阅读说明：本技术 一种工业余热回收高效发电方法及其系统 (Industrial waste heat recovery efficient power generation method and system ) 是由 侯宾才 刘亚雷 陈慧 管晓东 于 2021-04-02 设计创作，主要内容包括：本发明公开了一种工业余热回收高效发电方法及其系统,属于工业余热回收利用技术领域。本发明采用再热技术,将低压蒸汽送至余热锅炉再热器再热提高温度,然后将再热蒸汽送入汽轮机低压缸继续膨胀做功变为乏汽。与现有技术相比,本发明汽轮机低压缸内效率提高,可提高发电量,系统发电效率可进一步提高6～10%左右；同时,因再热蒸汽过热度提高,汽轮机低压缸排汽干度高,汽轮机末级叶片腐蚀风险降低,也提高了汽轮机的安全性。因此,本发明无论是在效率上还是在安全性上都相对于现有技术具有明显的进步。(The invention discloses an industrial waste heat recovery high-efficiency power generation method and a system thereof, belonging to the technical field of industrial waste heat recovery and utilization. The invention adopts a reheating technology, low-pressure steam is sent to a reheater of a waste heat boiler to be reheated and the temperature is raised, and then the reheated steam is sent to a low-pressure cylinder of a steam turbine to be continuously expanded and work is changed into dead steam. Compared with the prior art, the efficiency in the low-pressure cylinder of the steam turbine is improved, the generated energy can be improved, and the generating efficiency of the system can be further improved by about 6-10%; meanwhile, because the superheat degree of the reheated steam is improved, the dryness of the discharged steam of the low-pressure cylinder of the steam turbine is high, the corrosion risk of the last-stage blade of the steam turbine is reduced, and the safety of the steam turbine is also improved. Thus, the present invention represents a significant advance over the prior art, both in efficiency and safety.)

1. An industrial waste heat recovery high-efficiency power generation method is characterized in that a high-pressure superheater, a low-pressure reheater, evaporation equipment and an economizer are heated through waste heat, and a steam turbine drives a generator to generate power, and the method comprises the following steps:

high-pressure superheated steam generated by heating the high-pressure superheater is input into a high-pressure cylinder of a steam turbine through a steam pipeline to be expanded and do work, and then is changed into low-pressure steam;

sending the low-pressure steam to a low-pressure reheater for reheating and increasing the temperature, and then sending the reheated steam to a low-pressure cylinder of a steam turbine for continuously expanding and applying work to change the reheated steam into dead steam;

the exhaust steam discharged by the low-pressure cylinder is discharged into a condenser to be subjected to heat release and condensation to form water, and the water is sequentially sent into an economizer and evaporation equipment by a water feeding pump to be heated and then converted into saturated steam;

the saturated steam enters a high-pressure superheater to be heated to generate high-pressure superheated steam, and then the process is repeated.

2. The industrial waste heat recovery high efficiency power generation method of claim 1, characterized in that: after exhausted steam discharged by the low-pressure cylinder is discharged into a condenser for heat release and condensation to form water, preheating and deoxidization are firstly carried out, and then the water is sent into the economizer by a water feeding pump.

3. The industrial waste heat recovery high efficiency power generation method of claim 1, characterized in that: and the circulating cooling water pump pumps cooling water into the condenser through the cooling water pipe for absorption, and then the cooling water is discharged through the cooling water pipe for cooling to obtain the cooling water for recycling.

4. The industrial waste heat recovery high efficiency power generation method of claim 1, characterized in that: the evaporation device is an evaporator or a membrane wall.

5. The industrial waste heat recovery high-efficiency power generation method according to any one of claims 1 to 4, characterized in that: and the high-pressure cylinder and the low-pressure cylinder of the steam turbine are coaxially connected.

6. The industrial waste heat recovery high-efficiency power generation method according to any one of claims 1 to 4, characterized in that: the high-pressure cylinder and the low-pressure cylinder of the steam turbine are the same cylinder body and are separated by a middle partition plate.

7. The industrial waste heat recovery high-efficiency power generation method according to any one of claims 1 to 4, characterized in that: the humidity of the exhaust steam after the low-pressure cylinder of the steam turbine does work is not more than 6%.

8. An industrial waste heat recovery high-efficiency power generation system comprises a steam turbine (1), a power generator (2), a condenser (3) and a water feeding pump (9), wherein the steam turbine (1) drives the power generator (2) to generate power, and is characterized by further comprising a high-pressure superheater (14), a low-pressure reheater (13), evaporation equipment and an economizer (10), wherein the high-pressure superheater (14), the low-pressure reheater (13) and the economizer (10) are heated through waste heat;

an outlet of the high-pressure superheater (14) is connected with an air inlet of a high-pressure cylinder of the steam turbine (1), an exhaust port of the high-pressure cylinder is connected with an inlet of a low-pressure reheater (13), and an outlet of the low-pressure reheater (13) is connected with an air inlet of a low-pressure cylinder of the steam turbine (1);

the steam turbine (1) low-pressure cylinder gas outlet is connected with the condenser (3), the outlet water of the condenser (3) is connected with the inlet of the economizer (10) through the outlet of the feed pump (9), and the water preheated by the economizer (10) enters the evaporation equipment to be converted into saturated steam to enter the high-pressure superheater (14).

9. The industrial heat recovery high efficiency power generation system of claim 8, wherein: the evaporation device is an evaporator or a membrane wall.

Technical Field

The invention belongs to the technical field of industrial waste heat recovery and utilization, and particularly relates to an industrial waste heat recovery efficient power generation method and system.

Background

The industrial waste heat resource is used as an energy form which is frequently appeared in industry, and the recycling of the industrial waste heat resource is an important means for responding to the national environmental protection policy and realizing energy conservation and emission reduction. In general, in waste heat utilization, the biggest problems for the steam turbine set are: the temperature of main steam is low, the superheat degree is not high, the exhaust steam humidity is difficult to control, and the safety of a steam turbine is difficult to guarantee.

Reheating refers to introducing the exhaust steam after acting in the high-pressure stage of the steam turbine into a boiler reheater to absorb heat again, raising the steam temperature, and introducing the high-temperature steam into the low-pressure stage of the steam turbine to continue acting. The reheating technology is an effective means for improving the steam cycle efficiency, large thermal power stations all adopt the reheating technology, and partial thermal power stations even adopt the secondary reheating technology. With the development of steam turbine technology and the continuous pursuit of economic efficiency of steam turbines by various parties, in recent years, more and more units below 100MW also start to adopt reheating technology.

Therefore, it is necessary to develop a high-efficiency reheat type waste heat recovery power generation method suitable for the field of industrial waste heat recovery to realize maximum utilization of waste heat resources.

Disclosure of Invention

The invention aims to solve the problem that the exhaust steam humidity is difficult to control in the existing waste heat utilization technology, and provides a reheating type waste heat recovery power generation method and a system thereof.

Specifically, the invention specifically adopts the following technical scheme that an industrial waste heat recovery high-efficiency power generation method heats a high-pressure superheater, a low-pressure reheater, evaporation equipment and an economizer through waste heat, and drives a generator to generate power through a steam turbine, and the method comprises the following steps: high-pressure superheated steam generated by heating the high-pressure superheater is input into a high-pressure cylinder of a steam turbine through a steam pipeline to be expanded and do work, and then is changed into low-pressure steam; sending the low-pressure steam to a low-pressure reheater for reheating and increasing the temperature, and then sending the reheated steam to a low-pressure cylinder of a steam turbine for continuously expanding and applying work to change the reheated steam into dead steam; the exhaust steam discharged by the low-pressure cylinder is discharged into a condenser to be subjected to heat release and condensation to form water, and the water is sequentially sent into an economizer and evaporation equipment by a water feeding pump to be heated and then converted into saturated steam; the saturated steam enters a high-pressure superheater to be heated to generate high-pressure superheated steam, and then the process is repeated.

The technical scheme is further characterized in that: after exhausted steam discharged by the low-pressure cylinder is discharged into a condenser for heat release and condensation to form water, preheating and deoxidization are firstly carried out, and then the water is sent into the economizer by a water feeding pump.

The technical scheme is further characterized in that: and the circulating cooling water pump pumps cooling water into the condenser through the cooling water pipe for absorption, and then the cooling water is discharged through the cooling water pipe for cooling to obtain the cooling water for recycling.

The technical scheme is further characterized in that: the evaporation device is an evaporator or a membrane wall.

The technical scheme is further characterized in that: and the high-pressure cylinder and the low-pressure cylinder of the steam turbine are coaxially connected.

The technical scheme is further characterized in that: the high-pressure cylinder and the low-pressure cylinder of the steam turbine are the same cylinder body and are separated by a middle partition plate.

The technical scheme is further characterized in that: the humidity of the exhaust steam after the low-pressure cylinder of the steam turbine does work is not more than 6%.

The invention also discloses a waste heat recovery power generation system, which comprises a steam turbine 1, a generator 2, a condenser 3 and a water feeding pump 9, wherein the steam turbine 1 drives the generator 2 to generate power, and the waste heat recovery power generation system also comprises a high-pressure superheater 14, a low-pressure reheater 13, evaporation equipment and an economizer 10, wherein the high-pressure superheater 14, the low-pressure reheater 13, the evaporator 12 and the economizer 10 are heated by waste heat; an outlet of the high-pressure superheater 14 is connected with an air inlet of a high-pressure cylinder of the steam turbine 1, an exhaust port of the high-pressure cylinder is connected with an inlet of a low-pressure reheater 13, and an outlet of the low-pressure reheater 13 is connected with an air inlet of a low-pressure cylinder of the steam turbine 1; the gas outlet of the low-pressure cylinder of the steam turbine 1 is connected with the condenser 3, the outlet water of the condenser 3 is connected with the inlet of the economizer 10 through the outlet of the water feed pump 9, and the water heated by the economizer 10 and the evaporation equipment is converted into saturated steam to enter the high-pressure superheater 14.

The technical scheme is further characterized in that: the evaporation device is an evaporator or a membrane wall.

The invention has the following beneficial effects: by adopting a reheating technology, the efficiency in a low-pressure cylinder of the steam turbine is improved, the generated energy can be improved, and the generating efficiency of a system can be further improved by about 6-10%; meanwhile, because the superheat degree of the reheated steam is improved, the dryness of the discharged steam of the low-pressure cylinder of the steam turbine is high, the corrosion risk of the last-stage blade of the steam turbine is reduced, and the safety of the steam turbine is also improved. Thus, the present invention represents a significant advance over the prior art, both in efficiency and safety.

Drawings

FIG. 1 is a flow chart of a waste heat recovery high efficiency power generation system of embodiment 1;

FIG. 2 is a flow chart of a waste heat recovery high efficiency power generation system of embodiment 2;

in the above figures, 1-steam turbine; 1 a-high pressure cylinder exhaust; 1 b-low pressure cylinder inlet; 2-a generator; 3-a condenser; 4-circulating cooling water pump; 5-a cooling tower; 6-a condensate pump; 7-a shaft seal heater; 8-a deaerator; 9-a water supply pump; 10-a coal economizer; 11-steam drum; 12-an evaporator; 13-low pressure reheater; 14-a high pressure superheater; 15-a waste heat boiler; 16-a membrane wall; 17-garbage incinerator.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Example 1:

fig. 1 is an embodiment of the present invention for recycling waste heat of a glass kiln, and a system thereof mainly includes a steam turbine 1, a generator 2, a condenser 3, a circulating cooling water pump 4, a cooling tower 5, a condensate pump 6, a shaft seal heater 7, a deaerator 8, a feed pump 9, a waste heat boiler 15, etc., and the main working processes thereof are as follows:

(1) the glass kiln flue gas enters a waste heat boiler 15, sequentially passes through a high-pressure superheater 14, a low-pressure reheater 13, an evaporator 12 and an economizer 10 in the waste heat boiler 15 and heats working media in the waste heat boiler; the steam turbine 1 drives the generator 2 to generate electricity;

(2) cold water from a water supply pump 9 enters an economizer 10 to be preheated and then is input into a steam drum 11, then the cold water enters an evaporator 12 through a downcomer, the water is heated into saturated steam in the evaporator, and then the saturated steam enters the steam drum 11 through an ascending pipe;

(3) saturated steam enters the high-pressure superheater 14 to be heated after being output from the steam drum 11 to generate high-pressure superheated steam;

(4) the high-pressure superheated steam is input into a high-pressure cylinder of the steam turbine 1 through a steam pipeline and is changed into low-pressure steam after expansion and work;

(5) outputting low-pressure steam from a high-pressure cylinder exhaust port 1a, sending the low-pressure steam to a low-pressure reheater 13 for reheating to increase the temperature, sending the reheated steam to a low-pressure cylinder of the steam turbine 1 through a low-pressure cylinder air inlet 1b, and continuously expanding to apply work to change the reheated steam into dead steam;

(6) exhausting the exhaust steam exhausted from the low-pressure cylinder of the steam turbine 1 into a condenser 3 to release heat and condense the exhaust steam into water; the circulating cooling water pump 4 pumps cooling water in a water pool of the cooling tower 5 into the condenser 3 through a cooling water pipe for absorption, then the cooling water is discharged to the cooling tower 5 through the cooling water pipe for cooling, and finally the cooled water returns to the water pool for recycling;

(7) the water in the condenser 3 is preheated by a shaft seal heater 7 through a condensate pump 6, then enters a deaerator 8 for deaerating, is sent to an economizer 10 for preheating through a water feeding pump 9, and then the process is repeated.

In this embodiment, the high pressure cylinder and the low pressure cylinder of the steam turbine may be coaxially connected, or may be the same cylinder body, separated by a middle partition plate. Because the superheat degree of the reheated steam is improved, the humidity of the exhaust steam after the low-pressure cylinder of the steam turbine does work is not more than 6%, the corrosion risk of the last-stage blade of the steam turbine is reduced, and the safety of the steam turbine is obviously improved. The efficiency of the steam turbine 1 in the low-pressure cylinder is improved, and the power generation amount of the generator 2 can be further improved.

Example 2:

fig. 2 is an implementation manner of the waste heat recovery and utilization in waste incineration according to the present invention, similar to the embodiment 1, the system mainly includes a steam turbine 1, a generator 2, a condenser 3, a circulating cooling water pump 4, a cooling tower 5, a condensate pump 6, a shaft seal heater 7, a deaerator 8, a feed pump 9, a waste incinerator 17, and the like, and the main working process is as follows:

(1) the garbage is incinerated in the garbage incinerator 17 to generate high-temperature flue gas, and the high-temperature flue gas passes through the membrane wall 16, the low-pressure reheater 13, the high-pressure superheater 14 and the economizer 10 in sequence and heats working media in the high-temperature flue gas; the steam turbine 1 drives the generator 2 to generate electricity;

(2) cold water from a water supply pump 9 enters an economizer 10 to be preheated and then is input into a steam drum 11, then enters a membrane wall 16 through a downcomer, the water is heated into saturated steam in the membrane wall 16, and then enters the steam drum 11 through an ascending pipe;

(3) saturated steam enters the high-pressure superheater 14 to be heated after being output from the steam drum 11 to generate high-pressure superheated steam;

(4) the high-pressure superheated steam is input into a high-pressure cylinder of the steam turbine 1 through a steam pipeline and is changed into low-pressure steam after expansion and work;

(5) outputting low-pressure steam from a high-pressure cylinder exhaust port 1a, sending the low-pressure steam to a low-pressure reheater 13 for reheating to increase the temperature, sending the reheated steam to a low-pressure cylinder of the steam turbine 1 through a low-pressure cylinder air inlet 1b, and continuously expanding to apply work to change the reheated steam into dead steam;

(6) exhausting the exhaust steam exhausted from the low-pressure cylinder of the steam turbine 1 into a condenser 3 to release heat and condense the exhaust steam into water; the circulating cooling water pump 4 pumps cooling water in a water pool of the cooling tower 5 into the condenser 3 through a cooling water pipe for absorption, then the cooling water is discharged to the cooling tower 5 through the cooling water pipe for cooling, and finally the cooled water returns to the water pool for recycling;

(7) the water in the condenser 3 is preheated by a shaft seal heater 7 through a condensate pump 6, then enters a deaerator 8 for deaerating, is sent to an economizer 10 for preheating through a water feeding pump 9, and then the process is repeated.

Although the present invention has been described in terms of the preferred embodiment, it is not intended that the invention be limited to the embodiment. Any equivalent changes or modifications made without departing from the spirit and scope of the present invention also belong to the protection scope of the present invention. The scope of the invention should therefore be determined with reference to the appended claims.