CN202195502U - Constant-temperature starting type air pre-heater - Google Patents

Abstract

A constant temperature start-up air preheater is characterized in that it is composed of a hot air pipe and a cold air pipe connected together through a partition, and the heat pipe running through the hot air pipe, the partition and the cold air pipe is formed by the evaporation section located in the hot air pipe It is composed of a condensing section located in the cold air pipe. The heat pipe is a constant-temperature start-up heat pipe. When the exhaust gas temperature is higher than the preset temperature of the constant temperature start-up element, it will start to start heat exchange.

Description

Constant temperature start air preheater

technical field

The utility model relates to a constant temperature starting type air preheater.

Background technique

The rotary air preheater is a facility in a thermal power plant and is used for heat exchange between flue gas and air.

The rotary air preheater is a flue gas end heat exchange device commonly used on large boilers in power plants. Compared with the tubular air preheater, the rotary air preheater has a compact structure, small volume, and high heat transfer surface density. , the whole machine is light in weight, less metal consumption, easy to install and arrange, and the low-temperature corrosion is lighter than the tubular heat exchanger. It is suitable for use on large boilers, but the disadvantage of the rotary air preheater is that the air leakage is large, When the working condition is good, it is 6% to 8%, and when the seal is bad, it is 20% to 30%. In addition, the structure of the rotary air preheater is complicated, the manufacturing process and installation requirements are high, the operation and maintenance workload is large, and the automatic control of the thermal state is also relatively difficult. Higher air leakage causes the air pressure at the inlet of the preheater to decrease, the fan current to increase, the excess air coefficient behind the preheater to increase, the exhaust gas temperature at the tail to decrease, the thermal efficiency of the boiler to decrease, and the coal loss to increase. load.

Utility model content

The utility model relates to a constant temperature start-up air preheater, which is used as the final air preheater of a large thermal power boiler, that is, to replace the commonly used rotary air preheater, and can accurately control the exhaust gas temperature, and the exhaust gas temperature does not follow the work. Circumstances change.

The technical scheme of the utility model is as follows: a constant temperature start-up air preheater, which is composed of a hot air pipe and a cold air pipe connected together through a partition, and is characterized in that The heat pipe is composed of an evaporating section located in the hot air pipe and a condensing section located in the cold air pipe. The heat pipe is a constant-temperature start-up heat pipe, and the start-up temperature for the heat pipe to start heat exchange is preset in the constant-temperature start-up heat pipe.

The utility model has the following advantages:

A. This kind of heat pipe with constant temperature function is installed in the air preheater. It does not exchange heat under the preset temperature. It starts only when the exhaust gas temperature is higher than the preset temperature of the constant temperature start-up element. Perform heat exchange. In this way, the exhaust gas temperature of the boiler can be guaranteed to be a constant value, which will not fluctuate with the fluctuation of the boiler working condition.

B. The inner wall of the heat pipe is lined with copper foil, making the heat pipe a long-life heat pipe that is "incompatible with molten steel", which can ensure the life of the air preheater for up to 20 years.

C. Fully meet the functional requirements of thermal power boilers for air preheaters. The air preheater with constant temperature function does not rotate, so there is no air leakage problem of the rotary air preheater. It can reduce the coal consumption of power generation and reduce the power consumption of the induced draft fan. Using the air preheater with constant temperature function, the exhaust gas temperature can be precisely controlled, and the exhaust gas temperature does not change with the change of working conditions. Utilizing this feature, the exhaust gas temperature of the thermal power boiler can be designed to be about 15°C lower, which can increase the boiler efficiency by more than 1%, without encountering dew point corrosion problems under special working conditions.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Further explanation in conjunction with accompanying drawing:

This constant temperature start-up air preheater is composed of a hot air pipe 1 for flowing high-temperature flue gas, a cold air pipe 2 for flowing air, and a partition 3. Type heat pipe 4 is made up of evaporating section 6 located in the hot air pipe and condensing section 5 located in the cold air pipe. This heat pipe is a constant temperature start heat pipe.

Compared with the existing rotary air preheater, the air preheater with constant temperature function of the utility model:

The energy-saving effect of using the air preheater with constant temperature function of the utility model:

According to the rough judgment above, the efficiency of the boiler can be increased by about 1.5%.

Claims (2)

1. A constant temperature starting type air preheater is characterized in that it is made up of a hot blast pipe and a cold blast pipe connected together by a partition, and the heat pipe running through the hot blast pipe, the partition and the cold blast pipe is formed by a The evaporating section and the condensing section located in the cold air pipe are composed, and the heat pipe is a constant-temperature start-up heat pipe, and the start-up temperature for the heat pipe to start heat exchange is preset in the constant-temperature start-up heat pipe. 2. The constant temperature start-up air preheater according to claim 1, characterized in that the inner wall of the heat pipe is lined with copper foil.

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