CA2003828C - Incineration control apparatus for a fluidized bed boiler - Google Patents

Incineration control apparatus for a fluidized bed boiler

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Publication number
CA2003828C
CA2003828C CA 2003828 CA2003828A CA2003828C CA 2003828 C CA2003828 C CA 2003828C CA 2003828 CA2003828 CA 2003828 CA 2003828 A CA2003828 A CA 2003828A CA 2003828 C CA2003828 C CA 2003828C
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Canada
Prior art keywords
heat recovery
incineration
combustibles
chamber
temperature
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CA 2003828
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French (fr)
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CA2003828A1 (en
Inventor
Shigeru Kosugi
Takahiro Ohshita
Tsutomu Higo
Naoki Inumaru
Hajime Kawaguchi
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Ebara Corp
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Ebara Corp
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  • Fluidized-Bed Combustion And Resonant Combustion (AREA)
  • Incineration Of Waste (AREA)

Abstract

A control circuit (B) is adapted the steam pressure at a boiler drum (17) which receives heat from a incineration chamber (3) in a fluidized bed type boiler (A, C) to be correlated to the thermal energy to be recovered and transferred to the boiler drum and to improve a responsiveness for the suppressed control of increase or decrease of the steam pressure caused by variation of a steam load. The velocity of heat recovery is controlled in accordance with the steam pressure in the boiler drum (17) which is detected by a pressure gauge (20b) and a combustibles supply unit (12, 13, 14) for supplying combustibles to the boilers (A, C) is also controlled accordingly.

Description

AN INCINERATION CONTROL APF'ARATUS ~O~
A FLU:tDIZED BE~ BO:~L.ER
TECHNICAL FIEL.D:
The present inventlon relates to a control apparatus capable o-f controlling the amount of therma:L energy recov-ered -from a sector of the fluidized bed o-f a boiler system and supplied to the boller drum thereof, the boiler system being so constructed that such combustibLe.s as municipal refuse, industrial waste, coal or the like are lncinerated in a so-called -fluidized bed and the boiler drwll receives the resulting therma:l energy. The present invention relates more particularly to the improvement of an :Lncinerat:lon control apparatus adapted to enhance the response of the suppressed control o-f :Lncreases and decreases :Ln steam pressure caused by variations in the steam load by corre-lating the steam pressure in the boiler drum with control of the thermal energy recovered by the boiler drum.
BACKGROUND ART:
Fluidized bed boilers are widely known. However, there has been general concern recently about boilers o-f this type which have a construction wherein the fluidizing medium is divided into two parts, one part being accommo-dated in the inclneration chamber and -the other being accom-modated in the thermal energy recovery chamber in such a manner that the medium is circulated, thermal energy being recovered -from the heat recovery means which takes the form of water pipes or the like provided in the recovery chamber, the amount of recovered thermal energy being controllable.
As for the principle o-f controlling the amount o-f thermal energy to be recovered -from the fluidizing medium in such a heat recovery chamber, there are known methods where-in the contact area between the heat recovery means such as water pipes or the like and the -fluidizing medium in the fluidized bed in the heat recovery chamber is so varied that the amount o~ thermal energy trans-ferred may be controlled (i.e., the so-called slumping bed method), or wherein the condition o-f the bed comprised of the -fluidizing medium in the heat recovery chamber is so varied that the heat trans-fer coe-fficient between the -fluidizing medium and the heat 3~

recovery means may be controlled. The la-tter cate~ory includes such methods as that wherein -the condition of the bed comprised o-f the -fluidizing medium is varied between a -fluidized bed condition having an ex-tremely high heat transfer coe-fficient and a -fixed bed condition having an ex-tremely low heat trans-fer coef-ficient, heat recovery being intermittently controlled (as disclosed in Japanese Patent Public Disclosure No. 58-1~3937, U.S. Pa-tent No. 3,970,011 and US Paten-t No. 4,363,292), and that whereln the bowndary between the area of the -fluidized bed condition and the -fixed bed condition :Ls continuously varied so that heat recovery may be controlled continuously and smoothly (as disclosed :Ln Japanese Paten-t Public Disclosure No. 59 :l990).
Additlonally another method has recently been proposed by the inventor o-f the present :Lnvention (as disclosed in Japanese Patent ~ppllcation No. 62-9057) in which the fluid-izing medium :Ln the heat recovery chamber is supplied with air at a relatively low a:Lr velocity (or 0 Gmf - 2 Gm-f in respect of mass velocity), the ~luidizing medium is main-tained as a transient bed which is a typical bed conditionwith a heat trans-fer coe-fficient which will vary subs-tan-tially linearly in relation to the air veloci-ty, -the heat trans-fer coe-f~icient therein being continuously varied in a substantially linear manner so that recovery of thermal energy may be controlled continuously and smoothly.
Regarding the condition of the bed, it must be added that although in the scienti-fic de-finition the bed in which the air velocity is 0 Gmf - 1 Gm-f is a -fixed bed and the bed in which the air velocity is higher than 1 Gmf is a fluidized bed, it is commonly known that an air velocity higher than 2 Gm~ is required to form a stable fluidized bed. Further, the term "moving bed" used herein is to be understood to mean a bed in which a fluidizing medium is constantly descending and moving, and this satisfactory descending condition formed in it is not destroyed by bubbling up to about 1.5 Gm-~ - 2.0 Gmf.
It should be pointed out here that slnce controlling the amount O-r thermal energy recovered by a boiler drum -from ~0~ 32~3 a heat recovery chamber is particu:Larly effective ln maln--taining the temperature of! the flu:Ldized bed in the incln-eration chamber within an appropriate range. this type o-f control is regarded as bene-fi.cial because it o-f-fers the -following advantages.
(l) ~y keeping the temperature o-f a -fluid:ized bed at 800~C to 850~C, incineration e-~'-fic:Lency may be improved (in -the case of coal burning).
(2) By avoiding any increase in the tempera-ture o-P the fluidized bed above 850~C, burning o-f the :fluidized bed may be prevented (in the case o-f incinerat:Lon o-f the municipal re-fuse).
(3) By keeping the temperature o-f -the -fl.uidized bed at 800~C - 850~C, which is a desirable level -for drom:Lte, lime stone and the like to absorb sul-f'ur in the case o-f coal burning, desulfurization may be e-f-fectively achieved.
(4) By avoiding any decrease in the temperature o-f the -fluidized bed below 700~C, generation o-~ carbon monoxide may be prevented (in the case o-f coal burning).
(5) Corrosion o~ heat recovery means such as water pipes and the like can be prevented.
An example o-f such an apparatus -for controlling the amount o-f thermal energy recovered -from a heat recovery chamber which allows the advantages explained above to be enjoyed is disclosed in US Patent No. 4,363,292 granted to Engstrom et al. More speci-fically, according to this appa-ratus as shown in Fig. l, the amount o-f heat recovery ~rom a pipe lO~ as a heat recovery means in a second -fluidizing zone lO0 will be controlled mainly depending on the tempera-ture in a -furnace, mainly the temperature of a fluidized bed in a -first fluidizing zone 107, with regurating the amount ; o-f heat recovery air supplied -from second boxes, through ori-fices 102 to the second -fluidizing zone lO0 constituting with the fluidizing medium as a heat recovery in a heat recovery chamber, by opening or closing a control valve 104 provide at a conduit 103 in communication with the second box lOl in accordance with a temperature control device TC

~0 al3~

respons:Lve to the temperature signal from a temperature sensor 105 Ln the ~urnaces.
However, with a prior art fluidized bed type boiler o-f the type explained above, it has been di-Lficult to readily suppress any increase or decrease in the steam pressure in the boiler drum caused by variations in the steam load.
More speci-fically, with a -fluidized bed bo:Ller o-f this type, it is normal practice to control the amount of combustibles supplied to the fluidized bed in the incineration chamber (or the fluidized bed in the -first -fluidizing zone 107, ~or example) by detecting any variation in the steam pressur-e so as to restrict any inf'luence due to increases in the steam pressure in a bo:Ller drum. This practice is al.ready well known. However, even i~ the amount O-e combustibles suppl:Led is increased upon detecting a reduct:Lon in the steam pressure, the thermal inertia o-f the fluidized bed in the incineration chamber is extremely high and hence the temperature of the fluidized bed will not increase abruptly, but only gradually.
Accordingly, if the volume o-f air supplied -for heat recovery to the -fluidi~ing medium in the heat recovery chamber is controlled and the air supply is increased solely in dependence upon the gradual increases in temperature o~
the -fluidized bed which occur in the manner explained above, the amount of thermal energy to be recovered from the fluid-izing medium in the heat recovery chamber (or the jet stream bed in the second ~luidizing zone, -for example) cannot be rapidly augmented. Thus any increase or decrease in the steam pressure in the boiler drum caused by variations in the steam load cannot be quickly restrlcted, the severity o-f this phenomenon depending on the amount of recovered heat which is to be circulated back to the boiler drum.
DISCLOSURE OF THE INV~NTlON:
It is there-fore a general object of the present invention to solve the problems inherent to the above-mentioned prior arts in which quick responses in the control 20(~38~

o-f varlat:Lons ln steam pressure necess:Ltated by varlatlons i.n steam load have not been possible.
Ano-ther obJect of the present inven-tion i9 to provide an lncineratlon contro:L apparatus for a fluidlzed bed type boiler capable o-f quickly controlling increases or decreases in the steam pressure in a boiler drum caused by variations in steam load by controlling the amount of thermal energy recovered by the boiler drum :Ln response to any variation in steam pressure which immediately responds to varlations in the steam load.
It is a f-urther object of the present invention to provide an inclneration control apparatus -for a -L'luidized bed -type boi~er which exhibits a substant:Lally enhanced response to steam pressure controlling operations at the time o-f varlations in the steam load by an arrangemerlt in which the operation o-f controll.lrlg the amount of combusti-bles being supplied in accordance with the steam pressure :Ls correlated ~ith the operation of controlling the amount o-f thermal energy recovered -from the heat recovery chamber in accordance with the temperature in the incineration chamber.
It is a still -further object o-f the present invention to provide an incineration control apparatus for a -fluidized bed type boiler which will not inhibit response in the operation o-f controlling increases and decreases in the steam pressure due to external disturbance at the time o-f a normal increase or decrease in steam load, irrespective o~ whekher the steam load is increasing or decreasing.
Yet another obJect of the present invention is to provide an incineration control apparatus for a fluidized bed type boiler which will not inhibit response in the operation of controlling decreases in the steam pressure due to external disturbance whether the steam load is increasing without causing a situation wherein insuf-ficient thermal energy is recovered by the boiler drum frorn the heat recovery chamber even when the normal steam load is e~cessive.
According to the first embodiment o-f the presen-t invention, there is provided a means of control]ing air 3~

supply -for heat recovery in accordance with the prevailing steam pressuLe which is adap-ted to control the a~oun-t of thermal energy recovered by a boiler drum *rom a heat recovery chamber in accordance with the prevailing steam pressure by varying the amount of air supplied to the heat recovery chamber in accordance ~ith the steam pressure resulting therefrom. More speci~ically, -the arrangement in a typical embodiment is such that the operat:Lon of the rneans -for contro:Lling the amount o~ combustibles supplLed which i~s adapted to control the amount o-f the combustibles supplied to the incineration chamber in accordance w:Lth -the steam pressure :Ln the boiler drum is correla-ted with the operation o-~ the means -for controlling air supply for heat recovery which is adapted to control the amount of thermal energy recovered by the boiler drum from the heat recovery chamber by varying the amount o-f air supplied to the heat recoverY
chamber in accordance with the temperature in the incinera-tion chamber, and a set temperature value control means i9 provided which is adapted to control in accordance with the prevailing steam pressure in the boiler drum the set temper-ature required in a -fluidized bed in the incineration chamber on the basis of the control of the air supply -for heat recovery. This arrangement provides an incineration control apparatus for a fluidized bed type boiler which is capable of solving the above-mentioned problems and respond-ing immediately to variations in steam pressure so as to instantly change the amount o~ thermal energy recovered by the boiler drum from the heat recovery chamber, thereby providing quick control of variations in the steam pressure.
According to the present invention as explained above, since a control means adapted to control ~he amount of thermal energy recovered by the boiler drum from the heat recovery chamber in accordance with the steam temperature is additionally provided, the amount of thermal energy recov-ered by the boiler drum can be controlled on the basis of variations iIl steam pressure which will immediately respond to variations in the steam load instead o-f on the basis of such -~actors as the temperature in -the incineration chamber 20~)~8~3 wh:Lch rnay only change gradual:l,y due to -I;hermal i,nertia.
This prov:ides the great benefit o:~ allowing increases or decreases in the steam pressure in the boiler drurn caused by variat:Lons in the steam load to be quickly controlled.
The control means for controlling -the amount of thermal energy recovered ln accordance with the prevaillng steam pressure includes a means for detecting steam pressure adapted to output a steam pres~:ure signa~ lndicating the steam pressure and a temperature detecting means adapted to detect the prevailing temperature in the incineration chamber and output temperature signals indicating the detected temperature. Thus, the amount of combustibles supplied is controlled in response -to the temperatllre signals while the velocity o-f the air supply -for heat recovery w:Lll be so controlled that the -temperature in the incineration chamber may be kept identical to -the speci-eied set temperature. The set temperature control means is adapted to correlate the operational output signals from the pressure controller which serves as the means for control-~0 ling the amount of combustibles to be supplied with the setvalue signals from the temperature controller which serves as the means ~or controlling the air supply for heat recov-ery. This allows the operation Or controlling the amount o-f combustibles supplied to the incineration chamber in accordance with the steam pressure in the boiler drum to be correlated with the operation of controlling the amount of air supplied -for heat recovery 'by the boiler drum -from the heat recovery chamber by varying the air supply to the heat recovery chamber in accordance with the temperature in the incineration chamber. Thus the amount o* air supplied to the heat recovery chamber for heat recovery purposes may be increased or decreased rather rapidly even when ~he control operation undertaken by the means for controllinF the amount o-f combustibles supplied is relatively long in duration, and this ensures that the response o-f the operation of control-ling the steam pressure a-t the time of variations in the steam load will be improved to a substantial degree.

Z0038~E3 According to the second embod:lMent o-L the present invention, a means -ror controlling the amount o-~ combusti-bles supplied in accordance with the prevailing steam load is provided in addition to the various means employed :in the -first embodiment, the control means being adapted to operate and generate appropriate operatiorlal output signals which serve to continuously adJust the amount o-f combus-tibles supp]ied in correspondence with normal increases and decreases in the steam load which depend on -the steam -f:Low rate prevailing during the supply o-~ operatiolla] output signals when the pressure controller wh:Lch controls the amount o-f combustibles supplied is in a ~alanced state.
Thus -the pressure controller wh:Lch serves as the means -for controlling the amount Oe combustibles supplied is balanced when in the normal condition so that the operational output signal is kep-t at a value o-f 50% and -the amount o-f air supplied (air velocity) for heat recovery by the means for controlling supply for heat recovery in response to the operational output signals is held around a median value o-f 50~~. In this way the range o:~ variation in the air supply or the thermal energy capable o-f being recovered by the boiler drum -from the heat recovery chamber may be maximi.zed whether an increase or a decrease in the steam load is taking place, and the response of the operation -for control-ling increases and decreases in the steam pressure due toexternal disturbances will not be inhibited at all, irre-spectlve of whether there is an lncrease or a decrease in the steam load.
According to the third embodiment o~ -the present invention, a means o-f controlling air supply -for incinera-tion is provided in addition to -the various means employed in the second embodiment, the means -for controlling air supply for incineration being adapted to receive from the means for controlling the amount of combustibles to be supplied in accordance with the steam load operational output signals which increase continuously in correspondence with any increase in steam load and increase the amount of air supplied (or air velocity) for incineration to the X(~3~

incinerat:Lon chamber. Thus -the amount o~ P]uldizing rnedium circulated in the heat recovery chamber will be increased when the steam load increases normally and a sufficient amount of thermal energy may be sa-fely recovered by increas-klg the amount o-f regenerative thermal energy. Hence there will never be a short-fall o-f thermal energy recovered by the boiler drum -from the heat recovery chamber and the response o-f the operation of controlling decreases in steam pressure due to external disturbances, which involves increasing the steam load, will not be impaired at a:L:L. This is a signi*i-cant improvement over the prior art.
BRIEF EXPI,ANATION OF DRAWINGS:
Flg. 1 is a schematic view :Ll:Lustrat:Lng the cons-trLIc-tion Oe a -fluidized bed type boiler according to a pr:Lor art;
Figs. 2A, 2B, 3A, 3B and 4 are explanatory illustra-tions showing the constitution and operation of the boiler to be controlled by the incineration control apparatus according to the present invention, wherein F'igs. 2A and 2B
are vertical sectional views showing -the constitution o-E the boiler; Fig. 3A is a graph showing by way o-f example the relationship between the air velocity (shown by the abscissa) of the air for incineration and the amount of fluidizing medium circulating (shown by the ordinate); Fig. 3B is a graph showing by way o-f example the relationship between the air velocity (shown by the abscissa) o-f the air for heat recovery and the amount of -fluidizing medium circulating (shown by the ordinate); and Fig. 4 is a graph showing by way o-f example the relationship between the air velocity (shown by the abscissa) of the air -for heat recovery and the heat transfer coe-fficient ~ (shown by the ordinate) of the heat recovery tube in the moving bed:
Figs. 5A, 5B and 6 show a -first embodiment of the incineration control apparatus according to the present invention, wherein Figs. 5A and SB are block diagrams respectively showing the constitution o-f the embodiment;
and Fig. 6 is a graph showing by way of example the in~ut and output characteristics o~ the signal inverter 32 which 8~3 -:1.0-serves as the means ~or controlL:Lng the set -temperature values;
~ igs. 7A, 7B, 8 and ~ show a second embodiment o-~the incineration control apparatus according to the present invention, wherein Figs. 7A and 7B are block diagrams respectively showing the constitution o~ the embodiment;
Fig. 8 is a graph illustrat:Lng by way o-~ example the input and output characteris-tics of the computing element 35 wh:Lch serves as the means for controlling the amount o-~ combusti-bles supplied in accordance with the steam load; and Fig. gis a graph showing by way Or example the relationsh:Lp between the steam flow rate (shown by the ordinate) :Ln the condition wherein the means 31 ~or controlllng the amourlt Oe combustibles to be supplied is in a balanced state and the amount of combustibles requ:Lred for generating that steam -flow rate, or the operational output signals YO (shown by the abscissa) -from the computing element 35; and Figs. 10A and 10B are block diagrams showing a third embodiment o-f the incineration control apparatus according to the present invention.
BEST ~ODE OF CARRYING OUT THE INVENTION:
F:igs. 2A and 2B illustrate di-f~erent examples o-f boilers which are to be controlled by the :Lncineration control apparatus according to the present invention. In Fig. 2A, the entire boiler A is enclosed by the wall 1 and the incineration chamber 3 is defined by a pair o~ partition plates 2, 2, while the heat recovery chambers 4, 4 are de-fined between the partition plates 2, 2 and the wall o~
the boiler, respectively.
At the bottom portion o-f the incineration chamber 3 is an air chamber 6 the upper sur-~ace o-f which is covered by an air supply plate 5 having a multiplicity o-f air supply ports 5a. The air chamber 6 may be separated into a plural-ity o-f sub-chambers. The air chamber 6 is connected to an incineration air supply tube 7 coming -from the incineration air source. A temperature sensor 3a which serves as a means ~or detecting temperature is supported at a position above the air chamber 6. The air supply plate 5, air supply ports ~0 5a and air chamber 6 together const:Ltute the means for supplying air for inclnerat:Lon. Ins:Lde the incineration air supply tube 7 are inserted a control valve 7a and a -f]ow meter 7b with the former c:Loser to the source of air -for incineration. In the bottom par-t o-f the heat recovery chamber 4 is an air chamber 6a the upper sur-face of which is covered by an air dispersion plate 8 (means Oe a:Lr swpply for heat recovery) having a multiplicity of air supply ports ~a and to which is connected a heat recovery air supply tube 9 -from the source o-f a:ir for heat recovery. In the heat recovery air supply tube are inserted a control valve 9a and a flow meter 9b with the former closer to the sowrce o-f air -eor heat recovery. ~ heat recovery tube 10 is SPirallD
arranged above the air dispersion plate 8 in the heat recovery chamber 4. One end O-e the heat recovery tube 10 is directly connected to a boiler drum 17, -to be explained later, and the other end o-f the tube lO is connected to the boiler drum through a circulation pump 11.
The incineration chamber 3 and heat recovery chamber 4 are both filled with particles (having a particle size o-f approx. 1 mm) o-f quartz or the like. It is to be noted that the particles contained in the incineration chamber 3 are permitted to flow over the upper end o-f the respective partition plates 2 into the fluidizing medium contained in the heat recovery chamber 4, while the particles con-tained in the heat recovery chamber 4 are caused to re-turn to the incineration chamber 3 through the area below the respective partition plates 2, thus allowing circulation o-f the -fluid~
izing medium.
Disposed at an opening (not shown) -that communicates with the incineration chamber 3 is a means 14 -for supplying combustible~, which is equipped with a screw type -feeder 13 (see Fig. 5A) that is driven by a mo-tor 12 incorporated therein.
~n the other hand, the boiler drum 17 is arranged to -fit in the wall 1 of the boiler A at the upper portion thereof in such a manner as to be surrounded by a heat receiving water pipe 16 having a -flue opening 16a at one 2~)~38~

por~ion thereof and capab:Le of rece:Lv:Lng heat ~rom the :Lnc:Lneratlon chamber 3. The bo:Ller drum 17 Is provlded wi-th an upper steam drum 17a and a lower water drum 17c which is connected to the steam drllm by rneans of a multip:llcity of convective -tubes 17b.
A water supply pipe 19 extends -from the water source to the steam drum 17a and the steam pipe 20 extends -from the steam drum 17a to a steam load 21 through a stea1n separator 17d. There are provided in the steam pipe are a flow meter 20a which serves as a means -for detectlng steam flow rate and a pressure gauge 20b which serves as a means for detecting steam pressure. Reference numeral 22 des:lgnates an exhaust port for combustion gas embedded in the wal:L 1 o-f the boi].er adJacent to the boiler drum 17.
The control apparatus B is provided as a separate unit adJacent to the boiler A which :Ls controlled by the apparatus B. The apparatus B is received over the signal lines the output signals respectively -from the temperature sensor 3a, the :flow meters 7b, 9b and 20a as well as the pressure gauge 20b. The output signals -from the control apparatus B are supplied in turn over the signal lines to the control valves 7a, 9a and a combustibles supplying means 14, respectively.
Fig. 2B illustrates an alternative constitut:ion of a boiler to be controlled by the incineration control appara-tus according to the present invention. In Fig. 2B, the entire boiler C is enclosed by the wall 1. The incineration chamber 3 is defined by a pair o-f re-flection partition plates 2b, 2b with the upper end port:Lon 2a ben-t upwardly and vertically at the central portion o-f the bottom of the boiler below the inclined surface o-f the partition plates whi]e the heat recovery chambers 4, 4 are defined at -the outer periphery of the central bottom portion above the inclined surface.
At the bottom of the incineration chamber 3 are provided air chambers which are divided into a plurality of sub-chambers the upper sur-face of which is covered by an air supply plate 5 having a multiplicity o-f air supply ports 5a ;~0~3~

and arranged as a ramp lead:lng toward the center o-f the bottom portion of the incineration chamber. The air chamber 6 is connected to the incineration air tube 7 -Prom the source of air -~or incineration. The temperature sensor 3a which serves as the means Por detecting terrlperature is supported above the chamber. The air supply plate 5, air supply ports 5a and air chamber 6 toge-ther constitute the incineration air supply means. Inside the incineration alr tube 7 are inserted in series a control v~lve 7a and a -flow meter 7b with the former closer to the air- inclnera-tion source. On the other hand, mu:ltiple rows oP cylindrical air dispersion -tubes 8b are provided extending along the inclined upper surface of the reflection partition plate 2b as the heat recovery air supply means (:Ln Fig. 2B, only one row of such tubes are shown). ~ multiplicity Oe air disper-sion port:Lons 8a' are drilled :Ln the surface of the air dispersion tube 8b on the side facing the reflection parti-tion plate 2b. The lower end of the air dispersion tube 8b is connected to the heat recovery air supply tube 9 which extends from the heat recovery air supply source. A control valve 9a and the flow meter 7b are inserted inside the air supply tube 9 in series with the former closer to the heat recovery air supply source. A heat recovery tube 1~ which is incorporated in the heat recovery means is arranged above the air dispersion tube 8b in the heat recovery chamber 4.
One end of the heat recovery tube 10 is connected directly to the boiler drum 17 and the other end is connected to the ; boiler drum via the circulation purnp 11.
The incineration chamber 3 and the heat recovery chamber 4 are both filled with a fluidizing medium such as particles of quartz (havin~ a particle size of about 1 mm) or the like. The fluidizing medium in the incineration chamber 3 is allowed to enter the heat recovery chamber 4 over the upper end portion of the respective reflection partition plates 2b while the fluidizing medium in the heat recovery chamber 4 returns to the incineration chamber 3 below the respective reflection partition plates 2b in the 2(~11 g[)3 ~r 1~ ~3 heat recovery chamber 4, the fluidi~ing medium thus belng capable of circuLating in both chambers.
A means 14 ~or supplylng combustibles are provided at the opening (not shown) provided in communication with the incineration chamber 3. A screw-type f'eeder 13 (see Fig. 5A) driven by a motor 12 is incorporated in this com'bustible supply means.
The boiler drum 17 ~its in the wall 1 o-f the boiler C
at the upper portion thereof in such a manner as to be surrounded by a heat receiving water pipe 16 having a -elue opening 16a at one portion thereo-f' and capable Oe receiving heat -from the inc:Lneratlon charnber 3. The bo:Ller drum 17 ls provided with an upper s-team drum 17a and a lower water drum 17c which are connected by means of a multiplicity of convective tubes 17b.
A water supply pipe 19 is provided extending erom the water source to the steam drwn 17a. Provided in a s-team pipe 20 extending Prom the steam drum 17a -to a s-team load 21 via a steam separator 17d are a -flow meter 20a serv:Lng as a means for detecting steam flow rate and a pressure gauge 20b serving as a means -for detecting steam pressure. Re-ference numeral 22 designates an exhaust port for combustion gas embedded in the wall 1 of the boiler adjacent to the boiler drum 17.
~ control apparatus B is provided as a separate uni-t adjacent to the boiler C which it controls in accordance with the present invention. The control apparat-us B is supplied with output signals which pass through signal lines from the temperature sensor 3a, the flow meters 7b, gb and 20 and the pressure gauge 20b. Output signals -from the control apparatus B are supplied through signal lines to the control valves 7a, 9a and the combustion supply means 14.
A general explanation o-f -the operation o-f the boilers A and C shown in Figs. 2A and 2B and controlled by the incineration control apparatus according to the present invention will now be given.
The fluidizing medium in the incineration chamber 3 is blown upwardly by incineration air having an adequate air --'' Z00313~3 velocity (a mass veloc:Lty o-f more than about 2 Gmf') which ls supplieA into the air chamber 6 through the incineratlon air pipe 7 and in,3ected upwardly ln the lncineratlon chamber 3 Prom the alr supply ports 5a of the alr supply plate 6, thus formlng a -~luldized layer to become a fluld bed.
A part Or the -fluld bed ln the inclneratlon chamber 3 is caused to flow -from the splashing surface of -the -fluid bed and a portion of the -fluid:Lzing medium which Jumps over the upper end portion 2a of the part:Ltion plate 2 is caused to swirl into the heat recovery chamber 4. The same quan-tity o-f -fluidizlng mediu~n, i.e. corresponding to -the amount o-f'-fluidizing medium thus entering the heat recovery chamber 4, is caused to return to the incineration chamber 3, there-by creating a circulating flow. The quantity o-f fluidizing medium which may flow into the hea-t recovery chamber 4 -from the incineration chamber 3 can be controlled in accordance with the air veloc:ity of the incineration air (or the mass velocity).
Fig. 3A illustrates an example of the relationship between the air velocity of the incineration air (the mass velocity) and the amount o~ fluidlzing medlum which -flows lnto the heat recovery chamber from the lnclneration chamber. According to this graph shown ln Fig. ~, when the alr veloclty varies ln the range of from 4 ~m-f' to 8 Gm-f, the amount o-f circulating fluidizing medlum may be controlled to not exceed a value o-~ ten times in the approximate range o-f from ~.l to 1.
Fig. 3B illustrates an example o-f the relationship between the air velocity of the heat recovery air (or the mass velocity) and the descending speed of the fluidizing medium in the moving bed in the heat recovery chamber 4, or the amount of fluidizing medium which may be returned to the incineration chamber 3 from the heat recovery chamber 4.
According to -this relationship. the amount of circulating fluidizing medium which is determlned -from the amount o-f fluidizing medium to be returned to the incineration chamber may be expressed by the relationship (or operational curve) wlth the amount of fluldlzing medlum whlch -flows into the 2C)~)3~

heat recovery charnber (or the parallleter shown in ~ig. 3B).
The extent of circulat:Lon varies depend:Lng on the combust,ion air velocity and Lncreases linearly ~or each amount of flu:Ldizing medium that overflows :from the incineration chamber to the heat recovery chamber. I-f the a~lount -for the circulation of f'luidizing medium -~lowlng -from the incinera-tion chamber is speci-fied, this amount o-f -~luidizin~ medium may increase or decrease substantially proportionally to the air velocity for heat recovery expresscd by the ~bsclssa along the corresponding operational curve in the rarlge o~
0 to 1 G~f o-f the air velocity -for incineration.
Accordingly when the air velocity of the lncineration air is constant, the amount Oe circula-ting fluldizlng med:Lwn may be controlled in accordance with the a:Lr veloc:Lty of the air for heat recovery. When the a:Lr velvcity o-f the incin-eration air Ls not cons-tant, ~lowever, the amount of circu-la-ting -fluldizing medium may be controlled in accor-dance with the air velocity o-~ both the air for heat recovery and the air -~or incineration.
CombLIstibles such as coal or the like, or waste such as municipa:L re-fuse or the like are charged onto the fluid bed in the :Lncineration chamber 3 for incineration there and keep the -fluid bed at a high temperature in the order of 800~C - 900~C. As a result, the boiler drum 17 receives the heat generated by thls high temperature and converts the water supplied to the boiler drum 17 via the water supply pipe 19 into steam in the steam drum 17a. Then, after water has been removed by the steam water separator 17d, -the steam will be supplied to the steam load 21 via the steam pipe 20.
The operation of boiler of the type explained above is well known in itself.
On the other hand, the ~luidizing medium in the heat recovery chamber 4 will -form a moving bed which gradually descends in an orderly fashion in the downward direction as a solid substance in response to injection of the air for heat recovery, the air velocity of' which is relatively slow -~rom the dispersion ports 8a of the air dispersion plate 8 in the heat recovery chamber. This moving bed will remain ZC)(~313~

:Ln contact w:Lth the heat recovery tube 10 SUC}I as to direct the heat in the moving bed into -the water :Ln the heat recov-ery tube 10 by means of heat transrer. Conseqllently, the heated water in the heat recovery tube 10 will be ~orced into the steam drum 17a by me~ns o-P the circulation pu~p 11.
In this way. the heat in the -f~Luidi~ing medium in the heat recovery chamber 4 or the heat in the fluid bed in the incineration chamber 3 will be recovered by and transferred to the boiler drum 17. In this way, the heat in the -rluid-i~in~ med:lum contained in the heat recovery chamber ~ andthe heat in the fluid bed in the lnclnerat:lon chamber 3 wll]
be trans-eerred to the boller drum. However, :Lt is to be noted that the amount of thermal energy recovered may be controlled in accordance wlth -the a:lr velocity (or the mass velocity) of the air for heat recovery which is in-to the heat recovery chamber 4 through -the air dispersion plate 8.
More specifically, Fig. 4 illustrates in solid lines an example Oe the relationship between the velocity (or the mass velocity) of the heat recovery air and the heat trans-fer coe-fficient ~ o~ the heat recovery tube 10 in the moving bed. According to this graph, when the air velocity o-~ the heat recovery air is varied in the range -~rom 0 Gm-~ to 2 Gm~, the heat transfer coefficient ~ may be controlled substan-tially linearly with a relatively large gradient (or gain) compared to that o~ the fluidized bed or the fixed bed.
In the same graph, the dotted line indicates exa~ples o~ the heat trans-~er coe-fficient which will vary depending on the air velocity, the indicated heat trans-fer coe-fficients bein~ those which would normally be a-ttained in a -~ixed bed at an air velocity of less than 1 Gmf and in a fluidi~ed bed at an air velocity o-f more than 2 Gmf, respectively, these being shown in comparison with those attained in a moving bed (indicated by the solid line). As ~his graph shows, the variation in the heat trans-~er co-efficients resulting from changes in the air veloc:Lty isslight (or the gradient is extremely gentle), and although any variation in the heat transfer coe-~ficient in accordance with air velocity will become quite considerable in the 2~03~

transLt:Lonal area between the eixed bed and the flll:Ldized bed, the range o~ air velocity corresponding to this transi-t:Lonal area is so small that control of the heat transfer coef-ficient at the -fixed bed, -fluidized bed or the transi-tional area is not of any practical sLgnificance.
Since operation of the bo:Ller C shown in Fig. 2e is identical to that o-f the boiler ~ which has already been explained, an explanation Oe it will no-t be given here.
As described above, the technica:L means of varying the velocity of the heat recovery air ln the therrnal energy recovery chamber is, as compared w:Lth the conventLonal stepwise intermittently controLled heat recovery in which the bed condition of the fluidizing medium in the thermal energy recovery chamber Ls varied only between a fluidized bed condition having an extremely high heat transfer coe-f-f:Lcient and a -fixed bed condition having an ex-tremely low heat transfer coe-f-ficient, capab]e Oe controlling the heat trans-fer coef-ficient steplessly and linearly and over a wide range. Further, since the technical means o-E varying the velocity o-f the heat recovery air in the thermal energy recovery chamber is, as shown in ~ig. 3B, capable o-f controlling the amount of the circulating fluidizing medium, -fine control over a wide range is made possible by -these technical means as a multiplied ef-fect o-f the control of the heat trans-fer coefficient and the control of the amount o-f the circulating fluidizing medium. Therefore, coupled with the technical idea that the amount o-f the heat recovery air supplied to the -thermal ener~y recovery chamber is determined by the steam pressure dependent heat recovery air supply control means and can be rapidly increased or decreased, the present invention provides an operational effect that the variation of the steam pressure in the boiler drum due to variation of the steam load can be more precisely and rapidly controlled than in the conventional apparatuses.
The concrete constitution and operation O:e an incineration control apparatus B according to the present invention will now be explained. It is to be noted that the 20n~38~B

snme re:~erence numerals and ref'erence symbols are used in the following explanation -to desigrlate components whl.ch are the same as those already referred to :Ln the descrlption o-f.
Figs. 5A and 5~ illustrate the first embod:Lment O-e the incineration control apparatus according to the present invention as applied to the boilers A and C. The outpu-t terminal o-f the pressure gauge 20b contained in the steam pipe 20 is connected to a termi.nal for inputting input signal PV01 to the pressure controller 31 which serves as means for controlling the amount of combustib:Les supplied and a terminal for inpwtting the set pressure value SV01 -to the pressure controller 31 :Ls in turn connected to the so-urce of relevant set pressure va:Lue signals. The term:Lnal for the operational output signal MV01 erom the pressure controller 31 is connected to the input terminal of a signal inver-ter 32 which serves as a means for controlling the set temperature value as well as to a mo-tor 12 incorporated in the combustion supply means 14 at an intermediate position toward the branch to the signal inverter.
The output O-e the signal inverter 32 i9 connected to the terminal for the set temperature value input signal SV02 to a temperature controller 33, and the temperature sensor 3a that serves as a means for detecting the temperature in the incineration chamber 3 is connected to the terminal for inputting the input signal SV02 to the temperature control~
ler 33. The terminal for the operational output signal MV02 from the temperature controller 33 is connected to the termi.nal for inputting the set flow rate value input signal SV03 to a flow rate cont,roller 34.
The terminal for the operational output signal MV03 from the flow rate controller 34 is connected to the control terminal of the control valve 9a contained in the heat recovery air pipe 9 and the terminal for inputting the input signal PV03 to the flow rate controller 34 is connected to the output terminal of the flow meter 9b contained in the air pipe 9. The temperature controller 33, flow controller 34, control valve 9a and flow meter 9b contained in the air pipe 9 together constitute a means for controlling ~0(~3~
~20-the air supply Por heat recovery. In addition, they also const:Ltute, together with the combustibles supply contro:L
means 31 an~ the set temperature value control means 32, means -for controll:Lng air supply -for heat recovery in accordance with steam pressure.
Opera-tion o-~ the :lncineration control apparatus shown in Figs. 5A and 5B will next be explained. ~s the steam load increases, the steam pressure detected by the pressure gauge 20b in the steam pipe 20 will be reduced, and the signal PV01 inpu-t to the pressure controller 31 will thus be reduced too. Then, s:Lnce the input signal PV01 w:il] beco~ne smaller relative to the pressure se-t value signal SV0:L which is set at a constant value, the operational output signal MV01 -from -the pressure controller 31 shows a tendency to rise, -thereby increasing the rotational speed o-f the motor 12 in the combustion supply means 14. In 1;his way, the operational speed of a screw type -feeder 13 will be increas-ed in order to increase the amount o-P combustibles supplied, whereby incineration in the incineration chamber can be made more active. Thus, the temperature o~ the -~luidized bed in the incineration chamber 3 will be raised in the long run and, as a result, the amount o-f heat received by the boiler drum -from the incineration chamber 3 will also increase, so that the steam pressure in the boiler drum 17 w:Lll gradually increase and return to its previous level.
While the above-mentioned operation is ta~ing place, in the short term the signal inverter 32 will respond to the operational output signal MV01 from the pressure controller 31 and supply the output signals thereof to the temperature controller 33 as the set temperature value signal SV02 -for the temperature controller, thereby enabling changes in the set temperature value. More specifically, the signal inverter 32 has input/output characteristics such as those shown in Fig. 6, so it will receive as an input signal the operational output signal MV01 -from the pressure controller 31 which varies in the range o-~ from 0% to 100%, and will output the temperature set value signal SV02 corresponding to a temperature in the range O-r -from 800~C to 850~C to the 20(:)38~3 temperature con-troller 33. S:Lnce the operational outpu-t signal MV01 has a tendency to increase :Ln the example o-~operation explained, -the point at wh:Lch the signal inverter will be activated will shift in the direction indicated by the arrow in Fig. 6, and the set temperature value signaL
SV02 supplied to the temperature controller will thus change to a lower value. It should be understood here that the varlation range o-f the set temperature value signal SV02 corresponding to the variation range of 0% tc 100% -eor the operational output sigllal ~V01 has been selected as 800~C -850~C based on the knowledge tha-t operation o-f the -fluidlzed bed in the temperature range is preferable -froln varlous points of view, such as better lnc:Lnera-tion e-f-f:Lc:Lency, prevention o-f sLntering of the :OEluidized bed, be-tter desul--furi~ation ef-ficiency (in -the case O-e coal burning), preven-tion o-f carbon monox:Lde generation (in the case of coaL
burning) and so forth.
When the set temperature value signal SV02 in the temperature controller 33 is reduced, then the input signal PV02 from the temperature sensor 3a and -the set temperature value signal SV02 in the temperature controller 33 do not match, so the temperature controller 33 will be caused to operate to reduce this d:Lf-ference by increasing the opera-tional output signal MV02.
Then, since larger set flow values have been established at the -flow controller 34 which receives the increased operational output signal MV02 as the set -flow rate value signal SV03, the operational output signal MV03 will be increased so as to match the input signal PV03 from the -flow meter 9b with the newly established set value.
Thus the opening degree of the control valve 9a will be increased and the velocity of the heat recovery air which is fed to the air dispersion plate 8 via the heat recovery air pipe 9 and then Jets into the heat recovery chamber 4 will be increased.
Consequently as clearly seen -from the graph sho~n in Fig. 4 already explained, the heat transfer coe~-ficient o-f the moving bed in the heat recovery chamber 4 will also have ~0038~3 a tendency to :lncrease :ln accordance w:l-th the tendency of the velocity o~ the heat recovery air and the amount of thermal energy trans-~erred to the boiler drum 17 from the heat recovery chamber 4 through the heat recovery tube 10 will also be increased.
Increasing the amount o-~ thermal energy in accordance with the veloc:Lty of the heat recovery air as above explained may enable the steam pressure to be increased and restored to its previous ]evel eor a short period of time in such a manner as to discharge hea-t accumulated in the moving bed in the heat recovery chamber 4 to the heat recovery tube 10. Eowever, this only occurs momentarily before the steam pressure increases in accordance with the amount of combus-tibles supplied, whlch takes a :Longer tlme, as already explained.
When the steam pressure has been raised and re-turns to its previous level, the input signal PV01 to the the pressure controller 31 from the pressure gauge 20b will also exhibit a tendency to increase. Since the pressure control-ler 31 will be balanced at the point where the input signalPV01 has increased to match the predetermined set pressure value signal SV01, the operational output signal MV01 f'rom the pressure controller 31 will become settled at the medlan point (50%). Correspondingly, the amount O-r combustibles to be supplied to the combustibles supply means 14 will also be reset to the median (50%) and at this time, in correlation ; therewith, the air velocity of the heat recovery air at the air dispersion plate in the heat recovery chamber 4 will also be returned close to the median (50%). The operation explained above is exercised as a response of the system to any external disturbance due to a reduction in steam pres-sure. The operation ~ill of course be reversed in response to any external disturbance due to an increase in steam pressure.
In summary, the incineration control apparatus according to the present invention is applied to a fluidized bed type boiler having an incineration chamber 3 filled with fluidizing medium and adapted to incinerate combustibles ~o~

and a heat recovery chamber ~ locate~ adJacent to the incineration chamber and de~'ined :Ln such a manner as to enable the fluidizirlg med:Lum :Ln -the incineration chamber to be circulated thereto and capable of recovering the heat in the -fluidizing medium in the hea-t recovery chamber and trans-ferring it to the boiler d:rum 17 through the heat recovery means 10 and 11 provided :Ln the heat recovery chamber in accordance with the amount o:f heat recovery air supplied in the heat recovery chamber 4 from the heat recov-ery air supply means 6a, 8, 8a, 8a' and 8b provided :Ln the hea-t recovery chamber, the inci:neration control appara-tus being so constructed that the control means 31, 32, 33, 34, 9, 9a and 9b -~or controlling -the amount of heat recovery air supplied in accordance with the steam pressure con-tro:Ls the amount o-f air (or the air velocity) to be supplied into -the heat recovery chamber 4 in accordance wlth the steam pres-sure in response to the steam pressure signal PVOl -~rom the pressure gauge 20b which serves as the means -ror detecting the steam pressure. In this manner, the amount of thermal energy trans~erred to the boiler drum 17 ~rom the heat recovery chamber 4 may be controlled in accordance with the steam pressure. Typically, the amount o-f combusti.bles supplied may be controlled in accordance with the steam pressure in such a way that the pressure controller 31 servin~ as the control means ~or controlling the amount of combustibles supplied will provide the operational output signal MVOl to the combustibles supply means 14 so that the steam pressure signal PVOl ~rom the pressure gauge 20b servlng as the steam pressure detecting means may be balanced relative to the set pressure value signal SVOl.
On the other hand, the temperature controller 33 serving as the heat recovery air supply control means 33, 34, 9, 9a, 9b will supply the operational output signal MV02 to the flow controller 3~ as the set value signal SV03 so that the tempera-ture signal PV02 ~rom the temperature detecting means 3a may be balanced rela-tive to the set temperature value signal SV02. The flow controll.er 34 supplies the opera-tional output signal MVo3 to the control value 9a so that 3~3 -2~-the (a:ir) flow s:Lgna:l PV()3 Prom the f:Low meter 9b may be balanced relative to the set va].ue s:Lgnal SV03, varies the amoun-t (air velocity) of a:Lr supplied into the heat recovery chamber 4 and controls the anlount of thermal energy trans--ferred to the boiler drum 17 Prom tlle heat recovery chamber 4 in accordance with the temperature. Two kinds o-f con-trol operations as above explained may be interrelated by corre-lating the operational output signal MV01 -from the pressure controller 31 with the set value signal SV02 suppl:Led to the temperature controller 33 by the signal inver-ter 32 as t~e set temperature contro.L means. In this way, while a control operation serving -to execute long term control is executed by the pressure controller 31 acting as the combust:Lbles supply contro:L means to constantly secure the correct amoun-t o-f combustibles irrespect:lve of :Lncreases or decreases in the steam pressure caused by variations in -the steam load, the amount (or air velocity) of heat recovery air suppl:ied :Lnto the heat recovery chamber 4 may be increased or decreased ~or a shor-t period o-f time in accordance with the steam pressure, so that -the heat accumulated in the -fluidiz-ing medium in the heat recovery chamber ~ may be trans-ferred to -the boiler drum 17 in such a manner ns to be discharged momentarily, or heat supply to the boiler drum 17 may be restricted in such a manner as to accumulate heat momen-tarily in the -fluidizing medium. Thus the operation oP
controlling the steam pressure may be rapidly executed whenever there is a variation in the steam load.
It is to be noted, however, that in the incineration control apparatuses shown in Figs. 5A and 5B, since the amount of combustibles to be supplied is controlled solely on the basis oP steam pressure, when it is necessary to constantly control the amount of combustibles supplied in the -Pace of variations in the steam load or steam pressure over a long period of time, it becomes necessary to constantly adJust the amount of combustibles supplied by the combustibles supply means 14 which involves nlaking the control of the steam pressure at the pressure controller 31 out of balance. As a result, with regard to the control of ~o~

the steam pressure on the basis of -the veloci-ty of the heat recovery air through cooperation between the temperature controller 33 and the -flow controller 34, it has to be taken into consideration that keeping the air velocity Oe the heat recovery air near the median (or 50%) in the -~ace of external disturbances will become impossible and that it will be di-~flcult to uniformly achieve maximi~at:Lon o-f the amount of thermal energy recovered and trans-ferred to the boiler drum 17 which may :lnvolve both increases and decreases o-f such amount.
F'igs. 7A and 7B illustrate a second embodiment o-f an incineration control apparatus according to the present invention which can be appl:Led respec-tively to the boi.Ler A
shown in Fig. 2A and the boiler C shown in ~ig. 2B.
In Fig. 7A, an output terminal of a flow meter 20a contained in a steam pipe 20 is connected to one of the input terminals o-f a computing eLement 35 which serves as a means -for control:Ling the amount of combustibles supplied on the basis o-~ a steam load, while the other input terminal of the computing element 35 is connected to a terminal -for the operational output signal MV01 -from a pressure controller 31. An output terminal o-f the computing element 35 is connected to a motor 12 o-f a combustibles supply means 14.
The remaining constitution is identical to that of the first embodiment shown in Figs. 5A and 5B.
Operation o-f the incineration control apparatus shown in Fig. 7A will now be explained. As the steam load is increased, the steam pressure which is detected by the pressure gauge 20b will decrease and the opera-tional output signal MVOl -from the pressure controller 31 will thus have a tendency to increase. This is the same as the case of the first embodiment (shown in Figs. 5A and 5B). However, the operational output signal MV01 is not provided directly to the motor 12 o-f the combustibles supply means 14 like in the first embodiment, but is instead supplied to the other input terminal o-f the computing element 35.
During this time, since an output signal -~rom the -flow meter 20a contained iIl the steam pipe 20 i5 supplied 2~
-2~-as an input signal PV04 ind:Lcating -that the stea~ -elow rate has a tendency to increase, the computing element 35 w:ill calculate the arithmetic output signal YO expressed ln the -~ollowing equation in accordance with the input signal PV04 and the operational output signal MV01 and supply them to the motor 12.
Y0 = PV04 ~ a(2MV01 -- 100) wherein "a" = a constant value, thus determlning the varia-tion range of the arithmetic output signal Y0.
An explanation will now be glven regarding how -the arithmetic output signa:L Y0 is determined by the signa:L PV04 and ~V01 provLded by the ~'Low meter 20a and the pressure contro]ler 31, referring to Figs. 8 and 9.
Fig. 8 is a graph show:ing the relationsh:Lp between the operational output signal MV01 supplied to the other input terminal of the computing element 35 and the arith-metic output signal Y0 -from the computing element. The operation point Pl which represents a normal condition wherein the operational output signal MV01 from the pressure controller 31 is settled at 50% is located on the character-istic curve shown by the solid line, and the arithmetic output signal Y0 on the abscis~a corresponding to the point Pl may thus be defined. As is clear -from the above-mentioned equation, the arithmetic output signal Y0 is also governed by the input signal PV04 supplied to one o~ the input terminals of the computing element 35.
Fig. 9 is a graph showing the relationship between the steam flow rate (PV04) detected by the ~low meter 20a and the amount of combustibles supplied (%~ or the arith-metic output signal Y0 supplied to the combustibles supplymeans 14, -from the computing element 35. Since this relationship is included in the input and output character-istics of the computing element 35 as being governed by the input signal PV04~ if the steam -~low rate (PV04) is Ql at a normal condition, i.e. at 50%, the operation point ql is located on the characteristic curve and the arithmetic output signal YOl on the abscissa corresponding to the operation point may be defined. It will be understood 2~

that the arithmetlc ou-tput sLgnal YOl co:Lncides with the arithmetic output s:ignal YOl corresponcling -to the operat-lon point Pl on the characteristic line inclicated by -the solid line in F:Lg. 8.
When the steam load increases and the steam flow ra-te (PVOA) is increased in stepwise fashion from Ql to Q2, then the operation point is sh:ifted -from ql to q2 on -the charac-teristic line in Fig. 9. Accor-dingly, since the value of the arithmetic output signal YO increases in stepwise fashion -from YOl to Y02, -the characteristic line drawn as a solid line in Fig. ~ will be shifted upwardly and rightward-ly in the drawing to the position of the characteristic lLne drawn as a dotted l:Lne and consequently the operat:Lon point Pl w:Lll be immed:Lately shifted to the operation point P2.
Since the steam pressure will respond to increases in the steam flow rate (YV04) accompanied by an increase in the steam load in an integral manner, the steam pressure will drop temporarily and the input signal PVOL ~rom the pressure gauge 20b to the pressure controller 31 will also be reduced. In response -to -this reduction, the operational output signal MVOl from the pressure controller 31 will be gradually increased and the operation point P2 on the characteristic line drawn as a dotted line in Fig. 8 will also be raised along the charac-teristic line to the opera-tion point P'2 for example. Accordingly, the arithmeticoutput signal YO on the abscissa in Fig. B will be gradually increased to the point Y02'.
Subsequently, in response to the gradual increase in the arithmetic output signal YO, the speed of the motor 12 will increase and the amoun-t o-f combustibles supplied by the combustibles supply means 14 will also be increased, whereby incineration in the incineration chamber 3 will become active and an increased amount of evaporation will be generated in the boiler drum 17. This will in turn cause the steam pressure to gradually rise and, in the long run, the operational output signal MVOl from the pressure controller 31 will be forced up to the value O-r 50% at the ~20~3~

time where the pressure control:Ler 31 :Ls in a balanced condition and will settle at that value.
During -this operation, the cooperation O-e the signal inverter 32, which respon~s concurrently -to gradual increases in the arithmetic output signal YO by causin~ an increase in the operatlonal output signal MV01, with the temperature controller 33 and the flow controller 34 will control the amount o-f thermal energy transferred to the boiler drum 17 from the heat recovery chamber 4, as already explalned, whereby the balancing operat:Lon conducted by the pressure controller 31 will be tac:Llitated.
Accordingly the operation point P2' which has once been raised along the character:Lstic curve drawn as a dotted line in Fig~ 8 wil:l be forced downward:Ly to settle at -the operation point P2. The arithmetic output signal YO corre-sponding to the operation point P2 will at this t:Lme settle at -the value YO2 to secure the operation point q2 corre-sponding to the steam -flow rate Q2 which is constantly increasing along the characteristic line shown in Fig. ~.
Thus, when the amount o-f combustibles supplied by the combustibles supply means 14 is increased or decreased by the constant changing of the value of the arithmetic output signal YO from the computing element 35 in response to the constant variations in the steam load, the operational output signal MV01 from the pressure controller 31 may be constantly forced down to the value of 50%.
This will enable the variable amount o-f thermal energy recovered and transferred to the boiler drum 17 from the heat recovery chamber 4 to be maximized uni-formly whether increases or decreases in this amount are taking place since the velocity of the heat recovery air is kept constantly at the median point thereo-f within controllable range with the steam pressure in a normal condition. This is possible because the steam pressure is rapidly restored to the previous level when an increase or decrease occurs, this being achieved by causing an instantaneous increase or reduction in the amount of thermal energy in accordance with ~6~03~

the velocity Or -the heat recovery alr throu~h the coopera-tlon Oe the signal inverter 32, the temperature control:Ler 33 and the -rlow controller 34, which operate in the same manner as in the first embodiment (illustrated in Figs. 5A
and 5B).
The second embodiment of the lncinera-tion control apparatus according to the present invention as app]ied to the boiler A shown in Fig. 2A has been explained with refer-ence to ~ig. 7A. Since application oE the control apparatus to the boiler C shown in Fig. 2B is similar to the above application, explanatlon o-~ the incineratlon con-trol appa-ratus shown in Fig. 7B :Ls ornitted here.
In summary, according -to the second embodiment of the incineration control apparatus according to the present invent:Lon, the computing element 35 which serves as the combustibles supply control means -for controlling the amount of combustibles supplied on the basis o-f steam load computes and generates the arithmetic output signal YO required -ror securing constant adJustment o~ the amoun-t of combustibles supplied in correspondence with the constant variations in the steam load which depend on the steam flow rate when supplied with the operational output signal MV01 (50%) from the pressure controller 31 which serves as the combustibles supply control means during the time when the system is in a balanced condition, this signal then being output to the combustibles supply means 14. This will cause the pressure controller 31 to be kept constantly balanced in the normal condition regardless of the prevailing steam load or the amount of combustibles supplied, keep the operational output signal ~V01 at the value of 50%, bring the amount of heat recovery air supplied (or the air velocity) close to the median of 50% at the heat recovery air supply control means 33, 34, 9, 9a and 9b which respond to the operational output signal MV01, and thus uniformly maximize the range O-r varia-tion in the amount of heat recovery air supplied whether theamount thereof is increasing or decreasing.
According to the second embodiment of the incinera-tion control apparatus of the present invention, i-r there is Z(~03~3 a constan-t amoun-t of the flu:ldiz:Lng medium which -flows from the inc:Lneration chamber 3 to the heat recovery chamber 4 (the constant amount being determined by the incineration air velocity which is -fixedly set), -this will cause the heat accumulated in the -fluidizinK medium contained :Ln the moving bed in the heat recovery chamber to be discharged momentar-ily so as to be trans-ferred to the bo:L:Ler drum 17. Ilowever, the amount of -fluidizing medium which may be diverted -from the inc:ineration chamber 3 to the heat recovery chamber 4 is not controlled at all. Accordingly, the amount o-f thermal energy may be advantageously lncreased or decreased due to a variat:Lon in the velocity of the heat recovery air when there is a balanced condi-tion a-t each of the heat recovery air supply control means 33, 34, 9, 9a and 9b. ~lowever, since the thermal energy accumulated in -the flu:Ldizing medium contained in the moving bed in the heat recovery chamber 3 i9 not fully controlled, when the skeam pressure is restored to the normal condi-tion -following an external disturbance which causes an increase in pressure, the amount of thermal energy accumulated in the heat recovery chamber 4 will be so little that there may be di-f-ficulty in momentar-ily restoring the steam pressure.
Figs. lOA and lOB illustrate the constitution o-f a third embodiment of the incineration control apparatus according to the present invention which is applied to the boiler A shown in Fig. 2A and the boiler C shown in Fig. 2B.
The dif-ference between the third embodiment and the second embodiment shown in Flgs. 7A and 7B resides in that the signal line connected from the output termina] o-f the computing element 35 to the motor 12 incorporated in the combustibles supply means 14 is also branched at a point along it before it reaches the motor, this branch leading to the terminal for the -flow set value signal SV05 -for the incineration air supply -flow controller 36.
In the incineration air supply pipe 7 ex-tending to the air chamber 6 from a incineration air source not shown in the drawing, there are a control valve 37 and a flow meter 38 provided in that order toward an air chamber 6.

3~

The terminal for a operat:Lon output s:lg~a:l MV05 of a inc:Ln~
eratLon a:Lr flow controller 36 ls connected to the control termlnal of a control valve 37 ancl the output termLnal of the flow meter 38 is connected to the terminal for a input signal PV05 o-f the -flow controller 36. The -flow controller 36, the control valve 37 in the incineration air pipe 7 and the flow meter 38 in the air pipe constitute a incineration air supply control means.
According to the constitu-tion as explained above, at the time of momentary increase or decrease of the stealrl load, as the steam -flow rate detected by the -f]ow meter ZOa increases or decreases, -the input signal PV04 to the comput-ing element 35 will be increased or decreased and in re-sponse there-to the computing element w:Lll shi~t momentari:ly the operation po:Lnt on the characteristic curve shown in Fig. 8 upwardly elther le-ftwardly or rightwardly so as to instantaneously increase or decrease the arithmetic output signal YO from the computing element 35. This will ensure momentary restoration o-f the steam pressure. On the other hand, if the steam pressure detected by the pressure gauge 20b depending on the normal change o-f the steam load is increased or decreased in a normal manner, the computing element 35 will vary the position o-f stable operation at the time of balanced condition o-f the pressure controller 31 depending on the amount of the steam flow and provide to the electric motor 12 normal arithmetic outpu-t signal YO corre-sponding to the increased or decreased steam load. This will ensure a control operation for the steam pressure for a long period of time. Since such output signal YO from the computing element 35 is also suppl:ied to the incineration air supply -flow controller 36 as a flow rate set value signal SV05, supposing that the steam load is increased so that the amount of combustibles supplied by the combustibles supply means 14 will show a sign o-f increase, the flow rate set value signal SV05 which is the output signal from the computing element 35 will also show a sign o-f increase.
Consequently since the inp~lt signal PV05 will not coincide with the -flow rate set value signal SV05 at the -flow 20038~3 controller 3~, the ~].ow rate control:ler 36 wi:l:L increase the opcrational output signal MV05 and increase opening degree o e the control valve 37.
As a result, when the steam load is normally increased and the amount o-f the supplied combustible is also increased normally, then the opening degree of the control valve 37 is also normally increased, so that the velocity o-f the incineration air which is inJected into the incineration chamber 3 from the air chamber 6 through the incineration air pipe 7 will also be increased. According to the opera-tion point on the operational curve as explained with refer-ence to Fig. 3A will be shifted :ln the direction indicated by the arrow shown in Flg. 3A and the amount of the -fluidiz-ing medium which :Elows from the incineration chamber 3 to the heat recovery chamber 4 will be increased, so that the parameter (or -the amount of circu]ation of the -fluidizing medium) in the operation curves illustrated in Fig. 3B as explained already will correspondingly be increased and the operational curves o-f the operation in question will be moved in the direction indicated by the arrow.
Therefore, the amount o-f the -fluidizing medium flow-ing from the heat recovery chamber 4 to the incineration chamber 3 or the amount o-f circulation of the fluidizing medium will be increased and such -fluidizing medium will be carried to the fluidizing medium contained in the moving bed in the heat recovery chamber 4, ca-using the thermal energy accumulated in the moving bed to be increased and restr:ict-ing reduction of the temperature o-f the moving bed varying depending on the recovery thermal energy to keep the temper-ature at a high level.
Since the heating value R recovered into the boilerdrum 17 from the heat recovery chamber 4 is expressed by the equation:
R = A*~*~T
where A = the ef-fective heat receiving area o-f the heat recovery tube lO
~ = coefficient of heat transfer ;.

382~

~ T = dle-ference in temperature betw~en the -~luidl~lng medlum in the movlng bed ln the heat recovery chamber 4 and the s-team ln the boller drum 17, main-tenance at a high level of the temperature o-f the -~lu:Ld-izing medium in the moving bed in the heat recovery chamber 4 means that more thermal energy may be recovered. Thus even if the steam load is usually excessive su-f:eicient recovery of the thermal energy into the boiler drum -Prom the heat recovery chamber 4 may ensure a quick restoration 0 o-f the steam pressure.
As clearly seen -erom the eoregoing explanation, ln the third embodiment o-f the incineration control apparatus according to the present inven-tion, the incineration air supply control mearls 7, 36, 37 and 38 will respond to the continuously increasing arithmetic output signal YO supplied -from -the computing e]ement 35 lncluded in the means -for controlling the amount o-f combustible supplied depending on the steam load when the steam load is increasing in a normal manner, increase the amount of the incineration air supply (or the velocity of air ~or incineration) into the incinera-tion chamber 3, increase the amount o-f' the -fluidizing medium circulating in the heat recovery chamber 4 and increase the thermal energy carried -from the incineration chamber 3 and stored in the -fluidizing medium. This will ensure su-ffi-cient amount of the thermal energy recovered into the boilerdrum 17 from the heat recovery chamber 4 even i-f the steam load is normally excessive, whereby upward restoration o*
the steam pressure due to insu-fficient thermal energy recovered may be prevented from being delayed.
POSSIBILITY OF INDUSTRIAL UTILIZATION:
According to the present invention, since the steam pressure in the boiler drum is correlated to control of the thermal energy recovered into the boiler drum, so that response of control of the steam pressure against variation caused by variation of the steam load is enhanced, the present invention may be applied to the control means in a 20~)38~

-Pluid:Lzed bed type boiler adapted to inc:Lnerate such combus-t:ible as municipal re-Puse, industr:Lal waste, coal or -the like.

Claims (21)

1. An incineration control apparatus for a fluidized bed type boiler comprising:
an incineration chamber (3) filled with fluidizing medium for incinerating combustibles in said fluidizing medium;
combustibles supply means (14) for supplying a specified amount of combustibles to said incineration chamber (3);
incineration air supply means (5, 5a, 6, 7) for supplying incineration air to said incineration chamber (3);
a boiler drum (17) for receiving heat from said incineration chamber (3);
a heat recovery chamber (4) adjacent to said incineration chamber (3) and so defined that said fluidizing medium in said incineration chamber (3) may be circulated therethrough;
heat recovery air supply means (6a, 8, 8a, 8a', 8b) for supplying heat recovery air to said heat recovery chamber (4) at a specified air velocity (or mass velocity);
heat recovery means (10, 11) provided in said heat recovery chamber (4) for recovering and transferring to said boiler drum (17) the heat in said fluidizing medium circulating through said heat recovery chamber (4) in accordance with the specified velocity (or mass velocity) of the heat recovery air;
steam pressure detecting means (20b) for detecting the steam pressure in said boiler drum (17) and for outputting a steam pressure signal (PV01) indicating said steam pressure; and steam pressure dependent heat recovery air supply control means (31, 32, 33, 34, 9, 9a, 9b) adapted to respond to said steam pressure signal (PV01) and to control the velocity (mass velocity) of the heat recovery air at said heat recovery air supply means (6a, 8, 8a, 8a', 8b) on the basis of steam pressure.
2. An incineration control apparatus as claimed in Claim 1, wherein said steam pressure detecting means comprises a pressure gauge disposed in a steam pipe (20) connecting said boiler drum (17) to a steam pressure load (21).
3. An incineration control apparatus as claimed in Claim 2, wherein said steam pressure dependent heat recovery air supply control means supplies to said combustibles supply means (14) an operational output signal (MV01) for controlling the supply amount of combustibles in response to the steam pressure signal (PV01) output from said pressure gauge.
4. An incineration control apparatus as claimed in Claim 3 further including a temperature sensor (3a) for detecting the temperature in said incineration chamber (3) and for outputting a temperature signal (PV02) indicating said temperature, wherein said steam pressure dependent heat recovery air supply control means includes heat recovery air supply control means (33, 34, 9a, 9b) which respond to said steam pressure signal (PV01) and said temperature signal (PV02) and control the velocity (or mass velocity) of heat recovery air at said heat recovery air supply means (6a, 8, 8a, 8a', 8b) such as to cause the temperature in said incineration chamber (3) to coincide with a specified temperature set value.
5. An incineration control apparatus as claimed in any one of Claims 1 to 4, wherein said fluidizing medium circulating through said heat recovery chamber (4) forms a moving bed which moves from upward to downward in said chamber.
6. An incineration control apparatus for a fluidized bed type boiler comprising:
an incineration chamber (3) filled with fluidizing medium for incinerating combustibles in said fluidizing medium;
combustibles supply means (14) for supplying a specified amount of combustibles to said incineration chamber (3);

incineration air supply means (5, 5a, 6, 7) for supplying incineration air to said incineration chamber (3);
a boiler drum (17) for receiving heat from said incineration chamber (3);
a heat recovery chamber (4) adjacent to said incineration chamber (3) and so defined that said fluidizing medium in said incineration chamber (3) may be circulated therethrough;
heat recovery air supply means (6a, 8, 8a, 8a', 8b) for supplying heat recovery air to said heat recovery chamber (4) at a specified air velocity (or mass velocity);
heat recovery means (10, 11) provided in said heat recovery chamber (4) for recovering and transferring the heat in said fluidizing medium circulating through said heat recovery chamber (4) to said boiler drum (17) in accordance with the specified velocity (or mass velocity) of the heat recovery air;
steam pressure detecting means (20b) for detecting the steam pressure in said boiler drum (17) and for outputting a steam pressure signal (PV01) indicating said steam pressure;
combustibles supply control means (31) for controlling the amount of combustibles supplied by combustibles supply means (14) in response to said steam pressure signal (PV01);
temperature detecting means (3a) for detecting the temperature in said incineration chamber (3) and for outputting a temperature signal (PV02) indicating said temperature;
heat recovery air supply control means (33, 34, 9, 9a, 9b) for controlling the velocity (or mass velocity) of heat recovery air at said heat recovery air supply means (6a, 8, 8a, 8a', 8b) in response to said temperature signal (PV02) such as to cause temperature indicated by said temperature signal to coincide with a specified temperature set value; and temperature set value control means (32) for controlling a temperature set value at the heat recovery air supply control means (33, 34, 9, 9a, 9b) in unison with control of the amount of combustibles supplied by said combustibles supply means (14) which is controlled by said combustibles supply control means (31).
7. An incineration control apparatus as claimed in Claim 6, wherein said steam pressure detecting means comprises a pressure gauge (20b) disposed in a steam pipe (20) connecting said boiler drum (17) to a steam pressure load, and said temperature detecting means comprises a temperature sensor (3a) disposed in said incineration chamber (3).
8. An incineration control apparatus as claimed in Claim 7, wherein said specified temperature set value is a temperature set value (SV02) corresponding to the output from said combustibles supply control means (31), and said heat recovery air supply control means comprises a temperature controller (33) adapted to receive said specified temperature set value signal (SV02) and the temperature signal (PV02) from said temperature sensor (3a) and output a flow rate set value signal (MV02) indicating the flow rate set value, and comprises a flow rate controller (34) adapted to receive said flow rate set value signal (MV02) and control the flow rate of the heat recovery air by regulating the opening rate of a control valve (9a) provided in an air pipe (9) such as to cause said velocity of heat recovery air to coincide with said flow rate set value signal (MV02).
9. An incineration control apparatus as claimed in Claim 6, wherein said temperature set value control means comprises an inverter (32) adapted to invert the output from said combustibles supply control means (31).
10. An incineration control apparatus for a fluidized bed type boiler comprising:
an incineration chamber (3) filled with fluidizing medium for incinerating combustibles in said fluidizing medium;
combustibles supply means (14) for supplying a specified amount of combustibles to said incineration chamber (3);

incineration air supply means (5, 5a, 6, 7) for supplying incineration air to said incineration chamber (3);
a boiler drum (17) for receiving heat from said incineration chamber (3);
a heat recovery chamber (4) adjacent to said incineration chamber (3) and so defined that said fluidizing medium in said incineration chamber (3) may be circulated therethrough;
heat recovery air supply means (6a, 8, 8a, 8a', 8b) for supplying heat recovery air to said heat recovery chamber (4) at a specified air velocity (or mass velocity);
heat recovery means (10, 11) disposed in said heat recovery chamber (4) for recovering and transferring the heat in said fluidizing medium circulating through said heat recovery chamber (4) to said boiler drum (17) in accordance with the specified velocity (or mass velocity) of the heat recovery air;
steam pressure detecting means (20b) for detecting the steam pressure in said boiler drum (17) and for outputting a steam pressure signal (PV01) indicating said steam pressure;
combustibles supply control means (31) for controlling the amount of combustibles supplied by said combustibles supply means (14) in response to said steam pressure signal (PV01);
temperature detecting means (3a) for detecting the temperature in said incineration chamber (3) and for outputting a temperature signal (PV02) indicating said temperature;
heat recovery air supply control means (33, 34, 9, 9a, 9b) for controlling the velocity (or mass velocity) of heat recovery air at said heat recovery air supply means (6a, 8, 8a, 8a', 8b) in response to said temperature signal (PV02) such as to cause temperature indicated by said temperature signal to coincide with a specified temperature set value;
temperature set value control means (32) for controlling a temperature set value at said heat recovery air supply control means (33, 34, 9, 9a, 9b) in unison with control of the amount of combustibles supplied by said combustibles supply means (14) which is controlled by said combustibles supply control means (31);
steam flow rate detecting means (20a) for detecting flow rate of the steam from said boiler drum (17) to a steam load and for outputting a steam flow rate signal (PV04) indicating said flow rate; and steam load dependent combustibles supply control means (35) for controlling the amount of combustibles supplied by the combustibles supply means (14) depending on the flow rate of steam indicated by said steam flow rate signal (PV04) depending on the steam load in addition to control by said combustible supply control means (31) for controlling the amount of combustibles supplied by said combustibles supply means (14).
11. An incineration control apparatus as claimed in Claim 10, wherein said steam pressure detecting means comprises a pressure gauge (20b) disposed in a steam pipe (20) connecting said boiler drum (17) to said steam load and said temperature detecting means comprises a temperature sensor (3a) disposed in said incineration chamber (3).
12. An incineration control apparatus as claimed in Claim 11, wherein said specified temperature set value is a temperature set value (SV02) corresponding to the output from said combustibles supply control means (31), and said heat recovery air supply control means comprises a temperature controller (33) adapted to receive said specified temperature set value signal (SV02) and temperature signal (PV02) from said temperature sensor (3a) and output a flow rate set value signal (MV02) indicating the flow rate set value, and comprises a flow rate controller (34) adapted to receive said flow rate set value signal (MV02) and control the flow rate of the heat recovery air by regulating the opening rate of a control valve (9a) disposed in an air tube (9) such as to cause said velocity of heat recovery air to coincide with said flow rate set value signal (MV02).
13. An incineration control apparatus as claimed in Claim 10, wherein said temperature set value control means comprises an inverter (32) adapted to invert the output from said combustibles supply control means (31).
14. An incineration control apparatus as claimed in Claim 10, wherein said steam load dependent combustibles supply control means is a computing element (35) adapted to receive an operational output signal (MV01) output from said combustibles supply control means (31) in response to said steam pressure signal (PV01) and said steam flow rate signal (PV04), and compute an output signal (Y0) applied to said combustibles supply means (14) in accordance with the formula of:
Y0 = PV04 + a(2MV01 - 100) where "a" is a coefficient of stipulating the variation range of Y0.
15. An incineration control apparatus for a fluidized bed type boiler comprising:
an incineration chamber (3) filled with fluidizing medium for incinerating combustibles in said fluidizing medium;
combustibles supply means (14) for supplying a specified amount of combustibles to said incineration chamber (3);
incineration air supply means (5, 5a, 6, 7) for supplying incineration air at a specified air velocity (or mass velocity) to said incineration chamber (3);
a boiler drum (17) for receiving heat from said incineration chamber (3);
a heat recovery chamber (4) adjacent to said incineration chamber (3) and so defined that said fluidizing medium in said incineration chamber (3) may be circulated therethrough;
heat recovery air supply means (6a, 8, 8a, 8a', 8b) for supplying heat recovery air to said heat recovery chamber (4) at a specified air velocity (or mass velocity);
heat recovery means (10, 11) provided in said heat recovery chamber (4) for recovering and transferring the heat in said fluidizing medium circulating through said heat recovery chamber (4) to said boiler drum (17) in accordance with the specified velocity (or mass velocity) of the heat recovery air;
steam pressure detecting means (20b) for detecting the steam pressure in said boiler drum (17) and for outputting a steam pressure signal (PV01) indicating said steam pressure;
combustibles supply control means (31) for controlling the amount of combustibles supplied by said combustibles supply means (14) in response to said steam pressure signal (PV01);
temperature detecting means (3a) for detecting the temperature in said incineration chamber (3) and for outputting a temperature signal (PV02) indicating said temperature;
heat recovery air supply control means (33, 34, 9, 9a, 9b) for controlling the air velocity (or mass velocity) for heat recovery at said heat recovery air supply means (6a, 8, 8a, 8a', 8b) in response to said temperature signal (PV02) such as to cause the temperature indicated by said temperature signal to coincide with a specified temperature set value;
temperature set value control means (32) for controlling a temperature set value at the heat recovery air supply control means (33, 34, 9, 9a, 9b) in unison with control of the amount of combustibles supplied by said combustibles supply means (14) which is controlled by said combustibles supply control means (31);
steam flow rate detecting means (20a) for detecting flow rate of the steam supplied from said boiler drum (17) to a steam load and for outputting a steam flow rate signal (PV04) indicating said flow rate;
steam load dependent combustibles supply control means (35) for controlling the amount of combustibles supplied by said combustibles supply means (14) in accordance with the flow rate of steam indicated by said steam flow rate signal (PV04) in accordance with the steam load in addition to control by said combustibles supply control means (31) which controls the amount of said combustibles supplied by said combustibles supply means (14); and incineration air supply control means (7, 36, 37, 38) for controlling the velocity (or mass velocity) of incineration air at said incineration air supply means (5, 5a, 6, 7), in unison with control of the amount of combustibles supplied by said combustibles supply means (14) under the control by said combustibles supply control means (31) and said steam load dependent combustibles supply control means (35).
16. An incineration control apparatus as claimed in Claim 15, wherein said steam pressure detecting means comprises a pressure gauge (20b) disposed in a steam pipe (20) connecting said boiler drum (17) to the steam load and said temperature detecting means includes a temperature sensor (3a) disposed in said incineration chamber (3).
17. An incineration control apparatus as claimed in Claim 16, wherein said specified temperature set value is a temperature set value (SV02) corresponding to the output from said combustibles supply control means (31), and said heat recovery air supply control means comprises a temperature controller (33) adapted to receive said specified temperature set value (SV02) and temperature signal (PV02) from said temperature sensor (3a) and output a flow rate set value signal (MV02) indicating the flow rate set value, and comprises a flow rate controller (34) adapted to receive said flow rate set value signal (MV02) and control the flow rate of the heat recovery air by regulating the opening rate of a control valve (9a) provided in an air pipe (9) such as to cause said velocity of the heat recovery air to coincide with said flow rate set value signal (MV02).
18. An incineration control apparatus as claimed in Claim 15, wherein said temperature set values control means comprises an inverter (32) adapted to invert the output from said combustibles supply control means (31).
19. An incineration control apparatus as claimed in Claim 15, wherein said steam load dependent combustibles supply control means is a computing element (35) adapted to receive the operational output signal (MV01) output from said combustibles supply control means (31) in response to said steam pressure signal (PV01), and said steam flow rate signal (PV04) and compute an operational output signal (Y0) applied to said combustibles supply means (14) in accordance with the formula of:
Y0 = PV04 + a(2M0V1 - 100) where "a" is a coefficient of stipulating the variation range of Y0.
20. An incineration control apparatus as claimed in Claim 19, wherein said incineration air supply control means comprises a control valve (37) adapted to control the flow rate of the incineration air supplied to-said incineration chamber (3), a flow meter (38) adapted to detect the flow rate of said incineration air and output the flow rate signal indicating the flow rate and a flow rate controller (36) adapted to receive said operational output signal (Y0) and said flow rate signal and regulate the opening rate of said control valve (37) so that said flow rate signal may coincide with said operational output signal.
21. An incineration control apparatus as claimed in any one of Claims 1 to 20, wherein said incineration air supply means (5, 5a, 6, 7) is adapted to supply the incineration air to said incineration chamber (3) at an air velocity more than 2 Gmf and said air supply heat recovery means (6, 8, 8a, 8a', 8b) is adapted to supply the heat recovery air to said heat recovery chamber (4) at a specified air velocity (or mass velocity) which is in a range from 0 Gmf to 2 Gmf.
CA 2003828 1989-11-24 1989-11-24 Incineration control apparatus for a fluidized bed boiler Expired - Fee Related CA2003828C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA 2003828 CA2003828C (en) 1989-11-24 1989-11-24 Incineration control apparatus for a fluidized bed boiler

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA 2003828 CA2003828C (en) 1989-11-24 1989-11-24 Incineration control apparatus for a fluidized bed boiler

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CA2003828A1 CA2003828A1 (en) 1991-05-24
CA2003828C true CA2003828C (en) 1999-05-11

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