CN114279252A - Steam-air preheater system - Google Patents
Steam-air preheater system Download PDFInfo
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- CN114279252A CN114279252A CN202111677512.8A CN202111677512A CN114279252A CN 114279252 A CN114279252 A CN 114279252A CN 202111677512 A CN202111677512 A CN 202111677512A CN 114279252 A CN114279252 A CN 114279252A
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Abstract
The invention discloses a steam-air preheater system, which comprises a preheater body, a steam-air preheater and a steam-air preheater, wherein the preheater body is provided with an air heating cavity, a cold air inlet and a hot air outlet; the steam condensation section heat exchanger is arranged in the air heating cavity and close to the hot air outlet, and an inlet of the steam condensation section heat exchanger is used for being connected with a steam pipeline; the water draining and supercooling section heat exchanger is arranged in the air heating cavity and is positioned on one side of the steam condensation section heat exchanger close to the hot air inlet, and the outlet of the water draining and supercooling section heat exchanger is used for being connected with the deaerator; the inlet of the heat exchanger of the drainage supercooling section is connected with the outlet of the heat exchanger of the steam condensation section through a drainage pipeline, a drainage valve and a drainage bypass connected with the drainage valve in parallel are arranged on the drainage pipeline, and a drainage regulating valve with adjustable opening degree is arranged on the drainage bypass; the air temperature sensor is used for detecting the outlet air temperature of the steam condensation section heat exchanger; and the controller is used for controlling the opening of the drain control valve according to the outlet air temperature of the steam condensation section heat exchanger.
Description
Technical Field
The invention relates to the technical field of waste incineration, in particular to a steam-air preheater system.
Background
Because the moisture content is higher in domestic rubbish, need hot-blast to carry out the drying to rubbish to promote rubbish more stable, faster, safer burning, improve combustion efficiency. At present, most of garbage incinerators adopt a steam-air preheater arranged outside a boiler as a wind heating facility to heat air so as to form hot wind.
The steam-air preheater system comprises a condensing section for realizing heat exchange between steam and air and a supercooling section for realizing heat exchange between saturated water generated by steam condensation and the air. At present, drain generated by a condensation section enters a supercooling section through a mechanical drain valve, and the valve core risks jamming due to the high failure rate of the mechanical drain valve; or if the trap is in a closed state or is clamped at a certain position of the open state, the trap cannot be completely opened, so that the trap is blocked, the trap cannot be timely discharged, fluid in a condensation section flows smoothly, the heat exchange coefficient is reduced, and the heat exchange efficiency is influenced. And the drainage behind the trap is naturally cooled, and the cooling speed is slower, also can cause hydrophobic jam, can not in time discharge hydrophobic, leads to the condensation segment fluid flow not smooth, and the heat transfer coefficient reduces, influences heat exchange efficiency equally.
In addition, the hydrophobic temperature of trap corresponds the saturation temperature of vapor pressure greatly, because the pressure reduces by a wide margin behind the hydrophobic valve, the saturation temperature that corresponds reduces, it can take place the vaporization to drain, produce a large amount of steam, the great harm can be produced to the pipeline to the washing away of steam in the pipeline, seriously influence steam-air heater's heat transfer effect and equipment pipeline life, still can cause excessive hot hydrophobic entering deaerator, cause the self boiling of deaerator easily, lead to the deaerator internal pressure to rise, the steam extraction volume increases, the soda loss increase, still can lead to the soda reverse flow in the deaerator, the deaerator's deoxidization effect worsens etc..
Disclosure of Invention
In view of the above, the present invention is directed to a steam-air preheater system to improve heat exchange efficiency.
In order to achieve the purpose, the invention discloses the following technical scheme:
a steam-air preheater system comprising:
the preheater body is provided with an air heating cavity, a cold air inlet for cold air to enter the air heating cavity and a hot air outlet for hot air to be discharged from the air heating cavity;
the steam condensation section heat exchanger is arranged in the air heating cavity and close to the hot air outlet, and an inlet of the steam condensation section heat exchanger is used for being connected with a steam pipeline;
the water draining and supercooling section heat exchanger is arranged in the air heating cavity and is positioned on one side of the steam condensation section heat exchanger close to the hot air inlet, and the outlet of the water draining and supercooling section heat exchanger is used for being connected with a deaerator;
the inlet of the drainage supercooling section heat exchanger is connected with the outlet of the steam condensation section heat exchanger through a drainage pipeline, a drainage valve and a drainage bypass which is connected with the drainage valve in parallel are arranged on the drainage pipeline, and a drainage regulating valve with adjustable opening degree is arranged on the drainage bypass;
further comprising:
an air temperature sensor for detecting the outlet air temperature of the steam condensation section heat exchanger;
and the controller is used for controlling the opening of the hydrophobic adjusting valve according to the outlet air temperature of the steam condensation section heat exchanger.
Preferably, in the steam-air preheater system, the opening degree of the drain regulating valve is sequentially divided into a plurality of gears from small to large;
when the temperature of outlet air of the steam condensation section heat exchanger is lower than an air target temperature value, reaches an air target temperature difference value and lasts for a target time period, the controller controls the opening degree of the drain control valve to be increased by one gear; when the outlet air temperature of the steam condensation section heat exchanger is higher than an air target temperature value and reaches the air target temperature difference value and continues for the target time period, the controller controls the opening degree of the hydrophobic adjusting valve to be reduced by one gear so as to control the difference value between the outlet air temperature of the steam condensation section heat exchanger and the air target temperature value to be maintained within the air target temperature difference value.
Preferably, the steam-air preheater system further includes:
the auxiliary heat exchanger of the drainage supercooling section is arranged in the air heating cavity and is positioned on one side, close to the hot air inlet, of the steam condensing section heat exchanger, an outlet of the auxiliary heat exchanger of the drainage supercooling section is used for converging with an outlet of the heat exchanger of the drainage supercooling section and then is connected with the deaerator, and an inlet of the auxiliary heat exchanger of the drainage supercooling section is connected with an outlet of the drain valve in parallel through an auxiliary drainage branch and an inlet of the heat exchanger of the drainage supercooling section through a main drainage branch;
the hydrophobic temperature sensor is used for detecting the hydrophobic temperature of an outlet after the outlet of the hydrophobic supercooling section auxiliary heat exchanger and the outlet of the hydrophobic supercooling section heat exchanger converge;
the drainage flow regulating valve is used for regulating drainage flow in the auxiliary drainage branch and the main drainage branch;
the controller can control the drainage flow regulating valve to increase the drainage flow in the auxiliary drainage branch when the outlet drainage temperature is higher than a drainage target temperature value; when the outlet drain temperature is lower than the drain target temperature value, the drain flow regulating valve can be controlled to reduce the drain flow in the auxiliary drain branch.
Preferably, in the above steam-air preheater system, the steam condensing section heat exchanger comprises:
the inlet of the high-pressure steam condensing section is connected with a high-pressure steam pipeline,
the low-pressure steam condensing section is positioned on the air inlet side of the high-pressure steam condensing section, and the inlet of the low-pressure steam condensing section is used for being connected with a low-pressure steam pipeline;
the heat exchanger with the hydrophobic supercooling section comprises:
the inlet of the high-pressure drainage supercooling section is connected with the outlet of the high-pressure steam condensation section through a high-pressure drainage pipeline, and the high-pressure drainage pipeline is provided with a high-pressure drainage valve;
the inlet of the low-pressure drainage supercooling section is connected with the outlet of the low-pressure steam condensation section through a low-pressure drainage pipeline, and a low-pressure drainage valve is arranged on the low-pressure drainage pipeline;
wherein the drain bypass comprises a high pressure drain bypass in parallel with the high pressure drain valve and a low pressure drain bypass in parallel with the low pressure drain valve;
the drain regulating valve comprises a high-pressure drain regulating valve arranged on the high-pressure drain bypass and a low-pressure drain regulating valve arranged on the low-pressure drain bypass;
the air temperature sensor comprises a first temperature sensor for detecting the outlet air temperature of the high-pressure steam condensing section and a second temperature sensor for detecting the outlet air temperature of the low-pressure steam condensing section;
the controller controls the opening of the high-pressure hydrophobic adjusting valve according to the outlet air temperature of the high-pressure steam condensing section, and controls the opening of the low-pressure hydrophobic adjusting valve according to the outlet air temperature of the low-pressure steam condensing section.
Preferably, in the above steam-air preheater system, the auxiliary heat exchanger of the drain subcooling section and the high-pressure drain subcooling section are connected in parallel with the outlet of the high-pressure drain valve;
the drain temperature sensor is used for detecting the drain temperature of an outlet after the outlets of the high-pressure drain supercooling section and the drain supercooling section heat exchanger converge;
and the drainage flow regulating valve controls the drainage flow in the auxiliary drainage branch and the main drainage branch according to the outlet drainage temperature of the high-pressure drainage supercooling section.
Preferably, in the steam-air preheater system, the drain flow control valve is a three-way control valve, an inlet of the three-way control valve is connected to an outlet of the high-pressure drain valve, and two outlets of the three-way control valve are respectively connected to the auxiliary drain branch and the main drain branch.
Preferably, in the above steam-air preheater system, the auxiliary heat exchanger of the drain supercooling section, the low-pressure drain supercooling section, the high-pressure drain supercooling section, the low-pressure steam condensing section, and the high-pressure steam condensing section are sequentially arranged along a flow direction of air in the air heating chamber.
Preferably, in the above steam-air preheater system, the target temperature difference of the air is 5 to 15 ℃.
Preferably, in the above steam-air preheater system, the target time period is from 5 to 15 minutes.
Preferably, in the steam-air preheater system, an inlet of the steam condensing section heat exchanger is connected with a steam inlet pipeline connected with a steam pipeline, and the steam inlet pipeline is provided with a steam regulating valve;
the controller is connected with the steam regulating valve and controls the opening degree of the steam regulating valve according to the outlet air temperature of the steam condensing section heat exchanger.
According to the technical scheme, the steam-air preheater system comprises a preheater body, a steam-air preheater and a steam-air preheater, wherein the preheater body is provided with an air heating cavity, a cold air inlet for supplying cold air into the air heating cavity and a hot air outlet for supplying hot air exhausted from the air heating cavity; the steam condensation section heat exchanger is arranged in the air heating cavity and close to the hot air outlet, and an inlet of the steam condensation section heat exchanger is used for being connected with a steam pipeline; the water draining and supercooling section heat exchanger is arranged in the air heating cavity and is positioned on one side of the steam condensation section heat exchanger close to the hot air inlet, and the outlet of the water draining and supercooling section heat exchanger is used for being connected with the deaerator; the inlet of the heat exchanger of the drainage supercooling section is connected with the outlet of the heat exchanger of the steam condensation section through a drainage pipeline, a drainage valve and a drainage bypass connected with the drainage valve in parallel are arranged on the drainage pipeline, and a drainage regulating valve with adjustable opening degree is arranged on the drainage bypass; the air temperature sensor is used for detecting the outlet air temperature of the steam condensation section heat exchanger; and the controller is used for controlling the opening of the drain control valve according to the outlet air temperature of the steam condensation section heat exchanger.
When the steam-air preheater system is applied, an inlet of the steam condensing section heat exchanger is connected with a steam pipeline, and an outlet of the drainage supercooling section heat exchanger is connected with a deaerator. In the working process, on one hand, cold air enters the air heating cavity from the cold air inlet, the air is heated by the hydrophobic supercooling section heat exchanger and the steam condensation section heat exchanger in sequence, and the obtained hot air is discharged from the air heating cavity from the hot air outlet; on the other hand, saturated drain is formed after steam enters the steam condensation section heat exchanger and exchanges heat with air in the air heating cavity, the saturated drain enters the drain supercooling section heat exchanger through a drain valve of a drain pipeline, the outlet air temperature of the steam condensation section heat exchanger is detected through an air temperature sensor, the opening of a drain regulating valve is controlled by a controller according to the outlet air temperature of the steam condensation section heat exchanger, the saturated drain can enter the drain supercooling section heat exchanger through the drain regulating valve of a drain bypass at the same time, the saturated drain in the drain supercooling section heat exchanger further exchanges heat with the air in the air heating cavity to form supercooled water, and finally the supercooled water enters the deaerator to be recycled.
Therefore, after the steam trap breaks down, the opening of the drain regulating valve is controlled according to the outlet air temperature of the steam condensation section heat exchanger, so that saturated drain in front of the steam trap can be discharged to the drain supercooling section heat exchanger in time through the drain bypass, the smooth flow of fluid in the steam condensation section heat exchanger is maintained, the heat exchange coefficient of a heat exchange surface is ensured, and the heat exchange efficiency is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a steam-air preheater system as disclosed in an embodiment of the present invention.
Detailed Description
The embodiment of the invention discloses a steam-air preheater system, which improves the heat exchange efficiency.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, a steam-air preheater system disclosed in an embodiment of the present invention includes a preheater body provided with an air heating chamber, a cool air inlet through which cool air enters the air heating chamber, and a hot air outlet through which hot air is discharged from the air heating chamber; the steam condensation section heat exchanger is arranged in the air heating cavity and close to the hot air outlet, and an inlet of the steam condensation section heat exchanger is used for being connected with a steam pipeline; the water draining and supercooling section heat exchanger is arranged in the air heating cavity and is positioned on one side of the steam condensation section heat exchanger close to the hot air inlet, and the outlet of the water draining and supercooling section heat exchanger is used for being connected with the deaerator; the inlet of the heat exchanger of the drainage supercooling section is connected with the outlet of the heat exchanger of the steam condensation section through a drainage pipeline, a drainage valve and a drainage bypass connected with the drainage valve in parallel are arranged on the drainage pipeline, and a drainage regulating valve with adjustable opening degree is arranged on the drainage bypass; the air temperature sensor is used for detecting the outlet air temperature of the steam condensation section heat exchanger; and the controller is used for controlling the opening of the drain control valve according to the outlet air temperature of the steam condensation section heat exchanger.
It should be noted that the drain valve is a valve for a drain pipeline, and can play a role of 'blocking steam and draining water'; the drain control valve is an electric control valve used on a drain pipeline and is commonly used for controlling the drain flow.
When the steam-air preheater system is applied, an inlet of the steam condensing section heat exchanger is connected with a steam pipeline, and an outlet of the drainage supercooling section heat exchanger is connected with a deaerator. In the working process, on one hand, cold air enters the air heating cavity from the cold air inlet, the air is heated by the hydrophobic supercooling section heat exchanger and the steam condensation section heat exchanger in sequence, and the obtained hot air is discharged from the air heating cavity from the hot air outlet; on the other hand, saturated drain is formed after steam enters the steam condensation section heat exchanger and exchanges heat with air in the air heating cavity, the saturated drain enters the drain supercooling section heat exchanger through a drain valve of a drain pipeline, the outlet air temperature of the steam condensation section heat exchanger is detected through an air temperature sensor, the opening of a drain regulating valve is controlled by a controller according to the outlet air temperature of the steam condensation section heat exchanger, the saturated drain can enter the drain supercooling section heat exchanger through the drain regulating valve of a drain bypass at the same time, the saturated drain in the drain supercooling section heat exchanger further exchanges heat with the air in the air heating cavity to form supercooled water, and finally the supercooled water enters the deaerator to be recycled.
Therefore, after the steam trap breaks down, the opening of the drain regulating valve is controlled according to the outlet air temperature of the steam condensation section heat exchanger, so that saturated drain in front of the steam trap can be discharged to the drain supercooling section heat exchanger in time through the drain bypass, the smooth flow of fluid in the steam condensation section heat exchanger is maintained, the heat exchange coefficient of a heat exchange surface is ensured, and the heat exchange efficiency is improved.
In a preferred embodiment, the opening degree of the drainage regulating valve is sequentially divided into a plurality of gears from small to large; when the outlet air temperature of the steam condensation section heat exchanger is lower than an air target temperature value, reaches an air target temperature difference value and lasts for a target time period, the controller controls the opening degree of the drain control valve to be increased by one gear; when the outlet air temperature of the steam condensation section heat exchanger is higher than the air target temperature value, reaches the air target temperature difference value and lasts for the target time period, the controller controls the opening degree of the drain control valve to be reduced by one gear so as to control the difference value between the outlet air temperature of the steam condensation section heat exchanger and the air target temperature value to be maintained within the air target temperature difference value.
Specifically, the opening of the hydrophobic control valve is set from 20% to 80% to 6 (20%, 40%, 50%, 60%, 70%, 80%, respectively). And when the valve operates normally, the drain regulating valve is in a closed state. When the outlet air temperature of the steam condensation section heat exchanger is lower than the air target temperature value and exceeds the air target temperature difference value for a target time period, the hydrophobic regulating valve is opened, and is firstly opened by 20%. If the outlet air temperature of the steam condensation section heat exchanger is continuously lower than the air target temperature value and exceeds the air target temperature difference value for a target time period, the opening degree of the hydrophobic regulating valve is continuously increased by one gear and is opened by 40%; and if the outlet air temperature of the steam condensation section heat exchanger is still lower than the air target temperature value and exceeds the air target temperature difference value for a target time period, the opening degree of the hydrophobic regulating valve is gradually increased. If the outlet air temperature of the steam condensation section heat exchanger is higher than the air target temperature value and exceeds the air target temperature difference value for a target time period, closing the drain control valve for one gear; if the outlet air temperature of the steam condensation section heat exchanger is continuously higher than the air target temperature value and exceeds the air target temperature difference value for a target time period, continuously closing the opening of the hydrophobic regulating valve for one gear; and if the outlet air temperature of the steam condensation section heat exchanger is still higher than the target air temperature value and exceeds the target air temperature difference value for a target time period, the opening degree of the hydrophobic regulating valve is gradually reduced. Until the difference between the outlet air temperature of the steam condensation section heat exchanger and the air target temperature value is controlled to be maintained within the air target temperature difference.
This embodiment guarantees when trap department is hydrophobic not smooth, can adjust hydrophobic governing valve's aperture step by step automatically, in time with the hydrophobic discharge of retardation, guarantees high pressure condensation section heat transfer performance, and is better to the regulation stationarity of the export air temperature of steam condensation section heat exchanger, avoids the temperature fluctuation too big. Of course, the opening degree of the drain control valve can also be divided into other gears; this application can also make hydrophobic governing valve's aperture crescent or reduce, does not adjust according to keeping off the position.
In order to optimize the technical scheme, the steam-air preheater system further comprises a drain supercooling section auxiliary heat exchanger 1 which is arranged in the air heating cavity and located on one side, close to a hot air inlet, of the steam condensing section heat exchanger, an outlet of the drain supercooling section auxiliary heat exchanger 1 is used for converging with an outlet of the drain supercooling section heat exchanger and then is connected with a deaerator, and an inlet of the drain supercooling section auxiliary heat exchanger 1 is connected with an outlet of a drain valve in parallel through an auxiliary drain branch and an inlet of the drain supercooling section heat exchanger through a main drain branch; the hydrophobic temperature sensor is used for detecting the hydrophobic temperature of an outlet after the outlet of the hydrophobic supercooling section auxiliary heat exchanger 1 and the outlet of the hydrophobic supercooling section heat exchanger converge; the drainage flow regulating valve is used for regulating drainage flow in the auxiliary drainage branch and the main drainage branch; the controller can control the drainage flow regulating valve to increase drainage flow in the auxiliary drainage branch when outlet drainage temperature is higher than a drainage target temperature value, and control the drainage flow regulating valve to decrease drainage flow in the auxiliary drainage branch when the outlet drainage temperature is lower than the drainage target temperature value.
According to the method, both the added auxiliary heat exchanger 1 of the drainage supercooling section and the heat exchanger of the drainage supercooling section can be used for enabling saturated drainage obtained after heat exchange of the heat exchanger of the steam condensation section to flow in, and the temperature of air flowing through the auxiliary heat exchanger 1 of the drainage supercooling section is lower than that of air flowing through the heat exchanger of the steam condensation section, so that when the drainage temperature of an outlet, detected by a drainage temperature sensor, of the auxiliary heat exchanger 1 of the drainage supercooling section and an outlet of the heat exchanger of the drainage supercooling section after confluence is higher than a drainage target temperature value, a controller controls a drainage flow regulating valve to increase drainage flow in an auxiliary drainage branch, and therefore drainage flow of heat exchange with air with lower temperature is increased; when the outlet drain temperature detected by the drain temperature sensor after the outlet of the auxiliary heat exchanger 1 of the drain supercooling section and the outlet of the heat exchanger of the drain supercooling section converge is lower than the drain target temperature value, the controller controls the drain flow regulating valve to reduce the drain flow in the auxiliary drain branch, so that the drain flow exchanging heat with the air with lower temperature is reduced, and the outlet drain temperature is maintained at the drain target temperature value.
The invention avoids a large amount of flash steam in the drain main pipe connected with the outlet of the drain supercooling section heat exchanger, improves the heat exchange efficiency of the air preheater and prolongs the service life of the pipeline; the problem that when the drainage quantity of a drainage valve is suddenly increased, the drainage temperature of an air preheater is high, and a gas-liquid two-phase flow phenomenon exists can be solved.
It can be understood that, when the outlet drain temperature is higher than or lower than the drain target temperature value and exceeds the drain target temperature difference, the controller of the present application may also control the drain flow regulating valve to increase or decrease the drain flow in the auxiliary drain branch so as to maintain the outlet drain temperature within the drain target temperature difference of the drain target temperature value.
In a specific embodiment, as shown in fig. 1, the steam condensing section heat exchanger includes a high-pressure steam condensing section 5, an inlet of which is used for connecting with a high-pressure steam pipeline, a low-pressure steam condensing section 4 located at an air inlet side of the high-pressure steam condensing section 5, and an inlet of the low-pressure steam condensing section 4 is used for connecting with a low-pressure steam pipeline; the heat exchanger of the drainage supercooling section comprises a high-pressure drainage supercooling section 3, the inlet of the high-pressure drainage supercooling section is connected with the outlet of the high-pressure steam condensation section 5 through a high-pressure drainage pipeline, and a high-pressure drainage valve 7 is arranged on the high-pressure drainage pipeline; the inlet of the low-pressure drainage supercooling section 2 is connected with the outlet of the low-pressure steam condensation section 4 through a low-pressure drainage pipeline, and a low-pressure drainage valve 6 is arranged on the low-pressure drainage pipeline;
the drainage bypass comprises a high-pressure drainage bypass connected with the high-pressure drainage valve 7 in parallel and a low-pressure drainage bypass connected with the low-pressure drainage valve 6 in parallel; the drain control valve comprises a high-pressure drain control valve 9 arranged on the high-pressure drain bypass and a low-pressure drain control valve 8 arranged on the low-pressure drain bypass; the air temperature sensor comprises a first temperature sensor for detecting the outlet air temperature of the high-pressure steam condensation section 5 and a second temperature sensor for detecting the outlet air temperature of the low-pressure steam condensation section 4; the controller controls the opening of the high-pressure drain trap regulating valve 9 according to the outlet air temperature of the high-pressure steam condensing section 5, and controls the opening of the low-pressure drain trap regulating valve 8 according to the outlet air temperature of the low-pressure steam condensing section 4.
It should be noted that the high-pressure steam condensing section 5 is a heat exchange section for steam extraction and air of the steam drum, the steam extraction heat exchange of the steam drum becomes saturated water, and the air is heated to 220 ℃.
The low-pressure steam condensing section 4 is a heat exchange section for steam extraction and air of the steam turbine, the steam extracted by the steam turbine is converted into saturated water after heat exchange, and the air is heated to 150 ℃.
The high-pressure drainage supercooling section 3 is used for enabling saturated water generated by condensation of high-pressure steam and air to be converted into supercooled water after heat exchange;
the low-pressure drainage supercooling section 2 is used for enabling saturated water generated by low-pressure steam condensation and air to be converted into supercooled water after heat exchange.
In the working process, high-pressure steam forms high-pressure saturated drainage after heat exchange in the high-pressure steam condensation section 5, the high-pressure saturated drainage enters the high-pressure drainage supercooling section 3 through the high-pressure drainage valve 7, and after supercooled water is formed through further heat exchange, the high-pressure saturated drainage enters the deaerator through the high-pressure drainage main pipe. Low-pressure steam forms low-pressure saturated drain after heat exchange in the low-pressure steam condensation section 4, the low-pressure saturated drain enters the low-pressure drain supercooling section 2 through the low-pressure drain valve 6, and after supercooled water is formed through further heat exchange, the low-pressure saturated drain enters the deaerator through the low-pressure drain main pipe.
The high-pressure drain valve 7 is adjusted through the outlet air temperature of the high-pressure steam condensation section 5, the low-pressure drain valve 6 is adjusted through the outlet air temperature of the low-pressure steam condensation section 4, and the air target temperature values selected by the outlet air temperatures at the two positions are different.
Set up high-pressure hydrophobic control valve 9 at the hydrophobic bypass of high pressure, the export air temperature through high-pressure steam condensation section 5 is the aperture of air preheater export air temperature regulation high-pressure hydrophobic control valve 9 promptly, guarantees to be in high-pressure drain valve 7 department when hydrophobic not smooth, can open high-pressure hydrophobic control valve 9 step by step automatically, in time with the hydrophobic discharge of retardation, guarantees high-pressure steam condensation section 5 heat transfer performance.
Set up low pressure hydrophobic control valve 8 at the hydrophobic bypass of low pressure, through the export air temperature regulation low pressure hydrophobic control valve 8's of low pressure steam condensation section 4 aperture, guarantee at low pressure drain valve 6 department when hydrophobic is not smooth, can open low pressure hydrophobic control valve 8 step by step automatically, in time with the hydrophobic discharge of retardation, guarantee 4 heat transfer performance of low pressure steam condensation section.
In the embodiment, the steam condensing section heat exchanger adopts the high-pressure steam condensing section 5 and the low-pressure steam condensing section 4 to heat steam on two sides of air, so that the heat exchange efficiency is higher; and the high-pressure drain and the low-pressure drain are cooled to more than 50 ℃ through the supercooling section, so that the risk of flash evaporation of the drain in a pipeline is reduced. Of course, the steam condensing section heat exchanger can also adopt the high-pressure steam condensing section 5.
In the preferred technical scheme, the auxiliary heat exchanger 1 of the drainage supercooling section and the high-pressure drainage supercooling section 3 are connected with the outlet of the high-pressure drain valve 7 in parallel; the drain temperature sensor is used for detecting the drain temperature of an outlet after the outlet of the high-pressure drain supercooling section 3 and the outlet of the drain supercooling section heat exchanger converge; and the drainage flow regulating valve controls the drainage flow in the auxiliary drainage branch and the main drainage branch according to the outlet drainage temperature of the high-pressure drainage supercooling section 3.
In the embodiment, the outlets of the high-pressure drainage supercooling section 3 and the drainage supercooling section auxiliary heat exchanger 1 are converged and then connected with the high-pressure drainage main pipe, at the moment, the drainage supercooling section auxiliary heat exchanger 1 serves as an additional section of the high-pressure drainage supercooling section 3, and the drainage temperature sensor detects the outlet drainage temperature after convergence by detecting the temperature of the high-pressure drainage main pipe; when the temperature of the high-pressure drainage main pipe is higher than a drainage target temperature value, the controller controls the drainage flow regulating valve to increase the drainage flow in the auxiliary drainage branch, so that a part of high-pressure drainage is converged with the high-pressure drainage flowing out of the high-pressure drainage supercooling section 3 after passing through the auxiliary heat exchanger 1 of the drainage supercooling section for heat exchange, namely the heat exchange area of the high-pressure drainage supercooling section 3 is increased, and the drainage temperature is reduced; when the temperature of the high-pressure drainage main pipe is lower than a drainage target temperature value, the controller controls the drainage flow regulating valve to increase the drainage flow in the auxiliary drainage branch, and the high-pressure drainage amount of heat exchange of the auxiliary heat exchanger 1 in the drainage supercooling section is reduced, so that the drainage temperature is reduced, and the temperature of the high-pressure drainage main pipe is maintained at the drainage target temperature value.
Because the high-pressure saturated water formed after the high-pressure steam heat exchange is higher in temperature and is easier to generate steam, the auxiliary heat exchanger 1 of the drainage and supercooling section is preferably arranged behind the high-pressure drain valve 7. It can be understood that the application can also arrange the auxiliary heat exchanger 1 of the drainage supercooling section after the low-pressure drain valve 6.
In order to simplify the structure, the drainage flow regulating valve is a three-way regulating valve 10, the inlet of the three-way regulating valve 10 is connected with the outlet of the high-pressure drainage valve 7, and the two outlets are respectively connected with the auxiliary drainage branch and the main drainage branch. The three-way regulating valve 10 is an electric regulating valve capable of dividing one path of fluid into two paths of adjustable flow and flowing out. The three-way regulating valve 10 is arranged on the high-pressure drain pipeline, the controller controls the water dredging amount passing through the auxiliary heat exchanger 1 of the drain supercooling section and the high-pressure drain supercooling section 3 by controlling the opening degree of the three-way regulating valve 10, the temperature of the high-pressure drain main pipe is regulated, the drain temperature is further controlled to be maintained at a drain target temperature value, a large amount of flash steam in the drain main pipe is avoided, and the service life of the pipeline is prolonged.
It can be understood that the invention can also set up a damper valve in the auxiliary drainage branch and main drainage branch separately, regulate the flowrate of every branch separately, in order to realize the same technical effect of controlling the hydrophobic quantity of water through the auxiliary heat exchanger 1 of the drainage supercooling section and high-pressure drainage supercooling section 3.
In order to realize better heating effect, the auxiliary heat exchanger 1 of the drainage and supercooling section, the low-pressure drainage and supercooling section 2, the high-pressure drainage and supercooling section 3, the low-pressure steam condensing section 4 and the high-pressure steam condensing section 5 are sequentially arranged along the flowing direction of the air in the air heating cavity. The invention has 5 heat exchange sections, which are sequentially arranged along the air flowing direction: the auxiliary heat exchanger 1 of the drainage supercooling section, the low-pressure drainage supercooling section 2, the high-pressure drainage supercooling section 3, the low-pressure steam condensing section 4 and the high-pressure steam condensing section 5 are sequentially arranged, and the heat exchange efficiency of each heat exchange section is increased progressively, so that the heat energy utilization rate is higher.
The target air temperature difference is 5-15 deg.C and the target time period is 5-15 minutes. Specifically, the target temperature difference of the air is 10 ℃ and the target time period is 10 minutes.
The opening degree of the low-pressure drain regulating valve 8 is set to 6 gears (20%, 40%, 50%, 60%, 70% and 80% respectively) from 20-80%; in normal operation, the low-pressure drain control valve 8 is in a closed state. When the outlet air temperature of the low-pressure steam condensation section 4 is less than the low-pressure air target temperature value by more than 10 ℃ for 10 minutes, the low-pressure hydrophobic adjustment valve 8 is opened, and is firstly opened by 20%. If the temperature of the outlet air of the low-pressure steam condensation section 4 is continuously lower than the target temperature value of the low-pressure air and exceeds 10 ℃ for 10 minutes, the opening degree of the low-pressure hydrophobic regulating valve 8 is continuously increased by one gear and is opened by 40%; if the temperature of the air at the outlet of the low-pressure steam condensation section 4 is still lower than the target temperature value of the low-pressure air and exceeds 10 ℃ for 10 minutes, the opening degree of the low-pressure hydrophobic regulating valve 8 is gradually increased. If the temperature of the air at the outlet of the low-pressure steam condensation section 4 is higher than the target temperature value of the low-pressure air by more than 10 ℃ and lasts for 10 minutes, the low-pressure hydrophobic regulating valve 8 is closed for one step; if the temperature of the air at the outlet of the low-pressure steam condensation section 4 is continuously higher than the target temperature value of the low-pressure air by more than 10 ℃ and lasts for 10 minutes, the opening of the low-pressure hydrophobic regulating valve 8 is continuously reduced by one step; if the temperature of the air at the outlet of the low-pressure steam condensation section 4 is still higher than the target temperature value of the low-pressure air by more than 10 ℃ and lasts for 10 minutes, the opening degree of the low-pressure hydrophobic regulating valve 8 is gradually reduced. Until the temperature of the outlet air of the low-pressure steam condensation section 4 and the target temperature value of the low-pressure air are controlled to be kept stable within the range of (-10 ℃ and +10 ℃).
The opening degree of the high-pressure hydrophobic regulating valve 9 is set to 6 gears (20%, 40%, 50%, 60%, 70% and 80% respectively) from 20-80%; in normal operation, the high-pressure drain control valve 9 is in a closed state. When the outlet air temperature of the high-pressure steam condensation section 5 is lower than the target high-pressure air temperature value by more than 10 ℃ for 10 minutes, the high-pressure hydrophobic regulating valve 9 is opened, and is firstly opened by 20%. If the temperature of the outlet air of the high-pressure steam condensation section 5 is continuously lower than the target temperature value of the high-pressure air and exceeds 10 ℃ for 10 minutes, the opening degree of the high-pressure hydrophobic regulating valve 9 is continuously increased by one gear and is opened by 40%; if the temperature of the air at the outlet of the high-pressure steam condensation section 5 is still lower than the target temperature value of the high-pressure air and exceeds 10 ℃ for 10 minutes, the opening of the high-pressure hydrophobic regulating valve 9 is gradually increased. If the temperature of the air at the outlet of the high-pressure steam condensation section 5 is higher than the target temperature value of the high-pressure air by more than 10 ℃ and lasts for 10 minutes, the high-pressure hydrophobic regulating valve 9 is closed for one step; if the temperature of the air at the outlet of the high-pressure steam condensation section 5 is continuously higher than the target temperature value of the high-pressure air by more than 10 ℃ and lasts for 10 minutes, the opening of the high-pressure hydrophobic regulating valve 9 is continuously reduced by one step; if the temperature of the air at the outlet of the high-pressure steam condensation section 5 is still higher than the target temperature value of the high-pressure air by more than 10 ℃ and lasts for 10 minutes, the opening degree of the high-pressure hydrophobic regulating valve 9 is gradually reduced. Until the temperature of the outlet air of the high-pressure steam condensation section 5 and the target temperature value of the high-pressure air are controlled to be kept stable within the range of (-10 ℃ and +10 ℃).
It is understood that other values of the air target temperature difference may be selected, such as 5 deg.C, 16 deg.C, etc.; the target time period may also be other times, such as 8 minutes, 18 minutes, etc.
In order to further optimize the technical scheme, an inlet of the steam condensation section heat exchanger is connected with a steam inlet pipeline which is connected with a steam pipeline, and a steam regulating valve 11 is arranged on the steam inlet pipeline; the controller is connected with the steam regulating valve 11 and controls the opening degree of the steam regulating valve 11 according to the outlet air temperature of the steam condensing section heat exchanger. The opening degree of the steam regulating valve 11 is controlled according to the outlet air temperature of the steam condensation section heat exchanger, so that the outlet air temperature of the steam condensation section heat exchanger can be better controlled.
Specifically, the high-pressure steam inlet pipeline which is used for being connected with the high-pressure steam pipeline in the high-pressure steam condensation section 5 is provided with the steam regulating valve 11, so that the controller is utilized to control the opening degree of the steam regulating valve 11 according to the outlet air temperature of the high-pressure steam condensation section 5, the high-pressure steam flow entering the high-pressure steam condensation section 5 is controlled, and the steam energy consumption can be saved while the air heating requirement is met.
It is understood that the present application may also be provided with a steam regulating valve 11 in the low pressure steam inlet line of the low pressure steam condensation section 4 for connection to the low pressure steam line.
The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A steam-air preheater system, comprising:
the preheater body is provided with an air heating cavity, a cold air inlet for cold air to enter the air heating cavity and a hot air outlet for hot air to be discharged from the air heating cavity;
the steam condensation section heat exchanger is arranged in the air heating cavity and close to the hot air outlet, and an inlet of the steam condensation section heat exchanger is used for being connected with a steam pipeline;
the water draining and supercooling section heat exchanger is arranged in the air heating cavity and is positioned on one side of the steam condensation section heat exchanger close to the hot air inlet, and the outlet of the water draining and supercooling section heat exchanger is used for being connected with a deaerator;
the inlet of the drainage supercooling section heat exchanger is connected with the outlet of the steam condensation section heat exchanger through a drainage pipeline, a drainage valve and a drainage bypass which is connected with the drainage valve in parallel are arranged on the drainage pipeline, and a drainage regulating valve with adjustable opening degree is arranged on the drainage bypass;
further comprising:
an air temperature sensor for detecting the outlet air temperature of the steam condensation section heat exchanger;
and the controller is used for controlling the opening of the hydrophobic adjusting valve according to the outlet air temperature of the steam condensation section heat exchanger.
2. The steam-air preheater system of claim 1, wherein the opening degree of the hydrophobic control valve is sequentially divided into a plurality of gears from small to large;
when the temperature of outlet air of the steam condensation section heat exchanger is lower than an air target temperature value, reaches an air target temperature difference value and lasts for a target time period, the controller controls the opening degree of the drain control valve to be increased by one gear; when the outlet air temperature of the steam condensation section heat exchanger is higher than an air target temperature value and reaches the air target temperature difference value and continues for the target time period, the controller controls the opening degree of the hydrophobic adjusting valve to be reduced by one gear so as to control the difference value between the outlet air temperature of the steam condensation section heat exchanger and the air target temperature value to be maintained within the air target temperature difference value.
3. A steam-air preheater system as recited in claim 2, further comprising:
the auxiliary heat exchanger (1) of the drainage supercooling section is arranged in the air heating cavity and is positioned on one side, close to the hot air inlet, of the steam condensation section heat exchanger, an outlet of the auxiliary heat exchanger (1) of the drainage supercooling section is used for converging with an outlet of the heat exchanger of the drainage supercooling section and then is connected with the deaerator, and an inlet of the auxiliary heat exchanger (1) of the drainage supercooling section is connected with an outlet of the drain valve in parallel through an auxiliary drainage branch and an inlet of the heat exchanger of the drainage supercooling section through a main drainage branch;
the hydrophobic temperature sensor is used for detecting the hydrophobic temperature of an outlet after the outlet of the hydrophobic supercooling section auxiliary heat exchanger (1) and the outlet of the hydrophobic supercooling section heat exchanger converge;
the drainage flow regulating valve is used for regulating drainage flow in the auxiliary drainage branch and the main drainage branch;
the controller can control the drainage flow regulating valve to increase the drainage flow in the auxiliary drainage branch when the outlet drainage temperature is higher than a drainage target temperature value; when the outlet drain temperature is lower than the drain target temperature value, the drain flow regulating valve can be controlled to reduce the drain flow in the auxiliary drain branch.
4. A steam-air preheater system according to claim 3, wherein said steam condensing section heat exchanger comprises:
a high-pressure steam condensing section (5), the inlet of which is connected with a high-pressure steam pipeline,
the low-pressure steam condensing section (4) is positioned on the air inlet side of the high-pressure steam condensing section (5), and the inlet of the low-pressure steam condensing section (4) is used for being connected with a low-pressure steam pipeline;
the heat exchanger with the hydrophobic supercooling section comprises:
the inlet of the high-pressure drainage supercooling section (3) is connected with the outlet of the high-pressure steam condensation section (5) through a high-pressure drainage pipeline, and a high-pressure drainage valve (7) is arranged on the high-pressure drainage pipeline;
the inlet of the low-pressure drainage supercooling section (2) is connected with the outlet of the low-pressure steam condensation section (4) through a low-pressure drainage pipeline, and a low-pressure drainage valve (6) is arranged on the low-pressure drainage pipeline;
wherein the drain bypass comprises a high pressure drain bypass in parallel with the high pressure drain valve (7) and a low pressure drain bypass in parallel with the low pressure drain valve (6);
the drain regulating valve comprises a high-pressure drain regulating valve (9) arranged on the high-pressure drain bypass and a low-pressure drain regulating valve (8) arranged on the low-pressure drain bypass;
the air temperature sensor comprises a first temperature sensor for detecting the outlet air temperature of the high-pressure steam condensing section (5) and a second temperature sensor for detecting the outlet air temperature of the low-pressure steam condensing section (4);
the controller controls the opening degree of the high-pressure hydrophobic regulating valve (9) according to the outlet air temperature of the high-pressure steam condensing section (5), and controls the opening degree of the low-pressure hydrophobic regulating valve (8) according to the outlet air temperature of the low-pressure steam condensing section (4).
5. Steam-air preheater system according to claim 4, characterized in that the hydrophobic subcooling section auxiliary heat exchanger (1) and the high-pressure hydrophobic subcooling section (3) are connected in parallel with the high-pressure trap (7) outlet;
the drain temperature sensor is used for detecting the drain temperature of an outlet after the high-pressure drain supercooling section (3) and the outlet of the drain supercooling section heat exchanger converge;
and the drainage flow regulating valve controls the drainage flow in the auxiliary drainage branch and the main drainage branch according to the outlet drainage temperature of the high-pressure drainage supercooling section (3).
6. Steam-air preheater system according to claim 5, characterized in that the hydrophobic flow control valve is a three-way control valve (10), the inlet of the three-way control valve (10) being connected to the high-pressure hydrophobic valve (7) outlet, both outlets being connected to the auxiliary hydrophobic branch and the main hydrophobic branch, respectively.
7. The steam-air preheater system according to claim 5, wherein the hydrophobic subcooling section auxiliary heat exchanger (1), the low-pressure hydrophobic subcooling section (2), the high-pressure hydrophobic subcooling section (3), the low-pressure steam condensing section (4) and the high-pressure steam condensing section (5) are arranged in sequence along the flow direction of air in the air heating chamber.
8. A steam-air preheater system as recited in claim 2, wherein said air target temperature difference is in the range of 5-15 ℃.
9. A steam-air preheater system as recited in claim 2, wherein said target time period is in the range of 5-15 minutes.
10. A steam-air preheater system according to claim 2, wherein the inlet of the steam condensing section heat exchanger is connected to a steam inlet line for connection to a steam line, the steam inlet line being provided with a steam regulating valve (11);
the controller is connected with the steam regulating valve (11) and controls the opening degree of the steam regulating valve (11) according to the outlet air temperature of the steam condensing section heat exchanger.
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| CN202111677512.8A CN114279252A (en) | 2021-12-31 | 2021-12-31 | Steam-air preheater system |
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| CN202111677512.8A CN114279252A (en) | 2021-12-31 | 2021-12-31 | Steam-air preheater system |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106705110A (en) * | 2016-09-30 | 2017-05-24 | 上海双木散热器制造有限公司 | Anti-corrosion steam air preheater pipeline system for waste incineration power generation |
| CN110410817A (en) * | 2019-03-30 | 2019-11-05 | 上海康恒环境股份有限公司 | A kind of three-stage steam type airheater draining system |
| CN110566936A (en) * | 2019-03-30 | 2019-12-13 | 上海康恒环境股份有限公司 | Four-section type steam air preheater drainage system |
| CN112050248A (en) * | 2020-09-10 | 2020-12-08 | 上海康恒环境股份有限公司 | Steam air preheater for household garbage incineration |
| CN112484073A (en) * | 2020-11-30 | 2021-03-12 | 光大环保技术装备（常州）有限公司 | Steam air preheating system for waste incineration industry and preheating method thereof |
| CN112594664A (en) * | 2020-12-16 | 2021-04-02 | 上海康恒环境股份有限公司 | Intelligent hydrophobic steam-air preheater system and automatic control method thereof |
-
2021
- 2021-12-31 CN CN202111677512.8A patent/CN114279252A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106705110A (en) * | 2016-09-30 | 2017-05-24 | 上海双木散热器制造有限公司 | Anti-corrosion steam air preheater pipeline system for waste incineration power generation |
| CN110410817A (en) * | 2019-03-30 | 2019-11-05 | 上海康恒环境股份有限公司 | A kind of three-stage steam type airheater draining system |
| CN110566936A (en) * | 2019-03-30 | 2019-12-13 | 上海康恒环境股份有限公司 | Four-section type steam air preheater drainage system |
| CN112050248A (en) * | 2020-09-10 | 2020-12-08 | 上海康恒环境股份有限公司 | Steam air preheater for household garbage incineration |
| CN112484073A (en) * | 2020-11-30 | 2021-03-12 | 光大环保技术装备（常州）有限公司 | Steam air preheating system for waste incineration industry and preheating method thereof |
| CN112594664A (en) * | 2020-12-16 | 2021-04-02 | 上海康恒环境股份有限公司 | Intelligent hydrophobic steam-air preheater system and automatic control method thereof |
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