RU2490550C2 - Method for supply and heating of steam - Google Patents

Abstract

FIELD: heating.

SUBSTANCE: method for supply and heating of steam consists in production of steam in process of heating of a steam-generating liquid with subsequent reheating of the produced steam during its contact with the heated heat-exchange coarse-dispersed material, besides, the steam-generating liquid, preferably, water, is filled into a reservoir, which is formed by means of installation, preferably, axisymmetric one, of a shell with a bottom on a stack, at the same time the heat exchange material is placed into the specified reservoir, preferably, stones, hot smoke gases are sent via the specified stack, preferably, stove combustion products, and thus the steam-generating liquid is heated with the heat-exchange material to the temperature of steam formation, at the same time steam produced from heating of the steam-generating liquid and related moist air, which create a steam and air mixture, is sent preferably along the stack, into a circular gap, which is formed between the reservoir cover and the stack, and further into circular cavities, inner and outer ones, which are formed by installation in the upper part of the stack jacket, made of two shells - inner and outer ones, and two profiled perforated bottoms installed at the ends of the specified shells, at the same time the heat-exchange material is placed in the outer cavity of the specified jacket.

EFFECT: increased heat emission of fuel combustion products, increased time of stove operation with invariable fuel consumption, possibility to produce heated steam with controlled temperature and moisture.

8 cl, 3 dwg

Description

The invention relates to the design of furnaces and a method for generating superheated steam and can be used in the equipment of stationary and mobile types of baths, as well as for heating domestic and industrial premises.

Known furnace for a bath containing a metal body, a furnace, a chamber with stones located in it and a chimney mounted above the chamber. During operation, clean steam is obtained by pouring hot water on the stones (Patent RU No. 2005263 C1, IPC F24B 1/24, 03/07/1993).

The disadvantage of these furnaces is the possibility of flue gases entering the steam room and the presence of large drops of boiled water brought up to 70% in relative humidity. However, it is impossible to obtain superheated steam with a relative humidity of less than 25%.

Known methods for producing superheated steam from high-pressure wet steam by separating the liquid from the steam, throttling and overheating due to heat exchange with saturated steam and thereby increase efficiency (USSR AS 561048 A, IPC F22G 1/10, 08/01/1977).

The disadvantage of this method is the need for an additional steam generator and the difficulty of stabilizing the temperature of superheated steam.

Known furnace for a bath containing a metal case with a furnace, chimney and an open container with heat-exchange coarse material, wherein said open container is placed in the upper part of the fire chamber from the side of the heated room, an increased pressure vessel with a heat-exchange coarse material and installed in its upper is placed in the fire chamber part of the moisture distributing device connected to the tank for the vaporizing liquid by means of a dispenser, a throttle tube is built in from the bottom to the top of the indicated tank a, passing through the heat-exchange coarse material and the upper part of the furnace into the indicated open container, which provides additional overheating of the superheated steam formed in the increased pressure vessel in the upper part of the furnace and due to regenerative heat exchange with coarse material (RF Patent No. 2250417, IPC F24B 1/00, 5/00).

The specified furnace operates as follows.

Fuel is laid in the furnace of the metal case of the modification in question through the door and ignited. Residues from combustible fuel wake up through the grate to the blower. Hot gas generated from the combustion of fuel rises up the furnace, heats the coarse heat-exchanging coarse material in the tank and container, as well as steam in the upper part of the throttle pipe. Then the hot gas, rising up through the through chimney, heats the water tank. Gradually, the coarse-grained material 7 is heated to (350-450) ° C, heating the air in the room to (60-100) ° C.

The method of steam overheating, implemented using the specified furnace, is as follows.

To obtain superheated steam, the vaporizing liquid from the tank through the throttle channel with the pipe enters the moisture distribution device. The heating of the liquid occurs when it comes in contact with a heat-exchange coarse-grained material. The resulting saturated steam rises to the top of the tank and then, as its volume increases, it seeps through coarse-grained material under its own pressure, heats more than 100 ° C and enters the inlet of the throttle pipe in the lower part of the tank. Next, superheated steam is heated in a horizontal section of the throttle pipe in the upper part of the furnace. The throttled steam enters an open container and, in the process of recuperative heat exchange with coarse material, overheats above 110 ° C, heating the room.

The disadvantage of this furnace is the need for an additional moisture distribution device and the difficulty of stabilizing the temperature of superheated steam.

The objective of the invention is to remedy these shortcomings and create a method for the formation and heating of steam, the use of which will increase the heat transfer of the combustion products of the fuel and significantly increase the operating time of the furnace with constant fuel consumption with the possibility of obtaining superheated steam with controlled temperature and humidity.

The solution of this problem is achieved due to the fact that in the proposed method of generating and heating steam, which consists in producing steam by heating a vaporizing liquid, followed by overheating of the obtained steam when it comes in contact with a heated heat-exchange coarse material, according to the invention, the vaporizing liquid, mainly water, is poured into the tank, which is formed through the installation, mainly axisymmetrically, on the chimney of the shell of the shell with the bottom, while in the said tank is placed heat exchange material, mainly stones, pass through the specified pipe hot flue gases, preferably combustion products of the furnace, and thereby heat the vaporizing liquid with the heat exchange material to the temperature of steam formation, while the vapor obtained by heating the vaporizing liquid and humidified air, forming a vapor-air mixture direct, mainly along the pipe, into the annular gap, which is formed between the lid of the tank and the chimney, and then into the annular cavity, internal and external, to which form by installing in the upper part of the pipe a casing, consisting of two shells - internal and external, and two profiled perforated bottoms installed from the ends of the said shells, while the heat exchange material is placed in the outer cavity of the said shell.

In an embodiment, the upper profiled bottom of the casing is made with the possibility of changing its bore, which allows you to adjust the flow of steam.

In an application of the method, the inner diameter d _{n of the} inner shell of the casing is performed in the ratio d _nn ≈ (1.1 ... 1.5) D _tp , and the inner diameter d _{n of the} outer shell of the casing is performed in the ratio d _n ≈ (1.1 ... 2 ) d _vn , while the thickness s of the pipe walls, inner and outer shells of the body is selected in the ratio s≈ (0.04 ... 0.12) D _tr , where: d _vn is the inner diameter of the inner shell of the casing, d _n is the inner diameter of the outer shell shells, D _TP - the inner diameter of the pipe.

In an embodiment, the inner diameter d _{n of the} inner shell of the casing is d _n ≈ (1.1 ... 1.5) D _tr , and the inner diameter d _{n of the} outer shell of the casing is d _n ≈ (1.1 ... 2) d _vn , at the thickness s of the walls of the pipe, the inner and outer shells of the casing is s≈ (0.04 ... 0.12) D _tp , where: d _int is the inner diameter of the inner shell of the casing, d _n is the inner diameter of the outer shell of the casing, D _tp is the inner pipe diameter.

The lower limit of the ratio d _int ≈ (1.1 ... 1.5) D _{tr is} selected based on the fact that with a further decrease in it, the resistance of the path formed by the inner shell and pipe increases, which leads to a decrease in the efficiency of the furnace.

The upper limit of the specified ratio is selected based on the fact that with a further increase in it, there is a decrease in the speed of steam passing through the specified gap, which leads to a deterioration in heat transfer conditions, and, accordingly, a decrease in the efficiency of the furnace.

The lower limit of the ratio d _n ≈ (1.1 ... 2) d _{vn is} selected based on the fact that with a further decrease in it, the resistance of the path formed by the inner shell and the outer shell increases, which reduces the efficiency of the furnace.

The upper limit of the specified ratio is selected based on the fact that with a further increase in it, there is a decrease in the speed of steam passing through the specified gap, which leads to a deterioration in heat transfer conditions, and, accordingly, a decrease in the efficiency of the furnace.

In addition, its further increase leads to a deterioration in the mass-dimensional characteristics of the furnace.

The lower limit of the ratio s≈ (0.04 ... 0.12) D _{tp is} chosen based on the fact that with a further decrease in it, the stability and shape of the structural elements of the furnace are lost, and with an increase in the upper limit above the specified thermal inertia of the structure increases, the time increases heating and heat transfer conditions between metal parts, combustion products and steam are getting worse.

In an application of the method, the inner diameter of the container for the vaporizing liquid is performed in the ratio d _em ≈ (1.8 ... 3.0) D _tr , preferably 2 D _tr , where: d _em is the internal diameter of the tank for the vaporizing liquid, D _tr is the internal pipe diameter.

The lower limit of the ratio d _em ≈ (1.8 ... 3.0) D _{tp is} chosen based on the fact that with its further decrease, almost instantaneous boiling and evaporation of the vaporizing liquid occurs, which affects the operational performance of the furnace, and the increase in the inner diameter of the tank for vaporizing liquid above the specified upper limit leads to an increase in the preparation time of the furnace for operation due to the need to heat a sufficiently large volume of water and to the deterioration of the mass-dimensional characteristics of the furnace.

In an application of the method, the lower bottom of the casing is installed from the lid of the tank with a vaporizing liquid, preferably an annular gap, between the lid and the pipe at a distance h≈ (0.01 ... 0.5) D _tr , where h is the distance from the lid of the tank to the lower bottom casing, D _Tr - the inner diameter of the pipe.

The lower limit of the ratio h≈ (0.01 ... 0.5) is chosen based on the fact that with a further decrease in it, there is an increase in the path resistance and a redistribution of the flow of steam going into the annular gap between the pipe wall and the inner shell and into the annular gap between inner and outer shells. The increase in the annular gap above the specified upper limit leads to the deterioration of the conditions of vaporization in the annular tank and the deterioration of the mass-dimensional characteristics of the furnace.

In an application of the method, a shutter is installed in the upper output part of the pipe with the possibility of changing the bore of the pipe, which will allow you to adjust the draft and, accordingly, change the modes of the fuel combustion in the furnace.

In an application of the method, the outer diameter of the annular gap between the lid of the vapor-forming tank is performed by not more than 1.5 D _tr , where D _tp is the inner diameter of the pipe.

The indicated value was chosen on the basis that, with its further increase, a sharp deterioration in the conditions of vaporization in the annular tank occurs.

In an application of the method, the length of the casing is performed in the following limits: L≈ (1 ... 12) D _tp , where L is the length of the casing, D _tp is the inner diameter of the pipe.

The lower limit of this ratio is chosen on the basis that, with a further decrease in it, the steam supplied to the annular gaps of the casing will not have time to warm up sufficiently and take away heat from the exhaust products of combustion, which will lead to a decrease in the efficiency of the furnace. The upper limit of the specified ratio is selected based on the fact that with a further increase in it, the heat exchange between the exhaust products and the steam decreases due to a decrease in the temperature of the products of combustion, and unheated steam or steam that has already given off the received heat will enter the room, which will lead to deterioration the efficiency of the furnace. In addition, a further increase in the specified limit leads to a deterioration in the mass-dimensional characteristics of the furnace.

The invention is illustrated by drawings, where figure 1 shows a longitudinal section of a chimney for implementing the proposed method, figure 2 is the bottom of the casing, top view, figure 3 is a perspective view of the chimney, indicating the distribution of steam and product flows combustion.

The proposed method can be implemented using a sauna stove with a chimney of the following design.

The chimney for the furnace contains a vertically oriented housing 1. The lower inlet part 2 of the housing 1 is connected to a source of hot gases, preferably fuel combustion products in the furnace, and the upper outlet 3 to the surrounding atmosphere. In the lower part 2 of the pipe body 1, a shell 4 with a bottom is installed, forming with the pipe body 1 an annular container 5 for vaporizing liquid, mainly water and heat exchange material. The upper output part of the tank 5 is closed by a cover 6 made in the form of a truncated cone. An annular gap 7 is made between the lid 6 and the pipe body 1. A cylindrical casing 8 is installed above the container 5, in the immediate vicinity of it, coaxially with the pipe body 1, consisting of two shells - internal 9 and external 10, installed coaxially with an annular radial clearance in relation to the pipe body and to each other. The annular radial gaps 11 and 12 between the pipe body 1 and the inner shell 9 and between the inner 9 and the outer 10 shells are respectively connected to the inner cavity of the annular water tank 5 through said annular gap 7 between the cover 6 and the pipe body 1. The casing 8 is closed from the ends profiled perforated bottoms 13 and 14, and the bottom 14 can be made with the possibility of changing its bore. In the upper part 3 of the housing 1, a shutter 15 is rotatably mounted. In the cavity of the annular container 5 and in the annular gap 12 between the inner 9 and the outer shells 10, coarse heat-exchanging material 16 is laid.

The proposed method is implemented as follows.

The flow of combustion products obtained in the furnace of the furnace and having a high temperature is directed to the lower inlet part 2 of the pipe body 1, where it rises due to the thrust up to the output part 3, while heating the chimney body 1. A vapor-forming liquid, mainly water, is poured into the cavity of the container 5, formed by the shell 4 with the bottom, with the coarse-dispersed heat-exchange material 16 previously laid.

Due to convective heat transfer between the hot wall of the lower part 2 of the housing 1 and the water poured into the annular container 5, the water is heated to the temperature of vaporization, after which steam is formed while moistening the air in the zone of the lid 6. The resulting air-vapor mixture, consisting of steam and humidified air, and having a heat capacity higher than ordinary air, rises up to the annular gap 7.

The vapor-air mixture flow past the annular gap 7 is divided into two parts.

One, the first part of the specified flow through the profiled perforated bottom 13 is fed into the annular gap 11, between the pipe 1 and the inner shell 9, the other, the second part, into the annular gap 12 between the inner shell 9 and the outer shell 10, filled with coarse heat-exchanging material 16 .

The first part of the flow, passing through the annular gap 11, removes heat from the hot wall of the pipe body 1, heats itself further and enters the heated room. Part of the heat during movement of the specified part of the flow gives the inner shell 9.

The second part of the stream, passing through the annular gap 12, gives off heat to the coarse heat-exchanging material 16, heats it to the required temperature and also enters the heated room.

The regulation of the furnace traction is carried out by overlapping / opening the passage section of the chimney with a damper 15 mounted in the upper part 3 of the housing 1 for rotation.

The use of a steam-air mixture for heat transfer processes consisting of steam and humidified air having a heat capacity higher than ordinary dry air will significantly improve the heat transfer conditions between the working fluid - the obtained steam-air mixture - and the working bodies of the furnace - body 1, inner 9 and outer 10 shells at a constant fuel consumption, which ultimately will improve the efficiency of the furnace.

The tests carried out by the author and applicant of a full-sized furnace sample for the implementation of the proposed method confirmed the correctness of the design and technological solutions.

Using the proposed technical solution will create a method for the formation and heating of steam, the use of which will make it possible to increase the heat transfer of the combustion products of the fuel and significantly increase the operating time of the furnace at a constant fuel consumption with the possibility of producing superheated steam with controlled temperature and humidity.

Claims (8)

1. The method of supplying and heating steam, which consists in producing steam by heating the vaporizing liquid, followed by overheating of the obtained steam when it comes in contact with a heated heat-exchange coarse material, characterized in that the vaporizing liquid, mainly water, is poured into the container, which is formed by installation, mainly axisymmetrically, on the chimney of the shell of the shell with the bottom, while heat-exchange material, mainly stones, is placed in the said container, passed through the specified hot flue gases, preferably combustion products of the furnace, and thus heat the vaporizing liquid with the heat exchange material to the temperature of steam formation, while the steam obtained by heating the vaporizing liquid and moistened with air, forming the vapor-air mixture, is sent mainly along the pipe into the annular gap which is formed between the container lid and the chimney, and then into the annular cavities, internal and external, which are formed by installing a casing in the upper part of the pipe, yaschego of two shells - an inner and outer two shaped and perforated bottoms, installed at the ends of said shells, the cavity in the outer casing of said heat exchange material is placed. 2. The method of supplying and heating steam according to claim 1, characterized in that the upper profiled bottom of the casing is configured to change its flow area. 3. The method of supplying and heating steam according to claim 1, characterized in that the inner diameter d _{nn of the} inner shell of the casing is performed in the ratio d _nn ≈ (1.1 ... 1.5) D _tr , and the inner diameter d _{n of the} outer shell of the casing in the ratio d _n ≈ (1.1 ... 2) d _int , while the thickness s of the pipe walls, the inner and outer shells of the body is chosen in the ratio s≈ (0.04 ... 0.12) D _tr , where d _int is the inner diameter the inner shell of the casing, d _n - the inner diameter of the outer shell of the housing, D _Tr - the inner diameter of the pipe. 4. A method of supplying steam and heating according to claim 1, characterized in that the inner diameter of the container to operate in the evaporative liquid ratio _Em d ≈ (1,8 ... 3,0) D _TP, preferably D 2 _tr, where d _em - internal the diameter of the container for the vaporizing liquid, D _Tr - the inner diameter of the pipe. 5. The method of supplying and heating steam according to claim 1, characterized in that the lower bottom of the casing is installed from the lid of the container with vaporizing liquid, preferably an annular gap between the lid and the pipe at a distance of h≈ (0.01 ... 0.5) D _tr , where h is the distance from the lid of the container to the lower bottom of the casing, D _tr - the inner diameter of the pipe. 6. The method of supplying and heating steam according to claim 1, characterized in that a damper is installed in the upper output part of the pipe with the possibility of changing the pipe bore. 7. The method of supplying and heating steam according to claim 1, characterized in that the outer diameter of the annular gap between the cover of the vaporizing container and the pipe is not more than 1.5 D _tr , where D _tr is the inner diameter of the pipe. 8. The method of supplying and heating steam according to claim 1, characterized in that the length of the casing is performed in the following ranges: L≈ (1 ... 12) D _tr , where L is the length of the casing, D _tr is the inner diameter of the pipe.

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