CN114076301B - A linear vapor chamber steam boiler - Google Patents

Abstract

The invention provides a linear vapor chamber steam boiler, which includes an upper drum, a lower drum, and a riser and a downcomer connected between the upper drum and the lower drum. A uniform temperature plate extending from the center of the riser, the said uniform temperature plate includes a first linear wall and a second linear wall extending from the inner wall, the first linear wall and the second linear wall extend toward the direction of fluid flow, along the height direction , the inner wall of the riser is provided with multiple equal temperature panels, the intersection point is the vertical point on the inner wall, the line formed by the intersection point and the vertical point is the third line, the distance between the connection point of the first straight line wall and the inner wall and the vertical point is H, the riser The inner diameter of the pipe is R, and the distance S is designed as follows. The present invention conducts extensive research on the distance of the vapor chamber to achieve uniform temperature of the fluid, so as to achieve further uniform temperature, improve the service life of the product, avoid the problems of uneven mixing and increased flow resistance, and achieve optimal uniformity of the outlet fluid. warming effect.

Description

A linear vapor chamber steam boiler

technical field

The present invention is a project commissioned by colleges and universities to carry out research and development. The invention belongs to the field of steam generation, in particular to a steam boiler, and belongs to the field of IPC classification number F22.

Background technique

The circuit that receives heat from the furnace and makes the fluid flow from a low level to a high level is called an "ascending loop", while the circuit that receives heat and makes a fluid flow from a high level to a low level is called a "falling loop". A circuit consists of a pipe or a group of pipes leading from a common point, such as a header or steam drum, and terminating at a common point, also a header or drum.

In most natural circulation boiler designs, the heated tubes making up the evaporating section generally provide upward flow, but in multi-drum boilers, the descending heated tubes of the evaporator bundle do not. In this type of boiler, the descending receiver tubes provide the entire circulation flow to the furnace and riser tubes in the evaporator bundle section.

On the one hand, the fluid in the riser is generally a vapor-liquid two-phase flow during the upward process, so that the fluid in the riser is a mixture of vapor and liquid. The existence of the vapor-liquid two-phase flow affects the heat absorption efficiency of the riser.

The riser tube is heated unevenly by each part, for example, the temperature on the side close to the furnace is high, and the temperature on the side away from the furnace is low, because the temperature of the fluid in different positions inside the riser tube is different, because the temperature difference will lead to uneven temperature in the riser tube Lead to overheating or overcooling, affecting operation.

Aiming at the above problems, the present invention improves on the previous invention, and provides a new steam boiler, thereby solving the problem of uneven fluid temperature in the riser.

Contents of the invention

The present invention provides a new steam boiler so as to solve the previous technical problems.

In order to achieve the above object, the technical scheme of the present invention is as follows:

A steam boiler, comprising an upper drum, a lower drum, and a riser and a downcomer connected between the upper drum and the lower drum, characterized in that the interior of the riser extends from the inner wall of the riser to the center of the riser The uniform temperature plate includes a first linear wall and a second linear wall extending from the inner wall, the first linear wall and the second linear wall extend toward the direction of fluid flow, along the height direction, the inner wall of the riser A plurality of temperature chambers are set, the intersection point is a vertical point on the inner wall, and the line formed by the intersection point and the vertical point is the third line, wherein the acute angle formed by the first straight wall and the inner wall is smaller than the acute angle formed by the second straight wall and the inner wall, and the first The straight wall and the second straight wall extend towards the direction of fluid flow, the intersection of the first straight wall and the second straight wall is located at the upper part of the connection between the first straight wall and the inner wall, and at the same time it is located at the junction of the second straight wall and the inner wall upper part. The shape of the vapor chamber is formed by rotating the first straight wall, the second straight wall and the inner wall along the axis of the riser.

Preferably, the first straight wall at the intersection position forms an included angle of 30-60° with the axis of the riser.

Preferably, the total arc of the arc connecting the uniform temperature plate and the inner wall of the same layer is 150-180°.

Compared with the prior art, the present invention has the following advantages:

1) The present invention provides a new steam boiler. By setting a linear vapor chamber in the riser tube, a part of the fluid flows along the vapor chamber and guides to the opposite direction, and is fully mixed with the fluid entering in the opposite direction, thereby realizing fluid The temperature is uniform in order to achieve further temperature uniformity and improve the service life of the product.

2) The present invention has conducted extensive research on the distance of the uniform temperature plate, and designed the formula of the minimum distance, which fully meets the needs of uniform temperature mixing, avoids the problems of uneven mixing and increased flow resistance, and achieves the optimal uniform temperature of the outlet fluid Effect.

3) The present invention conducts extensive research on the heat transfer laws caused by the changes of various parameters of the vapor chamber. Under the condition of satisfying the flow resistance, the present invention optimizes the structure of the vapor chamber of the heat exchanger to achieve the optimal Outlet fluid uniform temperature effect.

4) In the present invention, through reasonable layout, adjacent rows of vapor chamber structures are staggered, so as to further fully mix fluids and achieve uniform temperature.

5) The present invention further promotes sufficient mixing by setting distribution changes of parameters such as the size and quantity angle of the vapor chamber along the fluid flow direction.

Description of drawings

Fig. 1 is a schematic structural view of the steam boiler of the present invention.

Fig. 2 is a schematic diagram of another embodiment of the steam boiler structure of the present invention.

Fig. 3 is an axial sectional view of a riser provided with a vapor chamber in the present invention.

Fig. 4 is a schematic diagram of the size of the riser provided with a vapor chamber in the present invention.

Fig. 5 is a three-dimensional schematic diagram of setting a uniform temperature plate on each floor.

Fig. 6 is a three-dimensional schematic diagram of setting three equal temperature plates in each layer.

Fig. 7 is a three-dimensional schematic diagram of setting a uniform temperature plate on each floor.

FIG. 8 is an exploded perspective view of one side of the riser in FIG. 7 .

In the figure: 1. Upper drum, 2. Lower drum, 3. Riser, 4. Even temperature plate, 5. Downer, 6. Downer, 7. Lower drum, 8. Rising tube, 9. Rising tube, 10 Furnace combustion Chamber, 11 outlet header, 12 flue; 41 first straight wall, 42 second straight wall, 43 intersection.

Detailed ways

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

In this article, if there is no special explanation, when it comes to formulas, "/" means division, and "×" and "*" mean multiplication.

A steam boiler as shown in FIG. 1 includes an upper drum 1 and a lower drum 2 , and the ascending tube 3 and the downcomer 5 connect the upper drum 1 and the lower drum 2 . Water enters the downcomer 5 from the upper drum 1 . The water flows down in the downcomer and is collected in the lower drum 2. The riser 3 of the boiler is heated by the combustion of fuel in the combustion chamber 10 of the furnace. The heat absorbed by the riser 3 causes the liquid inside the tube to boil, thereby creating a two-phase mixture of water and steam. The two-phase mixture in the riser 3 reaches the upper drum 1 . The supercooled water released from the water supply pipe (not shown) in the upper drum 1 and the saturated liquid discharged from the separation device are mixed together to form a supercooled liquid, and the supercooled liquid flows out of the upper drum 1 and enters the downcomer 5, in this way The process completes a flow cycle.

As further shown in FIG. 2 , another embodiment of the steam boiler includes an upper drum 1 and a lower drum 2 , and the riser tube 3 and the downcomer 5 connect the upper drum 1 and the lower drum 2 . Water enters the downcomer 5 of the heated evaporation tube bundle in the exhaust flue 12 in the furnace from the upper drum 1 . The water flows down in the downcomer and is collected in the lower drum 2. Since the downcomer 5 has absorbed heat, the temperature of the water entering the lower drum 2 increases. Depending on how much heat is absorbed, the water in the lower drum 2 can be subcooled or saturated. Part of the fluid (generally steam-water mixture) leaving the lower drum 2 flows upward into the riser 3 of the evaporator tube bundle. The liquid flowing upward into the riser 3 absorbs heat and enters the upper drum 1 .

A part of the fluid leaving the lower drum 2 reaches the furnace lower drum 7 through the downcomer 6 . Liquid entering a lower drum 7 is distributed to furnace tubes 8 connected to the lower drum 7 . The furnace tubes are heated by the combustion of fuel in the furnace combustion chamber 10 . The heat absorbed by the furnace tubes 8 boils the liquid in the furnace tubes 8, thereby creating a two-phase mixture of water and steam. The two-phase mixture in the furnace tube 8 reaches the upper drum 1 through the furnace tube 8 directly connected to the upper drum 1, and the furnace tube 8 at this time is also the rising tube, or between the lower drum 7 and the upper drum 1 An outlet header 11 is provided to convey the two-phase mixture from the outlet header 11 of the furnace circuit to the upper drum 1 through the intermediate riser 9 . The internal separation device in the upper drum 1 separates the two-phase mixture into steam and water. The supercooled water released from the water supply pipe (not shown) in the upper drum 1 and the saturated liquid discharged from the separation device are mixed together to form a supercooled liquid, and the supercooled liquid flows out of the upper drum 1 and enters the downcomer 5, in this way The process completes a flow cycle.

For the evaporator tube bank of the steam boiler, the selected furnace wall and convection furnace wall which are scoured by the combustion air flow, it is required to ensure a critical input heat so that the fluid can fully circulate upward in all the tubes in the tube bank and convection furnace wall circuit without causing flow instability.

As an improvement, as shown in FIG. 3 , the riser 3 and/or riser 8 and/or riser 9 are provided with a vapor chamber 4 extending from the riser inner wall 51 to the center of the riser. 4 includes a first straight wall 41 and a second straight wall 42 extending from the inner wall, wherein the acute angle formed by the first straight wall 41 and the inner wall is smaller than the acute angle formed by the second straight wall 42 and the inner wall, the first straight wall 41 and the inner wall The second straight wall 42 extends towards the direction of fluid flow, the intersection 43 of the first straight wall 41 and the second straight wall 42 is located downstream of the joint between the first straight wall 41 and the inner wall 51 , and is located at the same time as the second straight wall 42 and the inner wall downstream of the connection. The shape of the temperature chamber 4 is the shape formed by the rotation of the first linear wall 41 , the second linear wall 42 and the inner wall along the axis of the riser.

The present invention provides that by setting a uniform temperature plate in the riser, a part of the fluid flows along the uniform temperature plate and guides to the opposite direction, and is fully mixed with the fluid entering in the opposite direction, so that the temperature of the fluid is uniform, so as to meet the needs of further heat exchange , improve product life. Moreover, by setting the second straight wall, and the inclination of the second straight wall is small, the fluid diverted from the opposite direction can also rotate along the direction of the second straight wall, increasing buffering and reducing flow resistance.

The temperature chamber of the present invention is respectively provided with a first straight wall and a second straight wall, and by arranging the two straight walls, the disturbance effect of the fluid is better, and the area of the temperature chamber in contact with the inner wall is increased, thereby increasing the stability.

The rising pipe mentioned later is at least one of the rising pipe 3 , the rising pipe 8 and the rising pipe 9 .

Preferably, the first straight wall 41 at the position of intersection 43 forms an included angle of 30-60° with the axis of the riser pipe, preferably the included angle is 45°. By setting this included angle, the fluid can be quickly guided to the opposite downstream position, and the flow resistance can be further reduced.

Preferably, as shown in FIG. 3 , along the height direction, multiple layers of vapor chambers 4 are arranged on the inner wall of the riser, and the vapor chambers of adjacent layers are staggered. Through the staggered distribution of adjacent rows of equal temperature plates, the fluids can fully move to the opposite position in the riser pipe to ensure full mixing and uniformity. For example, as shown in Figures 3, 5, and 7, there is one vapor chamber for each layer, and the total arc of this one is 150-180°. Of course, multiple vapor chambers can be installed on each layer. For example, the total arc of three chambers in each layer in Figure 6 is 150-180°.

Preferably, the distance between the intersection point and the inner wall of the riser is 0.3-0.5 times, preferably 0.4 times, the diameter of the riser. Through this setting, the air has less flow resistance on the basis of thorough mixing.

Preferably, the length of the first straight wall is greater than the length of the second straight wall.

Preferably, the total arc of the arc connecting the uniform temperature plate and the inner wall of the same layer is 150-180°. This parameter setting ensures adequate mixing while meeting resistance requirements. For example, there is one vapor chamber for each layer shown in Figure 2, and the total arc of this one is 150-180°. Of course, multiple vapor chambers can be installed on each layer, for example, the total arc of 3 chambers is 150-180°.

As a preference, there are multiple vapor chambers on the A layer, intervals are set between the A chambers, and the A chambers are arranged at equal intervals. The B layer is the adjacent layer of the A layer. Viewed from the flow direction, the B layer is set At the interval position of layer A. The positions of the equal temperature plates in adjacent layers are complementary, so that the fluids can fully move to the opposite positions in the riser pipe, ensuring full mixing and uniformity. It should be noted that layer A and layer B here do not specifically designate that layer, and A and B are only used as a difference, and they are distinguished as adjacent layers.

Preferably, along the height direction, a plurality of temperature chambers are arranged on the inner wall of the riser, and along the height direction, the distribution density of the temperature chambers becomes smaller and smaller. Because with the continuous movement of the fluid, the mixing degree of the fluid is getting better and better, so it is necessary to set the distribution density to be smaller and smaller to reduce the flow resistance. In the degree of resistance reduction and material cost saving, the temperature uniformity effect achieve basically the same effect.

Preferably, along the height direction, the distribution density of the temperature chamber is gradually increasing with decreasing distribution density. The above effect is the result of a large number of numerical simulations and experimental studies. It is found through research that this law conforms to the law of fluid motion, and the temperature equalization effect achieves basically the same effect to the extent that resistance is further reduced and material costs are saved.

Preferably, along the height direction, a plurality of temperature chambers are arranged on the inner wall of the riser, and along the height direction, the size of the temperature chambers becomes smaller and smaller. Because with the continuous movement of the fluid, the mixing degree of the fluid is getting better and better, so the setting size needs to be smaller and smaller to reduce the flow resistance. In the degree of resistance reduction and material cost saving, the temperature uniformity effect can reach Basically the same effect.

Preferably, along the height direction, a plurality of temperature chambers are arranged on the inner wall of the riser, and along the height direction, the size of the temperature chambers becomes smaller and larger. The above effect is the result of a large number of numerical simulations and experimental studies. It is found through research that this law conforms to the law of fluid motion, and the temperature equalization effect achieves basically the same effect to the extent that resistance is further reduced and material costs are saved.

Through a large number of numerical simulations and experimental studies, it is found that the angle and size of the uniform temperature plate have a great influence on heat transfer and uniform mixing. If the size of the plates is too large, the flow resistance will be affected. If the included angle is too large, the effect of agitating the fluid will be poor, the resistance will become larger, and the mixing effect will be worse. It leads to increased movement resistance, so the present application has obtained the latest optimization relationship of the structure size of the chamber through a large number of data simulations and experiments.

Preferably, the length L2 of the first straight wall, the length L1 of the second straight wall, the acute angle between the first line and the inner wall is A2, the acute angle between the second line and the inner wall is A1, and the same side is adjacent to each other along the direction of fluid flow. The spacing S of the temperature plate structure, that is, the distance between the center points of the inner walls of adjacent temperature chambers, the center point is the midpoint of the connection point between the first straight wall, the second straight wall and the inner wall, and meets the following requirements :

N=a-b*Ln(M), where N=(L1+L2)/S, M=sin(A2)/sin(A1); Ln is a logarithmic function,

0.3218<a<0.3230, 0.1284<b<0.1286;

Preferably, 0.25<M<0.75, 0.34<N<0.44, 45<A1<75°, 15<A2<65°, 350<S<500mm, 70<L2<130mm, 30<L1<90mm.

The optimal design requirements of the chamber structure can be carried out from the above formulas. The above-mentioned structural optimization formula is a major improvement point of the present invention, and is the most unique optimization formula obtained through a large number of numerical simulations and experimental studies, and is not common knowledge in the field.

More preferably, a=0.3219, b=0.1285.

As a preference, when the angle formed by the rising pipe and the horizontal plane is A, the correction coefficient c can be added to correct the data, namely

c* N=ab*Ln(M); c=1/sin(A) ^m , wherein 0.09<m<0.11, preferably m=0.10.

20°<A<80°, preferably 40-60°.

In the data simulation and experiment, it is found that the distance between the chambers must be greater than a certain distance, otherwise the fluid will be guided to the opposite direction through the previous chamber, but if the distance between the chambers is too small, the fluid will The flow on the opposite side has not yet fully filled the entire pipeline. At this time, setting the vapor chamber will not achieve the mixing effect. The vapor chamber only acts as a baffle plate and does not guide the mixing. It can only increase the flow resistance. Therefore, through a lot of research, the present application proposes a design scheme for the minimum space between the chambers, which has certain guiding significance for the design of such chambers.

The intersection point 43 is the vertical point on the inner wall, the line formed by the intersection point and the vertical point is the third line, the distance between the connection point of the first straight line wall and the inner wall and the vertical point is H, the inner pipe diameter of the riser is R, and the distance S is adopted Designed as follows:

S>=a*H+b*((H) ² +R ² ) ^(1/2) ;

，1.432<c<1.443，where 2.38<a<3.18,

, 1.432<c<1.443,

As preferred, a=2.78, c=1.437;

The present invention obtains the minimum design distance of the vapor chamber through a large number of experiments and numerical simulations, and the above design distance reduces resistance and enables sufficient mixing.

As a preference, when the angle formed by the rising pipe and the horizontal plane is A, the correction coefficient d can be added to correct the data, that is

S/d>=a*H+b*((H) ² +R ² ) ^(1/2) ; d=sin(A) ⁿ , wherein 0.093<n<0.105, preferably n=0.099.

Preferably, along the direction of fluid flow, the diameter of the riser pipe 3 increases continuously. The main reasons are as follows: 1) By increasing the diameter of the ascending pipe, the flow resistance can be reduced, so that the evaporated gas in the ascending pipe will continuously move towards the direction of increasing pipe diameter, thereby further promoting the circulation flow of the loop heat pipe. 2) Because with the continuous flow of the fluid, the liquid evaporates continuously in the riser, which makes the volume of the gas larger and larger, and the pressure is also higher and higher. Therefore, the increasing diameter of the pipe is used to meet the increasing volume of the gas and The change in pressure, so that the overall pressure distribution is uniform. 3) By increasing the pipe diameter of the riser, the impact phenomenon caused by the increase in the volume of the gas outlet can be reduced.

Preferably, along the direction of fluid flow, the diameter of the riser pipe 3 increases continuously to a larger extent. The change in the amplitude of the above-mentioned tube diameter is the result obtained by the applicant through a large number of experiments and numerical simulations. Through the above-mentioned setting, the circulation flow of the loop heat pipe can be further promoted, the overall uniform pressure can be achieved, and the impact phenomenon can be reduced.

Preferably, the diameter of the ascending pipe is larger than that of the descending pipe. The main purpose is to increase the resistance of the descending pipe and reduce the resistance of the ascending pipe, making it easier for the steam to flow from the evaporator, and the loop heat pipe can form a better circulation.

Preferably, the diameter of the downcomer decreases continuously along the direction of fluid flow. The main reasons are as follows: 1) With the continuous flow of the fluid, the steam is continuously condensed in the downcomer, so that the volume of the fluid becomes smaller and the pressure becomes smaller and smaller, so the pipe diameter is reduced to meet the increasing fluid volume. The volume and pressure changes, so that the overall pressure distribution is uniform and the heat transfer is uniform. 2) By reducing the pipe diameter of the heat-absorbing pipe, materials can be saved and costs can be reduced.

Preferably, along the direction of fluid flow, the diameter of the downcomer decreases continuously and becomes larger and larger. The change in the amplitude of the above-mentioned tube diameter is the result obtained by the applicant through a large number of experiments and numerical simulations. Through the above-mentioned setting, the circulation flow of the loop heat pipe can be further promoted, and the overall pressure uniformity can be achieved.

Although the present invention has been disclosed above with preferred embodiments, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, so the protection scope of the present invention should be based on the scope defined in the claims.

Claims (3)

1. A linear temperature-uniforming plate steam boiler comprises an upper boiler barrel, a lower boiler barrel, a rising pipe and a descending pipe which are connected between the upper boiler barrel and the lower boiler barrel, and is characterized in that a temperature-uniforming plate extending from the inner wall of the rising pipe to the center of the rising pipe is arranged in the rising pipe, the temperature-uniforming plate comprises a first linear wall and a second linear wall which extend from the inner wall, wherein an acute angle formed by the first linear wall and the inner wall is smaller than an acute angle formed by the second linear wall and the inner wall, the first linear wall and the second linear wall extend towards the fluid flow direction, the intersection point of the first linear wall and the second linear wall is positioned at the upper part of the connection part of the first linear wall and the inner wall and is positioned at the upper part of the connection part of the second linear wall and the inner wall, and the shape of the temperature-uniforming plate is the shape formed by the first linear wall, the second linear wall and the inner wall rotating along the axis of the rising pipe; a layer temperature-uniforming plate sets up the polylith, sets up the interval between the A layer temperature-uniforming plate, and A layer temperature-uniforming plate is the equidistant setting, and B layer is the adjacent layer on A layer, observes from the direction of flow, and B layer temperature-uniforming plate sets up the interval position department on A layer.

2. A steam boiler according to claim 1, characterized in that the first rectilinear wall forms an angle of 30-60 ° with the axis of the riser at the point of intersection.

3. A steam boiler according to claim 1, characterized in that the total arc of the arcs connecting the temperature-equalizing plates of the same layer with the inner wall is 150-180 °.

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