AU595795B2 - Regenerative thermal engine - Google Patents

Description

-L I ~i-~9~1 c AU-AI S6 28 5/ 86 WORLD INTELLECTUAL PROPERTY ORGANIZATION International Bureau

PCT

0i~r INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (51) International Patent Classification 4 (11) International Publication Number: WO 86/ 04388 FO2B 77/02, 33/44 Al (43) International Publication Date: 31 July 1986 (31.07.86) (21) International Application Number: PCT/US86/00137 (81) Designated States: AT (European patent), AU, BE (European patent), BR, CH (European patent), DE (Eu- (22) International Filing Date: 27 January 1986 (27.01.86) ropean patent), DK, FI, FR (European patent), GB (European patent), IT (European patent), JP, KR, LU (European patent), NL (European patent), SE (Euro- (31) Priority Application Numbers: 696,022 pean patent).

805,184 (32) Priority Dates: 29 January 1985 (29.01.85) Published December 1985 (05.12.85) With international search report.

Before the expiration of the time limit for amending the (33) Priority Country: US claims and to be republished in the event of the receipt R of amendments.

(71)(72) Applicant and Inventor: PAUL, Marius, A.AUS/US]; 6062 Ronald Circle, Cypress, CA 90630 (US).

(74) Agent: PETERSON, Richard, Esty; Bielen and Peterson, 100 Webster Street, Suite 101, Oakland, CA 94607 A.O.J.P. 1 1 SEP 1986.

AUSTRALIAN

T RGEN-ERtV TERMAn E 1 3 AUG 1986 :itli 4Y ard Is ci r PATENT OFFICE (54) Title: REGENERATIVE THERMAL ENGINE (57) Abstract The regenerative thermal engine relates to the field of reciprocating internal combustion engines and in particular to thermal engines that approach adiabatic conditions through effective integration of novel components and operations. Suggested reliance on ceramic components for adiabatic operation has created problems inherent in the materials and in the compatibility of the components with other metallic components. To solve problems encountered in increasing engine efficiency a novel regenerative cylinder has been devised to operate with a piston arranged to avoid contact with the cylinder wall. The regenerative wall or liner has a structure with surface cells designed to admit, hold and release compressed air during the combustion cycle to thermally insulate the cylinder from the heat of combustion.

Other components and arrangements combine to enable effective generation and use of higher operating pressures and temperatures to achieve overall engine efficiencies surpassing conventional systems for use in transportation and stationary generation of electrical and mechanical energy.

rI x 1 I I I iL-~ il~ BACKGROUND OF THE INVENTION This invention relates generally to thermal piston engines, and more particularly to structural and conceptual improvements that increase the efficiency of such engines.

The regenerative thermal engine of this invention combines unique components to achieve high efficiencies and low engine weights in compact, structurally and thermally integrated units. aThe y U U .jt f thi: in:ntion iAto devise adiabatic engines which are capable of operating at high pressures and temperatures utilizing the total expansion of the generated gases without the size and weight customarily associated with such engines. Further, the use of exotic materials such as ceramics which add to the expense and complexity of such engines is not necessary in the thermal engines devised, enabling a flexibility in the choice of competing materials for construction of highly efficient but low cost engines.

The superior characteristics of the piston engine have 4 numerous applications, with both the military and commercial applications in transport and power generation well known. Numerous developmental 0 9 .0 0 e o- 0 o o oo o oo• Pat hs are available for reducing specific fuel consumption, aiid for reducing the size and weight of the engine. Many of th~ese paths, however, lead to undersized power plants of high complexity and cost.

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S S In designing a high temperature, adiabatic engine, major problems are involved in selection of materials and design of structures capable of withstanding both high temperatures and pressures. Formulation of systems that can effectively and fully utilize the expanded pressure spectrum without thermal losses, particularly those losses associated with cooling local zones of high temperature, is a major challenge.

In order to effectively utilize the runout thermal energy of the resulting working agent in a compact unit, it is necessary to integrate select components which can most efficiently operate under conditions of low, medium or high pressures. A complete utilization of the thermal energy developed in the combustion process can be accomplished only in the case of an effective harnessing of the total expansion of the combustion gases, from the highest pressure of the cycle to the lowest pressure of the ambient air, exhausting the working gases at the lowest temperature possible.

However, a super-long expansion in the cylinders of a reciprocating piston engine is possible only in very large engines with very low rotations. In such engines as the Sulzer and the Burmmeister and Wain naval engines, in which the ratio of stroke to bore reach 3-4, thermal efficiencies exceed 53%.

In the 7200 rotation of the crank shaft during the thermal 3 i~i i SS 0 oo S S o S 5 5 0 o o 5 0 o o 0 0 S S@ cycle of a four stroke engine, the evolution of the pressure in the time of the intake, compression, combustion-expansion and exhaust, define various periods of low pressure, medium pressure, and high pressure.

The low and medium pressure periods of the cycle cover 80%-90% of the cycle. Only 10-20% of the cycle or 70% of the 7200 cycle rotation is associated with the high pressure period of final compression, combustion and initial expansion. Despite the very short duration of the high pressure period (10-20% of cycle time) engines are constructed to withstand this maximum pressure throughout the 7200 rotation cycle.

The mass of metal and high strength structure is wasted during the rest of the cycle in which only medium and low pressure is encountered.

As a result of this factor, actual engines are big, heavy, expensive and inefficient.

In a basic embodiment of an engine capable of effective utilization of the full spectrum of expansion pressures is an integrated rotary-reciprocal compound engine which develops an equivalent compression ratio to the long stroke engines described. The low and medium pressures are developed in the rotary component and include 40% of the cycle in a rotocompressor for compression and 40% in a rotoexpander for expansion.

The high pressures are developed in final compression and initial expansion in the reciprocal piston component.

Conventional engines are limited in peak pressures to approximately 150 bars. This level establishes a practicai limit for C r 4 0 66 0* oo 0 odo 0, so Go: 0.

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compression ratios including supercharged engines. Thermal efficiency rises with increases in the compression ratio, but the limited peak pressure for conventional engines limits thermal efficiency. Peak pressure is limited in principle by friction, particularly by friction forces associated with the side thrust of the piston against the cylinder liner from the angular oscillation of the connecting rod, and, inertia, particularly inertial forces associated with the increase in size and weight of moving parts designed to accommodate increased peak pressures.

These adverse factors have in the past defined the limit of evolution of conventional engines.

The unique engine designs described herein include features that resolve/the problems described and enable increased peak pressures to be achieved in compact lightweight engines.

00 se 65 6 as5 0.0be*#0 S S S *S 5 5 5 S SSOO 5 0 555 0 5 55 CO os 0 0 *0 0 00 6 0 55 5 R* 5 5 00 0 .1 550 S@ S S. S s eI 5050 S S i-i r'j_ 6- It is the object of the present invention to provide a compound rotary-reciprical engine which integrates select designs and components to achieve conditions for optimising engine operating parameters.

In one broad form the present invention provides a compound rotary-reciprocal engine comprising: a. a high pressure, two-cycle reciprocator component having a single cylinder, with at least one piston reciprocally movable in the cylinder with a predetermined displacement volume, the piston and cylinder forming in part a combustion chamber for combustion of gases, intake port means for introducing air into the cylinder and exhaust port means for removing combustion gases from the cylinder; b. a medium pressure, positive displacement rotary component in I :e integral combination with said reciprocator component, said rotary component having a unitary compressor segment with an air intake and a iS compressed air exit in direct communication with said intake port means of the reciprocator component and an expander segment with a combustion gas exit and a combustion gas intake in direct communication with said exhaust port means of said reciprocator component, wherein the intake port means and the compressed air exit form a compressed air passage and the exhaust port means and combustion gas intake form a combustion gas passage, each passage having a volume less than the displacement volume of the reciprocator component; and, c. a fuel injection means for injecting fuel into said cylinder of S. said reciprocator component.

A further broad form of the present invention provides a compound rotary-reciprocal engine comprising: a. a high pressure, reciprocator component including a cylinder with an insulator liner comprising a regenerator liner having cells communicating with the cylinder for periodic admission and release of compressed air, a piston reciprocally movable in the cylinder forming in part a combustion chamber for combustion of gases, intake means for introducing air into the cylinder and exhaust means for removing combustion gases from the cylinder; KLN/1565b T %A, 1 0U -FS DO -7b. a medium pressure, positive displacement rotary component in integral combination with said reciproctor component, said rotary component having a unitary compressor segment with an air intake and a compressed air exit in communication with said intake means of the reciprocator component and an expander segment with a combustion gas exit and a combustion gas intake in communication with said exhaust means of said reciprocator component; and c. a fuel injection means for injecting fuel into said cylinder of said reciprocator component.

A still further broad form of the present invention provides a compound rotary-reciprocal engine comprising: a. a high pressure, two-cycle recriprocator component including a single cylinder, at least one piston reciprocally movable in the cylinder forming in part a combustion chamber for combustion of gases, intake means for introducing air into the cylinder and exhaust means for removing combustion gases from the cylinder: S b. a medium pressure, positive displacement rotary component in integral combination with said reciprocator component, said rotary component having a unitary compressor segment with an air intake and a eS compressed air exit, and an expander segment with a combustion gas exit and a combustion gas intake; c. A Comprex (TM) wave supercharger interposed between the recriprocator component and the rotary component, the supercharger having a compressed air side and a combustion gas side wherein the compressed air side of supercharger communicates with the air exit of the compressor segment and the intake means of the reciprocator component, and the combustion gas side of the supercharger communicates with the exhaust means S. of the reciprocator component and the combustion gas intake of the expander segment; and 30 d. a fuel injection means for injecting fuel into the cylinder of reciprocator component.

Preferred forms of the present invention will now be described by way of example with reference to the accompanying drawings, wherein: KLN/1565b BRIEF DESCRIPTION OF THE DRAWINGS: FIG. 1 is a cross sectional view, partially fragmented of a reciprocal engine with a regenerator lining.

FIG. 2 is an enlarged partial cross sectional view of the regenerator lining for the combustion chamber of the engines disclosed.

FIG. 3 is a cross sectional view of a compound rotary-reciprocal engine with an opposed piston reciprocator unit and .a supercharger.

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0S FIG. 4 is a schematic view of a typical pressure curve i* for a four stroke engine.

FIG. 5 is a cross sectional view of an embodiment of the combustion and drive section of a convertible 2 to 4 stroke engine with S

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dual interconnected pistons and a connected combustion chamber.

FIG. 6 is a schematic view of a compound reciprocal rotary S*..screw engine.

FIG. 7 is a cross sectional view of the combustion and drive section of a single piston, dual crank engine component.

A s; FIG. 8 is a cross sectional view of the engine component of FIG. 7 in combination with a rotary component.

FIG. 9 is a cross sectional view of the combustion and drive section of'an opposed piston dual crank engine component'.

FIG. 10 is a cross sectional view of the engine component of FIG. 9 in combination with a rotary component.

FIG. 11 is a cross sectional view of an alternate arrangement @0 of the engine component of FIG. 9 in combination with a rotary component.

0* 0 o* FIG. 12 is a schematic illustration of a compound *rotary-reciprocal engine with an intermediate pressure wave supercharger.

::rotary-recipr rotary-recipr turbocharger.

0 0 FIG. 13 is a schematic illustration of a compound oal with an intermediate intercombuster.

FIG. 14 is a schematic illustration of a compound ocal engine with an intermediate intercombuster and auxiliary FIG. 15 is a schematic illustration of a compound focal engine with an intermediate pressure wave supercharger rotary-recipr 11 igand auxiliary turbocharger.

FIG. 16 is a schematic illustration of a compound rotary-reciprocal engine with an intermediate pressure wave supercharger, intercombuster and an auxiliary turbocharger.

FIG. 17 is a schematic illustration of a compound rotary-reciprocal engine with an intermediate pressure wave supercharger, intercombuster, auxiliary pressure wave supercharger and turbocharger.

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Y1I L i 1 d i .ie i i ha~A Br _1 I i DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The thermal engines of this invention utilize several novel components in various combinations to achieve superior performance.

When the various components are integrated into the ultimate rotary-reciprocal compound engine designs described, peak pressures and temperatures heretofore unachieveable in a reciprocal engine are developed. The combined components form a unit with a staged expansion to recover maximum work for improved engine efficiencies.

Referring to FIG. 1, a reciprocal engine 1 is shown with S.a unique piston and cylinder arrangement to enable use of a novel cylinder ,'."Jiner 2 for the combustion chamber. The liner 2 forms a regenerative .Vjacket which receives and releases compressed air during the engine :.:::tycle to dynamically insulate the walls of the cylinder 3. In Fig.

an outer engine block 4 is constructed with a working cylinder 3 and a piston 6 reciprocal in the cylinder 3. The piston 6 is connected to a conventional connecting rod 7 and crank 8. A conventional head and monovalve assembly 10 (shown in part) cap the cylinder 3.

o 0 0* The block has. peripheral air intake ports 5 which are exposed when the piston 6 is in the retracted position shown. Combustion gases *.::exhaust through the mono-valve assembly, which with additional valving supplement air intake at an appropriate time in a preferred 2 two-cycle operation of the engine.

The piston is of differential design having an enlarged cap 11 coupled to a central cross-head 12 which is guided in a low temperature guide cylinder 13 in the block 4. The size of the scavenging ports at the bate of the combustion chamber 3 are controlled by a sliding valve 14 which can completely close the ports for operation of the engine in a four stroke mode.

The enlarged cap 11 is fabricated from a strong, high temperature tolerant material such as stainless steel. The cap 11 is constructed with a depending lip 15 that overlaps a projection of the guide cylinder 13 to form a complex sealing passage during the down stroke. In the up stroke the piston cap never contacts the novel cylinder o&liner 2, which is constructed with a series of fins 16 and grooves 17 as shown in the enlarged fragmentary view of FIG. 2.

0:"The cylinder liner 2 is a regenerative cell system that 00 in part functions as a staggered labyrinth sealing system and in part as a thermal regenerator.

o oo In its functions as a thermal regenerator, the liner or regenerative jacket 2 operates by a process based on the penetration, S intake and compression inside the cells 18 of freshly cooled, high pressure air, supplied by an intercooled supercharging system (not shown) All 6 -F r

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during the scavenging process.

In the compression stroke, a part of this air is accumulated and pressurized inside the regenerator cells 18, formed as the piston passes the grooves 17 between the fins 16. The rising piston 6 creates a pressure wave that is increasing. Low pressure admission air in the chamber is forced into the cells of the regenerator. Because each cell has an incrementally increasing pressure, leakage by the advancing edge of the piston is soon absorbed by a lower cell in the pressure cascade.

The trapped air absorbs the thermal energy accumulated in the walls of the regenerator jacket from the previous power stroke. The accumulated S..compressed and heated air in the cells 18 forms an active counter-pressure ,'against the combustion gases escaping during the power stroke.

0S *At the same time in the expansion stroke, the compressed .o:'air accumulated inside the cells 18 expands toward the cylinder space, generating a dynamic, concentric-radial and centripetal flow, which forms an envelope of air surrounding the hot gases, creating a pneumatic 9S*9 insulation between the hot gases and the walls. The heat radiated from S the hot gases is in general the principal source of heat transfer to ocr the cylinder walls. Another effect, perhaps the most important, is the expansion of the compressed air, which on being further heated possess a higher enthalpy, thereby recovering the energy accumulated in the regenerated cell system.

T3, .i This compressed and preheated air is an ideal additive to the combustion process. The air is supplied from the walls of the working cylinder 3 in the final stage of combustion when the concentration of oxygen is reduced. The radial injection of the air to the combustion gases has an additional turbulent effect for aiding complete conibustion.

Finally, the air arid the regenerative cells together form an ideal insulation and an adiabatic shield against the transfer of thermal energy which is normally lost through the cooling system.

Because the piston 6 is a perfect cylindrical body, without 0 .00 "contact with the hot wall zone of the cylinder, lubrication and oil be completely avoided, including all associated mechanical losses.

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The piston is guided in the bottom zone of the cylinder, which is a r i ,:onventional cylinder liner. The bottom zone is lubricated by an air and solid suspension, composed of micro-particulates of graphite and MOS2 (which are injected between the contact surfaces). The same air :K:'nd solid micro-particulate suspension is injected into all of the roller bearings, assuring lubrication and removal of the heat generated in he bearings.

6409 The recollection of the micro-particulates is assured by I. I ,0 group of auxiliary cyclone traps (not shown). The air that is partially expanded and heated by this process is returned to the intercooler of the high stage supercharger for recompression to a final pressure.

O i Alternately, the bottom zone of the cylinder and bearings can be lubricated by conventional means.

In the exemplar of FIG. 1, the engine is a high temperature fuel injected engine with a conventional fuel injector 20 and with unique auxiliary liquid injection nozzles 21 for adding an injected cooling fuel or water in a thermal cogeneration process.

In all the applications of the regenerative jacket 2 a cogeneration thermal process may be added. This process injects a cooling ;'flu'id (methanol, liquid N02, liquified gases, or water) through an 1: *njection system which comprises a series of spaced nozzles 21 around .0 S.the crown 22 of the combustion chamber which direct an arcuate spray 23 down the walls of the regenerator during the brief period that the piston is rising in its compression stroke. A liquid injector 24 feeds the nozzles with liquid, usually water in a measured timed pulse.

.0:Preferably, as shown in FIG. 2, the liquid is preheated by circulating *.1j i a helicoidal passageway 25 between the regenerative jacket or liner 2.and the wall 26 of the block 1.

In embodiments employing a cogenerator using water injection, 0 o i~he fine droplets of water in the spray are directed at the walls of 'I 00 00 the regenerator and are swept into the cells with the packing air.

The high velocity spray mist is drawn into the regenerative cells which cover the walls of the combustion chamber by action of the increasing -rr I chamber pressure as the piston rises.

In the cells the water is vaporized cooling the fins and the vaporized water is released as superheated steam along with the compressed air during the power stroke thereby confining the peak temperature gases of the combustion at the center of the chamber.

The heating, evaporating and the super-heating process is accomplished in the brief time in which the piston is near the top dead point. The flushing of this superheated steam or additional ombusted cooling fluid after the peak combustion time occurs as an 0 0 S'tdmixture to the regular combustion gases as the piston descends. In .:he case of steam, there is associated a Rankine cycle with the *-egenerative, thermal cycle. The homogeneous mixture of combustion gases, superheated steam, and the preheated air expanded from. the regenerative cells, comprises the final working fluid that drives the .*':*piston and any exhaust-powered, auxiliary or integrated component as 0.; *escribed with relation to the other engine embodiments.

fee* Referring to the engine embodiment of FIG. 3, the regenerative thermal engine shown comprises a rotary-reciprocal compound 5* engine with a two stroke, opposed piston component 88 coupled to a rotary piston component 92. The compound engine includes a turbocharger 97 and two intercoolers 96 and 98 between the air compression stages.

A 1 The opposed piston arrangement of the reciprocator component 88 is similar in construction to the engine embodiment of FIG. 1. Opposed differential pistons 6 drive two crank shafts 81 coupled to the pistons by connecting rods 82. Replacing the head and valve assembly of the FIG. 1 embodiment is a simple side mounted fuel injector 89. A compound liner 42 includes a central segment 44 comprising the regenerator 2 and end segments 45 forming scavenging ports 5 and exhaust ports 91.

The rotary piston component 92 is a roto-compound system composed of a compressor staje 93 and an expander stage 94. The cbmpressor stage 93 receives precompressed air from the compressor *side of the turbocharger 97, which is cooled by the intercooler 98.

The precompressed and cooled air is further compressed by the positive .lisplacement compressor stage of the rotary component 92. After cooling by the second intercooler 96, the compressed air passes flap valve and enters the reciprocator component 88 through intake ports 5. The *...erntering air under medium compression is further compressed by the united .*.**compression stroke of the two opposed pistons 6 to a substantially higher f0 than usual compression. Fuel injected through an injector 89 ignites in the small core chamber between the piston heads and generates the extremely high pressures herebefore unattainable in piston engines.

S*"Because the single combustion chamber is centralized, stresses are localized and confined to a cylindrical structure, a configuration best able to withstand the extraordinary high pressures generated.

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7 M The piston cap 11 is of special construction and fabricated from a high strength material such as stainless steel, and is coupled to the central cross-head 12 which reciprocates in the low temperature cylinder guide 13 of the engine block 4. The short connecting rods 82 and heavy duty cranks 81 absorb the high energy thrust of the pistons and enable a' high torque, high r.p.m. operation. Cooling of the cylinder walls by the regenerator is accomplished as explained with reference to FIGS. 1 and 2. The expanding combustio.i gases exhaust through ports 91 and enter the expander stage 94 of the roto-compound system powering the rotary component 92.

The positive displacement rotary component 92 is an **.pitrochoidal-type engine similar in type to -the Wankel engine. While has certain attributes of relative efficiency due to its low inertia, 'rotary operation, it is not effective at high pressures and temperatures because of. sealing problems. However, it is ideally suited to accept Sthe partially expanded gases from the high pressure reciprocator component 0* to the reciprocator component in the proper ratio of rotation for a 000 volumetric exchange that assures a high pressure ratio for the supercharging and a high expander ratio for exhaust gases.

00** The rotary component 92 is provided with a ceramic or an insulated rotative piston 99 and is lubricated and cooled by a graphite/MoS2 dry lubricant supplied pneumatically, to the gear and r o bearing mechanism. The absence of oil and friction between the rotor, piston and the epitrochoidal case prevents any excessive wear at high rotational speeds. Sealing is assured by auto adjusting material of Teflon® type impregnated with graphite and MoS2 on the tips 99.1 of the triangular rotary piston 99. The same material is provided for the lateral sealing 100.

As noted in the summary of the invention, the unification of the medium pressure rotary component with the high pressure reciprocator component enables a high peak pressure to be developed **with only the engine structure in the high pressure zone beinr necessarily *O..'esigned to withstand such high peak pressures. This intimate integration nables a substantial reduction in engine size and weight to achieve desired power output.

FIG. 4 is a schematic illustration of the typical pressure ,,,.curve over a 7200 crank shaft rotation in a four stroke engine. As S*..illustrated only a small band of 700 is associated with pressure exceeding 5 5 37 atm and over half of the remaining cycle pressure is less than 6 atm. By staging the components in an integrated unit that is volumetrically balanced, with each component constructed to withstand *'..'those pressures and temperatures within its operating range, a boost *in the peak pressure can be obtained at the same time a reduction in size and weight is accomplished. For example, a low pressure range can be efficiently handled by a supercharger, a medium pressure range by a positive displacement rotary device, and the high pressure range r o« i handled by a specially.designed reciprocal piston device. An efficient thermoenergetical cascade following the pressure curve can be developed by an integrated engine incorporating these exemplar devices.

In the FIG. 5 embodiment, the regenerative thermal engine shown is a convertible four and two stroke device having, a twin arrangement of pistons 50 with permanent dynamic balance. The pistons have a common and symmetrical cycle, by the fact that they are provided with a central, common combustion chamber 101, connected with two tangential channels 102 to cylinders. The two piston mechanisms are i.~tonnected by a strap 103, which takes the opposed side thrust produced the two counter-rotating crankshafts 81.1 and 81.2. Both 1 ounter-rotating crankshafts are geared outside in a 1/1 ratio, assuring perfect symmetry and synchronism of both movements.

This arrangement totally avoids any side thrust between the piston and the cylinder walls, excluding a major source of mechanical

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losses, and allows a close tolerance to be maintained between the pistons and the regenerator 2.

In the schematic view of FIG. 6, the regenerative thermal 'engine of FIG. 5 is associated with a conventional screw compressor 103 and a screwexpander 104, connected directly on both crankshafts of the mechanism in permanent dynamic balance. The counter rotating shafts of the balanced crank mechanism are ideal for a compound screw o-

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device of the type madeby Lisholm.

The high compressed air is inter-cooled in a heat exchanger 105, and the exhaust gases are transported through the pipe 106 from the cylinder head to the screwexpander 104.

The screwexpander 104, is provided with ceramic counter-rotating rotors and sealed by auto-adjusting elements made from Teflon® impregnated with graphite MoS2.

Referring to FIGS. 7 and 8 the concepts for balanced engine ration disclosed with reference to FIG. 5, are combined in an advanced ".cmpound, rotary-reciprocal engine 108. While the engine embodiment "FIGS. 7 and 8 and the subsequent advanced design embodiments are :a 'ticularly devised to incorporate the regenerator liner disclosed herein (since such designs advantageously eliminate piston side thrust) the constructions have independent merit and may incorporate other exotic ,i 4liners, particularly liners demanding that piston and cylinder wall 0.

we contact be wholly eliminated. The following embodiments, particularly **the schematic arrangements disclosed in FIGS. 12-17, disclose variations of integrated components that are configured to achieve a thermal "*as~rgetical cascade following as closely as practicable idealized pressure cves of the type described with reference to the schematically illustrated curve of FIG. 4, but with substantially elevated peak pressures and temperatures.

In a compound rotary-reciprocal engine of FIG. 12 a single cylinder 110 contains a single reciprocating piston 111. While the piston is shown with external grooves 107 for labyrinth sealing or ring sealing in conjunction with a high temperature cylinder liner 53, it is to be understood that the combustion chamber design is particularly suited for incorporation of the regenerator liner 2 as hereinabefore described.

The large bore, short stroke reciprocator component of the compound engine is designed for high pressures and includes two connecting rods 112 connecting the single piston 111 to two S.**ounterrotating, balanced crank shafts 113. The single cylinder 110 ."has a torrodial adiabatic combustion chamber 114 with a central fuel njector 115. The cylinrer has staggered exhaust ports 116 and scavenging *.:..ports 117.

The counter-rotating gears interconnect the two crankshafts in a symmetrical and synchronous movement. The offset intermediate Sgear 119, engaging one of the crankshaft gears, integrates the rotary component with the reciprocator component. As shown in FIG. 8, the epitrochoidal compressor-expander 92 is integrally coupled to the reciprocator component. The compressor-expander 92 supplies the combusted :chamber of the reciprocal pistons with compressed air, and is ':"'.imultaneously driven by the partially expanded exhaust gases in 2Ad?! i i' the manner previously described.

Referring to the engine embodiment of FIG. 9 a super compact, high pressure reciprocator component 125 is shown. Utilizing the dual rod concept of the embodiment of FIGS. 7 and 8, an opposed piston, single chamber reciprocator is formed with the large bore, short stroke features of the prior embodiment. In this embodiment opposed pistons are arranged in a single combustion chamber 120 with a central liner 122 that preferably is an adiabatic regenerator 2 of the type described. At opposed ends of the combustion chamber are exhaust ports 123 and scavenging ports 124. The dual pistons 111 each have a specially formulated adiabatic cap 121 that preferably comprises a regenerator with cell means such as a micropore structure for absorbing and releasing 'Compressed air and/or pass through liquids and vapors for surface cooling 0 qf the piston cap 121 and the preignition chamber 54 formed by the r.ecessed contour in the cap.

Because the engine embodiment of FIG. 9 is most effectively ,*:perable at extremely high pressures, it is primarily suited as a nigh-pressure-range component to a compound engine, particularly one 0 ,.Jtegrating a rotary component such as the screw of FIG. 6 or perferably the roto-compressor expander of FIGS. 3 and 8.

One arrangement of this compact engine unit is show in i ~IG. 10 which is particularly sized and adapted for use for general Za applications, where the output shafts can be connected to an-appropriate gear box or transmission for separate independent operation. The connection of the reciprocator component 125 above the rotary component 92 is convenient for efficient gas flow, particularly where additional intermediate or auxiliary components are combined to enhance the basic unit. The direct connection connects the compressed air exit port 126 and the combusted gas intake port 127 of the rotary component 92 with the respective intake manifold 128 and exhaust manifold 129 of the reciprocator component 125. A metallic flap valve 95 insures one way passage of compressed gases.

*A second arrangement of the compact engine is the front eg 'O'..And back positioning shown in FIG. 11. The enlarged rotary component 2 with respect to the reciprocator component 125 is particularly useful in reduced atmosphere conditions or where low pressure turbocharging is restricted.

The basic unit of the compound rotary-reciprocal engine can as noted include enhancements to enhance efficiency as illustrated 00 in the schematic illustrations of the FIGS. 12-17.

In the schematic of FIG.. 12 the reciprocator component '125 has an intervening connection with the rotary component 92. The o pressure wave supercharger 130 provides additional compression to the air from the rotary, component before entry to the reciprocator component 7' T .li L and has a tendency to buffer or smooth pressure pulsing from the periodic positive displacement cycling of both the reciprocal and rotary components. The compression side has intercoolers 96 between the rotary component and the supercharger and the reciprocator component. While the particular design of the reciprocator component is the unit of FIG.

11, including the regenerator liners, the combination is intended to include such engine component without exotic liners or other such engine components disclosed herein with reference to this or the following figures, similarly, the rotary component shown is identified as the epihoitroidal type, but described herein, but may also comprise the compound screw compressor-expander previously described or other positive displacement rotary compressor expander of the type disclosed.

In the schematic of FIG. 13, the reciprocator component o. is connected to the rotary component 92 with an intervening ."intercombustion chamber 131 with a compressed air by-pass circuit 132 i0 with a control valve 133 for regulating supplemental air to the intercombustion chamber 131. A thermal recuperator 140, insures that S..the added thermal energy to the exhaust gases is recovered in the air-gas *,*sypply 134. The fuel supply 135 may also include a preheater 136 to

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recover waste energy of the exhaust.

yi In the schematic of FIG. 14, a turbocharger 141 has been '*eadded to the thermodynamic cascade of the arrangement of FIG. 13. The 0 u S'urbocharger effectively utilizes the low pressure expansion gases prior 4v o3 l to exhaust through recuperator 140, to perform low end compression of the.intake air. An intercooler 96 is similarly provided to the compressed air to reduce the volume and temperature added by the compression.

In the scemIatic of FIG. 15, a. Comprex® pressure wave supercharger 130 has been installed between the reciprocator component 125 and the rotary component 92 essentially combining the arrangements of FIG. 12 and FIG. 14 without the intercombustor.

In the schematic of FIG. 16 the intercombuster has been added, which is a bypass circuit 143 that allows use of the rotary component or the reciprocator component independent of the other.

In the schematic of FIG. 17 an additional pressure wave upercharger 130 has been installed between the turbocharger 141 and the positive displacement rotary component 92 to boost compression and smooth the pressure pulsing of the rotary component 92. Power for driving the wave guide supercharger 130 are extracted from the combined output ::rive train of the rotary and reciprocal components which both produce *"positive mechanical work.

00 e'vJ" 00 i flt* A- 'L' 'V B S Each component in the above described thermo-energetical cascade is designed and constructed for performance with the specific range of its operation. Thus only the reciprocator component is designed to withstand peak pressures. The rotary component and other auxiliary and intermediary components are specifically designed for their respective lower pressure operations.

While in the foregoing embodiment of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those f skill in the art that numerous changes may be made in such detail of w ithout departing from the spirit and principles of the invention.

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Claims (1)

1. 28- The claims defining the invention are as follows: 1. A compound rotary-reciprocal engine comprising: a. a high pressure, two-cycle reciprocator component having a single cylinder, with at least one piston reciprocally movable in the cylinder with a predetermined displacement volume, the piston and cylinder forming in part a combustion chamber for combustion of gases, intake port means for Introducing air into the cylinder and exhaust port means for removing combustion gases from the cylinder; b. a medium pressure, positive displacement rotary component In integral combination with said reciprocator component, said rotary component having a unitary compressor segment with an air intake and a compressed air exit in direct communication with said intake port means of the reciprocator component and an expander segment with a combustion gas exit and a combustion gas intake In direct communication with said exhaust port means of said reciprocator component, wherein the intake port means S and the compressed air exit form a compressed air passage and the exhaust port means and combustion gas intake form a combustion gas passage, each passage having a volume less than the displacemewt volume of the reciprocator component; and, c. a fuel injection means for injecting fuel into said cylinder of said reciprocator component. S* 2. The engine of claim 1 wherein the positive displacement rotary component comprises a rotary piston device coupled to the reciprocator component in the proper ratio of rotation for a volumetric exchange that assures a high pressure ratio for compression and a high expansion ratio for exhaust. 3. The engine of claim 2 wherein the cylinder has a wall with an insulator liner and the piston includes means to maintain the piston incrementally displaced from the insulator liner during reciprocation of the piston. 4. The engine of claim 3 wherein said means to maintain the piston z -displaced from the insulator liner comprises a dual crank and dual connecting rod mechanism adapted to eliminate piston side thrust, the piston having two connecting rods connected to two counterrotating crank shafts, said mechanism being dynamically balanced to eliminate side thrust and sized to withstand high piston thrust forces. The engine of claim 3 wherein the reciprocator component has an insulator liner with a labrynth sealing structure for sealing between tthe piston and cylinder. S N: '1490b T! _jp i iiiII C- VC*- I~ I~ I I-I rrr~ 6. The engine of claim 5 wherein the insulator liner is a regenerator liner having cells communicating with the cylinder for periodic admission and release of compressed air. 7. The engine of claim 1 wherein the rotary component comprises a compud positive displacment screw comrpressor, screw expander unit. 8. The engine of claim 1 wherein the rotary component comprises a eempoumd epitrochoidal compressor expander. 9. The engine of claim 1 in combination with an intermediate pressure wave supercharger. The engine of claim 1 in combination with an intermedite intercombuster. 11. The engine of claim 10 in combination wih an auxiliary turbocharger. 12. The engine of claim 11 in combination with an intermediate pressure wave supercharger. 13. The engine of claim 12 in combination with a secondary pressure wave supercharger installed between the turbocharger and rotary component. 14. The engine of claim 1 wherein said reciprocator component includes a second piston opposite said first piston with a common combustion chamber. 15. The engine of claim 14 wherein each piston has two connecting rods each rod having a separate countterrotatng crank shaft. 16. The engine of claim 15 wherein the common cylinder has a regenerator liner. 17. The engine of claim 15 wherein the power output of said reciprocator component and said rotary component are interconnected by a transmission means for uniting power output. 18. The engine of claim 15 wherein transmission has means for varying the interconnection ratios of the power transmission and for connecting and disconnecting the power output. 19. A compound rotary-reciprocal engine comprising: a. a high pressure, reciprocator component including a cylinder with an insulator liner comprising a regenerator liner having cells communicating with the cylinder for periodic admission and release of compressed air, a piston reciprocally movable in the cylinder forming in part a combustion chamber for combustion of gases, intake means for introducing air into the cylinder and exhaust means for removing combustion gases from the cylinder; 1490b L i if s 1 b. a medium pressure, positive displacement rotary component in integral combination with said reciproctor component, said rotary component having a unitary compressor segment with an air intake and a compressed air exit In communication with said intake means of the reciprocator component and an expander segment with a combustion gas exit and a combustion gas intake in communication with said exhaust means of said reciprocator component; and c. a fuel injection means for injecting fuel into said cylinder of said reciprocator component. A compound rotary-reciprocal engine comprising: a. a high pressure, two-cycle, reciprocator component including a sirgle cylinder, at least one piston reciprocally movable in the cylinder foyvming in part a combustion chamber for combustion of gases, intake means for introducing air into the cylinder and exhaust means for removing Q. combustion gases from the cylinder; b. a medium pressure, positive displacement rotary component in integral combination with said reciprocator component, said rotary component having a unitary compressor segment with an air intake and a compressed air exit in direct communication with said intake means of the reciprocator component and an expander segment with a combustion gas exit and a combustion gas intake in direct communication with said exhaust means S of said reciprocator component, wherein the compressor segment has a one-way valve means between the compressed air exit and the intake means proximate the compressed air exit for preventing back flow of compressed air and combustion gas into the compressor segment; and, c. a fuel injection means for injecting fuel into said cylinder of S said reciprocator component. S. 21. A compound rotary-reciprocal engine comprising: a. a high pressure, two-cycle recriprocator component including a single cylinder, at least one piston reciprocally movable in the cylinder *;-forming in part a combustion chamber for combustion of gases, intake means for introducing air into the cylinder and exhaust means for removing combustion gases from the cylinder: b. a medium pressure, positive displacement rotary component in integral combination with said reciprocator component, said rotary component having a unitary compressor segment with an air intake and a compressed air exit, and an expander segment with a combustion gas exit and a combustion gas intake; LjN:1490b 7) -7 k I E j I 3:9 c. A Comprex (TM) wave supercharger interposed between the recriprocator component and the rotary component, the supercharger having a compressed air side and a combustion gas side wherein the compressed air side of supercharger communicates with the air exit of the compressor segment and the intake means of the reciprocator component, and the combustion gas side of the supercharger communicates with the exhaust means of the reciprocator component and the combustion gas intake of the expander segment; and d. a fuel injection means for injecting fuel into the cylinder of reciprocator component. 22. The engine of claim 21 in combination with an auxiliary turbocharger. 23. A compound rotary-reciprocal engine as hereinbefore described with reference to, and as shown in the accompanying drawings. DATED this TWENTY-SEVENTH day of APRIL 1989 Paul MA Patent Attorneys for the Applicant SPRUSON FERGUSON *e I, k 1 KLN:1490b