US1813921A - Vapor power plant - Google Patents

Description

Jul 14, 1931. w UM; 1,813,921

VAPOR POWER PLANT Filed Nov. 3, 1928 Candy/vale Patented July 14, 1931 UNITED STATES PATENT orifice WILHELM GUMZ, or BERLIN-CHARLOTTENBURG, GERMANY, ASSIGNOR 'ro sIEMENs sonucxnnrwnnxn AKTIENGESELLSCHAFT, or BERLIN-SIEMENSSTADT, GERMANY,

A CORPORATION OF GERMANY VAPOR POWER PLANT Application filed November 3, 1928, Serial No. 317,094, and in Germany November 4, 1927.

My invention relates to improvements in vapor power plants, and more particularly to means for regulating the furnace ofv such plants by controlling the supply of oxygen to the combustion air in dependence of the load in such a manner, that the supply of oxygen is increased, when the load rises and decreased when the load drops. 7

It has heretofore been proposed to increase the supply of fuel when the load rises and to introduce more air in correspondence with the increased quantity of fuel. In this way it is substantially possible to adapt the furnace to any output demanded, but this mode of regulation requires a. considerable tlme. When by the dropping of the steam pressure or the dropping of the steam temperature the regulating process is initiated, the supply of fuel and air is first increased by means of suitable apparatus. The increased supply of fuel causes in grate furnaces a thickening of the layer of fuel located upon the grate. Although the supply of air is adapted to this increased quantity of fuel, a certain time will elapse before the oxygen of the air is able to reach all the combustible particles of this thick layer of fuel, and the combustion becomes perfect. Only when the combustion is perfect an increased transfer of heat can take place to the boiler and can show itself 1n the condition of the steam generated.

For certain steam generating plants this delay may be of little importance, but on the other hand it has a great effect on boilers subjected to great load fluctuations, and which have not sufiicient steam storage space or accumulation capacity to temporarily cover these sudden demands of steam. In such cases the regulation of the supply of fuel is only a very unsatisfactory expedient. If,

on the other hand, according to my invention the addition of oxygen to the combustion air is increased without any substantial change of the quantity of fuel when the load rises, the perfect combustion of the fuel brought about thereby increases the heat radiation from the grate towards the boiler. At the same time the heat exchange from the flue gases to the boiler is improved, because the flue gases contain a higher proportion of carbon dioxideand this gas possesses a particular good heat transmitting quality in com-.

parison with nitrogen, the second main constituent of the waste gases. If the contents of oxygen in the combustion air is increased from 21 per cent, i. e. the contents of the ordifurnace is increased by about 100 per cent. It is obvious that by means of my invention sudden very high peak loads may be instantly covered, without having to take into account a time lag of the regulating action behind the release or initiation of the regulation process. 7 I

Preferably the regulation is carried out in such a way, that not only the addition of oxygen is regulated, but simultaneously also the quantity of the combustion air, in such a way, that it is varied in the reverse ratio to the quantity of the oxygen. The quantity of the ballast gases, such as nitrogen, traversing the boilerff-urnace uselessly is thus reduced. It is well known that nitrogen, which forms of the air supplied to the furnace, does not take part in the combustion process and is quitev immaterial to it. The supply of an increased quantity of oxygen will thus greatly improve the efficiency of the furnace.

In the drawing affixed hereto and forming part ofmy specification an embodiment of my invention is illustrated diagrammatically.

Referrin to this drawing, 1 is a fire tube boiler, whic is fired with pit coal in the usual manner, and supplies the steam to a steam turbine 2 coupled with a dynamo 3. Normal combustion air is fed into the ashpit of the boiler furnace through a pipe 4. This air may be delivered by a fan, blower or from an air receptacle (not shown here). Through a pipe 5 oxygen may be withdrawn from a steel flask or other receptacle 12 and added to the combustion air. The control of the supply of air and oxygen takes place by a control device, which responds to changes in the condition or quantity of the steam. It is immaterial for my invention, whether the control gear of this device'is connected to the output governor of the steam turbine or to a device in communication with the steam supply pipe 7 in which latter case it would be adapted to respond to variation of the steam. In the example illustrated a pressure responsive control device 14 is shown in communication with steam. main 7 and which through a system. of levers 6, 8 and. 9 operates the valves 10 and 11, in such a manner, that when the pressure of the steam rises the quantity of the oxygen is reduced and the quantity of air" increased.

Various modifications and changes may be made without departing from the spirit and the scope of the invention.

I claim as my invention: I I

1. In a power plant in combination, a vapor generator, a furnace for said generator, a receptacle for oxygen, a conduit between said receptacle and said furnace, means. for con trolling the flow of oxygen to said furnace in relation to the load; on the generator, means for supplying. normal. combustion air to said furnace, and means connected to the oxygen control means, for automatically varying the air supply to said furnace with the variation of. the oxygen supply. 2. In apower plant inco-mhination, a vapor generator, a furnace for said generator, a receptacle for oxygen, a conduit between said receptacle and said furnace, means for controlling the flow of oxygen to said furnace in accordance with the load on the generator, means for supplying normal combustion air to said. furnace, and means connected. to the oxygen control means for regulating the combustion air flow to the furnace inversely to the oxygen flow;

In testimony whereof. I aflix my signature.

WILHELM GUMZ.

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