engine dynamics.
Although the operation
dynamic has been presented in terms of a flywheel mechanism, as a
Energy Converter Gas Engine in contrast to a locomotion engine, any
device that supports the effects of the flywheel will do just as
well.
Certain unique features
due to design and conventional design properties changes attend this
converter gas engine that are worthy of note.
Adopted Design
Modifications
Most significant relative change though implicitly stated is the use of
nitrogen gas instead of the often used gases of hydrogen or helium
or air. Given that nitrogen is the main part of Air the design as
such may be deemed to be
using air as compared with conventional design. Though insulating,
nitrogen is
preferred by design because of safety considerations: Hydrogen is highly
reactive and so, forms bonds with the metals and thereby causing
metal embrittlement, and therefore unpredictable consequential
failure. Helium , on the other hand , does not have this problem,
but is a special gas and not readily available; Nitrogen however, is relatively more readily available,
and does not cause metal embrittlement.
Cursory comparative rationalization of the sources of difference
between the gases shows that the gases with only s-orbital electron
configurations, as Hydrogen and Helium, seem to have higher |
thermal conductivity, meaning
that the more energy levels characterize the gas the lower the thermal
conductivity, while the sp and sp-hybridized molecules, such as
Nitrogen, are relatively
insulating and therefore the molecules by the cylinder inner-wall interface
will keep absorbing the heat energy being transferred into the
engine by heat conduction but without much of that heat energy being
transferred deeper into the cylinder and to the gas molecules farther from the wall.
The insulating
characteristics of nitrogen introduces and intensifies the already
problematic issue of slow transfer of heat into the gas, and
the need for uniform heating of the gas. The impact of low heat
conduction of the gasses, has often being the reason for opting
against the use of nitrogen as the gas is insulating. In compensating for this
insulating effect, the heat source region of the engine has design changes that uses radiative heat transfer,
such as would permit deeper penetration of the heat energy into the
bulk-gas. The heat source region therefore is of composite
concentric cylindrical design such that the material
of the inner cylinder have high emissivity relatively low
temperature as to enable more radiative heat transfer. Moreover, the inner wall
also has
reflectivity to cause the radiated heat energy contained within the
gas and not get reabsorbed into the wall. this design specification
is by no means an easy task, of course.
By this design, clearly a
customized energy converter technology can be developed for the
conversion of heat energy into mechanical energy which can then be
converted into electrical energy with efficacious mechanisms for
extracting the mechanical energy potential. The details of the
design of the mechanism, of course, is application-specific.
The design of this mechanism therefore is one of the areas of
specialization of the application to specific energy conversion
needs. |
