DESC:FIELD OF DISCLOSURE
The present disclosure relates to a hybrid boiler system. More particularly, the present disclosure relates to a packaged hybrid boiler system which provides flexibility of fuel.
DEFINITION
MEMBRANE PANEL herein refers to a plurality of tubes connected to each other by a plurality of fins, thus forming a continuous membrane like structure that has an alternate arrangement of tubes and fins.
BACKGROUND
A boiler system is a system for heating and vaporizing a fluid for using the vaporized fluid in some other application. Boiler systems are generally classified as integral furnace boiler systems and hybrid boiler systems. In an integral furnace boiler system, the furnace is placed inside the boiler shell. The boiler typically works on fuels like coal, wood logs, and biomass briquettes. Due to the placement of the furnace within the boiler shell, this type of boiler system offers inherent limitations to the furnace dimensions. As the furnace dimensions cannot be increased beyond certain limits, the combustion performance of such a boiler system is low. Other disadvantages of the integral furnace boiler system are poor volatile combustion and poor residence time of the solid /biomass fuels in the furnaces having smaller volumes, thereby giving poor efficiency and high emissions. Further, the types of combustors that can be used in the integral furnace boiler systems are limited to a stationary grate, a bubbling bed, or a chain grate combustor. Other combustors such as reciprocating grate, moving grate, and fluidized bed cannot be placed inside the integral furnace boiler system. This results in limited flexibility of fuel.
To overcome the above-noted limitations of the integral furnace boiler system, a hybrid boiler system can be used. In the hybrid boiler system, the furnace is placed outside the boiler shell, surrounded by water walls (membrane panel). The boiler shell is placed at the top end of the membrane panel. The boiler system comprises both water tubes and fire tubes, thus it is called a hybrid boiler system. A major drawback of the hybrid boiler system is that such boiler systems cannot be packaged because of the configuration of the components such as membrane panel, boiler shell, combustors, and supporting structure, and all these components have to be assembled on-site. Also, the overall footprint for the hybrid boiler system is high. Further, to accommodate different types of combustors, the design of the membrane panel needs to be adapted.
There is therefore felt a need for a hybrid boiler system which will overcome the above-cited shortcomings of the known hybrid boiler systems.
SUMMARY
A hybrid boiler system comprising a base, a furnace chamber disposed on the base, and an internal reversal chamber also disposed on the base. The furnace chamber has a first operative end and a second operative end. The furnace chamber is configured by a first top header pipe, a first bottom header pipe spaced apart from a second bottom header pipe, a first furnace membrane panel, and a second furnace membrane panel. The first furnace membrane panel configured by a plurality of tubes and fins alternately connected, the tubes of the first furnace membrane panel are connected to and in fluid communication with the first top header pipe and the first bottom header pipe. The second furnace membrane panel configured by a plurality of tubes and fins alternately connected, the tubes of the second furnace membrane panel are connected to and in fluid communication with the first top header pipe and the second bottom header pipe.
The internal reversal chamber has a first operative end and a second operative end. The internal reversal chamber is configured by a second top header pipe, a first reversal chamber membrane panel, a second reversal chamber membrane panel, and a third reversal chamber membrane panel. The first reversal chamber membrane panel is configured by a plurality of tubes and fins alternately connected; the tubes of the first reversal chamber membrane panel are connected to and in fluid communication with the second top header pipe and the first bottom header pipe. The second reversal chamber membrane panel configured by a plurality of tubes and fins alternately connected, the tubes of the second reversal chamber membrane panel are connected to and in fluid communication with the second top header pipe and the second bottom header pipe. The third reversal chamber membrane panel is configured by a plurality of tubes and fins alternately connected, the tubes of the third reversal chamber membrane panel are connected to and in fluid communication with the second top header pipe and a transverse bottom header pipe, wherein the transverse bottom header pipe is connected to and in fluid communication with the first bottom header pipe and the second bottom header pipe. The first, second, and third reversal chamber membrane panels form three barriers and a fourth open end of the internal reversal chamber is operatively juxtaposed with one of the first and second operative ends of the furnace chamber such that the internal reversal chamber and the furnace chamber are connected to and in fluid communication with each other.
The hybrid boiler system further comprises a boiler shell having a plurality of fire tubes disposed therein. The boiler shell is disposed operatively above the furnace chamber. The plurality of fire tubes are connected to and in fluid communication with the internal reversal chamber. A combustor disposed in the furnace chamber operatively above the base. A smoke chamber is configured on an operative end of the boiler shell. An outlet is configured on the boiler shell for discharging the vaporized fluid.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure to provide a packaged hybrid boiler system which provides flexibility of fuel by allowing use of different combustors.
Another object of the present disclosure is to provide a packaged hybrid boiler system which has a smaller footprint.
Still another object of the present disclosure is to provide a packaged hybrid boiler system which gives a higher overall efficiency.
These and other objects of the present disclosure will be more apparent from the following description.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
The disclosure will now be described with the help of the accompanying drawings, in which,
FIGURE 1 illustrates a schematic of a conventional integral furnace boiler system;
FIGURE 2 illustrates a schematic of a conventional hybrid boiler system;
FIGURE 3 illustrates a schematic of the sectional-view of the embodiment of the hybrid boiler system in accordance with the present disclosure
FIGURE 4 and FIGURE 5 illustrate schematic of the isometric view of the embodiment of the hybrid boiler system, wherein the plurality of fins are absent, in accordance with the present disclosure;
FIGURE 6 illustrates a schematic of the operative front-view of the embodiment of the hybrid boiler system in accordance with the present disclosure;
FIGURE 7 illustrates a schematic of the operative rear-view of the embodiment of the hybrid boiler system in accordance with the present disclosure;
FIGURE 8 and FIGURE 9 illustrate a schematic of the side-views of an embodiment of the hybrid boiler system in accordance with the present disclosure;
FIGURE 10 and FIGURE 11 illustrate a schematic of the operative top view and operative bottom view of the embodiment of the hybrid boiler system in accordance with the present disclosure, respectively;
FIGURE 12 illustrates an isometric view of another embodiment of the hybrid boiler system in accordance with the present disclosure;
FIGURE 13 illustrates an isometric view of still another embodiment of the hybrid boiler system in accordance with the present disclosure;
FIGURE 14 illustrates an isometric view of still another embodiment of the hybrid boiler system with a bubbling bed combustor, in accordance with the present disclosure;
FIGURE 15 illustrates an isometric view of still another embodiment of the hybrid boiler system with a chain grate combustor, in accordance with the present disclosure;
FIGURE 16 illustrates an isometric view of still another embodiment of the hybrid boiler system with a reciprocating grate combustor, in accordance with the present disclosure; and
FIGURE 17 illustrates an isometric view of still another embodiment of the hybrid boiler system with a fluidized bed combustor, in accordance with the present disclosure.
DESCRIPTION OF THE ACCOMPANYING DRAWINGS
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of the ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The description herein after, of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
Referring to FIGURE 1 of the accompanying drawings, therein is disclosed a schematic of a conventional integral furnace boiler system. The boiler system is generally referenced in the FIGURE 1 by numeral 10. The boiler system 10 includes a fire door 11, an integral furnace 12, an internal reversal chamber 13, a first set of fire tubes 14, a second set of fire tubes 15, a combustor 16, a boiler shell 17, an external reversal chamber 18, and a smoke chamber 19. The furnace 12 is placed inside the boiler shell 17. The flue gases generated in the furnace 12 are conveyed to the first set of fire tubes 14 via the internal reversal chamber 13. The flue gases are then carried to the second set of fire tubes 15 from the first set of fire tubes 14 via the external reversal chamber 18. The cooled flue gases are discharged through the smoke chamber 19. The boiler system 10 has several limitations like low combustion volume, poor residence time, poor volatile combustion, poor overall efficiency, and high emissions. Also, the boiler system 10 can only be used with limited types of combustors 16.
A conventional hybrid boiler system is configured to overcome the above-cited drawbacks of a conventional integral furnace boiler system 10. FIGURE 2 of the accompanying drawings illustrates a typical hybrid boiler system; where the hybrid boiler system is referenced in the FIGURE 2 by numeral 20. The hybrid boiler system 20 includes a membrane panel 21, boiler shell 22, fire tubes 23, combustor 24, smoke chamber 25, and supporting structure 26. The furnace (not shown in the FIGURE) is placed outside the boiler shell 22, and is surrounded by the membrane panel 21. The boiler shell 22 is placed in line with the membrane panel 21 at the operative end of the membrane panel 21. The boiler shell 22 is supported on the structure 26. The membrane panel 21 is made of a plurality of tubes through which boiler water is circulated to absorb the heat generated in the furnace. The flue gases are then conveyed through the fire tubes 23 placed inside the boiler shell 22. The flue gases are discharged through the smoke chamber 25. The hybrid boiler system 20 is can be worked with different types of combustors. However, due to the configuration of the different components, the hybrid boiler system 20 cannot be packaged, thereby occupying a larger footprint. Also, the design of the membrane panel 21 must be adapted according to the type of the combustor 24.
These drawbacks of a typical hybrid boiler system 20 are overcome by the present disclosure. The present disclosure envisages a packaged hybrid boiler system in which the membrane panel and the boiler shell are selectively arranged to provide a flexibility of fuel and multiple combustors, smaller footprint, and higher overall efficiency.
The hybrid boiler system 100 will now be described with reference to Figures 3 to 7. The hybrid boiler system 100 of the present embodiment comprises a base 113, a first bottom header pipe 105A spaced apart from a second bottom header pipe 105B and both the bottom header pipes 105A, 105B disposed operatively above the base 113. The hybrid boiler system 100 further comprises a furnace chamber 102 having a first operative end 102C and a second operative end 102D. The furnace chamber 102 is configured by a first furnace membrane panel 102A and a second furnace membrane panel 102B. The first furnace membrane panel 102A is configured by a plurality of tubes and fins alternately connected. The plurality of tubes is connected to and in fluid communication with the first top header pipe 122A and the first bottom header pipe 105A. Similarly, the second furnace membrane panel 102B is configured by a plurality of tubes and fins alternately connected. The plurality of tubes is connected to and in fluid communication with the first top header pipe 122A and the second bottom header pipe 105B. The first furnace membrane panel 102A and the second furnace membrane panel 102B define the furnace chamber 102.
The hybrid boiler system 100 further comprises an internal reversal chamber 104. The internal reversal chamber 104 is configured by a first reversal chamber panel 104A, a second reversal chamber panel 104B, and a third reversal chamber panel 104C. The first reversal chamber membrane panel 104A is configured by a plurality of tubes and fins alternately connected. The plurality of tubes is connected to and in fluid communication with the second top header pipe 122B and first bottom header pipe 105A. Similarly, the second reversal chamber membrane panel 104B is configured by a plurality of tubes and fins alternately connected. The plurality of tubes is connected to and in fluid communication with the second top header pipe 122B and the second bottom header pipe 105B. Similarly, the third reversal chamber membrane panel 104C is configured by a plurality of tubes and fins alternately connected. The plurality of tubes is connected to and in fluid communication with the second top header pipe 122B and a transverse bottom header pipe 105C that is connected to and in fluid communication with the first and second bottom header pipes 105A, 105B. The first reversal chamber membrane panel 104A, the second reversal chamber membrane panel 104B, the third reversal chamber membrane panel 104C forming three barriers, and a fourth open end is operatively juxtaposed with either the first or second operative end 102C, 102D of the furnace chamber 102, thereby defining the internal reversal chamber 104. Thus, the furnace chamber 104 and the internal reversal chamber 104 are connected and in fluid communication with each other. The length of the plurality of tubes in the internal reversal chamber 104 is greater than the length of the plurality of tubes in the furnace chamber 102, in an operative vertical direction. In the present embodiment, although the furnace chamber 102 and the internal reversal chamber 104 have an arch shaped profile, as illustrated in Figure 7 and Figure 8, their profile is not limited to being arch shaped. Any other profile for the furnace chamber 102 and the internal reversal chamber 104 are within the ambit of the present disclosure.
The hybrid boiler system further comprises a boiler shell 106 disposed operatively above the furnace chamber 102. The boiler shell 106 is in fluid communication with the first top header pipe 122A and the second top header pipe 122B via riser conduits 109. The boiler shell 106 is also in fluid communication with the first bottom header pipe 105A and the second bottom header pipe 105B via downcomer conduits 121. The number of the riser conduits 109 and the downcomer conduits 121 may vary as per the application requirements. A first access opening 107 is also configured in the furnace chamber 102 for maintenance purposes.
FIGURE 6 illustrates a schematic of the operative front view of the embodiment of the hybrid boiler system 100. As seen in FIGURE 6, the hybrid boiler system 100 further comprises a plurality of fire tubes 110 disposed within the boiler shell 106. The plurality of fire tubes 110 is in fluid communication with the internal reversal chamber 104.
FIGURE 7 illustrates a schematic of the operative rear view of the embodiment of the hybrid boiler system 100 without the plurality of fins. A second access opening 111 for maintenance purposes is configured on the third reversal chamber panel 104C.
FIGURE 8 and FIGURE 9 illustrate a schematic of the side-views of an embodiment of the hybrid boiler system in accordance with the present disclosure. The profile of the first access opening 107 can be clearly understood with reference to FIGURE 9.
FIGURE 10 and FIGURE 11 illustrate a schematic of the operative top view and operative bottom view, of the embodiment of the hybrid boiler system 100, respectively. The entire configuration of the hybrid boiler system 100 can be better understood with reference to views depicted in FIGURE 9 and FIGURE 10.
The operative configuration of the hybrid boiler system will now be described with reference to FIGURE 3. FIGURE 3 illustrates a schematic of the sectional-view of the embodiment of the hybrid boiler system 100. As seen in FIGURE 3, the furnace chamber 102, the internal reversal chamber 104, and the boiler shell 106 are disposed operatively above the base 113. The base 113 is made of structural steel frames and supports the refractory material above it. The combustor 116 is disposed within the furnace chamber 102 operatively above the base 113. The combustor 116 can be selected from a stationary grate, a bubbling bed, a chain grate, a moving grate, a reciprocating grate, an underfeed stoker, and a fluidized bed. The hybrid boiler system 100 further comprises a plurality of baffles 118.
In an operative configuration, the fluid to be heated inside the hybrid boiler system 100 is introduced therein via the first bottom header pipe 105A and the second bottom header pipe 105B. The fluid to be heated flows from the first and second bottom header pipes 105A, 105B into the plurality of tubes disposed in the furnace membrane panels 102A, 102B and the reversal chamber membrane panels 104A, 104B, 104C. Thereafter, a fuel is burnt in the furnace chamber 102. The fuel is loaded in the furnace chamber via a fire-door 115. The fluid in the plurality of tubes of the furnace membrane panels 102A, 102B is heated by the combustion of the fuel in the furnace chamber 102. After being heated, the fluid vaporizes and rises into the first top header pipe 122A, and thereafter into the boiler shell 106 via riser conduits 109.
The combustion of fuel in the furnace chamber 102 generates flue gas. The combustion air is received through an air inlet 108. The plurality of baffles 118 changes the direction of the flue gas thus increasing the residence time of the hot flue gas inside the furnace chamber 102. The increase in the residence time of the hot flue gas inside the furnace chamber 102 results in complete combustion of fuel. Moreover, the plurality of baffles 118 also guides the flow of the flue gas in a manner indicated by arrows in FIGURE 3.
The flue gas now enters the internal reversal chamber 104. The internal reversal chamber 104 is in fluid communication with the plurality of fire tubes 110. The flue gas is now fed to the plurality of fire tubes 110 inside the boiler shell 106. The internal reversal chamber 104 is so called, as the flue gas passes from the shell side, i.e., furnace chamber 102 to the tubes side, i.e., the plurality of fire tubes 110, via the internal reversal chamber 104. At this point, the flue gas is still very hot. The fluid that has entered the boiler shell 106 via riser conduits 109 is still a mixture of fluid in vapour form and liquid form and it is further heated by the flue gas present inside the plurality of fire tubes 110. The boiler shell 106 also has a smoke chamber 112 configured thereon, adapted to discharge the flue gas. The vaporized fluid is then discharged from an outlet 123 configured on the boiler shell 106. Any fluid present in the boiler shell 106 in the liquid form is drained from the boiler shell 106 via the downcomer conduits 121. In an embodiment, thermal insulation can be provided on the furnace chamber 102 and the internal reversal chamber 104 for reducing loss of heat, contained in the flue gas, by heat transfer mechanisms.
Sheet metal covering panels can be provided to improve the aesthetics of the boiler packaging. FIGURE 12 of the accompanying drawings illustrates another embodiment of the hybrid boiler system of the present disclosure. The hybrid boiler system 200 illustrated in the FIGURE 12 comprises a stationary grate combustor and a fire door 204 for manual fuel feeding with a round paneling 202. FIGURE 13 of the accompanying drawings illustrates yet another embodiment of the hybrid boiler system of the present disclosure. The hybrid boiler system 300 illustrated in the FIGURE 13 comprises a chain grate combustor 304 with a square paneling 302.
FIGURE 14 illustrates an isometric view another embodiment of the hybrid boiler system 400 of the present disclosure. FIGURE 14 depicts a bubbling bed combustor 401 installed in the hybrid boiler system 400. The bubbling bed combustor 401 comprises an inlet opening 402 for fuel and secondary air, an access door 403 for maintenance purposes, and a plenum chamber 404.
FIGURE 15 illustrates an isometric view another embodiment of the hybrid boiler system 500 of the present disclosure. FIGURE 15 depicts a chain grate combustor 501 installed in the hybrid boiler system 500.
FIGURE 16 illustrates an isometric view of another embodiment of the hybrid boiler system 600 of the present disclosure. FIGURE 16 depicts a reciprocating grate combustor 601 installed in the hybrid boiler system 600. The reciprocating grate combustor 601 comprises a fuel feeder 602, a reciprocating grate 603, and a hydraulic power unit 604 for the reciprocating grate 603.
FIGURE 17 illustrates an isometric view of another embodiment of the hybrid boiler system 700 of the present disclosure. FIGURE 17 depicts a fluidized bed combustor 701 installed in the hybrid boiler system 700. The like components of the hybrid boiler system 700 have been referenced with identical reference numerals as used to describe FIGURES 3-9. The fluidized bed combustor 701 is disposed operatively below the furnace chamber 102 of the hybrid boiler system 700. As seen in Fig. 17, the fluidized bed combustor 701 comprises a settling chamber 730 positioned below the internal reversal chamber 104 where the flue gases reverse the direction of flow and enter the plurality of tubes 110 in the boiler shell 106. This change of direction causes the settling of carry over ash present in the flue gas into the settling chamber 730. The fluidized bed combustor 701 further comprises an in-bed bottom header pipe 731, a branch pipe 732 extending in an operative horizontal direction from the in-bed bottom header pipe 731, an in-bed coil 733 that facilitates fluid communication between the in-bed bottom header pipe 731 and an in-bed top header pipe 734. The main combustor 116 is disposed in the fluidized bed combustor 701 operatively below the in-bed coil 733. The in-bed bottom header pipe 731 supplies the fluid to be heated to the in-bed coil 733 via the branch pipe 732. The combustion of fuel takes place in the combustor 116, thereby heating the fluid present in the in-bed coil 733. The in-bed top header pipe 734 supplies a mixture of fluid in gaseous and liquid form to the furnace chamber 102. The in-bed coil 733 is placed at an inclination to facilitate the natural circulation of water. This in-bed coil 733 also helps in maintaining the bed temperature to the desired level.
An experimental analysis was conducted on an exemplary embodiment of the present disclosure. The results of the experimental analysis are tabulated as follows.
TABLE 1 illustrates the different parameters that were tested during the experimental analysis of the exemplary embodiment:
Parameter Unit Of Measurement Value
Steam flow kg/h 1800
Steam Pressure bar 28
Fuel - Wood Chips
Net Calorific Value (NCV) of fuel kcal/kg 2952
Efficiency on NCV basis % 85
Fuel firing rate kg/h 390
Excess air % 55
Furnace outlet Flue gas temperature 0C 805
Convective tube inlet Flue gas temperature 0C 740
Boiler exit Flue gas temperature 0C 277
Feed water temperature 0C 80
Pressure drop (flue gas) across boiler mm of water
column 45
Oxygen in Flue gas % 6.5
Carbon Dioxide in Flue gas % 12.5
Referring to table 1, the fuel used in this exemplary embodiment was wood chips having a calorific value of 2952 kcal/kg. The hybrid boiler system of the exemplary embodiment gives steam as an output at a rate of 1800kg/h. The pressure of the steam is 28 bar. Excess air provided for combustion was 55% more than the stoichiometric air required for combustion. The oxygen content of 6.5% and carbon dioxide content of 12.5% in the flue gas is because of the excess air supplied. The temperature of the flue gas leaving the furnace chamber is 805oC, temperature of flue gas entering the fire tubes is 740oC, and the temperature of the flue gas exiting the boiler is 277oC. The overall efficiency of the hybrid boiler system calculated on the basis of the net calorific value is 85%, which is very high.
ECONOMIC SIGNIFICANCE AND TECHNICAL ADVANCEMENT
The hybrid boiler system, as described in the present disclosure, has several technical advantages including, but not limited to, the realization of: a packaged hybrid boiler system in which the membrane panel and the boiler shell are selectively arranged to provide a flexibility of fuel and multiple combustors, smaller footprint, and higher overall efficiency.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
In view of the wide variety of embodiments to which the principles of the present disclosure can be applied, it should be understood that the illustrated embodiments are exemplary only. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principle of the disclosure. These and other modifications in the nature of the disclosure or the preferred embodiments will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation. ,CLAIMS:1. A hybrid boiler system comprising:
? a furnace chamber having a first operative end and a second operative end, said furnace chamber, said furnace chamber configured by:
? a first top header pipe;
? a first bottom header pipe spaced apart from a second bottom header pipe, said first bottom header pipe and said second bottom header pipe adapted to supply a fluid to be heated in said hybrid boiler system;
? a first furnace membrane panel configured by a plurality of tubes and fins alternately connected, said plurality of tubes of said first furnace membrane panel connected to and in fluid communication with said first top header pipe and said first bottom header pipe, said plurality of tubes adapted to receive said fluid from said first bottom header pipe and supply said fluid to said first top header pipe;
? a second furnace membrane panel configured by a plurality of tubes and fins alternately connected, said plurality of tubes adapted to receive said fluid, said tubes of said second furnace membrane panel connected to and in fluid communication with said first top header pipe and said second bottom header pipe, said plurality of tubes adapted to receive said fluid from said second bottom header pipe and supply said fluid to said first top header pipe;
? a boiler shell having a plurality of fire tubes disposed therein, said boiler shell disposed operatively above said furnace chamber;
? a combustor disposed in said furnace chamber, said combustor adapted to receive a fuel, combustion of said fuel taking place in said furnace chamber generating flue gas, said fluid in said plurality of tubes in said first furnace membrane panel and said second furnace membrane panel heated by said flue gas, thereafter said fluid vaporizes and said vaporized fluid fed to said boiler shell;
? an internal reversal chamber configured to allow passage of said flue gas from said furnace chamber into said plurality of fire tubes, said internal reversal chamber disposed adjacent to one of said first operative end and said second operative end of said furnace chamber such that said furnace chamber and said internal reversal chamber are in fluid communication with each other, said internal reversal chamber connected to and in fluid communication with said plurality of fire tubes, said vaporized fluid further heated by said plurality of fire tubes in said boiler shell;
? a smoke chamber configured on an operative end of said boiler shell for discharging said flue gas;
? an outlet configured on said boiler shell for discharging the vaporized fluid.
2. The hybrid boiler system as claimed in claim 1, wherein said internal reversal chamber comprises:
? a second top header pipe;
? a first reversal chamber membrane panel configured by a plurality of tubes and fins alternately connected, said plurality of tubes of said first reversal chamber membrane panel connected to and in fluid communication with said second top header pipe and said first bottom header pipe, said plurality of tubes adapted to receive said fluid from said first bottom header pipe and feed said fluid to said second top header pipe;
? a second reversal chamber membrane configured by a plurality of tubes and fins alternately connected, said plurality tubes of said second reversal chamber membrane panel connected to and in fluid communication with said second top header pipe and said second bottom header pipe, said plurality of tubes adapted to receive said fluid from said second bottom header pipe and feed said fluid to said second top header pipe;
? a third reversal chamber membrane panel configured by a plurality of tubes and fins alternately connected, said plurality of tubes of said third reversal chamber membrane panel connected to and in fluid communication with said second top header pipe and a transverse bottom header pipe, said transverse bottom header pipe connected to and in fluid communication with said first bottom header pipe and said second bottom header pipe, said plurality of tubes adapted to receive said fluid from said transverse bottom header pipe and supply said fluid to said second top header pipe;
wherein said first, second, and third reversal chamber membrane panels form three barriers and a fourth open end of said internal reversal chamber is operatively juxtaposed with one of said first and second operative ends of said furnace chamber such that said internal reversal chamber and said furnace chamber are connected to and in fluid communication with each other.
3. The hybrid boiler system as claimed in claim 1 or claim 2, wherein the length of said plurality of tubes in said internal reversal chamber is greater than the length of said plurality of tubes in said furnace chamber in an operative vertical direction.
4. The hybrid boiler system as claimed in claim 1, wherein said boiler shell and said first and said second top header pipes are in fluid communication with each other via at least one riser conduit.
5. The hybrid boiler system as claimed in claim 1, wherein said boiler shell and said first and said second bottom header pipes are in fluid communication with each other via at least one downcomer conduit.
6. The hybrid boiler system as claimed in claim 1, wherein said hybrid boiler system comprises a plurality of baffles, said plurality of baffles adapted to increase residence time of said flue gas in said furnace chamber.
7. The hybrid boiler system as claimed in claim 1, wherein said hybrid boiler system comprises an air inlet adapted to supply air for combustion of fuel.
8. The hybrid boiler system as claimed in claim 1, wherein said combustor is one of a stationary grate, a bubbling bed, a chain grate, a moving grate, a reciprocating grate, an underfeed stoker, and a fluidized bed.