SE181677C1

SE181677C1 -

Info

Publication number: SE181677C1
Authority: SE
Publication date: 1962-01-01

Description

Uppfinnare: J R Mc Entee och R S Cooper Foreliggande uppfinning avser en varmevaxlaranlaggning innefattande tva varmevaxlare, vilka efter varandra genomgas av en gasstrom, vars temperatur skall regleras, varvid en gasrenings- eller dylika gasbehandlingsanordningar ar inskjuten mellan varmevaxlarna i gasens stromningsbana, och vilka aven genomstrommas av gaser, som genom att avge eller upptaga varme reglera den forstnamnda gasstrOmmens temperatur. Effektiviteten t. ex. has elektrostatiska gasrenare beror pa am behandlingen av gaserna i renaren sker vid jamfOrelsevis hoga temperaturer, sã att de i gasstrOmmen svavande partiklarna icke uppsamla fuktighet och latt kunna utskiljas ur gasstrommen. I samband armed fordras for effektiv verkan hos en anggenerator, t. ex. vid en kraftanlaggning, att de slutligen utgaende gasernas temperatur nedsattes till ett sh lagt varde som praktiskt ar mojligt formedelst en varmevaxlaranordning, bestaende av luftforvarmare vilka forvarma forbranningsluften. Samtidigt visas vid drift av forvarmare med lag temperatur pa den utgaende gasen benagenhet for korrosion av varmevaxlarens ytor och igensattning av kanalerna mellan dem, sarskilt vid roterande regenerativa forvarmare. The present invention relates to a heat exchanger plant comprising two heat exchangers, which are successively passed through by a gas stream, the temperature of which is to be regulated, a gas purification or similar gas treatment devices being inserted between the heat exchangers in the gas flow path, and which are also passed through. gases which, by emitting or absorbing heat, regulate the temperature of the former gas stream. The efficiency e.g. has electrostatic gas purifier depends on the treatment of the gases in the purifier takes place at comparatively high temperatures, so that the particles floating in the gas stream do not collect moisture and can be easily separated from the gas stream. In connection armed is required for effective action of a steam generator, e.g. in the case of a power plant, that the temperature of the final outgoing gases is reduced to a value which is practically possible by means of a heat exchanger device, consisting of air preheaters which preheat the combustion air. At the same time, when operating the preheater with a low temperature on the outgoing gas, it is prone to corrosion of the surfaces of the heat exchanger and clogging of the channels between them, especially with rotating regenerative preheaters.

Foreliggande uppfinning har darfor till avsikt att genom varmevaxlare reglera gastemperaturen i en gasbehandlingsanordning, som ej dr en del av varmeva.)daranlaggningen, vilket uppnas genom att gasbehandlingsanordningens hada andar anslutas till tva i serie kopplade varmevaxlare, varvid temperaturreglering utfores genom en forbiledning av en del av de reglerande gaserna. Samtidigt erhalles en fOrvarmning av de reglerande gaserna. Avsikten uppnas enligt uppfinningen i huvudsak darigenom, att en lampligen medelst ett spjall reglerbar ledning är anordnad irk] utloppssidan av den varmevaxlare, som ligger nedat i stromningsriktningen for de reglerande gaserna, till inloppssidan av den varmevaxlare, som Jigger uppat i samma gasers stromningsriktning. The present invention therefore has for its object to control the gas temperature in a gas treatment device which does not carry a part of the heat exchanger by means of heat exchangers, which is achieved by connecting the hot spirits of the gas treatment device to two heat exchangers connected in series, temperature control being performed by bypassing a part. of the regulatory gases. At the same time, a preheating of the regulating gases is obtained. The object is achieved according to the invention mainly in that a lamp which can be adjustably arranged by means of a damper is arranged in the outlet side of the heat exchanger which lies downwards in the flow direction of the regulating gases, to the inlet side of the heat exchanger which jigger upwards in the same gas flow direction.

Uppfinningen innefattar kylning av namnda gasstrom medelst tva varmevaxlare kopplade i serie efter varandra, varvid temperaturen av den i aggregatet inkominande gasen regleras medelst reglerbart inforande i detsamma av luft, som aterinfores i cirkulationen, sedan den lamnat aggregatet, samt genom reglering av varmeabsorptionen i den i strommens riktning sista varmevaxlaren medelst en justerbar forbiledning av luft kring denna varnievaxlare. The invention comprises cooling said gas stream by means of two heat exchangers connected in series one after the other, wherein the temperature of the gas entering the unit is regulated by means of controllable introduction into it of air, which is reintroduced into the circulation, after leaving the unit, and by regulating the heat absorption in the the direction of the current last heat exchanger by means of an adjustable bypass of air around this warning exchanger.

Foreliggande uppfinning omfattar aven ett aggregat, medfOrande ytterligare forbattring av forut omnaninda forhallanden genom placering av en elektrostatisk avskilj are mellan tva luftforvarmare, vilkas sammanlagda varmeoverfOringsyta är tillracklig for nedsattande av den utgaende gasens temperatur till varmegrader, som tidigare ansetts omojliga att uppna. For att beharska de erforderliga arbetsbetingelserna for temperaturen bade i avskiljaren och i luftfarvarmarna aterfOres en del av den starkast uppvarmda luften i cirkulationen for att stromma genom de seriekopplade forvarmarna, i och for uppratthallande av en bestamd temperatur i luftintaget mOjliggor en forbiledning kring den andra forvarmaren i luftstrommens riktning att en avsedd gasuttagstemperatur uppratthalles genom reglering av varmeupptagningen i den andra forvarmaren. The present invention also encompasses an assembly which results in further improvement of the foregoing conditions by placing an electrostatic separator between two air preheaters, the total heat transfer surface of which is sufficient to reduce the temperature of the outgoing gas to temperatures previously considered impossible to achieve. In order to master the required operating conditions for the temperature both in the separator and in the air heaters, some of the strongest heated air is returned to the circulation to flow through the series-connected preheaters, in order to maintain a certain temperature in the air intake it is possible to bypass the other. the direction of the air flow that a intended gas outlet temperature is maintained by regulating the heat absorption in the second preheater.

Uppfinningen kommer att forstas bast efter genomlasning av foljande detaljerade beskrivning av ett typiskt utforande av densamma i forming med bilagda ritning, dar den enda figuren utgor en schematisk framstallning av en anlaggning med luftforvarmare och dammuppsamlare enligt foreliggande uppfinning. The invention will be understood shortly after reading the following detailed description of a typical embodiment thereof in the form of the accompanying drawing, in which the single figure constitutes a schematic representation of a plant with air preheaters and dust collectors according to the present invention.

Med siffrorna 10 och 11 betecknas tvenne luftforvarmare som har Oro av roterande regenerativ typ och som aro kopplade i serie f8r stromning av gas och luft genom desamma, varvid luftintagsledningen betecknas med 12 och gasintagsledningen betecknas med 13. Genom en ledning 14 forbindes gasuttaget frail 2 184 677 anordning stegras den fran bi3rjan inkommande luftens temperatur fran I. ex. 7° C till 52° C, innan den inkommer i luftforvarmaren 10, sa: att korrosion ay. varmeoverfOringsytorna eller tilltappning av passagerna mellan dem vid forvarmarens 10 kalla ande nedbringas till ettuppratthallande ay' .den onskade slutliga gastemperaturen leder en for:. biledning 25 fran luftintaget 26 till den andra eller nedstroms forvarmaren 11 till en punkt pa luftuttagsledningen 21, som ãr belagen mellan fOrbindelsepunkten v returluftledningen 20 och7s-jalva uttaget tran forvarmaren 11. Ett spjall 28 i fOrbiledningen kan regleras medelst en rnotoranordning 29, som fungerar i enlighet med temperaturen i gasuttagsledningen 30. Luftatergangsledningen är ansluten till luftuttagsledningen 21 pa ena sidan av en skiljevagg 33 som stracker sig axiellt i denna ledning, under det att luftforbiledningen 25 ar ansluten till luftuttagsledningen 21 pa motsatt sida om skiljevaggen. Skiljevdggen stracker sig Iran en punkt i narheten av sj diva uttaget fran forvarmaren 11 till en punkt bortom anslutningen till luftreturledningen 20. Ph detta satt erhalles hogsta mojliga temperatur pa atercirkulationsluften, fast den utgaende luftens temperatur i delen 33B pa ledningen kan modereras av luft som farbiledes in genom ledningen 25, ndr motorn 29 fungerar enligt gasuttagstemperaturen i ledningen 30 for att Walla gasuttagstemperaturen approximativt vid eller natt och jamni Over det praktiska minimet. Numbers 10 and 11 denote two air preheaters which have rotating regenerative type concerns and which are connected in series for the flow of gas and air through them, the air intake line being denoted by 12 and the gas intake line denoted by 13. Through a line 14 the gas outlet frail 2 184 is connected 677 device, the temperature of the incoming air is increased from I. ex. 7 ° C to 52 ° C, before entering the air preheater 10, said: that corrosion ay. the heat transfer surfaces or the tapping of the passages between them at the cold spirit of the preheater 10 are reduced to a sustained ay '. the desired final gas temperature leads a for :. line 25 from the air inlet 26 to the second or downstream preheater 11 to a point on the air outlet line 21, which is located between the connection point of the return air line 20 and the outlet itself through the preheater 11. A damper 28 in the pre-line can be regulated by means of a rotor device 29, in accordance with the temperature in the gas outlet line 30. The air return line is connected to the air outlet line 21 on one side of a partition 33 extending axially in this line, while the air bypass 25 is connected to the air outlet line 21 on the opposite side of the partition. The partition wall extends to Iran a point near the sea outlet taken from the preheater 11 to a point beyond the connection to the air return line 20. In this way the highest possible temperature of the recirculation air is obtained, although the temperature of the outgoing air in part 33B of the line may be moderated by air passing in through line 25, when the engine 29 operates according to the gas outlet temperature in line 30 so that the Walla gas outlet temperature is approximately at or at night and equal to the practical minimum.

- Gastillstandet vid 150° C i ledningen 14 fir fordelaktigt Mr god verkan av dammuppsamlaren 15, da dammuppsamlarna darvid liitt kunna rengoras och Oxen arbeta med minsta mojliga praktiska kraftkostnad for elektrodernas laddning. Den ingaende luftens temperatur i ledningen 12 och den utgaende gasens temperatur i ledningen 30 kan hallas konstant vid alla belastningar med alla yttre ternperaturer. Den varma luften vid maximitemperatur for atercirkulation genom ledningen 20 uttages Iran luftfOrvarmarens uttag Iran den med skiljevagg forsedda ledningen 21, varigenom mangden av behovlig atereirkulerande luft Mlles vid ett minimum. Temperaturen av den gas som inkommer i den kalla forvarmaren 10 och dammuppsamlaren 14 kan hallas vid 150° C genom anvandning av fOrbiledningen 25 for kall luft kring den varma forvarmaren. Den varma forvarmarens temperatur Jigger betydligt Over daggpunkten, dd temperaturen vid dess intag alltid kommer att vara i narheten av 108° C, och den utgaende gastemperaturen approximativt 150°. Benagenheten for avsattningar och korrosion I den kalla forvarmaren 10 ar den minsta mojliga. Den fullstandiga regleringen av den utgaende gastemperaturen fran den kalla varmaren 10 och temperaturen av gasen genom dammuppsamlaren 15 samt regleringen den andra luftforvarmaren 11 med gasintaget till den forsta luftforvarmaren 10 och mellan dem dr insatt en elektiostatisk avskilj are, i sin helhet beteclinad med siffran 15. Med denna anordning joniseras damm och andra frammande partiklar som medforas av gasstrommen och utskiljas pa avsklljarens 15 uppsamlingsytor, fran vilka de borttagas medelst en kontinuerligt arbetande rensningsanordning, exempelvis bestaende av ett roterande luftmunstycke 16, Iran vilket en kraftig luftstrom riktas genom en, avskild del ay. hela samlingen elektroder,.-medan dammet- upp- - samlas i en tratt 17 som arbetar synkront rued munstycket 16. The gas condition at 150 ° C in the line 14 is advantageously very good for the dust collector 15, as the dust collectors can be easily cleaned and Taurus works with the least possible practical power cost for charging the electrodes. The temperature of the incoming air in line 12 and the temperature of the outgoing gas in line 30 can be kept constant at all loads with all external temperatures. The hot air at the maximum temperature for recirculation through line 20 is drawn from the air heater's outlet Iran to the partitioned line 21, whereby the amount of required recirculating air is measured at a minimum. The temperature of the gas entering the cold preheater 10 and the dust collector 14 can be maintained at 150 ° C by using the cold air bypass 25 around the hot preheater. The temperature of the hot preheater Jigger significantly above the dew point, dd the temperature at its intake will always be close to 108 ° C, and the outgoing gas temperature approximately 150 °. The susceptibility to deposits and corrosion in the cold preheater 10 is the smallest possible. The complete control of the outgoing gas temperature from the cold heater 10 and the temperature of the gas through the dust collector 15 and the control of the second air preheater 11 with the gas inlet to the first air preheater 10 and between them an electrostatic separator inserted, in its entirety denoted by the number 15. With this device, dust and other foreign particles carried by the gas stream are ionized and separated on the collecting surfaces of the separator 15, from which they are removed by means of a continuously operating cleaning device, for example consisting of a rotating air nozzle 16, Iran which a strong air stream is directed through a separate part ay . the whole collection of electrodes, .- while the dust- is collected in a funnel 17 which operates synchronously rued the nozzle 16.

Erfarenheten visar, att med vissa kolsorter som bransle kunna svarigheter mota: vid borttagande av flygaska frail trattar pa vanliga dammsamlare vid temperaturer under 115-127° C. Svarigheter mota ibland -vid en gastemperatur av 127° C och bli sarskilt betonade, nar den kommer till 115° C, vilket kan intraffa om -vintern och vid lag- belastning. Detta_ dr t. o: m. mera kritiskt vid en anlaggning i det fria. Genom denna erfarenhet har det blivit u.ppenbart, att _vid vanliga anordningar med forvarmare tillsamman med -5vriga dammavskiljare skulle kraftanlaggningen icke kunna arbeta med flagon storre varmeatervinning an motsvarande en. reduktion ay gastemperaturen till omkring 135° C efter forvarmaren. Kostnaderna for kol: och hoga belastningsfaktorer vid ett kraftaggregat sora det emellerticl onskvart att overv5ga stOr- resasom vid gastemperatu- rr i storleksordningen 120° C och 114° G yid uttaget fra'n fOrvarmarna, vilket skulle nedbringa temperaturerna till nagot liknande 115° C eller 107° C vid intaget till dammav-skiljarna med den vanliga anordningen. Experience shows that with certain types of coal as an industry, responsibilities can be met: when removing fly ash frail funnels on ordinary dust collectors at temperatures below 115-127 ° C. Responsibilities sometimes meet - at a gas temperature of 127 ° C and become especially stressed when it arrives to 115 ° C, which can occur in -winter and at team load. This_ dr t. O: m. More critical in an outdoor facility. From this experience it has become apparent that in the case of ordinary devices with preheaters together with other dust separators, the power plant would not be able to operate with a slightly larger heat output than the corresponding one. reduction of the gas temperature to about 135 ° C after the preheater. The cost of coal and the high load factors of a power unit meanwhile it is advisable to monitor large quantities such as gas temperatures of the order of 120 ° C and 114 ° G yid taken from the preheaters, which would reduce the temperatures to something like 115 ° C or 107 ° C at the inlet to the dust separators with the standard device.

Enlist fOreliggande uppfinning foreslas Overvinnande av dessa olagenheter genom anordnande av varmarna 10 och 11 i serie med dammuppsamlaren 15 mellan sig. Piled denna anordning kan gastemperaturen definitivt reduceras till 114°, vilket ar omolligt med hela ytan i forvarmarna placerad antingen framf6r eller efter dammavskiljarna. Varmeatervinningen i varmaren 11 fungerar perfekt fOr avgivande av gas med 150° C vid intaget till varmaren 10 for atervinningen med 114°. In accordance with the present invention, it is proposed that overcoming these problems be achieved by arranging the heaters 10 and 11 in series with the dust collector 15 therebetween. With this device, the gas temperature can definitely be reduced to 114 °, which is impossible with the entire surface of the preheaters located either before or after the dust separators. The heater recovery in the heater 11 works perfectly for delivering gas at 150 ° C at the inlet to the heater 10 for the recovery at 114 °.

For att kontinuerligt uppratthalla de onskade hoga temperaturerna for effektivt avskiljande av dammpartiklarna i den elektrostatiska avskiljaren 15 samt for att uppna den onskade kontrollen av lufttemperaturerna i forvarmarna 10 och 11, leder en atercirkulationsledning 20 fran luftuttagsledningen 21 fran den andra eller nedstroms anordnade luftforvarmaren 11 till intaget till flakten 23, dam luften blandas med yttre luft, som insu- ges genom ledningen 24, innan den passerar in i den forsta eller uppstroms luftforvarmaren 10 genom intagsIedningen 12. Med denna — —3 av den ingaende lufttemperaturen i den kalla forvarmaren 10 framgar av praktiska pray vid drift av stora aggregat vid olika belastningar och yttertemperaturer, vilka utomhusanlaggningar aro underkastade. In order to continuously maintain the desired high temperatures for efficient separation of the dust particles in the electrostatic separator 15 and to achieve the desired control of the air temperatures in the preheaters 10 and 11, a recirculation line 20 from the air outlet line 21 from the second or downstream air preheater to the flue 23, when the air is mixed with external air, which is sucked in through the line 24, before it passes into the first or upstream air preheater 10 through the intake line 12. With this - -3 of the incoming air temperature in the cold preheater 10 is practical pray when operating large units at different loads and outside temperatures, which outdoor systems are subject to.

Claims

Patent claim:

A heat exchanger system, comprising two heat exchangers, which are successively passed through by a gas stream, the temperature of which is to be regulated, a gas purification or similar gas treatment device being inserted between the heat exchangers in the gas flow path, and which are also flowed through by gases which by emitting or absorbing heat regulating the temperature of the former gas stream, Urine - drawn from the fact that a conduit (20) which can be regulated by means of a damper (35) is arranged from the outlet side of the heat exchanger (11), which lies downwards in the flow direction of the latter the gases, to the inlet side of the heat exchanger (10), which is located upwards in the flow direction of the same gases.

Plant according to claim 1, characterized in that a lamp (25) which can also be adjusted by means of a damper (28) is arranged in the circuit for the regulating gas between the inlet and outlet stalls to the heat exchanger (11) lying down in the flow direction.

3. Plant according to claim 1 or 2, characterized in that in the direction of the heat exchanger (11) of the heat exchanger (11) located in the direction of flow of the regulating gases, a separating wall (33) arranged in its longitudinal direction is arranged, so that it both sides are surrounded by heated gas, and that the first-mentioned adjustable line (20) is connected to the outlet line (21) on one side of the partition (33).

Plant according to patent claims 2 and 3, characterized in that the bypass (25) is connected to the outlet line (21) on the other side of the partition (33).

Plant according to claim 1 or the following, characterized in that a temperature-sensing means (34), which is controlled by the temperature of the regulating gases, when they flow into the heat exchanger (10) located in their direction of flow, acts on the damper ( In the first-mentioned controllable line (20).

Plant according to claim 2 or the following, characterized in that a thermally sensitive means (29), which is controlled by the temperature of the gas stream exiting the heat exchanger (10) located at the bottom in the direction of flow of the regulated gases, acts on the damper (28). ) in the preface (25).

Plant according to claim 1 or the following, characterized in that the gas treatment device (15) is constituted by a dust particle separator plant, which is formed by a number of chambers, part of which performs the separation of dust particles from the hot gas stream, while the other part (16 , 17) by blowing through air is subjected to a cleaning from the separated dust particles.

Plant according to claim 7, characterized in that the gas treatment device is constituted by an electrostatic dust separator (15), which operates efficiently with a temperature range which lies between the inflow temperature of the regulating gas in the heat exchanger plant and its outflow temperature therefrom. Request publications: Patent patent ter from Sweden 131 027; France 1,065,660; USA 2 363 870, 2 570 85

9. Stockholm 1962. Eungl. Boktr. P. A. Norstedt & SiMer. 620089