阅读说明：本技术 一种背压供热机组中余压余热的回收系统及回收方法 (Recovery system and recovery method for residual pressure waste heat in back pressure heat supply unit ) 是由 毛刚 金宇航 朱佳斌 周姣 梁小丽 吴俊芬 徐雪莹 王纯 夏积恩 戴佳栩 寿恩广 于 2020-05-15 设计创作，主要内容包括：本发明提供一种背压供热机组中余压余热的回收系统及回收方法,可以减少水、热量和压力能的损耗,增加背压供热机组的供热量,消除“冒白烟”的现象。本发明包括背压式汽轮机、除氧器、疏水箱、疏水扩容器、定期排污扩容器、一至七号阀门、蒸汽喷射泵、主管路和旁路管路。正常运行时,关闭三号阀门和四号阀门,打开其余阀门；背压式汽轮机的排汽送入蒸汽喷射泵作为工作蒸汽,使蒸汽喷射泵抽取定期排污扩容器、疏水扩容器、疏水箱的排汽后,压力降低为可以被除氧器利用的中压蒸汽,中压蒸汽进入除氧器；如果蒸汽喷射泵出现故障,打开旁路三号阀门和四号阀门,关闭一号阀门和二号阀门,系统可继续工作,保证系统持续运行。(The invention provides a recovery system and a recovery method of residual pressure and waste heat in a backpressure heat supply unit, which can reduce the loss of water, heat and pressure energy, increase the heat supply amount of the backpressure heat supply unit and eliminate the phenomenon of white smoke emission. The steam turbine comprises a back pressure steam turbine, a deaerator, a drain tank, a drain flash tank, a periodical pollution discharge flash tank, a first valve, a second valve, a third valve, a fourth valve, a seventh valve, a steam jet pump, a main pipeline and a bypass pipeline. When the valve operates normally, the third valve and the fourth valve are closed, and the rest valves are opened; the exhaust steam of the back pressure steam turbine is sent to a steam jet pump as working steam, so that after the steam jet pump extracts the exhaust steam of the periodic blowdown flash tank, the drainage flash tank and the drainage box, the pressure is reduced to medium-pressure steam which can be utilized by a deaerator, and the medium-pressure steam enters the deaerator; if the steam jet pump breaks down, the third valve and the fourth valve of the bypass are opened, the first valve and the second valve are closed, and the system can continue to work, so that the continuous operation of the system is ensured.)

1. A recovery system of residual pressure waste heat in a backpressure heat supply unit comprises a backpressure steam turbine, a deaerator, a drain tank, a drain flash tank and a periodic blowdown flash tank; the method is characterized in that: the steam injection device also comprises a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, a steam injection pump, a main pipeline and a bypass pipeline; the steam outlet of the back pressure turbine is connected with the deaerator through a main pipeline, and a first valve, a steam jet pump and a second valve are sequentially arranged on the main pipeline; the bypass pipeline is connected with the main pipeline in parallel, and a third valve and a fourth valve are sequentially arranged on the bypass pipeline; the steam extraction port of the steam jet pump is connected with the periodical pollution discharge flash tank through a pipeline, and a fifth valve is arranged on the pipeline; the steam extraction port of the steam jet pump is connected with the drainage flash tank through a pipeline, and a number six valve is arranged on the pipeline; the steam extraction port of the steam jet pump is connected with the drain tank through a pipeline, and a seventh valve is arranged on the pipeline.

2. The recovery system of residual pressure and waste heat in a back pressure heat supply unit according to claim 1, characterized in that: the system also comprises a heat device for the outer net, and the heat device for the outer net is connected with the steam outlet of the back pressure turbine.

3. The recovery system of residual pressure and waste heat in a back pressure heat supply unit according to claim 1, characterized in that: the three-way valve, the regulating valve and the four-way valve are sequentially arranged on the bypass pipeline.

4. The recovery system of residual pressure and waste heat in a back pressure heat supply unit according to claim 1, characterized in that: the first valve, the second valve, the third valve and the fourth valve are all manual gate valves, and the fifth valve, the sixth valve and the seventh valve are all electric gate valves.

5. A recovery method of residual pressure and waste heat in a backpressure heat supply unit is characterized by comprising the following steps: the method is carried out by adopting the recovery system of any one of claims 1 to 4, and comprises the following steps: when the valve operates normally, the third valve and the fourth valve are closed, the first valve and the second valve are opened, and the fifth valve, the sixth valve and the seventh valve are opened simultaneously; the exhaust steam of the back pressure steam turbine is sent to a steam jet pump as working steam, so that after the steam jet pump extracts the exhaust steam of the periodic blowdown flash tank, the drainage flash tank and the drainage box, the pressure is reduced to medium-pressure steam which can be utilized by a deaerator, and the medium-pressure steam enters the deaerator; if the steam jet pump breaks down during the operation, the third valve and the fourth valve of the bypass are opened, the first valve and the second valve are closed, and the system can continue to work, so that the continuous operation of the system is ensured.

Technical Field

The invention relates to a recovery system and a recovery method of residual pressure and waste heat in a backpressure heat supply unit.

Background

1. In traditional backpressure heat supply unit, the backpressure steam extraction pressure of external network heat supply often can not match with the heating steam pressure of oxygen-eliminating device, and in order to satisfy external network heat supply's requirement, the heat supply steam of oxygen-eliminating device often will be through throttle decompression, desuperheating, and this is because the waste of throttle decompression must just form the pressure energy.

2. In traditional backpressure heat supply unit, must set up dilatation devices such as periodic blowdown flash tank, hydrophobic flash tank, drain tank, the exhaust of these devices often leads to the atmosphere, often can form the phenomenon of "giving off white smoke", and this kind of phenomenon not only lets the visual effect who influences whole steam power plant easily, still can increase the loss of hot power system normal water and heat in the power plant.

Disclosure of Invention

The invention aims to overcome the defects in the prior art, and provides a system and a method for recovering residual pressure and waste heat in a backpressure heat supply unit, which have reasonable structural design, can reduce the loss of water, heat and pressure energy, increase the heat supply amount of the backpressure heat supply unit, and eliminate the phenomenon of white smoke emission.

The technical scheme adopted by the invention for solving the problems is as follows: a recovery system of residual pressure waste heat in a backpressure heat supply unit comprises a backpressure steam turbine, a deaerator, a drain tank, a drain flash tank and a periodic blowdown flash tank; the method is characterized in that: the steam injection device also comprises a first valve, a second valve, a third valve, a fourth valve, a fifth valve, a sixth valve, a seventh valve, a steam injection pump, a main pipeline and a bypass pipeline; the steam outlet of the back pressure turbine is connected with the deaerator through a main pipeline, and a first valve, a steam jet pump and a second valve are sequentially arranged on the main pipeline; the bypass pipeline is connected with the main pipeline in parallel, and a third valve and a fourth valve are sequentially arranged on the bypass pipeline; the steam extraction port of the steam jet pump is connected with the periodical pollution discharge flash tank through a pipeline, and a fifth valve is arranged on the pipeline; the steam extraction port of the steam jet pump is connected with the drainage flash tank through a pipeline, and a number six valve is arranged on the pipeline; the steam extraction port of the steam jet pump is connected with the drain tank through a pipeline, and a seventh valve is arranged on the pipeline.

The invention also comprises a heat device for the outer net, and the heat device for the outer net is connected with the steam outlet of the back pressure turbine.

The invention also comprises a regulating valve, wherein the third valve, the regulating valve and the fourth valve are sequentially arranged on the bypass pipeline.

The first valve, the second valve, the third valve and the fourth valve are all manual gate valves, and the fifth valve, the sixth valve and the seventh valve are all electric gate valves.

A recovery method of residual pressure and waste heat in a backpressure heat supply unit is characterized by comprising the following steps: the recycling system is adopted for carrying out the following steps: when the valve operates normally, the third valve and the fourth valve are closed, the first valve and the second valve are opened, and the fifth valve, the sixth valve and the seventh valve are opened simultaneously; the exhaust steam of the back pressure steam turbine is sent to a steam jet pump as working steam, so that after the steam jet pump extracts the exhaust steam of the periodic blowdown flash tank, the drainage flash tank and the drainage box, the pressure is reduced to medium-pressure steam which can be utilized by a deaerator, and the medium-pressure steam enters the deaerator; if the steam jet pump breaks down during the operation, the third valve and the fourth valve of the bypass are opened, the first valve and the second valve are closed, and the system can continue to work, so that the continuous operation of the system is ensured.

Compared with the prior art, the invention has the following advantages and effects:

1. the residual pressure loss caused by the throttling of the deoxygenated heating steam can be recovered, and the heat supply amount of the back pressure heat supply unit is increased.

2. The loss of water and heat in a thermodynamic system is reduced, the phenomenon of white smoke emission is eliminated, and the production environment of the thermal power plant can be beautified.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail below by way of examples with reference to the accompanying drawings, which are illustrative of the present invention and are not to be construed as limiting the present invention.

Referring to fig. 1, the invention comprises a first valve 1, a second valve 2, a third valve 3, a fourth valve 4, a fifth valve 5, a sixth valve 6, a seventh valve 7, a back pressure turbine 8, an external network heat device 9, a steam jet pump 10, a regulating valve 11, a deaerator 12, a drain tank 13, a drain flash tank 1, a periodic blowdown flash tank 15, a main pipeline 16 and a bypass pipeline 17.

The steam outlet of the back pressure turbine 8 is connected with a deaerator 12 through a main pipeline, and a first valve 1, a steam jet pump 10 and a second valve 2 are sequentially installed on the main pipeline 16. Wherein the steam jet pump 10 has an inlet and an outlet connected to the main pipeline 16.

The bypass pipeline 17 is connected with the main pipeline 16 in parallel, and the third valve 3, the regulating valve 11 and the fourth valve 4 are sequentially arranged on the bypass pipeline 17.

The steam extraction port of the steam jet pump 10 is connected with a periodic blowdown flash tank 15 through a pipeline, and a fifth valve 5 is installed on the pipeline. The steam extraction port of the steam jet pump 10 is connected with a drain flash tank 14 through a pipeline, and a number six valve 6 is installed on the pipeline. The steam extraction port of the steam jet pump 10 is connected with a drain tank 13 through a pipeline, and a seventh valve 7 is installed on the pipeline.

The first valve 1, the second valve 2, the third valve 3 and the fourth valve 4 are all manual gate valves, and the fifth valve 5, the sixth valve 6 and the seventh valve 7 are all electric gate valves.

The heat device 9 for the outer grid is connected to the exhaust port of the back pressure turbine 8.

A recovery method of residual pressure and waste heat in a backpressure heat supply unit is carried out by adopting the recovery system, and comprises the following steps:

and in normal operation, the third valve 3 and the fourth valve 4 are closed, the first valve 1 and the second valve 2 are opened, and the fifth valve 5, the sixth valve 6 and the seventh valve 7 are opened simultaneously. The exhaust steam of the back pressure turbine 8 is high pressure steam, and is sent to the steam jet pump 10 as working steam, so that after the steam jet pump 10 extracts the exhaust steam of the periodic blowdown flash tank 15, the drainage flash tank 14 and the drainage box 13, the pressure is reduced to medium pressure steam which can be utilized by the deaerator, and the medium pressure steam enters the deaerator 12. Therefore, working medium and heat of the exhausted steam of the periodic blowdown flash tank 15, the drainage flash tank 14 and the drainage tank 13 can be recovered, the consumption of high-pressure steam for deoxygenation and heating is reduced, and more heat can be supplied to an external network heat utilization device.

If the steam jet pump 10 breaks down during operation, the third valve 3 and the fourth valve 4 of the bypass are opened, and the first valve 1 and the second valve 2 are closed, so that the system can continue to work, and the thermodynamic system can be ensured to continuously operate.

In addition, it should be noted that the specific embodiments described in the present specification may be different in the components, the shapes of the components, the names of the components, and the like, and the above description is only an illustration of the structure of the present invention. Equivalent or simple changes in the structure, characteristics and principles of the invention are included in the protection scope of the patent. Various modifications, additions and substitutions for the specific embodiments described may be made by those skilled in the art without departing from the scope of the invention as defined in the accompanying claims.