Water medium air heater system and control method

Abstract

The invention discloses a water medium air heater system and a control method. The water medium air heater system comprises a fan, an air heater, an air preheater and an air temperature measuring point, wherein the fan, the air heater and the air preheater sequentially communicate through an air pipeline, and the air temperature measuring point is arranged at an air side outlet of the air heater;the water medium air heater system further comprises boiler feed water heaters I to III which are sequentially connected in series; the water medium air heater system further comprises an air heater water side inlet pipeline, an air heater water side outlet pipeline and a water pump and a water temperature measuring point, wherein the water pump and the water temperature measuring point are sequentially arranged on the inlet pipeline; one end of the inlet pipeline communicates with an outlet of the second boiler feed water heater; the other end of the inlet pipeline communicates with an inletof the air heater; one end of the outlet pipeline communicates with an inlet of the second boiler feed water heater; the other end of the outlet pipeline communicates with an outlet of the air heater;the water medium air heater system further comprises a recirculation pipeline and a recirculation valve which are used for adjusting the water inlet temperature of the air heater, wherein one end ofthe recirculation pipeline communicates with the outlet pipeline, and the other end of the recirculation pipeline communicates with an inlet of the water pump. According to the water medium air heatersystem, by using lower-grade boiler feed water as a heat source of the air heater, the economical efficiency is good, the air heater system automatically operates, and unattended operation is achieved.

Description

technical field [0001] The invention belongs to the technical field of boilers, and in particular relates to a water-medium air heater system and a control method, which can be used to increase the boiler inlet air temperature. Background technique [0002] With the continuous advancement of my country's low-carbon environmental protection policy, the economic and environmental indicators of boilers have been continuously improved, the energy-saving space has been continuously compressed, and the operating energy consumption has been continuously increased. Among them, the blockage of the air preheater is particularly prominent. The denitrification device is the main facility for nitrogen oxide removal, and its operating status directly affects the operating status of downstream devices. Currently, the operating status of the denitrification device is generally poor, and ammonia escape is serious, which is the direct cause of the blockage of the air preheater. It is more dif...

AI Technical Summary

Problems solved by technology

The heat sources of air heaters mainly include steam and waste heat of flue gas. Among them, the energy consumption of steam air heater is relatively high, which is unfavorable for improving the economic efficiency of the unit; while most of the air heaters with waste heat of flue gas are coupled with the waste heat recovery device of flue gas. It is lower than the steam heater, realizes the cascade utilization of flue gas waste heat, and has good economy, but the reliability of the flue gas waste heat heater is low, mainly due to the low reliability of the flue gas waste heat recovery device. When the flue gas waste heat recovery device fails, the air heater loses heat source and cannot operate

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