CN106052405A - Heating furnace waste heat comprehensive utilization system and method - Google Patents

Abstract

The invention discloses a system for comprehensive utilization of waste heat of a heating furnace, comprising: a steam superheater arranged in the flue of the heating furnace, the low-pressure saturated steam generated by the vaporization cooling system of the heating furnace flows into the steam superheater, and the flue gas of the heating furnace can be used for the low-pressure saturated steam Heating to generate superheated steam; generator set, which is in fluid communication with the steam superheater, and the superheated steam generated in the steam superheater flows into the generator set to generate electricity; seawater desalination device, which is in fluid communication with the generator set, and the steam discharged from the generator set flows into Seawater desalination device for desalination of seawater. The invention also discloses a method for comprehensively utilizing waste heat of a heating furnace. The invention fully realizes the cascade utilization of the steam energy of the heating furnace, not only utilizes the steam residual pressure to generate electricity, but also utilizes the steam residual heat to produce fresh water.

Description

System and method for comprehensive utilization of heating furnace waste heat

technical field

The invention relates to a comprehensive utilization system and method for waste heat of a heating furnace, belonging to the fields of waste heat utilization, seawater desalination and flue gas purification.

Background technique

The energy consumption of China's iron and steel industry accounts for about 16% of the country's total energy consumption, which is a high-energy-consuming industry. The energy consumption of the steel rolling process accounts for 10% to 20% of the total metallurgical energy consumption, and the energy consumption of the heating furnace accounts for about 65% to 80% of the steel rolling process. The heating furnace is the most important energy-consuming equipment in the steel rolling process. The rated unit consumption of the heating furnace is 1.1-1.5GJ/t, and the thermal efficiency of the heating furnace is generally 45%-60%.

Among them, after the flue gas from the heating furnace passes through the air/gas heat exchanger, the temperature of the flue gas is above 300°C, and the heat taken away by the flue gas accounts for 25% to 40% of the total heat, which has a great potential for energy saving. In addition, the heating furnace flue gas also contains SO ₂ , NO _x , particulate matter, etc. Studies have shown that SO ₂ , NO _x , and particulate matter are the main factors that form smog. At present, the flue gas from the heating furnace is generally discharged directly into the atmosphere through the chimney without any purification treatment, which is very harmful to the environment.

The heating furnace adopts vaporization cooling technology to cool the walking beam in the furnace and generate steam, and recover part of the waste heat of the heating furnace. Evaporative cooling technology reduces the problem of large amount of circulating cooling water in the heating furnace, and at the same time reduces the power consumption of circulating cooling water, realizing energy saving. High-temperature, high-pressure, large-flow, and stable steam is a high-quality heat source. Domestic steam turbine power generation technology is very mature, but the distribution of heating furnaces in iron and steel plants is scattered, and the quality of steam generated by vaporization and cooling of heating furnaces is low. The output of heating furnace fluctuates greatly, so it is not suitable to use steam turbine power generation technology.

At the same time, the use of low-pressure steam generated by the vaporization cooling system of the heating furnace is restricted. Heating in winter causes a serious depreciation of steam quality, and the large amount of steam released in summer causes huge waste. In addition, the low-pressure steam generated by the heating furnace has a large heat loss during long-distance transportation. Similar problems are common in other industrial fields in my country. A large number of low-quality steam waste heat resources have not been efficiently utilized, which wastes energy and pollutes the environment.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and provide a system and method for comprehensive utilization of waste heat of heating furnaces, which connects the heating furnace vaporization cooling system, screw expander generator set, and low-temperature multi-effect distillation seawater desalination device in series, and utilizes steam by stages The energy is used to realize the purpose of power generation and seawater desalination, and the waste heat of the heating furnace flue gas is further utilized to realize the purification treatment of the heating furnace flue gas.

In order to achieve the above purpose, the specific technical scheme of a system and method for comprehensive utilization of waste heat of heating furnace in the present invention is as follows:

A heating furnace waste heat comprehensive utilization system, comprising: a steam superheater, which is arranged in the flue of the heating furnace, and the low-pressure saturated steam generated by the heating furnace vaporization cooling system flows into the steam superheater, and the flue gas of the heating furnace can heat the low-pressure saturated steam to Superheated steam is generated; the generator set is in fluid communication with the steam superheater, and the superheated steam generated in the steam superheater flows into the generator set for power generation; the seawater desalination device is in fluid communication with the generator set, and the steam discharged from the generator set flows into the seawater desalination device , for desalination of seawater.

Further, it also includes: a flue gas cooler, arranged in the flue of the heating furnace, the pretreated seawater flows into the flue gas cooler, the flue gas from the heating furnace can heat the pretreated seawater, and the pretreated seawater with increased temperature flows into the seawater desalination device.

Further, it also includes: a dust collector, the flue gas of the heating furnace flows into the dust collector for dust removal; the desulfurization tower, the internal spray system is in fluid communication with the seawater desalination device, and the concentrated brine generated in the seawater desalination device flows into the spray system, after dust removal The flue gas flows into the desulfurization tower, and the concentrated brine washes and desulfurizes the flue gas.

Further, the generator set is a screw expander generator set.

Further, the seawater desalination device is a low-temperature multi-effect distillation seawater desalination device.

Further, the steam outlet of the steam superheater is connected with the steam inlet of the screw expander generator set through a steam pipeline, and the steam pipeline is provided with a valve, a steam trap, a temperature detection device, a pressure detection device, and a flow detection device in sequence.

Furthermore, the steam outlet of the screw expander generator set is connected to the steam inlet of the low-temperature multi-effect distillation seawater desalination device through a steam pipeline, and the steam pipeline is sequentially equipped with a pressure detection device, a steam desuperheater, a release device, a valve, a drain device, temperature detection device, pressure detection device, flow detection device.

A method for comprehensive utilization of waste heat of a heating furnace, comprising the following steps: exchanging heat between the flue gas of the heating furnace and the low-pressure saturated steam generated by the vaporization cooling system of the heating furnace, the temperature of the flue gas of the heating furnace is lowered, and the low-pressure saturated steam becomes superheated steam; The superheated steam is sent to the screw expander generator set for power generation; the steam discharged from the screw expander generator set is sent to the low-temperature multi-effect distillation seawater desalination device for seawater desalination.

Further, the method further includes the following steps: heating the pretreated seawater with the flue gas of the heating furnace after heat exchange with the low-pressure saturated steam; and transporting the pretreated seawater with increased temperature to a low-temperature multi-effect distillation seawater desalination device for seawater desalination.

Further, the method further includes the following steps: removing dust and desulfurizing the flue gas from the heating furnace and then discharging it; during the desulfurization process, the flue gas from the heating furnace can be washed and desulfurized by using the concentrated brine produced in the seawater desalination process.

The comprehensive utilization system and method of heating furnace waste heat of the present invention have the following advantages:

1) The present invention fully realizes the cascade utilization of the steam energy of the heating furnace, not only utilizing steam residual pressure to generate electricity, but also utilizing steam residual heat to produce fresh water.

2) The present invention utilizes the heating furnace steam to generate electricity nearby, which solves the adverse effect of the unstable steam flow rate of the heating furnace on power generation. Compared with steam turbine power generation, the screw expander, as a kind of rotary machine, has a large range of heat source load and parameters (30% -120%) fluctuations, not only the operation is stable, but also the power generation can be automatically adjusted to adapt to the unstable working conditions of the steam flow of the heating furnace.

3) The present invention uses heating furnace steam to desalinate seawater nearby, which reduces the energy consumption and cost of low-temperature multi-effect distillation seawater desalination. Seawater desalination is an energy-intensive industry, and low-temperature multi-effect distillation is an improved technology of multi-effect distillation It is characterized by low pretreatment requirements for raw seawater, low operating temperature, low process cycle power consumption, large system capacity flexibility (40%-110%), and high quality fresh water produced. Now low-temperature multi-effect distillation is mostly used High-temperature and high-pressure power steam is used as a heat source. The high cost of high-temperature and high-pressure steam leads to high water production costs. Using low-grade steam as a heat source will be one of the directions for low-temperature multi-effect distillation seawater desalination.

4) The present invention realizes the combined production of heat, electricity and water in metallurgical heating furnaces, and has remarkable social and economic benefits. Due to the low power consumption of low-temperature multi-effect distillation seawater desalination, the electric energy generated by the screw expander generator set is far enough to meet the requirements of low-temperature multi-effect seawater desalination. In addition, the fresh water produced by the low-temperature multi-effect distillation method has high purity and is suitable for direct use as makeup water for steam drums and boilers, or for other users.

5) The present invention realizes the deep purification of the flue gas of the heating furnace, and the emission index of the flue gas is higher than the national and local standards.

Description of drawings

Fig. 1 is the process flow diagram of the heating furnace waste heat comprehensive utilization system of the present invention;

Fig. 2 is a working principle diagram of using low-pressure steam for power generation and seawater desalination in the comprehensive utilization system of heating furnace waste heat of the present invention.

detailed description

In order to better understand the purpose, structure and function of the present invention, a system and method for comprehensive utilization of heating furnace waste heat of the present invention will be further described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1 and Figure 2, the comprehensive utilization system of heating furnace waste heat of the present invention includes: steam superheater 12, flue gas cooler 13, screw expander generator set 2, low temperature multi-effect distillation seawater desalination device 3, dust collector, Desulfurization tower.

Further, the steam superheater 12 is arranged in the flue of the heating furnace, and the low-pressure saturated steam generated by the vaporization cooling system 1 of the heating furnace flows into the steam superheater 12, and the flue gas of the heating furnace can heat the low-pressure saturated steam to generate superheated steam. Specifically, the steam outlet of the heating furnace evaporative cooling system 1 is connected to the steam inlet of the steam superheater 12 through the steam pipe 4, and the steam pipe 4 is provided with a valve 5, and the steam generated by the heating furnace evaporative cooling system 1 enters through the steam pipe 4. Steam superheater 12. It should be noted that the pressure of the saturated steam generated by the evaporative cooling system 1 of the heating furnace is controlled to be 0.2-1.27 MPa(G), and the pressure loss of the saturated steam passing through the steam superheater 12 is <15%.

Further, the flue gas cooler 13 is arranged in the flue of the heating furnace, behind the steam superheater 12, the pretreated seawater flows into the flue gas cooler 13, the flue gas from the heating furnace can heat the pretreated seawater, and the pretreatment of the temperature rise Seawater flows into the desalination unit. Specifically, the pretreated seawater that meets the water quality requirements of seawater desalination absorbs part of the waste heat of the flue gas through the flue gas cooler 13 before desalination, and the temperature of the pretreated seawater after heat exchange is >25°C.

Further, the screw expander generator set 2 is in fluid communication with the steam superheater 12, and the superheated steam generated in the steam superheater 12 flows into the screw expander generator set 2 to generate electricity. Specifically, the steam outlet of the steam superheater 12 is connected to the steam inlet of the screw expander generator set 2 through the steam pipeline 4, and the steam pipeline 4 is provided with a valve 5, a steam trap 6, a temperature detection device 7, and a pressure detection device in sequence. 8. The flow detection device 9, wherein the valve 5 can be closed and controlled to adjust the steam flow rate entering the screw expander, and the steam trap 6 can get rid of the condensed water produced by the steam pipeline 4 in this section and prevent steam leakage at the same time (preferably, the steam pipeline 4 Multiple steam traps can be set 6).

Furthermore, the work done by the screw expander consists of three processes: steam intake, expansion, and steam exhaust. The steam enters the screw expander to expand and perform work, thereby driving the power machine and generator to generate electricity. The screw expander generator set 2 mainly uses the pressure of the steam generated by the heating furnace. and part of the thermal energy conversion to generate power, in order to improve the power generation efficiency, the multi-stage screw expander generator set 2 can be connected in series.

Further, the temperature detection device 7, the pressure detection device 8, and the flow detection device 9 are arranged near the steam inlet of the screw expander generator set 2, and the temperature detection device 7, the pressure detection device 8 and the flow detection device 9 can detect the steam entering the screw expander in real time. The steam working condition of the engine generator set 2 is fed back to the screw expander generator set 2 to achieve the purpose of controlling the speed of the engine generator and adjusting the power.

Further, the low-temperature multi-effect distillation seawater desalination device 3 is in fluid communication with the generator set, and the steam discharged from the generator set flows into the seawater desalination device as a heat source for seawater desalination to perform seawater desalination. Specifically, the steam outlet of the screw expander generator set 2 is connected to the steam inlet of the low-temperature multi-effect distillation seawater desalination device 3 through a steam pipeline 4, and the steam pipeline 4 is provided with a pressure detection device 8 and a steam desuperheater in sequence. 10. Dispersion device 11, valve 5, steam trap 6, temperature detection device 7, pressure detection device 8, flow detection device 9, wherein, the steam desuperheating and pressure reducing device 10 can reduce the temperature and decompression of the steam discharged from the screw expander to It is suitable for the temperature and pressure required by the low-temperature multi-effect distillation. The valve 5 can be closed to control and adjust the steam flow rate entering the low-temperature multi-effect distillation seawater desalination device 3. The discharge device 11 can directly discharge the steam discharged from the screw expander into the atmosphere (normal conditions The lower diffuser 11 is in a closed state), and the steam trap 6 can quickly get rid of the condensed water produced by this section of the steam pipeline 4 and prevent steam leakage (preferably, the steam pipeline 4 can be provided with multiple steam traps 6).

Further, the steam pressure discharged from the screw expander generator set 2 is <0.121MPa(A), and after this part of the steam passes through the steam desuperheater 10, the steam pressure is <0.0419MPa(A), and the steam temperature is <77°C. The heat loss of the steam pipeline 4, when the steam enters the inlet of the low-temperature multi-effect distillation seawater desalination device 3, the steam temperature is ≤70°C, and the steam evaporates and condenses multiple times in the low-temperature multi-effect distillation seawater desalination device 3, thereby desalinating the pretreated seawater, Fresh water that is multiple times the amount of steam is obtained, and the fresh water produced is delivered to users through pumps and pipe networks.

Further, the temperature detection device 7, the pressure detection device 8, and the flow detection device 9 are arranged near the steam inlet of the low-temperature multi-effect distillation seawater desalination device 3, and the temperature detection device 7, the pressure detection device 8 and the flow detection device 9 can detect in real time The steam working condition of the low-temperature multi-effect distillation seawater desalination device 3 , the low-temperature multi-effect distillation seawater desalination device 3 controls the amount of seawater entering the seawater desalination device according to the feedback steam parameter signal to adjust the production of fresh water.

Further, the dust remover and the desulfurization tower are arranged behind the flue gas cooler 13, and the flue gas from the heating furnace flows into the dust remover for dust removal; the spray system inside the desulfurization tower is in fluid communication with the seawater desalination device, and the concentrated water produced in the seawater desalination device is The brine flows into the sprinkler system, the dust-removed flue gas flows into the desulfurization tower, and the concentrated brine washes and desulfurizes the flue gas. Specifically, seawater is usually alkaline, with a pH value of 7.8-8.3. The concentrated brine produced after seawater desalination is more alkaline and has a stronger ability to absorb sulfur dioxide. In addition, the alkaline brine can also partially absorb the sulfur dioxide in the flue gas. NOx and fine particles can achieve the effect of deep purification of flue gas. Thus, in the desulfurization tower, the concentrated brine produced by seawater desalination washes the low-temperature flue gas of the heating furnace countercurrently by spraying and spraying. Most of the sulfur dioxide gas in the flue gas is absorbed by the concentrated brine to generate sulfite ions and hydrogen ions. The pH value of the washing liquid decreases, and at the same time, the bicarbonate ions in the concentrated brine can react with the hydrogen ions to generate water and carbon dioxide, thereby preventing or alleviating the continued decline in the pH value of the washing liquid, which is beneficial to the continued reduction of sulfur dioxide in the concentrated brine. The concentrated brine after absorption and desulfurization treatment can be neutralized with alkaline industrial waste residue or wastewater.

As shown in Figure 1 and Figure 2, the comprehensive utilization method of heating furnace waste heat of the present invention comprises the following steps:

First, heat exchange is performed between the flue gas of the heating furnace and the low-pressure saturated steam generated by the vaporization cooling system 1 of the heating furnace, the temperature of the flue gas of the heating furnace is lowered, and the low-pressure saturated steam becomes superheated steam.

Specifically, after the flue gas from the heating furnace is discharged from the heating furnace, it first passes through the original air/gas heat exchanger to preheat the air/gas, the temperature of the flue gas decreases, and a steam superheater 12 is installed in the flue of the heating furnace. 12 is installed after the air/gas heat exchanger, and the flue gas passes through the steam superheater 12 to heat the low-pressure saturated steam produced by the heating furnace vaporization cooling system 1, and the temperature of the flue gas is further reduced.

Secondly, the pretreated seawater is heated by the flue gas of the heating furnace after heat exchange with the low-pressure saturated steam, and the pretreated seawater with elevated temperature is transported to the low-temperature multi-effect distillation seawater desalination device 3 for seawater desalination.

Specifically, a flue gas cooler 13 is installed after the steam superheater 12. The flue gas passes through the flue gas cooler 13 to heat the pretreated seawater at normal temperature, the temperature of the flue gas decreases, and the temperature of the pretreated seawater increases. The treated seawater enters the low-temperature multi-effect distillation seawater desalination device 3 for desalination.

Next, the generated superheated steam is sent to the screw expander generator set 2 to generate electricity.

Next, the steam discharged from the screw expander generator set 2 is sent to the low-temperature multi-effect distillation seawater desalination device 3 for seawater desalination.

At the same time, the flue gas from the heating furnace is discharged after dedusting and desulfurization. During the desulfurization process, the concentrated brine produced in the seawater desalination process can be used to wash and desulfurize the flue gas from the heating furnace.

Specifically, the low-temperature flue gas enters the dust collector and the desulfurization tower in turn, and the purified flue gas is discharged into the atmosphere by the induced draft fan; all or part of the concentrated brine produced by seawater desalination is used in the desulfurization tower to wash the flue gas of the heating furnace. The flue gas is desulfurized, and the concentrated brine after desulfurization is neutralized to adjust the water quality.

The system and method for comprehensive utilization of waste heat of the heating furnace fully realize the cascade utilization of the steam energy of the heating furnace, and not only use the steam residual pressure to generate electricity, but also use the steam waste heat to produce fresh water.

Specific examples:

For a heating furnace with a rated output of 180t/h, the exhaust gas temperature at the furnace tail is about 700°C. An air heat exchanger is installed in the flue of the heating furnace. The flue gas passes through the air heat exchanger to preheat the combustion-supporting air. The temperature of the flue gas after the heat exchanger It is about 450°C. The rated saturated steam output of heating furnace vaporization cooling system 1 is 5.5t/h, and the steam pressure is 0.9MPa(G).

A steam superheater 12 is installed after the air heat exchanger, and the flue gas temperature after the steam superheater 12 is <350°C; a flue gas cooler 13 is installed after the steam superheater 12, and the flue gas temperature after the flue gas cooler 13 is <220°C ℃, the pretreatment seawater temperature rises from normal temperature to about 35 ℃; the low-temperature flue gas after the flue gas cooler 13 enters the bag filter for dust removal; the flue gas after dust removal enters the desulfurization tower and is washed and desulfurized by concentrated brine; The flue gas is discharged into the atmosphere by the induced draft fan; the steam heated by the steam superheater 12 enters the screw expander generator set 2 and the low-temperature multi-effect distillation seawater desalination device 3 for power generation and seawater desalination; the heated pretreated seawater enters the low-temperature multi-effect The distilled seawater desalination device 3 performs desalination; part of the concentrated brine produced by seawater desalination is used to wash the flue gas, and the concentrated brine after desulfurization treatment is treated by neutralizing the blast furnace slag water, which contains CaO, SiO ₂ , MgO, Al ₂ O ₃ and a small amount of Fe ₂ O ₃ , the pH value is greater than 7, which is weakly alkaline, the blast furnace slag flushing water has a large amount of water, and the pH value fluctuation range is small, and it is suitable for neutralization treatment with acidic concentrated brine.

The steam generated by the heating furnace vaporization cooling system 1 enters the steam superheater 12, the screw expander generator set 2, and the low-temperature multi-effect distillation seawater desalination device 3 through the steam pipeline 4 in sequence. The low-pressure steam enters the screw expander generator set 2 for power generation, and then enters the low-temperature multi-effect distillation seawater desalination device 3 for seawater desalination, and the pressure and thermal energy of the steam are fully utilized. The steam outlet of the heating furnace evaporative cooling system 1 is connected to the inlet of the steam superheater 12 through a steam pipeline 4 , and the steam pipeline 4 is provided with a valve 5 . The outlet of the steam superheater 12 is connected to the steam inlet of the screw expander generator set 2 through the steam pipeline 4, and the steam pipeline 4 is provided with a valve 5, a steam trap 6, a temperature detection device 7, a pressure detection device 8, and a flow detection device 9. Open the valve 5 on the steam pipeline 4, and the steam generated by the vaporization cooling system 1 of the heating furnace can enter the screw expander generator set 2. The temperature detection device 7 , the pressure detection device 8 and the flow detection device 9 can detect the operating conditions of the steam entering the screw expander generator set 2 in real time. The screw expander generator set 2 adjusts the generating power of the set according to the feedback steam parameter signal.

The steam outlet of the screw expander generator set 2 is connected to the steam inlet of the low-temperature multi-effect distillation seawater desalination device 3 through a steam pipeline 4 . On the steam pipeline 4 of the screw expander generator set 2 and the low-temperature multi-effect distillation seawater desalination device 3, a pressure detection device 8, a steam desuperheater 10, a release device 11, a valve 5, a steam trap 6, a temperature Detection device 7, pressure detection device 8, flow detection device 9. The steam from the heating furnace enters the screw expander to push the screw to expand and do work, thereby driving the power machine and generator to generate electricity. The rated net generating power of screw expander generator set 2 is ~360kW. After the steam expands and works, the pressure is reduced to 0.108MPa(A), and it is discharged from the screw expander generator set 2.

On the steam pipeline 4 of the screw expander generator set 2 and the low-temperature multi-effect distillation seawater desalination device 3, a pressure detection device 8, a steam desuperheater 10, a release device 11, a valve 5, a steam trap 6, a temperature Detection device 7, pressure detection device 8, flow detection device 9. Under normal circumstances, the release device 11 is in a closed state. When the seawater desalination device is overhauled, the valve 5 can be closed, and the steam discharged from the screw expander is directly discharged into the atmosphere through the dispersing device 11 for release.

After the 0.108MPa(A) steam passes through the steam desuperheater 10, the steam pressure is <0.032MPa(A), and the steam temperature is <71°C. Considering the heat loss of the steam, when the steam enters the inlet of the low-temperature multi-effect distillation seawater desalination device 3 Steam temperature ≤70°C.

The low-temperature steam is evaporated and condensed multiple times in the low-temperature multi-effect distillation seawater desalination device 3, thereby desalinating the pretreated seawater to obtain fresh water that is multiple times that of the heating steam. The pretreated seawater is heated from normal temperature to 35°C through the flue gas cooler 13, further utilizing the waste heat of the flue gas. The rated amount of low-pressure steam entering the seawater desalination unit is ~5.5t/h. The water production ratio of seawater desalination is 9, and the freshwater production capacity of the seawater desalination device is 49.5t/h, that is, the daily freshwater production can reach 1188t. The low-temperature multiple-effect distillation method consumes less power, and the power consumption of seawater desalination is ~90kW/h. The fresh water produced by the low-temperature multi-effect distillation seawater desalination device 3 is deoxygenated distilled water, part of which is directly used as replenishment water for the heating furnace vaporization cooling system 1, and the rest is sent to other users.

Corresponding to the above example, the rated output power of the present invention is ~270kW, the rated fresh water production capacity is 49.5t/h, and the flue gas emission from the heating furnace complies with the emission standard of air pollutants in the steel rolling industry (GB 28665-2012).

The invention realizes the joint production of heat, electricity and water in the metallurgical heating furnace, and has remarkable social and economic benefits. Since the power consumption of low-temperature multi-effect distillation seawater desalination is low, the electric energy generated by the screw expander generator set can far meet the power consumption of low-temperature multi-effect seawater desalination. In addition, the fresh water produced by the low-temperature multi-effect distillation method has high purity and is suitable for direct use as makeup water for steam drums and boilers, or for other users.

The present invention has been further described above with the help of specific embodiments, but it should be understood that the specific description herein should not be construed as limiting the spirit and scope of the present invention. Various modifications made in the embodiments all belong to the protection scope of the present invention.

Claims (10)

1. a heating furnace waste heat comprehensive utilization system, it is characterised in that including:

Steam superheater, is arranged in furnace flue, and the low-pressure saturated steam that heating furnace evaporated cooling system produces flows into and steams Vapour superheater, low-pressure saturated steam can be heated by flue gas of heating furnace, to produce superheated steam；

Generating set, is in fluid communication with steam superheater, and the superheated steam produced in steam superheater flows into generating set, to enter Row generating；

Sea water desalinating unit, is in fluid communication with generating set, and the steam that generating set is discharged flows into sea water desalinating unit, to carry out Desalinization.

Heating furnace waste heat comprehensive utilization system the most according to claim 1, it is characterised in that also include: gas cooler, Being arranged in furnace flue, pre-treating seawater flows into gas cooler, and pre-treating seawater can be heated by flue gas of heating furnace, The pre-treating seawater that temperature raises flows into sea water desalinating unit.

Heating furnace waste heat comprehensive utilization system the most according to claim 1, it is characterised in that also include:

Cleaner unit, flue gas of heating furnace flows into cleaner unit, to carry out dedusting；

Desulfurizing tower, internal spray system is in fluid communication with sea water desalinating unit, the strong brine stream produced in sea water desalinating unit Entering spray system, the flue gas after dedusting flows into desulfurizing tower, and strong brine carries out washing desulphurization to flue gas.

4. according to described heating furnace waste heat comprehensive utilization system arbitrary in claims 1 to 3, it is characterised in that generating set For screw expander generating set.

Heating furnace waste heat comprehensive utilization system the most according to claim 4, it is characterised in that sea water desalinating unit is low temperature Effect distillation seawater desalinating device of multi.

Heating furnace waste heat comprehensive utilization system the most according to claim 5, it is characterised in that the steam of steam superheater goes out Mouth is connected by jet chimney with the steam inlet of screw expander generating set, jet chimney has been sequentially arranged valve, has dredged Hydrophone, temperature-detecting device, pressure-detecting device, flow detector.

Heating furnace waste heat comprehensive utilization system the most according to claim 5, it is characterised in that screw expander generating set Steam (vapor) outlet be connected by jet chimney, with the steam inlet of low temperature multiple-effect distillation sea water desalting device on jet chimney sequentially It is provided with pressure-detecting device, steam temperature reducing and pressure reducing device, bleeding device, valve, steam trap, temperature-detecting device, pressure detecting Device, flow detector.

8. a heating furnace residual heat integrative Application way, it is characterised in that comprise the following steps:

The low-pressure saturated steam that flue gas of heating furnace and heating furnace evaporated cooling system produce is carried out heat exchange, flue gas of heating furnace temperature Degree reduces, and low-pressure saturated steam becomes superheated steam；

The superheated steam of generation is transported to screw expander generating set, generates electricity；

The steam that screw expander generating set is discharged is transported to low temperature multiple-effect distillation sea water desalting device, carries out sea water light Change.

Heating furnace residual heat integrative Application way the most according to claim 8, it is characterised in that further comprising the steps of:

Utilize the flue gas of heating furnace after carrying out heat exchange with low-pressure saturated steam that pre-treating seawater is heated；

The pre-treating seawater that temperature raises is transported to low temperature multiple-effect distillation sea water desalting device, carries out desalinization.

Heating furnace residual heat integrative Application way the most according to claim 8 or claim 9, it is characterised in that also include following step Rapid:

Discharge after flue gas of heating furnace is carried out dedusting, desulfurization；

In sweetening process, use the strong brine produced in desalting process that flue gas of heating furnace is carried out washing desulphurization.