WO2013167636A1

WO2013167636A1 - Method and system for retrofitting an aircraft

Info

Publication number: WO2013167636A1
Application number: PCT/EP2013/059553
Authority: WO
Inventors: Fritz PAPMAHL; Julian TERPITZ; Chaojie Zhang
Original assignee: Tge Gas Engineering Gmbh
Priority date: 2012-05-08
Filing date: 2013-05-08
Publication date: 2013-11-14
Also published as: DE102012207574A1

Abstract

The invention relates to a method and system for retrofitting an aircraft in particular for driving a cryogenic fuel pump of aircraft engines. One of the problems of operating a drive of a cryogenic fuel pump is its high electric energy requirement and the reduced space on board an aircraft, which needs to be retrofitted in a simple manner. In order to solve the problem, the invention relates to a cryogenic fuel pump for an aircraft engine. Furthermore, a bleed air extraction point for the aircraft engine is provided and an electric and/or mechanical driving force for the cryogenic fuel pump is generated by means of the extracted bled air. Said cryogenic fuel pump and the device for generating an electric and/or mechanical driving force are provided in the fuselage of the aircraft.

Description

Method and system for retrofitting an aircraft

The invention relates to a method and a system for retrofitting an aircraft, in particular for driving a cryogenic fuel pump for an aircraft engine.

Aircraft engines regularly include a compressor, a

Combustion chamber and a turbine. Here, sucked air is first compressed in the compressor. In the downstream combustion chamber, a fuel is added to the compressed air and burned. The built-up energy is relaxed in the following turbine. The turbine is usually coupled to the compressor and thereby drives the upstream compressor. In the course of development for a switch to cryogenic fuels

In particular, liquefied natural gas (LNG) will be placed on the drive of cryogenic fuel pumps for aircraft engines increased demands. Cryogenic fuels such as liquefied natural gas (LNG) are usually stored at temperatures around -1 60 ° C (1 1 3K) and close to atmospheric pressure. Such fuels can therefore not be stored in conventional containers such as kerosene tanks in airplanes. In addition, cryogenic fuel pumps for aircraft engines must ensure a reliable supply of fuel to the aircraft engine, especially during different flight phases and environmental variables, which generally require different pressure and flow parameters.

Furthermore, cryogenic fuel pumps are preferably to be installed in addition to the existing fuel system to a simple

Retrofitting or converting an aircraft to allow. The usual fuel pumps for kerosene are usually driven by a gearbox directly from the aircraft engine.

It is known to take compressed air from an aircraft engine and use it to control and control the aircraft engine. The So-called bleed air can also be used for Einspelsung in aircraft systems such as heat regulation and pressure supply.

From the document US 201 0/00031 48 a system for driving a fuel pump for an engine is known, comprising an electric motor, a control unit and a compressed air turbine, which is controlled by means of a vertical valve. The compressed air turbine is made by bleed air from a

Compressor of the engine operated. The compressed air turbine can be operated to drive the fuel pump together with the electric motor.

Cryogenic fuels such as liquefied natural gas are strongly cooled and stored at low temperatures, for example, from -1 64 to -150 ° C. The particular requirements for the propulsion of cryogenic fuels resulting therefrom, and in particular the limited space on board aircraft complicate the safe installation, modification and reliable operation of cryogenic fuel pumps for aircraft engines.

Another problem is the high demand for electrical energy for the cryogenic fuel pumps, which can be more than 100 kW, especially when starting an aircraft, and the existing electrical power

Supply systems on board aircraft overwhelmed.

The invention has for its object to develop an improved method and system for retrofitting an aircraft, in particular for driving a cryogenic fuel pump for an aircraft engine, which ensures in particular a safe operation of the fuel pump.

The object is achieved by a method having the features of claim 1. Advantageous embodiments emerge from the dependent subclaims. To solve the problem, a system further comprises the features of the independent claim.

To solve the problem is a cryogenic fuel pump for a

Aircraft engine provided in an aircraft. Furthermore, a

Zapfluftantnahme provided for the aircraft engine and with the taken bleed air generates an electrical and / or mechanical driving force for the cryogenic fuel pump. The cryogenic fuel pump is provided in particular in the fuselage of an aircraft. The generation of an electric and / or mechanical driving force for the cryogenic fuel pump by means of the bleed air taken enables the driving force for the cryogenic fuel pump without a mechanical coupling between the aircraft engine and cryogenic

Fuel pump can be generated. Aircraft engine and cryogenic fuel pump therefore have no mechanical connection to

Transmission of a driving force, as is common, for example, in kerosene-operated fuel pumps of the prior art. On this catfish, the cryogenic fuel pump can be flexibly arranged on board an aircraft without consuming, constructive

Adjustments to the aircraft In particular, the aircraft engine are required. Consequently, an aircraft can easily be retrofitted or retrofitted with a drive for a cryogenic fuel pump. Due to the limited installation space on board aircraft, in particular on the aircraft engine, this can be realized structurally advantageously if the cryogenic fuel pump is provided in the fuselage of the aircraft. In addition, it is welter advantageous to also arrange the device for generating an electrical and / or mechanical energy from bleed air for the cryogenic fuel pump in the fuselage. The fuselage can basically contain the space for passengers and payload.

Vorzugswelse the cryogenic fuel pump is provided in the space of the payload to reduce the conversion effort welter. The provision of the cryogenic fuel pump in the fuselage also enables efficient thermal isolation and safety-related separation. In addition, if the device for generating electrical and / or mechanical energy from bleed air is also provided in the aircraft fuselage, one obtains a particularly compact system for driving a cryogenic Fuel pump that can be retrofitted in technically simple catfish in different aircraft.

The cryogenic fuel used is preferably liquefied natural gas (LNG), which is cooled to a temperature of -164 to -150 ° C. The

Flüssiglgerdags is basically supplied in vaporized form the aircraft engine in particular the combustion chamber. The Einspelsung In the

Combustion chamber is preferably at a pressure above the

Combustion chamber pressure.

The bleed air takes vorvollhafterwelse the compressor of the

Aircraft engine, so that compressed air is taken. The

Depending on the design of the aircraft engine, bleed air extraction can be provided on a sheath flow and / or core flow of the aircraft engine. The pressure of the compressed air generated in the engine as well as its temperature basically change depending on the operating or flight phase. The energy demand of the cryogenic fuel pump is developing

Essentially approximately parallel to it. In one embodiment, it is provided to generate an electric drive force for the cryogenic fuel pump with an expander and a generator coupled thereto. The expander uses the energy of the extracted bleed air from the aircraft engine to drive the generator.

Cryogenic fuel pumps with low energy requirements can be fed from the existing supply network of an aircraft, for example, a generator coupled to the aircraft engine.

Alternatively or additionally, an additional auxiliary power unit (APU) to supply the cryogenic fuel pump can be provided.

Preferably, the cryogenic fuel such as liquefied natural gas is supplied under high pressure to a combustion chamber of the aircraft. The pressure of a

supplied cryogenic fuel is preferably increased above the combustion chamber pressure. At takeoffs of an aircraft may be The energy demand of the cryogenic fuel pump also increase. The bleed air extraction and the device for generating an electrical and / or mechanical driving force are vortellhafterweise designed so that the maximum energy demand of the cryogenic fuel pump is covered. The existing supply network of an aircraft can thus

remain largely unchanged. The conversion of an aircraft can thereby be simplified and it can be ensured that both the cryogenic fuel pump and one beyond

existing parallel fuel pump can be reliably operated.

In a further embodiment is provided, a mechanical

Driving force for the cryogenic fuel pump Especially with a

Gas expansion engine or a compressed air turbine to produce. Of the

Gas expansion engine or the compressed air turbine uses the energy of the extracted bleed air to mechanically drive the coupled thereto cryogenic fuel pump. For improved control and / or control of the mechanical driving force of the cryogenic fuel pump can

Control valve can be provided. In a further preferred embodiment, a heat exchanger is provided in particular evaporator, which is able to transfer the thermal energy of the withdrawn bleed air to a cryogenic fuel. The heat exchanger is preferably designed so that the cryogenic

Fuel is evaporated while doing so. Vorteilhafterwelse is the

Heat exchanger In particular evaporator downstream of the device for generating an electrical and / or mechanical driving force for the fuel pump by means of the drawn bleed air. The evaporated

Cryogenic fuel such as vaporized LNG may then be supplied to a combustor of the aircraft engine for combustion.

Vorzugswelse If at least one container for a cryogenic fuel such as liquefied natural gas is provided in the aircraft, with the cryogenic

Fuel pump is connected for supplying the fuel. The container for the cryogenic fuel is preferably arranged lim hull of the aircraft. The container may be connected to other containers for storing a cryogenic fuel, in particular such that a continuous supply of the cryogenic fuel from the downstream containers is possible. Alternatively or additionally, the container for a cryogenic fuel may comprise the cryogenic fuel pump inside the container, so that a separately provided connection for supplying the cryogenic fuel to the fuel pump is eliminated and the fuel pump can be supplied directly with the cryogenic fuel. As a result, problems with leakage or insulation can be avoided, so that overall a compact and energy-efficient arrangement is created. It is also preferred to operate a cryogenic fuel pump, which is internally provided in a container, with electrical driving force.

Due to the special thermal requirements for storage of a cryogenic fuel can be transferred to this catfish the transmission of

Driving force to internally provided fuel pump simplified realize.

In cryogenic fuel pumps which are provided externally to a container for a cryogenic fuel, it is also possible, instead of an electric drive, a mechanical driving force for the

Provide fuel pump. This can be achieved via the compressed bleed air in the manner described above and catfish.

For a supply of the cryogenic fuel to the combustion chamber of

Aircraft engine is preferably provided a fuel supply from the cryogenic fuel pump to the combustion chamber, in such a way that the cryogenic fuel can be supplied in addition to another fuel such as kerosene. Thus, the cryogenic fuel system can be used independently of a kerosene-based fuel system. The parallel use of a cryogenic fuel pump and a

existing fuel pump In the plane allows a simple

Converting to cryogenic fuels, so that converted aircraft

for example, can be operated flexibly with kerosene and LNG. In the following, with reference to the drawings

Embodiments of the invention will be described and explained in greater detail for better understanding. 1 is a schematic representation of a system for driving a cryogenic fuel pump by means of electrical driving force and

Flg. 2 shows a schematic representation of a system for driving a cryogenic fuel pump by means of mechanical driving force. According to FIG. 1, an aircraft engine 1 comprises a compressor 2, a combustion chamber 3 and a turbine 4. A bleed air intake 5 is located at

Compressor 2 is provided to remove compressed air from the aircraft engine 1. The bleed air extraction is connected to an expander 6, which is preferably arranged in the fuselage of an aircraft.

The expander 6 is coupled to a generator 7 for generating an electric driving force. The generator 7 feeds a motor 1 3 to

Driving a cryogenic fuel pump 8. The cryogenic fuel pump 8 may be provided inside a container for a cryogenic fuel 9. This is particularly advantageous in connection with an electric drive of the fuel pump. 8

The cryogenic fuel in the container 9 is supplied from the fuel pump 8 by means of a fuel supply 10 to the aircraft engine 1, in particular a combustion chamber 3. The cryogenic fuel is preferably supplied in a vaporized form. For this purpose, a heat exchanger such. an evaporator 1 1 are provided in the fuel supply 1 0. The thermal energy for vaporizing the cryogenic fuel is in a preferred embodiment of the from the aircraft engine. 1

provided bleed air. It is particularly advantageous in Im

Connection to the generation of an electrical and / or mechanical driving force for the fuel pump 8 with the help of the bleed air taken to use this at the same time in the downstream evaporator 1 1, since the bleed air usually still has sufficient thermal energy. Moreover, it is also advantageous to arrange the system according to the invention essentially in the fuselage. The distinction between the space of the aircraft engine 1 and the space of the

Fuselage is illustrated by the dashed line. As can be seen from Figure l except for the line to bleed air 5 and the

Line for fuel supply 1 0 all other components preferably provided in the fuselage. Consequently, aircraft can be retrofitted in a technically simple catfish with the system according to the invention, without costly conversion measures are required or a

Re-approval of an aircraft must be obtained. In addition, the design and safety requirements for storing and delivering cryogenic fuels such as LNG can be implemented by such an arrangement improved. The available space of a

Aircraft fuselage in particular the space provided for payload can then In suitable catfish for the conversion of a

Aircraft are used. In addition, the cryogenic fuel system can also be used in parallel with an existing kerosene-based fuel system, allowing for flexible operation of an aircraft engine.

FIG. 2 shows a further embodiment in which a gas expansion motor or a compressed air turbine 1 2 is connected to the bleed air take-off 5 in order to provide a mechanical drive force. The so provided

Driving force is transmitted by coupling to the fuel pump 8. The fuel pump 8 may alternatively also outside of the container. 9

be arranged to reduce, for example, a heat input into the container 9.

Claims

claims

1 . Method for retrofitting an aircraft In particular for driving a cryogenic fuel pump for an aircraft engine, in which a cryogenic fuel pump (8) for an aircraft engine (1) in one

Aircraft is preferably provided in the fuselage of an aircraft, a bleed air sampling (5) is arranged on the aircraft engine, and with the drawn bleed air, an electrical and / or mechanical

Driving force for the fuel pump (8) is generated.

2. Method according to the preceding claim, characterized in that for the generation of an electrical driving force for the

Fuel pump an expander (6] and a generator coupled thereto (7) are provided.

3. The method according to any one of the preceding claims, characterized

characterized in that for generating a mechanical driving force for the fuel pump, a gas expansion engine or a

Compressed air turbine (1 2) is provided.

4. The method according to any one of the preceding claims, characterized

characterized in that a heat exchanger (1 1) In particular

Evaporator transfers the thermal energy of the withdrawn bleed air to a cryogenic fuel, preferably downstream of

Generation of an electrical and / or mechanical driving force for the fuel pump. , System for carrying out the method according to one of the preceding claims with a bleed air extraction (5) for or at one

Aircraft engine (1) for generating a driving force for a cryogenic fuel pump (8), characterized by a device (6, 7] for generating electrical energy from bleed air or a device for generating mechanical energy from bleed air, which with the Connected to bleed air extraction is that an electrical and / or mechanical driving force can be generated for the fuel pump. System according to the preceding claim, characterized. in that the cryogenic fuel pump (8) and / or the device for

Generation of electrical or mechanical energy from bleed air Located in the fuselage of an aircraft is / are.

System according to one of the preceding claims, characterized

in that the device for generating electrical energy from bleed air comprises an expander (6) and a generator (7) coupled thereto.

System according to one of the preceding claims, characterized

in that the device for generating mechanical energy from bleed air comprises a gas expansion motor or a compressed air turbine (1 2).

A system according to any one of the preceding claims, characterized by a cryogenic fuel container (9) connected to the fuel pump for supplying the fuel or comprising the fuel pump inside the container. System according to one of the preceding claims, characterized by a fuel supply (1 0) from the fuel pump to

An aircraft engine, in particular a combustion chamber (3), preferably in such a way that the cryogenic fuel can be supplied in addition to another fuel. System according to one of the preceding claims, characterized by a heat exchanger (1 1) for the fuel supply (1 0). which is able to transmit the thermal energy of the bleed air to a cryogenic fuel, which in particular downstream of the device for Generation of an electrical and / or mechanical driving force from bleed air is provided.