US1982060A - Conservation of heat within a steam power system - Google Patents

Description

Nov. 27, 1934. J. M-cCALLUM ET AL 1,982,060

CONSERVATION OF HEAT WITHIN A STEAM POWER SYSTEM Filed Dec. 22, 1931 2 Sheets-Sheet 1 20 Fig.2.

Nov. 27, 1934. .J McCALLUM ET AL 1,982,060

CONSERVATION OF HEAT WITHIN A STEAM POWER SYSTEM Filed Dec. 22, 1931 2 Sheets-Sheet 2 wm/rms Ja n! Mt. CCL/llgm H PemivaJ f/mrye; Anderson y Patented Nov. 27, 1934 'umren STATES CONSERVATION OF HEAT WITHIN A STEAM POWER SYSTEM John McCallum, Glasgow, Scotland, and Harry Percival Harvey Anderson, Surbiton, England Application December 22, 1931, Serial No. 582,608 In Great Britain August 7, 1925 11 Claims.

This application is a continuation in part of our application Serial No. 97,472, filed March 25, 1926 for Conservation of heat within steam power systems. Our invention differs from prior arrangements in that whilst the exhaust steam is returned to the steam generator by pumping means, the said steam during its passage from the engine to the generator as hereinafter explained is not allowed to expand freely but is confined. More particularly, the exhaust steam is conducted to a receiver (such as a length or lengths of pipe of small diameter) in which its pressure falls somewhat and its temperature is positively reduced a few degrees 15 by heat abstracting means (such as continuously flowing cold water applied to the exterior of the receiver) the drop in pressure and temperature being only sufiicient partially to condense the steam and form steam-water i. e., steam mixed '20 with water. Thereafter the water is drawn off by pumping means of which the capacity is not greater than the receiver, the uncondensed steam being entrained with the water and thereby passed back again into the generator.

The temperature of the receiver is maintained as constant as possible and to enable this to be done in accordance with the pressure of the exhaust steam from the engine, the flow of cooling water is under valve control (such as a diaphragm valve acted upon by the exhaust steam).

It is important that the steam entering the receiver be only partially condensed before being drawn off as it is necessary to entrain as much steam as possible with the water so as to return as much of the latent heat as possible to the generator. It has been found that the steamwater can be readily pumped into the water space of a generator in which the steam is maintained at a much higher pressure.

Briefly, therefore, the invention consists in providing means for the conservation of heat within a steam power system, comprising, in combination, a steam generator; a steam power unit driven by steam from the said generator; a relatively small receiver, such as a length (or lengths) of pipe of small diameter, for the exhaust steam from the steam power unit; means for abstracting heat from the exhaust steam entering the receiver so as to reduce the temperature of the said steam; means for regulating the rate of such heat abstraction in accordance with the pressure of the exhaust steam from the steam power unit, the stem in the receiver being converted into steam-water by being subjected simultaneously to the action of the heat abstracting means, and

to the compressive effect of fresh quantities of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and means for returning the steamwater to the water space of the steam generator, 60 the exhaust steam not being allowed to expand freely but being confined during its passage from the steam power unit to the steam generator.

The formation of steam-water in the above circumstances is explained as follows:--

Let the original temperature and pressure of the steam in the receiver be h and p1 respectively, and let t2 and m respectively representthe temperature and pressure of the exhaust from the steam power unit. When fresh exhaust steam enters the receiver, the temperature of the resulting mixture of steam will tend to assume the value t1, the temperature of the steam already in the receiver. Similarly the resulting pressure would tend to assume the value 101, the pressure of the steam in the receiver. But steam at a temperature t2 and a pressure 112 is being continually supplied to the receiver by the exhaust of the steam power unit. Hence, the volume being constant and heat being abstracted from the steam by the cooling means, the pressure in corresponding to the temperature t1 can only be attained by the deposition of water from the exhaust steam, which deposition accordingly takes place when the exhaust steam enters the receiver.

The invention will now be described by way of example, and with reference to the annexed drawings, in which: I

Fig. 1 is a diagrammatic plan view of one form of steam power system embodying the features of our invention.

Fig. 2 shows the exhaust steam receiver and pertaining parts in sectional elevation. I

Fig. 3 is a view similar to Fig. 1 but of a modification.

Throughout the drawings the same references denote the same or similar parts.

Referring first more particularly to Figs. 1 and 2, numeral 1 denotes the generator from which 109 high pressure steam is supplied, through the steam pipe 2, to the steam power unit 3, here represented as a single cylinder reciprocating engine. After doing work in known manner in the unit 3 the steam passes, by the exhaust pipe 4, to the exhaust steam receiver 5 provided with a restricted outlet 5*. As shown in Fig. 2, the receiver 5 consists of a system of inverted U- shaped pipes 5 open at their one end to an inlet 15 in Communication with the aforesaid exhaust 110 pipe 4 and at their other end to the aforesaid restricted outlet 5*, the inlet 15 and the outlet 5 being separated by the partition 15 The receiver 5 is jacketed at 6, and cold water from a suitable supply source, represented as a tank 6 in Fig. 1, is allowed to flow constantly through the jacket,.entering by way of the pipe 14 and leaving by the pipe '6". The rateof flow ofcooling water through the jacket 6 is determined by a valve 14 which is controlled automatically by the action of the exhaust steam from the steam power unit 3. To this end the .valve propenis connected by a rod 16 to a lever l7 ;pivoted at 18 on a diaphragm box 20 containing a diaphragm 19 with a projecting pin lQ bearing-againSt-a finger l7 depending rigidly "from the lever 17 which has an adjustable loading =.-.w,ei ght 17= Steam from the exhaust pipe 45has access by way of pipe 21, to the interior of the diaphragm box 20 at one side of the diaphragm. It'is evident. that deflection of the. diaphragm 19 under th steam. essu e raisesthe leve .17 about .its pivot, byre asonof the. contact ,of thediaphragm ,rinAB and manager 17 thereby opening the valve 14 an amount proportional ,to the steam pressu e- As the outlet. endfitof. thereceiver ,5 is. reduced the steam cannot escape .freely .from .the .receiver but isconfined ordelayed therein and while being so delayed it isfiGtQd on by the coolingwater circulated, thllQl h .the jacket 6. and its temperature lowered. below that of ,the exhaust. steam in the .pipe A of the system, .the .combined action pf the compressive effect of the fresh quantities of .entering steam and thesudden reduction of the .temperaturecausing .the steam in the receiver 5 to be. converted, into steam-water which is drawnofi by the pipe Rand \returnedby the pump,,8.directly.to .the waterspace of thegenerat'or 1. The purnpfijs shQwnasa reciprocatingpump having ,itscrankshaft B operatively connected .with the crank shaft 3 of .the steam Powe u i 3 .Th c nn c ionma mp e .a suitably journalled shaft3 coupledat 3 to the crankshaft 3 and having .a .chain vwheel 3 round .whichand a similar-chain .wheel 8 on .a shaft 8 coupled atBF to ,the crank shaft .8 there pas a .d vms hai fie {Ilhe receiver ,5 .is not of large capacity .and, as its. outlet 5 is reduced, the .water ,of condensation in passing through the reduced outlet entrains ,the uncondensed steamwith it, the steam and at p ssi t t ump 8,. which is of smaller capacity than the receiver.5,.and thence to the generator. it is important that the .receiver 5 should .be-. o,f small diameter so that the cooling Water circulating through the jacket .6 will quickly .act on the steam ,and partially .oondense t e condensate bein .draw off .as .it is for-med and entraining .a-..coinparati vely large volume of uncondensed steam. The temperature of ,the receiver 5 should ,be constantly maintained below that of the exhaust steam in the pipe 4 and in p a tice we hav f und that a te p ture .of about 5' F. lower than that of the exhaust steam in .4 is desirable.

In the modification illustrated by Fig. 3 the steam from .the generator 1 pa ses by the pipe Sand branch 9* to the steam power unit 3. The exhaust steam from the .unit .3 is led by pipe 10 to a pump 11 .the motor 12 .of which is driven by steam obtained irom the generator 1 by way of the aforesaid pipe 9 and a second branch 9. Th st am frqmt e pum 11 is d into h haust st am recei er a et P p and the steam from the pump motor 12 is also led into the exhaust steam receiver 5 by pipe 13. As fully described with reference to Figs. .1 and 2, the receiver 5 is water jacketed at 6. The steam-water formed in the receiver 5 is returned to the steam generator 1 by the pipe 7 and pump 8 as before.

With the arrangements described in the foregoing it has been found by experiment that while there is a certain loss due to the back pressure iii the exhaust of the steam power unit, there is -a-marked-acceleration of the generating action of the boiler and a consequent saving in fuel. By introducing a pump 11, 12 as in Fig. 3, the back pressureon. theJengine may be reduced.

'In order'that the invention may be carried readily into effect, we shall refer briefly to the particulars. observed in the construction and operation of one embodiment comprising a single cylinder reciprocating engine.

The-lever .17 is balanced by the weight 17 to give aflow of cooling water through the jacket 6 surrounding the receiver-5 at theapproximate rate of four pounds of Water per minute, correspondingtothe flow at vthe .sametime of one pound. of exhaust steam. The ,lever 17 .has .a downwardly. depending member 17 .thereon ter- .minating in a cam. shapedlface 17- against' which .the,horizontallyextending. rodmember 19 which is connected with diaphragm .19abuts. Asdia- ,phragm 19 ismoved toward the left .under :increased steam .pressurerod 1 9 moves against .the cam face ,1 7.of,-downwardly-depending member .17 tendingto .raiselever 17and open the valve between-the volume of the receiver 5 and the volume .of the .engine cyllinder -is approximately as 1 .isto .3. During the operation of the engine, the rate of flow of the cooling Water is regue lated toapproximately the value abovespecified by an .inlet valve which is actuated, in known manner, in accordance with the variationsof the exhauststeampressure.

The feed pump for removing the so-called steam-water from the receiver is of the reciprocating type and is arranged so that the relative volumes of the .pump barrel and engine cylinder are approximately in the proportion of l to 33. The area of .the constriction at the bottom of the receiver and of the conduit lead-.

ing from the receiver to the said feed pump is made approximately equal to twice .the cross sectional area of a pipe suited to carry, under the same external conditions, ordinary water. The capacity of the said feed pump is kept in constant relationship with the discharge of the exhaust steam by driving the pump from the engine itself, or, should an independent drive for.

the pump be employed, by connecting the said drive to control means actuated in accordance with the fluctuations in pressure of the engine exhaust. To prevent loss 'of heat the said pump and its pipe connections may be lagged or insulated.

In starting up the system, the receiver may be heated, by admitting steam at 21 to a teme perature approximately equal to the temperature (about 240 F.) of the exhaust steam, but after the system has been in operation for a short time the exhaust steam will quickly impart heat to the surface of the receiver.

The steam generator of the system may be of any of the well known types, a vertical flue tube boiler being used in the present instance. As expelled from the engine, the steam (generated at 90 lbs; gauge pressure) has a resultant gauge pressure of 10 lbs., equivalent to a temperature of 240 F., and under these conditions the steam-water deposited in the receiver as before explained has a temperature of about 235 F., the initial and final temperatures of the water used to cool the receiver being approximately 50 F. and 190-200 F. respectively. It will be understood that the foregoing embodiment has been described merely by way of example and as showing what we have done experimentally and it is to be understood that we are not confining ourselves thereto but that various modifications and arrangements may be introduced, in so far as they fall within the scope of the appended claims.

This invention is peculiar in that a partial vacuum is not maintained in the receiver but a pressure which is somewhat less than the actual pressure of the exhaust and also that a temperature always somewhat less than the temperature of the exhaust is maintained constantly in the receiver the exhaust steam being passed rapidly to the receiver which is of comparatively small capacity so as not to permit of much expansion of the steam and to ensure that the whole body of the passing steam as it enters the receiver shall be reduced, in temperature, practically simultaneously throughout, when suddenly acted on by the cold produced by a heat abstracting means, such as constantly flowing water, the result being that the molecules of steam on entering the receiver are acted on by different pressures, the pressure in the receiver and the pressure in the exhaust pipe, and the reaction caused by the difference in pressure plus the drop in temperature, due to the sudden cooling action of the heat abstracting means, causesthe steam to be suddenly converted into a steam water (containing a large part of the latent heat of the steam) which can be passed directly by means of a pump, or otherwise, back again into the steam generator.

In certain respects the action is the reverse of the well known flash boiler in which water passing into small highly heated tubes is suddenly converted into steam.

We claim:-

1. Means for the conservation of heat within a'steam power system, comprising a steam gen-' the discharge of the exhaust steam, the steamin the receiver being converted into a mixture of steam and water by being subjected simultaneously to the action of the heat abstracting means and to the compressive effect of'fresh quantities of further exhaust steam at a higher temperature and pressure. than the steam already in the receiver; and means for delivering the mixture of steam and water directly to the water space of the steam generaton 2. Means for the conservation of heat'within a steam power system, comprising a steam generator having a water space therein; a steam power unit driven by steam from the generator; a receiver comprising a system of pipes of which the volume is smaller than the volume of the working chamber of the steam powerunit and into which the exhaust of the power unit is passed; means surrounding said system of pipes for efiecting the abstraction of heat from the exhaust steam in the receiver; a pipe line extending between the steam power unit and the heat abstracting means and having a pump interposed intermediate its length; means for regulating the rate of the heat abstraction in ac cordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and water by being subjected to the action of the heat abstracting means, the action of the aforesaid pump and the compressive effect of fresh quantities of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and means for returning the mixture of steam and water so formed directly to the water space of the steam generator.

' 3. Means for the conservation of heat within a steam power system, comprising a steam generator; a steam power unit driven by steam from the generator; a receiver comprising a system of pipes of-which the volume is smaller than the.

volume of the working chamber of the steam power unit and into which the exhaust of the power unit is passed; a chamber enclosing said system of pipes and providing a passage for the flow of liquid for effecting the abstraction'of heat from the exhaust steam in the receiver; means for regulating'the rate of such heat abstraction in accordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and Water by being subjected simultaneously to the action of the heat'abstraoting means and to the compressive effect of fresh quantities of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and a pipe line extending between the receiver and generator and having intermediate its length a pump driven from the steam power unit for returning the mixture of steam and water from the receiver to the generator.

4. Means for the conservation of heat within a steam power system, comprising a steam generator; a steam power unit driven by steam from the generator; a receiver comprising a' system of pipes of which the volume is smaller than the volume of the working chamber of the steam power unit and into which the exhaust of the power unit is passed; means enclosing said system of pipes for efiecting the abstraction of heat from the exhaust steam in the receiver; a pump interposed between the steam power unit and the heat ab stracting means and having an operating motor driven by steam from the generator; means for regulating the rate of such heat abstraction in accordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and water by being subjected to the action of the heat abstracting means,

the pump and the compressive efiect .of' fresh quantities'of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and a pump driven from the steam power unit for returning the mixture of steam and water from the receiver to the generator.

5. Means for the conservation of heat within a steam power system, comprising a steam generator having a water space therein; a steam power unit driven by steam from the generator; a receiver comprising a system ofpipes of which the volume is smaller than the volume of the working chamber of the steam power unit and into which the exhaust of the power unit is passed; a chamber enclosing said system of pipes and constituting a water jacket for effecting the abstraction of heat from the exhaust in the receiver; means for regulating the rate of such heat abstraction in accordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and water by being subjected simultaneously to the action of the heat abstracting means and to the compressive effect of fresh quantities of further exhaust steam at a higher temperature and pres sure than the steam already in the receiver, and means for returning the mixture of steam and water so formed directly to the water space of the steam generator.

6. Means for the conservation of heat within a steam power system, comprising a steam generator having a water space therein; a steam power unit driven by steam from the generator; a receiver comprising a systemof U-shaped pipes of which the volume is smaller than the volume of the working chamber of the steam power unit and into which the exhaust of the power unit is passed; a chamber enclosing said U-shaped pipes for effecting the circulation of a cooling fluid about: the pipes and causing the abstraction of heat from the exhaust steam in the receiver; a pump interposedbetween the steam power unit and the heat abstracting means; means for regulating the rate of the heat abstraction in accord- .ance with the discharge of the exhaust steam,

the steam in the receiver being converted into a mixture of steam and water by being subjected to the action of the heat abstracting means, the aforesaid pump and the compressive effect of fresh quantities of further exhaust steam. at a higher temperature and pressure than the steam already in the receiver; and means for returning the mixture of steam and water so formed directly to the water space of the steam generator, the

capacity of said last recited means varying relatively to the capacity of the power unit.

'7. Means for the conservation of heat within a steam power system, comprising a steam generator; a steam power unit driven by steam from the generator; a'receiver comprising a multiplicity of U-bend pipes of which the volume is smaller than the volume of the working chamber of the steam power unit and into which the exhaust of the power unit is passed; a chamber for cooling water surrounding said pipes for effecting the abstraction of heat from the exhaust steam in the receiver; means for regulating the rate.

of such heat abstraction in accordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and water by being subjected simultaneously to the action of the heat abstracting means and to the compressive eiTect of fresh quantities of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and a pump driven from the steam power unit for returning the mixture of steam and water from thereceiver to the generator.

8. Means for the conservation of heat within a steam power system, comprising a steam generator; a steam power unit driven by steam from the generator; a receiver comprising a system of pipes of which the volume is smaller than the volume of the working chamber of the steam power unit and into which the exhaust of the saidpower unit is passed; a fluid chamber surrounding said system of pipes for the circulation of cooling fluid around said pipes for effecting the abstraction of heat from theexhaust steam in the receiver; a pump interposed between the steam powerunit and the heat abstracting means; means for regulating the rate of such heat abstraction in accordance with the discharge of the exhaust steam, the steam in the receiver being converted into a mixture of steam and water by being subjected to the action of the heat ab stracting means, the pump and the compressive effect of fresh quantities of further exhaust steam at a higher temperature and pressure than the steam already in the receiver; and a pump driven from the steam power unit for returning" the water deposited in the receiver to the generator.

9. In a steam power system comprising a steam generator, a steam power unit driven by steam from the generator, and means for pumping back the exhaust from the power unit to the generator, the combination of a pipe system through which the exhaust passes to the pumping means and the volume of which is smaller than the volume'of the working chamberof the power unit, a cham-' ber enclosing the pipe system for circulating a cooling fluid'about the pipes, said chamber having cooling-fluidinlet and discharge connections, a valve disposed in the inlet connection} a diaphragm box, a diaphragm therein, means admitting exhaust from the power unit to the box to actuate the diaphragm in timed; relation to op eration of the power unit, and means operatively' connecting the diaphragm and the valve, where-- by the valve is opened and closed automatically in accordance with the prevailing steampressure and the cooling is regulated so that a mixture of steam and water is formed in the pipe system for return to thegenerator by the pumping means.

10. In a steam power system comprising a steam generator, a steam power unit driven by steam from the generator, and means for delivering ex-' haust from the power unit to the generatonthe combination of a pipe system through which the exhaust passes and the volume of which is smaller than the volume of the working chamber of the power unit, a fluid chamber enclosing the pipe system and having cooling-fluid inletand discharge connections, a valve disposed in the inlet connection, a diaphragm box, a diaphragm therein, means admitting exhaust from the'power unit to the box to actuate the diaphragm in timed relation to operation of the power unit, a'pin projecting from the diaphragm through the'box, a weighted lever pivoted adjacent the box,:means on the lever contacting with the pin to cause movement of the lever with the diaphragm, and means connecting the lever with the valve, whereby the valve is opened and closed in'ac'cordance with the prevailing steam pressure andthe cool-- ing 'is regulated so that a. mixture of steam and water is formed in the pipe system for return to the generator.

11. In a steam power system comprising a steam generator, a steam power unit driven by steam from the generator, and means for pumping back the exhaust from the power unit to the generator, the combination of a pipe system through which the exhaust passes to the pumping means and the volume of which is smaller than the volume of the working chamber of the power unit, a. chamber for a cooling fluid enclosing the pipe system and having cooling-fluid inlet and discharge connections, a valve disposed in the inlet connection, a diaphragm box mounted upon said

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