POWER PLANT AND METHOD FOR OPERATING A POWER PLANT

Abstract

Method for operating a power plant for generating energy, comprising at least one stationary internal combustion engine (1) and a district heating system (20) connected to the at least one internal combustion engine (1) in a heat exchange relationship, wherein the at least one internal combustion engine (1) is configured to deliver a mechanical power by burning a fuel, wherein on the one hand the at least one internal combustion engine (1) is cooled and on the other hand heat is supplied to the district heating system (20) through a heat exchange between the district heating system (20) and the at least one internal combustion engine (1) and wherein at least one additional cooling device (12) is provided,
wherein the cooling of the at least one internal combustion engine (1) is effected—at least partially—using the at least one additional cooling device (12) when a transient performance requirement for the at least one internal combustion engine (1) occurs.

Claims

1. A method for operating a power plant for generating energy, comprising: at least one stationary internal combustion engine and a district heating system connected to the at least one internal combustion engine in a heat exchange relationship, wherein the at least one internal combustion engine is configured to deliver a mechanical power by burning a fuel, wherein on the one hand the at least one internal combustion engine is cooled and on the other hand heat is supplied to the district heating system through a heat exchange between the district heating system and the at least one internal combustion engine and at least one additional cooler, wherein the cooling of the at least one internal combustion engine is effected—at least partially—using the at least one additional cooler when a transient performance requirement for the at least one internal combustion engine occurs.

2. The method as set forth in claim 1, wherein the transient performance requirement relates to a start of the at least one internal combustion engine.

3. The method as set forth in claim 1, wherein a connection between the at least one additional cooler and a cooling system for the combustion air and/or the fuel of the at least one internal combustion engine is established when a transient performance requirement for the internal combustion engine occurs, wherein the cooling system comprises an intercooler.

4. The method as set forth in claim 1, wherein a connection between the at least one additional cooler and an engine cooling system is established when a transient performance requirement occurs.

5. The method as set forth in claim 1, wherein the at least one internal combustion engine is separated from the district heating system when a transient performance requirement occurs.

6. The method as set forth in claim 1, wherein the at least one additional cooler is provided for a plurality of internal combustion engines.

7. The method as set forth in claim 1, comprising an electric generator driven by the at least one internal combustion engine.

8. The method as set forth in claim 1, wherein the transient performance requirement relates to a performance increase of the at least one internal combustion engine, wherein the performance increase comprises an increase of power output and/or a decrease of emissions of the internal combustion engine.

9. The method as set forth in claim 1, wherein the—at least partial—cooling of the at least one internal combustion engine using the additional cooler is stopped after a transient performance requirement when a quasi-stationary performance requirement occurs.

10. The method as set forth in claim 1, wherein the additional cooler is provided for a safe operation of the at least one internal combustion engine.

11. A power plant for generating energy, comprising: at least one stationary internal combustion engine, wherein the at least one internal combustion engine is configured to deliver a mechanical power by burning a fuel, a district heating system connected to the at least one internal combustion engine, wherein through a heat exchange between the district heating system and the at least one internal combustion engine on the one hand the at least one internal combustion engine is cooled and on the other hand heat is supplied to the district heating system, at least one additional cooler and at least one open or closed loop control unit, wherein the at least one open or closed loop control unit is configured to open or closed loop control a cooling of the at least one internal combustion engine by activating and/or deactivating of the additional cooler when a transient performance requirement for the at least one internal combustion engine occurs.

12. The power plant for generating energy as set forth in claim 11, wherein the at least one additional cooler is configured as thermal reservoir comprising at least one roof top cooler and/or thermal storage mass.

13. The power plant for use of energy generation as set forth in claim 11, wherein the least one open or closed loop control unit is configured as a central engine control unit of the at least one internal combustion engine.

14. The power plant for use of energy generation as set forth in claim 11, wherein the at least one additional cooler comprises at least one circulation pump.

Description

[0035] Further details and advantages of the invention are apparent from the accompanying figures and the following description of the drawings. The figures show:

[0036] FIG. 1 a stationary internal combustion engine,

[0037] FIG. 2a an internal combustion engine in conjunction with district heating system and

[0038] FIG. 2b an internal combustion engine in conjunction with district heating system when a transient performance requirement occurs.

[0039] FIG. 1 shows a stationary international combustion engine 1, wherein the internal combustion engine 1 comprises a turbo charger 4. By means of the turbo charger 4 air or an air-fuel mixture can be charged for the combustion in the internal combustion engine 1. This air or air-fuel mixture is charged by the compressor 7 of the turbo charger 4. The turbo charger 4 further comprises an exhaust gas turbine 26, which is connected to the compressor 7 by a shaft 23. The exhaust gas turbine 26 is driven by exhaust gas coming from the internal combustion engine 1, where the exhaust gas is produced by combustion of the air fuel mixture.

[0040] This combustion normally takes place in the combustion chambers 2 of the internal combustion engine 1. For combustion in mixed charged internal combustion engines a charged air-fuel mixture is fed to the combustion chamber 2 of the internal combustion engine 1. For combustion in supercharged internal combustion engines having a fuel port injection a charged air is fed to the internal combustion engine 1, a fuel is separately fed to the internal combustion engine 1 by means of port injection nozzles. When charging air or an air-fuel mixture the air or the air-fuel mixture also is heated by the compression operation. For reducing the temperature of the air or the air-fuel mixture an intercooler 5 is provided. After passing the intercooler 5 the air or the air-fuel is guided to the combustion chambers 2 via the intake manifold 3.

[0041] The exhaust gas turbine 26 can be bypassed by means of a bypass conduct and a bypass valve 6. This bypass valve 4 can be connected with a control unit of the internal combustion engine 1, which is configured to open or closed loop control the bypass valve 6. The control unit of the internal combustion engine 1 can be configured to determine a pressure difference, from pressure measurements downstream and upstream of the exhaust gas turbine 26 and control the charge pressure by control an opening degree of the bypass valve 6.

[0042] Furthermore, the internal combustion engine 1 comprises an engine cooling system 8 for cooling the internal combustion engine 1 during operation. In this embodiment of an internal combustion engine 1 the cooling system 8 comprises a supply line 9 (corning from the district heating system 20—explained in the following figures in more detail) entering the internal combustion engine 1 and passing through the intercooler 5 cooling the air or the air-fuel. Here the intercooler 5 acts as a heat exchanger. After passing the intercooler the tempering medium of the cooling system 8 is guided to the engine block 27, for cooling the engine block 27. Before entering the return line 10—in the shown embodiment of FIG. 1—a heat exchange takes place between the medium of the cooling system 8 and the exhaust gas in the exhaust heat exchanger 19 for heating the tempering medium as much as possible in order to increase the efficiency of the district heating system 20.

[0043] FIG. 2a shows the internal combustion engine 1 (embodiment for example as in FIG. 1) in conjunction with a district heating system 20 during normal operation. A tempering medium is pumped by the circulation pump 14 corning from a supply line 21 of the district heating system 20 to the internal combustion engine 1, wherein through a heat exchange between the district heating system 20 and the at least one internal combustion engine 1 on the one hand the at least one internal combustion engine 1 is cooled and on the other hand heat is supplied to the district heating system 20. After passing through the internal combustion engine 1 the tempering medium is led through the return line 22 of the district heating system 20 to a field of application (not shown by the figures), where the thermal energy from the district heating system 20 is used for heating or is used for another thermal process.

[0044] An emergency cooling device (used as additional cooling device 12 in this embodiment) is provided for cooling the internal combustion engine 1 if the cooling of the internal combustion engine 1 can no longer be performed by the district heating system 20 (e.g. because of a failure of the district heating system). This emergency cooling device ensures a safe operation of the internal combustion engine 1.

[0045] The additional cooling circuit comprises a plurality of cooling devices (in this embodiment designed as roof top coolers 11). Using another circulation pump 13 the tempering medium in the additional cooling circuit is circulated. The circulation pump 13 can be controlled by an open or closed loop control unit 24. The open or closed loop control unit 24 is connected to the circulation pump 13 via signal lines 25 (shown in the figure as dashed lines).

[0046] The open or closed loop control unit 24 is also connected to several valves 16, 17, 18 to control the medium flow of the district heating system 20.

[0047] During normal operation—quasi-stationary performance requirement—(as shown by FIG. 2a) the medium flow is controlled by the open or closed loop control unit 24 by closed valves 16, 18 and open valve 17. This allows the tempering medium to flow directly from the supply line 21 of the district heating system 20 to the internal combustions engine 1 and after a heat exchange with the internal combustion engine 1 from the internal combustions engine 1 to the return line 22 of the district heating system 20.

[0048] The open or closed loop control unit 24 is configured to close valve 17 and open valve 18 when a transient performance requirement occurs for the at least one internal combustion engine 1 (as shown in FIG. 2b), wherein the district heating system 20 is separated from the cooling system 8 of the internal combustion engine 1. At the same time the open or closed loop control unit 24 is configured to open valve 16 and activate the circulation pump 13 (if this pump does not already work). By opening the valve 16 the engine cooling system 8 is connected to the additional cooling device 12, wherein the internal combustion engine 1 is cooled by the additional cooling device 12 via the heat exchanger 15.

[0049] It can be provided that after the occurrence of a transient performance requirement to the internal combustion engine 1 the open or closed loop control unit 24 closes the valves 16, 18 and opens the valve 17 to continue with normal operation (as explained in connection with FIG. 2a).

[0050] It can be provided that the at least one additional cooling circuit 12 comprises at least one (thermal) reservoir 11′ (also referred to roof top coolers), wherein an exchange of heat between the cooling medium coming from the internal combustion engine, preferably coming from intake manifold of the internal combustion engine, and said reservoir takes place during a transient performance requirement. The (thermal) reservoir can be any fluid like air or liquid.

REFERENCE SIGNS

[0051] 1 internal combustion engine [0052] 2 combustion chamber [0053] 3 intake manifold [0054] 4 turbo charger [0055] 5 intercooler [0056] 6 bypass valve [0057] 7 compressor [0058] 8 engine cooling system [0059] 9 supply line of the engine cooling circuit [0060] 10 return line of the engine cooling circuit [0061] 11 roof top cooler [0062] 11′ (thermal) reservoir [0063] 12 additional cooling device [0064] 13 circulation pump [0065] 14 circulation pump [0066] 15 heat exchanger 15 [0067] 16 valve [0068] 17 valve [0069] 18 valve [0070] 19 exhaust heat exchanger [0071] 20 district heating system [0072] 21 supply line of the district heating system [0073] 22 return line of the district heating system [0074] 23 shaft [0075] 24 open or closed loop control unit [0076] 25 signal lines [0077] 26 exhaust gas turbine [0078] 27 engine block