DE762514C - Internal combustion turbine system of high performance - Google Patents

Description

Combustion turbine system with high performance For every internal combustion turbine system there is a certain pressure ratio at which the system has the most favorable efficiency achieved. The level of this pressure ratio is influenced by many factors, so z. B. on the level of the turbine and compressor efficiency, on the gas inlet temperature, on the level of pressure loss, on the level of waste heat utilization, etc.

Furthermore, the pressure ratio is influenced by the type of work process, d. H. 'Whether the compression is adiabatic or isothermal and the expansion adiabatic or isothermal. If no special measures are taken, it will run an expansion and compression always polytropic, whereby the polytropes are strong the adiabatic is approaching. In the case of polytropic, i.e. H. thus approximated adiabatic compression and elongation and a practically feasible and reasonable size of the heat exchanger the best overall efficiency is obtained at relatively low pressure conditions.

This fact has advantages, but also disadvantages. . Is beneficial it that the wall thicknesses of the lines. the compressor and the turbine can be kept small. Furthermore, you get to the turbine with fewer steps and the compressor, which is particularly important for the compressors. there t% -e, -en of the large flow rates. which are required for internal combustion turbine systems, almost exclusively flow fans and here again primarily axial compressors come into question. The more multi-stage such a compressor becomes. the steeper. so unforteillia.fter the characteristic is. It is therefore desirable. that the pressure ratio does not get too high.

In this working method described above, the So turbine: with a small gradient. To get a certain service, However, the processed gas weight must be large with a small gradient. The pipelines. the turbine, etc. are thus made large in size. For small and medium-sized systems Size may not weigh that fact very much. With large systems it can however question the feasibility at all. You then get such large ones required Ouersclinitte. that they are only finite and practically impracticable Could realize blade and rotor dimensions.

Gas turbine systems have now been built with a closed circuit, ie systems in which the same gas is compressed in a compressor, heated in a heat exchanger, expanded in a turbine and cooled in a second heat exchanger with a subsequent air cooler. With such an arrangement, by raising the entire pressure level, the circulating gas volume can be greatly reduced, so that the greatest power can be generated with acceptable dimensions of the individual parts of the system. However, it can be explained that such a gas turbine system is made up of very many parts. You need a second heat exchanger and a much larger combustion chamber, as this is operated under atmospheric pressure. But if it is to be operated with higher pressure. then another air compressor is required. Furthermore, an 'aftercooler acted upon with water must be arranged for the circulating air. so that the air enters the compressor at approximately the Ratini temperature. Such a system is regulated by changing the pressure level of the circulating air. When the pressure drops, air is blown off, and when the pressure rises, air is also fed into the circuit, so that a special regulating compressor is also required. After the invention "these difficulties are overcome; the task. to create a high performance facility. is achieved by the joint application of the following features known per se: 2 an selects an internal combustion turbine process. in which the air is isothermally compressed and the combustion gases are isothermally expanded or the isothermal energy is achieved as far as possible in both cases. An isothermal compression can also be combined with an adiabatic or polytropic or an adiabatic or polytropic compression with an isothermal expansion. With isothermal compression and also with isothermal expansion, the most favorable degrees of efficiency are at high pressure ratios. As a result of the great gradient, only a small air or air gap is required to achieve a certain performance. Gas weight to be processed. The isotropic compression is achieved in a known manner by removing heat. that is, by cooling the compressor and by intercooling. The intercooling proves to be very effective, but it has the disadvantage that the pressure loss is relatively low and the construction is very large. It is therefore civilized. only get along with the compressor cooling. One can hardly fully realize the isotherm with this, however: it is also sufficient if the isotherm is only approximately realized.

When stretching, one strives for the isotherine. that one in known `` '' also during the expansion in the turbine through the arrangement of intermediate combustion chambers the temperature lowered in the previous stage or stages down to the initial value elevated. However, this ',' experience causes pressure losses and a multi-part design. The isothermal expansion ink can also be achieved by heating the turbine housing, if not completely come, at least approximate.

F_in another step to achieve great performance in the turbine is. according to the division of the turbine output into the compressor output and in the useful power. the arrangement of a special turbine for each output, which are both connected in parallel. As a result, there is only flow through each turbine part of the total amount of gas, so that the dimensions of each turbine become smaller hzw. you can achieve greater performance with the largest possible design of the turbines can. as if only a single turbine for the compressor output and useful output would be provided. The separation of the turbine power into -compressor- and useful- power also has the large VOT part of the better control option.

Then the turbines and possibly also the compressor Double-flow design and the axial flow speed through the turbine as well as by the compressor strongly, d. H. to at least 100 m / sec. elevated. Even as a result, while the blade length remains the same, the blade flowing through the turbine becomes The amount of gas and thus the output of the turbine system is increased.

The invention thus consists in the joint application of the following known characteristics: i. Isothermal or approximately isothermal compression and / or expansion, 2. Division of the turbine power into two parallel-connected Turbines, 3rd double-flow design of the turbines and possibly also of the compressor and q .. high axial flow velocity, d. H. at least 100 m / sec Tut-binen and compressors.

Each of these features sets the upper performance limit for internal combustion turbines up. The joint application brings another shift as an additional effect the performance limit in that each of the features 2, 3 and q. the approach to the isotherm allows much better, because by the subdivision of the turbine power and through the double flow the cooling or heating surface and through the increase the flow rate increases the heat transfer coefficient.

Claims (2)

PATENT CLAIM: Internal combustion turbine system of high performance, marked through the joint application of the following characteristics, which are known per se: i.Isothermal or approximately isothermal compression and / or expansion, 2. Distribution of the turbine power on two parallel-connected turbines, 3rd double-flow turbine design and possibly also of the compressor and q .. high axial flow velocity, d. H. at least 100 m / sec., through turbines and compressors.