阅读说明：本技术 一种四段式蒸汽空气预热器疏水系统 (Four-section type steam air preheater drainage system ) 是由 龙吉生 谢军 瞿兆舟 张利军 周升 严浩文 黄兵 郑江龙 陈枫 吴义连 于 2019-03-30 设计创作，主要内容包括：本发明涉及城市生活垃圾焚烧领域,具体为加热垃圾焚烧炉燃烧空气的四段式蒸汽空气预热器疏水系统。四段式蒸汽空气预热器按空气流向依次布置低压过冷段换热器(4)、高压过冷段换热器(3)、低压冷凝段换热器(2)和高压冷凝段换热器(1)；汽包抽汽进入高压冷凝段换热器(1)换热后,再进入高压过冷段换热器(3),最后进入疏水管路；汽轮机抽汽经低压冷凝段换热器(2)换热后,再进入低压过冷段换热器(4),最后进入疏水管路；疏水调节阀采用缓冲罐液位信号调节疏水流量,确保换热能力和抽汽热量利用率,并能长期安全、稳定运行。(The invention relates to the field of municipal solid waste incineration, in particular to a four-section steam air preheater drainage system for heating combustion air of a waste incinerator. The four-section steam air preheater is sequentially provided with a low-pressure supercooling section heat exchanger (4), a high-pressure supercooling section heat exchanger (3), a low-pressure condensing section heat exchanger (2) and a high-pressure condensing section heat exchanger (1) according to the air flow direction; the steam drum extracts steam, enters a high-pressure condensing section heat exchanger (1) for heat exchange, then enters a high-pressure supercooling section heat exchanger (3) and finally enters a drain pipeline; the extracted steam of the steam turbine enters a low-pressure supercooling section heat exchanger (4) after being subjected to heat exchange by a low-pressure condensing section heat exchanger (2) and finally enters a drain pipeline; the drain regulating valve adopts a buffer tank liquid level signal to regulate drain flow, ensures the heat exchange capacity and the steam extraction heat utilization rate, and can operate safely and stably for a long time.)

1. A four-section steam air preheater drainage system is characterized in that a low-pressure supercooling section heat exchanger (4), a high-pressure supercooling section heat exchanger (3), a low-pressure condensing section heat exchanger (2) and a high-pressure condensing section heat exchanger (1) are sequentially arranged in the four-section steam air preheater according to the air flow direction; the steam drum extracts steam, enters a high-pressure condensing section heat exchanger (1) for heat exchange, then enters a high-pressure supercooling section heat exchanger (3) and finally enters a drain pipeline; the extracted steam of the steam turbine enters a low-pressure supercooling section heat exchanger (4) after being subjected to heat exchange by a low-pressure condensing section heat exchanger (2) and finally enters a drain pipeline;

The high-pressure steam extraction pipeline is provided with a regulating valve (5) which is connected with an inlet header of the high-pressure condensation section heat exchanger (1), an outlet header of the high-pressure steam extraction pipeline is connected with a buffer tank 1(6) through a pipeline, the buffer tank 1 is connected with an inlet header of the high-pressure supercooling section heat exchanger (3), and the outlet header of the high-pressure steam extraction pipeline is sequentially connected with a drain regulating valve 1(8) and a throttling orifice plate 1(9) through pipelines; the opening degree of the drainage regulating valve (8) is regulated according to a liquid level signal of a liquid level meter (7) of the buffer tank;

An adjusting valve (11) arranged on a low-pressure steam extraction pipeline is connected with an inlet header of a low-pressure section heat exchanger (2), an outlet header of the low-pressure steam extraction pipeline is connected with a buffer tank 2(12) through a pipeline, the buffer tank 2 is connected with an inlet header of a low-pressure supercooling section heat exchanger (4) through a pipeline, and the outlet header of the low-pressure steam extraction pipeline is sequentially connected with a drain adjusting valve 2(14) and a throttling orifice plate 2(15) through pipelines; the hydrophobic control valve 2(14) adjusts the opening degree according to a liquid level signal of a liquid level meter (13) of the buffer tank 2.

2. The four-stage steam air preheater drainage system of claim 1, comprising an extraction steam regulating valve, a buffer tank, a liquid level meter, a drainage regulating valve and a throttle orifice.

3. The four-stage steam air preheater drainage system of claim 1, wherein: the drainage system adopts an adjusting valve to adjust drainage flow according to the liquid level signal of the buffer tank.

4. The four-stage steam air preheater drainage system of claim 1, wherein: the drainage system stably maintains the pressure in the heat exchanger tube, and ensures that the heating capacity of the preheater and the utilization rate of the extraction heat reach design values.

5. The four-stage steam air preheater drainage system of claim 1, wherein: the drainage system is provided with a buffer tank, so that only condensed water enters the high-pressure supercooling section heat exchanger, and the vibration of the heat exchanger is reduced.

6. The four-stage steam air preheater drainage system of claim 1, wherein: the buffer tank and the allowable liquid level change range are arranged to avoid the opening degree of the drainage regulating valve from being frequently adjusted.

7. The four-stage steam air preheater drainage system of claim 1, wherein: and a throttle orifice is arranged at the downstream of the hydrophobic regulating valve to enlarge the flow regulating range of the hydrophobic regulating valve.

Technical Field

The invention relates to the field of municipal solid waste incineration, in particular to a four-section steam air preheater drainage system for heating combustion air of a waste incinerator.

Background

At present, primary air of a waste incineration plant is heated by a steam air preheater, and the four-section type steam air preheater is applied more and more for improving the utilization rate of steam extraction heat and solving the problems of pipeline vibration, deaerator boiling and the like. The four-section steam air preheater is additionally provided with a low-pressure supercooling section heat exchanger and a high-pressure supercooling section heat exchanger, and the saturated water from the high-pressure condensing section heat exchanger and the low-pressure condensing section heat exchanger is further cooled to 90-120 ℃. The heat exchange capacity and the steam extraction heat utilization rate of the four-section steam air preheater are mostly determined by the reliability and the rationality of a drainage system, and the conventional inverted bucket drain valve and the gas-liquid two-phase flow drain valve have the problems of drainage and steam entrainment in different degrees, incapability of stably maintaining the pressure in a heat exchanger tube, easiness in damage and the like. Problems with the steam trap system can also lead to a series of problems with the steam air preheater not being able to heat the air to the design temperature, the extraction flow being higher than the design value, and the deaerator boiling.

The invention relates to a four-section steam air preheater drainage system, wherein the drainage of a high-pressure section and a low-pressure section adopts regulating valves, and the drainage flow is regulated according to the liquid level of a buffer tank, so that the heat exchange capacity and the steam extraction heat utilization rate are ensured, and the four-section steam air preheater drainage system can be safely and stably operated for a long time.

Disclosure of Invention

The invention provides a four-section steam air preheater drainage system, wherein a low-pressure supercooling section heat exchanger (4), a high-pressure supercooling section heat exchanger (3), a low-pressure condensing section heat exchanger (2) and a high-pressure condensing section heat exchanger (1) are sequentially arranged in the four-section steam air preheater according to the air flow direction; the extracted steam of the steam drum enters a high-pressure condensing section heat exchanger (1) for heat exchange, then enters a high-pressure supercooling section heat exchanger (3) and finally enters a drain pipeline. The extracted steam of the steam turbine enters the low-pressure supercooling section heat exchanger (4) after being subjected to heat exchange by the low-pressure condensing section heat exchanger (2) and finally enters a drain pipeline.

The high-pressure steam extraction pipeline is provided with a regulating valve (5) which is connected with an inlet header of the high-pressure condensation section heat exchanger (1), an outlet header of the high-pressure steam extraction pipeline is connected with a buffer tank 1(6) through a pipeline, the buffer tank 1 is connected with an inlet header of the high-pressure supercooling section heat exchanger (3), and the outlet header of the high-pressure steam extraction pipeline is sequentially connected with a drain regulating valve 1(8) and a throttling orifice plate 1(9) through pipelines. The opening degree of the drainage regulating valve (8) is regulated according to a liquid level signal of a liquid level meter (7) of the buffer tank.

The regulating valve (11) arranged on the low-pressure steam extraction pipeline is connected with the inlet header of the low-pressure section heat exchanger (2), the outlet header of the low-pressure steam extraction pipeline is connected with the buffer tank 2(12) through a pipeline, the buffer tank 2 is connected with the inlet header of the low-pressure supercooling section heat exchanger (4), and the outlet header of the low-pressure steam extraction pipeline is sequentially connected with the drain regulating valve 2(14) and the orifice plate 2(15) through pipelines. The hydrophobic control valve 2(14) adjusts the opening degree according to a liquid level signal of a liquid level meter (13) of the buffer tank 2.

further, the device comprises a steam extraction regulating valve, a buffer tank, a liquid level meter, a drainage regulating valve and a throttle orifice.

During operation, the high-pressure steam extraction regulating valve adjusts the steam flow entering the high-pressure condensation section heat exchanger according to the hot air temperature at the outlet of the preheater, the steam-water mixture after heat exchange condensation enters the buffer tank, the water in the buffer tank enters the high-pressure supercooling section heat exchanger through the pipeline and is further cooled to 90-120 ℃ and enters the drain pipeline through the drain regulating valve, and the drain quantity is adjusted by the drain regulating valve according to the liquid level of the buffer tank. Similarly, the low-pressure steam extraction regulating valve regulates the steam flow entering the low-pressure condensation section heat exchanger according to the temperature of hot air at the outlet of the preheater, the steam-water mixture after heat exchange condensation enters the buffer tank, water in the buffer tank enters the low-pressure supercooling section heat exchanger through a pipeline and is further cooled to 90-120 ℃ and enters a drain pipeline through the drain regulating valve, and the drain quantity is regulated by the drain regulating valve according to the liquid level of the buffer tank. As the load of the steam air preheater is greatly changed in the front and the back of the operation and in different seasons, the throttling orifice plate is arranged at the rear end of the drain control valve so as to increase the flow regulating range of the drain control valve.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a steam air preheater flow diagram.

FIG. 2 is a diagram of a steam air preheater drainage system.

In the figure 1, 1 is a high-pressure condensing section heat exchanger, 2 is a low-pressure condensing section heat exchanger, 3 is a high-pressure supercooling section heat exchanger, and 4 is a low-pressure supercooling section heat exchanger.

In the figure 2, 1 is a high-pressure condensation section heat exchanger, 2 is a low-pressure condensation section heat exchanger, 3 is a high-pressure supercooling section heat exchanger, 4 is a low-pressure supercooling section heat exchanger, 5 is a high-pressure steam extraction regulating valve, 6 is a buffer tank 1, 7 is a liquid level meter 1, 8 is a drain regulating valve 1, 9 is a throttle orifice plate 1, 10 is an outlet air temperature measuring point 1, 11 is a low-pressure steam extraction regulating valve, 12 is a buffer tank 2, 13 is a liquid level meter 2, 14 is a drain regulating valve 2, 15 is a throttle orifice plate 2, 16 is an outlet air temperature measuring point 2.

Detailed Description

in fig. 1, a four-section steam air preheater is sequentially provided with a low-pressure supercooling section heat exchanger (4), a high-pressure supercooling section heat exchanger (3), a low-pressure condensing section heat exchanger (2) and a high-pressure condensing section heat exchanger (1) according to the air flow direction. The extracted steam of the steam drum enters a high-pressure condensing section heat exchanger (1) for heat exchange, then enters a high-pressure supercooling section heat exchanger (3) and finally enters a drain pipeline. The extracted steam of the steam turbine enters the low-pressure supercooling section heat exchanger (4) after being subjected to heat exchange by the low-pressure condensing section heat exchanger (2) and finally enters a drain pipeline.

In a figure 2, a high-pressure steam extraction regulating valve (5) feeds back a temperature signal through an outlet air temperature measuring point 1(10) to regulate the flow of steam entering a high-pressure condensing section heat exchanger (1), a steam-water mixture after heat exchange and condensation enters a buffer tank 1(6), water in the buffer tank 1(6) enters a high-pressure supercooling section heat exchanger (3) through a pipeline to be further cooled to 90-120 ℃, and finally enters a drain pipeline through a drain regulating valve 1 (8). The opening degree of the hydrophobic regulating valve 1(8) is regulated according to the feedback signals of the liquid level meter 1(7), the opening degree of the regulating valve is reduced when the liquid level is lowered, and the opening degree of the regulating valve is increased when the liquid level is raised. The buffer tank and the allowable liquid level change range are arranged to avoid the opening degree of the drainage regulating valve from being frequently adjusted. Similarly, the low-pressure steam extraction regulating valve (11) feeds back a temperature signal through an outlet air temperature measuring point 2(16) to regulate the steam flow entering the low-pressure condensing section heat exchanger (2), the steam-water mixture after heat exchange and condensation enters a buffer tank 2(12), the water in the buffer tank 2(12) enters the low-pressure supercooling section heat exchanger (4) through a pipeline to be further cooled to 90-120 ℃, and finally enters a drain pipeline through a drain regulating valve 2 (14). The hydrophobic regulating valve 2(14) regulates the opening according to the feedback signals of the liquid level meter 2(13), reduces the opening of the regulating valve when the liquid level is lowered, and increases the opening of the regulating valve when the liquid level is raised. As the load of the steam air preheater is greatly changed in the front and the rear periods of operation and different seasons, the throttle valve group is arranged at the rear end of the drain control valve so as to increase the flow regulating range of the drain control valve.