DE102016010168A1 - Device and method as a CO2 drive turbine by using the thermal energy of a heat pump - Google Patents

Abstract

This technology, which is based on the enthalpy differences of a heat pump, should be used to reduce the overall fuel consumption and emissions of pollutants by conventional aircraft engines. To drive this device, a smaller amount of energy is needed compared to conventional turbines. By means of a heat pump pressure and temperature differences are generated, which allow to increase the pressure of CO2 so far that a connected turbine can be economically driven. The device is used as an aircraft engine.

Description

INTRODUCTION

Process as a thermal turbine for the propulsion of aircraft using the enthalpy differences of a heat pump, with which a high-pressure gas (such as R744, R744A, etc.) warms at a constant density and is liquefied after its expansion. It can u. U. also 2- or multi-stage heat pumps can be used.

NAME OF THE INVENTION

Device and method as a CO2 drive turbine by using the thermal energy of a heat pump.

TECHNICAL AREA

• Turbines, drive technology

STATE OF THE ART

It is not known if heat pumps are used to generate pressure differences in the propulsion turbines of an aircraft.

THE ROUNDING PROBLEM

Aircraft engine pollutant emissions are expected to be reduced as a result of climate change and pollution, given the current requirements and targets of national and international authorities. This can be achieved by using alternative techniques that reduce the fuel consumption of conventional engines.

GENERAL

This method uses the property of a liquid high-pressure gas (such as CO2) with low temperature increase and constant density to achieve high pressure differences.

According to the physical laws of energy conservation, these are predominantly artificially produced temperature and pressure differences. It uses both the energy supply by the evaporation of a refrigerant, as well as the energy dissipation by the liquefaction of a refrigerant in a physically closed system of a Carnot cycle process (cooling process) as an energy source.

All valves described below can be executed directly or pilot-controlled. All pressure control valves can be controlled mechanically, thermo-mechanically, or via pressure or temperature transmitters and electronics. The drives of all automated valves can be either mechanical, electro-mechanical, electrical, electro-magnetic, pneumatic, hydraulic, or equivalent. The listed heat exchangers can be designed as tube bundle, as well as plate, or micro-channel heat exchangers or other technologies.

The apparatus described below and the method described, which is used as an engine of aircraft, generated by the condensation energy of a heat pump high pressures of> 900 bar, which act on the high-pressure turbine of an engine. The high-pressure turbine (A2) and the low-pressure turbines (A3 & A4) are connected via a gearbox (A15) to the fan (A14) of the engine.

TECHNICAL DESCRIPTION

Fig. 1:

Representation of the aircraft engine (A1) with fan (A14), transmission (A15), high-pressure turbine (A2), low-pressure turbines (A3 & A4) and sheath flow (A16). The engine (A1) is filled with a high-pressure gas such. B. CO2 operated by the valve (A5) opens and a defined volume of CO2 under a high pressure in the high-pressure turbine (A2) is passed. The CO2 expands over several turbines (3 turbines are shown here, but this number can vary upwards or downwards). The power is transmitted via a gearbox (A15) and to the fan (A14).

Fig. 2:

Representation of the cycle processes in the log p-h diagram to illustrate the mode of operation. It should be noted that the drawing is intended only to understand the function.

The single-stage heat pump cycle with compressor (C1) can alternatively be carried out in two or three stages. Different refrigerants can be used. The evaporator cools the expanded high pressure gas [such as. B. R744, R744A, R503, etc.) hereinafter referred to as CO2] from point [4] to point [1] and liquefies it in the subcritical range (below the critical point). The liquefied CO2 is collected in a cooled collector (eg at -30 ° C) (point [1]) and then transferred via the heat exchanger (C20 or C21) to z. B. heated 80 ° C (point [2]), resulting in a pressure increase of about 21 bar to about 900 bar. The hot exhaust of the fuel-driven compressor drive motor (C1b) is supplied via the temperature-controlled 3-way Control valve (C28) into the heat exchanger (C23) to remove the CO2 from point [2] to point [3] ( 3 ) to heat.

All values are estimated and are intended only to understand the process and the concept. The pressures can be limited accordingly.

The liquid CO2, which is under high pressure in the transcritical range, is directed via the pressure-controlled injection valve (A5) first into the high-pressure turbine (A2) and then into the low-pressure turbines (A3, A4). The pressure is hereby z. B. 900 bar on z. B. 21 bar reduced (from point [3] to point [4]). The CO2 is discharged from the turbine, at z. B. 21 bar (-18 ° C) liquefied and in the collector, the z. B. is pre-cooled to -30 ° C, accumulated. For cooling the collector, as well as for the liquefaction of CO2 u. U. additionally or alternatively, the cold outside air from -30 ° C to -45 ° C at an altitude of z. B. 10 km can be used by appropriate heat exchangers are used.

The compression temperatures at the outlet of the compressor (C1) and / or the liquefaction energy of the heat pump cycle are used for the heating of the liquid CO2 in the collector (A6 or B6). The residual energy can be used for additional or alternative heating of the aircraft cabin.

3:

Extract from a CO2 log ph diagram (pressure enthalpy) with the isochore of about 1,000 kg / m ³ . When liquid CO2 is heated from approx. -18 ° C to approx. 80 ° C, the pressure in the closed container increases from approx. 21 bar to approx. 900 bar. Other isochores and temperatures can also be used so that the specific pressures can be adjusted to conventional engines.

4:

Schematic representation of the clockwise CO2 cycle (clockwise). The collector (A6) is from the heat pump (alternatively also from the outside air) on z. B. -30 ° C cooled. The solenoid valve (A11) is open, so that the liquefied CO2 from the condenser (C2) can be accumulated. The filled with liquid CO2 collector (B6) is from the heat pump to z. B. heated 80 ° C. The solenoid valve (B7) is open and with also open solenoid valve (C26) are z. B. 900 bar on the pressure regulator (C27).

The liquid level controller monitors the maximum CO2 level in the tank (C24), which is regulated so that the CO2 can expand when the temperature rises. If the maximum desired fluid level is exceeded, the solenoid valve (C26) is closed. The inlet pressure regulator (C27) prevents the pressure in the collector (A6 or B6) from falling below the set value of, for B. 900 bar falls when the solenoid valve (C26) is opened. The high-pressure CO2 in the tank (C24) is reheated to higher temperatures with the aid of the exhaust gas from the compressor drive motor (C1b) to reduce the density of CO2 in the transcritical range. If the injection valve (A5) opens at a predefined pressure, the engine (A1) is driven accordingly.

The float switch (B9) or other level control device monitors the CO2 level at the collector (B6). If this value is undershot, the system switches over to the adjacent collector (A6) filled with liquid CO2. For this purpose, the solenoid valves (B7 & A11) are closed and the solenoid valves (A7 & B11) are opened. The heat pump now cools the collector (B6) to z. B. -30 ° C down and heats the collector (A6) on z. + 80 ° C.

This change process is repeated according to the fill levels in the collectors (A6 & B6). The check valves (A8, B8, A10, B10, A15, B15 etc.) support the flow direction of the process.

Fig. 5:

Schematic representation of the left-hand heat pump cycle (counterclockwise).

The compressor (C1) is driven by an internal combustion engine (C1b), or equivalent. The hot exhaust gas from the drive motor (C1b) is used via the 3-way valve (C28) to reheat the CO2 in the tank (C24).

The compressor (C1) sucks the refrigerant at z. B. -30 ° C from the optional liquid separator (C2) and compresses it in the heat exchanger (C8). If the set condensing setpoint pressure is exceeded, the pressure regulator (C6) opens the inlet to the heat exchanger (C7), which can be operated air- or water-cooled, or can be connected to another heat recovery system, etc. B. to heat the aircraft cabin.

The liquefied refrigerant is stored in the optional collector (C9) and then fed to the evaporator (C3), where it is vaporized by the expansion valve (C16). If one of the CO2 collectors (A6 or B6) is to be heated, the corresponding solenoid valve (C17 or C22) opens the inlet of hot refrigerant into the heat exchanger (C20 or C21). Accordingly, the solenoid valve (C5) is closed.

If one of the CO2 collectors (A6 or B6) is to be cooled down, the corresponding solenoid valve (C14 or C15) opens the liquid refrigerant feed into the heat exchanger (C18 or C19), where it is removed from the expansion valve (C12 or C13 ) is evaporated. The check valves (including C10 & C11) support the flow direction of the process. The oil separator (C4) is optional.

Fig. 6:

Schematic representation of the common interconnection of both 3 and 4 , including the engine 1 ,

REACHED ADVANTAGES:

Saving fuel and reducing the overall weight of the aircraft, reducing the noise level, low outside temperatures at high altitudes can be used for cooling and possibly for the liquefaction of CO2, which is not consumed, but recycled in a closed cycle. Significant increase in engine performance through the use of high CO 2 pressure differences at the turbines.

Claims (10)

Method as a thermal engine for propulsion of aircraft, characterized in that a heat pump is used, the liquid high-pressure refrigerant heated at a constant volume to drive by the gained pressure increase a turbine whose power is transmitted to an aircraft engine. A method according to claim 1, characterized in that a heat pump directly or indirectly drives a drive shaft, or a turbine engine. A method according to claim 1 or claim 2, characterized in that the heat of condensation of a heat pump is used to heat the high pressure gas of another closed system to its transkritischem range and the evaporation energy of a heat pump is used to the high-pressure gas of another closed system in subcritical Liquefy area. Method according to one of claims 1 to 3, characterized in that the pressure differences of a high-pressure gas are used to enable the turbine of an aircraft engine in rotation. Method according to one of claims 1 to 4, characterized in that a heat pump is used to drive an aircraft. Method according to one of claims 1 to 5, characterized in that a heat pump two parallel cased container, which are each filled with a liquefied gas or filled, heat and / or can cool down. Method according to one of claims 1 to 6, characterized in that a turbine is operated with a recycled high-pressure gas by acting at the inlet of the turbine, the pressures in the trans-critical region of the high-pressure gas and at the outlet of the turbine, the pressures of the high-pressure gas in the subcritical region. Method according to one of claims 1 to 7, characterized in that a gas for driving an aircraft engine is used, which is not consumed, but is circulated continuously in a closed system. Method according to one of claims 1 to 8, characterized in that an engine, which is located in an aircraft, drives the compressor of a heat pump and the evaporation and liquefaction energy of the heat pump is used to drive the engines of the same aircraft. Method according to one of claims 1 to 9, characterized in that an already liquefied refrigerant is brought with the same further pressure and temperature increase in the trans-critical region of the same, then to relax it and thereby to drive a turbine.

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