US3795102A

US3795102A - Double acting, reciprocating hot gas, external combustion cylinder-piston engine

Info

Publication number: US3795102A
Application number: US00346107A
Authority: US
Inventors: E Tusche
Original assignee: MAN Maschinenfabrik Augsburg Nuernberg AG
Current assignee: MAN AG
Priority date: 1972-04-08
Filing date: 1973-03-29
Publication date: 1974-03-05
Anticipated expiration: 1991-03-05
Also published as: SE383382B; DE2217078B2; DE2217078A1; DE2217078C3

Abstract

To provide a compact engine construction in which the operating piston-cylinder units and the associated regenerator, condenser and re-heater units are located closely adjacent, with gas connections of minimum length, the cylinder units are combined into one aligned row forming the longitudinal axis of the engine. The regenerator and condenser units for each of the cylinders are placed in common housings, preferably also of cylindrical shape and size similar to and not less than that of the cylinders such that the central axis of the cylinders and the central axis of the common housings paired therewith are placed in planes perpendicular to the longitudinal axis of the machine. The hot gas connection means are all placed in planes which are perpendicular to the machine axis and the cold gas connection means are inclined at an angle to the plane perpendicular to the machine axis. The re-heaters are preferably formed as a wall of tubes extending in a plane parallel to the longitudinal axis of the machine, the cylinders, as well as the cylindrical housings for the regenerator and condensers being formed with similar manifolds connecting to the re-heater tube wall.

Description

Tusche DOUBLE ACTING, RECIPROCATING HOT GAS, EXTERNAL COMBUSTION CYLINDER-PISTON ENGINE Inventor: Eckhard Tusche, Augsburg,

Germany M.A.N. Maschinenfabrik Augsburg-Numberg Aktiengesellschaft, Augsburg, Germany [73] Assignee:

Filed: Mar. 29, 1973 Appl. No.: 346,107

Foreign Application Priority Data Apr. 8, 1972 Germany 2217078 US. Cl. 60/24 Int. Cl. F03g 7/06, F25b 9/00 Field of Search 60/24 8/1949 Van Weenan 60/24 11/1952 Van Weenan 60/24 9/1970 Bush 60/24 Primary Examiner-Edgar W. Geog hegan Assistant Examiner-H. Burks, Sr. Attorney, Agent, 0r Firm-Flynn & Frishauf [57] ABSTRACT To provide a compact engine construction in which the operating piston-cylinder units and the associated regenerator, condenser and re-heater units are located closely adjacent, with gas connections of minimum length, the cylinder units are combined into one aligned row forming the longitudinal axis of the engine. The regenerator and condenser units for each of the cylinders are placed in common housings, preferably also of cylindrical shape and size similar to and not less than that of the cylinders such that the central axis of the cylinders and the central axis of the common housings paired therewith are placed in planes perpendicular to the longitudinal axis of the machine. The hot gas connection means are all placed in planes which are perpendicular to the machine axis and the cold gas connection means are inclined at an angle to the plane perpendicular to the machine axis. The reheaters are preferably formed as a wall of tubes extending in a plane parallel to the longitudinal axis of the machine, the cylinders, as well as the cylindrical housings for the regenerator and condensers being formed with similar manifolds connecting to the reheater tube wall.

14 Claims, 6 Drawing Figures PATENTEUHAR 5 \974 SNEH 1 Bf 2 Fig.1

DOUBLE ACTING, RECIPROCATING HOT GAS, EXTERNAL COMBUSTION CYLINDER-PISTON ENGINE CROSS REFERENCE TO RELATED APPLICATIONS U.S. Ser. No. 317,778, filed: Dec. 22, 1972; US. Ser. No. 315,930, filed: Dec. 18, 1972 US. Ser. No. 352,711 filed Apr. 19, 1973.

The present invention relates to a double acting piston-cylinder engine of the external combustion, hot gas type and more particularly to such an engine which has a plurality of cylinders located in a row, the cylinders forming the longitudinal axis of the engine.

In engines of this type, the hot space, and the cold space of the cylinder are sub-divided by the working piston. The working piston is connected to a piston rod and the piston rod, in turn, to the usual crankshaft forming the rotary or mechanical output of the engine. The hot space of any one cylinder is connected to the cold space of another cylinder, with interposition of a heater unit, a regenerator, and a cooling unit or condenser. The cooling unit is connected to a line or connection duct which terminates in the cold space of any cylinder other than the hot space of the cylinder which is connected to the re-heater unit.

Hot gas piston-cylinder engines of this type have previously been described. The construction and arrangement of the cylinders, re-heaters, cooler and other components require, usually, comparatively long flow paths for the gases. The comparatively long flow paths leading from one cylinder to another cylinder, between which further cylinders may be disposed, result in a gas volume within the line which may be large with respect to the maximum displacement volume of the working spaces and the cylinders themselves. As a result, high line losses will result, which in turn results in low efficiency of the overall engine construction. A compara tively high volume of working fluid is required in order to fill such an engine. The working fluid may be a gas such as helium and the smaller the overall volume of the engine can be held, with respect to working volume of the pistons, the more efficient will be the use of the gas which is employed in the engine.

It is an object of the present invention to provide a double acting cylinder-piston hot gas multiple cylinder engine in which the components of the engine are so arranged that losses due to long interconnection lines are held to a minimum and which results in improved overall engine operating efficiency.

SUBJECT MATTER OF THE PRESENT INVENTION Briefly, the double acting cylinder-piston units are located all along a line row to form the longitudinal axis of the machine. Any one cylinder is paired with a regenerator and cooler, which are located in a common housing. The longitudinal axes of any one cylinder and of a regenerator and housing paired therewith are located in planes perpendicular to the longitudinal axis of the machine. The flow paths forming the hot lines are arranged parallel to a plane perpendicular to the longitudinal axis of the machine. The flow paths forming the cold ducts are located at an angle inclined to a plane perpendicular to the longitudinal machine axis.

The specific arrangement of the operating cylinderpiston units and the, preferably cylindrical, common housings of the regenerator-cooler units permits construction of an in-line motor with any desired number of cylinders in modular form. Various cylinder-type piston units and common housings for the regenerators and coolers, all similar, can be located next to each other, and assembled together as desired, resulting in a narrow and short overall engine construction. The hot lines are extremely short, since each cylinder has the associated regenerator-condenser placed immediately adjacent thereto, so that expansion of materials, resulting from heating of the construction, will be held to a minimum. Placing the hot lines in a plane perpendicular to the longitudinal axis of the machine also permits easy accessibility to the cylinder-regenerator units facilitating gas-tight connection, initial assembly, and subsequent maintenance.

The invention will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a highly schematic, perspective illustration of an in-line four-cylinder engine in which the regenerator housings are located at opposite sides of the cylinders, in sections;

FIG. 2 is a schematic top view, illustrating the flow paths of the engine of FIG. 1;

FIG. 3 is a schematic top view, illustrating flow paths, of an in-line six-cylinder motor in which the regenerator-cooler units are placed at opposite sides of the row of cylinders, in sections;

FIG. 4 is a schematic top view of an in-line sixcylinder engine in which the regenerator-cooler units are paired, and sectionally located at opposite sides of the cylinder row;

FIG. 5 is a schematic top view illustrating flow paths of a four-cylinder engine in which the regeneratorcooler housings are located on one side of the cylinder row; and

FIG. 6 is a schematic top view illustrating flow paths ofa six-cylinder motor in which the regenerator-cooler housings are located at one side of a cylinder row.

The engine of FIG. 1 has four cylinders l, 2, 3, 4. Each cylinder has a piston 5 therein which sub-divides the cylinder into an upper, or hot working space 6 and a lower or cold working space 7. Each piston 5 is connected to a piston rod 8, schematically shown, which in turn is connected to a crankshaft 9, also shown only schematically. Cylinders l-4 are each connected to a regenerator and a cooler, located in a

common housing

10, 11, 12, 13, respectively.

Housings

10 and 11, associated with

cylinders

1 and 2 are located, as seen in FIG. 1, behind the rear row of cylinders.

Housings

12 and 13 associated with cylinders 3 and 41 are located at the opposite side of the

cylinders

3 and 1. Behind

housings

10 and 11 and behind

housings

12, 13, respectively, a free space will be available in which a burner unit, such as a burner 20 (only one being shown, and this burner being shown schematically) can be located. This arrangement results in a very compact engine in which space is highly efficiently utilized. Cylinders l-4 have longitudinal axes AA. The common housings 10-13 also are cylindrical and have longitudinal central axes B-B. The cylinder axes AA of all the cylinders are located in a plane, perpendicular to the longitudinal axis of the machine. The longitudinal axis of the machine lies in a plane common with the main bearings of crankshaft 9. The arrangement in which'the longitudinal axes AA of the cylinders 1-4 and BB of the common housings -13 are in parallel planes, perpendicular to the machines longitudinal axis results in shortest connecting paths between cylinders 1-4 and the associated housings containing a regenerator and a cooler. Cylinders 1-4, as well as housings 10-13 have, located at their top side, at equal height,

manifolds

14, 15, respectively. These manifolds are joined together. The manifolds 14 associated with cylinders 1-4 are connected to the manifolds associated with housings 10-13 are an array of re-heater tubes 16. The tubes 16, each, are bent in U-shaped form to form a tube wall, in which the gaseous medium for operation of the engine is heated. These tubes thus are the heat exchanger between burner and the heating medium. The tube walls are schematically shown at 17, 18. The housings 10-13 for the regenerator-cooler assembly are cylindrical, and have preferably the same diameter, and the same diameter as cylinders 1-4. Shaping cylinders 1-4 and housings 10-13 to be similar permits construction of the

manifolds

14, 15 to be identical, which substantially reduces costs in manufacture, stocking of repair and replacement parts and assembly costs. The

manifolds

14, 15 need not be identical, however, and need not be joined intermediate their combined lengths. They could also be joined at different locations, for example above the common housings 10-13. Such an arrangementdecreases the volume of the manifolds 15, thus decreasing the dead overall volume of the housings 10-13 and the associated manifold. Decreasing this dead volume improves the efficiency of the engine. Additionally, space is obtained above the cylinders 1-4 to permit better placement of the burner 20. The regenerator-cooler housings 10-13 may have a diameter which is larger than that of cylinders 1-4, resulting in a particularly short and slightly wider, but highly compact overall construction of the engine. The flow paths are extremely short, thus further improving the efficiency of the engine as a whole.

Ducts 19 are connected to the cold space 7 of the cylinders 1-4, each. The ducts cut the axes defined by the planes A-A and BB, that is, are located at an angle with respect to planes perpendicular to the longitudinal axis of the engine and, each, extend to one of the housings 10-13 respectively. Ducts 19 are so placed that, at the most, one of the planes defined by the axes A-A and BB is intersected, resulting in short ducts. Ducts 19 connect the cold space 7 of a first cylinder with the housing containing a regenerator and a cooler, and then with the associated manifold. Connected to the manifold is a wall of tubes, which connects to the manifold of the hot space 6 of another cylinder, for example the manifold of the hot space of the adjacent second cylinder. Thus, for example, hot space 6 of cylinder 1 is connected to the cold space 7 of the cylinder 2. The region of the flow path from the regenerator to the hot space 6 forms the hot portion of the path; the region from the cold space 7 to the cooler forms the cold portion of the flow path.

The working fluid, for example helium, has heat applied thereto as it flows through the heater tubes 16. Burner 20 conducts hot gases to the heater tubes 16, located in the

walls

17, 18. Burner 20 is placed adjacent the wall of tubes 18 and located next to the row of cylinders placed oppositely housings 12 and 13. Burner 20 may, however, be placed differently, for example above

cylinders

3, 4. The flow path of the combustion gases from burner 20 is indicated by the heavy arrow 21. The burner providing heat to wall 17 has been omitted from the drawings for clarity, the direction of flow of combustion gases being indicated by arrow 22. The heater tubes 16 of at least two adjacently placed cylinders form one complete connected tube wall, extending parallel to the longitudinal axis of the machine. This location of the cylinders, and the location of the tube walls faciliates heat transfer from the burner to the Working medium and thus improves the efficiency of the machine as a whole. The several heater tubes 16, preferably, are all of the same length and shape, so that the flow paths of the heated and hot gaseous medium are all of the same length. This results in uniform heat transfer. The heater tubes 16 are thermally highly loaded. Uniform heat transfer from the burner 20 to the working fluid is efficient, and avoids thermal overload of any one of the components in the system.

The flow paths between cylinders 1-4 and the regenerator-cooler housings are schematically illustrated in FIG. 2, which also is used as an indication of the schematic representation of flow path in the subsequent FIGS. 3-6, so that the construction of the engines of FIGS. 3-6 will be clear by analogy of the constructional details shown in FIG. 1 with the schematic representation shown in FIG. 2. In the schematic representation, the hot lines are shown as double lines 23, and the cold lines as chain-dotted lines 24. The hot space 6 of cylinder 1 is connected to the cold space 7 of cylinder 2. Hot space 6 of cylinder 2 is connected to the cold space 7 of cylinder 4. Hot space 6 of cylinder 4 is connected with the cold space 7 of cylinder 3. Hot space 6 of cylinder 3 is connected back to the cold space 7 of cylinder 1. Each of the connections includes a common housing of a regenerator-cooler unit.

The

cylinders

1 and 4 and

housings

10 and 13 associated therewith are connected by short lines, bridging the space between a pair of cylinders. These lines, of course, are the cold lines. An arrangement can also be constructed in which two long lines connect to the

housings

10 and 13, bridging two cylinder distances, the short lines then connecting the remaining

housings

11, 12. The hot lines 23, as can be seen from FIG. 2, are very short and of equal length. This arrangement is provided by placement of the cylinders 1-4 in a plane perpendicular to the longitudinal axis of the machine and likewise placing housings 10-13 in planes perpendicular to the longitudinal axis of the machine. The cold lines 24 are not of equal length. The arrangement is so taken, however, that at most one cylinder is between a pair of connected cylinders, so that the differences in length between the cold connecting line are held to a minimum. The connection of the cylinders also permits roughly parallel placement of all cold lines, without cross-overs, so that they can be assembled and connected easily.

FIG. 3 illustrates a six-cylinder engine. Six cylinders 25 are located in a row. Each cylinder 25 has a common housing 26 associated therewith, each housing 26 including a regenerator and a cooler. The housings 26 are grouped in sections, located at opposite sides of the cylinder row, each section comprising three housings 26. Hot lines 27 again have the minimal length, connecting transversely to the longitudinal axis of the machine. Cold lines 28 are so placed, in accordance with the present invention, that at the most, the distance of two cylinders have to be bridged. The length ofthe cold lines is so distributed, similar to the construction of FIG. 2, that the two outer housings have short cold lines applied thereto, and the inner housings have longer cold lines connected. An alternate construction can also be used, in which the two outer housings have the longer cold lines applied, and the inner housings the short ones.

FIG. 4 illustrates a group of cylinders 29, arranged in a row, in which the housings 31 are placed in sections, each one comprising two such housings, the sections alternating at both sides of the rows of cylinders. Cold lines 32, as discussed in connection with FIG. 3, are so placed that only short cold lines are connected to the two outer housings.

The example of FIG. 4 illustrates a four-cylinder engine in which cylinders 33 are connected by hot lines 34 with respective housings 35, each one containing a regenerator and a cooler. In contrast to FIG. 2, however, the housings 35 are all located on one side of the row of the cylinders 34. The cold lines 36 are distributed as discussed in connection with FIG. 2. FIG. 6 illustrates an in-line six-cylinder engine in which the cylinders 37 are connected over hot lines 38 with housings 39, which are all located on one side of the cylinder row. Cold lines 40, as referred to in connection with the discussion of FIG. 3, are connected such that the cold space of the first and last cylinder of a row is connected to the hot space of an adjacent cylinder. The arrangement can be altered, however, as shown in FIG. 3, in which the cold lines 36 connect the hot space of the first and last cylinder, respectively, with the cold space of an adjacent cylinder.

Various changes and modifications may be made within the inventive concept.

I claim: 1. Double acting reciprocating hot gas external combustion piston-cylinder engine comprising a group of adjacently placed cylinders (1, 2, 3, 4, 25,

29, 33, 37) which are located in an aligned row defining the longitindual axis of the engine, the cylinders being subdivided by the pistons into a hot cylinder space (6) and a cold cylinder space (7); a regenerator and cooler for each of the cylinders and a re-heater (16);

cold gas connection means (24, 28, 32, 36, 40) connecting the cold cylinder space (7) of any one cylinder with the respective cooler, regenerator and re-heater;

hot gas connecting means (23, 27, 30, 34, 38), connecting the regenerator to the hot space of another cylinder and including said re-heater;

a common housing (10, 11, 12, 13; 26, 31, 35, 39)

for the regenerator and cooler;

wherein the common housing (-13; 26, 31, 35, 39)

of a regenerator and cooler is paired with a respective cylinder, and the central axis of any cylinder, and the central axis of any common housing paired with a cylinder are located in planes perpendicular to the longitudinal axis of the machine;

the hot gas connection means (23, 27, 31), 34, 38) are parallel to a plane perpendicular to the longitudinal axis of the machine;

and the cold gas means (24, 28, 32, 36, 40) are inclined at an angle to the plane perpendicular to the longitudinal axis of the machine.

2. Machine according to claim 1, wherein the common housings are sub-divided into sections, one section of the common housings being located at one side of the row of cylinders, with respect to the longitudinal axis of the machine, and another section of the common housings being located at the other side of the row of cylinders. (FIGS. 1,2,3,4).

3. Machine according to claim 2, wherein the two sections are of equal length.

4. Machine according to claim 2 (FIG. 4), wherein the groups of the common housings are alternately arranged at opposite sides of the row of cylinders.

5. Machine according to claim 1 (FIGS. 5, 6), wherein all the common housings (35, 39) are, located in a row at the same side of the cylinders.

6. Machine according to claim 1, wherein the connection means to the cylinder spaces form flow paths and wherein the flow path of gas between two cylinders (14, 25, 29, 33, 37) comprises not more than one additional intervening cylinder.

7. Machine according to claim 1, wherein the hot space (6) of the first cylinder (1) in a row and the hot space of the last cylinder (4) in the row are connected with the cold space (7) of the respective adjacently located cylinder (2, 3). (FIGS. 2, 3, 4, 5).

8. Machine according to claim 1, wherein the cold space of the first and last cylinder in a row communicates with the hot space of the respective adjacently located cylinder (FIG. 6).

9. Machine according to claim 1, wherein the common housings are cylindrical.

10. Machine according to claim 9, wherein the diameter of the common housings are at least as great as that of the cylinders.

11. Machine according to claim 9, including manifolds (14, 15) secured to the cylinders and the common housings to conduct gases to and from the re-heaters wherein the manifolds applied to the cylinders and the common housings are similar.

12. Machine according to claim 1, wherein the hot gas connection means are dimensioned to provide flow paths of approximately equal lengths.

13. Machine according to claim 1, wherein the reheater means (16) of at least two adjacently located cylinders (1, 2; 3, 4) form an essentially continuous wall of tubes extending in planes (17, 18) parallel to the longitudinal axis of the machine.

14. Machine according to claim 13, further comprising burner means (20) located at one side of the wall of tubes (17, 18) opposite to that at which the common housings (10-13) are located, the burner means generating heat to heat the tubes of the wall of tubes and hence the gas operating medium for the engine within the heater tubes.

Claims

1. Double acting reciprocating hot gas external combustion piston-cylinder engine comprising a group of adjacently placed cylinders (1, 2, 3, 4, 25, 29, 33, 37) which are located in an aligned row defining the longitindual axis of the engine, the cylinders being subdivided by the pistons into a hot cylinder space (6) and a cold cylinder space (7); a regenerator and cooler for each of the cylinders and a reheater (16); cold gas connection means (24, 28, 32, 36, 40) connecting the cold cylinder space (7) of any one cylinder with the respective cooler, regenerator and re-heater; hot gas connecting means (23, 27, 30, 34, 38), connecting the regenerator to the hot space of another cylinder and including said re-heater; a common housing (10, 11, 12, 13; 26, 31, 35, 39) for the regenerator and cooler; wherein the common housing (10-13; 26, 31, 35, 39) of a regenerator and cooler is paired with a respective cylinder, and the central axis of any cylinder, and the central axis of any common housing paired with a cylinder are located in planes perpendicular to the longitudinal axis of the machine; the hot gas connection means (23, 27, 30, 34, 38) are parallel to a plane perpendicular to the longitudinal axis of the machine; and the cold gas means (24, 28, 32, 36, 40) are inclined at an angle to the plane perpendicular to the longitudinal axis of the machine.

3. Machine according to claim 2, wherein the two sections are of equal length.

5. Machine according to claim 1 (FIGS. 5, 6), wherein all the common housings (35, 39) are located in a row at the same side of the cylinders.

6. Machine according to claim 1, wherein the connection means to the cylinder spaces form flow paths and wherein the flow path of gas between two cylinders (1-4, 25, 29, 33, 37) comprises not more than one additional intervening cylinder.

9. Machine according to claim 1, wherein the common housings are cylindrical.

11. Machine according to claim 9, including manifolds (14, 15) secured to the cylinders and the common housings to conduct gases to and from the re-heaters (16); wherein the manifolds applied to the cylinders and the common housings are similar.