US1709689A

US1709689A - Regulator system

Info

Publication number: US1709689A
Application number: US61811A
Authority: US
Inventors: Stephen A Staege
Original assignee: Westinghouse Electric and Manufacturing Co
Current assignee: CBS Corp
Priority date: 1925-10-10
Filing date: 1925-10-10
Publication date: 1929-04-16
Anticipated expiration: 1946-04-16

Description

April 16, 1929. 5 A, STAEGE 1,709,689

REGULATOR SYSTEM Filed 001'.. l0, 1925 -WITNES: v INVENTOR @77. S/e/ohen Aaeje.

Patented Apr. 16, 1929.

UNITED STATES PATENT OFFICE.

STEPHEN A. STAEGE, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE i ELECTRIC & MANUFACTURING COMPANY, A CORPORATIOL OF PENNSYLVANIA.

REGULATOR SYSTEM.

'Application led. October 10, 1925. Serial No. 61,811.

My invention relates to regulator systems and more particularly to compensating means for the governor mechanism of bleeder turbines. l

One object of my invention 1s to provide a bleeder turbine governor and bleeder mechanism with compensating means whereby a change in the amount of steam bled from the turbine will produce a corresponding change in lthe control valve opening, whereby the turbine will continue to carrysubstantially the same load without an appreciable change in speed.

rlhe term bleeder turbine is applied 'to that type of steam turbine comprising aseries of impulse blades for. receiving the initial steam pressure and a series of .reaction blades for receiving the steam at a lower pressure, and provided with a passage between the 1mpulse element and the reaction element for leading off steam from the turbine. rThis steam is led' from or bled from the turbine at a comparatively low pressure foroperating auxiliary apparatus or for process work, and as the pressure in the bleeder pipe varies in accordance with a Varying demand for use of the bled steam, a bleeder valve is operated to vary thewamount of steam bled from the turbine, so as to maintain a substantially constant steam pressure in the bleeder supply at the value for which it may be adjusted.

If a bleeder turbine drives an alternatingcurrent generator that is operated in parallel relation to other generators of the system, the turbine cannot appreciably change its speed unless the speed of the entire system changes, since the generators will normally remain in s ynchronism. As the bleeder turbine operates at a given load with agiven amount of steam being bled from theturbine, the steam required to lpass through the turbine control or inlet valve will in that case be a fixed quantity, depending upon the power required by the turbine.

As the bleeder valve opens, taking more steam from the turbine, it is necessary, in

order that the power output of the turbinec may remain unchanged, that the turbine control valve should also open to supply a greater quantity of steam to the turbine. It is obvious, therefore, that as the quantity of steam bled from the turbine is increased, the power output of the turbine will decrease,and, inasmuch as there is no appreciable change in speed, the governor mechanism will not operate to change the setting of the control Valve. Thel phase angle ofthe generator and turbine will fall back sufliciently to decrease the electrical output of the generator by the proper amount.

In order to overcome this diculty in the operation of a bleeder turbine, I propose to compensate for changes in load upon the turbine, caused by variations in the quantity of steam bled from the turbine, by changing the setting ofthe control valve in accordance with changes in load upon the generator. I make use of a small torque motor that is energized in accordance with the electrical load of the generator for operating a floating lever of the governor mechanism.

My invention will be better understood by reference to the accompanying drawing, in which rlhe single ligure is a 'diagrammatic view of apparatus comprising a preferred form of my invention.

A three-phase generator 1 is provided with an armature winding 2 and a eld winding 3, and is driven by a bleeder turbine 4 by suitable means such as ashaft 5. The tuibine 4 is provided with a steam supply pipe 6, an eX- liaiist pipe 7 and a bleeder pipe 8. The supply pipe 6 is provided with a control or inlet valve 9 that is operated from a pressure cylinder 10 in accordance with movements of apiston 11. Pressure is supplied to the cylinder 10 by means of

pipes

12 and 13, in accordance with the operation of a pilot valve 14.

The pilot valve 14 is provided with a pressure inlet pipe 15 and pressure outlet pipes 16 and 17, and with

pistons

18 and 19 that are controlled by a rod 21 to control the pressure that is supplied by the

pipes

12 and 13 to the opposite sides of the piston l1. A

he pilot valve rod 21 is pivotally connected to a floating lever 22, one end of which is controlled by a fly-ball governor 23 that is driven in accordance with the speed of the turbine 4. The opposite end of the floating lever 22 is provided with bifurcations 24 that are adapted to engage opposite sides of a cam member 25 that is connected by a shaft 26 to a torque motor-27. The torque motor is normally urged or biased to a definite position by means of a spring member 28, and operates to oppose the spring member, in accordance with current that is supplied from

current transformers

29 and 31. This current is proportional to the electric load of the generator 1, by reason of the connection of the current transformers to the three-phase supply-

circuit conductors

32, 33 and 34 for the generator.

The operation of the system is as follows: Assume that the bleeder turbine 4 is operating at a given load and that a certain quantity of steam is being bled from the turbine through pipe 8. As a greater demand for bled steam occurs, the turbine will tend to fall o' in speed but, on account of its beino' synchronized with the power system, it will do so onl to the extent of decreasing its phase ang e with respect to the system, and, consequentl the electrical output of the generator.

the generator causes a movement of the torque motor 27 by the spring 28 in a `counter-clockwise direction thereby raising the

pistons

18 and 19 and permitting pressure to flow from pipe 15 through pipe 13 to the under side of the piston 1,1 so as to open the control valve 9, thereby furnishin the necessary amount of steam to the turbine to maintain substantially the former load.

Similarl in case there is a decreased demand for bled steam, the turbine will tend to take on more load, thereby causing the generator to deliver a greater electrical load. This change in load on the generator will cause an angular movement of the torque motor in such direction as to partially close the control valve 9, thereby reducing the turbine load to substantially its former value.

1 It will be apparent then that the governor mechanism is so compensated that changes in the vquantity bf steam bled from the turbine will not result in changes in load upon the turbine.

Many modifications in the yapparatus and arrangement of parts may be made within the spirit of my invention, and I do not wish to be limited other than by the scope of the appended claims. 1

I claim as my invention t 1. In combination, a bleeder turbine, a speed governor for said turbine, means for bleeding steam from said turbine, and means responsive to changes in .the power output o' said turbine for changing the setting of his reduction'in load output of.

said governor to compensate for power losses \occas1oned b the bleeder action.

2. In com ination, a bleeder turbine, an electric generator driven by said turbine, a speed governor-'for controlling the flow of motive fluid to said turbine, and means responsive tos changes in the electric out ut of said generator for changing the setting of said governor to vary the input to said turbine in the reverse direction from the variation in generator output.

3. In combination, a bleeder turbine, an electric generator driven thereby, a speed governor tor controlling the iiow of motive iiuid to said turbine, and electro-responsive means for varying the setting of said governor to maintain a substantially constant generator load irrespective of the amount of motive fluid bled from said turbine.

4. In combination, a bleeder turbine, an electric generator driven thereby, a speed governor for controlling the How of motive fluid to said turbine, and electro-responsive means for changing the setting of said governor to compensate for power losses occasioned by the bleeder action.

5. In combination, a bleeder turbine, a valve for governing the How of motive fluid to said bleeder turbine, an electric generator driven by said turbine, a speed governor for controlling said valve, and electro-responsive means for effecting the operation of said valve in accordance with the output of said turbine to maintain a substantially constant generator load, irrespective of `the amount of motive fluid bled from said turbine.

6. In combination, a bleeder turbine, a valve for governing the flow of motive Huid to said bleeder turbine, a pilot valve for controlling the first named valve, an electric generator driven by said turbine, a speed governor for controlling said pilot valve, and electro-responsive means for actuating said pilot valve in accordance with the output of said turbine to compensate for power losses occasioned by the bleeder action.

In testimony whereof, I have hereunto subscribed my name this 24th day of September,

STEPHEN A. STAEGE.