CN114151791B

CN114151791B - Power generation system and start-stop combustion device thereof

Info

Publication number: CN114151791B
Application number: CN202010934371.2A
Authority: CN
Inventors: 王翰林; 陈姗姗; 薛云鹏; 邱严; 李初福; 王巍; 刘智恩; 郑海波
Original assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy; New Energy Co Ltd of China Energy Investment Corp Ltd
Current assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy; New Energy Co Ltd of China Energy Investment Corp Ltd
Priority date: 2020-09-08
Filing date: 2020-09-08
Publication date: 2023-11-03
Anticipated expiration: 2040-09-08
Also published as: CN114151791A

Abstract

The invention discloses a power generation system and a start-stop combustion device thereof, wherein the start-stop combustion device (100) comprises a rotational flow gas cylinder (1), a plurality of rotational flow gas inlets (101) are formed in the circumferential wall of the cylinder at intervals along the circumferential direction, and the rotational flow gas inlets are arranged in a rotational flow shape which enables the inflow cathode tail gas flow to form a rotational flow shape which is attached to the inner wall surface of the circumferential wall of the cylinder in a rotational flow cylinder cavity (A); and the combustion flue gas outlet (B) of the burner is positioned at the center part of the bottom end of the cyclone cylinder cavity. The power generation system comprises a power generation module (200) and a cathode heat exchanger (300) which are in a pile tower structure and are arranged on the periphery of the start-stop combustion device in a surrounding mode, and a cathode air inlet pipe (201) of the power generation module and mixed flue gas discharged by the start-stop combustion device form heat exchange in the cathode heat exchanger. The invention solves the problems of energy optimal utilization, safety and stability in the process of starting and stopping fuel gas in the synthetic gas power generation system.

Description

Power generation system and start-stop combustion device thereof

Technical Field

The invention belongs to the technical field of gas power generation, and particularly relates to a power generation system and a start-stop burner thereof.

Background

In the existing high-power fuel gas power generation SOFC system, the starting combustion and tail gas treatment functions are generally the same burner device. In the starting process, natural gas enters a combustor, and combustion flue gas is mixed into cathode tail gas flow through a radiator and further exchanges heat with a reformer, a cathode heat exchanger and the like so as to realize full utilization of heat. Specifically, the burner is usually arranged at the bottom of the outer side of the hot box, and adopts synthetic gas as fuel, and the diffusion combustion mode has the advantages of large flue gas flow and high temperature. The flue gas is directly mixed into the cathode tail gas flow and then enters a cathode heat exchanger, and the temperature of the cathode inlet gas flow is heated and raised by the cathode heat exchanger, so that the starting process of the whole system is completed, and the shutdown process follows the reverse process.

For a synthetic gas IGFC system, the start-stop burner needs to use synthetic gas as fuel, the fuel is rich in hydrogen, and compared with natural gas, the flame propagation speed is high, and flashback is easy to form. The heat value of the synthetic gas is low, the flow of the flue gas is large under the same heat load condition, and the flue gas is directly injected into the tail part of the cathode exhaust, so that the back pressure fluctuation of the system is easy to be caused, and the problems that the stack system is overpressurized or the combustion flue gas cannot be normally discharged are possibly caused. Because the gas between the burner flue gas and the heat exchanger in the existing design is not provided with a mixing mechanism, the mixing sufficiency can not be ensured. Under abnormal conditions, such as damage or failure of regulation of the burner, the outlet temperature of the burner is abnormally increased or under overpressure conditions, and emergency cooling and pressure discharging measures are absent.

In addition, compared with the natural gas burner, the natural gas burner can select a plurality of combustion modes such as premixing, non-premixing and the like, and the synthetic gas burner is more suitable for a diffusion combustion mode so as to ensure the safety. Because the synthesis gas system lacks heat absorbing elements such as a reformer and the like, and adopts a diffusion combustion mode, local high-temperature points possibly existing in combustion flame and smoke are formed; if insufficient mixing with stack cathode exhaust is achieved, it may cause excessive local temperatures in the module, resulting in damage or reduced service life.

Disclosure of Invention

Aiming at the defects or shortcomings of the prior art, the invention provides the power generation system and the start-stop combustion device thereof, which can effectively promote the mixing of smoke, have small back pressure fluctuation, smoother combustion and smoke flow, longer service life of components, more compact structure and effectively improve the thermal efficiency of the system.

To achieve the above object, according to one aspect of the present invention, there is provided a start-stop combustion apparatus of a power generation system, the start-stop combustion apparatus comprising:

the cyclone gas collecting cylinder comprises a cylinder circumferential wall and a cyclone cylinder cavity defined by the cylinder circumferential wall in a surrounding mode, wherein a plurality of cyclone gas inlets are formed in the cylinder circumferential wall at intervals along the circumferential direction, and the cyclone gas inlets are arranged to enable the inflow electrode tail gas flow to form a cyclone shape in the cyclone cylinder cavity, wherein the cyclone shape is attached to the inner wall surface of the cylinder circumferential wall; and

and a combustion flue gas outlet of the burner is positioned at the center part of the bottom end of the cyclone cylinder cavity.

In some embodiments, the swirl inlet is formed as an axial groove extending axially through the peripheral wall of the barrel, and the swirl inlet is provided with a swirl inducer.

In some embodiments, the swirl inlet is a stamped port and the swirl inducer is a stamped residual skirt connected to a side wall of the stamped port.

In some embodiments, the start-stop combustion device comprises a mixed flue gas outlet pipe connected to a top central portion of the swirl tube cavity.

In some embodiments, an air conditioning pipe for inputting air or for releasing pressure is connected to the mixed flue gas outlet pipe.

Further, the air conditioning duct may extend through the mixed flue gas outlet duct and downwardly into the cyclone barrel cavity towards the combustion flue gas outlet.

In some embodiments, the burner comprises:

a burner outer housing;

a flame tube which is arranged in the burner outer shell, and the top end opening of the flame tube is formed into the combustion flue gas outlet;

the combustion seat is arranged at the bottom of the cylinder cavity of the flame cylinder; and

and the air inlet pipe assembly is used for introducing combustion gas to the combustion seat.

In some embodiments, an annular cavity-shaped air circulation cavity is defined between the burner outer shell and the flame tube, the bottom wall of the burner outer shell is provided with an air inflow hole serving as an inlet of the air circulation cavity, and the flame tube is provided with an air through hole serving as an outlet of the air circulation cavity;

The burner further comprises a guide cylinder nested between the burner outer shell and the flame cylinder, wherein the bottom end of the guide cylinder is connected with the bottom wall of the burner outer shell, and the top end of the guide cylinder is arranged at intervals with the top wall of the burner outer shell, so that an air baffling flow passage flowing from the air inflow hole to the air through hole is separated in the air circulation cavity.

In some embodiments, an air distribution plate is arranged at the bottom of the flame tube and is used for dividing a tube cavity of the flame tube into an upper flame tube combustion cavity and a lower combustion seat accommodating cavity, and the air through holes comprise first air through holes arranged on the peripheral wall of the combustion seat accommodating cavity and second air through holes arranged on the peripheral wall of the flame tube combustion cavity;

wherein, from the first air through hole flow into the combustion seat holds the air current of chamber a part flow direction in order to form primary air to the combustion seat, another part forms the secondary air through the cloth wind hole on the air cloth gas board, from the second air through hole flow into the air current of flame tube combustion chamber forms tertiary air.

In some embodiments, the air via further comprises a plurality of film cooling holes spaced apart on a peripheral wall of the flame tube.

Further, a plurality of film cooling hole rings which are sequentially arranged at intervals along the axial direction can be arranged on the peripheral wall of the flame tube, and each film cooling hole ring comprises a plurality of annular film cooling holes which are arranged at intervals along the circumferential direction.

Furthermore, shielding guide ring strips corresponding to the air film cooling hole rings can be arranged on the inner peripheral wall of the flame tube, and the shielding guide ring strips are radially inwards spaced apart from the air film cooling holes and form an air film forming ring groove which is open towards the upper side.

In some embodiments, the combustion seat comprises:

a combustion base, in which a gas distribution cavity is arranged;

the inner ring seat is arranged above the combustion base, and a plurality of gas distribution holes which are communicated with the gas distribution cavity and distributed in an annular shape are formed in the top surface of the inner ring seat; and

the outer ring seat is installed above the combustion base in a nested manner with the inner ring seat, the outer ring seat is provided with a plurality of circumferential wall air through holes distributed at intervals along the circumferential direction, and an air circulation annular cavity is formed between the outer ring seat and the inner ring seat.

Further, the combustion seat may include:

the flame stabilizing expander is in an upward flaring cone shape and is arranged above the outer ring seat around the inner ring seat;

The air flow sequentially passing through the peripheral wall air through holes and the air circulation annular cavity and the gas flow passing through the gas distribution holes generate mixed combustion in the flame stabilizing expander.

In some embodiments, the peripheral wall air through holes and the gas distribution holes are swirl holes for forming a same-direction swirl, a horizontal included angle is formed between a hole axis of the swirl holes and a horizontal plane, and the hole axes are inclined towards the same circumferential side.

In some embodiments, the burner comprises:

the air distributor is connected to the bottom end of the burner outer shell and internally provided with an air distribution cavity, and the air distribution cavity is communicated with the air circulation cavity through the air inflow hole penetrating through the top wall.

In some embodiments, the air inlet pipe assembly comprises a nested tubular air interface pipe and a gas interface pipe, the gas interface pipe penetrates through the air distributor to extend into the combustion seat, and the air interface pipe extends out of the bottom wall of the air circulation cavity and is sleeved outside the gas interface pipe.

In some embodiments, the burner outer housing comprises:

the burner upper shell is coaxially arranged with the flame tube and extends into the bottom of the cyclone tube cavity, and the top end of the flame tube is arranged on the top wall of the burner upper shell in a penetrating way; and

The top end of the lower burner shell is respectively connected with the bottom end of the cyclone gas cylinder and the bottom end of the upper burner shell.

According to another aspect of the present invention, there is provided a power generation system including:

according to the start-stop combustion device provided by the invention;

the power generation module is in a pile tower structure and surrounds the circumference of the start-stop combustion device; and

and the cathode heat exchanger is used for forming heat exchange between a cathode air inlet pipe of the power generation module and the mixed flue gas exhausted by the start-stop combustion device.

In some embodiments, the fuel gas of the start-stop combustion device is fuel syngas of hydrogen and carbon monoxide.

In some embodiments, the cathode heat exchanger is a plate heat exchanger.

In the power generation system and the start-stop combustion device thereof, the swirling flow gas cylinder serving as the mixing mechanism is additionally arranged, and the swirling flow gas arrangement mode is adopted, so that the rapid and uniform mixing of cathode tail gas and high-temperature combustion flue gas is ensured, and the damage of a local high-temperature point protection tail heat exchanger by high temperature is eliminated. The flue gas outlet of the burner can be arranged in a low-pressure area, so that the flue gas is discharged conveniently, the flue gas is prevented from flowing backwards, and the back pressure of the module is kept stable. The start-stop combustion device is arranged in the tower stacking center of the power generation module, so that the structural integration level of a system product can be improved, the structure is more compact, heat dissipation is realized in the system, the heat loss is minimum, and the heat utilization rate of the system is improved.

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate the invention and together with the description serve to explain, without limitation, the invention. In the drawings:

FIG. 1 is a schematic diagram of the operation of a start-stop combustion device of a power generation system according to an embodiment of the present invention;

FIG. 2 is a perspective view of a start-stop combustion device of a power generation system in accordance with an embodiment of the present invention;

FIG. 3 is a cross-sectional view of the power generation system of FIG. 2, the cross-sectional view being an axial section through the central axis of the swirl gas cartridge;

FIG. 4 is an enlarged view of a portion of the encircled portion of FIG. 3 showing in particular the internal structure of the burner portion;

FIG. 5 is an exploded view of an assembly of a swirl cylinder and a burner in the power generation system shown in FIG. 2;

FIG. 6 is a cross-sectional view of the portion of the swirl gas cartridge of FIG. 5 showing the swirl flow guide therein;

FIG. 7 is an assembled exploded view of the burner section of FIG. 5;

FIG. 8 is a perspective view of the cartridge of FIG. 7;

FIG. 9 is a cross-sectional view of the burner portion of FIG. 5, clearly showing the internal structure of the burner and the air flow direction, with arrows representing the air deflection flow paths;

FIGS. 10a to 10c are schematic structural views of the burner block of FIG. 7, showing a perspective assembled exploded view, a plan sectional exploded view and an assembled sectional view of the burner block, respectively;

FIG. 11 is a perspective view of a power generation system according to an embodiment of the present invention;

FIG. 12a is a graph of the temperature profile (K) of the burner split at the lower operating temperature limit;

FIG. 12b is a graph of the OH free radical concentration profile of the faceted intermediate product of the combustor at the lower heat load operating condition;

FIG. 12c is a graph (K) of the wall temperature of the flame tube under the lower limit working condition of the heat load;

FIG. 12d is a plot of the burner split temperature profile (K) under the upper heat load operating condition;

FIG. 12e is a graph showing OH free radical concentration profile of a faceted intermediate product in a combustor during an upper heat load condition; and

FIG. 12f is a graph (K) showing the temperature distribution of the wall surface of the flame tube under the upper limit working condition of the heat load.

Reference numerals illustrate:

100 start-stop combustion device 200 power generation module

300 cathode heat exchanger

1 rotational flow gas cylinder 2 mixed smoke outlet pipe

3 air conditioning pipe 4 burner upper shell

5 combustor lower shell 6 air distributor

7 draft tube 8 flame tube

9 air distribution plate 10 flame stabilizing expander

11 inner ring seat 12 outer ring seat

13 combustion base 14 air interface tube

15 gas interface tube 16 igniter

61 air inflow hole 62 sealing installation ring groove

81 first air via 82 second air via

83 air film cooling hole 84 shielding guide ring strip

85 air film forming ring groove

101 rotational flow air inlet 102 rotational flow guide piece

111 gas distribution hole 121 circumference wall air through hole

122 air circulation ring cavity 131 gas distribution cavity

201 cathode air inlet pipe 202 cathode tail gas pipe

203 combustor outlet thermocouple measurement point

204 heat exchanger high temperature inlet temperature measuring point

205 heat exchanger high temperature outlet temperature measuring point

A swirl tube cavity B combustion flue gas outlet

C air circulation cavity D flame tube combustion cavity

E combustion seat accommodation cavity F air distribution cavity

Detailed Description

The following describes specific embodiments of the present invention in detail with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

It should be noted that, without conflict, the embodiments of the present invention and features of the embodiments may be combined with each other.

In the present invention, unless otherwise indicated, terms of orientation such as "upper, lower, top, bottom" are used generally with respect to the orientation shown in the drawings or with respect to the positional relationship of the various components with respect to one another in the vertical, vertical or gravitational directions.

The invention will be described in detail below with reference to the drawings in connection with embodiments.

The invention firstly discloses a start-stop combustion device of a power generation system. In the specific embodiments with reference to the drawings, a 20 kw-level IGFC syngas power generation system arranged in a ring shape is taken as an example, and a start-stop combustion device and other functional parts thereof are described in detail.

The start-stop combustion device also adopts the synthetic gas as the fuel, is the same as the power generation system, ensures the fuel input consistency of the module, namely, different from the prior start-stop combustion device which adopts methane as the fuel gas, the synthetic gas of hydrogen and carbon monoxide can be adopted as the fuel gas, but the invention is not limited to the fuel gas. As shown in fig. 1, the operating principle of the start-stop combustion device is as follows: after the synthesis gas and the air are combusted in the flame tube 8, the combustion flue gas enters the cyclone gas cylinder 1 and is fully mixed with cathode tail gas, the formed high-temperature mixed gas enters the cathode heat exchanger 300 to preheat the air entering the electric pile, the preheated air enters the electric pile as cathode air inlet, and the low-temperature mixed gas formed after heat exchange is discharged outwards.

The invention aims to solve the problems of energy optimal utilization, safety and stability in the process of starting and stopping fuel gas in a synthetic gas power generation system. Under the premise of ensuring safety, the temperature rise and fall speed of the system is quickened, and the energy utilization efficiency is improved. Therefore, based on the working principle, the invention provides a start-stop combustion device of a power generation system. As shown in fig. 2 to 10c, the start-stop combustion apparatus 100 includes:

The swirl gas cartridge 1 comprises a cartridge peripheral wall and a swirl cartridge chamber a defined around the cartridge peripheral wall as shown in fig. 5, 7. Wherein, a plurality of rotational flow air inlets 101 are arranged on the circumferential wall of the cylinder at intervals along the circumferential direction, the swirl inlet 101 is provided so that the electrode off-gas flow flowing in can form a swirl shape in the swirl cylinder chamber a against the inner wall surface of the cylinder peripheral wall; and

the combustion flue gas outlet B of the burner is positioned at the center part of the bottom end of the cyclone cylinder cavity A.

The invention additionally provides a cyclone gas cylinder 1 serving as a mixing mechanism, and adopts a cyclone gas arrangement mode to ensure that cathode tail gas and high-temperature combustion flue gas are quickly and uniformly mixed, ensure the surface temperature of a gas mixing structure and protect the use safety of high-temperature elements and heat exchangers, aiming at the defect that the mixing sufficiency cannot be ensured because the mixing mechanism is not arranged on the gas between the combustion flue gas and the cathode heat exchanger 300 in the existing design. The cyclone cylinder cavity A with larger volume forms a buffer effect, reduces the back pressure of a galvanic pile, and can simultaneously place the outlet of the burner in a low-pressure area to prevent the flue gas from flowing backwards.

Referring to fig. 4 and 5, a large-cavity swirl gas cylinder 1 is disposed at the cathode exhaust gas outlet, and air swirl can be formed in the swirl cylinder cavity a in the same direction as the swirl direction of combustion flue gas discharged from a burner as will be described in detail below. Thus, the cathode tail gas enters the cyclone cylinder cavity A through the cyclone air inlet 101 at the periphery, the combustion flue gas enters the cyclone cylinder cavity A from the bottom center, and the cyclone cylinder cavity A has a large volume and can play a role in gas buffering. The two inner and outer rotational flows can be fully mixed, the inner rotational flow is high-temperature combustion flue gas, the outer rotational flow is cathode tail gas with relatively low temperature, so that the two rotational flows can be fully mixed in the rotational flow process, local high-temperature points can be eliminated in the uniform mixing process, and the outer rotational flow can protect the cylinder wall surface of the rotational flow gas cylinder 1, the cathode heat exchanger 300 and the like. The combustion flue gas rises and mixes in the whirl section of thick bamboo chamber A of whirl, can form the low pressure district in section of thick bamboo central part, brings the negative pressure effect, and the flue gas of the combustion flue gas export B of the combustor of being convenient for discharges and reduces the combustor air inlet pressure, is favorable to keeping the module backpressure stable.

The flow of the cathode tail gas can be kept unchanged in the start-stop process, and the temperature of the combustion flue gas can be further controlled on the basis, so that the temperature of the high-temperature mixed gas after the combustion flue gas and the cathode tail gas are mixed can be controlled, and the damage to heat-preservation components and the reduction of the service life caused by local overtemperature in the module can be avoided. The cathode exhaust flow can be kept unchanged, the variation of the synthesis gas is extremely small when the temperature of the combustion flue gas is regulated, the influence on the flow of the combustion flue gas is small, and the stability of the flow of the combustion flue gas under different regulating working conditions can be ensured.

In order to form a swirl shape of the electrode exhaust gas flow in the swirl cylinder chamber a, which is bonded to the inner wall surface of the cylinder peripheral wall, as shown in fig. 4, 5 and 7, in the present embodiment, the swirl inlet 101 on the cylinder peripheral wall of the swirl cylinder 1 is designed as an axial groove shape penetrating the cylinder peripheral wall and extending in the axial direction, and a swirl guide 102 is provided at the swirl inlet 101. Wherein, a plurality of axial grooves which are arranged at intervals on the periphery and extend to the end part as far as possible along the axial direction can ensure that the cathode tail gas with large flow enters the cyclone cylinder cavity A, and when the cathode tail gas passes through the cyclone air inlet 101, the cyclone flow entering the cyclone cylinder cavity A along the tangential direction of the cylinder peripheral wall can be formed by the tangential flow guiding function of the cyclone flow guiding piece 102.

Alternatively, the swirl flow guide 102 may be a circumferential side wall of the swirl air inlet 11, that is, the circumferential side wall is formed as a tangential inclined wall, and the cathode exhaust passing through the swirl air inlet 11 flows down the tangential inclined wall to form a fluid in a tangential direction, thereby forming a swirl on the inner wall of the circumference of the swirl gas cylinder 1, and the low-temperature swirl may protect the wall of the swirl gas cylinder 1. In this embodiment, referring to fig. 5 and 7, the swirl inlet 101 is a stamped port, and the swirl inducer 102 is a stamped residual skirt connected to the side wall of the stamped port. The stamping residual skirt is positioned in the cyclone cylinder cavity A, and the diversion surface extends along the tangential direction.

As shown in fig. 1, the combustion flue gas and the cathode exhaust gas are mixed in the same direction rotational flow in a rotational flow gas cylinder 1 to form high-temperature mixed gas. Referring to fig. 2, the start-stop combustion apparatus 100 includes a mixed gas outlet pipe 2, the mixed gas outlet pipe 2 being connected to a top center portion of the cyclone cylinder chamber a to introduce high-temperature mixed gas into the cathode heat exchanger 300 for preheating air entering through a cathode inlet pipe 201 on one side by heat exchange, and the preheated air further entering into the electric pile through the cathode inlet pipe 201 on the other side. The high-temperature mixed gas after heat exchange becomes low-temperature mixed gas and can be discharged through the cathode tail gas pipe 202.

In particular, in the present embodiment, an air conditioning duct 3 for inputting air or for releasing pressure is also connected to the mixed flue gas outlet duct 2, as shown in fig. 2 to 4. An air conditioning pipe 3 is arranged in front of the cathode heat exchanger 300 as an air conditioning port and an air vent, so that protective intervention can be conveniently implemented under the condition of overtemperature and overpressure or emergency conditions, and overtemperature and overpressure protection of a high-temperature element is provided. Namely, if necessary, the air is exhausted outwards through the air adjusting pipe 3 to release pressure, so that the back pressure stability and the module safety are ensured, or extra air can be introduced into the cyclone cylinder cavity A through the air adjusting pipe 3 under the condition that the cathode heat exchanger 300 is over-temperature or the like, so that the temperature of high-temperature mixed gas is reduced, and the cathode heat exchanger 300 is protected.

Referring to fig. 3, the air conditioning duct 3 may directly pass through the mixed flue gas outlet duct 2 and extend vertically downward into the cyclone tube cavity a to be close to the combustion flue gas outlet B, so that the evacuation and pressure relief effects are better, or the supplemented air may participate in the cyclone mixing earlier to reduce the high temperature mixture temperature more effectively.

Fig. 5 and 6 illustrate an assembly view and an exploded view of the burner in the present embodiment, respectively. Specifically, the burner includes:

a burner outer housing;

a flame tube 8 which is arranged in the outer shell of the burner, and the top opening of the flame tube 8 is formed into a combustion flue gas outlet B;

The combustion seat is arranged at the bottom of the cylinder cavity of the flame cylinder 8; and

and the air inlet pipe assembly is used for introducing combustion gas towards the combustion seat.

In the burner of the present invention, since the amount of the air intake is large and the synthetic gas ratio is small, the temperature adjustment range is wide, and thus the stability of the small gas ratio is problematic. Therefore, the design of the burner aims at realizing swirl combustion, ensuring that the temperature adjustable range is large under different heat load requirements, and simultaneously keeping the flow change of combustion flue gas small, namely keeping the flue gas flow stable, so that the back pressure fluctuation is small.

For large flows of air, to achieve stable and continuous combustion, it should be ensured that the air is supplied sufficiently stably, and that the air flow rate, distribution, etc. should be balanced. Accordingly, as shown in fig. 9, an annular air flow chamber C is defined between the burner housing and the flame tube 8, the bottom wall of the burner housing is provided with an air inflow hole 61 as an inlet of the air flow chamber C, and the flame tube 8 is provided with an air passage hole as an outlet of the air flow chamber C; wherein in particular the burner further comprises a guide shell 7 nested between the burner outer housing and the flame tube 8, the bottom end of the guide shell 7 being connected to the bottom wall of the burner outer housing and the top end being spaced from the top wall of the burner outer housing such that in the air flow chamber C an air deflection flow path is separated from the air inflow hole 61 to the air passage hole, as indicated by the arrow in fig. 9.

Therefore, by additionally arranging the guide cylinder 7 to form air deflection, the air flow pressure in the combustor can be stabilized, the air in the space can be uniformly distributed, the multistage combustion can be conveniently formed, the combustion of the synthetic gas is more sufficient, and the thermal efficiency is improved. In addition, in order to seal the space in the air circulation chamber C to form the air baffling flow passage, the bottom end of the guide cylinder 7 should be sealingly mounted on the bottom wall of the burner (i.e., the top wall of the air distributor 6). Specifically, as shown in fig. 9, a seal installation ring groove 62 may be provided on the bottom wall of the burner, a seal rubber strip or the like is embedded, and then the bottom end of the guide cylinder 7 is press-fitted on the seal rubber strip.

As shown in fig. 4 and 9, an air distribution plate 9 is arranged at the bottom of the flame tube 8, air distribution holes (not shown in the drawings) are densely distributed on the air distribution plate 9, the air distribution plate 9 divides the tube cavity of the flame tube 8 into an upper flame tube combustion cavity D and a lower combustion seat accommodating cavity E, and the burner is arranged in the combustion seat accommodating cavity E.

Referring to fig. 8, the air through holes provided on the flame tube 8 may include a first air through hole 81 provided on the peripheral wall of the burner block receiving chamber E and a second air through hole 82 provided on the peripheral wall of the flame tube combustion chamber D; as shown in fig. 9, a part of the air flow flowing into the combustion seat accommodating chamber E from the first air through holes 81 can flow to the central combustion seat in the radial direction to form primary air, primary combustion is formed on the burner with the synthetic gas, the other part can enter the flame tube combustion chamber D upwards through the air distribution holes on the air distribution plate 9 to form secondary air to participate in secondary combustion, and the air flow flowing into the flame tube combustion chamber D from the second air through holes 82 close to the air distribution plate 9 above can form tertiary air to participate in tertiary combustion to realize complete combustion of the synthetic gas and ensure the uniformity of the temperature of the flue gas outlet. Therefore, in the embodiment, the three-time combustion of the synthesis gas is realized, the gas is fully utilized, and the gas utilization rate is high. Of course, the present invention is not limited to three combustions, but may be two combustions or more.

When the synthetic gas and the air are combusted for many times in the flame tube 8, the generated high temperature causes continuous high temperature damage to the wall of the flame tube 8. For this reason, in the present embodiment, the air via hole may further include a plurality of film cooling holes 83 spaced apart from each other on the circumferential wall of the flame tube 8 to protect the flame tube 8. As shown in fig. 8, in the present embodiment, the sizes of the first air via hole 81, the second air via hole 82, and the air film cooling hole 83 are sequentially decreased to achieve reasonable distribution of air, but the present invention is not limited to the sizes of the air via holes, and can be adjusted and set according to functional requirements.

Further, to completely protect the inner wall of the flame tube, a film ring may be formed through the film cooling holes 83. Specifically, referring to fig. 8 and 9, a plurality of film cooling hole rings are provided on the circumferential wall of the flame tube 8 at intervals in the axial direction, and each film cooling hole ring includes a plurality of film cooling holes 83 arranged at intervals in the circumferential direction in a ring shape. In this way, when the air flow in the air circulation cavity C flows along the air baffling flow channel indicated by the arrow in fig. 9, each air via hole on the outer wall surface of the flame tube 8 enters the inner cavity of the flame tube, and the air flow entering through the air film cooling hole ring can be attached to the inner cylinder wall surface to form an annular air film, so as to completely protect the inner wall in the circumferential direction.

In order to facilitate the formation of the film ring and to make the film ring more closely contact with the inner wall, the inner peripheral wall of the flame tube 8 is provided with a shielding guide ring strip 84 corresponding to the film cooling hole 83 ring, and the shielding guide ring strip 84 radially inwardly spaces the film cooling hole 83 and forms a film forming ring groove 85 opening upward. Specifically, the shielding guide ring strips 84 are spaced apart from the inner wall surface provided with the film cooling holes 83 in the radial direction, and the formed annular spacing grooves are the film forming annular grooves 85 with openings at the upper part, the shielding guide ring strips 84 are used for blocking the air flow passing through the film cooling holes 83 from flowing inwards in the radial direction, guiding the air flow to the attached inner wall to flow upwards, and flowing out of the film forming annular grooves 85 upwards to form the air film ring. In fig. 9, the axial distance between adjacent shielding guide ring strips 84 is small, and the gas film ring flowing upwards from the gas film forming ring groove 85 of the shielding guide ring strip 84 positioned below can completely cover the inner wall surface of the flame tube between the adjacent shielding guide ring strips 84. Thus, the inner peripheral wall of the flame tube 8 can be completely covered by a plurality of air film rings in an axial segmented mode, so that the complete low-temperature protection is formed, and the service life of the flame tube is prolonged.

To achieve swirl combustion, see fig. 10 a-10 c, in one embodiment, the combustion seat comprises:

A combustion base 13, in which a gas distribution chamber 131 is provided;

the inner ring seat 11 is arranged above the combustion base 13, and a plurality of gas distribution holes 111 which are communicated with the gas distribution cavity 131 and distributed in an annular shape are formed in the top surface of the inner ring seat 11; and

the outer ring seat 12 is installed above the combustion base 13 in a nested manner with the inner ring seat 11, the outer ring seat 12 is provided with a plurality of circumferential wall air through holes 121 distributed at intervals along the circumferential direction, and an air circulation annular cavity 122 is formed between the outer ring seat 12 and the inner ring seat 11.

Further, the combustion seat can also comprise a flame stabilizing expander 10 which is in a cone shape flaring upwards and is arranged above the outer ring seat 12 in a surrounding manner of the inner ring seat 11; wherein the air flow sequentially passing through the circumferential wall air through holes 121 and the air circulation annular chamber 122 and the gas flow passing through the gas distribution holes 111 produce mixed combustion in the flame stabilizing expander 10.

It can be seen that the combustion seat of this embodiment adopts a non-integral structure, and includes a plurality of constituent components. Aiming at the characteristics of low calorific value, rich hydrogen and the like of the synthesis gas, the single-nozzle double-cyclone diffusion burner is adopted, and is suitable for large-range load transformation to adapt to start-stop process adjustment. The adoption of the synthetic gas cyclone diffusion single-nozzle burner can ensure the combustion safety of the synthetic gas, prevent backfire and remove local high-temperature points of combustion flue gas. The flue gas flow is stable under different working conditions, the thermal load adjusting range is large, and the control module is beneficial to stack backpressure control in the start-stop process.

Specifically, the peripheral wall air through holes 121 and the gas distribution holes 111 are swirl holes for forming a co-directional swirl, that is, the hole axes of the swirl holes have a horizontal angle with the horizontal plane and the hole axes are inclined toward the same circumferential side. Thus, as previously described, a substantial portion of the air flow flowing from the air circulation chamber C through the first air passage holes 81 into the combustion seat accommodating chamber E flows generally radially inwardly toward the combustion seat, creating an air swirl flow through the peripheral wall air passage holes 121 in the outer annular seat 12 into the air circulation annular chamber 122 shown in fig. 10C. Then, the air swirling flow is mixed with the gas swirling flow flowing out through the gas distribution chamber 131 and the gas distribution holes 111, and under the point activation of the igniter 16, primary combustion is generated in the flame stabilizing expander 10, and simultaneously upward swirling flow smoke is generated.

Referring to fig. 4 and 9, the burner further includes an air distributor 6, which is connected to the bottom end of the burner housing and has an air distribution chamber F therein, the air distribution chamber F being in communication with the air circulation chamber C through an air inflow hole 61 penetrating the top wall. Therefore, the air distribution cavity F can play a role in buffering and reducing pressure of high-flow air, and can further perform air cooling and heat dissipation on the bottom wall of the combustor, on one hand, the cooling wall surface is protected, and on the other hand, the combustion air is preheated.

Referring to fig. 2-4, the air inlet tube assembly may include a nested tubular air interface tube 14 and a gas interface tube 15, the gas interface tube 15 extending through the air distributor 6 into the combustion seat, the air interface tube 14 extending from the bottom wall of the air flow chamber C and being sleeved outside the gas interface tube 15. In the air-fuel double swirl diffusion combustion burner adopted in the present embodiment, the required air flow is far greater than the synthetic gas flow, so the illustrated air interface tube 14 is wrapped around the gas interface tube 15 in a nested manner, and the pipe diameter ratio of the two is approximately adapted to the flow ratio of the conveyed air flow.

As mentioned above, the burner of the present invention should ensure that the flow of flue gas is kept stable under different heat load requirements with small back pressure fluctuations. Therefore, a fixed air flow rate adjusting mode can be adopted to keep the flue gas flow rate stable. Therefore, the high-temperature mixed gas generated after the combustion flue gas and the cathode tail gas are mixed can be kept unchanged under different working conditions in the start-stop process, and the back pressure stability or the back pressure fluctuation is ensured to be smaller after the tail part of the fuel cell is input into the module.

Specifically, the air flow is maintained constant during operation, i.e., the air flow to the burner via the air interface tube 14 is maintained constant, and the temperature of the exiting combustion flue gas is adjusted by adjusting the fuel flow (i.e., changing the amount of syngas flow in the gas interface tube 15). Since the fuel flow is much smaller than the air flow, the flow of combustion fumes can remain substantially stable under different loads.

Further, as shown in fig. 5 and 6, the burner housing may include:

the upper shell 4 of the burner is coaxially arranged with the flame tube 8 and extends into the bottom of the cyclone tube cavity A, and the top end of the flame tube 8 is arranged on the top wall of the upper shell 4 of the burner in a penetrating way; and

the top end of the burner lower shell 5 is respectively connected with the bottom end of the cyclone gas cylinder 1 and the bottom end of the burner upper shell 4.

The burner shell has the advantages that the burner upper shell 4 and the flame tube 8 can be arranged coaxially and extend into the bottom of the cyclone tube cavity A conveniently, the burner upper shell 4, the cyclone gas cylinder 1 and the burner lower shell 5 can be positioned coaxially more conveniently, and the burner upper shell, the cyclone gas cylinder 1 and the burner lower shell are fixedly connected to a mounting substrate (not shown) together through a flange mode.

On the basis of the start-stop combustion device 100, the invention also discloses a power generation system, and in the embodiment shown in fig. 11, the power generation system comprises:

the above-described start-stop combustion apparatus 100;

the power generation module 200 is in a pile tower structure and is arranged around the circumference side of the start-stop combustion device 100; and

the cathode heat exchanger 300, the cathode air inlet pipe 201 of the power generation module 200 and the mixed flue gas discharged from the start-stop combustion device 100 form heat exchange in the cathode heat exchanger 300.

In the power generation system, the start-stop combustion device 100 is arranged in the center of the module, namely the center position of the tower stack of the power generation module 200, so that the concentricity is ensured, the structural integration level of a system product is improved, the structure is more compact, heat is dissipated in the system, the heat loss is minimum, and the heat utilization rate of the system is improved.

During the start-up and shutdown of the power generation system, the stack air intake of the power generation module 200 is kept unchanged, the burner is started, the air intake of the burner is kept basically unchanged after ignition, and the outlet temperature of the combustion flue gas is adjusted by adjusting the fuel amount of the synthesis gas. In the cyclone gas cylinder 1, cathode tail gas and combustion flue gas form internal and external layered homodromous cyclone mixing, and high-temperature mixed gas is formed after the mixture is fully mixed and flows into the cathode heat exchanger 300 through the mixed flue gas outlet pipe 2. Wherein, the preheating temperature of the cathode inlet air flow can be adjusted by adjusting the outlet temperature of the combustion flue gas. Since the air flow required by the burner is much higher than the gas amount of the synthetic gas, the flow and the quality of the combustion flue gas can be considered to be stable under different working conditions. In an abnormal situation, the air conditioning pipe 3 may be opened to condition air, thereby controlling the intake air temperature of the high-temperature mixture flowing into the cathode heat exchanger 300. After the high-temperature mixed gas enters the cathode heat exchanger 300, the air is heated by the cathode heat exchanger 300 to form cathode air inlet of the electric pile, so that the module heating and program cooling processes are realized.

As shown in fig. 2, a plurality of parameter monitoring points such as a combustor outlet thermocouple measuring point 203, a heat exchanger high temperature inlet temperature measuring point 204, a heat exchanger high temperature outlet temperature measuring point 205 and the like can be set so as to monitor and judge whether temperature and pressure abnormality exists or not, and whether to start the timely air conditioning tube 3 or not.

It should be noted that the cathode heat exchanger of the existing system is an outer cylindrical plate heat exchanger or an outer edge integrated annular plate heat exchanger, and has relatively large volume, large heat dissipation and large thermal inertia in the dynamic process. For a synthesis gas IGFC system, the synthesis gas heating value is lower and the anode flow is larger. In addition, due to the lack of a reforming process, the cathode flow needs to be relatively larger to complete the thermal balance of the system. The cathode flow rate may be 10-15 times of the anode under the design condition, so that cathode temperature and heat management are important for module heat balance. For the synthetic gas fuel, the heat exchange area of the outside cathode heat exchanger is larger, and the flow area is relatively smaller; in addition, for larger flows of air flow, an increase in back pressure may result. Therefore, the synthesis gas system is more suitable for adopting the plate-fin heat exchanger with higher heat exchange intensity and compact structure. The cathode heat exchanger 300 is a plate heat exchanger. The heat exchanger adopts a plate-fin heat exchanger with compact structure and high heat exchange strength, and the heat exchanger has smaller volume and mass and can reduce the thermal inertia of the module.

In the power generation system adopting the synthetic gas, detection tests are carried out under different heat load working conditions, and the following results are obtained:

wherein, the calculated cloud image of OH free radical, temperature and wall temperature of burner flame tube 8 with representative burner middle facets is selected as reference data, and CFD calculation results are shown in fig. 12 a-12 f.

The results show that the flame is normal in shape, has no blow out, no obvious flame lifting or tempering condition, and the combustion reaction zone is coherent and has no obvious fracture. The highest temperature of the wall surface of the burner is about 850 ℃ under the upper limit working condition, and the existing burner structural design can normally and stably burn and operate under the design working condition. The temperature of the outlet flue gas under the upper and lower limit conditions is about 1277 ℃ and 690 ℃.

In summary, the synthetic gas burner of the invention adopts a double-swirl structure of air and fuel, and the head of the burner is provided with an air distribution plate. The fuel gas and the air swirl flow are fully contacted and reacted, primary mixing is formed at the air distribution plate, and the wall surface of the burner is provided with mixing holes for supplementing secondary air and the like, so that the uniformity of the outlet temperature of the combustion flue gas can be ensured. Cool air enters the flame tube through the cooling holes, and a cooling air film is formed near the surface of the flame tube through the diversion effect of the air film ring, so that the safety of the burner under the long-period running condition is protected. The combustion flue gas enters the cyclone gas cylinder 1 from the bottom, the cathode tail gas enters the cyclone gas cylinder 1 from the cyclone gas inlet 101 at the periphery, the gas cylinder has larger volume to form a gas buffering effect, and the back pressure is kept stable. The swirl flow guide member 102 is used for guiding the gas flow direction to swirl in the same direction as the combustion flue gas, the combustion flue gas and the cathode tail gas are uniformly mixed in the swirling process, and the low-temperature gas is close to the inner wall surface of the gas cylinder under the action of swirling centrifugal force, so that the gas cylinder is protected. The combustion flue gas and the cathode tail gas are fully mixed through the rotational flow, so that the damage of the tail heat exchanger caused by high temperature at a local high temperature point is eliminated. The center of the gas cylinder forms a low-pressure area due to the swirling flow of the flue gas, the outlet of the burner is arranged in the low-pressure area to form negative pressure, so that the flue gas is convenient to discharge and fully mix, the inlet pressure of the burner can be reduced, and the back pressure fluctuation risk of the module is reduced.

An air conditioning tube 3 is arranged in front of the cathode heat exchanger 300 as a conditioning air port and a back pressure drain port, which can be used for intervention in emergency situations to protect the heat exchanger and the module stack. Under abnormal conditions, when the temperature of the inlet air of the heat exchanger exceeds the temperature, the air is input to be regulated, the temperature of the air is rapidly reduced, and the heat exchanger is protected from being damaged. Under the abnormal condition of the back pressure of the module, the exhaust can be opened to be discharged, and the back pressure is ensured to be stable.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the specific details of the above embodiments, and within the scope of the technical concept of the present invention, various simple modifications may be made to the technical solution of the present invention, for example, the number, the aperture, and the hole shape of each air via during multi-stage combustion are simply changed, and all the simple modifications belong to the protection scope of the present invention.

In addition, the specific features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described further.

Moreover, any combination of the various embodiments of the invention can be made without departing from the spirit of the invention, which should also be considered as disclosed herein.

Claims

1. A start-stop combustion device for an IGFC synthesis gas power generation system, characterized in that the start-stop combustion device (100) comprises:

the cyclone gas collecting cylinder (1) comprises a cylinder circumferential wall and a cyclone cylinder cavity (A) defined by the cylinder circumferential wall in a surrounding mode, wherein a plurality of cyclone gas inlets (101) are formed in the cylinder circumferential wall at intervals along the circumferential direction, and the cyclone gas inlets (101) are arranged so that the cathode tail gas flow flowing in can form a cyclone shape which is attached to the inner wall surface of the cylinder circumferential wall in the cyclone cylinder cavity (A); and

the combustion flue gas outlet (B) of the burner is positioned at the center part of the bottom end of the cyclone cylinder cavity (A); the burner includes:

a burner outer housing;

a flame tube (8) which is arranged in the burner outer shell, wherein the top end opening of the flame tube (8) is formed into the combustion flue gas outlet (B);

the combustion seat is arranged at the bottom of the cylinder cavity of the flame cylinder (8); and

the air inlet pipe assembly is used for introducing combustion gas comprising air and fuel gas towards the combustion seat, wherein the fuel gas is fuel synthesis gas of hydrogen and carbon monoxide;

the swirl air inlet (101) is formed into an axial groove penetrating through the circumferential wall of the cylinder and extending along the axial direction, and a swirl guide piece (102) is arranged at the swirl air inlet (101); the cyclone air inlet (101) is a stamping forming opening, and the cyclone flow guide piece (102) is a stamping residual skirt connected with the side wall of the stamping forming opening.

2. The start-stop combustion device of a power generation system according to claim 1, characterized in that the start-stop combustion device (100) comprises a mixed flue gas outlet pipe (2), the mixed flue gas outlet pipe (2) being connected to a top central part of the swirl cylinder chamber (a).

3. The start-stop combustion device of the power generation system according to claim 2, characterized in that an air conditioning pipe (3) for inputting air or for releasing pressure is connected to the mixed flue gas outlet pipe (2).

4. A start-stop combustion device of a power generation system according to claim 3, characterized in that the air conditioning duct (3) passes through the mixed flue gas outlet duct (2) and protrudes downwards into the swirl pot chamber (a) towards the combustion flue gas outlet (B).

5. The start-stop combustion device of a power generation system according to claim 1, characterized in that an annular cavity-like air circulation cavity (C) is defined between the burner housing and the flame tube (8), the bottom wall of the burner housing being provided with an air inflow hole (61) as an inlet of the air circulation cavity (C), the flame tube (8) being provided with an air through hole as an outlet of the air circulation cavity (C);

The burner further comprises a guide cylinder (7) which is nested between the burner outer shell and the flame cylinder (8), wherein the bottom end of the guide cylinder (7) is connected with the bottom wall of the burner outer shell, and the top end of the guide cylinder is arranged at intervals with the top wall of the burner outer shell, so that an air baffling flow passage which flows from the air inflow hole (61) to the air through hole is separated in the air circulation cavity (C).

6. The start-stop combustion device of a power generation system according to claim 5, characterized in that the bottom of the flame tube (8) is provided with an air distribution plate (9), the air distribution plate (9) is used for dividing a tube cavity of the flame tube (8) into an upper flame tube combustion cavity (D) and a lower combustion seat accommodation cavity (E), and the air through holes comprise a first air through hole (81) arranged on the peripheral wall of the combustion seat accommodation cavity (E) and a second air through hole (82) arranged on the peripheral wall of the flame tube combustion cavity (D);

wherein a part of the air flow flowing into the combustion seat accommodating cavity (E) from the first air through holes (81) flows to the combustion seat to form primary air, the other part of the air flow forms secondary air through air distribution holes on the air distribution plate (9), and the air flow flowing into the flame tube combustion cavity (D) from the second air through holes (82) forms tertiary air.

7. The start-stop combustion device of a power generation system according to claim 5, characterized in that the air passage holes further comprise a plurality of film cooling holes (83) distributed at intervals on the peripheral wall of the flame tube (8).

8. The start-stop combustion device of a power generation system according to claim 7, wherein a plurality of film cooling hole rings are provided on the peripheral wall of the flame tube (8) at intervals in the axial direction in order, each of the film cooling hole rings including a plurality of the film cooling holes (83) arranged at intervals in the circumferential direction in a ring shape.

9. The start-stop combustion device of a power generation system according to claim 8, characterized in that a shielding guide ring strip (84) corresponding to the film cooling hole (83) ring is provided on the inner peripheral wall of the flame tube (8), and the shielding guide ring strip (84) is radially inwardly spaced from the film cooling hole (83) and forms a film forming ring groove (85) opening upward.

10. The start-stop combustion device of a power generation system of claim 5, wherein the combustion seat comprises:

a combustion base (13) is internally provided with a fuel gas distribution cavity (131);

the inner ring seat (11) is arranged above the combustion base (13), and a plurality of gas distribution holes (111) which are communicated with the gas distribution cavity (131) and distributed in an annular shape are formed in the top surface of the inner ring seat (11); and

The outer ring seat (12) and the inner ring seat (11) are installed above the combustion base (13) in a nested mode, the outer ring seat (12) is provided with a plurality of circumferential wall air through holes (121) distributed at intervals along the circumferential direction, and an air circulation annular cavity (122) is formed between the outer ring seat (12) and the inner ring seat (11).

11. The start-stop combustion device of a power generation system of claim 10, wherein the combustion seat comprises:

the flame stabilizing expander (10) is in an upward flaring cone shape and is arranged above the outer ring seat (12) in a surrounding manner of the inner ring seat (11);

wherein, the air flow passing through the peripheral wall air through hole (121) and the air circulation annular cavity (122) and the gas flow passing through the gas distribution holes (111) generate mixed combustion in the flame stabilizing expander (10).

12. The start-stop combustion device of a power generation system according to claim 10, wherein the peripheral wall air through holes (121) and the gas distribution holes (111) are swirl holes for forming a co-rotating swirl, a horizontal included angle is formed between a hole axis of the swirl holes and a horizontal plane, and the hole axis is inclined towards the same circumferential side.

13. The start-stop combustion apparatus of a power generation system of claim 5, wherein the burner comprises:

and the air distributor (6) is connected to the bottom end of the burner outer shell and internally provided with an air distribution cavity (F), and the air distribution cavity (F) is communicated with the air circulation cavity (C) through the air inflow hole (61) penetrating through the top wall.

14. The start-stop combustion device of a power generation system according to claim 13, characterized in that the air inlet pipe assembly comprises a nested tubular air interface pipe (14) and a gas interface pipe (15), the gas interface pipe (15) extends into the combustion seat through the air distributor (6), and the air interface pipe (14) extends from the bottom wall of the air circulation cavity (C) and is sleeved outside the gas interface pipe (15).

15. The start-stop combustion apparatus of a power generation system of claim 1, wherein the burner outer housing comprises:

the burner upper shell (4) is coaxially arranged with the flame tube (8) and extends into the bottom of the cyclone tube cavity (A), and the top end of the flame tube (8) is arranged on the top wall of the burner upper shell (4) in a penetrating way; and

The burner comprises a burner lower shell (5), wherein the top end of the burner lower shell (5) is respectively connected with the bottom end of the cyclone gas cylinder (1) and the bottom end of the burner upper shell (4).

16. A power generation system, the power generation system comprising:

the start-stop combustion device (100) of a power generation system according to any one of claims 1 to 15;

the power generation module (200) is in a pile tower structure and surrounds the circumference of the start-stop combustion device (100); and

and a cathode heat exchanger (300), wherein a cathode air inlet pipe (201) of the power generation module (200) and mixed flue gas exhausted by the start-stop combustion device (100) form heat exchange in the cathode heat exchanger (300).

17. The power generation system of claim 16, wherein the cathode heat exchanger (300) is a plate heat exchanger.