WO2013024201A1 - Amélioration d'un transfert de chaleur d'un lit fluidisé vers une conduite d'échangeur de chaleur - Google Patents

Amélioration d'un transfert de chaleur d'un lit fluidisé vers une conduite d'échangeur de chaleur Download PDF

Info

Publication number
WO2013024201A1
WO2013024201A1 PCT/FI2012/050775 FI2012050775W WO2013024201A1 WO 2013024201 A1 WO2013024201 A1 WO 2013024201A1 FI 2012050775 W FI2012050775 W FI 2012050775W WO 2013024201 A1 WO2013024201 A1 WO 2013024201A1
Authority
WO
WIPO (PCT)
Prior art keywords
fluidized bed
heat exchanger
exchanger pipe
pipe
dimension
Prior art date
Application number
PCT/FI2012/050775
Other languages
English (en)
Inventor
Mikko Varonen
Original Assignee
Metso Power Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Metso Power Oy filed Critical Metso Power Oy
Publication of WO2013024201A1 publication Critical patent/WO2013024201A1/fr

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F22—STEAM GENERATION
    • F22B—METHODS OF STEAM GENERATION; STEAM BOILERS
    • F22B31/00—Modifications of boiler construction, or of tube systems, dependent on installation of combustion apparatus; Arrangements of dispositions of combustion apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00—Fluidised bed combustion apparatus
    • F23C10/02—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed
    • F23C10/12—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated exclusively within the combustion zone
    • F23C10/14—Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated exclusively within the combustion zone the circulating movement being promoted by inducing differing degrees of fluidisation in different parts of the bed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D13/00—Heat-exchange apparatus using a fluidised bed
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/02—Tubular elements of cross-section which is non-circular
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/14—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2206/00—Fluidised bed combustion

Definitions

  • the invention relates to the use of a heat exchanger pipe in a fluidized bed.
  • the invention also relates to the use of a heat exchanger in a fluidized bed, the heat exchanger comprising said heat exchanger pipe.
  • the invention also relates to the use of a heat exchanger pipe in a fluidized bed boiler.
  • the invention also relates to a fluidized bed reactor comprising said heat exchanger pipe.
  • the invention also relates to a fluidized bed boiler comprising said fluidized bed reactor.
  • the invention also relates to a method for heating a heat transfer fluid with granular solid substance. Background of the invention
  • a fluidized layer refers to a layer formed by a solid and granular substance, where the grains of the solid substance are in a fluidized state.
  • the fluidized state can be achieved, for example, by fluidizing the grains by means of a fluidizing gas flow.
  • the fluidized layer is formed in a fluidized bed reactor, which has been or is supplied with said granular solid substance.
  • the fluidized bed reactor can be supplied with fluidizing gases from below, for fluidizing the solid substance.
  • the fluidized layer can also be called a fluidized bed. Chemical reactions, such as burning or cracking of hydrocarbons, or physical reactions, such as cooling of solid substance, can take place in a fluidized bed reactor.
  • a fluidized bed is the cooling of a solid substance. It is known to cool a hot solid granular substance in a fluidized bed in a fluidized bed reactor.
  • the solid substance can comprise, for example, coke.
  • the solid substance cools efficiently, when it is fluidized by a cooler fluidizing gas. Heat transfer to the fluidizing gas is very effective. Heat exchangers can be used to recover heat from the fluidizing gas. It would also be possible to recover heat by a heat exchanger from the fluidized bed.
  • Another application of the fluidized bed is a fluidized bed boiler.
  • the fluidized bed boiler comprises a fluidized bed reactor in which combustible material is burnt.
  • said solid substance comprises combustible material and non-combustible material, i.e. bed material, such as for example sand.
  • bed material such as for example sand.
  • the fluidized bed is formed of both combustible material and bed material by fluidizing with a fluidizing gas.
  • the fluidiz- ing gas of the fluidized bed boiler comprises oxygen. Heat formed in the combustion is effectively transferred to the bed material. From the bed material, heat can be recovered by a heat exchanger which typically comprises heat exchanger pipes.
  • the heat exchanger can be placed in the fluidized bed, or the heat exchanger can be used to recover heat from the fluidizing gas.
  • the fluidized bed boiler can also comprise a second fluidized bed reactor, in whose fluidized bed the solid substance cools down or is cooled down.
  • a second fluidized bed reactor in whose fluidized bed the solid substance cools down or is cooled down.
  • the heat transfer can be enhanced particularly on top of or below, or both on top of and below the heat exchanger pipe.
  • the heat transfer coefficient around the pipe is, on one hand, more constant and, on the other hand, higher than in the solution of prior art. It has been found that low heat transfer on top of the pipe may be due to a heap of solid substance being formed on top of the heat exchanger pipe, reducing heat transfer from the fluidized bed to the heat exchanger pipe. It has been found that low heat transfer on top of the pipe may be due to a cushion of fluidizing gas being formed below the heat exchanger pipe, reducing heat transfer from the fluidized bed to the heat exchanger pipe.
  • heat exchanger pipe in such a way that it reduces the formation of said heap of solid substance and said cushion of fluidizing gas.
  • a formation can be implemented, for example, fin structures of the heat exchanger pipe, extending in the direction of the flow of fluidizing gas and in the opposite direction, that is, in vertical directions.
  • Said heat exchanger pipe can be placed at least partly in the fluidized bed, for example in a fluidized bed boiler.
  • Fig. 1 b shows a circulating fluidized bed boiler
  • Fig. 1 c shows a circulating fluidized bed boiler
  • Fig. 1d shows a heat exchanger in a fluidized bed
  • Fig. 1 e shows heat exchanger pipes of a heat exchanger according to
  • Figure 1 a shows a fluidized bed reactor 110 provided with a fluidized bed 100.
  • the fluidized bed 100 is delimited by walls 115 and the bottom 108 of the fluidized bed reactor 1 10.
  • the fluidized bed 100 is supplied with fluidizing gas 105 through the bottom 108, wherein the solid and granular material in the fluidized bed is in a fluidized state.
  • the fluidized bed reactor 110 can be, for example, a bubbling fluidized bed boiler (BFB boiler), wherein the fluid- ized bed 100 comprises combustible material and non-combustible bed material, and the fluidizing gas 105 comprises oxygen. Heat can be recovered by a heat exchanger from the fluidized bed 100 of the bubbling fluidized bed boiler.
  • BFB boiler bubbling fluidized bed boiler
  • Figure 1 b shows a circulating fluidized bed boiler (CFB boiler) 120.
  • the furnace 130 is limited on the sides by the walls 125 of the fluidized bed boiler.
  • the furnace 130 is a fluidized bed reactor of the fluidized bed boiler. From below, the furnace 130 is limited by a grate 128.
  • the furnace of the fluidized bed boiler contains non-combustible solid bed material, such as sand, and combustible material, such as wood-based biomass.
  • the solid substance in the boiler comprises bed material and combustible material.
  • Air is supplied through the grate 128 to the furnace, which is shown by an arrow 126.
  • the solid substance is fluidized and circulated, and the combustible material mixed in the bed material is burnt.
  • the quantity of air to be supplied is so high that the bed material and the material to be burnt rise upwards in the furnace 130.
  • the circulation of the bed material and the fluidizing gas is indicated with an arrow 132.
  • Fluidizing gas can be removed from the boiler, which is indicated with an arrow 138.
  • solid substance is separated from flue gases.
  • the solid substance may comprise burnt material, that is ash and impurities, such as metal and rocks.
  • Solid substance is returned via a first chamber 136, a gas trap 137 and a second chamber 139 to the furnace 130.
  • the circulation of the solid substance is indicated with arrows 134.
  • the solid substance is in a fluidized state, among other things, in the furnace 130, in the first chamber 136, and in the second chamber 139.
  • heat can be recovered from the fluidized bed by a heat exchanger which can be placed, for example, in the furnace 130, in the chamber 136, or in the chamber 139.
  • the fluidized bed reactor refers to the space where the fluidized bed forms or is formed. Chemical reactions, such as combustion, take place in the furnace 130, and cooling of the solid substance takes place in the chambers 136, 139.
  • Said first chamber 136 or second chamber 139 can thus be the second fluidized bed reactor of the circulating fluidized bed boiler 120.
  • Fluidizing gas is entrained in the solid substance entering the chamber 136 from the cyclone 135.
  • the solid substance is in a fluidized state in the chamber 136, and the direction of the flow of the solid substance 136 is substantially downwards.
  • the solid substance is fluidized by means of fluidizing gas (not shown in the figure) introduced to the bottom of said chamber.
  • the solid substance in the gas trap 137 is also in a fluidized state.
  • the function of the gas trap 137 is to provide a pressure difference between its inlet and outlet sides, that is, between the first chamber 136 and the second chamber 139.
  • solid substance is cooled in the fluidized bed which is arranged in a third chamber 133.
  • Said third chamber 133 may thus be a fluidized bed reactor of the cir- culating fluidized bed boiler 120.
  • the flow of solid substance 134 is divided into two fractions 134a and 134b in the gas trap.
  • the fraction 134a is directed, as shown in Fig. 1 c, via the gas trap, particularly its outlet side, to the furnace 130.
  • the fraction 134b is directed from the gas trap to a separate heat exchanger for the solid substance.
  • Said heat exchanger for the solid substance comprises said third chamber 133.
  • the fraction 134b is returned to the furnace 130, as illustrated in Fig. 1 c.
  • the solid substance can be kept in a fluidized state by supplying fluidizing gas (not shown in the figure) into the heat exchanger for the solid substance.
  • the solid substance flows substantially from above downwards and is in a fluidized state.
  • Figure 1d shows a heat exchanger 140 in a fluidized bed 145.
  • the fluidized bed 145 is in a fluidized bed reactor.
  • the fluidized bed 145 can be, for exam- pie, in a fluidized bed boiler.
  • the fluidized bed can be, for example, in a circulating fluidized bed boiler, in the furnace 130 of the circulating fluidized bed boiler, wherein the direction of flow of the fluidized bed is substantially from below upwards.
  • the fluidized bed can be, for example, in a circulating fluidized bed boiler, in a chamber 136 in connection with the inlet side of a gas trap in the circulating fluidized bed boiler, wherein the direction of flow of the solid substance is substantially from above downwards.
  • FIG. 1 e shows the internal structure of a heat exchanger.
  • the heat exchanger comprises heat exchanger pipes 150 with a circular cross-section.
  • the heat exchanger is arranged in a fluidized bed 145.
  • the direction 160 of flow of the fluidizing gas can be from below upwards.
  • the heat exchanger can be arranged in a fluidized bed in which the direction 162 of flow of solid substance can be from above downwards.
  • the direction of flow of both the fluidizing gas and the solid substance can be from below upwards.
  • the direc- tion of flowing of the fluidizing gas or the solid substance is substantially vertical.
  • the heat exchanger pipe 150 comprises a surface that encloses the inner part of the heat exchanger pipe.
  • the heat exchanger pipe has a profile extending in its longitudinal direction.
  • the inner part of the heat exchanger pipe is configured to transfer a heat transfer fluid through the heat exchanger, wherein the surface of the heat exchanger pipe is not permeable to the heat transfer fluid. Consequently, the surface of the heat exchanger pipe is leak- proof.
  • the heat exchanger pipe 150 of the heat exchanger is placed in a fluidized bed in such a way that said profile is substantially horizontal.
  • the profile of the heat exchanger pipe is substantially transverse to a direction of flow of the fluidized bed.
  • the heat exchanger pipes may also extend outside the fluidized bed 145, wherein at least part of the heat exchanger pipe 150 is placed in the fluidized bed 145.
  • FIG. 2 shows some heat exchanger pipes 150 in a fluidized bed 145.
  • the heat exchanger pipes are intermeshed with each other in the verti- cal direction.
  • the heat exchanger pipes could be vertically aligned to each other, as shown in Fig. 1d.
  • the fluidized bed 100 is fluidized by fluidizing gases 160, whose direction of flow is substantially from below upwards. It is obvious that when flowing past the heat exchanger pipe 150, the fluidizing gas circumvents the heat exchanger pipe 150.
  • the direction of the flu- idizing gas flowing past the pipes varies locally, which is illustrated by an arrow 161 drawn with a broken line.
  • an area 210 is formed underneath the heat exchanger pipe, where the flow of the fluidizing gas is substantially reduced.
  • turbulence 220 is formed in the flow above the heat exchanger pipe. It has been found that a cushion 215 of fluidizing gas is formed underneath the heat exchanger pipe in the fluidized bed. In the cushion 215 of fluidizing gas, the flow of fluidizing gas is low, wherein the cushion 215 of fluidizing gas can act as a thermal insulation from the fluidized bed 45 to the heat exchanger pipe 150. It has also been found that a heap 225 of solid substance is formed above the heat exchanger pipe in the fluidized bed.
  • the flow (turnover) of fluidizing gas is low, wherein the heap 225 of solid substance can act as a thermal insulation from the fluidized bed 145 to the heat exchanger pipe 150.
  • the formation of the cushion 215 of fluidizing gas or the heap 225 of solid substance may be due to the guidance of the flow by the heat exchanger pipe 150.
  • the direction of flowing is substantially vertical.
  • the heat exchanger pipe can be substantially horizontal or at another angle to the horizontal plane.
  • the heap 225 of solid substance can also be formed underneath the heat exchanger pipes.
  • the cush- ion 215 of fluidizing gas can be formed above the heat exchanger pipe.
  • the size of the cushion 215 of fluidizing gas and the heap 225 of solid substance formed can be affected by the flow rate. When the flow rate increases, said heat transfer coefficient increases. A high flow rate, however, increases the wear of the heat exchanger pipe and thereby reduces its service life.
  • the heat exchanger pipe 300 comprises a surface that encloses the inner part of the heat exchanger pipe.
  • the heat exchanger pipe 300 has a substantially continuous profile shape in its longitudinal direction transverse to its cross-sectional plane.
  • the inner part of the heat exchanger pipe is configured to transfer a heat transfer fluid through the heat exchanger pipe, wherein the surface of the heat exchanger pipe is not permeable to the heat transfer fluid. Consequently, the surface of the heat exchanger pipe is leak-proof.
  • the lower fin 312 of the heat exchanger pipe 300 significantly reduces the size of the cushion 215 of fluidizing gas formed.
  • the height of the lower fin 312 of the heat exchanger pipe 300 can be greater than the thickness of a typical cushion 2 5 of fluidizing gas, as shown in Fig. 3.
  • the upper fin 314 of the heat exchanger pipe 300 significantly reduces the size of the heap 225 of solid substance formed.
  • the height of the upper fin 314 of the heat exchanger pipe 300 can be greater than the height of a typical heap 225 of solid substance, as shown in Fig. 3.
  • at least part of the fin 314 penetrates through the heap 225 of solid substance.
  • the heat exchanger pipe 300 which comprises the fin 314, is in direct contact with the fluidized bed 145, wherein the heat transfer from the fluidized bed 145 via the fin 314 to the heat exchanger pipe 300 is good.
  • the fin 314 of the heat exchanger pipe comprises a material of high thermal conductivity, wherein the heat transfer from the fluidized bed 145 to the pipe 150 and to the heat transfer fluid flowing inside the pipe 150 is also enhanced.
  • the fin 314 can consist of a metal.
  • the fin 314 is connected to the pipe 150 by a thermally conductive joint.
  • the fin 314 can be connected to the pipe 150 by, for example, welding.
  • the lower fin 312 reduces the size of the heap 225 of solid substance and the upper fin 314 reduces the size of the cushion 225 of fluidizing gas.
  • FIG. 4a shows a cross-section of the heat exchanger pipe according to Fig. 3 in more detail.
  • the heat exchanger pipe 300 comprises a pipe 150 with a substantially circular cross-section.
  • the ratio of the height hi of the upper fin 314 of the pipe (Fig. 4a) to the diameter d of the pipe can thus be at least 1/2.
  • the ratio of the height h 2 of the lower fin 312 of the pipe (Fig. 4a) to the diameter d o ⁇ the pipe can be at least 1/2, correspondingly.
  • it may be advantageous to make the upper fins 314 and the lower fins 312 equally high, wherein h 1 h 2 .
  • hi h 2 ⁇ d/2, correspondingly. Because the fins diminish both the heap of solid substance and the cushion of fluidizing gas, slightly lower fins have also been found to enhance the heat transfer.
  • the thickness of the fin is significant for thermal conductivity, because a thick fin conducts heat better than a thin one. On the other hand, the manufacturing cost of a thick fin is higher than that of a thin fin.
  • the thickness of the fin can be, for example, 3 to 15 mm.
  • the heat exchanger pipe 300 tapers towards its upper and lower edges, which edges are determined by said first dimension of the heat exchanger pipe.
  • said first dimension is placed between the upper edge and the lower edge of the cross-sectional plane of the heat exchanger pipe.
  • the horizontal width of the cross-section of the heat exchanger pipe 300 becomes smaller from the centre of the heat exchanger pipe 300 towards the upper or lower edge of the heat exchanger pipe.
  • FIG. 4c shows a third embodiment of the heat exchanger pipe 300.
  • the heat exchanger pipe 300 comprises a pipe 150 with a substantially circular cross-section.
  • the pipe 150 comprises a surface that encloses an inner part.
  • the inner part of the pipe 150 is configured to transfer heat transfer fluid through the pipe 150, wherein the surface of the pipe 150 is not permeable to the heat transfer fluid. Consequently, the surface of the pipe is leak-proof.
  • the diameter of the pipe 150 is d.
  • the heat exchanger pipe 300 of Fig. 4c also comprises an upper fin 314 and a lower fin 312.
  • the fins 312, 314 are welded to the pipe 150 by welded joints 400.
  • the welded joints 400 increase the contact area between the fins and the pipe 150, thereby increasing the heat transfer between the fins and the pipe.
  • said fins are substantially circular in cross- section.
  • the fins 312, 314 and the pipe 150 have a substantially parallel lon- gitudinal direction.
  • the fin 312, 314 comprises a surface that encloses an inner part. Said fins can be hollow or solid. If the fin is hollow, the fin is also configured to transfer heat transfer fluid through the heat transfer pipe, wherein the surface of the fin is not permeable to the heat transfer fluid. Consequently, the surface of the fin is leak-proof.
  • the diameter of the upper fin is di and the diameter of the lower fin is afe. The diameters can be equal.
  • the heat exchanger pipe 300 of Fig. 4c comprises a surface that encloses the inner part of the heat exchanger pipe 300.
  • the inner part of the heat exchanger pipe 300 is divided into three compartments: the inner part of the pipe 150, and the inner parts of the fins 3 2, 314, of which each inner part can be configured to transfer heat transfer fluid through the heat exchanger pipe 300.
  • the inner part of the heat exchanger pipe 300 can be divided into two or four or more compartments as well.
  • each compartment is configured to transfer heat transfer fluid through the heat exchanger pipe.
  • at least one compartment is configured to transfer heat transfer fluid through the heat exchanger pipe.
  • a first dimension of the heat exchanger pipe 300 of Fig. 4c in its cross-sectional plane is d + di + d ⁇ .
  • a second dimension of the heat exchanger pipe in the direction of the cross-sectional plane transverse to the first dimension is d.
  • its second dimension is the substantially horizontal dimension of the cross-sectional plane of the heat exchanger pipe 300.
  • the first dimension is greater than the second dimension, and the heat exchanger pipe is tapered towards its upper and lower edges, which edges are determined by said first dimension of the heat exchanger pipe.
  • the horizontal width of the cross-section of the heat exchanger pipe 300 reduces towards the upper or lower edge of the heat exchanger pipe.
  • the width of the heat exchanger pipe 300 does not necessarily decrease continuously from the central area of the heat exchanger pipe 300 towards the upper or lower edge of the heat exchanger pipe, but at some points, the width may increase.
  • Figure 4d shows a fourth embodiment of the heat exchanger pipe 300.
  • the cross-section of the heat exchanger pipe 300 of Fig. 4d is a parallelogram with rounded corners.
  • the radii of curvature of the upper and lower corners are substantially equal.
  • the radii of curvature of both side corners are substantially equal.
  • the radius of curvature of the upper corner is smaller than the radius of curvature of the side corner.
  • a first dimension of such a heat exchanger pipe in its cross-sectional plane is d mx .
  • a second dimension of the heat exchanger pipe in the direction of the cross-sectional plane transverse to the first dimension is d mn .
  • d mx > d mn -
  • the heat exchanger pipe is tapered towards its upper and lower edges.
  • the dimension of the cross- section of the heat exchanger pipe 300 transverse to the flowing direction decreases towards the upper or lower edge of the heat exchanger pipe.
  • the heat exchanger pipe 300 can also have an elliptical ⁇ i.e. oval) cross-section.
  • the ellipse has first and second dimensions corresponding to the axes of the ellipse.
  • the first dimension can be selected to be greater than the second dimension (unless the ellipse is circular).
  • said second dimension can be substantially horizontal.
  • the dimension of the cross-section of the heat exchanger pipe 300 transverse to the flowing direction decreases towards the upper or lower edge of the heat exchanger pipe.
  • the heat exchanger pipe is used for recovering heat.
  • the heat exchanger pipe 300 is advantageously made of a material with good thermal conductivity. In use, heat can be recovered from a very hot material. For example, the temperature of solid material in a fluidized bed boiler can be about 800 ⁇ .
  • the heat exchanger pipe 300 is a dvantageously made of a material with good heat stability.
  • the heat exchanger pipe 300 can be made of a material comprising a metal.
  • the heat exchanger pipe 300 can consist of a metal. If the heat exchanger pipe 300 comprises fins 312, 314 and a pipe 150, the fins 312, 314 can comprise the same metal as the pipe 150, or a different metal.
  • the heat exchanger pipe 300 has a first dimension d max in its cross-sectional plane.
  • the first dimension is one of the following: d + h 1 + h 2 , d + di + d ⁇ , and d mx .
  • the heat exchanger pipe 300 has a second dimension d mm in the horizontal direction transverse to the first direction.
  • said dimension dmin is one of the following: d and d mn .
  • the first dimension d max is greater than said second dimension dmn transverse to this.
  • the smaller of said dimensions is placed horizontally.
  • the horizontal dimen- sion dmin of the heat exchanger pipe 300 is smaller than the first dimension dmax-
  • the horizontal width of the cross-section of the heat exchanger pipe 300 decreases towards the upper or lower edge of the heat exchanger pipe.
  • the upper and lower edges of the heat exchanger pipe are determined by said first dimension.
  • the radius of curvature of the lower part of the heat exchanger pipe 300 is also smaller than the radius of curvature of the side part of the heat exchanger pipe 300.
  • the lower part can comprise a fin 312 with a small radius of curvature.
  • the radius of curvature of the upper part of the heat exchanger pipe 300 is smaller than the radius of curvature of the side part of the heat exchanger pipe 300.
  • the upper part can comprise a fin 314 with a small radius of curvature.
  • the inner part of the heat exchanger pipe 300 can be divided to compartments. In an embodiment, each compartment is configured to transfer heat transfer fluid through the heat exchanger pipe. In an embodiment, at least one compartment is configured to transfer heat transfer fluid through the heat exchanger pipe. If the inner part of the heat exchanger pipe 300 is not divided, the inner part constitutes an enclosure configured to transfer heat transfer fluid through the heat exchanger pipe. Particularly when used in a fluidized bed, the above-presented heat exchanger pipes 300 have the above-described technical advantage: the heat exchanger pipe 300 eliminates or diminishes at least one of the following: the cushion 215 of fluidizing gas and the heap 225 of solid substance. Thus, the heat transfer coefficient increases from the fluidized bed to the heat exchanger pipe 300.
  • the fins 312, 314 enhance the heat transfer from the fluidized bed to the heat transfer fluid flowing in the heat exchanger pipe, because the fins 312, 314 increase the surface area of the heat exchanger pipe.
  • the heat transfer coefficient between the heat exchanger pipe 300 and the heat transfer fluid flowing inside the same is not necessarily changed.
  • the fluidized bed can be placed in a fluidized bed reactor for forming the fluidized bed.
  • Said fluidized bed reactor can comprise a heat exchanger comprising a heat exchanger pipe 300.
  • Said fluidized bed reactor can be a part of a fluidized bed boiler.
  • the fluidized bed can be placed in one of the following:
  • the fluidized bed can also be placed in a fluidized bed reactor used for cool- ing solid substance.
  • the above-presented heat exchanger pipe 300 and its use in a fluidized bed increases the heat transfer from the fluidized bed to the heat exchanger pipe 300 and further to the heat transfer fluid flowing in the pipe.
  • a fluidized bed reactor such as a fluidized bed boiler, is used to achieve a given heat output transferred to the heat transfer fluid.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Thermal Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Geometry (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Fluidized-Bed Combustion And Resonant Combustion (AREA)

Abstract

L'invention concerne l'utilisation d'une conduite d'échangeur de chaleur (300) dans le lit fluidisé d'une chaudière à lit fluidisé. La conduite d'échangeur de chaleur (300) présente une première dimension (dmax) dans son plan de section transversale et une seconde dimension (dmin) dans une direction transversale à la première dimension, la première dimension étant supérieure à la seconde dimension. Au moins une partie de la conduite d'échangeur de chaleur (300) est placée dans un lit fluidisé (100, 136, 133, 139, 130, 145) de sorte que la direction longitudinale de la conduite forme un angle inférieur à 60 degrés avec le plan horizontal. Ladite seconde dimension (dmjn) est horizontale. La section transversale de la conduite d'échangeur de chaleur (300) se termine en pointe en direction des bords supérieur et inférieur. L'invention concerne en outre une chaudière à lit fluidisé permettant la mise en œuvre de ladite utilisation. L'invention concerne en outre un procédé permettant de chauffer un fluide de transfert de chaleur au moyen d'une substance solide granuleuse. Dans le procédé, un lit fluidisé est formé de ladite substance solide dans la chaudière à lit fluidisé et la conduite d'échangeur de chaleur est utilisée de la manière décrite.
PCT/FI2012/050775 2011-08-15 2012-08-08 Amélioration d'un transfert de chaleur d'un lit fluidisé vers une conduite d'échangeur de chaleur WO2013024201A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI20115798A FI20115798L (fi) 2011-08-15 2011-08-15 Lämmönsiirron parantaminen leijukerroksesta lämmönvaihdinputkeen
FI20115798 2011-08-15

Publications (1)

Publication Number Publication Date
WO2013024201A1 true WO2013024201A1 (fr) 2013-02-21

Family

ID=44515432

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2012/050775 WO2013024201A1 (fr) 2011-08-15 2012-08-08 Amélioration d'un transfert de chaleur d'un lit fluidisé vers une conduite d'échangeur de chaleur

Country Status (2)

Country Link
FI (1) FI20115798L (fr)
WO (1) WO2013024201A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101876547B1 (ko) * 2017-01-13 2018-07-09 정이영 성에제거기능을 지닌 냉동파이프
JP2019516942A (ja) * 2016-05-25 2019-06-20 ノヴァ ケミカルズ（アンテルナショナル）ソシエテ アノニム 炉のコイルの改造フィン

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3550922A (en) * 1967-03-04 1970-12-29 Huettenwerk Oberhausen Ag Fluidized bed for controlled heat treatment
US4270599A (en) * 1978-09-29 1981-06-02 Foster Wheeler Energy Corporation Tube support structure for a fluidized bed heat exchanger
US4466479A (en) * 1982-08-19 1984-08-21 Texaco Inc. Method of transferring heat between two fluids and heat exchange tube
DE3828646A1 (de) * 1988-08-24 1990-03-01 Steinmueller Gmbh L & C Heizflaeche zum auskoppeln von waerme aus einem mit feststoffpartikeln beladenen fluidstrom

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3550922A (en) * 1967-03-04 1970-12-29 Huettenwerk Oberhausen Ag Fluidized bed for controlled heat treatment
US4270599A (en) * 1978-09-29 1981-06-02 Foster Wheeler Energy Corporation Tube support structure for a fluidized bed heat exchanger
US4466479A (en) * 1982-08-19 1984-08-21 Texaco Inc. Method of transferring heat between two fluids and heat exchange tube
DE3828646A1 (de) * 1988-08-24 1990-03-01 Steinmueller Gmbh L & C Heizflaeche zum auskoppeln von waerme aus einem mit feststoffpartikeln beladenen fluidstrom

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2019516942A (ja) * 2016-05-25 2019-06-20 ノヴァ ケミカルズ（アンテルナショナル）ソシエテ アノニム 炉のコイルの改造フィン
KR101876547B1 (ko) * 2017-01-13 2018-07-09 정이영 성에제거기능을 지닌 냉동파이프

Also Published As

Publication number Publication date
FI20115798L (fi) 2013-02-16
FI20115798A0 (fi) 2011-08-15

Similar Documents

Publication Publication Date Title
US8684070B2 (en) Compact radial platen arrangement for radiant syngas cooler
RU2232939C2 (ru) Реактор с циркулирующим псевдоожиженным слоем
EP1954923B1 (fr) Unite de refroidissement de gaz de synthese par rayonnement
RU2119119C1 (ru) Реактор с циркулирующим псевдоожиженным слоем
WO2017088742A1 (fr) Écran d'eau d'une chaudière supercritique à lit fluidisé circulant présentant une grande stabilité d'écoulement à faible charge, et procédé d'obtention d'un faible débit massique
JPS5823521B2 (ja) 斜めに延長させた熱交換管を備えた流動床式熱交換器
JP6255011B2 (ja) 流動層ボイラの層内伝熱管及び流動層ボイラ
US10890323B2 (en) Circulating fluidized bed boiler with a loopseal heat exchanger
JPH0313482B2 (fr)
EP2668444B1 (fr) Procédé d'amélioration du fonctionnement d'un réacteur à masse circulante et réacteur permettant de mettre en oeuvre un tel procédé
RU2537482C2 (ru) Циркулирующий псевдоожиженный слой с соплами для подачи вторичного воздуха в топочную камеру
AU2009297366B2 (en) Boiler furnace for a power station
WO2013024201A1 (fr) Amélioration d'un transfert de chaleur d'un lit fluidisé vers une conduite d'échangeur de chaleur
KR20200101356A (ko) 루프시일 열 교환기를 갖춘 순환식 유동층 보일러
CN210179588U (zh) 超临界二氧化碳塔式锅炉炉墙受热面布置结构
JP5748784B2 (ja) 流動層反応器装置
RU2599888C1 (ru) Теплообменник с псевдоожиженным слоем
CA2585610C (fr) Chaudiere a lit fluidise et element de grille associe
JP4463825B2 (ja) 貫流ボイラ
US20070266915A1 (en) Partition wall structure of a furnace
JPH0235889B2 (fr)
JPS61231301A (ja) 貫流ボイラ
EP3597996B1 (fr) Chaudière à lit fluidisé à circulation de type chute de sable fluide avec une pluralité de colonnes montantes et son procédé de fonctionnement
CN202561731U (zh) 一种紧凑型循环流化床锅炉
JPS62258912A (ja) 流動床燃焼炉

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 12759789

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 12759789

Country of ref document: EP

Kind code of ref document: A1