RU2675639C2 - Rotor screw machine - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building and can be used in steam and pneumatic drives, compressors, internal and external combustion engines. Rotor screw machine comprises an axisymmetric rotor 1 with multiple-thread screw channels 3, at least one, which are cut on the rotor 1 around the ring, from different ends are connected to the high and low pressure branch pipes 5 and 6 and tightly blocked by the housing 7 and the movable separating flaps 2. Flaps 2 are fixed on the closed flexible chains 9 links, at least one, moving crosswise to the channels 3 in the located in the housing 7 grooves 11. Channels 3 are cut on the rotor 1 any or all of the outer, inner, and end surfaces, and are individual or combined expansion and compression stages.

EFFECT: invention is aimed at increase in the compression degree, increase in the productivity.

10 cl, 6 dwg

Description

The invention relates to volumetric type machines and can be used to create steam and pneumatic drives, compressors and internal engines (ICE) and external, external combustion.

Known RVM having a cylindrical rotor with helical multi-start working channels, which are arranged in a ring and connected from different ends to the nozzles of high and low pressure and are tightly blocked by a casing and dividing dampers installed opposite, cross-rotor on dividing sprockets with the possibility of rotation. This RVM is used as a compressor, and all channels are involved in the work, and in one stage of compression the pressure is increased up to 25 times. The dampers move along the working channels and compress the gas, the working fluid. The common low-pressure nozzle serves to supply the working fluid to the channels, and two high-pressure nozzles serve to discharge the compressed working fluid and are located on the opposite side of the rotor in front of the dividing flaps in the zone of the beginning of the working channels. Thanks to the opposite installation of the dividing dampers, the radial forces on the rotor are fully compensated. [Mikhailov A.K., Voroshilov V.P. Compressor machines. M .: Energoatomizdat. 1989, p. 221, Fig. 7.17].

The disadvantages of this RVM are:

- low compression ratio and performance;

- a small circle of applicability and inadequacy of RVM for integration into units;

- large uncompensated axial forces and large friction forces between the shutters and the rotor.

Closest to the proposed invention in terms of technical nature and the achieved result, the prototype is a PBM having an axisymmetric rotor made in the form of a flat disk with helical multi-start working channels that are cut inside a ring formed on the surface of the rotor from at least one of its sides are connected from different ends to the nozzles of high and low pressure and are tightly closed by the body and movable dividing dampers installed opposite, cross to the rotor, on the dividing x sprockets, with the possibility of rotation [Patent US №2010 / 0003153 A1, 07.012010, F04C 18/16]. This RVM is also used only as a compressor, but differs from the analogue in that the rotor has flat rings with working channels on one or both sides of the disk. Here, due to a decrease in the diameter of the channel as the valve moves and, accordingly, a larger suction volume, a higher compression ratio is achieved. The compression ratio is defined as the ratio of the initial, sucked-in volume to the final [Mechanical Engineering Manual, Volume 2. M.: Mashgiz. 1961, p. 79.] the volume of compressed gas at the time it began to be pushed out. The compression ratio is a geometric characteristic of the machine. In the case of a double-sided arrangement of rings with working channels, the axial forces on the rotor are compensated, and the performance of the PBM doubles.

The disadvantages of this RVM are:

- low compression ratio and low productivity;

- the prototype is used as a compressor, respectively, has a small circle of applicability and is not suitable for installation in units;

- large friction forces between the shutters and the rotor.

An object of the invention is to increase the degree of compression, increase productivity, expand the range of applicability of RVM, including due to the possibility of compact integration into units and use in power cycles, and reduce friction in a pair of shutter - rotor.

The essence of the invention lies in the fact that in a rotary screw machine having an axisymmetric rotor with helical multi-start working channels, at least one that are cut inside the ring formed on the surface of the rotor, are connected from different ends to the nozzles of high and low pressure and are tightly closed housing and movable dividing dampers, it is proposed to fix dividing dampers on the links of closed flexible chains of at least one cross-moving channels in the grooves located in the housing it is necessary, moreover, the expansion and compression stages formed inside the rings by working channels are proposed to be cut into any or all of the external, internal and end surfaces of the rotor and include these stages separately, or by combining them.

In this case, in contrast to the fastening of the shutters in the prototype on rotating dividing sprockets entering the rotor body along an arc of a limited size, the proposed technical solution - fixing the shutters moving crosswise to the channels in the grooves on the chain links, removes the restriction on the length of the shutter path and the size of the ring on the surface rotor, inside which the working channels are cut. This provides a larger working volume allocated by the dampers and, accordingly, increases the productivity of the RVM and the compression ratio in the RVM.

The second proposed technical solution - the location of the individual or combined expansion and compression stages with working channels that are cut inside the rings on any or all: the outer, inner and end surfaces of the rotor, allows you to create compact machines with an increased number of placed steps on one rotor and this ensures the following technical result:

- Improving the performance of RVM with parallel connection of steps. This connection allows you to create a compact high-performance compressor and a powerful small-sized expansion machine with a large flow rate of the working fluid (steam, compressed air).

- Increasing the degree of compression of the RVM when connecting the steps in series. This connection allows you to create a compact multi-stage high-pressure compressor or a multi-stage small-sized expansion steam high-pressure machine. For example, at the TPPs working on the Rankine cycle, the degree of expansion of the steam (compression ratio) reaches 6000 or more times [Puzyrev EM Golubev V.A. Puzyrev M.E. Rotary screw engines. News of Tomsk Polytechnic University. Tomsk, 2014, v. 324, p. 38-45], and it is provided in steam turbines with two to three expansion stages, each having several tens of impellers with blades. The same degree of expansion can be provided in one RM with three stages of expansion with their rather small degree of compression: (6000) ^1/3 = 18.2.

- Expanding the range of applicability of RVM due to the possibility of including stages of RVM with the formation on their basis of machines working on different power cycles. Specifically proposed:

1. Use RVM with expansion and compression stages as a turbocharging unit for operation as part of an internal combustion engine. The high-pressure pipes of the expansion and compression stages are connected respectively to the exhaust and the air supply path to the internal combustion engine. In this case, compressed air is supplied to the internal combustion engine, due to the work of the expansion of exhaust gases. Currently, turbocharging is the most effective system for increasing engine power without increasing the speed and volume of the cylinders, provides fuel savings per unit of power and reduced exhaust gas toxicity due to more complete combustion of the fuel.

2. Use RVM with expansion and compression stages as an independent internal combustion engine in a gas turbine (GTU) type cycle when connecting the compression stage to the expansion stage through the combustion chamber. With this connection, the compressed air in the compressor is then heated in the combustion chamber, receiving fuel energy, and then gives it to the expansion stage, doing the work.

3. Use RVM with expansion and compression stages as an internal combustion engine, when connecting compression stages to expansion stages with the installation of spark plugs and / or fuel injectors in the working channels behind the supply pipes in high-pressure zones. After the compression stage, air and fuel in the form of a charge of the air-fuel mixture are sealed in the high pressure zone of the expansion stage and ignited. Further, the combustion products expand, doing the expansion work.

4. Use RVM with stages of expansion and compression in cycles of the Rankine type with an organic working fluid (ORC). In this case, the compression stage is connected by high pressure pipes to the regenerator (heat exchanger), then to the hot heat exchanger and to the high pressure pipes of the expansion stage. After completing the expansion work, the working fluid is cooled in the regenerator and the cold heat exchanger, discharging unused heat, returns through the low pressure pipes to the compression stage, circulating along the circulation circuit of the working medium - the compression stage, regenerator, hot heat exchanger, expansion stage, regenerator and cold heat exchanger.

In all these cycles, the RVM is made with expansion and compression stages, and it works as an engine. The compression stage is used to prepare (compress) the working fluid, and in the expansion stage it gives off energy, doing the work. At the same time, the expansion and compression stages or their pairs are located on the common rotor, providing compactness and a wide range of applicability of the proposed device.

Note that here is another important technical solution. It is proposed to arrange the expansion and compression stages on the common shaft in pairs, and counter to one, and perform the steps with the same type of rings in the form of a cylindrical, conical, round or other shape when placing a zone of high pressure or rarefaction in the center of the rotor. This design of the RVM provides mutual compensation of the axial forces on the rotor and the ease of connecting the steps to each other in the center of the rotor due to the close location of their pipes of the same name.

This technical solution is applicable for pairs of steps of the same or different types. For example, this gives a simple design of the unit for connecting the RVM stages with a common high-pressure nozzle in the center of the rotor when two compressor stages are connected in parallel to the compressed air path or expansion machines to the steam line. Similarly, it is structurally easier to connect the compression stage to the expansion stage by common high-pressure pipes, positioning it in the center of the rotor.

The simplicity of the design of the high pressure connection unit in the center of the rotor is that in both cases there is no need to install complex end seals of the high pressure rotor.

Other proposed additional technical solutions relate to the working channel - damper system.

Firstly, an additional sign of the location of the grooves and dampers is introduced orthogonally (perpendicularly) with respect to the channels. With this arrangement, the pressure force acting on the flaps is directed parallel to the walls of the channels; it does not press the flaps against the walls of the channels. Accordingly, the friction force of the shutters against the channel walls is minimized, since it is proportional to the force pressing the shutters against the channel walls.

The next group of technical solutions proposes to increase the working volume of the channels and increase the degree of compression of the PBM by increasing the cross section of the working channels as they move away from the high-pressure pipe.

It is proposed to provide an increase in the cross-sectional area of the working channels due to gradual deepening, and their overlapping by shutters is achieved by installing flexible chains with an inclination to the rotor surface, and shutters are proposed to be made as continuations of chain links. At the same time, due to the same angle of inclination of the bottom of the channels and the circuit, the working channels are sealed by shutters.

Secondly, it is also proposed to increase the cross-section of the working channels by expanding them, and for their reliable overlap, it is proposed to install seals on the flaps that are capable of changing their width due to movable sealing elements that are moved apart by the springs.

In addition, it is proposed to install seals on the shutters made of elastic, heat-resistant sheets with an anti-friction wear-resistant coating having the ability to expand and contract. Such seals provide:

- tightness of the overlap of the working channels when they expand due to elastic forces and pressure drop;

- reliable operation of the RVM in the above-described high-temperature cycles of 1-3 ICE and gas turbine due to the use of heat-resistant sheets and compensation of thermal expansions by them;

- reduction of friction forces and reliable operation due to the use of antifriction, wear-resistant coatings.

The indicated features and technical solutions are essential and interconnected causation with the formation of a set of essential features necessary and sufficient to achieve the specified technical results.

As a result, the totality of the proposed technical solutions in comparison with the prototype provides the claimed characteristics: increased compression ratio; increase in productivity; expanding the range of applicability of RVM, including due to the possibility of compact integration into units and use in power cycles and reducing friction in a pair of shutter - rotor.

The design of the proposed RVM is illustrated by drawings. In FIG. 1 in isometry schematically shows the simplest version of the movable elements of the RVM with one stage, the expansion stage. In FIG. 2 shows a RVM with two stages, the working channels of which are cut on both sides of the rotor, made in the form of a disk. In FIG. Figure 3 shows a RVM with two steps, which are located on a rotor of complex shape, providing a reduction in the dimensions of the RVM by reducing the diameter of the rotor. In FIG. 4 shows a six-way channel cutting on the rotor ring, made in the form of a disk for the expansion or compression stage, and the main elements for the ICE stage. In FIG. 5 shows the design of the seals of the separation flaps. In FIG. Figure 6 shows an example of the use of RVM in the ORC cycle.

The PBM has an axisymmetric rotor 1 and dividing shutters 2 that overlap the working channels 3, FIG. 1. Here, the working channel 3 is single-entry and is formed by one screw partition 4. The working channel 3 is connected from different ends to the high-pressure pipe 5 and the low-pressure pipe 6 and is tightly closed by the housing 7, and the rotor 1 is mounted on the shaft 8. In FIG. 1, the upper part of the housing 7 is shown transparent and shows in isometric spiral channels 3, a closed flexible chain 9 formed by its links 10 and moving along the groove 11, which is located in the housing 7. The cross section of the channels 3 is made expanding as they move away from the pipe 5 high pressure due to their gradual deepening by installing chains 9 with an inclination to the surface of the rotor 1, and the dividing flaps 2 (here for clarity, they are highlighted by a crosshair) are made as a continuation of the links of 10 chains.

The rotor 1 may have a different geometry, suitable for embedding RVM in units and providing their increased compactness, which is especially important, for example, for working in transport RVM. For the example of FIG. 2 shows a disk, on both sides of which a working channel 3 is cut along a ring, in this case flat, and two stages are placed. As in FIG. 1, here the working channels can be made with a gradual deepening.

In FIG. 3 shows a section of a PBM with a rotor 1, which is partially made in the form of a cone. Working channels are cut on one or both sides of the rotor, in this case the rings are made of round and conical, and by reducing the diameter of the rotor, the dimensions of the PBM are reduced, which is important for its compactness and integration into the units. In the same way, a cylindrical rotor can be used with cutting working channels on the outer, inner, or on both sides along circular rings, as well as on flat rings along the ends of the cylinder.

Together with the possibility of using individual rings or their groups in compression and expansion stages, the PBM can be used as a single device in power cycles, typically including compression and expansion processes, which significantly expands the range of applicability.

In FIG. 4 schematically shows a six-way cutting of screw channels 3 on a flat rotor 1. Here, as in FIG. 2 and 3, a pair of closed circuits 9 with dividing dampers 2, overlapping screw channels 3, is installed opposite, and this compensates for lateral forces on the rotor. In addition, a pair of closed circuits 9 provides a twofold increase in the productivity of the PBM by increasing the number of inlets of the working fluid per revolution of the rotor 1, in this case there will be 12 inlets per revolution.

In FIG. 4 chains 9 are located orthogonally (perpendicularly) with respect to the working channels 3 due to the required execution of the grooves 11 guiding the flexible chains. This ensures that the pressure forces are directed to the dividing shutters 2 parallel to the screw partitions 4. The pressure acting on the dividing shutters 2 does not press them against the screw partitions 4, and this minimizes the friction force between them.

To reduce leakage of the working fluid on the separation flaps 2, especially in the variant of the expanding working channels 3, seals are installed, FIG. 5, which can be made of having the ability to expand and contract elastic, heat-resistant sheets 12 with antifriction, wear-resistant coatings. The seal design may also use springs 13, which press the movable elements of the seals 14 against the walls of the expanding screw channels 4.

The dividing flaps 2 and the screw partitions 4 are engaged and can only move in concert. The stages of expansion and contraction have, in principle, the same device and are reversible, depending on the direction of movement, the purpose of the stage changes. In the expansion stage, compressed gas or steam enters through a pair of high pressure nozzles 5 installed in the housing 7, expands in the working channels 3, rotates the rotor 1 and moves the closed circuit 9, as shown by arrows 15, and is discharged along the rotor periphery to the low pressure nozzle 6 FIG. 1. In the embodiment of the compression stage, the closed circuits 9 and the rotor 1 have opposite directions of motion and are driven into rotation by the engine or from the expansion stage of the PBM through their common shaft 8.

When using the expansion stage of the RVM as an internal combustion engine, FIG. 4, it has high-pressure nozzles 5, as well as fuel injection and ignition devices 16. They spray fuel and, if necessary, supply an ignition spark to the initial volume 17 of compressed air, the volume is shown by shading by FIG. four.

In a power cycle operating computer, both an expansion step and a compression step are necessary, and they can be located on one rotor on different sides thereof, as shown in FIG. 2 and 3, or on a common shaft 8, FIG. 6, and with mutual compensation of axial forces. Since turbo-boosting in ICE, gas turbine engine and in other cycles has a higher flow rate and requires a greater degree of expansion of the hot working fluid than the flow rate and degree of air compression, the circuit shown in FIG. 3, with the layout of the compressor inside the rotor, and the expansion stage outside. The schemes for connecting the expansion and compression stages of the PBMs to each other depend on the type of power cycles, known and discussed below.

When using RVM as a turbocharging unit, the high-pressure pipe of the expansion stage is connected to the exhaust of the external internal combustion engine, and the high-pressure pipe of the compression stage is connected to its inlet. At the same time, low-pressure pipes of both stages of the PBM are connected to the atmosphere.

When using RVM in the gas turbine cycle, the low pressure pipes of both stages are connected to the atmosphere, and the high pressure pipe of the compression stage is connected to the high pressure pipe of the expansion stage through the combustion chamber into which the fuel is supplied.

In the ICE cycle, the steps have the same connection, but there is no combustion chamber, fuel is injected and ignited in the initial volume 17 by the fuel injection and ignition device 16.

In more detail in FIG. 6 shows a diagram for the ORC cycle. The compression stages 18 and expansion 19 are installed on a common shaft 8 and the pipelines 20 are combined into a closed circulation circuit of the working fluid, which includes: a heat source 21, an exhaust heat regenerator 22, an intermediate recovery heat generator 23 with an expansion stage 19 with a selection pipe 24, and a cold heat exchanger 25 .

Work RVM. When operating a PBM, for example, as a compression stage, the movable elements of the PBM rotor 1 and the dividing shutters 2, due to their fastening on the links 10 of the flexible chain and meshing with the screw partitions 4, which form the working channels 3, move synchronously and rotate the closed flexible chain 9 in the grooves 11. Moreover, the flexible circuit in the compressor moves against the direction of the arrow 15. The distance in the channel between the dividing flaps 2 decreases as the rotor rotates and moves away from the low pressure pipe 6. The working fluid located in the working channels 3 due to their compaction due to the overlap of the housing 7, is compressed. With the approach of the ends of the working channels 3 to the nozzles 5 of high pressure, FIG. 4, the outlet for the compressed gas opens, and the working fluid is forced out of the compressor by the dividing dampers 2 through them in a compressed form.

The principle of operation of an expansion type RVM, including with an increasing cross section of working channels 3, FIG. 1 and 5, and accordingly with a higher compression ratio, does not change. The rotor 1 with working channels 3 slides along the housing 7 with high-pressure nozzles 5 with tight contact of the screw partitions 4 with it, FIG. 4. In the screw channels 3 expansion stages during their opening, alignment of the holes, portions of the compressed working fluid through a pair of nozzles 5 high pressure. Another embodiment for supplying a compressed working fluid is shown in FIG. 1. After turning and exiting the working channels 3 from the connection to the high-pressure nozzles 5, the portions of the working fluid cut off by the dividing flaps 2 fill the shading shown in FIG. 4, the initial volume 17, expand, put pressure on them, and the screw partitions 4 rotate the rotor 1 and do the useful work of expansion. Moreover, in the ICE cycles, fuel is preliminarily sprayed into the initial volume 17 of compressed air and, if necessary, an ignition spark is supplied from device 16 — the heat of combustion of the fuel is introduced. After completing the work, the expanded working fluid through the low pressure pipe 6 is discharged into the atmosphere or returns to the cycle.

Seals on the dividing flaps 2, FIG. 5, reduce the leakage of the working fluid, which is especially necessary in the version of the expanding working channels 3. Seals using springs 13 press the movable elements 14 against the partitions 4 of the expanding working channels 4 and tightly overlap the cross section of the working channels 3. Seals made of elastic, heat-resistant sheets 12 with anti-friction, wear-resistant coatings, not only expand and contract, tightly overlapping the cross section of the working channels 3, but also perceive the high-temperature effects of fuel combustion products and reduce forces s friction. In this case, the movement of the dividing flaps 2 is orthogonal with respect to the working channels 3, FIG. 4, and anti-friction seal coatings reduce friction.

The action of RVM in power cycles is to obtain expansion work from the working fluid in the processes carried out in the expansion step. According to FIG. 4, into the working channels 3 of the expansion stage during the period of their opening and alignment of the holes, portions of the compressed working fluid enter through a pair of high-pressure pipes 5, respectively:

- from the exhaust chamber of an external internal combustion engine - in a turbocharging unit;

- from the combustion chamber - in the cycle of gas turbine;

- from the stage of air compression - in ICE cycles;

- from a hot heat exchanger and regenerators - in the ORC cycle.

Next, the compressed hot working fluid (combustion products) expands, performs work and rotates the rotor 1 and the shaft 8 of the RVM, and in the ICE cycles in the initial volume 17 from the device 16, fuel is pre-sprayed in compressed air and, if necessary, a spark is supplied - the heat of combustion fuel. Due to the common rotor or mounting on a common shaft 8, the expansion stage 19 rotates the compression stage 18. The working fluid or fresh air is sucked through the low pressure pipe 6 into the compression stage 18, is compressed by the shutters 2 in the working channels 3, is pumped into the high pressure pipes 5 of the compression stage and served:

- on the intake of the internal combustion engine - in the turbocharger;

- to the combustion chamber - in the cycle of gas turbine;

- to the high pressure nozzles of the expansion stage - in ICE cycles;

- to the regenerator - in the ORC cycle.

After triggering in the cycles of turbocharging, gas turbines, internal combustion engines, the combustion products are discharged into the atmosphere. It is characteristic that due to the possibility of using a higher degree of expansion of the working fluid, the efficiency of the considered power cycles increases. Typically, for example, in reciprocating internal combustion engines, the compression ratios for the expansion and compression processes are the same, so the exhaust energy does not work out completely.

In the ORC cycle, FIG. 6, the working fluid circulates through the elements 18-25, combined by pipelines 20 into a closed loop. The energy in this cycle of the external combustion engine is supplied from the heat source 21. Then, the hot working fluid, the organic heat carrier, performs work in the expansion stage 19, gives off heat in the regenerator 22 and discharges the unused heat through the cold heat exchanger 25 into the environment. Next, the working fluid circulates through pipelines 20 between the elements and repeats the cycle. It is compressed in the compression stage 18, is heated in the regenerator 22 by the heat of exhaust and in the regenerator 23 by the heat of intermediate selection coming from the expansion stage 19 from the selection pipe 24, then it is heated from the heat source 21, and the cycle repeats.

Claims (10)

1. A rotor-screw machine having an axisymmetric rotor with screw multi-start working channels, at least one, which are cut on the rotor in a ring, are connected from different ends to the nozzles of high and low pressure and are tightly closed by a housing and movable dividing dampers, characterized in that that the dividing flaps are fixed on the links of closed flexible chains of at least one channel moving crosswise in the grooves located in the housing, and the working channels are cut into any or all external morning and end surfaces of the rotor and are combined or individual stages of expansion and contraction. 2. The rotor-screw machine according to claim 1, characterized in that the grooves of the arrangement are orthogonal with respect to the channels. 3. The rotor-screw machine according to claim 1, characterized in that the cross section of the working channels is made expanding as they move away from the high-pressure pipe due to their gradual deepening by installing chains with an inclination to the surface of the rotor, and the shutters are made as a continuation of the chain links . 4. The rotor-screw machine according to claim 1, characterized in that the cross section of the working channels is made expanding as they move away from the high-pressure pipe, moreover, seals are installed on the dampers, made of movable elements fixed to the chain links, expandable and pressed by springs to the walls of the channels. 5. The rotor-screw machine according to claim 1 or 4, characterized in that the shutters are equipped with seals made of elastic, heat-resistant sheets with antifriction, wear-resistant coatings having the ability to expand and contract. 6. The rotor-screw machine according to claim 1, characterized in that it has an expansion stage and a compression stage mounted on a common shaft, moreover, they have the same type of rings with channels and are located on the rotor opposite to the center, with the zone being placed in the center of the rotor high pressure or vacuum. 7. The rotor-screw machine according to claim 1 or 6, characterized in that the expansion stage is connected to the exhaust of the main internal combustion engine, and the compression stage is connected to its air supply path. 8. The rotor-screw machine according to claim 1 or 6, characterized in that the compression stage is connected to the expansion stage through the combustion chamber. 9. The rotor-screw machine according to claim 1 or 6, characterized in that the compression stage is connected by inlet pipes to the expansion stage, and candles and / or fuel nozzles are installed in the expansion stage behind the supply pipes in high pressure zones. 10. The rotor-screw machine according to claim 1 or 6, characterized in that the compression and expansion stages are included by nozzles in the circulation circuit of the working fluid: compression stage, regenerators, hot heat exchanger, expansion stage with working fluid extraction pipes, regenerator and cold heat exchanger.

Images