DE2154714B2 - HEATER FOR A HOT GAS ENGINE - Google Patents

Description

^te 8 heater according to claim 1, characterized in that the U-shaped pipe elements (1, 6, 10, from two straight pipe sections (2, 4.8 J3, 7 21) and a pipe bend (5, 7, 11, 15, 19)

'Ä 8', through -taj

^ «Alloys are built up, -f ^^ existing heat transfer ribs (3,9,12,16,20) ³ If SSr 'according to claim 1 for a hot gas engine with an in-line arrangement of the cylinders, characterized in that the heaters of the e .individual cylinder units are housed next to each other in a single heating tube (36).

Π Heater according to claim 10, characterized that a plurality of combustion chambers (32) are arranged in the heating medium shaft (36).

12 heater according to claim 10, characterized in that that only one combustion chamber (32) common to all cylinder units in the He.zmiuelscha-ht (36) is arranged.

The invention relates to a heater for a hot gas engine, consisting of several U-shaped Pipe elements in which the working medium absorbs heat from one of e.ner's external Heat source supplied heating medium flow from the hot into the cold space of the hot gas engine aut the Ways over a regenerator and a cooler as well as in the opposite direction can flow, wöbe, the one of the two in the flow path of the heating medium? h.tere.joint Pipe legs of each U-shaped pipe element to the hot room and the other Pipe legs connected to the regenerator space

The heater is the heat exchanger on the side of the energy supply in the hot gas engine and has the task of Heat from a heating medium flow, e.g. B. take up combustion gas while cooling the flow of heating medium and to the inner circulatory med. B. helium to deliver. The temperature or energy range of the The flow of heating medium must be used as completely as possible down to the temperature of the circulating medium

^ On the other hand, the heater may only have a limited Large, since the inner space for the circulating medium is a dead space for the hot gas engine means. ,

A heater, also consisting of tubular elements, is shown in DT-PS 8 06 740, for example, unc described. It fulfills the requirements mentioned in the two preceding paragraphs only through a « difficult to manufacture and susceptible to bedtime. Construction. At this famous heater you are U-shaped tubular elements on the circumference of a cylindri see combustion chamber arranged, its one Front side of the external heat source in the form of a burner and the other front side of de Wall of the hot room is formed. The combustion gases initially flow in the axial direction de Combustion chamber and are on the wall de hot room in the direction of the pipe element

deflected For this purpose, a heat shield is required, the durability of which ^{is insufficient under the influence of the combustion gases with a temperature of up to 2000 °} C. Another disadvantage of the known design is that each cylinder of a multi-cylinder hot gas engine in an in-line design has its own burner with all associated auxiliary equipment, such as lut preheaters a fuel atomizer must be equipped separately.

In contrast, the object of the invention is to make the heater so that it is for Hot gas engines with several cylinder units in an in-line arrangement is suitable.

This object is achieved according to the invention in a heater of the type mentioned at the outset in that the pipe legs are arranged next to one another in planes, one pipe leg! of a U-shaped pipe element in each case in a first plane and the other pipe leg in each case in a second plane parallel to the first, and wherein the heating medium flows transversely to the longitudinal axes of the pipe legs and transversely to the planes in which the pipe legs are arranged.

This arrangement of the Rohriemente is the harmful diversion of the heating medium flow by a uncooled component, such as a heat shield, is completely avoided. By eliminating the redirection, the Combustion air fan to overcome less resistance and accordingly requires less drive power. The assignment of the burner or burners to the working cylinders of the hot gas engine is essential more permissive and several working cylinders of an in-line engine can also be supplied by one burner will. In contrast to the situation in the known arrangement of the pipe elements on one Heat expansions in the U-shaped tubular elements under the influence of the in a circle can occur Direction through the heater flowing heating medium and the associated higher temperature unfold freely on the upstream side. This results in an outward curvature of the curved end in Direction of the heating medium flow, the inventive arrangement of the flat tubular grids no Changes in the passage cross-sections between the pipes for the heating medium flow occur more leaves. These passage cross-sections must be strictly adhered to and during operation remain unchanged, since their size determines the heat absorption from the heating medium flow.

Although it is known from DT-PS 8 92 533, the tubes of a heater for hot gas engines on one To design part of their longitudinal extension so that they form a flat tubular grid in this sub-area. These However, design is unsuitable for solving the task at hand, as the overall connection between Two working spaces of the known heating gas engine representing heater is not a flat component, whereby The disadvantages of the design according to DT-PS 8 06 740 are also inherent in this heater.

An equally large heat transfer rate is advantageously achieved for all the pipes involved in that all or, as is known per se from CH-PS 2 76 825, only the pipe legs located in the heating medium flow behind the first pipe grille are provided with heat transfer fins, whereby, as per se known from DT-Gbm 19 22 547, the rib surfaces of the pipe grids that are flowed first are smaller than the rib surfaces of the pipe grilles that are subsequently flowed against . As a result, both in a two-row and a four-row pipe grid arrangement, the same proportion of the energy potential available from the heating medium flow is transferred into the inner circuit in each pipe grid Eii a three-row pipe grid arrangement, in which the second and third pipe grids each only half have as many tubes as the first tubular grille, the same amount of heat is transferred from the first tubular grille as from the two downstream tubular grids.

A better freedom of movement in the design of the ribs is advantageously achieved in that there are three pipe grids, a U-shaped pipe element being arranged next to a pipe element, the pipe legs of which are in the first and third pipe grid levels, the pipe legs of which are in the first and second Pipe grille level, the first, second and third pipe grids being flowed through by the heating means one after the other. The working medium of the inner circuit first flows through the first tubular grating, which can be without ribs, and then alternating from tubular element to tubular element through the second or third tubular grating, the second tubular grating having relatively small and the third tubular grating having relatively large, wide ribs. The outputs of the second and third pipe grids are combined in a collecting channel.

A significant reduction in the inflow area of the heater is advantageously achieved by four Pipe grids are present, each in addition to a U-shaped pipe element, the pipe legs in the first and fourth pipe grating level, a U-shaped pipe element is arranged, the pipe legs stand in the second and third pipe grating level, with the first, second, third and fourth pipe grating successively flowed through by the heating means. The working medium of the internal circuit flows through it first the first and second pipe grids. fed from a common collecting duct, and then that third and fourth pipe grids, the outputs of which are combined in a collecting channel. Through this Arrangement, the height and / or width (pipe grid length) of the heater are smaller than with the arrangement with two pipe grids. With the same height of the pipe grille, the four-row heater has an approx. 30-40% smaller width than the two-row heater, since there are correspondingly fewer pipe legs to a roiir grille belong. With the same width, the four-row heater will be around 10-20% lower than a two-row heater Heater The overall volume of the hot gas engine is increased by reducing the inflow area of the Heater significantly reduced. With the four-row heater, there are considerably larger gaps between the pipes than with the two-tier heater. This allows the heater and the associated Putting the collecting ducts next to each other in a multi-cylinder in-line engine is easier.

As already mentioned, the U-shaped pipe elements are connected to the free ends of their pipe legs Collective channels connected, which for manufacturing reasons with the walls of the hot room or the Regeneratorraumes can advantageously consist of one piece. But you can also just use the Walls of the rooms mentioned.

To increase the heat transfer from the heating medium flow to the ribs, the surfaces of the Heat transfer fins to increase the flow

mung turbulence be advantageously grained.

An economical production of the U-shaped pipe elements is advantageously achieved in that the pipe elements are each composed of two straight pipe sections and a pipe bend. This results in individual parts that meet the requirements of the investment casting process, in particular with regard to core production and storage. The application of the investment casting process allows the use of highly heat-resistant materials that are no longer accessible to kneading or machining. This makes it possible to increase the working temperature or pressure of the hot gas engine with the same service life of the heater elements and thus to increase the power density.

The U-shaped tubular elements can also advantageously be made from drawn tubes made of heat-resistant Wrought alloys may be built up, with any heat transfer fins that may be present being soldered on. Through this bending and deformation of the pipes and thus local overstretching, which can lead to cracks, avoided. The straight pipe limbs enable manufacturing operations to be saved. ^

To ensure that the heat flow from the ribs to the core tube is as uniform as possible, the Heat transfer fins advantageously be shorter on the upstream side than on the downstream side.

A structurally simple common heating medium shaft and a common air preheating system is obtained by having the heaters of the individual cylinder units next to one another in multi-cylinder engines are housed in a single Heizmittelkanal.

In order to even out the application of heat to the heater, it is expedient to place it in the heating medium shaft several combustion chambers can be arranged.

However, the effort involved in controlling the combustion is considerably reduced, if only one for all Cylinder units common combustion chamber is arranged in the heating medium shaft.

In the drawings, exemplary embodiments of the invention and an example of the application of the Subject of the invention shown on a hot gas engine.

F i g. 1 shows a section through a tubular element of a two-row heater along the line I-I in FIG Fig. 3;

FIG. 2 shows an end view of the heater made of tubular elements according to FIG. 1 in the direction of the arrows A in FIG. 1 seen;

Fig.3 shows a plan view of the in Fig.2 illustrated double row heater;

FIG. 4 shows a partial section through two tubular elements of a three-row heater along the line IV-IV in FIG. 5;

Fig.5 shows a plan view of the in Fig.4 illustrated three-row heater;

6 shows a partial section through two tubular elements of a four-row heater along the line VI-VI in Fig. 7;

FIG. 7 shows a top view of the in FIG illustrated four-row heater;

Fig.8 shows a two-tier heater and one Section through the associated collecting ducts and through the upper wall parts of the hot room and the Regenerator room;

FIG. 9 shows a top view of the in FIG illustrated heater;

F i g. 10 shows the inflow surface of the heater according to FIG. 8th;

F i g. 11 shows a three-row heater as well as one Section through the associated collecting ducts and through the upper wall parts of the hot room and the Regenerator room;

Fig. 12 shows a section through a cylinder unit and by the heating system of a hot gas engine with the heater according to the invention;

13 shows a top view of the heating system of a hot gas engine in a four-cylinder in-line arrangement, the cylinder units of which have the cylinder units shown in FIG correspond to the execution shown.

The main component of the two-row heater is a U-shaped tube element 1, which is shown in FIGS. 1, 2 and 3 and consists of a smooth tube 2, a tube 4 occupied with large, narrow heat transfer fins 3 and the tube bend 5. In a departure from the embodiment shown, the tube 2 can also be fitted with small heat transfer ribs. In the case of the in FIG. 4 and 5, there are two types of U-shaped tubular members. One pipe element 6 consists of a smooth pipe 2, a short pipe bend 7 and a pipe 8 which is fitted with small circular heat transfer fins 9. The other pipe element 10 consists of a smooth pipe 2, a medium-sized pipe bend U and a pipe 13 fitted with large, wide heat transfer fins 12. In the embodiment of a four-row heater shown in FIGS. 6 and 7, there are also two types of U-shaped tubular elements. One pipe element 14 consists of a smooth pipe 2, a large pipe bend 15 and a pipe 17 provided with large narrow heat transfer fins 16 offset on one side in flow direction A. The other pipe element 18 consists of a short, flat pipe 8 with small circular heat transfer fins 9 Pipe bend 19 and a pipe 21 fitted with medium-sized circular heat transfer fins 20. The pipes 2 and 4, 2 and 8, 2 and 13, 2 and 17, 8 and 21 each form the legs of a U, the connecting bend of which is passed through the pipe bends 5, 7, 11, 15 and 19 are formed. In all of the heater designs shown in FIGS. 1 to 7, the pipe legs 2, 4, 8, 13, 17, 21 are arranged in rows next to one another in the form of flat pipe grids. The heating means flows in the direction of arrows A perpendicular to the NEN Rohrgitterebe- designated in the two-row design with 22 and 23 (Fig. 3), and perpendicular to the axes of the tube legs 2,4,8,13,17,21 . In the case of the in FIG. 4 and 5, the three-row heater design shown is the first tubular grid level with 22, the second tubular grid level with 23 and the third tubular grid level with 24. 6 and 7, the four-row heater version shown is the first pipe grating level with 22, the second pipe grating level with 23, the third pipe grating level with 24 and the fourth pipe grating level with 25 (Fig. 7)

te denotes In the case of the in FIG. 1, 2 and 3, the two-row heater version shown are the free ends the pipe legs 2 and 4 are each connected to single-flow collecting ducts 26 and 27 (FIGS. 1, 2, 8, 9 and 10). The collecting channel 26 leads to the hot room 28 and the collecting duct 27 leads to the regenerator chamber 29. In the case of the one shown in FIGS Three-row heater design are the free ends of the pipe legs 8 and 13, as in F i g. 11 shown

a double-flow collecting duct 30 is connected, which leads to the regenerator chamber 29. As in the two-row design, the free ends of the pipe legs 2 are connected to a single-flow collecting duct 26 which leads to the hot space 28. In the s in Figures 6 and 7, the four-row Erhitzerausführung tube legs 2 and 8 connected to a double-flow collection channel 31 which leads to the hot room 28th The connection of the pipe legs 17 and 21 to the regenerator space 29 takes place, as in the three-row design, with the aid of a double-flow collecting duct 30. The collecting ducts 26, 27, 30 and 31 consist according to FIG. 1. 2. 6, 8, 9, 10, 11.12 made of one piece with the walls of rooms 28 and 29. However, they can also only be connected to these walls. The tubes 2, 4, 8, 13, 17, 21 are connected to the tube bends 5, 7, 11, 15, 19 and the collecting channels 26, 27, 30 and 31 using the vacuum high-temperature soldering process. The heat transfer fins 3, 9, 12, 16 and 20 can be made in one piece with the tubes 2, 4, 8, 13, 17 and 21, and they are manufactured in an investment casting process. But they can also be soldered onto these tubes, which in this case are drawn from heat-resistant wrought alloys. The surfaces of the heat transfer fins 3, 9, 12, 16 and 20 can be grained to improve the heat transfer. You can, as shown in FIG. 6 using the example of the ribs 16, be shorter on the upstream side than on the downstream side in order to ensure the most uniform possible heat flow to the core tube 17. In the application examples shown in FIGS. 12 and 13, the heating means is supplied by one or more combustion chambers 32 to which the combustion air is supplied by a fan (not shown) via the inlet opening 33 and the air preheater 34, as indicated by the arrows. is fed. The combustion gases occur.

after their heat for the most part via the U-shaped tube elements 1, 6, 10, 14, 18 to the inside have given up the working medium of the internal circuit of the hot gas engine and in the air preheater 34 have warmed the combustion air from the opening 35. The heaters of the individual cylinder units a hot gas engine with an in-line arrangement of the cylinders, as shown in FIG. 13, in a single heating medium shaft 36 are arranged side by side. In the heating medium shaft 36, as in F i g. 1-3, a plurality of combustion chambers 32 can be arranged. However, only one combustion chamber 32 can also be used can be provided per heating medium shaft 36, which is common to several cylinder units. The U-shaped Pipe elements 1, 6, 10, 14, 18 can be in any position to the motor axis 37 via the hot Spaces 28 and above the regenerator spaces 29 are arranged depending on the space available. It is possible, with identical units, formed from the walls of the hot room 28 and the regenerator room 29, the collecting channels 26 and 27 or 26 and 30 or 30 and 31, which represent heat-resistant components, together with one of the described heater types, single and multi-cylinder hot gas engines and to build double-acting hot gas engines. The pipe grid levels 22, 23, 24 and 25 do not need absolutely to be absolutely level. They can also have a slightly curved shape, provided that the Thermal expansions of the U-shaped tube elements 1, 6, 10, 14 and 18 no harmful change in the Passage gaps between the pipe legs 2, 4, 8, 13, 17 and 21 or the heat transfer fins 3, 9 12, 16, 20 result. The pipe bends 5, 7, 11, 15 and 19 do not need J, 5 and 7, as in FIG depicted to be individual pieces. You can also, as shown in FIG. 9 and 10 shown for a tubular grid aui consist of one piece.

6 sheets of drawings «09549/2

Claims (7)

't claims: 1. Heater for a hot gas engine, consisting of several U-shaped tubular elements in which the working medium absorbs heat from a heating medium flow supplied by an external heat source from the hot to the cold space of the hot gas engine by way of a regenerator and a cooler as well can flow in the opposite direction, whereby one of the two pipe legs of each U-shaped pipe element lying one behind the other in the flow path of the heating medium is connected to the hot space and the other pipe leg is connected to the regenerator space, characterized in that the pipe legs (2, 4, 8, 13 , 17, 21) are arranged next to one another in planes (22, 23, 24, 25), with one pipe limb (2, 21) of a U-shaped pipe element (1, 6, 10, 14, 18) each in a first plane (22, 24) and the other pipe limb (4, 8, 13, 17) each lies in a second plane (23, 25) parallel to the first, and the heating means transversely to the longitudinal axes of the pipe limbs and un d flows transversely to the planes in which the pipe legs are arranged. 2. Heater according to claim 1, characterized in that all or only those in the heating medium flow behind the first pipe casting plane (22) lying pipe legs (4, 8, 13, 17, 21) with heat transfer fins (3,9, 12,16,20) are provided, the The rib surfaces of the pipe grids against which the flow is first in each case are smaller than the rib surfaces of the subsequently flowed onto the pipe grille. 3. Heater according to claim 1, characterized in that that three pipe grids are available, each in addition to a U-shaped pipe element (6), whose pipe legs (2,13) are in the first and third pipe grating level (22, 24), a U-shaped Pipe element (10) is arranged, the pipe legs (2, 8) of which in the first and second pipe grid level (22, 23) stand, the first, second and third pipe grids flowing through one after the other by the heating means will. 4. Heater according to claim 1, characterized in that four pipe grids are present, wherein each next to a U-shaped pipe element (14), the pipe legs (2, 17) in the first and fourth Pipe lattice plane (22, 25) are standing, a U-shaped pipe element (18) is arranged, the pipe legs (8, 21) are in the second and third pipe grid level (23, 24), the first, second, third and fourth pipe grids are successively traversed by the heating means. 5. Heater according to claim 1, characterized in that that the U-shaped pipe elements (1,6,10, 14,18) with the free ends of their pipe legs (2,4, 8, 13, 17, 21) are connected to collecting channels (26, 27, 30, 31) which are connected to the walls of the hot Space (28) or the Regerieratorraumes (29) consist of one piece. 6. Heater according to claim 2, characterized in that the surfaces of the heat transfer fins (3, 9, 12, 16, 20) are grained to increase the flow turbulence. 7. Heater according to claim 2, characterized in that the heat transfer fins (16) on the upstream side are shorter than on the downstream side