JP2000055572A - Vapor latent heat recovery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase vapor latent heat to be recovered in combined cycle or melting furnace and to utilize it effectively by throwing masses or fine particles of ice into exhaust gas and condensing vapor in the exhaust gas around the ice or the melted water utilizing the latent heat at the time of melting ice. SOLUTION: Refrigerant compressed adiabatically by a compressor 4 is cooled and liquefied by a condenser 3 and then expanded adiabatically by a pressure reducing mechanism 5 to produce cryogenic refrigerant. The cryogenic refrigerant is introduced to an evaporator 6 in order to cool it and then returned through a pipe 8 back to the compressor 4. When water is fed to the outer surface of the evaporator 6, the water is frozen and the ice thus produced is scraped and thrown into a hopper 11 and then fed to a duct 10 through a rotary valve 15. The ice 12 is heated with exhaust gas 300 to produce water 13 and the vapor in the exhaust gas 300 is condensed with the latent heat around the ice 12 or the water 13. The water 13 is stored in a water collector 106 comprising a pit 14 and then fed to a water tank 18 by driving a pump 17 and utilized effectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for recovering steam latent heat in an exhaust gas of a combined cycle and an exhaust gas of a molten steel furnace to effectively use the heat, and an apparatus for effectively using water generated at the time of recovering the steam latent heat. .

[0002]

2. Description of the Related Art As a conventional technique related to the present invention, as described in the literature (■ 97-25 Proceedings of the Japan Society of Mechanical Engineers Thermal Engineering Lecture P130-131 [1997-11, 5-7 Tsukuba]), The steam in the exhaust gas is condensed around the frosted water by spraying water such as seawater into the exhaust gas duct, and the condensed water of the steam is collected together with the frosted water, thereby effectively utilizing the recovered latent heat. Alternatively, the condensed water recovered is put into the system again for effective use.

[0003]

In the above prior art, water is injected into an exhaust gas duct, and sensible heat based on the specific heat of water is small. And the amount recovered was not sufficient.

[0004]

In order to solve the above-mentioned problems, the present invention introduces ice blocks or ice particles into exhaust gas. The vapor in the exhaust gas requires a large amount of heat due to the latent heat when the ice melts, and condenses around the ice or around the melted water. As a result, the recovery amount of the latent heat of steam is significantly increased and can be used effectively.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a configuration diagram of an embodiment of a steam latent heat recovery apparatus according to the present invention. There is a water recovery unit 106 including a hopper 11 for charging ice particles 12 into a duct 10 through which exhaust gas passes and a water reservoir 14 for storing water 13. Ice particles or ice blocks 12 are put into the hopper 11 by the ice maker 1. The ice maker 1 includes a compressor 4, a condenser 3, a pressure reducing mechanism (expansion valve) 5, an ice maker 2 equipped with an evaporator 6, and pipes 7, 8, 9 connecting them, and enclosed in the circuit thereof. It is composed of a refrigerant (such as Freon).

The refrigerant adiabatically compressed by the compressor 4 is cooled and liquefied in the condenser 3, and then adiabatically expanded in the pressure reducing mechanism 5 to a low temperature. This low-temperature refrigerant flows into the evaporator 6, cools the evaporator 6, returns to the compressor 4 via the pipe 8, and repeats the same cycle as before. When water flows down on the outer surface of the evaporator 6, the water freezes on the outer surface of the evaporator 6, and the ice generated by this is appropriately removed and put into the hopper 11. A rotary valve 15 is provided in the hopper 11, and the ice
2 is introduced into the duct 10 through which the exhaust gas 300 passes.

The ice 12 in the exhaust gas 300 receives the heat of the exhaust gas and substitutes for water. At this time, the vapor in the exhaust gas is condensed around the ice or the water generated by the melting due to the large latent heat of the melting of the ice. This water accumulates in a water recovery unit 106 including a water reservoir 14 provided in the duct 10. This water 13
Is sent to a water tank 18 by driving a pump 17 of a pipe 16 connected to the water reservoir 14. The water 13 is used as it is by returning to the system, or a heat medium is introduced into a heat exchanger 24 provided in the water tank 18 by using an inlet pipe 26, an outlet pipe 27, and a pump 25 to be taken out as heat. And use it effectively.

FIG. 2 illustrates the phase change of the ice 12 put into the duct 10. FIG. 2A shows the initial ice 12 charged into the exhaust gas 300. FIG. 2 (b) shows a state in which the outer peripheral surface of the ice 12 is melted by the heat of the exhaust gas and turned into water 13, and the vapor in the exhaust gas 300 condenses on this surface and the amount thereof increases. It is. FIG. 2 (c)
Shows the state when the ice 12 is completely melted and the whole is turned into water. When all of the ice 12 is melted, the volume increases as water due to condensation of the steam. Therefore, a large amount of water accumulates in the puddle 14 of the water recovery unit 106.

FIG. 3 is a block diagram of another embodiment of the present invention. This is an example where the configuration of the ice maker 1 is different from that of FIG. The ice making unit 2 of the ice making machine 1 has a cylindrical or box-like shape, and an evaporator 6 is provided therearound. The ice making unit 2 is cooled while passing the cooled refrigerant into the evaporator 6,
Further, the internal space is cooled. An injection valve 22 is provided in the internal space of the ice making unit 2, and water is sprayed from the injection valve 22.

In this method, an air compressor 20 is used, a pipe 21 connected thereto is used, and a valve 23 attached thereto is opened to send high-pressure air to an injection valve 22. A water pipe 28 provided with a valve 29 is mounted in the middle of the pipe 21, and water is injected into the pipe 21 by opening the valve 29 to supply water and air into the injection valve 22 at the same time.

[0011] Since water is jetted at the same time as air is jetted from the injection valve 22, the water is frosted, and this water comes into contact with the cooled air in the internal space of the ice making unit 2 and changes into ice particles 12. The ice particles 12 are put into the hopper 11 as they are. In this embodiment, the water pipe 2 with the valve 29
8 may be directly attached to the injection valve 22. In this case, water and air are simultaneously ejected from the injection valve 22.

In this embodiment, the heat exchanger 24 is provided at the pipe 16 after the pump 17 connected to the water sump 14 has exited, but the inlet pipe 26, the outlet pipe 27, the pump 2
5, a heat medium is introduced into the heat exchanger 24,
Heat is exchanged with the hot water supplied to the inside 6 to obtain heat, and this heat can be supplied to the outside to be effectively used.

FIG. 4 is a block diagram of another embodiment of the present invention. This is an example in which the ice maker 1 is constituted by a chemical thermal storage type ice maker. The chemical regenerative ice maker 1 comprises a heat storage container 30 containing a chemical heat storage material 31, a condenser 32, an evaporator 34 containing a refrigerant 33, a pipe 38 with a valve 39 connecting the heat storage container 30 and the condenser 32, and a condenser 38. It comprises a pipe 35 connecting the evaporator 32 and the evaporator 34, and a pipe 36 having a valve 37 connecting the evaporator 34 and the pipe 38 (or the heat storage container 30).

The method of operation is as follows. After heat is applied to the chemical heat storage material (silica gel, zeolite, quicklime, etc.) 31 in the heat storage container 30 to dry and regenerate it, the refrigerant (ethanol, ethanol, etc.) in the evaporator 34 is cooled. While evaporating 33, such as methanol, calcium chloride aqueous solution, and ethylene glycol aqueous solution), the vapor is introduced into the heat storage container 30 via the pipe 36 and is adsorbed on the chemical heat storage material 31 or chemically reacted therewith, thereby evaporating. Refrigerant 3 in vessel 34
3 is cooled to below the freezing temperature of water. Thereafter, the valve 37 attached to the pipe 36 is closed, and the valve 39 attached to the pipe 38 is opened to heat the chemical heat storage material 31.

As the method, there is a method in which the heat is input to the heater 40 provided in the heat storage container 30 and a method in which a high-temperature heat medium is introduced into the heat exchanger 58 provided in the heat storage container 30 for heating. There is. In the latter case, a heat exchanger 59 is provided in the duct 10 through which the exhaust gas passes, and the internal heat medium (such as water) is circulated using the pump 60 and the pipes 61 and 62 to store the heat held by the exhaust gas in the heat storage container 30. Chemical heat storage material 3
It can also be given to 1 and heated.

As a method of cooling the ice making section 2, a heat exchanger 54 provided in the evaporator 34 and a heat exchanger 55 provided in the ice making section 2 are thermally connected by pipes 57 and 56 and a pump 53, The heat generated inside the evaporator 34 is transported to the ice making unit 2 by circulating a heat medium therein (such as an antifreeze using an ethylene glycol aqueous solution). This makes the ice making unit 2
Freezes the water supplied to the tank. Ice 12 generated in ice making unit 2
Is fed into the stripper hopper 11 as appropriate. Thermal storage container 3
0 and the water 1 stored in the water tank 18 for cooling the condenser 32.
3 is used.

The water 13 stored in the water tank 18 is supplied to a pump 49.
Through the pipe 50, the valve 48, and the pipe 42 to the heat exchanger 44, thereby cooling the condenser 32. Subsequently, the heat is sent to the heat exchanger 41 to remove heat generated from the chemical heat storage material 31 in the heat storage container 30. Thereafter, the water 13 that has passed through the heat exchanger 41 is returned to the water tank 18 via the pipe 43.

The water 13 in the water tank 18 is pumped by a pump 49.
By opening the valve 47 provided on the pipe 46 branched and connected to the pipe 50, the water 13 is supplied to the water spray mechanism 67 provided on the cooling tower 63, whereby the water 13 is supplied to the packing 6.
Run down to 8 parts. The air is sent around the packing 68 by the operation of the cooling fan 66, whereby the water 13 flowing down to the packing 68 is cooled, and the water 13 flowing down is stored in the tank 64 below the cooling tower 63. By opening the valve 52 of the pipe 51 attached to the tank 64, the water 13 in the tank 64 is returned to the water tank 18 in the lower part. In this way, the cooling water supplied to the heat exchanger 44 provided in the condenser 32 and the heat exchanger 41 provided in the heat storage container 30 is always cooled.

FIG. 5 is a block diagram of another embodiment of the present invention. This is such that the water 13 in the water tank 18 is supplied to the injection mechanism 77 by driving the pump 71 through the pipes 70, 73, 76 attached thereto. The water injected from the injection mechanism 77 is supplied into the duct 10 through which the exhaust gas passes. This allows the hopper 11
Exhaust gas 30 before the ice particles introduced into the duct 10
Thus, the amount of ice particles 12 consumed can be reduced. For this reason, the capacity of the ice maker 1 can be reduced to save energy. The amount of water jetted from the jetting mechanism 77 is adjusted by adjusting the opening of the valve 72 attached to the pipe 73.

In this embodiment, a pipe 75 is provided with a valve 74 branching off from the pipe 73. This pipe supplies a part of the water supplied to the pipe 73 to the hopper 11 via the pipe 75. Ice particles 1 in the hopper 11
2 facilitates introduction into the duct 10 from the hopper 11.

FIG. 6 is a block diagram of a modified embodiment of FIG.
This is achieved by providing a heat exchanger 78 in the duct 10 instead of the injection mechanism 77 of FIG. 5, cooling the exhaust gas 300 through water supplied to the pipe 73 in the heat exchanger 78, and then cooling the water tank through the pipe 79. 18 is returned.
The water returned from the pipe 79 may be directly injected into the water spray mechanism 67 to spray water on the packing 68 to cool it. Heat exchanger 7
Vapor may be condensed from the exhaust gas 300 in the duct 10 on the surface of the duct 8, but this condensed water drops as droplets from the heat exchanger 78 and passes through the lower part of the duct 10 into the water sump 14. Collected.

FIG. 7 is a block diagram of a modified embodiment of FIG.
FIG. 8 is a sectional view taken along the line AA '. This is one in which a plate (iron or stainless steel) 80 is provided in the exhaust gas 300 in the duct 10. This is to prevent the ice particles 12 or water droplets generated by melting of the ice particles 12 from scattering to the downstream side of the duct 100 together with the exhaust gas 300. That is, the plate 80
Since the ice particles 12 or water droplets come into contact with and collide with the water, they will not fly farther downstream. Liquid film 13 sticking to plate 80
-A flows down and collects in the puddle 14. A mesh 81 is provided on the upper part of the puddle 14 to prevent the water 13 in the puddle 14 from being disturbed by the flow of the exhaust gas 300 and scattered again in the wake of the duct 10. is there.

FIG. 9 is a block diagram of a modified embodiment of FIG.
In this case, the plate 80 is made of a corrugated plate, and the ice particles 12 or droplets are more likely to collide with the plate 80 as compared with a flat plate. Instead of the plate 80, a heat-resistant stone or ceramic plate may be packed. In this embodiment, the duct 10 and the pool 14 are connected by a plurality of pipes 81-a. By doing so, a better effect than the mesh 81 is produced.

FIG. 10 is a block diagram showing an example of a method of using the latent heat recovery apparatus of the present invention. This is a combination of a combined cycle system and a steam latent heat recovery device. The combined cycle system is an air compressor 10
0, combustor 107, gas turbine 101, steam turbine 102, generator 103, waste heat boiler 105, condenser 1
A system 04 is combined as shown. The exhaust heat generated in the gas turbine 101 enters the exhaust heat boiler 105 through the duct 123, and then the exhaust duct 10
Finally, it is released to the atmosphere from the chimney.

On the other hand, the steam generated from the exhaust heat boiler 105 enters the steam turbine 102 through a pipe 125, and after expanding, enters the condenser 104 through a pipe 126. Part of the water in the water recovery unit 106 of the steam latent heat recovery device of the present invention provided in the exhaust duct 10 is used for heating the supply water of the exhaust heat boiler 105 via the pipe 117. To this end, water is supplied to the water supply section of the exhaust heat boiler 105 by driving the water supply pump 108 via the pipe 116 branched and connected to the pipe 117. The adjustment of the amount is adjusted by adjusting the opening of the valve 110 attached to the pipe 116.

The remaining water is driven by a pump 109 through a pipe 118 having a valve 111, through a pipe 119 to the intake duct 115 of the air compressor 100, to the combustor 107, and to gas. It is supplied to the turbine 101. The supply of water to these components contributes to an increase in the output of the generator 103.

The supply amount to the air compressor 100 is
The amount of supply to the combustor 107 is controlled by a valve 113 of a pipe 121 that is branched and connected to the pipe 119.
The supply amount to the gas turbine 101 is adjusted by a valve 114 of a pipe 122 branched and connected to the pipe 119. When supplying the recirculated water to the air compressor 100, it is preferable to use a cooling tower or the like, or use LNG cold heat or the like to cool the water to lower temperature.

In this embodiment, the fuel supply mechanism 127 of the combustor 107 is provided with the LNG from the LNG tank 200.
The LNG is transported through the pipe 202 by driving the pump 201 and the ice making machine 1 is used.
To vaporize LNG. Ice is generated in the evaporator 6 of the ice making machine 1 by the cold heat of the LNG, while LNG is vaporized and supplied to the fuel supply mechanism 127, so that both advantages are obtained.

[0029]

As described above, according to the present invention,
(1) A large amount of steam present in the exhaust gas is recovered as water due to the latent heat when the ice liquefies. (2) Water can be recycled as a system in addition to the effective use of the heat possessed by this water. , (3) In addition, the effective use of LNG refrigeration has become possible, and it has been practically convenient.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of one embodiment of a steam latent heat recovery device of the present invention.

FIG. 2 is a diagram illustrating a state of a phase change of ice 125 put into a duct 10.

FIG. 3 is a configuration diagram of another embodiment of the steam latent heat recovery device of the present invention.

FIG. 4 is a configuration diagram of another embodiment of the steam latent heat recovery device of the present invention.

FIG. 5 is a configuration diagram of another embodiment of the steam latent heat recovery device of the present invention.

FIG. 6 is a configuration diagram of a modified example of FIG. 5;

FIG. 7 is a configuration diagram of a modified example of FIG. 1;

FIG. 8 is a sectional view taken along line AA of FIG. 7;

FIG. 9 is a view showing a modified example of FIG. 8;

FIG. 10 is a configuration diagram showing an example of how to use the latent heat recovery apparatus of the present invention.

[Explanation of symbols]

1 ... ice machine, 2 ... ice making section, 3, 32 ... condenser, 4,10
0: compressor, 5: decompression mechanism, 6, 34: evaporator, 7,
8, 9 ... piping, 10 ... duct, 11 ... hopper, 12 ...
Ice particles, 13: water, 14: puddle, 15: rotary valve, 16, 21, 35, 36, 38, 42, 43, 4
5,46,50,51,56,57,61,62,7
0, 73, 75, 76, 79, 81-a, 116, 11
7, 118, 119, 120, 121, 122, 12
5, 126, 202 ... pipe, 17, 25, 49, 5
3, 60, 71, 108, 109: pump, 18: water tank, 20: air compressor, 22: injection valve, 23, 29, 3
7, 39, 40, 47, 48, 52, 69, 72, 7
4, 110, 111, 112, 113, 114 ... valves, 24, 54, 55, 58, 59, 78 ... heat exchangers
26 inlet pipe, 27 outlet pipe, 28 water pipe, 30 heat storage vessel, 31 chemical heat storage material, 33 refrigerant
41, 44: heater, 63: cooling tower, 64: tank, 65
... envelope, 66 ... fan, 67 ... watering mechanism, 68 ... packing, 77 ... injection mechanism, 80 ... plate, 81 ... mesh,
101: gas turbine, 102: steam turbine, 103
... generator, 104 ... condenser, 105 ... waste heat boiler, 1
06 ... water recovery unit, 107 ... combustor, 115 ... intake duct, 123 ... duct, 127 ... fuel supply mechanism, 200 ...
LNG tank, 201 ... LNG pump, 300 ... Exhaust gas.

Claims (1)

[Claims] 1. A method for recovering steam latent heat by charging ice into an exhaust gas, condensing steam in the exhaust gas using latent heat when the ice melts, collecting the water, and effectively utilizing the water and the latent heat of the steam. apparatus.