CN203431900U - Smoke cooling and air heating device of power station boiler - Google Patents

Abstract

The utility model discloses a cold smoke heating device for a boiler in a power station, which comprises a flue gas cooler, a water pump, a water tank and an air heater sequentially connected through pipes, the flue gas cooler is also connected with the heater, and the water pump and the flue gas are cooled. There is a flow meter on the pipeline of the device. The pipeline is provided with a circulating medium with an operating temperature of 65-96° C. and an operating pressure of 0.05-0.2 MPa. The water tank is provided with a supplementary discharge port. The pipelines are all provided with adjustable valves. The circulating medium uses demineralized water from the power plant. The device recovers part of the heat from the exhaust smoke of the boiler, and the air supplied by the heating boiler returns to the boiler combustion device. While reducing the exhaust gas temperature and improving the thermal efficiency of the boiler, it also increases the inlet cold air temperature of the boiler air preheater, avoids low-temperature corrosion of the heating surface at the rear of the power plant boiler, and improves the safety of boiler operation. Since the circulating medium operates within a certain temperature range, the temperature of the outer wall of the flue gas cooler is always higher than the dew point of the flue gas, effectively avoiding low-temperature corrosion of the flue gas cooler.

Description

Power station boiler cold smoke heating device

technical field

The utility model relates to the technical field of thermal power generation, in particular to a cold smoke and warm air device for a boiler in a power station.

Background technique

At present, it is common to imagine that the exhaust gas temperature of power plant boilers is higher than the design value. Severe exhaust gas temperature overheating not only affects the economics of the power plant, but also affects the safe operation of the air preheater, dust collector and subsequent desulfurization equipment. Therefore, reducing the exhaust gas temperature has important practical significance for energy saving and consumption reduction, and improving the safety and reliability of boilers; at the same time, due to the shortage of energy sources, the quality of coal used by power plant boilers generally declines, especially the sulfur content of raw coal is generally higher than that of the designed coal type. content, resulting in very serious low-temperature corrosion of the heating surface at the tail of the power plant boiler, and even affecting the safe operation of the power plant boiler, so it is urgent to prevent low-temperature corrosion.

In view of the above two problems, the existing technology cannot achieve both:

Such as low-pressure economizer technology, low-pressure economizer technology is a low-pressure exhaust device that recovers part of the heat exhausted by power plant boilers and sends it to the thermal device of the power plant, which can effectively reduce the exhaust gas temperature, because the recovered heat does not return to the combustion device , so the thermal efficiency of the boiler does not change; the heat enters the low-pressure air extraction device, and since the thermoelectric conversion efficiency of low-pressure steam is less than 25%, most of this part of heat enters the steam turbine condenser of the power plant and is discharged.

Another example is various air heaters, which can increase the inlet air temperature of the boiler air preheater and effectively avoid low-temperature corrosion of the heating surface at the boiler tail. increase, reduce the boiler economy, and affect the safe operation of the air preheater, dust collector and subsequent desulfurization equipment. In addition, because the heat energy for heating the air heater comes from the heat source of the plant (such as auxiliary steam) outside the boiler device, this The heat source of the plant is initially generated by the combustion of the boiler. Considering the transmission and conversion efficiency, it is impossible to be 100%, so the economy is poor.

Utility model content

The purpose of this utility model is to solve the above problems and provide a cold smoke and warm air device for a power station boiler. The cold air temperature at the inlet of the air preheater effectively avoids the advantages of low-temperature corrosion of the heating surface at the rear of the boiler.

In order to achieve the above object, the utility model adopts the following technical solutions:

A power plant boiler cold smoke heating device, including a flue gas cooler, a water pump, a water tank and an air heater connected in sequence through pipelines, the flue gas cooler is also connected to the heater, the water pump is connected to the flue gas cooler There is a flow meter on the pipeline.

The pipeline is provided with a circulating medium with an operating temperature of 65-96° C. and an operating pressure of 0.05-0.2 MPa.

The water tank is provided with a supplementary discharge port.

The pipelines are all provided with adjustable valves.

The circulating medium uses demineralized water from the power plant.

Working principle of the utility model:

In the working process, the desalted water of the power plant is pressurized by the water pump and enters the flue gas cooler, the cooled flue gas absorbs heat and then enters the heater, and the heated air returns to the water tank after the air is released. By adjusting the flow rate to adjust the working temperature of the circulating medium, the flow rate adjustment can be adjusted by the speed of the water pump or by an adjustable valve. The operating temperature of the circulating medium is 65-96°C, and the operating pressure is 0.05-0.2MPa (gauge pressure).

The device can lower the exhaust gas temperature of the utility boiler by 25-45°C, increase the air supply degree by 30-50°C, and increase the boiler efficiency by 1.3-2.0%. Based on the current average power supply coal consumption of 300MW units is 334 g/kW.h, it can save 4-6 g/kW.h of standard coal. If the unit runs for 6,000 hours a year and the standard coal price is 800 yuan/ton, the annual savings will be more than 7 million yuan, twice that of the low-pressure economizer.

The beneficial effects of the utility model:

1. The device is simple, the initial investment is small, and the investment recovery period is short. The operating pressure of the device is low, and the requirements for materials are low;

2 There is a replenishment and discharge port, and the device is easy to start and stop for maintenance;

3 The device reserves a heating outlet, which is convenient and quick to connect with the heating device;

4 Carry out overall planning and consideration, not only make full use of the recovered heat, improve boiler efficiency, reduce coal consumption, but also increase the inlet cold air temperature of the air preheater of the power plant boiler, effectively avoiding low-temperature corrosion of the heating surface of the boiler tail.

5. The specific operating temperature can be determined according to the sulfur content of the coal used by the power plant boiler to ensure that the temperature of the outer wall of the flue gas cooler is not lower than the dew point of the flue gas. Maintain a certain pressure of the circulating medium to ensure that the circulating medium does not boil in the flue gas cooler and ensure the heat exchange effect.

6 Contains a combination device of flue gas cooler and air heater, which can recover and make full use of part of the heat exhausted by the power plant boiler, and return the air supplied by the heating boiler to the combustion device, saving coal and improving the thermal efficiency of the power plant boiler. At the same time, Since the inlet cold air temperature of the boiler air preheater is increased, the low-temperature corrosion of the heating surface at the rear of the utility boiler can be effectively avoided.

7. The demineralized water of the power plant is used as the circulating medium, which can effectively prevent the scaling and corrosion of the flue gas cooler, heater and pipeline.

Description of drawings

Fig. 1 is the device connection schematic diagram of the present utility model;

Among them, 1. Flue gas cooler, 2. Flow meter, 3. Water pump, 4. Water tank, 5. Air heater, 6. Adjustable valve.

Detailed ways

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

As shown in Figure 1, a cold smoke and warm air device for a utility boiler includes a flue gas cooler 1, a water pump 3, a water tank 4 and a heater 5 connected in sequence through pipelines, and the flue gas cooler 1 is also connected with the warm air The water pump 3 is connected to the gas cooler 1, and a flow meter 2 is provided on the pipeline of the water pump 3 and the flue gas cooler 1.

The pipeline is provided with a circulating medium with an operating temperature of 65-96° C. and an operating pressure of 0.05-0.2 MPa.

The water tank 4 is provided with a supplementary discharge port.

The pipelines are all provided with adjustable valves 6 .

Although the specific implementation of the utility model has been described above in conjunction with the accompanying drawings, it does not limit the protection scope of the utility model. Those skilled in the art should understand that on the basis of the technical solution of the utility model, those skilled in the art do not need to Various modifications or deformations that can be made with creative efforts are still within the protection scope of the present utility model.

Claims (4)

1. A power station boiler cold smoke heating device, characterized in that it comprises a flue gas cooler, a water pump, a water tank and an air heater connected in sequence through pipelines, and the flue gas cooler is also connected with the air heater, and the Flow meters are installed on the pipes of the water pump and the flue gas cooler. 2 . The cold smoke heating device for power plant boilers according to claim 1 , wherein a circulating medium with an operating temperature of 65-96° C. and an operating pressure of 0.05-0.2 MPa is provided in the pipeline. 3. A cold smoke heating device for power plant boilers as claimed in claim 1, characterized in that, the water tank is provided with a supplementary discharge port. 4. A cold smoke heating device for power plant boilers as claimed in claim 1, wherein said pipelines are provided with adjustable valves.

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