EP3030364A1

EP3030364A1 - Utilisation of the heat contained in a cooling fluid

Info

Publication number: EP3030364A1
Application number: EP14747338.3A
Authority: EP
Inventors: Johannes Dagner; Martin Rössiger; Klaus Weinzierl
Original assignee: Primetals Technologies Germany GmbH
Current assignee: Primetals Technologies Germany GmbH
Priority date: 2013-08-06
Filing date: 2014-07-25
Publication date: 2016-06-15
Also published as: CN105682824A; WO2015018673A1

Abstract

A plant part (1 to 4) of a primary industry plant and/or a material (5) processed in the plant is cooled with a fluid (6). The fluid (6) is heated by the cooling of the plant part (1 to 4) and/or of the material (5) processed in the plant from a starting temperature (T1) to an end temperature (T2). Heat contained in the heated fluid (6) is used for preheating a material (5) to be processed subsequently in the plant and/or for preheating a process fluid (7, 8) used in the plant. The heat contained in the heated fluid (6) is fed to the material (5) to be processed subsequently in the plant and/or to the process fluid (7, 8) by means of a heat exchanger (10). The heat contained in the heated fluid (6) is initially emitted to an intermediate medium (11) in the heat exchanger (10). The material (5) to be processed subsequently in the plant and/or the process fluid (7, 8) used in the plant is heated by means of the intermediate medium (11). The heat contained in the heated fluid (6) is transferred by means of a transfer circuit (12) of the heat exchanger (10) and a heat pump (13) arranged in the transfer circuit (12) to the intermediate medium (11). The intermediate medium (11) is heated by means of the heat exchanger (10) to a heating temperature (T3) above the temperature at which the fluid (6) enters the heat exchanger (10).

Description

description

Use of the heat contained in a cooling fluid The present invention relates to an operating method for a plant of the basic industry,

- wherein a part of the system and / or a proces ^¬ tetes in the plant material is cooled with a fluid,

wherein the fluid is heated from an initial temperature to a final temperature by the cooling of the plant part and / or the material processed in the plant,

- In the heated fluid contained heat for the

Preheating a material to be later processed in the installation and / or for preheating a process fluid used in the installation,

wherein the heat contained in the heated fluid is supplied to the later to be processed in the system material and / or the process fluid via a heat exchanger,

- Wherein the heat contained in the heated fluid is first discharged into the heat exchanger to an intermediate medium and the material to be processed later in the system and / or the process fluid used in the system is heated by means of the intermediate medium. Such systems are well known. For example, in the continuous casting of metal, the mold is cooled with water. Furthermore, when rolling metal and after rolling metal - especially if the metal is strip-shaped - the rolled metal is often between the individual rolling stands of a multi-stand rolling train and / or in one of

Rolling mill downstream cooling section cooled. The Wal ^¬ zen of the rolling stands are often cooled, either for Küh ^¬ development as such, except for the targeted control of the crowning. In other processes, a heated fluid is generated to a considerable extent. Purely by way of example

Scale scrubbers during hot rolling, cooling in the range of furnaces (for example a slab furnace) and hot-dip galvanizing plants. In all these cases falls in considerable Circumference to a heated fluid. The fluid used for cooling often has a final temperature in the heated state, which is only slightly above the initial temperature and / or the ambient temperature. For example, the heated to cooling a metal strip in a cooling zone ver ^¬ applied cooling water often only about 10 ° C.

From DD 28 781 plants are known which consist of three Wärmezo ^¬ NEN, in which the rolling stock preheated, heated to the final ^¬ temperature and then cooled. The recovered during cooling of the expiring rolled good warm air is supplied by means of transverse fans cold incoming rolling stock for preheating.

DE 29 51 379 Al is known that in many indus ^{¬-industrial} processes - are known as hardening, annealing and brazing - cooling facilities are required and that it is possible that the cooling liquid has a low temperature level. The resulting heat loss is fed via a heat exchanger ei ^¬ nem buffer memory. The stored heat in the buffer memory can later be returned to consumers such as heat treatment facilities.

From DE 32 25 403 AI a relatively complicated heating and cooling process is known, in which inter alia, a heat ^¬ recovery by condensation of steam takes place. The recovered heat is used to preheat the material to be treated.

From DE 10 2010 052 423 Al an operating method for a plant of the basic industry is known, wherein a Anla ^¬ genteil is cooled with a fluid, wherein the fluid is heated by the cooling of the plant part of an initial temperature to a final temperature. The heat contained in the heated fluid is generally recycled. It is also mentioned that the recovered energy as part of a process heat management system can further be used ^¬. From WO 2010/099 920 A2 an operating method for a plant of the basic industry is known, in which a plant ^¬ part and / or processed in the plant material is cooled with a fluid, wherein the fluid is thereby heated. The heat contained in the fluid is supplied via a heat ^¬ exchanger to a later to be processed in the plant material or used through the heat exchanger for the preparation of a process fluid used in the system. The fluid can be reheated.

From WO 2013/013 788 AI an operating method for a plant of the basic industry is known, wherein a plant part is cooled with a fluid, wherein the fluid is heated by the cooling of the plant part of an initial temperature to a final temperature. The heat contained in the heated fluid is used for the generation of electric current. For this purpose, a thermoelectric generator whose structure and mode of action is not explained in detail. The object of the present invention is to provide ways to efficiently utilize the thermal energy contained in the heated fluid.

The object is achieved by an operating method with the features of claim 1. Advantageous embodiments of the operating ^method according to the invention are the subject of dependent claims 2 to 8.

According to the invention, an operating method of the type mentioned above is configured by transferring the heat contained in the heated fluid via a transfer circuit of the heat exchanger and a heat pump arranged in the transfer circuit to the intermediate medium and by heating the intermediate medium to a heating temperature by means of the heat exchanger which is above the temperature at which the fluid enters the heat exchanger. The plant can be, for example, a plant of metallerzeu ^¬ ing or the metalworking industry. In particular, the installation may comprise a foundry, a rolling mill and / or a cooling section downstream of a rolling mill. Examples game as the piece of equipment can be a mold of a continuous casting plant ^¬ or a roll stand of the rolling mill. Same ^¬ reasonably can - purely exemplary - the material be a metal band. In some cases, it is possible that the fluid is a gas.

In general, however, the fluid is a liquid, insbeson ^¬ particular a water-based liquid.

The material to be later processed in the plant can be, for example, a metal or a metal ore. That in the

Conditioning process fluid used may be (in particular air), for example, a burning ^¬ bares medium and / or a material used for the combustion of the combustible medium oxidizing gas. The heat pump can be operated, for example, with electrical or thermal energy. Preferably, during operation of the heat pump resulting waste heat is used in a further heat exchanger to increase the heating temperature of the intermediate medium.

The above-described characteristics, features and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments which will be described in detail in conjunction with the drawings. Here are shown in a schematic representation:

1 to 3 possible embodiments of systems of

Basic industry.

According to FIGS. 1 and 2, a plant of the basic industry has several plant parts 1 to 4, which are passed through in succession by a material 5 to be processed. At installation of basic industry can be at ^¬ play, be a system of metal production and metalworking. Such systems are, for example, melting devices in which metal is recovered from metal ore and / or scrap. Melting devices are, for example, electric arc furnaces, smelting reduction plants and the like. Likewise, such plants are casting facilities in which the molten metal is poured into a mold or strand. A typical example of a casting device is a continuous casting plant. Likewise, such plants are rolling mills and the like more, for example ^¬ Vorstraßen or finishing lines. The processed in the respective rolling mill material may be bandför ^¬ mig, rod-shaped, tubular, etc..

For example, in a combined casting and rolling (FIG 1) of the installation part 1 may be a continuous casting mold, the Appendices ^¬ contrary 2, a strand guide, the bearing part 3, a furnace and the installation part 4, a rolling mill with or without a downstream cooling zone. For example, in a rolling mill (FIG. 2), the plant part 1 may be a slab bearing, the plant part 2 an oven, the plant part 3 a number of rolling stands, and the plant part 4 a cooling line. Other ^{Ausgestaltun ¬} conditions are possible. For example, the individual parts of the system may have 1 to 3 are each a roll ^¬ correspond scaffold of the rolling mill, the plant part 4 alterna tive ^¬ a further rolling mill or a cooling section. In the case of a rolling mill The number of plant parts 1 to 4 may vary depending on the location of the case.

As a rule, at least one of the plant parts 1 to 4 is cooled with a fluid 6. Most of the fluid 6 is a water-based liquid, that is, either more or less pure water or water, the additives are admixed, for example, a water-oil emulsion. For example, in a continuous casting the casting mold 1 is cooled in it ^¬ considerable quantities of water. In a rolling mill, rolls of rolling stands are replaced with water or a water-oil mill. Emulsion cooled and / or lubricated. Another example is the cooling of rollers of a roller table.

Alternatively or additionally, for cooling at least one plant-gene part 1 to 4 is often cooled in at least one of Appendices ^¬ gene portions 1 to 4, the processed in the plant material 5 with the fluid. 6 For example, in the strand guide 2 ^¬ a continuous casting of the cast metal strand 5 is cooled to a significant extent with water. Similarly, a rolled metal strip 5 is often cooled between rolling stands ei ^¬ ner rolling mill and / or in a rolling mill downstream ^¬ th cooling section to a considerable extent with water. Depending on the situation of the individual case, other embodiments are possible, for example cooling with an oil or cooling with a gas.

By cooling the (at least one) part of the plant 1 to 4 and / or of the material 5 processed in the plant, the fluid 6 is heated from an initial temperature T 1 to a final temperature T 2. A difference between the end temperature T2 and the initial temperature Tl and also an ambient temperature TU is often relatively low. For example, the initial temperature T1 may be about 5 ° C to about 40 ° C, the ambient temperature TU at about 0 ° C to about 30 ° C and the final temperature about 10 ° C to about 25 ° C. above the initial temperature Tl and / or the ambient temperature TU. Due to the accumulated amount of heated fluid 6, the total amount of heat ^¬ accumulation is relatively large. According to the invention, the heat contained in the heated fluid 6 is not released to the environment, but utilized specifically.

For example, the heat contained in the heated fluid 6 can be used for the preheating of a later to be processed in the plant 5 material. This is Example ^¬ example of FIG 2, characterized appreciated that the fluid is supplied to the slabs 6 camp 1. In the slab bearing 1 located Slabs 5 are thereby pre-heated for example by the ambient temperature TA (for example, 0 ° C to 20 ° C) to a higher temperature Tem ^¬ for example 20 ° C to 40 ° C. A similar procedure is possible if the system is coupled according to FIG 1 with a smelting device and preheated before the smelting process iron ore or other metal ore.

As an alternative or in addition to the preheating of a material 5 to be later processed in the system, the heat contained in the heated fluid 6 can be used to preheat a process fluid 7, 8 used in the system. When it is operated, for example within the plant, a coal, coke, oil or gas burner 9, have the burner 9 as process fluids 7, 8 on the one hand the appropriate combustible Me ^¬ dium 7 and on the other hand a material used for the combustion of the combustible medium 7 oxidizing gas 8 (for example, air) are led to ^¬ . These media or process fluids 7, 8 can also be preheated by means of the heated fluid 6.

The heat contained in the heated fluid 6 is the later to be processed in the plant material 5 and / or the product zessfluid 7, 8 supplied ^¬ results shown in FIG 3 via a heat exchanger 10 degrees. Furthermore, the heat contained in the heated fluid 6 is discharged in the heat exchanger 10 to an intermediate medium 11. The material 5 to be subsequently processed in the system and / or the process fluid 7, 8 used in the system is heated by means of the intermediate medium 11. The intermediate medium 11 may be a gas or a liquid, depending on the location of the individual case. In general, it will han spindles ^¬ a liquid.

The heat exchanger 10 has its own transmission circuit 12 and a heat pump 13 arranged in the transmission circuit 12. The heat contained in the heated fluid 6 is transferred to the intermediate medium 11 via the transmission circuit 12 and the heat pump 13. By this embodiment, it is particularly possible that the intermediate medium 11th is further heated by the heat exchanger 10. Ins ^¬ particular, the intermediate medium 11 can be heated by the Wärmetau ^¬ shear 10 to a heating temperature T3 above the Endtempera ^¬ temperature T2. In any case - especially if the fluid 6 should have cooled significantly on the way from the system parts 3, 4 to the heat exchanger 10 - but there is a heating to a temperature above that temperature at which the fluid 6 enters the heat exchanger 10. The heating temperature T3, for example, in water as an intermediate medium 11 scarce (maximum 10% to 15%) below the boiling temperature of the intermediate medium 11 are. The boiling ^¬ temperature, which is usually 100 ° C in water, may optionally be above 100 ° C, if the intermediate ^¬ medium 11 is subjected to a higher pressure.

Regardless of whether the heat pump 13 is operated by means of thermal or electrical energy, falls during operation of the heat pump 13 waste heat 14 at. Under certain circumstances, the waste heat 14 can be used to increase the heating temperature T3 of the intermediate medium 11 in a further heat exchanger 15 to a value which is above the value at which the intermediate medium 11 emerges from the heat exchanger 10, the transmission circuit 12 and the Heat pump 13 contains. The illustration in FIG. 3 is an embodiment of the plant of the basic industry of FIG. 2. However, a corresponding embodiment is likewise possible in the plant of the basic industry of FIG. The present invention has many advantages. Insbeson ^¬ particular can be made the use of the thermal energy contained in the heated fluid 6 in spite of the relatively low temperatures Tl, T2 of the fluid. 6 C02 emissions can be reduced as a result. Also, cost savings can be achieved.

As a result, according to the invention, a plant part 1 to 4 egg ^¬ ner plant of the basic industries and / or in the plant processed material 5 cooled with a fluid 6. The fluid 6 is heated by cooling the system part 1 to 4 and / or the material 5 processed in the system from an initial temperature T 1 to a final temperature T 2. Heat contained in the heated fluid 6 is used for preheating a material 5 to be later processed in the installation and / or for preheating a process fluid 7, 8 used in the installation. The heat contained in the heated fluid 6 is supplied to the plant in the later proces ^¬ tendem material 5 and / or the process fluid via a heat exchanger 7 8 10th The heat contained in the heated fluid 6 is first released in the heat exchanger 10 to an intermediate medium 11. The later to be processed in the plant material 5 and / or the process fluid 7 used in the system, 8 it warms ^¬ by means of the intermediate medium. 11 The heat contained in the heated fluid 6 is transmitted to the intermediate medium 11 via a transmission circuit 12 of the heat exchanger 10 and a heat pump 13 arranged in the transmission circuit 12. The intermediate medium 11 is heated it ^¬ by means of heat exchanger 10 to a heating temperature T3 that is above the temperature at which the fluid 6 entering the heat exchanger 10 degrees.

Although the invention in detail by the preferred embodiment has been illustrated and described in detail, the invention is not limited ^¬ by the disclosed examples and other variations can be derived therefrom by the skilled artisan without departing from the scope of the invention.

Claims

claims

1. operating procedure for a plant of the basic industry,

wherein a plant part (1 to 4) and / or a material (5) processed in the plant is cooled with a fluid (6),

wherein the fluid (6) is heated from an initial temperature (Tl) to an end temperature (T2) by cooling the plant part (1 to 4) and / or the material (5) processed in the plant,

wherein heat contained in the heated fluid (6) is used for preheating a material (5) to be subsequently processed in the installation and / or for preheating a process fluid (7, 8) used in the installation,

wherein the heat contained in the heated fluid (6) is supplied to the material (5) to be subsequently processed in the installation and / or the process fluid (7, 8) via a heat exchanger (10),

- Wherein the heat contained in the heated fluid (6) in the heat exchanger (10) is first delivered to an intermediate medium (11) and later in the plant to be processed material (5) and / or the process fluid used in the system ^¬ (7, 8) is heated by means of the intermediate medium (11),

characterized ,

the heat contained in the heated fluid (6) is transferred to the intermediate medium (11) via a transmission ^circuit (12) of the heat exchanger (10) and a heat pump (13) arranged in the transmission circuit (12) to the intermediate medium (11) and in that the intermediate medium (11 ) is heated by means of the heat exchanger (10) to a heating temperature (T3) which is above the temperature at which the fluid (6) enters the heat exchanger (10).

2. Operating method according to claim 1,

characterized ,

that the installation is an installation of the metal-producing or the metalworking industry.

3. Operating method according to claim 2,

characterized ,

that / the plant has a foundry, a mill and an egg or ^¬ nem rolling mill comprises downstream cooling section.

4. Operating method according to claim 3,

characterized ,

that the plant part (1 to 4) is a mold of a continuous casting ^¬ plant or a roll stand of the rolling mill and / or that the material (5) is a metal strip.

5. Operating method according to one of the above claims, d a c e c o v e c e n e c e n e,

the fluid (6) is a gas or a liquid.

6. Operating method according to claim 5,

characterized ,

the fluid (6) is a water-based fluid.

7. Operating method according to one of the above claims, d a a c e c e s e c e n e c e,

the material (5) to be subsequently processed in the installation is a metal or a metal ore and / or that the process fluid (7, 8) used in the installation comprises a combustible medium (7) and / or a combustible medium (7) ) used oxidizing gas (8).

8. Operating method according to one of the above claims, d a d u c h e c e n e c e n e,

that the heat pump (13) by means of thermal or electrical ^¬ shear energy is operating and that during operation of the heat ^¬ pump (13), waste heat (14) in a further heat ^¬ exchanger (15) to increase the heating temperature (T3) of the intermediate medium (11).