GB2587858A

GB2587858A - Arrangement for energy provision

Info

Publication number: GB2587858A
Application number: GB2009449.6A
Authority: GB
Inventors: Schlegl Gerhard; Lange Jens
Original assignee: MAN Energy Solutions SE
Current assignee: Everllence SE
Priority date: 2019-08-01
Filing date: 2020-06-22
Publication date: 2021-04-14
Anticipated expiration: 2040-06-22
Also published as: FI20205776A1; FI129529B; DE102019120817A1; GB2587858B; GB202009449D0

Abstract

An arrangement for energy provision 1, which comprises at least one internal combustion engine 2 for energy provision, a power turbine 3 using part of an exhaust gas mass flow of the engine 2, a planetary gear 6 on a shaft 7 of the power turbine and a generator 5, which is connected to the planetary gear 6 for generating electric energy. Wherein on an exhaust line 10 of the internal combustion engine 2, a high-pressure turbine 8, a high-pressure compressor 9, a low-pressure turbine 11 with a variable turbine geometry and a low-pressure compressor 12 are flow-effectively arranged in series for realising an exhaust gas mass flow control. The exhaust gas mass flow control is via the variable turbine geometry of the low-pressure turbine 11, and upstream of the high-pressure turbine 8 a controllable tap 13 is arranged on the exhaust line 10, which conducts part of the exhaust gas mass flow of the engine 2 between the engine and the power turbine 3. Furthermore, the invention relates to a method for operating the arrangement.

Description

ARRANGEMENT FOR ENERGY PROVISION

Field

An embodiment of the invention relates to an arrangement for energy provision, which comprises at least one internal combustion engine for energy provision, a power turbine for utilising a part of an exhaust gas mass flow of the internal combustion engine, a planetary gear arranged on a shaft of the power turbine and a generator, which for generating electric energy is drive-effectively connected to the planetary gear. Another embodiment of the invention relates to a method for the operation of this arrangement.

Background

Power plants for energy generation are generally operated by means of an internal combustion engine, preferentially a diesel or gas engine as drive unit for the electric generator. Power plants, in particular power plants for being able to offset peak loads, which are largely embodied as pumped-storage power plants, compressed air storage power plants or gas turbine power plants, reach rates of change of up to 20% of the rated power per minute and have a run-up time of only a few minutes. The power can be controlled between 20 and 100'). They are utilised in order to match the fluctuations in the power demand or the generator input, which cannot be compensated by the other power plant types, or with which this is not economically practical. Peak load power plants are mostly employed only a few hours per day: at the consumption peaks, in the case of major load increases in the grid and in the case of unplanned fluctuations of power consumption and generation. Through the consumption of natural gas or -2 -pump energy, the power generated by these is significantly more expensive than the power of other power plant types.

Summary

Embodiments of the invention provide an arrangement for providing energy in particular of a power plant and a method for operating such an arrangement, which increases the efficiency and consequently lowers the costs for the energy provision.

According to an embodiment of the invention, an arrangement for energy provision is proposed, which comprises at least one internal combustion engine for energy provision, a power turbine for utilising a part of an exhaust gas mass flow of the internal combustion engine, a planetary gear arranged on a shaft of the power turbine and a generator, which is drive-effectively connected to the planetary gear for generating electric energy. On an exhaust line of the internal combustion engine, a high-pressure turbine, a high-pressure compressor, a low-pressure turbine with a variable turbine geometry and a low-pressure compressor are flow-effectively arranged in series for realising an exhaust gas mass flow control. The exhaust gas mass flow control is effected at least by means of the variable turbine geometry of the low-pressure turbine and upstream of the high-pressure turbine a controllable tap is arranged on the exhaust line, which is formed for conducting a part of the exhaust gas mass flow of the internal combustion engine between the same and the power turbine. The turbo compounding, during which an internal combustion engine, in which the energy content of the exhaust gases is utilised through a power turbine connected downstream, combined with an exhaust gas mass flow control by means of the variable turbine geometry on the low-pressure turbine of the -3 -supercharging group, results in a power increase and an efficiency increase of the multi-stage supercharged internal combustion engines. Furthermore, an improvement of the response behaviour of the supercharging group in the engine part load and resulting from this a better part load consumpcion of the internal combustion engine materialises. Apart from this, the load switching behaviour is improved. The tapping of the exhaust gas mass flow that is additionally available from the minimum power of the internal combustion engine is preferably effected via the former waste gate connection in the exhaust line of the internal combustion engine upstream of the high-pressure turbine.

In one embodiment, the tap comprises a controllable shut-off device, by means of which the exhaust gas mass flow from the internal combustion engine to the power turbine is controllable. In the case of loads of the internal combustion engine that are lower than a predetermined minimum power, the tap is closed by means of a shut-off device. In this way, the internal combustion engine can realise quicker load ramps in this operating range by means of the variable turbine geometry.

In one embodiment, the arrangement for the energy provision is designed so that the internal combustion engine and the power turbine are each supercharged in a single stage or in multiple stages. Here it is favourable that the arrangement can be adapted to the respective peripheral conditions.

In one embodiment, a second internal combustion engine is flow-effectively connected to the power turbine or energy provision. The power control range resulting from the use of the planetary gear of approximately 50% -4 -of the rated power of the power turbine makes it possible to connect two engines to one power turbine. By way of this, the efficiency of the arrangement is further optimised. In this, the embodiment makes possible the combination of an engine and a power turbine as well as two engines and a power turbine.

Furthermore, in one embodiment, on the respective high-pressure compressor and on the respective low-pressure compressor two charge air coolers for recirculating and cooling a part of the exhaust gas mass flow to the internal combustion engine each are arranged. For realising maximum compressor efficiencies and thus also a maximum overall efficiency of the arrangement, the charge air coolers are operated with maximum cooling.

In one embodiment, the tap is connected to the exhaust line downstream of the low-pressure compressor. By way of this, the exhaust gas can be conducted from the power turbine back into the exhaust line and the further plant components, such as for example exhaust gas after-treatment systems, can likewise be utilised for this exhaust gas conducted through the power turbine.

According to another embodiment of the invention, a method for operating an arrangement for energy provision according to the above features is proposed, comprising the following steps: a. generating an excess of the exhaust gas mass flow through the high-pressure compressor, the low-pressure compressor, and a charge air cooler from a predetermined power of the internal combustion engine; b. opening the controllable shut-off device of the tap; c. extracting at least a part of the additionally generated exhaust gas mass flow via the tap; and d. expanding the extracted exhaust gas mass flow in the power turbine. -5 -

The configuration of the supercharging group and of the charge air cooling is effected in such a manner that from a minimum power to be determined an exhaust gas mass flow excess is generated. The engine start and the synchronisation of the engines is effected separately for each engine. A run-up of the engines from Or load up to the predetermined power of the internal combustion engine likewise takes place separately for each engine with closed shut-off device of the tap. For connecting the power turbine, the shut-off device is slowly opened from the reaching of the predetermined power. As soon as the power turbine is in engagement, the two connected engines have to supply comparable exhaust gas parameters in order to largely exclude a mutual influencing of the engines. For this reason, both internal combustion engines are operated with the same load.

In one embodiment, the exhaust gas mass flow control in step a) is effected by means of the variable turbine geometry of the low-pressure turbine.

In one embodiment, the predetermined power of the combustion engine in step a) amounts to 85% to 90%.

In one embodiment, in step a) the charge air coolers are operated with at least 95% of their possible cooling capacity. By way of this, a maximum compressor efficiency and consequently also a maximum overall efficiency of the method is made possible. Here, a guarantee temperature is 10° C. In one embodiment, a scavenging pressure gradient is reduced by means of the variable turbine geometry of the low-pressure turbine. The reduction of the scavenging pressure gradient, for example from 1.4 bar -6 -to 1 bar, makes available additional exhaust gas pressure potential for the power turbine and thus increases the overall efficiency of the method.

In one embodiment, in step d) the power of the power turbine is controlled by means of the planetary gear and a bypass. Preferentially, the method is carried out so that during a quick load change of the internal combustion engine or a failure of the power turbine the bypass is opened. During dynamic operating requirements, such as for example rapid engine load changes, and during a failure of the power turbine, the power turbine can be bypassed by means of a rapid bypass control.

In one embodiment, a recirculation of the extracted exhaust gas mass flow into the exhaust line via the tap takes place downstream of the low-pressure compressor.

Brief Description of the Drawing

These and other embodiments of the invention are presented in more detail by way of the figure together with the description. The figure shows: Fig. 1 a schematic diagram of an arrangement for energy provision.

Detailed Description

In Figure 1, a schematic diagram of an arrangement for energy provision 1 with two internal combustion engines 2 is shown. On each of the two internal combustion engines 2, an exhaust line 10 is formed which conducts the exhaust gas of the internal combustion engine 2 through a high-pressure turbine 6, a high-pressure compressor 9, a low-pressure turbine 11 with a variable turbine geometry and a low-pressure compressor 12. These four components arranged on the respective exhaust line 10, which are also referred to as supercharging group, are flow-effectively arranged in series for realising an exhaust gas mass flow control. Here, at least the variable turbine geometry of the low-pressure turbine 11 is provided for the exhaust gas mass flow control.

Furthermore, two charge air coolers 15 each for cooling and for recirculating a part of the exhaust gas mass flow to the respective internal combustion engine 2 are arranged on the two high-pressure compressors 9 and on the two low-pressure compressors 12.

Figure 1 shows, furthermore, that on the two internal combustion engines 2, in each case upstream of the high-pressure turbine 8, a controllable tap 13 is arranged on the exhaust line 10. This tap 13 flow-effectively conducts a part of the exhaust gas mass flow of the internal combustion engine 2 from the same to a power turbine 3, which is arranged between the two internal combustion engines 2 for energy provision. The power turbine 3 serves for utilising the diverted part of the exhaust gas mass flow of the internal combustion engine 2 by means of a planetary gear 6 arranged on a shaft of the power turbine 3 and of a generator 5, which for generating electric energy is drive-effectively connected to the planet gear 6.

Furthermore, the tap 13 comprises a shut-off device 14, by means of which the exhaust gas mass flow from the internal combustion engine 2 to the power turbine 3 is controllable. On the power turbine 3, a bypass 16 is additionally formed, by way of which the exhaust gas mass flow can be conducted past the power turbine 3. Following the generator 5, the tap 13, is connected to the exhaust line 10 downstream of the outlet of the low-pressure compressor 12. This exemplary embodiment can be operated with the method described above in more detail.

List of reference numbers 1 Arrangement for energy provision 2 Internal combustion engine Power turbine Generator 6 Planetary gear 8 High-pressure turbine 9 High-pressure compressor Exhaust line 11 Low-pressure turbine 12 Low-pressure compressor 13 Tap 14 Shut-off device Charge air cooler 16 Bypass

Claims

PATENT CLAIMS1. An arrangement for energy provision (1), comprising: at least one internal combustion engine (2) for energy provision; a power turbine (3) for utilising a part of an exhaust gas mass flow of the internal combustion engine (2); a planetary gear (6) arranged on a shaft of the power turbine (3); and a generator (5), which is drive-effectively connected to the planetary gear (6) for generating electric energy, wherein on an exhaust line (10) of the internal combustion engine (2) a high-pressure turbine (6), a high-pressure compressor (9), a low-pressure turbine (11) with a variable turbine geometry, and a low-pressure compressor (12) are flow-effectively arranged in series for realising an exhaust gas mass flow control, wherein the exhaust gas mass flow con7rol is effected at least by means of the variable turbine geometry of the low-pressure turbine (11), and wherein upstream of the high-pressure turbine (8) a controllable tap (13) is arranged on the exhaust line (10), which is formed for conducting a part of the exhaust gas mass flow of the internal combustion engine (2) between the same and the power turbine (3).
2. The arrangement for energy provision (1) according to Claim 1, wherein the tap (13) comprises a controllable shut-off device (14), by means of which the exhaust gas mass flow from the internal combustion engine (2) to the power turbine (3) is controllable.
3. The arrangement for energy provision (1) according to Claim 1 or 2, wherein the internal combustion engine (2) and the power turbine (3) are each supercharged in a single stage or multiple stages.
4. The arrangement for energy provision (1) according to any one of the Claims 1 to 3, wherein a second internal combustion engine (2) for energy provision is flow-effectively connected to the power turbine (3).
5. The arrangement for energy provision (1) according to any one of the preceding claims, wherein on the respective high-pressure compressor (9) and on the respective low-pressure compressor (12) two charge air coolers (15) each are arranged for recirculating and cooling a part of the exhaust gas mass flow to the internal combustion engine (2).
6. The arrangement for energy provision (1) according to any one of the preceding claims, wherein the tap (13) is connected to the exhaust line (10) downstream of the low-pressure compressor (12).
7. A method for operating an arrangement for energy provision (1) according to any one of the preceding Claims 2 to 4, comprising the following steps: a. generating an excess of the exhaust gas mass flow through the high-pressure compressor (9), the low-pressure compressor (12), and a charge air cooler (15) from a predetermined power of the combustion engine (2); b. opening the controllable shut-off device (14) of the tap (13); c. extracting at least a part of the additionally generated exhaust gas mass flow via the tap (13); and d. expanding the extracted exhaust gas mass flow in the power turbine (3).
8. The method for operating an arrangement for energy provision (1) according to Claim 7, wherein the exhaust gas mass flow control in step a) takes place by means of the variable turbine geometry of the low-pressure turbine (11).
9. The method for operating an arrangement for energy provision (1) according to Claim 7 or 8, wherein the predetermined power of the internal combustion engine (2) in step a) amounts to 85% to 90%.
10. The method for operating an arrangement for energy provision (1) according to any one of the Claims 7 to 9, wherein in step a) the charge air coolers (15) are operated with at least 95% of their possible cooling capacity.
U. The method for operating an arrangement for energy provision (1) according to any one of the Claims 7 to 10, wherein by means of the variable turbine geometry the low-pressure turbine;11) a scavenging pressure gradient is reduced.
12. The method for operating an arrangement for energy provision (1) according to any one of the Claims 7 to 11, wherein in step d) the power of the power turbine (3) is controlled by means of the planetary gear (6) and a bypass (16).
13. The method for operating an arrangement for energy provision (1) according to any one of the Claims 7 to 12, wherein during a rapid load change of the internal combustion engine (2) or a failure of the power turbine (3), the bypass (16) is opened.
14. The method for operating an arrangement for energy provision (1) according to any one of the Claims 7 to 13, wherein a recirculation of the extracted exhaust gas mass flow into the exhaust line (10) via the tap (13) takes place downstream of the low-pressure compressor (12).