US1967755A - Control for vapor-generators - Google Patents

Description

y 4, 1934. R. o. JUNKINS 1,967,755

CONTROL FOR VAPOR GENERATORS Filed Feb. 26, 1932 2 Sheets-Sheet l INVENTOR o fIf V/MM y 1934- R. D. JUNKINS 1,967,755

CONTROL FOR VAPOR GENERATORS Filed Feb. 26. 19 52 2 Sheets-Sheet 2 INVENTOR m WWW a Fig.2.

Patented July 24, 1934 UNITED STATES PATENT OFFICE CONTROL FOR VAPOR-GENERATORS Raymond D. Junkins, Cleveland Heights, Ohio,

assignor to Bailey Meter Company. a corporation of Delaware This invention relates to a method and means for controlling the operation of vapor generators or boilers, and has particular reference to that type of vapor generator wherein a plurality of liquids are separately vaporized either by heat transfer from the combustion of fuel, or by heat transfer from one of the fluids to another. Such vapor generators are known wherein are vaporized two fluids having different characteristics such as density and vaporization temperature, and have been commonly called binary vapor generators.

In the ordinary power plant utilizing, for example, the heat liberated by combustion to generate steam and then condensing the steam after it has passed through a steam turbine, there is a considerable heat loss for a large quantity of heat at a low potential is carried away-by the condenser cooling water. The lower limit of temperature and pressure, that is to say, the temperature and pressure-of the steam condenser, is in general rather definitely fixed by the temperature of the cooling water available, and the upper limit of temperature is generally limited by the 25 ditliculty of mechanically handling and confining steam at high pressures and temperatures, which is a much more serious problem than that of handling high pressures at comparatively low temperatures or of handling high temperatures at comparatively low pressures.

The efficiency of such a heat transfer system may be increased by increasing the temperature range through which it works. and it is for this reason that steam turbines have been constructed to operated at higher temperatures and higher steam pressures. Mercury as a vaporable fluid, howev r, offers decided advantages over water in that high temperatures can be obtained without the necessityof high pressure. For example,mercur-y boils at about 677 degrees F; at atmospheric pressure, while mercury vapor at'a temperature of 950 degrees F. has a pressure of'only .125 pounds gage, whereas steam at a temperature of only 570 degrees F. ha a pressure of about 1200 pounds gage. Saturated mercury vapor may thus be obtained with a considerably higher heat content at a materially lower pressure than saturated steam.

The so-called binary vapor generator system has most commonly utilized water and mercury as the vaporable liquids,'the mercury'in closed cycle. Mercury is vaporized through the heat of combustion, passed through a mercury vapor turbine and to a condenser from which it returns as a liquid to the mercury vapor generator. The

mercury vapor condenser is effect a steam generating boiler from which steam so generated passes to a turbine 01'' other desirable point of usage. Thus a considerable portion of the low potential heat ordinarily lost in the condenser is made available through the vaporization of the second liquid.

In vapor generators. of the character mentioned, wherein a plurality of fluids are vaporized either through the liberation of heat of combustion or through heat transferred from one fluid to the other; the supply of the elements of combustion to the related furnace must-be continuous and at all times proportional to the demand v or output of the unit; and further, should be so proportioned one to the'other that best efliciency of combustion is obtained. I provide, as explained hereinafter, a method and means for controlling the operation of such vapor generators in accordance with an indication of varying conditions in their operation, such for example, as fluid pressure, temperature, rate of flow, etc.

In the art of electricity generation and distri-- bution, experience has demonstrated that the highest overall system efliciency is-obtained if the most eificient equipment is operated at a high constant rating and if the rating 'on'the less elficient equipment is varied to maintain the total energy generated equal to the energy demand. It is, therefore, common central station'practice today to set the most efficient equipment to carry a certain predetermined base load and to continually readjust, either by hand or automatically, the load carried by the less eflicient generat-.

-ing equipment to take the swings in the total therefore, contemplate or be so" arranged that.

at the will of the operator the unit may be controlled to maintain a constant predetermined energy output, or an output varying in accordance with changes in a condition indicative of variations in total load on the-system. Thus, a condition would be, for example, the pressure of one of the vapors' used as a heat transfer medium, or the total flow of such a vapor, or the total elec- ,trical output, etc.

Inasmuch as a binary vapor generating imit H0 is, as heretofore explained, a unit of high efficiency, I have found it is usually advantageous to operate the unit to obtain a desired electrical output of the mercury turbine driven generator, and I desirably use such output as an indication for proper and primary control of feed of the elements of combustion to the furnace. Simultaneously, however, I desirably maintain a relation established between the vapor outflow from one of the fluids being vaporized with the air flow to the generator for the purpose of readjusting the supply of one of the elements of combustion to result in most eflicient combustion. I have further found that it is desirable to initially control the supply of the elements of combustion to the furnace to maintain at a predetermined value the mercury vapor pressure going to the mercury turbine and readiusting the supply of air from a relation between the rate of steam generated and the rate of air flow through the generator. 7

In connection with the operation of several multi-vapor generators or of a combination of multi-vapor generators with uni-vapor generators, I have found that it is desirable to effect a primary control of the elements of combustion to all of the related'generators from an indication of vapor pressure in a header common to all of the generators wherein is a fluid common to all of the generators, and in connection with such primary control I preferably readjust at each of the vapor generators the supply of one of the elements of combustion, preferably air, from a measure of the efficiency of combustion in that generator.

One object of my invention is to provide a method and means for controlling the operation of multi-vapor generators to obtain most efficient combustion of the elements of combustion in a furnace for heating the generator.

A further object is to so control the supply of the elements of combustion to a multi-vapor generator or generators that the total output is maintained at a desired value, and that the individual furnaces shall be operated at most eflicient combustion conditions.

Still further objects will become apparent from the specification, drawings and claims annexed hereto, and wherein I illustrate and describe the embodiment of my invention in connection with binary vapor generators employing mercury and water as the liquids to be vaporized.

In the illustrative embodiments of my invention I show herewith:

Fig. 1 is a sectional elevation of a binary vapor-generator according to the present invention, combined with the requisite apparatus to control the functioning thereof, and shown in partially diagrammatic fashion.

Fig. 2 is a diagrammatic showing of a battery of vapor generators. certain of which are multivapor generators and others of which are univapor generators; and with the requisite apparatus to control the functioning thereof in accordance with my invention.

In the drawings, identical parts bear the same reference numerals.

' Referring now in particular to Fig. 1, I have illustrated a binary vapor-generator in general at 3, having a furnace 4 for the heating thereof and in which combustion takes place between the elements of combustion fed thereto through a burner or burners 5. The furnace 4 is of a water cooled side wall, hot-bottom slag-tap type, wherein vertical cooling tubes 6 surround the furnace between horizontal top headers 7 and bottom headers 8. The liquid cooling tubes 6 are faced with refractory blocks or other material, indicated in general at 9, and the bottom of the furnace 4 is composed of suitable refractory material properly supported.

The arrangement is such that the furnace temperature is maintained at a level suificient to keep molten the ash or refuse from the elements of combustion, which molten refuse in slag form runs or drops to the furnace bottom where it collects and is periodically tapped through a tapping hole or spout 10.

Water for cooling the furnace 4 is fed from a drum 11 through a pipe 12 to the lower headers 8 for distribution to the tubes 6. Vapor or a mixture of vapor and liquid from the tubes 6 flows through headers 7 and a pipe 13 to the steam separating drum 11, from which the steam passes through a conduit 14.

The products of combustion from the furnace 4 pass upwardly in heat conducting relation, through various elements to be enumerated later, and are finally discharged to a stack through a duct 15 in which is positioned a damper 16 for control of the flow therethrough by a stop-start reversing pilot motor 17. Fuel for combustion, in the present embodiment being pul erized coal, is fed to the burner or burners 5 by a feeder 18 having a gate positioned by a pilot motor 19 for control of supply to the burner or burners.

Air for combustion is supplied to the burners by a fan 20 continuously rotated by a motor 21 whose speed is controlled through the agency of a rheostat 22 positioned by a pilot motor 23.

Primarily I provide a closed cycle wherein mercury is vaporized and condensed. The liquid mercury is first vaporizedthrough absorption of the heat liberated by combustion in the furnace 4, then the mercury vapor ispassed through a mercury turbine for performing useful work, and to condensing boilers where the mercury vapor is condensed to a liquid and returned tothe vaporizing portion of the cycle. The mercury vapor condensers are actually steaming boilers wherein the heat remaining in the mercury vapor after it has passed through the mercury va por turbine is transmitted to the second fluid, namely water, for generating steam from the 'water.

An upper portion of the furnace 4 is surrounded by vertical wall cooling tubes 24 connectedto headers 25 and from the headers to a mercury vapor separating drum 26 which is in the path of the heated gases, and from which depend closed end tubes 27 in known manner for bringing liquid mercury in heat absorbing relation with the gaseous products of combustion.

The drum or drums 26 comprise vapor separating means from which mercury vapor at, for

example, 125 lb. gage, 958 degrees F., passes through a conduit 28 to a mercury vapor turbine 29 adapted to drive through its shaft 30 an electric generator 31. An electrical instrument such as a watt-meter 33 providedwith an indicating pointer 34 cooperating with an index 35 is provided to indicate the output of the generator 31 as a measure of the output of the turbine 29.

In the conduit 28 a weight or otherwise loaded safety device such as a valve 36 allows a direct bleeding through a conduit 37 of the mercury vapor pressure in the conduit 28 above a predetermined value. Exhaust mercury vapor from the turbine 29 passes through a conduit 40 to the condensing boilers 38, 39 which are similar, and as shown in diagrammatic sectionat 39.

A tube sheet 41 traverses the condensing boiler and from the tube sheet depend tubes 42 around and in heat conducting relation with which is the mercury vapor entering through the conduit 40 or the conduit 3'! below the tube sheet 41. Above the tube sheet 41 and within the tube 42 which may be of U-shape, is the second liquid to be vaporized, namely water, whose approximate level is indicated at A. The mercury vapor is condensed and returned to the vapor generator through a conduit 43, a header 44 and a series of coiled tubes 45 to the drum 26. Thus the mercury in liquid and vapor form comprises a closed circuit wherein it is vaporized, passed through a turbine, condensed and returned to be vaporized again.

Water is supplied through a conduit 46 after first passing through an economizer heating section 4'1 comprised of a series of tube coils in the path of the products of combustion to the stack. From the conduit 46, branches lead to the condensing boilers 38, 39 and a branch conduit 48 supplies the drum 11 in the furnace cooling system. Water is led to the economizer section 47 through a conduit 49.

Steam generated in the condensing boilers 38, 39 passes therefrom through a conduit 50 which joins the conduit 14 and passes to a header 51, from which a series of coiled tubes forming a superheater section 52 is located within the path of the gases from the furnace 4. Steam leaving the superheater section 52 passes therefrom through a conduit 53 to a steam turbine 54 which through its shaft 55 drives an electric generator 57. The outflow of vapor from the superheater sectiori 52 through the conduit 53 is measured by a rate of flow meter 58 having an indicator pointer 59 arranged to cooperate with an index 60 forgiving an indication of the rate of fluid flow.

-The rate of flow meter 58 is of a known type such as is disclosed in the patent to Ledoux No. 1,064,748 granted June 17, 1913. Such a meter is a differential pressure responsive device adapted to correct for non-linear relation between differential pressure and rate of flow, to the end that angular positioning of the arm 59 is by increments directly proportional to increments of rate of flow. I illustrate by dotted lines within the flow meter the outline of its internal construction wherein is a liquid sealed bell having walls of material thickness-and shaped as described and claimed in the above mentioned Ledoux patent. A pressure differential creatingdevice such as an orifice or flow nozzle is positioned within the conduit '53 and the rate of fiow meter 58 is connected to the conduit 53 at .opposite sides of such device.

It will be observed that I have progressively subjected to the heating of the furnace 4 and its products of combustion, a furnace water wall heating section 6 in which some vapor may be generated, a mercury heating and vaporizing:

section 24, 27, 26, a mercury liquid heating section 45, a steam superheating section St anda water economizer or heating section 47; The various sections are arranged in desirable relation to the heating and to the hot gaseous prodnets of combustion according to the range of temperatures of the heating gases at the different locations and the range of temperatures of the fluids in heat absorbing relation at those locations.

A certain amount of steam is generated in the water walls and separated out in the drum 11. Steam is generated in the condensing boilers 38, 39 and steam from the three separating surfaces 11, 38, 39 is brought together to pass through the superheating section 52 before going to the steam turbine 54.

In an installation comprising a single binary vapor-generator as described, wherein the mercury vapor passes through a turbine such as 29 and all of the steam generated may pass through a turbine 54, I desirably control the operation of the system to maintain an established load upon the unit as a whole or an established load upon the mercury turbine alone, in which event the steam generated is considered more or less as a by-product. To accomplish a loading of the unit as a whole in accordance with an impressed or desired rate of output of the mercury turbine driven generator 31, to a power system to which the generator 31 feeds, I so adjust a lever or similar device 62, having a pointer 63 cooperating with an index 64, that the indicator reads on the index 54 the value of the electrical output desired.

An electric contact making device such as a contactor bar 65 is adapted to be oscillated around a pivot point 66 intermediate its ends and at one end is pivotally connected through a link 67 with a point intermediate the ends of a floating beam 68. The beam 68 is connected at one end pivotally through a link 69 with the indicator 63, while at the other end it is connected pivotally through a link '70 with the indicator 34. The arrangement is such that when the link 67 is moved vertically, contact '71 or contact 72 is close circuited. for completing an electric circuit to be presently described.-

When I desire to change the electrical output of the generator 31, I position the lever 62 until the indicator 63 reads the desired output upon the index 64 and such positioning causes, for example, a lowering of the link 69 and consequently a lowering of the link 67. The result is a close circuiting of the contact '72 which will result in changing the supply of the elements of combustion to the furnace 4 in amount suflicient to change the output of the generator3l in direction and amount whereby the link 70 will be raised an amount suflicient to cause a return of the contactor bar 65 to its previous open circuit position.

Thereafter, whenever the actual output of the generator 31 departs from thatv valueestablished on the index 64, there will be a close circuiting of the contact 71 .or the contact 72 for correcting the supply of the elements of combustion in desired direction, and amount.

I llnd that I can'satisfactorily primarily control' the supply of the elements of combustion froman indication of mercury vapor pressure going 'to' the turbine 29 and in this connection I provide a Bourdon tube '13 connected through a pipe 74'with the conduit 28 and adapted to position a pointer 75' relative to an index' 76' as an indication of? mercury vapor pressure. vapor. pressure is one example of condition of the 'mercury' in; closed" cycle; wlficir vari'es with' the heating," and" maybe termed a condition of the" heating; I might equally as well utilize some other condition of the mercury or of the heating, such for example, as mercury vapor temperature. Carried by the Bourdon tube and positioned with Mercury" the pointer is a contact bar 77 adapted to be positioned around a pivot 78 intermediate its ends and for the purpose of close circuiting the contacts 79,80 upon departure of the mercury vapor pressure from desired or predetermined value.

Selective between the contactors 65 and 77 I position, in the neutral wire thereof, a selective switch 81 which may be positioned by hand to select for automatic control of the elements of combustion supplied to the furnace, between the contactor actuated by the electrical output of the generator 31 or by mercury vapor pressure in the conduit 28. Furthermore, by throwing the selective switch 81 to an intermediate or non-contacting position (as illustrated) I disconnect the automatic control from either of the variables and allow the possibility of push button control, to be mentioned later.

The selective switch 81 is connected to a power line 82. One-half of each of the contacts 71, 79 are connected together and through a conductor 83 led through a normally close circuited contact 84 to a solenoid coil 85 from which a return conductor 86 joins the other power line 87.

One-half each of the contacts 72, is connected through a conductor 88 through a normally close-circuited contact 89 to energize a solenoid coil 90 and return to the power line 87.

The arrangement is such that if an increase in the rate of supply of the elements of combustion is desired, the relay solenoid 90 is energized through a close-circuiting of the contacts 72 or 80, while if a decrease in the rate of supply of elements of combustion is desired, then the close circuiting of either the contacts 71 or the contacts 79 results in an energization of the solenoid 85.

Provision for shunting the kilowatt output contactor 65 or the mercury vapor pressure contactor 77 by hand push button control of the relays and 90,' are shown a push button station 91 for energizing the solenoid 85, and a push button 92 for energizing the solenoid 90. These push buttons may be actuated regardless of whether the selective switch 81 is in either contacting position or in a non-contacting position.

The normaly close circuited contacts 89, 84 are interlocking contacts between the solenoid coils 85, 90, to the end that when one of the coils is energized, the related contact is open-circuited to the end that the opposite solenoid cannot be at the same time energized, thus preventing the possibility of one of the push buttons 91, 92 calling for an increase in the rate of supply of the elements of combustion when one of the contactors above mentioned might call for a decrease in the rate of supply.

The relays 85, are adapted to cause an energization in a less and a more direction respectively of the pilot motors 17, 19 and 23, controlling respectively the induced draft, fuel supply and forced draft to the generating unit. By energization in a less direction, I mean an energization of the said motors which will cause them to decrease the rate of supply of the elements of combustion to the furnace. In other words, to move the damper 16 and the gate of the feeder 18 toward a closed position and to decrease the speed of the fan 20. By energization in a more direction, I means an energization of the said motors which will effect movement of the damper and-feeder gate toward an open position and increase the speed of the fan 20. The pilot motor 17 has a conductor 93 joining it to the power line 82, and two conductors 94, 95 adapted when energized to cause a rotation of the pilot motor 17 in a less and a more direction respectively.

The pilot motor 19 is joined by a conductor 96 with the conductor 95. The pilot motor 23 is joined to the conductor 95 which then leads to a normally open-circuited contact 97 of the relay 90 which when actuated closes circuit to the conductor 86 and power line 87.

The conductor 94 is joined by a conductor 98 to the pilot motors 19 and 23 and to an opencircuited contact 99 of the relay 85. When the contact 99 is close-circuited, then the conductors 98, 94 are joined through the conductor 86 with the power line 87.

A return line 100 connects the pilot motors 19, 23 to the normally open-circuited contacts 101, 102 of the relays 85, 90 respectively, from which wires lead to the power line 82.

It will be seen that while the normally opencircuited contacts 9'7, 99 control the energization and direction of the pilot motor 17, they require in addition the cooperation of the opencircuited contacts 101, 102 for an energization indesired direction of the pilot motors 19, 23.

In addition to the primary control of the supply of the elements of combustion to the furnace 4 from an indication of the output of the generator 31 or of mercury vapor pressure within the conduit 28, I have found that it is desirable toreadjust the induced draft through a positioning of the damper 16 and consequently cause a readjustment in the rate of supply of air for combustion in order to obtain the desired efficiency of combustion. In this connection I utilize a well known method of comparing an indication of output of the unit with an indication of air flow through the unit, and upon departure of such relation from desired ratio, cause a readjustment in the supply of air.

By air flow through the vapor generating unit from the furnace 4 to the outlet duct 15, I intend to mean not only the excess of air existing as such, but also the products of combustion and in fact, any gases carried along this path for possible heat transfer to the fluids being heated or vaporized within the various sections previously enumerated, which are in heat absorbing relation with the gases.

I obtain a measure of the air flow through a differential pressure responsive air flow meter 103, having a pair of liquid sealed inverted bells suspended from an oscillatable beam 104, pivoted intermediate its ends and having at one end a pointer cooperating with an index for providing an indication of air flow.

Leading to within the bells of the meter 103 are pipes 106, 107 connecting with the path of the gases in spaced relation and as I have shown, to be responsive to the pressure drop across the tube sections 45, 52, 47. I further provide the oscillatable beam 104 with a displacer depending into mercury and having a shaped cross-sectional area, so that the positioning of the indicator relative to the index 105 is by increments directly proportional to increments of rate of flow of air, through a correction of the quadratic relation existing between rate of flow and differential pressure.

Positioned by the beam 104 is a pivotally connected vertical link 108 joining at its lower end, one end of a freely floating beam 110, which at its other end is pivotally connected to a link 109 pivotally suspended from the steam flow meter arm 59. The beam 110 is then positioned in space according to steam flow and air flow, and from apoint intermediate its ends depends a pivotally connected link 111 which is moved vertically upon departure of the steam flowair flow relation from predetermined value. To the lower end of the link 111 is connected one end of an oscillatable contact bar 112 pivoted intermediate its ends and carrying one-half each of normally open-circuited contacts 113, 114.

The contact beam 112 is connected through a conductor 115 in series through the normally close-circuited contacts 116, 117 with the power line 87. The other half of contact 113 is connected through conductor 94, conductor 98, normally open-circuited contact 99,.and conductor 86 to the power line 87; while the other half of the contact 114 is connected through conductor 95, normally open-circuited contact 97, and conductor 86 to the power line 87. Thus the normally close circuited contacts 116, 11'! provide energization from the power line 8'! to the contactor beam 112 except when either the relay or the relay is energized, thereby breaking the contact 116 or 117 to prevent energization ofthe contacts 113, 114.

In general it will be seen that I have provided a parallel control of induced draft, forced draft and fuel supply selectively from three sources, all of which serve to control the relays 85, 90 which when energized dictate an increase or a decrease in the rate of supply of the elements of combustion. I may at any time energize the relays 85, 90 through the hand operated push buttons 92, 91. I may selectively automatically energize the relays 85, 90 from the contactor 65 positioned responsive to the kilowatt output of the mercury vapor turbo-generator or from the contactor '17 positioned responsive to mercury vapor pressure.

I provide by the contactor 112 a means responsive to the relation between steam flow and air flow for causing a control of the induced draft only to effect most efllcient combustion through a balancing of the supply of air with an indication of generator output. I so arrange the electrical circuit that normally the steam flow-air flow contactor is effective to adjust the induced draft damper, but that when either the relay 85 or the relay 90 is energized from one of the selective sources for a parallel control of the elements of combustion, this energization through an opening of the contacts 116 or 117 makes ineffective for the time being the contactor 112.

I have found that for controlling the efliciency of combustion through supplying the proper amount of air in accordance with the heat liberation, it is satisfactory and desirable to utilize a measure of the steam leaving the superheater section through the conduit 53 and that such steam being the total steam generated by the vapor generating unit as a whole is an accurate indication of the operation thereof, for regardless of the electrical output of the generator 31, such output cannot vary without a corresponding variation in the total amount of steam generated and passed to the superheater 52.

In general, then, and referring specifically to Fig. 1. I may load the unit through an adjustment of the lever 62 to desired kilowatt output of the generator 31 and automatically control the supply of induced draft, forced draft and fuel in parallel, with readjustments to satisfy combustion efliciency through the relation of steam flow to air flow effective to readjust the induced draft.

I may selectively cause a parallel control of the supply of the elements of combustion to maintain a predetermined mercury vapor pressure with readjustment of one of the elements of combustion from the steam flow-air flow relation.

I may by hand, through push buttons, cause an increase or decrease in the rate of supply of all of the elements of combustion, and after bringing the operation to a new level, allow the readjusting control of induced draft to function to satisfy combustion efliciency.

In Fig. 2 I illustrate a battery or plurality of vapor-generators, two of which are binary vaporgenerators and two are ordinary steam generating boilers. At A, B I show two mercury-steam vapor-generators similar to the one shown in greater detail on Fig. 1, while at C, D I show standard steam generators. In the vapor generators A, B the heated products of combustion pass from the furnace 4 successively in heating contact with the water heating and vaporizing section 6, the mercury heating and vaporizing section 24, the mercury heating section 45, the steam superheating section 52, and the water economizer heating section 4'1 to the damper 16.

An air flow meter 103 .and a steam flow meter 58 are provided, and from their related movements actuate a contactor 112 for readjusting control of the pilot motor 17. Primary parallel control of induced draft, forced draft and fuel supply through regulation of the pilot motors 1'7, 23 and 19 respectively, is accomplished through relays 85, 90 simultaneously, with a similar parallel control of the steam generating boilers C, D.

The closed mercury cycle for each of the boilers A, B is as in Fig. 1. The water is fed to the economizer section 4'! of each of the boilers .A, B through a conduit 49 from a common header 118 which through a branch 119 supplies the steam generating boiler C, and through a branch 120 supplies the steam generating boiler D.

Steam from the superheater section 52 of boiler A passes outward through a conduit 53, metered by a rate of flow meter 58 and through a valve 121 to a header 122. Steam from boiler B joins the header 122 in the same manner. Steam generated in the boiler C is passed through a superheater 123, a conduit 127, a valve 128, and a conduit 125 to the header 122. Steam generated in the boiler D is passed through a superheater 124 to the conduit 125 through a valve 126.

The total steam generated by the four boilers is measured in the header 122 by a flow meter 129 positioned in the header beyond the joining point of all of the boilers. Still further, in the direction of flow, the header 122 is joined by a conduit 139 leading through a valve 131 to a steam turbine 132 adapted to drive an electric generator 133. Through the closing, in the conduit 122, of a valve 134 beyond the joining point of the conduit 130, all of the steam generated by the four boilers A, B, C, D is passed to the turbine 132. If the valve 134 is open or in controlled position, a part of the total steam generated may pass through the header 122 beyond this valve to other desired usages.

- Connected to the steam header 122, through electric circuit of relays 85, 90, being connected thereto by conductors 88A, 83A respectively, interlocked through the relays as explained for Fig. 1. The return conductor 140 from the contactor bar 137 leads through a hand operable switch 141, in series through the push button stations 142, 143, through a conductor 144, and hence to the power line 82.

The push button 142 is adapted, when positioned downwardly, to break circuit and make ineffective the contactor 137 and simultaneously close circuit between the conductor 144 and the conductor 83A for energizing the relay 85, while if the push button 143 is moved downwardly, it likewise will break circuit to the contactor 137 and also close the circuit between the conductor 144 and the conductor 88A for energizing the relay 90. The push buttons 142, 143 thus provide a means for hand, remote actuation of the relays 85, and may be located as desired relative to the boilers or the relays. The switch 141 provides a possibility of disconnecting the four boilers from the parallel control of the Bourdon tube 136 through interrupting the common conductor 140, but without interfering with the possibility of push button control of relays 85, 90.

The return conductors of the four steam flow-air flow relation contactors 112 join together and pass in series through the normally close-circuited contact 116 of the relay 85, the normally close-circuited contact 11'? of the relay 90, the hand disconnect switch 145, and the conductor 146 to the power line 87. The hand switch allows the possibility of de-energizing the steam flowair flow contactors 112 of all of the boilers simultaneously, which with switch 141 disconnects all boilers from any automatic control illustrated. In the individual lines 115 I provide a single pole disconnect switch 153 for each boiler through whose agency the steam flow-air flow readjusting contactor for that particular boiler may be made ineffective when the related switch 153 is open-circuited.

For the individual boilers I provide at each a disconnecting switch 150 and a pair of push buttons 151, 152 whereby the particular boiler may be disconnected completely from the relays 85, 90 and be under push button control independently of all of the remaining boilers. I will describe in detail the functioning of the switch 150 and the push buttons 151, 152 in connection with boiler A only, as the functioning of the similar switches and push button stations for the boilers B, C, D is identical.

I have shown the switch 150 in open-circuit position wherein the conductors 115, 98a, 96a, 100 are disconnected from boiler A and thus boiler A is not susceptible to control from the relays 85, 90. In its shown open-circuited position the switch 150 has one blade, namely, that blade in the conductor 115, which contacts with a contact post 154 joined in series through the normally close circuited contacts 155 of push button station 152, the normally close circuited contacts 156 of push button station 151, and the conductor 157 to the power line 8'7. Assuming, then, that switch 153 is closed, the neutral connection 115 of the contactor 112 is energized from the power line 87, and if the contactor 112 is positioned in one direction or the other to cause a close circuiting of its contacts and upon a departure of the steam flow-air flow relation from unity, then the potential of the power line 87 is available, selectively by the contactor 112, at either conductor 98A or 96A for the pilot motor 1'7, the return conductor 93 leading to the power line 82. Thus in the shown arrangement of boiler A the induced draft damper 16 under the control of pilot motor 17 will be opened or closed by the agency of the contactor 112 as demanded by the steam flow-air flow relation.

Should the operator desire to change the rate of supply of induced draft, forced draft and fuel to the boiler A simultaneously and in parallel, he may do so through actuating push buttons 151 or 152, which respectively connect the three pilot motors to the power leads for desired direction of rotation, and at the same time break circuit at either 155 or 156 to disconnect the contactor 112. Thus if push button stations 151 or 152 are actuated, they produce a parallel control of induced draft, forced draft and fuel for boiler A, taking precedence over the contactor 112; but as soon as 'the push buttons are released and allowed to return to their shown positions, then the contactor 112 from steam fiow-air flow relation is available for controlling induced draft alone from such relation. If it were desired to disconnect even the contactor 112 from functioning, then the hand operable switch 153 may be opened to its shown position.

The arrangement is similar for boilers B, C, D, to provide maximum flexibility for the battery as a whole.

The apparatus and arrangement which I have described as illustrated in Fig. 2 is adapted to provide through the relays 85, 90 a parallel control of induced draft, forced draft and fuel supply to all of the boilers, automatically from an indication of steam pressure through the contactor 1 137, or by push buttons 142, 143. At the same time, at the individual boilers a steam flow-air flow relation contactor 112 readjusts the induced draft for each boiler individually and independently of the other boilers to attain most efficient combustion conditions for the particular boiler. However, the relays 85, 90 are arranged to take precedence over each and all of the steam fiow air flow contactors, whether such relays be actuated by the steam pressure contactor 137 or by the push buttons 142, 143.

Provision is made for disconnecting at each individual boiler, the pilot motors of that boiler from the relays 85, 90 and allowing for the individual boiler push button control of the elements of combustion in parallel with or without, as desired, the possibility of readjustment on induced draft control from the related steam flow air fiow contactor.

In connection with each of the binary vapor boilers A, B I provide an indicator 158 of mer cury vapor pressure, an indicator 33, 33A of mercury turbo-generator electrical output, an indicator 103 of air flow, and an indicator 58 of steam flow. By these various indications of variable conditions of the individual boilers, I may visualize the value of the variables in the operation thereof and employ my method and means for individual and/or automatic control of the boilers.

In connection with the uni-vapor boilers C. D I provide an indicator 159 of steam pressure, an indicator 103 of air flow, and an indicator 58 of steam flow.

Related to all of the boilers in the battery is the steam flow meter 129 which is adapted to advise the instantaneous value of the rate of flow of steam produced by all four of the boilers, which steam may all go to the turbine 132 or a part only thereto, and the remainder through the 150 valve 134 to other. points of usage. The Bourdon tube 136 sensitive to steam pressure in the header 122 is adapted to advise the instantaneous value of such pressure for either hand or automatic control.

I provide in connection with the mercury turbogenerator 31 of the boiler A an electrical measuring device such as a watt meter 33 having an indicator and index for advising the electrical output of the generator. The output conductors 61 lead from the watt meter 33 to a watt meter 333, having an indicator adapted to advise the total electrical output of all three electrical generators shown. The watt meter 33A of boiler B indicates the output of that boiler, while the watt meter 148 for the electrical generator 133 advises the electrical output of the steam driven generator. Watt meters 33, 33A and 148 all feed through the watt meter 333 having total outgoing conductors 149 and provided with an indicator for advising the total electrical output of the three electrical generators.

In Fig. 1 I show the electrical output conductors 61 leading from the watt meter 33 to a power system 61A which is also supplied with electricity by other generators as indicated by the feeding lines 613.

In Fig. 2 I show the electrical output lines 149 feeding system lines 149A which are also supplied from other generators or systems through conductors 149B.

In general, I desire it to be understood that while I have illustrated and described certain preferred embodiments of my invention, I am not to be limited thereto except as to the claims in view of prior art.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. The method of controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized, which includes the steps of controlling the heating of the first fluid in accordance with an indicat on of load on the closed cycle, and readjusting the heating in accordance with an indication of quantity of the second fluid vaporized.

2. The method of controlling the operation of a binary-vapor generating system wherein a first fluid is vaporized by the heat of combustion and a second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling the supply of elements of combustion in accordance with an indication of energy output of the first fluid, and readjusting the supply of one of the elements of combustion in accordance with a measure of quantity of the second fluid vaporized.

3. The method of controlling the operation of a binary-vapor generating system wherein a first fluid is vaporized by the heat of combustion and a second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling the supply of elements of combustion in accordance with an indication of energy output of the first fluid, and readjusting the supply of one of the elements of combustion in accordance with an indication of relation between rate of supply of an element of combustion and rate of second vapor outflow.

4. The method of controlling the operation of a binary-vapor generating system wherein a first fluid is vaporized by the heat of combustion and a second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling thesupply oi the elements of combustion in accordance with an indication of first fluid vapor pressure, and readjusting the supply of one of the elements of combustion in accordance with a measure of quantity of the second fluid va- 5. The method of controlling the operation of a binary-vapor generating system wherein a first fluid is vaporized by the heat of combustion and a second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling the supply of elements of combustion in accordance with an indication of a condition of the heating of the first fluid, and readjusting the supply of one of the elements of combustion in accordance with a measure of quantity of the second fluid vaporized.

6. The method of controlling the operation of a binary-vapor generating system wherein a first fluFd is vaporized by the heat of combustion and a. second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling the supply of elements of combustion in accordance with an indication of a condition of the heating of the first fluid, readjusting the supply of one of the elements of combustion in accordance with a measure of quantity of the second fluid vaporized, and allowing the controlling to take precedence over the readjusting.

7. The method of controlling the operation of a binary-vapor generator heated by combustion and wherein one of the fluids travels in a closed circuit path, which includes the steps of converting a substantially constant percentage of the heat input into electrical energy by the agency of a first fluid in closedcycle, va'porizingm part of the second fluid by radiant heat in the furnace, vaporizing a part of the second fluid through condensation of the first fluid, measuring and indicating the amount of the second fluid vapor, measuring and indicating the flow of the products of combustion through the generator, and correlating such indications as a guide to regulation of an element of combustion.

8. The method of controlling the operation 01' a binary-vapor generator heated by combustion and wherein one of the fluids travels in a closed circuit path, which includes the steps of vaporizing a part of the second fluid by radiant heat in the furnace, vaporizing a part of the second fluid through condensation of the first fluid, measuring and indicating the amount of the second fluid vapor, measuring and indicating the flow of the products of combustion through the generator, and correlating such indications as a guide to regulation of an element of combustion.

9. The method of controlling the generation of power which consists in transmitting heat resulting from combustion to mercury and producing mercury vapor at a high temperature, converting a portion of the heat energy of the mercury vapor into mechanical work, condensing the mercury vapor and transferring its remaining heat of vaporization and its latent heat of condensation to a second fluid, utilizing a part of the heat energy in this second fluid to produce mechanical work, and automatically controlling the combustion in accordance with the mechanical work desired.

10. The method of controlling the operation of a binary-vapor generator which includes the steps of converting a substantially constant percentage of the heat energy input into mechanical work by a closed cycle of one fluid, vaporizing a portion of a second fluid by heat oi combustion and the remainder by condensation of the first fluid, in-

dicating the amount of the second fluid vaporized, indicating a condition of the heating, and correlating such indications as a guide for control of an element of combustion.

11. The method of controlling the operation of a battery of vapor generators at least one of which is a binary-vapor generator and the remainder of uni-vapor generation, which includes the steps of obtaining an indication of total energy output of the battery, controlling the heating of all of the vapor generators in parallel from such indication, separately obtaining an indication of output of each of the vapor generators, and separately readjusting the heating of each individual vapor generator from the related indication of output.

12. Apparatus for automatically controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, comprising in combination, means for supplying air and fuel for combustion for heating the first fluid, engine means for withdrawing energy from the closed cycle, a meter of such energy, electrical means made efiective by said meter for actuating said first-named means, a second meter for the vapor outflow of the second fluid, a third meter of air flow, ratio determining means coactively positioned by said second and third meters, and control means actuated by said ratio determining means effective for also actuating said first-named means.

13. Apparatus for automatically controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, comprising in combination, means for supplyingtair and fuel for combustion for heating the first fluid, engine means for withdrawing energy from the closed cycle, a meter of such energy, electrical means made efiective by said meter for actuating said first-named means, a second meter for the vapor outflow of the second fluid, a third meter of air flow, ratio determining means coactively positioned by said second and third meters, and control means actuated by said ratio determining means effective for also actuating said first-named means, said electrical means adapted to take precedence over said control means.

14. Apparatus for automatically controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, comprising in combination, means for supplying air and fuel for combustion for heating the first fluid, engine means for withdrawing energy from the closed cycle, a meter of such energy, an indicator of vapor pressure of the first fluid, electrical means selectively made effective by said meter or by said vapor pressure indicator for actuating said first-named means, hand-operable means for making such selection, a second meter for the vapor outflow of the second fluid, a third meter of air flow, ratio determining means coactively positioned by said second and third meters, and control means actuated by said ratio determining means effective for also actuating said first-named means.

15. Apparatus for automatically controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, comprising in combination, means for supplying the elements of combustion for heating the first fluid, means for continuously withdrawing a portion of the energy of 'the first fluid vapor, means for establishing a desired rate of withdrawal, and automatic means controlling the firstnamed means for maintaining the desired rate of withdrawal.

16. Apparatus for automatically controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, comprising in combination, means for supplying the elements of combustion for continuous heat input to the closed cycle, means for continuously withdrawing energy from the closed cycle, a meter of such withdrawn energy, hand-operable means for establishing a desired rate of energy withdrawal, and means coactively positioned by said meter and said hand-operable means for controlling said first-named means.

17. The method of controlling the operation of a binary-vapor generating system wherein a first fluid is vaporized by the heat of combustion and a second fluid is vaporized through condensation of the first fluid, which includes the steps of controlling the supply of elements of combustion in accordance with an indication of a condition of the heating of the first fluid, and readjusting the supply of one of the elements of combustion in accordance with an indication of relation between rate of supply of an element of combustion and rate of second vapor outflow.

18. The method of controlling the operation of a binary-vapor generating system wherein one fluid is successively vaporized and condensed in closed cycle and a second fluid is vaporized through the condensation of the first fluid, which includes the steps of vaporizing the first fluid by the elements of combustion, continuously withdrawing a portion of the energy of the first fluid vapor, and controlling the supply of the elements of combustion to maintain a desired rate of withdrawal.

RAYMOND D. JUNKINS.

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