WO2017088742A1

WO2017088742A1 - Water wall of supercritical circulating fluidized bed boiler having high flow stability at low load, and method of realizing low mass flow rate

Info

Publication number: WO2017088742A1
Application number: PCT/CN2016/106838
Authority: WO
Inventors: 徐鹏; 胡修奎; 巩李明; 陈震宇; 苏虎; 杨雪芬; 薛大勇; 聂立; 薛燕辉; 王鹏
Original assignee: 东方电气集团东方锅炉股份有限公司
Priority date: 2015-11-25
Filing date: 2016-11-23
Publication date: 2017-06-01
Also published as: CN105299634B; CN105299634A

Abstract

A water wall of a supercritical circulating fluidized bed boiler having high flow stability at a low load, and method of providing a low mass flow rate. The circulating fluidized bed boiler comprises a surrounding water wall (11) and a mid-partition water wall (17) of a furnace (1) having a low mass flow rate, and a working medium flows in the surrounding water wall (11) and the mid-partition water wall (17) connected in parallel. Tubes of the surrounding water wall (11) and the mid-partition water wall (17) have a greater inner diameter at locations having a steam content greater than 50% than locations having a steam content less than 50%, and the portion of the tubes having the greater inner diameter has a cross section area 1.05-3 times of a cross section area of the portion of the tubes having the smaller inner diameter. The water wall of the supercritical circulating fluidized bed boiler realizes a low mass flow rate, and addresses the problems of an increased water wall area and furnace height when the mass flow rate is low. In addition, the water wall of the supercritical circulating fluidized bed boiler addresses the problem of lower flow stability at a low load, thus preventing a negative feedback from happening in a water wall system.

Description

[Invention name established by ISA according to Rule 37.2] Water-cooling wall of supercritical circulating fluidized bed boiler with high flow stability under low load and method for realizing low mass flow rate

Technical field

The invention relates to a circulating fluidized bed boiler, in particular to a circulating fluidized bed boiler water wall system with supercritical parameters.

Background technique

The supercritical boiler generator set can obtain higher power generation efficiency. The supercritical circulating fluidized bed boiler refers to the pressure and temperature of the steam output from the boiler is higher than the critical parameter of water vapor (22.12MPa, 374.15 °C). However, in the supercritical state, there is no difference in physical parameters between water and steam, which results in the natural circulation (or forced circulation) water wall system of the steam drum-down pipe-water wall-fluclet used in the boiler below the subcritical parameter. . The supercritical boiler water wall system uses a primary DC boiler, that is, the working fluid (water or water vapor) in the water wall passes through the water wall once. The mass flow rate of the working fluid in the water wall is lower than that of the subcritical boiler natural circulation (or forced circulation), the water cooling wall tube is cooled by the working medium, the temperature of the water wall tube metal is higher, and the over temperature damage is prone to occur. problem.

The supercritical boiler water wall working fluid is once DC, the water wall working fluid outlet is superheated steam, and the furnace water wall is at different positions, such as the front wall water wall and the side wall water wall. Due to different positions and different lengths, the absorbed heat is different. It will cause the temperature of the working fluid in the water wall tube to be different, causing the temperature of the water wall material to be different. If the temperature difference is not controlled, in the bad case, the thermal stress will be cracked due to the temperature difference, and the water wall tube will be destroyed.

The water-cooled wall of the conventional supercritical pulverized coal boiler generally adopts the water-cooled wall structure of the "spiral coil", which reduces the flow area of the water-cooled wall tube, improves the mass flow rate of the working medium in the water-cooled wall tube, and simultaneously the spiral coil passes through the water-cooled wall in turn. Position, try to absorb heat evenly to solve the problem of water wall safety. The mass flow rate of the water wall of the ultra-supercritical pulverized coal boiler is generally greater than 1000 kg/m ² .s.

The circulating fluidized bed boiler has a large amount of circulating material in the furnace, and there is a large amount of adhering downflow material near the wall surface of the water wall. The spiral coil structure water wall is severely worn by the adhering downflow and cannot be used in a circulating fluidized bed boiler.

Based on the above reasons, the water cooling wall of the supercritical circulating fluidized bed boiler is arranged by a vertical pipe, and the mass flow rate of the water wall is generally low, generally less than 1000 kg/m ² .s, which is called “vertical pipe low mass flow rate”. The water-cooled wall system with low mass flow rate uses the "self-compensating property" of the working fluid to distribute the flow rate of the water wall, so that the heat-absorbing tube distributes more flow, enhances the tube cooling, and lowers the tube wall temperature.

However, the inventor of the present invention found in the research that the water-cooled wall of the supercritical CFB boiler with low mass flow rate has a serious problem of poor flow stability under low load: when the boiler is under low load operation, the flow rate of the water wall is reduced. The stability of the flow of the working fluid (water or steam, or a mixture of the two) in the water wall tube is reduced, and is disturbed, for example, external heating is enhanced, or the flow rate is reduced, and the flow velocity of the working medium is liable to change drastically, and the water is heated. Production The raw steam further blocks the waterwall tube, causing a decrease in flow, creating a negative feedback, which ultimately causes the wall temperature to rise.

Therefore, the design of the water-cooled wall of the supercritical CFB boiler with low mass flow rate needs to solve the stability problem of flow at low load and prevent the negative feedback from occurring. However, how to achieve the design of the water-cooled wall of supercritical CFB boilers with high flow stability under low load conditions under low-mass flow conditions is not disclosed.

In addition, the water-cooling wall of the super-critical CFB boiler with low mass flow rate adopts a primary-current boiler, that is, the working fluid (water or water vapor) in the water-cooling wall absorbs heat once through the water-cooling wall and is directly heated into superheated steam. This requires that the proportion of heat absorption of the water-cooled wall of the supercritical boiler (about 36-40%) increases the proportion of heat absorption of the critical water wall (less than 29%), and the water wall system must increase the area to meet the requirements. If no improvement measures are taken, the height of the boiler water wall will increase rapidly, resulting in an increase in boiler cost. In addition, the heat transfer in the furnace of the circulating fluidized bed boiler depends on the circulating materials. After the height of the furnace is increased, the circulating material concentration in the upper part of the furnace is reduced, and the heat transfer effect of the water wall is also reduced. Therefore, it is necessary to increase the area of the water wall of the supercritical circulating fluidized bed boiler, but does not cause a rapid increase in the height of the furnace.

In solving the problem of increasing the water wall area, there is a scheme in which the water wall and the expansion screen are connected in series in the prior art, which increases the screen type expansion heating surface in the furnace, reduces the furnace height, and reduces the boiler cost and manufacturing difficulty. However, this series structure has strict requirements on the dryness of the steam at the outlet of the water wall. For example, "under the 30% load condition of the boiler, the dryness of the working medium should be ≥80%" "Under the 50% load condition of the boiler, the water wall will be completed. The mass is heated to saturated steam." The above requirements must make the water wall still have enough area to make the furnace height reduction limited. In addition, the water wall and the expansion screen are connected in series, and the water wall system has a high mass flow rate, especially the mass flow rate of the expansion screen. The increase of the mass flow rate has a limited effect on reducing the temperature of the pipe wall, and also increases the resistance of the water wall, increases the energy consumption of the boiler feed water pump, and reduces the economic efficiency of the power plant.

Content of the invention

The object of the invention is that the water-cooling wall of the supercritical CFB boiler realizes a low mass flow rate, and at the same time solves the problem of increasing the water wall area and the furnace height under the low mass flow rate; in particular, the water-cooling wall of the supercritical CFB boiler which solves the low mass flow rate flows under a low load; The problem of stability degradation prevents the negative feedback of the water wall system from occurring.

The purpose of this patent is achieved by the following technical solutions:

A method for achieving a low mass flow rate in a water-cooled wall of a supercritical CFB boiler is as follows:

First, based on the steam flow (T) and fuel of the CFB boiler, the flue gas flow (Q) generated by the combustion is calculated, and then the cross-sectional area of the furnace is obtained from the flue gas flow rate and the flue gas flow rate in the furnace: the main elemental carbon in the fuel (C) Hydrogen (H) Sulfur (S) combustion releases heat and also produces flue gas. The amount of heat released and the amount of smoke produced are known from well-known chemical knowledge. The flue gas flow rate Q can be calculated based on the heat that the steam needs to absorb and the heat generated by the combustion of the fuel. The flow rate of the flue gas in the furnace is generally V=4-6m/s.Q/V=S, and S is the cross-sectional area of the furnace.

In the second step, the circumference (L) of the furnace is obtained according to the cross-sectional area of the furnace and the cross-sectional shape of the designed furnace; If a rectangular section furnace is selected, consider the ratio of the length (a) width (b) of the furnace of the circulating fluidized bed boiler, a*b=S, and determine a, b. Furnace circumference L = 2 * (a + b).

In the third step, according to the obtained furnace circumference (L), the inner diameter and the number of the water wall tubes constituting the furnace are selected according to the mass flow rate range of 700 to 350 kg/m ² .s, and the water wall of the furnace is separated by the surrounding water wall and the water cooling partition. The wall is connected in parallel:

The inner diameter of the surrounding water wall tube is r1, the number of water wall tubes around the wall is m1, the inner diameter of the water-cooling partition wall tube is r2, and the number of water-cooling partition walls is m2;

The flow area of the furnace wall is A=(3.14*r1 ² /4)*m1+(3.14*r2 ² /4)m2. The optimum range of the water wall mass flow rate t=T/At is 700-350kg/m ² .s, M1 and m2 should meet the requirements of the temperature of the flat wall of the water wall.

In the patented method, the number of water-cooled wall tubes m1 and the number of middle partition wall tubes m2 are too small, the flat steel is large in size, and the flat steel temperature will exceed the allowable value. The product of the inner diameter area and the number of water wall tubes is the flow area of the furnace wall. For optimum low mass flow rates, the optimum mass flow rate range is 700 to 350 kg/m ² .s. The mass flow rate is high. The water flow wall has different deviations in the flow rate of the working fluid, and the temperature difference of the outlet is large. Too low mass flow rate may also cause flow to stop, resulting in heat transfer deterioration. The low mass flow rate can be achieved by the above three steps of the patent, in particular the parallel arrangement of the surrounding water wall and the water cooled partition wall.

A water-cooling wall of a supercritical CFB boiler with high flow stability under low load, comprising a water-cooled wall and a water-cooled partition wall around the furnace with a low mass flow rate, and a concentrated down pipe and a connecting pipe, the working fluid flows in the surrounding water wall and water cooling The middle partition walls are connected in parallel. The feed water of the boiler is led to the surrounding water wall and the water-cooled partition wall by the concentrated down pipe, and then led to the mixing box by the connecting pipe, and the steam at the outlet of the collecting box is led to the downstream superheater. Moreover, the inner diameter of the water-cooled wall and the water-cooled partition wall of the furnace is larger than the inner diameter of the lower portion at a steam ratio of more than 50%, and the cross-sectional area of the large inner diameter portion of the tube is 1.05 to 3 times the cross-sectional area of the small inner diameter portion.

The supercritical circulating fluidized bed water wall system of the patented device comprises a surrounding water wall and a water cooled partition wall. Although the surrounding water wall and water-cooled partition walls are already used in boilers with small capacity, especially subcritical parameters. However, after the parameters of the boiler reach supercritical, the natural circulation (or forced circulation) water wall system consisting of the steam drum-down pipe-water wall-drum used in the boiler below the subcritical parameter cannot be adopted. The patented water-cooled wall and water-cooled partition wall are designed in parallel to solve the problem of increasing water wall area and furnace height under low mass flow rate. At the same time, due to the low mass flow rate design (the mass flow rate is generally less than 1000kg/m ² .s, especially 700-350kg/m ² .s), as described above, the inventor of the present invention finds that the surrounding water wall and the water-cooled partition wall The problem of low load flow stability unique to supercritical circulating fluidized bed boilers has emerged.

The conventional supercritical water wall diameter generally has a large inner diameter and a small inner diameter. This is because the upper working medium has a high temperature, and the use of a smaller inner diameter can increase the flow rate of the steam, enhance the cooling capacity of the pipe wall, and lower the wall temperature. In addition, the upper pipe diameter is smaller than the lower portion in order to increase the ability of the pipe to withstand internal pressure. The boiler designer knows that the smaller the pipe diameter, the smaller the required wall thickness under the same pipe internal pressure.

The inventors of the present patent found in the study that a supercritical circulating fluidized bed boiler with a low mass flow rate is different from a conventional boiler, and when the stability problem is solved, the conventional method cannot be used. The working fluid (water, steam or soda mixture) in the water-cooled wall and the water-cooled partition wall is heated during the flow, and the volume flow rate is increased as it is heated, in order to achieve a "self-compensating characteristic" of the low mass flow rate, Preventing the water from being heated and vaporized, the generated steam further blocks the water wall tube, causing the flow to decrease, and forming a negative feedback. The inventor of the present invention needs to change according to the specific volume of the working medium in the upper part of the surrounding water wall and the water cooling partition wall. Increase the inner diameter of the tube. That is, the inner diameter of the tube in the upper part of the water wall and the water-cooling partition wall around the furnace is larger than the inner diameter of the lower part. In addition, the position of the upper and lower pipe diameters of the surrounding water wall and water-cooled partition wall pipe should avoid the area where the working medium phase change (from water to steam), so the pipe is enlarged at a position where the steam ratio is more than 50%. path. And the cross-sectional area of the upper tube is 1.05 to 3 times the cross-sectional area of the lower tube.

Alternatively, there is no mixing or (and) dispensing device between the upper and lower portions of the water wall, water cooled partition wall pipe. This solution avoids stratification of the working fluid, uneven distribution of water and steam in the mixing or (and) dispensing device.

Alternatively, the water-cooled partition wall extends from the bottom of the furnace to the top. In this solution, in order to increase the heat exchange area of the water wall system, and at the same time not increase the boiler height, the cost is greatly increased. The surrounding water wall and the water cooling partition wall disclosed in this patent have many advantages. In the prior art expansion screen, if the height of the furnace of the supercritical circulating fluidized bed boiler is increased in the upper part of the furnace, the material concentration in the upper part of the furnace is lower, the heat transfer coefficient of the upper part is lowered, and the heat exchange efficiency of the expanded screen is low. To achieve the same amount of heat absorption, more material is needed. The water-cooled partition wall of the patent extends from the bottom of the furnace to the top, and a water-cooled partition wall is arranged in the middle and lower part of the furnace, and the heat transfer coefficient is high, which can save materials.

Alternatively, the water-cooled partition wall is disposed on the furnace water wall opposite to the furnace flue gas outlet passage, and the water-cooled partition wall is welded to the furnace water wall at the joint position. In this scheme, the water-cooled partition wall is arranged on the water wall of the furnace opposite to the flue gas outlet passage of the furnace, which is beneficial to the organized flow of the flue gas in the furnace to prevent irregular eddy currents and smoke wear and tear. The water-cooled partition wall and the surrounding water wall are welded and connected, which is beneficial to prevent vibration and deformation of the water-cooled partition wall.

Alternatively, the water-cooled partition wall is heated on both sides, and the inner diameter of the tube constituting the water-cooled partition wall is larger than the inner diameter of the tube constituting the water wall around the furnace. In this scheme, the water-cooled partition wall is in the furnace, and the pipe absorbs heat strongly. The preferred method is that the pipe diameter of the water-cooled partition wall is larger than the diameter of the surrounding water wall.

Alternatively, the inner diameter of the tube where the water wall around the furnace is bent to form the flue gas outlet passage is larger than the inner diameter of the tube at other locations. In this solution, there are many curved pipes in the upper part of the surrounding water wall, which cause a large flow resistance of the working fluid, such as a flue gas outlet, and the inner diameter of the pipe in these areas is larger than the inner diameter of the pipe at other positions.

Alternatively, the water-cooled partition wall has a different heating length, and the upper portion of the partition wall covers the refractory material for the tube having a short heat absorption length.

Alternatively, the width of the water-cooled partition wall does not exceed half the depth of the furnace. This program does not affect the organized flow of smoke in the furnace.

Alternatively, a plurality of water-cooled partition walls are arranged, and each water-cooled partition wall is symmetrically arranged on the furnace section. In this scheme, in order to increase the area of the water wall system, a plurality of water-cooled partition walls may be arranged in the furnace formed by the surrounding water wall, and when the water cooling partition wall is arranged in multiple places, it shall be symmetrically arranged in the furnace, which is favorable for uniform furnace temperature. .

Alternatively, a flue gas outlet passage is arranged on both sides of the furnace of the boiler, and a plurality of water-cooled partition walls are arranged between the flue gas outlet passages on both sides and arranged in a row, and a flue gas is left between the water-cooled partition walls. aisle.

The foregoing main scheme of the present invention and its further alternatives can be freely combined to form a plurality of schemes, all of which can be adopted and claimed in the present invention: as in the present invention, each option can be arbitrarily combined with other options, and those skilled in the art can It will be apparent from the prior art and common general knowledge that various combinations are possible after understanding the present invention, and are all technical solutions to be protected by the present invention, and are not exhaustive.

The invention has the beneficial effects that the water-cooling wall of the supercritical CFB boiler realizes a low mass flow rate, and at the same time solves the problem of increasing the water wall area and the furnace height under the low mass flow rate; in particular, solving the low-temperature flow rate supercritical CFB boiler water wall under low load The problem of reduced flow stability prevents the negative feedback of the water wall system from occurring.

DRAWINGS

1 is a schematic structural view of an embodiment of the present invention;

2 is a schematic view showing the arrangement structure of the water-cooled partition wall when the furnace flue gas outlet passage is arranged on both sides of the boiler;

In the figure, 1 is the furnace, 2 is the separation device, 3 is the economizer, 5 is the tail flue, 6 is the returning device, 8 is the water wall, 11 is the surrounding water wall, 14 is the sinking box, 16 is the concentration The down pipe, 17 is a water-cooled partition wall, 18 is a flue gas outlet passage, and 21 is a superheater.

detailed description

The present invention will be further described below in conjunction with the specific embodiments and the accompanying drawings.

In the second step, the circumference (L) of the furnace is obtained according to the cross-sectional area of the furnace and the cross-sectional shape of the designed furnace; if the rectangular section furnace is selected, the length (a) of the furnace of the circulating fluidized bed boiler is comprehensively considered. (b) Proportion, a*b=S, determine a, b. Furnace circumference L = 2 * (a + b).

Referring to Figure 1, a supercritical cycle boiler water wall system comprising a low temperature flow rate (the optimum mass flow rate range of 700 to 350 kg/m ² .s) is surrounded by a water wall 11 and a water cooled partition wall 17 The feed water of the boiler is led from the concentrated downcomer to the water wall 11 and the water cooled partition 17 around the furnace. The working medium is heated in the surrounding water wall 11 and the water-cooling partition wall 17, and the collecting box 14 is mixed by the connecting pipe. Under supercritical conditions, the steam at the outlet of the header tank 14 is directed to the downstream superheater 21. In order to meet the safety of the supercritical circulating fluidized bed boiler during low-load operation, the pressure fluctuation and the flow instability caused by the endothermic expansion of the working fluid in the water-cooled wall 11 and the water-cooled partition wall 17 around the furnace are prevented, and the water-cooled wall 11 is formed around the furnace. The inner diameter of the pipe in the upper part of the water-cooling partition wall 17 is larger than the inner diameter of the lower part, and the pipe diameter is increased at a position where the steam ratio is more than 50%, and the cross-sectional area of the upper pipe is 1.05 to 3 times the sectional area of the lower pipe.

The water-cooling partition wall 17 is disposed on the furnace water wall 11 facing the furnace flue gas outlet passage 18, and in the contact position, the water-cooling partition wall 17 is welded and connected to the surrounding water wall 11. This connection prevents the water-cooled partition wall 17 from vibrating. When the water-cooling partition wall 17 is heated on both sides, that is, the water-cooling partition wall 17 is placed in the furnace, and both sides are not connected and fixed to the surrounding water-cooling wall 11, and the inner diameter of the tube constituting the water-cooling partition wall 17 is larger than the composition furnace. The inner diameter of the tube surrounding the water wall 11.

The inner diameter of the tube around which the water-cooling wall 11 is bent to form the flue gas outlet passage 18 is larger than the inner diameter of the tube at other positions.

When the water-cooling partition wall 17 is different in heat length, the pipe having a short heat absorption length is covered with a refractory material in the upper portion of the water-cooling partition wall 17 to prevent the low load from being overheated due to the stagnation of the working medium.

In order to reduce the influence of the water-cooling partition wall 17 on the flow of the flue gas in the furnace, the width dimension B of the water-cooling partition wall 17 is preferably not more than 0.5 A, that is, not more than half of the depth of the furnace. When a plurality of water-cooling partition walls 17 are arranged, they are preferably arranged symmetrically on the section of the furnace, that is, symmetrically arranged left and right along the left and right side walls of the furnace or symmetrically arranged along the front and rear walls.

In another embodiment, when the furnace flue gas outlet passage 18 is disposed on both sides of the furnace of the boiler in the furnace chamber (such as the furnace flue gas outlet passage 18 disposed on the left and right sides of FIG. 2), the plurality of water-cooled partition walls 17 are arranged. Arranged in a row between the flue gas outlet passages 18 on both sides. In this case, there are more than 17 water-cooled partition walls, and a flue gas passage should be left between the water-cooled partition walls 17 to balance the flue gas pressure of the furnace.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. Within the scope.

Claims

A method for achieving a low mass flow rate in a water wall of a supercritical circulating fluidized bed boiler, characterized in that the steps are:

First, according to the steam flow rate T and the fuel of the circulating fluidized bed boiler, the flue gas flow rate Q generated by the combustion is calculated, and then the cross-sectional area of the furnace is obtained from the flue gas flow rate and the flue gas flow velocity V in the furnace S: Q/V=S ;

In the second step, according to the cross-sectional area of the obtained furnace, and the cross-sectional shape of the designed furnace, the circumference L of the furnace is obtained;

In the third step, according to the obtained furnace circumference L, the mass flow rate ranges from 700 to 350 kg/m 2 .s to select the inner diameter and the number of the water wall tubes of the furnace, and the water wall of the furnace is connected by the surrounding water wall and the water-cooled partition wall. Composition:

The inner diameter of the surrounding water wall tube is r1, the number of water wall tubes around the wall is m1, the inner diameter of the water-cooling partition wall tube is r2, the number of water-cooling partition wall tubes is m2; the flow area of the furnace water wall is A=(3.14*r1 2 /4)*m1+(3.14* r 2 /4) m2. The water wall mass flow rate t=T/A. and m1 and m2 should meet the requirements of the water wall flat steel temperature.
A water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load, comprising a water-cooled wall and a water-cooled partition wall surrounding the furnace with a low mass flow rate, and a concentrated down pipe and a connecting pipe, characterized in that: The flow is paralleled in the surrounding water wall and the water-cooled partition wall. The feed water of the boiler is led from the concentrated down pipe to the surrounding water wall and the water-cooled partition wall, and then the connecting pipe is led to the sinking box to mix and the steam at the outlet of the collecting box. Leading to the downstream superheater, and the inner diameter of the water wall and the water-cooling partition wall around the furnace is larger than the inner diameter of the lower part of the steam ratio greater than 50%, and the cross-sectional area of the large inner diameter part of the tube is the small inner diameter partial sectional area. 1.05 to 3 times.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 2, wherein the water-cooled partition wall is disposed on the water wall of the furnace facing the flue gas outlet passage of the furnace, In the connected position, the water-cooled partition wall is welded to the furnace wall.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 2, wherein the water-cooled partition wall is heated on both sides, and the inner diameter of the tube forming the water-cooled partition wall is larger than the water-cooling around the composition furnace. The inner diameter of the wall of the tube.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 1, wherein the inner diameter of the tube in the portion where the water wall is curved to form the flue gas outlet passage is larger than the inner diameter of the tube at other positions. .
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 1, wherein the water-cooled partition wall has different heating lengths, and the upper part of the partition wall has a short heat absorption length in the water cooling medium. The pipe is covered with refractory material.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 1, wherein the width of the water-cooled partition wall does not exceed half of the depth of the furnace.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 1, characterized in that: a plurality of water-cooled partition walls are arranged, and each water-cooled partition wall is symmetrically arranged on the furnace section.
The water-cooling wall of a supercritical circulating fluidized bed boiler with high flow stability under low load according to claim 1, wherein a flue gas outlet passage is arranged on both sides of the furnace, and a plurality of water-cooled partition walls are arranged at The flue gas outlet passages on both sides are arranged in a row, and a flue gas passage is left between the water-cooled partition walls.