CN114526495A - Variable heat source air heater system and control method thereof - Google Patents

Abstract

The invention discloses a variable heat source air heater system and a control method thereof.A water inlet and a water outlet of a low-temperature economizer are respectively provided with a low-economizer inlet shutoff valve and a low-economizer outlet shutoff valve; the inlet of the low-provincial inlet shutoff valve is communicated with the first low-provincial inlet water pipe through a low-provincial inlet pipeline, and the outlet of the low-provincial outlet shutoff valve is communicated with a low-provincial outlet pipeline; the low-provincial outlet pipeline is divided into two paths which are respectively communicated with the second low inlet and are respectively provided with a first shut-off valve and a second shut-off valve; a regulating valve is arranged on a pipeline connected with the first low feeding port and the second low feeding port; the water inlet of the air heater is communicated with the outlet of the low-provincial outlet shutoff valve through an inlet branch pipe of the air heater, the water outlet of the air heater is communicated with the inlet of the low-provincial inlet shutoff valve through an outlet branch pipe of the air heater, and the circulating water pump is arranged on the outlet branch pipe of the air heater. The system can realize the online adjustment of the heat source of the air heater, so that the air heater gets rid of the limitation of low-cost and fault-saving, the running reliability of the air heater system is improved, and the running safety and reliability of the air preheater are improved.

Description

A kind of variable heat source heater system and control method thereof

technical field

The invention belongs to the technical field of boiler energy saving, and in particular relates to a variable heat source air heater system and a control method thereof, so that the heat source of the air heater can be changed.

Background technique

With the continuous advancement of low-carbon environmental protection policies, thermal power units have completed ultra-low emission transformation. With the improvement of NOx index, the amount of ammonia injection in the denitrification system increases, the amount of ammonia escaping from the unit increases, and the air preheater often experiences hydrogen sulfate hinge deposition and clogging. phenomenon, with the popularization of low-temperature economizers, the unit uses the low-temperature economizer combined with the heater system to increase the air temperature at the inlet of the air preheater, increase the wall temperature of the cold section of the air preheater, and solve the problem of ammonium hydrogen sulfate clogging and corrosion of the air preheater. . Due to the increased operation time, the low-temperature economizer has been worn out, leaked, and even out of operation, resulting in no heat source available for the heater. The decrease of the outlet air temperature of the fan directly leads to the decrease of the cold end wall temperature of the air preheater, resulting in serious ash blocking of the air preheater, which has a great impact on the safe operation of the air preheater.

SUMMARY OF THE INVENTION

In order to solve the problems raised in the above background art. The invention provides a variable heat source heater system and a control method thereof. The system can realize on-line adjustment of the heat source of the heater, and can adjust the access point of the heat source according to the working conditions, so that the heater can get rid of low-cost failures. time limit, improve the operational reliability of the heater system.

To achieve the above object, the present invention provides the following technical solutions:

A variable heat source air heater system, including air heater, circulating water pump, low temperature economizer, No. Shut-off valve and low provincial outlet shut-off valve; the inlet of the low provincial inlet shut-off valve is connected to the No. 1 low inlet water pipe through the low provincial inlet pipe, and the outlet of the low provincial outlet shut-off valve is connected to the low provincial outlet pipe; The outlet pipeline is divided into two paths, and the two paths are respectively connected with the No. 2 low inlet and the outlet, and the two paths are respectively provided with a first shut-off valve and a second shut-off valve; the No. 1 low inlet and the No. 2 low inlet There is a regulating valve on the connected pipeline; the water inlet of the air heater is connected to the outlet of the low provincial outlet shut-off valve through the air heater inlet branch pipe, and the water outlet of the air heater is cut off from the low provincial inlet through the air heater outlet branch pipe The inlet of the valve is communicated, and the circulating water pump is arranged on the outlet branch pipe of the heater.

Preferably, the air outlet of the heater is provided with a heater outlet air temperature detection device.

Preferably, the flue gas outlet of the low-temperature economizer is provided with a flue gas temperature monitoring device at the low-temperature economizer outlet.

Preferably, a fan is connected to the air inlet of the heater, and the outlet of the fan communicates with the air inlet of the heater.

Preferably, the variable heat source air heater system of the present invention further comprises an air preheater, and the air outlet of the air heater communicates with the air inlet of the air preheater.

Preferably, the variable heat source heater system of the present invention further includes an electrostatic precipitator, and the flue gas outlet of the low-temperature economizer is communicated with the flue gas inlet of the electrostatic precipitator.

Preferably, an induced draft fan is connected to the flue gas outlet of the electrostatic precipitator.

Preferably, the variable heat source air heater system of the present invention further comprises a desulfurization tower, and the flue gas inlet of the desulfurization tower is communicated with the air outlet of the induced draft fan.

Preferably, the variable heat source air heater system of the present invention further comprises a chimney, and the flue gas outlet of the desulfurization tower communicates with the flue gas inlet of the chimney.

The control method of the above-mentioned variable heat source fan heater system of the present invention includes the following processes:

When the low-temperature economizer is normally put into operation, the inlet shut-off valve and the outlet shut-off valve of the lower province are all opened. By changing the frequency of the circulating water pump, the amount of water entering the heater can be adjusted to control the air temperature at the outlet of the heater; Adjust the valve opening, adjust the amount of water entering the low-temperature economizer, and control the outlet smoke temperature of the low-temperature economizer;

When the low temperature economizer is out of operation, the low provincial inlet shut-off valve and the low provincial outlet shut-off valve are all closed:

Summer and high load conditions: close the second shut-off valve, keep the first shut-off valve and the regulating valve fully open, adjust the amount of water entering the heater by changing the frequency of the circulating water pump, and control the air temperature at the outlet of the heater;

Winter and low load conditions: close the first shut-off valve, and keep the second shut-off valve and regulating valve fully open. By changing the frequency of the circulating water pump, adjust the amount of water entering the heater and control the air temperature at the outlet of the heater.

The present invention has the following beneficial effects:

The heater system capable of changing the heat source of the invention can realize on-line adjustment of the heat source of the heater. When the low temperature economizer is in normal operation, the heat source of the heater comes from the hot water at the outlet of the low temperature economizer, and when the low temperature economizer is out of operation At this time, the heat source of the heater comes from the regenerative system, and the access point of the heat source can be adjusted according to the working conditions, so that the heater can get rid of the limitation of low failure time and improve the operation reliability of the heater system.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the specification, and are used to explain the present invention together with the embodiments of the present invention, and do not constitute a limitation to the present invention. In the attached image:

Fig. 1 is the schematic diagram of the heater system of the present invention that can change the heat source;

Fig. 2 is the system schematic diagram of adopting the regenerative system as the heat source of the heater system capable of changing the heat source of the present invention in summer and high load conditions;

3 is a schematic diagram of a system using a regenerative system as a heat source for the heater system capable of changing the heat source of the present invention in winter and under low load conditions;

In the picture: 1. Air preheater; 2. Low temperature economizer; 3. Electrostatic precipitator; 4. Induced draft fan; 5. Desulfurization tower; 6. Chimney; 7. Ventilator; 8. Air heater; 9. Circulation Water pump; 12. Low-Province inlet shut-off valve; 13. Low-Province outlet shut-off valve; 14. First shut-off valve; 15. Second shut-off valve; 16. Control valve; 18. No. 1 low-plus; 19, No.2 Low Plus; 20. Air heater outlet air temperature detection device; 23. Low provincial outlet smoke temperature detection device; 26. Air heater inlet branch pipe; 27. Air heater outlet branch pipe; 28. Low provincial inlet pipe; 29 , Low provincial export pipeline.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Example

Referring to FIG. 1, the variable heat source heater system of the present invention includes an air preheater 1, an electrostatic precipitator 3, a desulfurization tower 5, a chimney 6, an air heater 8, a circulating water pump 9, a low-temperature economizer 2, and No. 1 Low plus 18 and No. 2 low plus 19, the inlet and outlet of the low-temperature economizer 2 are respectively provided with a low-level inlet shut-off valve 12 and a low-level outlet shut-off valve 13; the inlet of the low-level inlet shut-off valve 12 passes through The low-province inlet pipe 28 is connected with the No. 1 low-plus 18 inlet water pipe, and the outlet of the low-province outlet shut-off valve 13 is connected to a low-province outlet pipeline 29; The inlet and outlet of 19 are connected, and the two roads are respectively provided with a first shut-off valve 14 and a second shut-off valve 15; a regulating valve 16 is provided on the pipeline connecting the outlet of No. The water inlet of the air heater 8 is communicated with the outlet of the low provincial outlet shut-off valve 13 through the air heater inlet branch pipe 26, and the water outlet of the air heater 8 is connected with the inlet of the low provincial inlet shut-off valve 12 through the air heater outlet branch pipe 27 The circulating water pump 9 is arranged on the outlet branch pipe 27 of the heater. The air outlet of the heater 8 is provided with a heater outlet air temperature detection device 20 . The flue gas outlet of the low temperature economizer 2 is provided with a low economizer outlet flue gas temperature monitoring device 23 . A fan 7 is connected to the air inlet of the heater 8 , and the outlet of the fan 7 is communicated with the air inlet of the heater 8 . The air outlet of the air heater 8 is communicated with the air inlet of the air preheater 1 . The flue gas outlet of the low temperature economizer 2 is communicated with the flue gas inlet of the electrostatic precipitator 3 . An induced draft fan 4 is connected to the flue gas outlet of the electrostatic precipitator 3 . The flue gas inlet of the desulfurization tower 5 is communicated with the air outlet of the induced draft fan 4 . The flue gas outlet of the desulfurization tower 5 communicates with the flue gas inlet of the chimney 6 .

The control method of the above-mentioned variable heat source fan heater system of the present invention includes the following processes:

When the low-temperature economizer 2 is normally put into operation, the low-pressure inlet shut-off valve 12 and the low-pressure outlet shut-off valve 13 are all opened. By changing the frequency of the circulating water pump 9, the amount of water entering the air heater 8 is adjusted to control the outlet of the air heater. Air temperature; by adjusting the opening degree of the regulating valve 16, adjust the amount of water entering the low-temperature economizer 2, and control the outlet smoke temperature of the low-temperature economizer 2;

When the low temperature economizer 2 is out of operation, the low provincial inlet shut-off valve 12 and the low provincial outlet shut-off valve 13 are all closed:

Summer and high load conditions: close the second shut-off valve 15, keep the first shut-off valve 14 and the regulating valve 16 fully open, and adjust the amount of water entering the heater 8 by changing the frequency of the circulating water pump 9 to control the warm air outlet air temperature;

Winter and low load conditions: close the first shut-off valve 14, keep the second shut-off valve 15 and the regulating valve 16 fully open, and adjust the amount of water entering the heater 8 by changing the frequency of the circulating water pump 9 to control the warm air outlet air temperature.

The system can realize on-line adjustment of the heat source of the air heater. When the low-temperature economizer is in normal operation, the heat source of the air heater comes from the hot water outlet of the low-temperature economizer; when the low-temperature economizer is out of operation, the heat source of the air heater comes from the back and forth The heat source access point can be adjusted according to the working conditions, so that the heater can get rid of the limitation of low failure time, improve the operation reliability of the heater system, and improve the safety and reliability of the air preheater.

Finally, it should be noted that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, the The technical solutions described in the foregoing embodiments may be modified, or some technical features thereof may be equivalently replaced. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A heater system with a variable heat source, characterized in that it comprises a heater (8), a circulating water pump (9), a low-temperature economizer (2), a No. Add (19), the inlet and outlet of the low-temperature economizer (2) are respectively provided with a low provincial inlet shut-off valve (12) and a low provincial outlet shut-off valve (13); a low provincial inlet shut-off valve (12) The inlet of the valve is connected with the No. 1 low-plus (18) inlet water pipe through the low-province inlet pipe (28), and the outlet of the low-province outlet shut-off valve (13) is connected with the low-province outlet pipeline (29); the low-province outlet pipeline (29) It is divided into two paths, and the two paths are respectively connected with the inlet and outlet of the No. 2 low-pressure feeder (19), and the two roads are respectively provided with a first shut-off valve (14) and a second shut-off valve (15); (18) A regulating valve (16) is provided on the pipeline connecting the outlet to the inlet of the No. 2 low-pressure heater (19); the water inlet of the heater (8) is connected to the low-pressure outlet shut-off valve through the heater inlet branch pipe (26) The outlet of (13) is communicated, the water outlet of the heater (8) is communicated with the inlet of the lower inlet shut-off valve (12) through the outlet branch pipe (27) of the heater, and the circulating water pump (9) is arranged at the outlet of the heater on the branch pipe (27). 2 . The variable heat source heater system according to claim 1 , wherein the air outlet of the heater ( 8 ) is provided with a heater outlet air temperature detection device ( 20 ). 3 . 3. A variable heat source heater system according to claim 1, characterized in that the low-temperature economizer (2) is provided with a low-efficiency outlet flue gas temperature monitoring device (23) at the flue gas outlet. 4. A variable heat source heater system according to claim 1, wherein the air inlet of the heater (8) is connected with a ventilator (7), and the ventilator (7) outlet is connected to the air heater (8) The air inlet is connected. 5. The air heater system with a variable heat source according to claim 1, characterized in that it further comprises an air preheater (1), an air outlet of the air heater (8) and an air inlet of the air preheater (1). Connected. 6. A kind of variable heat source heater system according to claim 1, is characterized in that, also comprises electric precipitator (3), the flue gas outlet of low temperature economizer (2) and electric precipitator (3) ) is connected to the flue gas inlet. 7. A variable heat source fan heater system according to claim 6, characterized in that an induced draft fan (4) is connected to the flue gas outlet of the electrostatic precipitator (3). 8. a kind of heater system of variable heat source according to claim 7, is characterized in that, also comprises desulfurization tower (5), the flue gas inlet of desulfurization tower (5) and the air outlet of induced draft fan (4) Connected. 9. A kind of heater system of variable heat source according to claim 8, is characterized in that, also comprises chimney (6), the flue gas outlet of desulfurization tower (5) communicates with the flue gas inlet of chimney (6) . 10. The control method of the variable heat source heater system according to any one of claims 1-9, characterized in that it comprises the following process: When the low-temperature economizer (2) is normally put into operation, the low-pressure inlet shut-off valve (12) and the low-pressure outlet shut-off valve (13) are all opened. 8), the air temperature at the outlet of the heater is controlled; by adjusting the opening degree of the regulating valve (16), the amount of water entering the low-temperature economizer (2) is adjusted to control the outlet smoke temperature of the low-temperature economizer (2); When the low-temperature economizer (2) is out of operation, the low economizer inlet shut-off valve (12) and the low economizer outlet shut-off valve (13) are all closed: Summer and high load conditions: close the second shut-off valve (15), keep the first shut-off valve (14) and the regulating valve (16) fully open, and adjust the incoming warm air by changing the frequency of the circulating water pump (9). The water volume of the heater (8) is controlled to control the air temperature at the outlet of the heater; Winter and low load conditions: close the first shut-off valve (14), keep the second shut-off valve (15) and the regulating valve (16) fully open, and adjust the incoming warm air by changing the frequency of the circulating water pump (9). The water volume of the heater (8) is controlled to control the air temperature at the outlet of the heater.

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