US1654955A - Steam-accumulator plant - Google Patents

Description

Jan 3, 1928; v

v 1,654;955 w F. WETTSTEIN STEAM ACCUMULATOR PLANT Filed Nov. :50, 1925 s Sheets-Sheet 1 Q/ 7 WA;

#ZdvATTORNEY I BY Jan. 3, 1928.

F. WETTSTEIN STEAM ACCUMULATOR PLANT ed Nov. so, 1925 SSh'eets-Sheet "2 Comps/v.95?

firm/Mira INVENTOR' Pum a, ATTORNEY Jan. 3,1928, 1,654,955 F. WETTSTEIN v STEAM ACCUMULATOR PLANT Filed Nov; 30, 1925 s Sheets-Sheet s INVENTOR;

agd/mw 4&ATT0R EY Patented Jan. 3, T928.-

UNITED STATES'PATENT'OF'FICE.

rn'Irz wnrrsrnm,'-or SUMMIT, vnwunnsnv, ASSiGNdR To BUT-HS AccnmULA'ron. eomrany, me, on NEW YORK, 1v. Y., A conrormrron or DELAWARE.

" sm AM-AoouMULA'ron PLANT. 4

My invention relates to steam plants and 1 more particularly to plants where steam of high temperature is generated and in which-.-

storage of steam takes place so that the boilers may be operated independently of steam demand. I

The tendency in steam generation 1s toward higher temperatures and higher pressures. Steam boilers .can be built ofany desired pressure'hy use of boiler tubes of small diameter-but the nature of material used in boiler construction .is such that there is a limit of temperature above which it is not possible to generate steam.

According to the laws of thermo dynamics, the Carnot-cycle is the most eflicient cycle for thetransformation of heat energy into mechanical energy. The etficiency of this cycle ishigher, the higher the temperature is, at which heat is introduced into the cycle, and the lower the temperature is,

at which heat is taken off. The. lower temperature is, determined by the prevailing temperatureof the atmosphere' It therefore becomes. evident that, in order to increase the efliciency of the Carnot-cycle, the

upper value of temperature must be in creased. This holds good also for other cycles such as the Rankine-cycle because all of these cycles can be considered as the sum of infinitesimal Carnot-cycles. An arrangement which makes possible a definite and reliable control of the upper value of temperature of a cycle, and which thus elimi nates danger or prevents injury to materials which would result from excessive temperatures, is therefore highly desirable.

My invention provides such an arrange ment and includes means for maintaining temperature within any desired'limits while providing accumulation of. steam so that the plant may vrun with high eificiency. In certain cases I generate steam of conditions where pressure and temperature do not correspond. Pressure and temperature of steam have a definite relation to each other -only within the range of saturated steam.

For superheated steam, for hot water under pressure and for the range above critical pressure and temperature, where water and steam are gradually transformed into each other with no -definite line of separation between the two conditions, there exists no such definite relation between pressure andtemperature. It, therefore, onlythe pressure of steam is regulated, as'has been customary hitherto, a definite temperature is obtained within the range of saturated steam only, whereas, in the field oi hot water under pressure and of superheated steam, the temperature may deviate considerably from the desired or permissible value. With pressure control it is therefore not possible to control, for example, the generation of steam in such a Way that-a-constant temperature is maintained in the various ranges of hot water under pressure, saturated steam and superheated steam, as is desirable with certa n processes, such as, for example, the Carnot process. With temperature regulation however, as embodied in the present invention, the desired temperature may be maintained under all conditions, so that steam generation, for example, may take place close to the maximum temperature whichthe steam stand. 1

The invention .Wlll be readily understood by reference to the accompanying drawings generating apparatus will within which: Fig. 1 shows diagrammatically 'apower plant according to my invention; Fig.

2 is a diagrammatic illustration of the man- '9 nor of controlling the flow oii'steam to the low pressure section of the turbine illus trated in Fig. 1; Fig. 3 is a more or less diagrammatic showing of the control mechanism for the supply of steam to the turbine of Fig. 1; Fig. l shows a second form of plant constructed and arranged according to the invention; and Fig. 5 shows a according to the invention. I

' In Fig. 1, steam of high pressure and high temperature is generated in boiler 10 which may be of any type and which third plant may be fired in any desired way. The pres-- sure may be, for example, 4,000 lbs. per sq. in. and the temperature may be. 800 F. It is to be understood, however, that I do not limit myself to any values oft pressure and temperature. The pressure 13 maintained constant by means ot a reducing valve 11 in the boiler supply conduit 12. any of various known types of reducing valve may be use-r.-. For sake of illustration, 1 have shown i of How, valve 11 closes somewhat so that the pressure is reduced and, by such means, the pressure is maintained constant. l

The steam generated which normally superheated steam passes throi ah conduit 16 to a motor 17, in the present instance, a turbine. The turbine is of the condei'ising type havinga condenser 18. it is shown driving a load 19 consisting of an electric generator. The turbine has an extraction conduit 20 connected thereto to eed steam from between stages. Steam bled through extraction conduit 20 passes through a superhea't accumulator 21 containing any kind of material suitable "Eorthe storage of heat such as brick or metal and thence through conduit 22 and charge conduit 23 afi'ord accumulation to the extent desired.

Should the load on the turbine increase to such an extent that more steainis required than is for the moment generated in the boiler, steam can pass from the accumulator through conduit 22, through superheat accumulator 21 and-to the low pressure stages of the turbine. Steam may also be extracted from the accumulator through conduit 27. Steam condensate formed in condenser 18 is pumped by pump 28 to conduit 29 and into storage tank 80. 31 designates a malre-up line for the plant. From the storage tank water is' drawn through conduit 32 by pump 33 and is forced by the pump into supply conduit 12. Pump 33 may be of any of various types and may be driven in any desired manner. For the sake of illustration, a centrifugal pump is shown driven by an electric motor 34;. If desired the speed of the pump may be controlled but the pump can be driven at constant speed with the reducing valve 11 serving as the only regulating means. Any form of pump arrangement and pump control may be used but an arrangement should preferably be selected which maintains a constant supply pressure for the boiler. Supply of steam to turbine 17 is controlled by temperature in supply conduit 16 in such a manner that the temperature in conduit 16 is maintained constant. Proton ably, the turbine is controlled ly what is ucn is the case the control 0'. supply 01 known as mechanism of the, type indicated in 8.

In Fig. 3, 16 is the steam supply lineto the turbine. From conduit 16 steam passes into distributing chamber217 to which is connected a series or passages 218 leading to a series of nozzles 219 which direct steam into the passages of the first turbine wheel 20. Flow through passages 218 is controlled by means of a mechanism operated to successively connect said passages with distributinc chamber 21?. in the or ii shown, which to be understood as d1 amniatic to a considerable extent, this is accomplished by means of a piston 221 slidahlc in the distributing chamber .217. The arrangen'ient is such that as piston 221 moves downwardly closes oil the passages 218 one att r the the other in succession thereby changing of steam how to the urbine. This regulation is "on tble because supply of steam o' nigh pressure no without any .opreciable loss in hi i Any type or thermostatic regulation nay control the mechanism "for changing the cross-sectional area of flow of steam to the turbine. @ne term of mechanism is diagrammatically illust ated in 3 comprising a thern'iostatic bulb 222 situated in conduit 16 and acted upon by the super-heated steam passing through conduit ltlfrom the boiler and co iected by means of a tube 223 to a diaphragm housing 224-. Housing 2261 has attached thereto on one side a diaphragm 225 and contains a diaphragm chamber 326. Bulb 222, tube and cham her 326 contain an expansible or volatile fluid, preferably a liquid, which upon increase of temperature in conduit 16 expands, causing diaphragm 225 to lex upwardly as shown in Fig. 3. Movement of diaphragu'i 225 causes change of liquid pressure on the upper side of piston 226 as follows:

A. fluid such as oil is supplied throughconduit 227 and enters chamber 228 on the upper side of'piston 226 from which it passes out through conduit 229. Conduit 229 is connected to a housing 2210 which has an outflow opening 281 in the same, which opening is controlled by a batlling member movable across the opci'iing. Battling member 232 is formed on one end of a lever233 which is pivoted on a knife edge pivot at one end, indicated at 234. Movement of diaphragm 225 is transmitted to lever 233 through pin 235 and opposed to the pressure exerted on the vlcverby the diaphragm is a spring 236 which-rests between the lever and a lixed stud 237 which is arranged to be adjusted.

Opposed to the liquid pressure in chamber 228 is a spring 238. may be called a servo-motor; parts 230, 231,

team to the turbine may be effected by Parts 226, 228 and. 238

expands causing an increase of pressure in chamber 326, whereupon diaphragm 225 is flexed upwardly. This causes-a clockwise movement of lever 233 as shown, as a result of which bafiiing member 232 is caused to increase the flow through outlet 231 by uncovering the outlet to a greater extent. Increased outflow through outlet 231 results in decrease of pressure in chamben'228 whereupon piston 226 is moved upwardly under the preponderating force of spring- 238. As a result, piston 221 is also moved upwardly thus connecting some of the passages 218 with distributing chamber 217 so that more steam can .flow to the. turbine. This results'in a decrease of'temperature in conduit 16 since the flow of steam through the boiler is then at a greater rate and less heat is absorbed per .pound of steam.

Suppose on the other hand, that the .temperature in conduit 16 decreases. The fluid in bulb 222 then contracts and diaphragm 225- moves downwardly whereupon the out flow through outlet 231 is restricted. This. causes an increase of pressure in chamber 230, conduit 229 and chamber228 causing a downward movement of piston 226 and a closing of a greater or lessnumber of passages 218 whereby supply of steam to the turbine is decreased and the temperature rises to normal Value.

Flow of steam to the low pressure section of the turbine is controlled by a speed responsive governor controlling entrance to the stages just beyond extraction conduit 20. This speed'responsive governor is arranged so that it tends to maintai'na constant tur= bine speed. For sake of illustration, a diagrammatic view of this matter is presented in Fig. 2, although such regulation is known in the art. In Fig. 2, 39 designates the supply conduit to thelow pressure stages of the turbine beyond'extraction conduit 20. This conduit is controlled by a valve 40 which in turn is controlled by a centrifugal governor 41 operated from off the shaft of the turbine. The operation is such that when the speed of the turbine increases, centrifugal governor 41 acts to close valve 40 more or less and conversely, it the speed of the turbine decreases, the governor opens the valve more or less.

In Fig. 1 is shown a by-pass line 42 between supply conduit 16 and extraction conduit 20. This by-pass line contains a valve 43 operated by a thermostat 44 in front of the same, that is, on the side nearest the supply conduit 16. Expansion or contraction of fluid in thermostat-44 acts through conduit 45 on a diaphragm 46 so that upon increase of temperature the valve. tends to open. This valve is normally out of operation but comes into operation in case the temperature control for the high pressure section of the turbine should fail to admit sufficient steam to the turbine, or if the turbine cannot take more steam so that the temperature in con duit 16 should rise above the value normally maintained by the temperature control of the turbine.

In'Fig. 4 is shown a plant more or less similar to that shown in Fig. 1 except that; the steam passing through the accumulator does not first pass through a motor. In this case the motor is controlled by a centrifugat the valve opens. .For sake of illustration there is shown a bulb 50 in conduit 16 connected by means of tube 51 with a piston chamber 52. Upon increaseof temperature in conduit 16, fluid expands in parts 50,51

and 52 causing a movement to the left.

shown, of piston 53- against the action of spring 54 therebyopening valve 49 to the re quired amount to cause the 'temperature to decrease to normal value. In the plant shown in Fig. 4, the accumulator is adapted to supply steam through" conduit 55 to con-v sumers 57. Supply'of steam from the accumulator to conduit is controlled by a --reducing valve 56 which may beof any known type. The boiler in this case is shown as-comprised of a series of zigzag pipes. 'Obviously any number of types or boiler may be used within the scope of the invention. y

In the embodiment shown in Fig. 5 steam generated in boiler 60 passes into conduit 61 from which two conduits branch off in parallel. one, 63, leading to turbine 62 and the second, 64, leading to the accumulator 65. Flow of steam into turbine 62 from conduit 63 is controlled by a series of valves '66, 67, 68 and 69 which are adjusted to open successively in the order mentioned. Each of these valves is attached to a valve stem and each valve stem is attached to a motor. The motors for valves 66, 67 68 and 69 are numbered 70, 71, 72, and '7 3 respectively and Acting different strength, spring 78 being the weakest and spring 81 being the strongest. @ bviously valves 86 and 67 with their relative operations may be interchanged since they control supply of steam to the same wheel 125. Pipe 83 is open at. the point 80 and the opening thereof is controlled by a batfiing member 8? is moved by diaphragm 92 in conduit 83, and consequently in coi'idu' comprising one side of a housing 93 which is connected by means of conduits 94 and with athermostatic bulb 96. also conduits 9-1 and 95 and the inner space of housing 93 contain an expansible fluid, preferably a volatile liquid.

Consideringthe' parts thus far described without reference to other cooperative parts,

the operation is follows: Upon a slight increase in temperature in conduit 61 the fluid in bulb 96 expands and there results an increase of pressure on diaphragm 92 which serves to decrease the outflow of oil through opening 80. The pressure in conduit 83 is thus increased and assumingl at lirst that all of the valves 66, 67, 68 and 69 are closed, the first effect will be to overcome the res ance of the weakest spring 78 whereupon piston 71 will be moved to open valve 60. Upon further increase 01 pressure in conduit "3 and connecting conduits, piston 75 will be moved to open valve 67. Upon further in crease of pressure in conduit 83 result of continuing high temperature in conduit 01, valve 68. controlling supply oiisteam to the second wheel 97' of the turbine, is opened. and upon still further increase of pressure 84 and 85, valve 69 controlling supply or steam to the turbine stage 98 is, opened. The reverse operation due to decrease of temperature in conduit 61 will be readily understood :t'rom the above description.

The valves above described are controlled not alone by temperature of steam but also by the speed of rotation of turbine through the agency of the following apparatus: Conduit 100 has an opening 102 in the same which is controlled by a ball'hng member 103. Bal'l'ling member 103 is controlled by a centrifugal governor 104: comprising balls pivoted to swing outwardly upon increase of centrifugal effect due to an increase of speed and connections with ballling member 103 to move the same away from opening 102 upon increase of speed. The centrit ugal governor is shown diagrammatically as operated from the turbine shaft 105 by means of bevel gears 106. Oil spraying out of opening 102 collectsin receptacle 10? and This bulb and is conveyed back into 90 by means 01? i conduits 10S and 89.

Steam passes from. accumulator 65 through conduit 109 and conduit 01- into housing 110 which contains two valves 111 and 112 controlling supply of steam to two oi? the lower pressure stages of the turbine but not by delivery to the same stage; that is, valve 111 delivers to a low pressure sta e 118 and valve 112 delivers steam to a still lower stage 11 1-. These valves 111 and 112 are controlled by pistons 115 and 116 respectively which are acted upoirby pressure of oil conveyed through conduits 117 and 118. Opposed to the oil pressure are springs 119 and 120 of whichspring 119 is the weaker so that valve 111 operates ahead of valve 112 upon increase ot pressure in conduit 117. The purpose of this arrangement is to admit accumulator steam first to the higher pressure stage on discharge of the accumulator and conduit which is also controlled by bailling member The action of valves 110 and 111 under the influence or the centrifugal governor is as follows: Suppose the speed decreases to the point at which spring 119 is adjusted to yield. Then ballling member 103 throttles the outflow 01" oil through 123 to such an extent that oil pressure in conduit 117 is increased to overcome spring 119 whereupon valve 111 is unseated and steam passes from accumulator 65, through conduits 109 and 0-1, through alve 111 and to stage 113. Upon further decrease of speed, oil pressure in conduits 11? and 118 rises so that valve 112 is opened. It is desirable that when valve 112 opens, that valve 111 shall immediately shut. This may be done as shown on the drawing by causing a valve 126 operatively connected to piston 116 to provide passage of motive fluid from conduit 117 to the spring side of piston 115 so that the oil pressures are equalized to some extent and spring 119 preponderates. Upon reclosing of valve 112, valve 126 connects the spring side of piston 115 withan outflow conduit 1 10.

To complete the regulation there is arranged in conduit 61 a temperature controlled valve 128 operated by piston 129 on the one side of which oil pressure acts, the oil 1 being supplied through conduits 130 and 13 messes The action of the complete regulation may .be described as follows: Assumethat each of valves 66 and 67 are open but that valves 68 and 69, 111' and 112 are closed. Now assume that the temperature risesin conduit 61. Rise of temperature in conduit 61 causes an expansion of fluid in bulb 96, con- 85. This will have no effect on valves 66,

duits 95 and 94 and housing 93, whereby opening 86 is restricted and there is an in creasein pressurain conduits 82, 83, 84 and to increase in supply of steam, the speed of turbine increases. Centrifugal governor at which opening 86 was throttled.

104 then raises baffling member 103 to increase the outflow of liquid through opening 102 and consequently there is a decrease of pressure in conduits 100, 101, 82, 83, 84

and 85, the result of which is a closing of some or all of valves controlling admission to stages. 12,5, 97 and 98. These valves will close in succession, valve 69 closing first; then valve 68 then valve 67, and, last, valve 66. Suppose that the increase of speed and the consequent closing of one or more of the control valves for the high temperature steam causes an increase of temperature in conduit 61 higher than g at 1aphragm 136 is then moved to restrict opening134 whereupon pressure in conduit 130 and on piston 129 increases so that valve 128 is opened and steam is by-passed through conduit 64, through check valve 129 and into the water space of the accumulator 65.

Assume onthe other hand, that the temperature in conduit 61 drops. Bafiiing member 135 is first caused to recede from opening 134 as a result of which valve 128 becomes closed, thus cuttin off the supply to the accumulator and irecting all the steam to the turbine. The effect of throttling of opening 86 before opening 134 can be effected in the stiftness'of diaphragms 92 and 136, or may be effected by other means.

' On further drop of temperaturethe outflow all these valves, last mentioned, being open, .the speed is not up to normal.

Centrifugal governor 104 then operates to decrease the outflow through opening, 123. This causes a rise of pressure in conduit 117 which rise of pressureacts on piston 115 to open valve 111. Steam then flows from accumulator further decrease of speed the consequent rise of pressure in conduits 117 and 118 piston 116 is operated to open valve 112- and steam then flows from the accumulator to the interstage chamber ahead of stage 114.

In this modification, as in those previously described, I prefer tolcontrol the supply of feed .water to the boiler 60 by means of a above disclosure without departing from the spirit and scope of the invention.

Having thus described my invention, what I claim is:

' 1. A high pressure boiler, an accumulator,

a passage for superheated steamfrom said boiler to said accumulator, and automatic temperature responsive valve mechanism to simultaneously maintain a constant temperature in said boiler and to control flow of superheated steam through said passage.

2. In a steam plant, in combination, a high pressure boiler adapted to produce superheated steam, an accumulator, a conduit for conducting superheated steam from said boiler toward said accumulato a valve in said conduit, and temperatur responsive means to operate'said valve to increase the flowof steam through said "valve upon increase of temperature in said boiler and decrease the flow of steam through said valve upon decrease of temperature in said boiler.

3. In a steam plant, in combination, a boiler, an accumulator, a conduit for passage of steam from said boiler to said accumulator, a main control memberin said conduit to control flow of steam from said boiler to said accumulator, a liquid pressure operated V servo-motor to control said main control member, a relay to control said servo-motor, said relay COIIIPI'lSlDg' a member. having an outlet therein for the outflow of a liquid- .and means to control the outflow of liquid through said outlet, and a thermostat to operate said relay to increase the flow of steam through said conduit upon increase of temperature in, said "conduit ahead of said" main control member and decrease the flow through said conduit upon decrease of temperature in said conduit ahead of said main control member.

4. In a steam plant, in combination, a steam boiler, means to supply feed water to said boiler, means to maintain the pressure of said. water constant, an accumulator, a

passage for steam from sai'dboiler tosaid accumulator, and means responsive to the temperature of steam leaving said boiler to control flow of steam from said boiler to said accumulator.

5.' In a steam plant, in combination, a boiler, an accumulator, a passage for steam from said boiler to said accumulator, temperature responsive means to control flow through said passage to maintain a constant temperature of steam in said boiler, and pressure operated means operating to main tain a constant pressure in said boiler.

6. In a steam plant, in combination, a boiler, a feed Water supply conduit for said boiler, a reducing valve in said feed Water supply conduit, a steam supply pipe for said boiler and temperature responsive means in said steam supply pipe operating to main tain a constant temperature in said boiler.

7. Method of producing and dispensing steam in a steam plant which comprises raising a body of water to a given pressure, applying heat to said body of Water to transform the same into steam at a rate'diflerent than the rate of steam demand, with drawing steam at a rate such that the temperature of steam generated. is maintained constant, accumulating steam in amounts equal to the difference between steam withdrawal and steam demand and utilizing the steam accumulated when the demand for steam is greater than the rate of steam Withdrawal.

'8. In a steam plant, in combination, a source of superheated steam, an accumulator, a passage for superheated steam from said source to said accumulator and a thermostat controlled valve in said passage operating to maintain a constant temperature in the source.

9. In the steam plant, in combination, a source of steam, amotor supplied with steam from said source, a plurality of valves controlling admission of steam to said motor, and means responsive to temperature in said source to operate said valves successively to maintain said temperature constant.

10. lln a steam plant, in combination, a source of steam, a motor supplied from said source, an accumulator supplied with steamfrom said source, means to conduct steam from said accumulator to said motor, a plurality of valves controlling admission of steam to said motor, means responsive to temperature in said source to operate said valves successively to maintain said temperature constant and meansto control flow of steam from said accumulator to said motor.

11. In a steam plant, in combination, a steam boiler, a feed Water supply conduit for said boiler, means to maintain the pressure in said feed Water supply conduit and said boiler constant, a motor, means to conduct steam from said boiler to said motor, and means responsive to the temperature of steam leaving said boiler to control fiOW of steam from said boiler to said motor.

12. In a steam. plant, in combii steam boiler, a -.eed Water supply con: lit for said boiler,

a reducing valve in said teed reassess Water supply conduit,- a-motor, means to conduct steam from said boiler to said motor, and means responsive to the temperature of steam generated in said boiler to control flow of steam to said motor.

13. In a steam plant, in combination, a source of high temperature steam, a motor including high pressure stages and low pressure stages supplied from said source, a plurality ot valves controlling admission of steam to said high pressure stages, means rcsponsive to temperature in said source to close said valves successively upon drop of temperature, a source of 10W pressure steam, means to conduct steam from the last men tioned source to said low pressure stages, a plurality ofvalves controlling admission of steam to said low pressure stages and means to open the last mentioned valves successively upon decrease of speed of said motor.

14. In a steam plant, in combination, a source of high temperature steam, a motor including high pressure stages and low pressure stages supplied from said source, a plurality of valves controlling admission of steam to said high pressure stages, means responsive to temperature in said source to close said valves successively upon drop of temperature. an a(.'ciunulator, means to conduct steam from said source to said accumulator, means to conduct steam from said ac cumulator to said low pressure stages, a plura-lity of valves controlling admission of steam to said low pressure stages and means to open the last mentioned valves successively upon decrease of speed of said motor.

15. In a steam plant, in combination, a motor having a plurality of stages, an ac cumulator, means to conduct steam from said accumulator to several of the motor stages of dill'erent pressures, s iarate valve mechanisms to control admissn to the difi ercnt stages and means to close a valve mechanism for a given stage when a valve mechanism for a lowerpressure stage opens,

ltl-ln a steam plant, in combination, a boiler adapted to produce steam of unrelated temperatureand pressure conditions, an ac cumulator, a conduit for conducting said steam from said boiler toward said accumu later, a valve in said conduit and temperaturc responsive means to operate said valve to increase the flow of steam through said -valve upon increase of the temperature of said steam and to decrease the tloiv of steam through said valve upon decrease of temperature of said steam.

In testimony whereof I have atlixed my signature.

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