KR101539936B1 - Exhaust heat recovery steam boiler using the two boilers - Google Patents

Abstract

The present invention relates to a waste heat recovery steam boiler using two boilers. The waste heat recovery steam boiler of the present invention comprises: a water storage tank (10); a first boiler and a second boiler (20, 30) respectively with a first water supply pipe and a second water supply pipe (21, 31) to supply water stored in the water storage tank (10); a first exhaust pipe and a second exhaust pipe (22, 32) connected for a combustion gas inside to be discharged to the outside; and a first steam supply line and a second steam supply line (23, 33) connected for the internal steam to be supplied into a flow path; a first waste heat recovery unit and a second waste heat recovery unit (40, 50) installed in an outer circumferential surface of each of the first exhaust pipe and the second exhaust pipe (22, 32) to be positioned at a certain interval; a raw water line (60) to supply water outside the flow path into the first waste heat recovery unit (40); a circulating line (70) to supply the water stored in the water storage tank (10) into the second waste heat recovery unit (50); a recovery line (80) to recover the water on which heat exchange is conducted in the second waste heat recovery unit (50) to the water storage tank (10); a circulating pump (90) placed in the circulating line (70) to selectively supply the water in the water storage tank (10) to the second waste heat recovery unit (50); and a return line (RW). The waste heat recovery steam boiler of the present invention recovers heat of the combustion gas using two boilers, supplies the preheated water to the boiler, and heats the water. Therefore, when the waste heat recovery steam boiler of the present invention is continuously operated, the temperature of the preheated water gradually increases, and the heat required to make water into steam is reduced. As a result, the thermal energy consumed to operate a boiler is reduced.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an exhaust heat recovery steam boiler using two boilers,

The present invention relates to a waste heat recovery steam boiler using two boilers, and more particularly, to a waste heat recovery steam boiler using two boilers, which is used to make and supply steam used to heat or sterilize a product during the manufacture of confectionery Steam steam boiler.

Generally, steam is produced by burning by using waste solidification fuel (RDF), waste plastic fuel (RPF), fossil fuel, biomass (hereinafter referred to as "fuel"), BACKGROUND ART In a boiler system, a waste heat recovery device of various shapes for recovering hot combustion gas, incineration heat and combustion waste heat generated when a fuel is burned to save fuel consumption is installed and used.

In this waste heat recovery apparatus, installed boilers are installed with different capacity of waste heat recovery apparatuses in large scale depending on the operating / site conditions. For this purpose, a spiral or zigzag shaped flow path is formed longer so that hot combustion gas, The time for heat exchange with the waste heat is increased, and thereby efforts are made to recover more waste heat.

However, it is a fact that the conventional waste heat recovery apparatus has a few inefficiency. The reason is that the waste heat recovery in the high temperature region is recovered by the small heat transfer area, but in the low temperature region, There is a limitation in sufficiently utilizing the heat of the combustion gas generated in the incineration and combustion facilities in the area.

To solve this problem, a waste heat recovery boiler having various shapes of waste heat recovery channels has been proposed, and through this, it has been tried to absorb the remaining heat in the high temperature region and the remaining heat in the low temperature region. However, merely how to install the spiral or zigzag There is a problem in that the efficiency of recovering the waste heat is low due to the conventional structural problem that the heat medium indirectly performs heat exchange and the effect of using the waste heat recovery apparatus is not high.

Thus, industrial boilers with high boiler operating rates, such as industrial boilers that produce steam for heating or sterilization purposes in the manufacture of confectionery, burn large quantities of fuel to produce steam continuously A large amount of heat energy is emitted by combustion gas and the like, and development of a waste heat recovery device capable of effectively recovering such waste heat is required.

KR 20-0397822 Y1 KR 20-0296522 Y1 KR 10-1030918 B1

Accordingly, the present invention has been made to solve the problems of the conventional waste heat recovery type boiler as described above, and it is an object of the present invention to reduce the amount of heat consumed to heat a steam using a boiler, And to provide a waste heat recovery steam boiler using two boilers which can save energy and cost required for the heat recovery.

An object of the present invention is to provide a steam boiler comprising: a water storage tank in which water is stored; A first and a second water supply pipes to which water stored in the water storage tank is supplied, first and second exhaust pipes communicating with each other to discharge combustion gas therein, and first and second exhaust pipes communicating with each other to supply steam therein, 2 steam supply lines, respectively; A first and a second waste heat recovery unit installed to surround the first and second exhaust pipes at predetermined intervals; A raw water line for supplying water outside the flow path to the inside of the first waste heat recovering unit; A circulation line for supplying water stored in the water storage tank to the inside of the second waste heat recovery unit; A recovery line in which the heat-exchanged water in the second waste heat recovery unit is recovered to the water storage tank; A circulation pump provided in the circulation line for selectively supplying water in the water storage tank to the second waste heat recovery unit; And a return line in which the steam supplied from the first and second steam supply lines is used and the remaining steam or water is stored in the water storage tank.

In this case, the first and second boilers may be provided with pressure sensors for sensing the internal pressure, respectively, and the supply flow rate may be adjusted according to the steam pressure generated in the first and second boilers.

The first and second waste heat recovery units may include a main body having a cylindrical shape and a receiving space formed therein; Wherein the first and second exhaust pipes are installed through the main body so that the water supplied to the accommodation space flows through the first and second exhaust pipes while directly contacting the outer peripheral surfaces of the first and second exhaust pipes, Heat exchange can be performed.

In addition, the first and second exhaust pipes may include a plurality of microfluidic channels, and the plurality of microfluidic channels may be installed to penetrate the mainframe.

In the meantime, a plurality of diaphragms may be installed in the first and second exhaust pipes so as to prevent the flow of the combustion gas for a relatively long period of time.

The plurality of diaphragms may be radially formed with a plurality of through holes, and when the plurality of diaphragms are provided in a plurality of layers, the through holes adjacent to the upper and lower sides may be positioned to be offset from each other.

Each of the first and second water supply pipes is provided with a flow rate sensor and the raw water line is provided with an automatic valve so that the automatic valve is automatically opened and closed according to the flow rate supplied to the first and second water supply pipes And the raw water is controlled to be supplied to the water storage tank through the raw water line.

Alternatively, the water storage tank may be provided with a level meter for sensing the amount of stored water, and an automatic valve may be provided on the raw water line to sense the height of water stored in the water storage tank, And the raw water is controlled to be supplied through the raw water line.

On the other hand, an auxiliary heat exchange unit is installed on the upstream side of either one or both of the first and second waste heat recovery units so as to surround the outer circumferential surfaces of the first and second exhaust pipes, . ≪ / RTI >

In the industrial boiler such as a boiler for supplying steam for sterilization or heating steam in the production of confection by using the present invention, the combustion gas burned in the inside of the two boilers is exhausted through the first and second exhaust pipes, Heat is recovered by the installed first and second waste heat recovery units, and the waste heat is recovered and the preheated water is supplied to each of the first and second boilers while being stored in the water storage tank, so that the steam is produced in each boiler The amount of heat energy consumed is reduced, and the cost of fuel for operating the boiler is significantly reduced.

Further, the present invention can control the flow path so as to circulate the waste heat recovery unit and the water storage tank as necessary, and in this case, the temperature of the water stored in the water storage tank can be further preheated, The amount of heat energy required to be supplied into the boiler and heated by the steam can be reduced.

In the meantime, according to the present invention, diaphragms having a plurality of through holes radially formed in the first and second exhaust pipes are provided in a multi-layer structure, and the through holes of the respective diaphragms are arranged such that the positions of the through holes adjacent to each other in the upper and lower sides are shifted from each other The time during which the combustion gas is exhausted through the first and second exhaust pipes can be relatively slowed, and thus the waste heat recovering performance can be further improved.

1 is a view showing an example of a waste heat recovery steam boiler using two boilers according to the present invention,
2 is a perspective view showing an example of a waste heat recovery type steam boiler using two boilers according to the present invention,
3 is a perspective view showing an example of the first and second waste heat recovering units of the present invention,
4 and 5 are a cross-sectional view and a flat cross-sectional view showing an example of a microcompartment of the present invention,
6 is a plan sectional view showing an example of a corrugated pipe according to the present invention,
7 is a perspective view showing an example in which diaphragms are installed on the first and second exhaust pipes of the present invention,
8 is a sectional view showing an example of the auxiliary heat exchanging unit of the present invention.

Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

The present invention relates to a waste heat recovery steam boiler using two boilers which can reduce the heat energy required to generate steam by recovering the waste heat of the combustion gas by using two industrial boilers, will be.

1, the present invention includes a water storage tank 10, first and second boilers 20 and 30, first and second waste heat recovery units 40 and 50, a raw water line 60, The circulation line 70, the recovery line 80, the circulation pump 90, and the return line RW, and the above-described configurations will be described in detail below.

The water storage tank 10 is formed in a cylindrical or rectangular box shape as shown in FIGS. 1 and 2, and a proper water storage space for storing water therein is provided therein.

The water storage tank 10 is connected to the first and second water supply pipes 21 and 31 to be described later, the raw water line 60 and the circulation line 70, the recovery line 80 and the return line RW, Water is supplied or stored into the water storage tank 10 through the circulation line 70 or the first and second water supply pipes 21 and 31 to the second waste heat recovery unit 50 or the first and second boilers (20, 30).

The water storage tank 10 is provided with a level meter LM for sensing the amount of stored water and an automatic valve SV is provided in the raw water line 60 to be described later. The automatic valve SV is automatically opened and closed by detecting the height of the water storage tank 10 so that an appropriate amount of raw water is supplied to the raw water line 60 so that the water in the water storage tank 10 is always kept constant.

Alternatively, the first and second water supply pipes 21 and 31 are provided with flow rate sensors FS1 and FS2, respectively, and the raw water line 60 is provided with an automatic valve SV, The automatic valve SV can be controlled to be automatically opened and closed according to the flow rate supplied to the water supply lines 21 and 31 so that water is supplied through the raw water line 60.

The first and second boilers 20 and 30 which supply the water stored in the water storage tank 10 and generate steam by heating using fuel (gas) (2) water supply pipes (21, 31), first and second exhaust pipes (22, 32) communicating with the inner combustion gas to be discharged to the outside, first and second steam And supply lines 23 and 33, respectively.

1 and 2, burners 24 and 34 are installed in each of the first and second boilers 20 and 30 so that fuel (gas) Is supplied from the gas storage tank 10 through the first and second water supply pipes 21 and 31 to the first and second boiler The water supplied to the inside of the first and second water supply passages 20 and 30 is heated.

At this time, a water tank (not shown) for storing a predetermined amount of water is provided in the first and second boilers 20 and 30, and the bottom of the water tank is heated by the burners 24 and 34 to generate steam .

The steam generated by heating the water supplied into the first and second boilers 20 and 30 is supplied to the manufacturing process or the sterilization process through the first and second steam supply lines 23 and 33, 24 and 34 are exhausted to the outside through the first and second exhaust pipes 22 and 32.

At this time, the first and second waste heat recovery units 40 and 50, which will be described later, are installed on the outer circumferential surfaces of the first and second exhaust pipes 22 and 32, thereby recovering the waste heat of the exhaust gas.

Pressure sensors PS1 and PS2 for detecting internal pressures are installed in the first and second boilers 20 and 30 so that water is supplied to the first and second boilers 20 and 30 in accordance with the steam pressure generated in the first and second boilers 20 and 30. [ For example, if the internal pressure of the first and second boilers 20 and 30 is lower than the set reference pressure, it means that steam can be further generated. Higher steam means that the produced steam stays inside, which reduces the amount of water supplied and reduces the amount of steam generated.

In addition to this operation, it is preferable that the present invention simultaneously controls the operation of the burners 24 and 34 installed in the first and second boilers 20 and 30, respectively.

The first and second waste heat recovery units 40 and 50 installed in the first and second exhaust pipes 22 and 32 of the first and second boilers 20 and 30 are formed into a cylindrical shape as shown in FIG. A main body 41 and 51 in which a receiving space S is formed and a heat insulating member 42 and 52 which are installed to surround the outer circumferential surface of the main body 41 and 51.

The first and second exhaust pipes 22 and 32 of the first and second boilers 20 and 30 are installed to pass through the main body 41 and 51 and are supplied to the receiving space S inside the main bodies 41 and 51 So that the water flows while directly contacting the outer peripheral surfaces of the first and second exhaust pipes (22, 32).

The main body 41 of the first waste heat recovering unit 40 is connected to a raw water line 60 at the upper part and the lower part thereof to supply raw water to the inside of the first waste heat recovering unit 40 to be heat exchanged and then water preheated by the water storage tank 10 is supplied Respectively.

The main body 51 of the second waste heat recovering unit 50 is connected to the upper and lower collecting lines 80 and the circulation line 70 so that the water stored in the water storage tank 10 Is supplied to the inside of the second waste heat recovering unit (50) through the circulation line (70), and then supplied to the water storage tank (10) through the recovery line (80) to store the preheated water.

Therefore, when raw water is supplied into the flow path through the first waste heat recovering unit 40, the liquefied water is primarily preheated so that lukewarm water is stored in the water storage tank 10, So that the temperature of the water rises again.

At least one circulation pump 90 is provided on the flow path for circulating the water in the flow path and the first boiler 20 or the second boiler 30 is controlled by controlling the operation of the circulation pump 90. [ Or supplies the water stored in the water storage tank 10 to the second waste heat recovering unit 50.

On the other hand, the present invention can further increase the temperature of the water stored in the water storage tank 10 by circulating the water to the second waste heat recovery unit 50 continuously or periodically, if necessary, Since the temperature of the water supplied to the boilers 20 and 30 is supplied as much as it is, the heat energy required to make the water vapor by using the burners 24 and 34 is reduced, and the steam can be produced more rapidly .

As shown in FIGS. 4 and 5, in order to improve the waste heat recovering performance of the first and second waste heat recovering units 40 and 50, the first and second boilers 20 and 30, A plurality of fine distributors (22A, 32A) are formed in the exhaust pipes (22, 32) so as to penetrate the main bodies (41, 51) of the first and second waste heat recovering units The branch pipes 22A and 32A may be installed inside.

When this process is carried out, the combustion gas is exhausted to the relatively small diameter fine bifurcations 22A and 32A, and the effect that the outer peripheral face of each of the fine bifurcations 22A and 32A is in direct contact with water and the heat transfer area is widened And as a result, it is possible to ensure proper waste heat recovering performance.

Instead of forming the first and second exhaust pipes 22 and 32 as the fine branch pipes 22A and 32A, as shown in FIG. 6, the first and second exhaust pipes 22 and 32, (22B). In this case, the effect of widening the heat transfer area relative to the cylindrical first and second exhaust pipes (22, 32) can be expected, and the waste heat recovering performance is also improved.

On the other hand, the raw water line 60 for supplying water outside the flow path to the inside of the first waste heat recovering unit 40 is connected to a pipe such as a water supply, and the automatic valve SV is installed as described above, The flow rate supplied to the recovery unit 40 is automatically adjusted.

The circulation line 70 is a structure for supplying the water stored in the water storage tank 10 to the inside of the second waste heat recovery unit 50 and the recovery line 80 is a part for performing heat exchange in the second waste heat recovery unit 50 So that the water is returned to the water storage tank 10 again.

In addition, the return line RW is a structure in which the steam supplied to the heating process or the sterilization process is left unused or the temperature of the steam is lowered so that the phase-changed water is recovered and stored in the water storage tank 10 again.

On the other hand, in the present invention, an appropriate amount of waste heat can be recovered by the first and second waste heat recovery units (40, 50), but a larger amount of heat exchange may be required depending on the capacity of the first and second boilers In this case, when the diameters of the first and second waste heat recovery units 40 and 50 are increased, the volume of the interior space increases. Therefore, the area where the heat exchange is performed by directly contacting the first and second exhaust pipes 22 and 32 Therefore, it is necessary to form the exhaust pipes 22 and 32 along the length of the first and second exhaust pipes 22 and 32, which may limit the installation space.

Accordingly, as shown in FIG. 7, when the combustion gas exhausted through the first and second exhaust pipes 22 and 32 passes through the section where the first and second waste heat recovery units 40 and 50 are installed , The waste heat recovering performance can be improved even if the diameter of the first and second waste heat recovering units (40, 50) is maintained.

More specifically, a plurality of disk-shaped partition plates P are installed in the first and second exhaust pipes 22 and 32. At this time, the plurality of partition plates P are radially provided with a plurality of through- Holes H are formed so that when the plurality of partition plates P are provided in a multi-layer structure, the through holes H are vertically adjacent to each other.

According to this structure, when the combustion gas passes through the section where the first and second waste heat recovering units 40 and 50 are installed, the combustion gas flows at a low speed while flowing in the oblique direction along the through holes H staggered from each other.

At this time, the combustion gas heats the diaphragm P while passing through the plurality of diaphragms P, and the heat energy of the diaphragm P thus heated is transmitted to the first and second exhaust pipes 22 and 32, The waste heat recovery performance of the first and second waste heat recovery units 40 and 50, which are in direct contact with the outer circumferential surfaces of the first and second exhaust pipes 22 and 32 and are heat-exchanged, can be further improved.

On the other hand, as shown in Fig. 8, the first and second exhaust pipes 22 and 32 (see Fig. 8) are disposed on the upstream side of one or both of the first waste heat recovering unit 40 and the second waste heat recovering unit 50 And an auxiliary heat exchanging unit 100 installed to interpose the plurality of heat transfer plates 101 for storing water therein.

Since the auxiliary heat exchanging unit 100 has a relatively large diameter, a large amount of raw water flows into the auxiliary heat exchanging unit 100 from the first and second exhaust pipes 22 and 32 by the heat transfer plate 101 The preheated water is passed through the first and second exhaust pipes 22 and 22 while passing through the space S having a relatively small diameter of the first and second waste heat recovering units 40 and 50 installed at the lower part thereof. , 32, so that the waste heat recovering performance can be improved and at the same time, a large amount of raw water can be preheated to a high temperature and supplied to the water storage tank (10) Sufficient heat recovery performance can be expected.

Industrial Applicability As described above, in an industrial boiler such as a boiler for supplying steam for baking or steam for sterilization, the combustion gas burned in the two boilers is exhausted through the first and second exhaust pipes, And the waste heat is recovered and the preheated water is supplied to the first and second boilers in a state where they are stored in the water storage tank, so that the steam is produced in each of the boilers The amount of heat energy consumed by the boiler is reduced, and the cost of the fuel for operating the boiler is greatly reduced.

10: water storage tank 20: first boiler
21: first water supply pipe 22: first exhaust pipe
22A: fine particle tube 23: first vapor supply line
24: burner 30: second boiler
31: second water supply pipe 32: second exhaust pipe
32A: fine distribution tube 33: second vapor supply line
34: burner 40: first waste heat recovery unit
41: main body 42:
50: second waste heat recovery unit 51:
52: insulation member 60: raw water line
70: circulation line 80: recovery line
90: circulation pump 100: auxiliary heat exchange unit
101: Thermal plate FS1, FS2: Flow sensor
H: Through hole LM: Level meter
P: diaphragm RW: return line
PS1, PS2: Pressure sensor S: Capacity
SV: Automatic valve

Claims (9)

A water storage tank (10) in which water is stored;
First and second water supply pipes 21 and 31 to which the water stored in the water storage tank 10 is supplied, first and second exhaust pipes 22 and 32 communicating with each other to discharge the combustion gas therein, A first and a second boiler (20, 30) in which first and second steam supply lines (23, 33) are provided so that steam of the steam generator is supplied to the inside of the flow passage;
A first and a second waste heat recovery units 40 and 50 installed to surround the first and second exhaust pipes 22 and 32 at predetermined intervals;
A raw water line (60) for supplying water outside the flow path to the inside of the first waste heat recovering unit (40);
A circulation line (70) for supplying the water stored in the water storage tank (10) to the inside of the second waste heat recovering unit (50);
A recovery line (80) for recovering heat-exchanged water from the second waste heat recovery unit (50) to the water storage tank (10);
A circulation pump (90) provided in the circulation line (70) for selectively supplying water in the water storage tank (10) to the second waste heat recovery unit (50);
And a return line (RW) in which the steam supplied from the first and second steam supply lines (23, 33) is used and the remaining steam or water is stored in the water storage tank (10) Waste Heat Recovery Steam Boiler.
The method according to claim 1,
In the first and second boilers 20 and 30,
Pressure sensors PS1 and PS2 for detecting the internal pressure of the boilers 20 and 30 are installed to adjust the supply flow rate according to the steam pressure generated in the first and second boilers 20 and 30. [ Waste Heat Recovery Steam Boiler.
The method according to claim 1 or 2,
The first and second waste heat recovering units (40, 50)
A main body 41, 51 formed in a cylindrical shape and having a receiving space S formed therein;
And heat insulating members (42, 52) installed to surround the outer peripheral surfaces of the main bodies (41, 51)
The first and second exhaust pipes 22 and 32 are installed through the main body 41 and 51 so that water supplied to the accommodation space S is directly supplied to the outer circumferential surfaces of the first and second exhaust pipes 22 and 32, And the heat exchange is carried out while contacting the steam boiler.
The method of claim 3,
The first and second exhaust pipes (22, 32)
Includes a plurality of fine branch pipes (22A, 32A)
The waste heat recovery steam boiler according to any one of claims 1 to 3, wherein the plurality of minute branch pipes (22A, 32A) are installed to pass through the main body (41, 51).
The method according to claim 1,
A plurality of diaphragms (P) are installed in the first and second exhaust pipes (22, 32) so as to prevent the flow of the combustion gas for a relatively long time. Steam boiler.
The method of claim 5,
A plurality of through holes (H) are radially formed in the plurality of partition plates (P)
Wherein when the plurality of partition plates (P) are installed in a multi-layer structure, the through holes (H) adjacent to the upper and lower sides are positioned so as to be offset from each other.
The method according to claim 1,
Each of the first and second water supply pipes 21 and 31 is provided with flow rate sensors FS1 and FS2,
The raw water line (60) is provided with an automatic valve (SV)
The automatic valve SV is controlled to be automatically opened and closed according to a flow rate supplied to the first and second water supply pipes 21 and 31 so as to be supplied through the raw water line 60. [ Waste Heat Recovery Steam Boiler.
The method according to claim 1,
The water storage tank 10 is provided with a level meter LM for sensing the amount of stored water,
The raw water line (60) is provided with an automatic valve (SV)
The automatic valve SV is controlled to be automatically opened and closed by controlling the height of the water stored in the water storage tank 10 so that raw water is supplied through the raw water line 60. [ Recuperative steam boiler.
The method according to claim 1,
The first and second exhaust heat collecting units 40 and 50 are installed upstream of one or both of the first and second exhaust heat collecting units 40 and 50 so as to surround the outer circumferential surfaces of the first and second exhaust pipes 22 and 32, And an auxiliary heat exchanging unit (100) installed at the other end of the auxiliary heat exchanging unit (100).

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