US1709997A - Steam-power plant - Google Patents

Description

April 23, 1929. w, NQACK 1,709,997

STEAM POWER PLANT Filed Nov. 21, 1924 Patented Apr. 23, 1929.

UNITED STATE WALTER GUSTAV NOACK, or Y scnnrr BROWN,

S PATENT OFFICE.

STEAM-rowan PLANT. 1

Application filed November 21, 1924, Serial No.

to supply all the steam required for the sta-' tion, any additional quantity of steam required being supplied by low pressure steam boilers and this low pressure steam beingled to separate ordinary pressure engines (hereinafter referred to as low pressure en-' gines), or in the case of steam turbines as additional steam to the low pressure stages of the high pressure engine. In the high pressure engine (hereinafter referred to as the primary engine) the steam is expanded down to a pressure equal to that of the low pressure boiler and is then passed either directly to the low pressure engine or in the ease of steam turbines to the low pressure stages of the primary turbine or to the steam main of the low pressure boiler after having been previously brought, in most eases in secondary super-heaters, to the degree oi superheat of the low pressure steam. lily connecting the exhaust pipe of the primary engine with the steam main of the low pressure engines sudden variations in load are prevented from affecting thehigh pressure steam generators, which are not so well adaptedior supplying a varying quantity of steam, and are transferred to the low pressure boilers, which can more easily deal with variations in the load owing to their larger water and steam space and their lower pressure. But this connection to the steam main has several disadvantages which the present invention has for its object to obviate.

These disadvantages appear as soon as large variations in the load occur and the steam supply to the low pressure engines dit't'ers to a considerable extent. from normal.

it the low pressure engines cannot take all the exhaust. steam from the high pressure. engine. a return flow occurs to the low pressure boilers, the steam escaping through the safety valves thereof, Since this steam must pass through the secondary superheater and also through the superheater of the low pressure boilers, all the heat supplied in the superheaters is lost, when steam is blown 01?.

It has been proposed to lead the exhaust from a high pressure engine straight to low 151,266, and in Germany November 26, 1923.

pressure boilers and to supply the whole of the steam required by low pressure. on gines entirely from these boilers. But'this arrangement has, the disadvantage that the low pressure boilers must be always at work and unless they are kept fired it is impossible to maintain the plant in continuous operation.

Now the subject-matter of the invention provides meansto enable the high pressure and low pressure boilers to work in conjunction with the high pressure and low pressure engines so as to avoid the disadvantages of exhausting into the steam main and the low pressure boilers, but to retain the advantages of the two abovesmentioned methods of working. The new arrangement consists in dividing the exhaustpteampipe from the high pressure engine into two branches of which one leads to the low pressure engine and the other to thewater space of the low pressure boiler from which a second steam pipe is taken through a superheater to the low pressure engine. Nonreturn valves are provided to maintain the flow of the steam in the several pipes in the proper direction. The'steam entering the low pressure boilers is introduccd, for'example, through distributing nozzles for the purpose of distributing the heat of the steam rapidly through the water in the low pressure boilers and storing the maximum quantity" of steam.

The accompanying drawing illustrates diagrammatically a steam power installation in accordance with the invention. As here indicated, ais a high-pressure steam generator,sup lying a? high-pressure turbine primary tulgiine) b, c 0 are low pres sure turbines connected in parallehand (Z d d, d", are low pressure boilers with superheaters e, 6 e, a. The exhaust steam pipe from the primary turbine is denoted by f and discharges (for example) into the water space of the low ressure boilers d d, d, 11', through steam istributing nozzles g ,.g'-, g", g, At It a non-return valve is provided to prevent the return flow of water into the exhaust steam pipe of the rimary turbine under any circumstances.

he device designated by i is a s'uperheater, 7c is a non-return valve to revent the return flow of steam into the auxiliary steam pipe Z leading from the low pressure boilers and m is a pipe connecting the high pressure boiler ltiU with the low pressure boilers without passing through the primary turbine and n is a pressure-reducing valve that can be opened both automatically and by hand. The following working conditions may ocour in the plant illustrated in the boilers.

1. The generation of steam in the high pressure boiler a may be greatest load to be expected within the next few hours in which case all the steam will;

be supplied by the high pressure steam generator a and the low pressure boilers will be held in reserve for a later increase in the load.

primary turbine 6 passes either .directly or, if secondary superheating isi'necessary' through the secondary super eater i to'- the low pressure turbines c 0?. If the load decreases the steam that cannot be taken by the low pressure turbines flows through line 7 into the low pressure boilers d d d (2* and is condensed there whilst heating the Water If the load becomes still less, in which case the primary turbine is also affected, the high pressure steam flows through the pipe m to the low pressure boilers after having been reduced in pressure by means of the pressure reducing valve n.

2. The generation of steam in the high pressure boiler may not be suflicient for the maximum load. In this case a portion of the low pressure boilers is under steam and aportion is held in reserve.- The steam from the primary turbine 6 passes through the secondary superheater 2' into the low pressure turbines and if a still larger quantity of steam is required for the low pressure turbines this low pressure steam is supplied by the low pressure boilers (I d d (1* through the steam main Z. \Vhen the load decreases the surplus exhaust steam from the primary turbine flows through the pipe f to the low pressure boilers'and is stored therein.

3. The steam required may have to be supplied by the high and low pressure boilers togethe A In this case flie exhaust steam from the primary turbine 6 passes through the superheater z'into the low pressure turbines and at the same time steam flows into the low pressure turbinesfrom the steam main Z. In the event of the load being suddenly reduced the safety valves-of the low pressure boilers will blow off.

What I claim is 1. A power plant installation comprising in combination a high pressure steam generator, a high pressure steam engine supplied therefrom, a low pressure steam gen- .steam passed from sufficient for the pressure engine to :fGIatOI, a low pressure connectlons from the j pressure steam engine In that case the exhaust steam from erator, a low connections from the exhaust of the high pressure steam engine to the low pressure steam generator and to the low pressure steam engine, a steam connection from the low pressure steam generator to the low pressure steam engine, and means for heating the exhaust of the high the low pressure engine. 2. A power plant installation comprising in combination a high pressure steam generator, a high pressure steam engine supplied therefrom, a low pressure steam gensteam engine, steam exhaust of the high to the water space of the low pressure steam generator and to the low pressure steam engine, a superheater between the high and the low pressure steam engines and a steam connection from the low pressure steam generator to the low pres sure steam engine, the connection to said water space providing communication between the same and the exhaust of the high pressure steam engine independently of said superheater. 3. A power plant installation comprising in erator, .a highpressure steam engine supplied therefrom, a low pressure steam gen,- erator, a low pressure steam engine, a steam connection from the exhaust of the high pressure steam engine having two branches, one to the low pressure steam generator and one to the low superheater in the branch to the low pressure steam engine, a superheater connected to the low pressure steam generator and a steam connection from the last mentioned superheater to the low pressure steanrengine.

4. A power plant installation comprising pressure steam engine, steam combination a high pressure steam genpressure steam engine, a Y

in combination a high pressure steam generator, a high pressure steam engine supplied therefrom, a low pressure steam generator, a low pressure steam engine, a steam connection from the exhaust of the high pressure steam engine having two branches one to the low pressure steam generator and one to the low pressure steam engine, a non-return valve in the branch to the low pressure steam generator, a superheater in the branch to the low pressure steam engine, a superheater connected to the low pressure steam generator, a steam connection from the last mentioned superheater to the low pressure steam engine and a nonreturn valve in this steam connection.

Dated this 7th day of November, 1924.

WQ G. NOACK.

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