WO2014111347A1

WO2014111347A1 - Device for converting energy which is contained in a fluid

Info

Publication number: WO2014111347A1
Application number: PCT/EP2014/050494
Authority: WO
Original assignee: ENVA Systems GmbH
Priority date: 2013-01-15
Filing date: 2014-01-13
Publication date: 2014-07-24
Also published as: EP2946106A1; DE102013100378A1

Abstract

A device (1) is described for converting energy which is contained in a fluid, with a housing (2) which has a working chamber (7), an inlet opening (5) and an outlet opening (6), at least two rotors (8) which are mounted rotatably in the housing (2) and have in each case at least two blades (10), wherein the rotational axes (9) of the rotors (8) are arranged axially parallel to one another, and wherein the rotors (8) can be operated in opposite directions and at the same rotational speed, wherein the rotors (8) are mounted in the housing (2) in such a way that an axial play (22) of at least 0.01 mm, in particular of at least 0.05 mm, is maintained at the end surfaces (15) of the blades (10) of the rotors (8).

Description

Apparatus for converting fluid contained in a fluid

energy

The invention relates to a device for converting energy contained in a fluid with a housing having a working space, an inlet opening and an outlet opening, at least two rotatably mounted in the housing

Rotors, each having at least two wings, wherein the axes of rotation of the rotors are arranged axially parallel to each other, and wherein the rotors are operated in opposite directions and at the same speed. The invention also relates to the use of such a device as a turbine.

Numerous devices with a housing, which has a working space, an egg opening and an outlet opening, with at least two rotatably mounted in the housing rotors, each having at least two wings, wherein the axes of rotation of the rotors are arranged axially parallel to each other, and the

Rotors in opposite directions and can be operated at the same speed known. Such devices are commonly used as pumps for conveying gases or liquids

are used and are also under the names

"Rotary lobe pump" or "rotary lobe blower" known. A typical rotary piston engine is known for example from DE 100 37 966 Cl.

Known rotary engines are usually well suited for the conveyance of gases or liquids. For this purpose, rotary engines are often driven by a motor. she So take energy or "consume" energy advantages of rotary engines, for example, their high

Flow rate and - in contrast to reciprocating engines - their low-vibration operation. A disadvantage of rotary engines, however, is that they regularly only a very small

Pressure difference between fluid inlet and fluid outlet can reach. As a result of the small pressure differences arise in rotary engines regularly no high temperature differences. Rotary engines are therefore indeed suitable for the promotion of fluids, but less for

Compression or decompression of fluids.

Nor are known rotary engines as turbomachines, which are not used for the promotion of fluids, but to withdraw energy from a flowing fluid to convert it into mechanical and / or electrical energy. In other words

Although rotary piston engines so far as an energy absorbing

Pump, but not used as an energy-dispensing turbine. This is mainly due to the fact that when operating turbines for thermodynamic reasons, a high temperature and / or pressure difference between inlet and outlet is required in order to achieve high efficiency. However, as previously mentioned, known rotary engines are not designed for high pressure and temperature differences.

The invention is therefore based on the object to design the device described above and previously described in such a way and further, that they as

Turbomachine for energy production, in particular as a turbine, is suitable. In a device according to the preamble of claim 1, this object is achieved in that the rotors are mounted in such a manner in the housing, that at the end faces of the blades of the rotors an axial play of at least 0.01 mm, in particular of at least 0.05 mm, is complied with.

Generally used in rotary engines for the promotion of

Fluids strived for a very low clearance between the wings of the rotors and the housing to a high

volumetric efficiency and high specificity

Delivery quantity (Nm ³ per kWh) to achieve. However, the small clearances have the disadvantage that, with thermal expansion of the rotor, grinding and even blockage of the rotor can occur. Therefore, according to the invention

suggested that the rotors so in the housing

are stored at the end faces of the wings of the

Rotors a Äxialspiel of at least ^' 0.01 mm, in particular of at least 0.05 mm, is maintained. An axial clearance in the range between 0.01 mm and 0.5 mm, in particular between 0.05 mm and 0.2 mm, has proven particularly advantageous. To achieve such an axial clearance, it may be necessary, the wings of the rotors

shorten accordingly. Depending on the type of storage, the axial play can only be present on one side or can be distributed approximately uniformly over both end faces. Axial play is the smallest free space in the axial direction between the end face of the wing and the housing end part. By this inventively quite large axial clearance at the end faces of the wings is achieved that the rotors do not grind on the housing even with very strong thermally induced expansion and not block. A According to the invention adapted device can therefore cope with large pressure and / or temperature differences and is therefore surprisingly even used as a turbine. In a further embodiment of the invention, it is provided that the rotors are mounted in the housing such that a radial clearance of at least 0.01 mm, in particular of at least 0.05 mm, is maintained between the blades of the rotors and the inner wall of the working space. As previously described for the axial play also has an increased

Radial play the advantage that the rotor is at high

Can expand temperatures without dragging or blocking the housing. Particularly advantageous is a radial play in the range between 0.01 mm and 0.2 mm,

especially exposed between 0.05 mm and 0.1 mm. Radial clearance is the smallest free space between the rotor and the inner wall of the working space in the radial direction. This may be the distance between the wing and the inner wall or - if the wings have sealing strips - the distance between the sealing strips and the inner wall.

Another teaching of the invention provides that the two rotors are synchronized by gears, in particular by spur gears with straight teeth. The synchronization by helical gears has the advantage that a very precise

Synchronization of the rotors is reached, whereby the wings of the rotors can mesh very precisely. In addition, a reversal of the direction of rotation is achieved automatically by gears. Due to the straight teeth axial forces are avoided, so that, for example, the use of

Cylindrical roller bearings for mounting the rotors is possible. Preferably, the gears are made of a high quality metal prepared to be tempered at about 180 ° C to 250 ° C. This increases the temperature resistance of the gears and improves the suitability of the device for large pressure and / or temperature differences, such as occur when used as a turbine. The gears may for example be made of the material 18CrNiMo7-6, case hardened and have a ground toothing. These

Alloy may preferably be annealed at about 230 ° and has a hardness of about 55 HRC. She joined

Operating temperatures up to 210 ° C proven.

A further embodiment of the invention provides that the gears with a torque of 75 Nm to 90 Nm,

in particular from 80 Nm to 85 Nm, are tightened. Due to the high torque, the gears are particularly firmly connected to the rotors. This also improves the suitability of the

Device for particularly high loads as in the case of

Operation as a turbine can occur. As advantageous, the use of high-strength screws has the

Strength class 12.9 (nominal tensile strength of 1200 N / mm ² ) proved for the attachment of the gears.

In a further embodiment of the invention it is provided that the housing is designed in several parts and has a parting plane or a housing flange, and that the parts of the

Housing in the region of the parting plane or the housing flange bolted together and / or glued. Alternatively or additionally, the housing can be replaced by a thin

Be sealed flat gasket. In the geometric

Design of the gasket is to ensure that the bolt forces and the associated torques remain small. A device with a multi-part housing can particularly easy to assemble and disassemble, since the access is facilitated in the interior of the housing. By a screw connection can be a particularly reliable

Connection between the housing parts can be achieved.

In addition, the housing parts can be glued, which in addition to a further improvement of the connection, a better sealing of the separation point can be achieved. Suitable screws are made of the material ADW7

X49CrMoVl2-l proved for the higher operating pressures

(Nominal tensile strength Rm from 800 to 950 N / mm ² ).

According to another teaching of the invention it is provided that the housing has a plurality of oil chambers. For this purpose, it is further proposed that seals are arranged between the working space and the oil spaces. Oil chambers serve to accommodate means for lubricating the bearings and the gears such as oil. By means of seals, a separation between the working space and the oil spaces can be achieved, so that the fluid flowing through the device does not come into contact with the lubricant and can remain free of contaminants. The seals can be around

Radial shaft seals with integrated labyrinth openings act. The radial shaft seal can in a

Be used sealing ring housing. In addition, liners can be provided.

A further embodiment of the invention provides that the housing is a sight glass, in particular a sight glass

Borosilicate glass. Through a sight glass, the oil level in the housing, especially in the oil chambers of the

Housing, conveniently controlled without the need to open the entire housing. borosilicate glass is characterized by ^' its high chemical and

Temperature resistance.

According to a further embodiment of the invention

provided that the housing has a Ölbefüllstutzen with a vent screw. Through an oil filler neck and a bleed screw, the housing can be easily filled with oil and vented without the entire housing must be opened for this purpose.

In a further embodiment of the invention is finally provided that the housing has an opening for the passage of a drive shaft. This will continue

suggested that the opening through a seal,

in particular one is sealed. The port provides an interface for power transmission, such as through a drive shaft, between the device and a motor or generator. Through a seal that can

Leakage of lubricant and the onset of

Impurities are prevented. The seal "may be a radial shaft seal

Radial shaft seal can be connected to the housing with a retaining ring. To remove the vapor from the

Wave spacing can be a connection for one

Drainage tube be provided.

The device described above and its advantageous developments are particularly suitable for use as a turbine and in particular for driving a generator for generating electrical energy. Due to the structural features of the

Device is suitable for high pressure and Temperature differences and thus for use as

Turbine. Ideally, the mechanical energy of rotating rotors through a generator in electrical

Energy converted. For example, the device can be used to generate energy in steam or gas networks, since such networks usually have different pressure levels anyway and therefore a reduction of the pressure must be made in some places. At exactly these points, the fluid can be passed through the device described above and the reduction of the pressure used to generate energy can be used. Accordingly, the device can be operated as a relaxation device, which

are arranged, a pressure of a flowing into the inlet opening of the device described above fluid, which, for example, a gaseous working fluid

can represent, reduce and thereby convert at least a portion of the energy released in the pressure reduction by relaxation of the fluid into mechanical energy. In this use, as a working medium both water (especially in the form of water vapor), as well

organic media are used. When using water as a medium, pressure differences of up to 8 bar and temperatures of about 200 ° C have been found to be suitable. With organic media, good results were achieved with pressure differences of up to 5 bar and temperatures of about 160 ° C. The use of organic media can be carried out, for example, in the context of OCR processes ("Organic Rankine Cycle") .The device described above can be used, for example, as a rotary piston machine for the expansion of the fluid, wherein the rotary piston machine, which is also known as Roots blower or Roots blower can be referred to, operates on the principle of external compression, so that the fluid undergoes no relaxation by volume change in the closed working chamber of the rotary piston machine, but is pushed against the system back pressure. The relaxation of the working fluid therefore takes place during

Positive displacement blower, for example, by the exit of the

Fluids at the outlet opening of the device. The device described above and its vorteilha th

Further developments can be used at high pressure differences. Between the inlet and the

Outlet opening of the device may have a pressure difference of at least 5 bar, in particular of at least 10 bar

to be available. Even with pressure differences of 15 bar, the described device has worked reliably.

A further embodiment of the invention provides for the use of the device described above in one of the following networks: steam network, carbonic acid network, compressed air network, and natural gas network.

Accordingly, the fluid may be, for example, water vapor, carbon dioxide, compressed air or natural gas.

The invention will be explained in more detail with reference to a drawing showing only a preferred embodiment. 1 shows a device according to the invention for converting energy contained in a fluid in a perspective view, 2 shows the device according to the invention from FIG. 1 in a sectional view along the section plane II - II drawn in FIG. 1, and FIG

Fig. 3 is a schematic representation of the operation of a device according to the invention for the conversion of energy contained in a fluid. Fig. 1 shows an inventive device 1 for

Conversion of energy contained in a fluid in a perspective view. The device has a housing 2, of which in Fig. 1, only one half is shown. The housing 2 can be divided into two parts along a vertically extending parting plane 3. The parting plane 3 has a plurality of through holes 4, via which the two halves of the housing 2 - can be connected to each other - such as by screws. In addition, the two parts of the

Housing 2 are glued together to increase the tightness of the housing 2 in the region of the parting plane 3. The housing 2 has on its upper side an inlet opening 5 and on its underside an outlet opening 6 (hidden in FIG. 1) for the inflow or outflow of a fluid. In its interior, the housing 2 has a working space 7, which has the shape of two overlapping circles in cross section. In the working space 7, two rotors 8 are arranged, whose axes of rotation 9 extend axially parallel to each other. Each of the rotors 8 shown in FIG. 1 and so far preferred has three wings 10. Each of the wings 10 is equipped at its radially outer region with a sealing strip 11. The sealing strip 11 touches upon rotation of the rotors 8, the inner wall of the Working space 7 and the surface of the other

Rotor 8.

In Fig. 1 it can be seen that one of the two rotors 8 has at one of its ends a drive shaft 12. The

Drive shaft 12 can be led out of the housing 2 through an opening, not shown in FIG. 1, in order to drive there a generator (not shown in FIG. 1). The connection to the generator can be generated via a tongue and groove connection, for which purpose the drive shaft 12 has a groove 13. The rotors 8 have at both ends adjacent to the wings 10 cylindrical portions 14. The wings 10 of the rotors 8 have end faces 15, which are flat surfaces which run perpendicular to the axis of rotation 9 of the respective rotor 8. The cylindrical portions 14 serve to support the rotors 8 in the housing 2

Housing 2 also has an oil filler neck 16 with a vent screw 17 and a sight glass 18 for checking the oil level (only shown in Fig. 2).

FIG. 2 shows the device 1 according to the invention from FIG. 1 in a sectional representation along the sectional plane II-II drawn in FIG. Fig. 2 thus allows a view from above into the housing 2 inside. The features of the device 1 already described in connection with Fig. 1 are provided in Fig. 2 with identical reference numerals. The housing 2 is formed in four parts in Fig. 2 and comprises the two at the

Parting plane 3 connected parts 2.1 and 2.2 and the two end-mounted parts 2.3 and 2.4. Both rotors 8 are mounted side by side in the housing 2, wherein the

Rotary axes 9 of the two rotors 8 are arranged axially parallel. The rotors 8 are rotatable about bearings 19 in the housing 2 stored. The bearings 19 are arranged on both sides of the wings 10 on the cylindrical portions 14 of the rotors 8 and are supported on the housing 2. In addition to the bearings 19 seals 20 are arranged. By the seals 20 is formed in the housing 2 on both sides of the working space 7, an oil chamber 21 which contains oil 19 for lubrication of the bearing. The

Seals 20 prevent oil from entering one of the oil chambers 21 in the working space 7. Between the end faces 15 of the rotors and the immediately adjacent components, in this case arranged next to the seals 20

Housing end faces, an axial clearance 22 is formed. In a corresponding manner, a radial clearance 23 is formed between the blades 10 of the rotors 8 and the inner wall of the working space 7.

The drive shaft 12 of the rotor 8 shown in Fig. 2 above is led out through an opening 24 from the housing. In the region of this opening 24, a seal 25 is arranged, which the housing 2 with respect to the rotatably mounted

Drive shaft 12 seals. At the opposite end of the drive shaft 12, each rotor 8, a gear 26. The two gears 26 are identically constructed and interlock, so that both rotors 8 are operated at the same speed and opposite direction of rotation. By the gears 26 so both rotors are the eighth

synchronized.

Finally, FIG. 3 shows a schematic representation of the mode of operation of a device 1 according to the invention for converting energy contained in a fluid. Again, features of the device 1, which have already been described in connection with Fig. 1 and / or Fig. 2, with provided identical reference numerals. In operation, the rotors 8 of the device 1 rotate as shown by the arrows in FIG. A fluid, ie a gas, a vapor or a liquid, is pressed into the housing 2 due to a pressure difference through the inlet opening 5 and causes the rotors 8 to rotate. In the further course ^'is the fluid between two adjacent vanes 10 of the rotor 8

further enclosed by the housing 2 pressed.

Finally, the fluid is pushed out of the housing 2 through the outlet opening 6.

Claims

P a n t a n s p r e c h e

Device (1) for the conversion of into a fluid

contained energy with

- A housing (2) having a working space (7), a

Having inlet opening (5) and an outlet opening (6),

- At least two in the housing (2) rotatably mounted

Rotors (8) each having at least two wings (10),

- Wherein the axes of rotation (9) of the rotors (8) are arranged axially parallel to each other, and

- Where the rotors (8) in opposite directions and with the same

Speed are operable,

characterized in that

the rotors (8) are mounted in the housing (2) such that at the end faces (15) of the blades (10) of the rotors (8) an axial clearance (22) of at least 0.01 mm,

in particular of at least 0.05 mm.

Apparatus according to claim 1, characterized

in that the rotors (8) are mounted in the housing (2) in such a way that between the vanes (10) of the rotors (8) and the inner wall of the working space (7) a radial play (23) of at least 0.01 mm,

in particular of at least 0.05 mm.

Apparatus according to claim 1 or 2, characterized

characterized in that the two red '°' ^J Gears (26), in particular by spur gears with

Straight teeth, synchronized.

Apparatus according to claim 3, characterized

characterized in that s the gears (26) with a torque of 75 Nm to 90 Nm, in particular from 80 Nm to 85 Nm, are tightened.

Device according to one of claims 1 to 4, characterized in that the housing (2) is designed in several parts and a parting plane (3) or a

Has housing flange, and that the parts of the housing (2) in the region of the parting plane (3) or the

Housing flange bolted together and / or

are glued.

Device according to one of claims 1 to 5, characterized in that the housing (2) has a plurality of oil chambers (21).

Apparatus according to claim 6, characterized

in that the seals (20) are arranged between the working space (7) and the oil spaces (21).

Device according to one of claims 1 to 7, characterized in that the housing (2) a

Sight glass (18), in particular a sight glass (18)

Borosilicate glass.

Device according to one of claims 1 to 8, characterized in that the housing (2) has a Has oil filler neck (16) with a bleed screw (17).

Device according to one of claims 1 to 9, characterized in that the housing (2) has an opening (24) for the passage of a drive shaft (12).

11. The device according to claim 10, characterized

characterized in that the opening (24) is sealed by a seal (25)

12. Use of a device (1) according to one of claims 1 to 11 as a turbine.

Use according to claim 12 for driving a generator for generating electrical energy.

Use according to claim 12 or 13, wherein as

Working medium can be used water or organic media.

Use according to any one of claims 12 to 14, wherein

between the inlet opening (5) and the

Outlet opening (6) of the device (1) a

Pressure difference of at least 5 bar, in particular of at least 10 bar is present.

16. Use according to one of claims 12 to 15, wherein the device is operated in one of the following networks:

Steam network,

Carbonated network

Compressed air network, and Natural gas network.