JPS59193205A - Waste heat recovery equipment of cooling water of shaft furnace body - Google Patents

Abstract

PURPOSE:To recover the heat possessed by relatively low temp. waste cooling water in good efficiency, by providing a heat pump and low b.p. heating medium generation equipment in the recirculation route of cooling water and waste water in the cooling system of a shaft furnace body. CONSTITUTION:The waste cooling water having a relatively low temp. of 60 deg.C or less issued from cooling disks divided into plural sets for cooling a shaft furnace body 1 is gathered to a main drain pipe 4 and raised in temp. by an absorbing type heat pump 18 while a part of the waste water is taken out as high temp. water at 70 deg.C or more. The remainder of the waste water is cooled and taken out as low temp. cooling water 24. The high temp. cooling water having a temp. of 70 deg.C or more is introduced into the low b.p. heating medium steam generator of low b.p. heating medium turbine generation equipment 23 to generate low b.p. steam and a turbine is operated to generate electricity. The low temp. cooling water 24 from one outlet of the heat pump 18 and the cooling water 25 cooled by the low b.p. heating medium steam generator are again recirculated to the cooling disks 2 of the shaft furnace to be used as cooling water.

Description

DETAILED DESCRIPTION OF THE INVENTION In recent years, there has been a demand for energy saving, and the use of medium and low temperature waste heat from various types of equipment has been implemented.

In the blast furnace body cooling system, a large amount of cooling water is used to prevent cooling bodies such as stave coolers and cooling plates from being damaged at high temperatures inside the blast furnace. The temperature of the cooling waste water is as low as about 50℃ or less because the cooling system is divided into several sections to avoid chain reaction failure of cooling bodies in the same cooling system when the cooling body is damaged. .

For this reason, even if thermal energy is recovered using a low boiling point heat medium turbine power generation system or the like, the capacity of the heat exchanger is large and the generated steam pressure of the low boiling point heat medium is low, resulting in a small amount of power generation.

Therefore, the current situation is that it is not economically viable.

On the other hand, in order to reduce the temperature of the waste water to the desired temperature of the water supply, since the cooling water cannot be recirculated, it is cooled using a seawater cooler or the like. This cooling equipment requires enormous equipment and operating costs.

The present invention is a waste heat recovery equipment for blast furnace body cooling water related to a method for recovering waste water thermal energy to solve such disadvantages, and its gist is the circulation of cooling water and waste water in a blast furnace body cooling system. A heat pump and low boiling point heat medium power generation equipment are installed in the route.

That is, the present invention utilizes an absorption-type heat pump, a compression-type heat pump, or the like in order to raise the cooling water drainage temperature to about 70° C. or higher, which is necessary for economical low-boiling point heat medium turbine power generation.

Thereafter, heat is exchanged with a low boiling point heat medium to obtain pressure steam to drive a turbine, generate electricity 1, and recover waste water thermal energy.

The explanation will be given below with reference to the drawings.

Figure 1 shows a system diagram of a cooling plate type furnace body cooling system.

A large number of cooling plates 2, which are cooling bodies, are inserted in the blast furnace wall 1 in the height direction to cool and protect the furnace wall bricks. If one of the cooling panels 2 is damaged due to the high temperature inside the furnace and it is discovered too late, other cooling panels in the same cooling system will also be damaged due to water cutoff. Therefore, usually 3 to 5 cooling plates are installed in one
It is connected as a cooling system.

On the other hand, the cooling plate is equipped with approximately 7 lb.
A large amount of water is flowing at a rate of 5 to 1007/min.

Therefore, the amount of temperature rise is small and the wastewater temperature is approximately 6ρ℃.
It is as follows.

Drainage from each system is collected in a drainage annular pipe 3 provided on each floor, and further collected in a drainage tank 5 via a drainage main pipe 4. The water is then cooled by an air-cooled or seawater-cooled cooling equipment 6, and water is again supplied to the cooling board 2 via a pump 7, a main water supply pipe 8, and an annular water supply pipe 9.

FIG. 2 shows a system diagram of a one-type staple cooler type furnace body cooling system.

Since the required amount of water supply differs in the height direction, it is divided into three sections, and the staple coolers 10 are each connected in series with one pipe, and the drainage is discharged to the drainage tank 13 via the drainage annular pipe 11 and the drainage main pipe 12. Gather. Here, it is cooled by a seawater cooling type cooling equipment 14, and then sent to the staple cooler 10 via a pump 15, a main water supply pipe 16, and an annular water supply pipe 17.
Water will be supplied to the area again.

In either method, the cooling water temperature is as low as about 50'C or less.

For this reason, when thermal energy is recovered in a low boiling point heat medium turbine power generation system or the like, the capacity of the heat exchanger is large and the generated steam pressure of the low boiling point heat medium is low, resulting in a small amount of power generation.

Therefore, it is not economical and makes it difficult to recover the cooling and drainage thermal construction method.

FIG. 3 shows a system diagram of the cooling wastewater thermal energy recovery system in the case of the cooling plate type according to the present invention.

The temperature of the wastewater that has passed through the drainage main pipe 4 is raised by an absorption heat pump 18, and a part of the wastewater is taken out as high-temperature water of approximately 70°C or higher. The remainder of the wastewater is cooled and removed as low-temperature cooling water.

This type of heat pump is usually called an O-type absorption heat pump and consists of an evaporator 19, an absorber, a cooler 21, and a generator.

This method utilizes the exothermic effect called heat of absorption (heat of dilution) when an aqueous solution such as lithium bromide (LiBr) absorbs water vapor.

Other types of absorption heat pumps, compression heat pumps, etc. may be used to extract high temperature water.

These high-temperature waters are introduced into a low-boiling point heat medium steam generator in the low-boiling point heat medium turbine power generation equipment μs to generate low-boiling point steam, which rotates a turbine to recover energy as electric power.

Cooling provided in the blast furnace wall 1 via the low-temperature cooling water at one of the heat pump outlets, the cooling water cooled by the low boiling point heat medium steam generator, the 5 pump 7, the main water supply pipe 8, and the annular water supply pipe 9. Water is supplied to board 2 again. Note that 5 in the figure is a drainage tank.

As described above, the relatively low temperature blast furnace cooling water is converted into high temperature water suitable for low boiling point heat medium turbine power generation using a heat pump,
It becomes possible to recover cooling water waste heat by low boiling point heat medium turbine power generation.

As another method, to secure high temperature water suitable for low boiling point heat medium turbine power generation without using the heat pump 18
It is conceivable to connect many cooling bodies as one cooling channel.

The same applies to the cooling plate type and the staple cooling type.

With the long-term operation of a blast furnace, the amount of heat absorbed by the cooling water tends to increase.

Therefore, the exhaust heat recovery equipment of the present invention is extremely useful industrially.

[Brief explanation of drawings]

Figure 1 is a system diagram of a conventional cooling plate type furnace body cooling system, Figure 2 is a system diagram of a conventional stave cooling type furnace body cooling system, and Figure 3 is a diagram of the cooling wastewater thermal energy according to the present invention. It is a system diagram showing an example of a collection system. 1 is the blast furnace furnace wall, 2 is the cooling plate, 4 drainage mains, 5 is the drainage tank, 7 is the pump, 8 is the water supply main pipe, 9 is the water supply ring pipe, 1
8 is an absorption heat pump, 19 is an evaporator, and 19 is an absorber.
21 is a cooler, n is a generator, 23 is a low boiling point heat medium turbine power generation equipment, Sae is one low temperature cooling water, and 5 is cooling water cooled by a low boiling point heat medium steam generator. Patent applicant Nippon Steel Plant Design Co., Ltd. /
Concave reed, 4 boys, 3 boys (1

Claims (1)

[Claims] A blast furnace body cooling water exhaust heat recovery equipment, characterized in that a heat pump and a low boiling point heat medium power generation equipment are installed in the circulation path of cooling water and waste water in a blast furnace body cooling system.