CN206449670U - A kind of adjustable fume afterheat classification recovery system of heat - Google Patents

Abstract

The utility model discloses a heat-adjustable flue gas waste heat classification recovery system. The tail flue is divided into the left area flue gas channel and the right area flue gas channel by the vertical partition; the left area flue gas channel refers to the side close to the boiler combustion chamber and is arranged in the left area flue gas channel For the air preheater, in the flue gas channel in the right area, a high-temperature smoke-water heat exchanger is installed on the upper part of the flue gas channel in the right area, and a low-temperature smoke-water heat exchanger is installed in the lower part of the flue gas channel in the right area. Realize the hierarchical layout of the smoke-water heat exchanger of the low-temperature economizer; set an adjustable baffle on the top of the flue gas channel in the right area. The utility model can improve the utilization rate of waste heat recovery of the flue gas, increase the energy-saving effect of the low-temperature economizer, and improve the operation and adjustment of the equipment.

Description

A heat-adjustable flue gas waste heat graded recovery system

technical field

The utility model relates to a smoke exhaust system at the tail of a boiler, in particular to a heat-adjustable waste heat classification recovery system of flue gas.

Background technique

For coal-fired thermal power units, in the process of energy conversion, a large part of the calorific value of coal combustion is lost to the surrounding environment through exhaust smoke, and exhaust smoke loss is the largest item of boiler heat loss, accounting for about 60%-70%. The exhaust gas temperature is the main factor affecting this part of the loss. For every 10°C increase in the exhaust gas temperature, the exhaust gas loss will increase by about 0.6%-1%. At present, the exhaust gas temperature of thermal power unit boilers is generally relatively high, generally at 120°C-140°C. Recycling and utilizing this part of the waste heat of the flue gas to reduce exhaust loss is of great significance for improving unit economy and energy saving and emission reduction.

The conventional flue gas waste heat recovery system is to arrange a low-temperature economizer in the tail flue of the boiler, use the waste heat of the flue gas to heat the condensed water in the steam turbine recovery system, reduce the extraction steam of the recovery system, and return the saved steam to the steam turbine to continue to work. Increase output and improve unit efficiency.

In the framework of the traditional flue gas waste heat recovery system, the low-temperature economizer is arranged after the air preheater, and the temperature of the flue gas is limited by the outlet of the air preheater, generally not exceeding 140°C. The waste heat of the flue gas can only be used below the No. 6 low-pressure heater of the recuperation system, and the energy-saving effect is limited. At the same time, all the boiler exhaust smoke passes through the low-temperature economizer smoke-water heat exchanger. It is difficult to effectively adjust the residual heat of the flue gas used to heat the condensed water. Keep the system up and running. The throttling loss caused by waterway throttling increases the pressure loss of the pipeline, and the recirculation pipeline increases the complexity of the equipment and the difficulty of adjustment.

Utility model content

The utility model is to avoid the shortcomings of the above-mentioned prior art, and provides a heat-adjustable flue gas waste heat classification recovery system to improve the utilization rate of flue gas waste heat recovery, increase the energy-saving effect of low-temperature economizers, and improve equipment operation and adjust.

The utility model adopts following technical scheme for solving technical problems:

The structural features of the heat-adjustable flue gas waste heat classification recovery system of the utility model are: for the tail flue between the boiler economizer and the dust collector, the heat-adjustable flue gas waste heat recovery system is arranged. The tail flue is divided into a left area flue gas channel and a right area flue gas channel by a vertical partition; the left area flue gas channel refers to the side close to the boiler combustion chamber, and the left area flue gas channel An air preheater is arranged in the middle, and in the flue gas channel in the right area, a high-temperature smoke-water heat exchanger is installed on the upper part of the flue gas channel in the right area, and a low-temperature smoke-water heat exchanger is installed in the lower part of the flue gas channel in the right area The heat exchanger realizes the hierarchical arrangement of the smoke-water heat exchanger of the low-temperature economizer; an adjustable baffle is set on the top of the flue gas channel in the right area.

The structural feature of the heat-adjustable flue gas waste heat classification recovery system of the utility model is also that: the top end of the vertical partition is higher than the top end face of the air preheater, and the height difference is h, h=(1/5-1 /4) H, H is the height of the air preheater, the ratio of the width and height of the flue gas channel in the left area to the width of the flue gas channel in the right area is 3:2.

The structural feature of the heat-adjustable flue gas waste heat classification recovery system of the utility model is also that: the installation height of the adjustable baffle is 1-1.5m away from the top of the vertical partition, and the left end of the adjustable baffle is not more than vertical To the position of the partition, the adjustable baffle is an electric control baffle door, and its opening is linearly adjustable from 0° to 90°.

The structural feature of the heat-adjustable flue gas waste heat classification recovery system of the utility model is also that: the adjustable baffle is a louver-like structural form, which has a group of baffle blades respectively installed on the rotating shaft, and is passed through by an external connecting rod. The rotating shaft drives the baffle blades to interlock, so that each baffle blade rotates synchronously to realize the opening and closing of the adjustable baffle.

The structural feature of the heat-adjustable flue gas waste heat classification recovery system of the utility model is also that: the high-temperature smoke-water heat exchanger is arranged in parallel in the steam turbine water supply system, and the low-temperature smoke-water heat exchanger is arranged in parallel in the steam turbine condensation in the water system.

Compared with the prior art, the beneficial effects of the utility model are reflected in:

1. The utility model grades and recycles according to the energy grade. The low-grade energy is used to heat the condensed water, and the high-grade energy is used to heat the feed water, which greatly improves the waste heat recovery and utilization efficiency of the flue gas, increases the overall device efficiency and economy of the unit, and improves System energy saving effect;

2. In the utility model, the flue gas volume passing through the flue gas heat exchanger of the low-temperature economizer is controlled by the adjustable baffle, and the residual heat of the flue gas for heating the condensed water is adjusted to avoid throttling loss and The recirculation pipeline effectively reduces the complexity of the system and the difficulty of adjustment, and reduces the pressure loss of the water pipeline.

Description of drawings

Fig. 1 is the schematic diagram of the waste heat recovery system of flue gas at the boiler tail flue in the utility model;

Numbers in the figure: 1 tail flue, 2 adjustable baffle, 2a baffle blade, 2b rotating shaft, 3 vertical partition, 4 air preheater, 5 high-temperature smoke-water heat exchanger, 6 low-temperature smoke-water heat exchanger .

detailed description

Referring to Figure 1, the structural form of the flue gas waste heat recovery system with adjustable heat in this embodiment is: for the tail flue 1 between the boiler economizer and the dust collector, arrange the flue gas waste heat recovery with adjustable heat The system is to divide the tail flue 1 into the left area flue gas channel and the right area flue gas channel by the vertical partition 3; the left area flue gas channel refers to the side close to the boiler combustion chamber, and the left area flue gas channel The air preheater 4 is arranged in the gas channel, and in the flue gas channel in the right area, the low-temperature economizer and high-temperature flue-water heat exchanger 5 are arranged on the upper part of the flue gas channel in the right area, and the flue gas heat exchanger 5 in the right area The lower part of the low-temperature economizer low-temperature smoke-water heat exchanger 6 is set to realize the hierarchical arrangement of the low-temperature economizer smoke-water heat exchanger; an adjustable baffle 2 is set on the top of the flue gas channel in the right area. On the one hand, this structure ensures the heat required by the air preheater 4, and at the same time fully recovers the excess exhaust heat. Through the multi-stage arrangement of low-temperature economizers, the waste heat is used in stages, and the heat utilization efficiency is improved. Improve the efficiency of the unit device and increase the energy-saving effect; on the other hand, the recovered flue gas waste heat can be adjusted through the adjustable baffle 2 to ensure the safe, stable and energy-saving operation of the equipment under various working conditions of the unit.

In specific implementation, the corresponding structural settings also include:

Set the top of the vertical partition 3 higher than the top end of the air preheater 4, the height difference is h, h=(1/5-1/4)H, H is the height of the air preheater 4, according to the air preheater The ratio of the heat required for heating the air by the heater 4 to the total heat available for the exhaust of the boiler is to set the ratio of the width of the flue gas channel in the left area to the width of the flue gas channel in the right area as 3:2, which ensures that the air preheater 4 The required amount of flue gas can be fully recovered and utilized.

The installation height of the adjustable baffle 2 is 1‐1.5m from the top of the vertical partition 3, the left end of the adjustable baffle 2 does not exceed the position of the vertical partition 3, the adjustable baffle 2 electrically controls the baffle door, Its opening is 0°-90° linearly adjustable, and the adjustable baffle 2 is a louver-like structure, which has a set of baffle blades 2a respectively installed on the rotating shaft 2b, and the external connecting rod drives the baffle blades through the rotating shaft Linkage, so that each baffle blade rotates synchronously to realize the opening and closing of the adjustable baffle 2; when the baffle blade is vertical, the opening is the largest, and the amount of smoke entering the right channel area is the largest; when the baffle blade When it is horizontal, the opening is the smallest, and the amount of smoke entering the right channel area is the smallest.

In this embodiment, the high-temperature smoke-water heat exchanger 5 is arranged in parallel in the water supply system of the steam turbine. 6 are arranged in parallel in the condensate water system of the steam turbine, the inlet is introduced from the water inlet pipe of the low-pressure heater of the condensate water system, the outlet is connected to the outlet water pipe of the low-pressure heater, the high-temperature smoke-water heat exchanger 5 and the low-temperature smoke-water heat exchanger 6 The waterways are arranged in a reverse way, with bottom-in and top-out, in order to improve heat exchange efficiency.

working principle:

The unit boiler exhaust smoke enters the left and right flue gas passages divided by the vertical partition 3 from the tail flue, and the flue gas entering the left area flue gas passage passes through the air preheater 4 to heat the air required for boiler fuel combustion. The flue gas entering the flue gas channel in the right area first enters the high-temperature flue-water heat exchanger 5 of the low-temperature economizer to heat the feed water introduced from the steam turbine system. After the heat exchange is completed, it continues to enter the low-temperature economizer low-temperature flue-water heat exchanger 6 for heating The condensed water is introduced from the steam turbine system, and the feed water and condensed water are heated and returned to the steam turbine system. After the heated feed water and condensed water return to the steam turbine, they will squeeze out the corresponding part of the extraction steam in the heat recovery system, and this part of the extracted steam will return to the steam turbine to continue to work. , increase the output of the unit and the efficiency of the device, and realize the hierarchical recycling of exhaust smoke. As the working condition of the unit and the external environment change, the amount of flue gas required by the low-temperature economizer of the flue gas channel in the right area is also different. The flue gas entering the flue gas channel in the right area is controlled through the adjustable baffle 2 according to the equipment parameters. The amount is adjusted and controlled, and the adjustable baffle 2 is linearly adjusted by the electric control baffle door opening. After the exhaust gas from the air preheater 4, the high-temperature smoke-water heat exchanger 5, and the low-temperature smoke-water heat exchanger 6 completes the heat exchange, the temperature of the flue gas is greatly reduced, and enters the dust collector for dust removal.

Claims (5)

1. a kind of adjustable fume afterheat classification recovery system of heat, it is characterized in that：For being in boiler economizer and deduster Between back-end ductwork (1), arrange the adjustable flue gas waste heat recovery system of heat, be by the back-end ductwork (1) by vertically every Plate (3) is divided into left field exhaust gases passes and right side area exhaust gases passes；The left field exhaust gases passes fire close to boiler Room side is burnt, air preheater (4) is arranged in the left field exhaust gases passes, in the right side area exhaust gases passes, The top for being in right side area exhaust gases passes sets high temperature cigarette water- to-water heat exchanger (5), and the bottom for being in right side area exhaust gases passes is set Warm cigarette water- to-water heat exchanger (6) is set low, the hierarchical arrangement of low-level (stack-gas) economizer cigarette water- to-water heat exchanger is realized；In the right side area exhaust gases passes Top set fender plate (2).

2. the adjustable fume afterheat classification recovery system of heat according to claim 1, it is characterized in that：The vertical baffle (3) top is higher than the top end face of air preheater (4), and difference in height is h, and h=(1/5-1/4) H, H is air preheater (4) Height, the left field exhaust gases passes it is wide it is high the ratio between with right side area exhaust gases passes width be 3：2.

3. the adjustable fume afterheat classification recovery system of heat according to claim 1, it is characterized in that：The fender plate (2) setting height(from bottom) is apart from the top 1-1.5m of vertical baffle (3), and the left position of fender plate (2) is no more than vertical baffle (3) position, the fender plate (2) is Electronic control baffle door, and its aperture is 0 ° -90 ° linear adjustable.

4. the adjustable fume afterheat classification recovery system of heat according to claim 3, it is characterized in that：The fender plate (2) it is the structure type of venetian blind type, with one group of baffle blades being separately mounted in rotating shaft, rotating shaft is passed through by outer link Baffle blades linkage is driven, makes each baffle blades synchronous axial system, realizes the keying of fender plate (2).

5. the adjustable fume afterheat classification recovery system of heat according to claim 1, it is characterized in that：By the high temperature cigarette Water- to-water heat exchanger (5) is arranged in parallel in steam turbine water supply system, and the low temperature cigarette water- to-water heat exchanger (6) is arranged in parallel in steam turbine In condensate system.