Zhangjiagang HuaDong Boiler Co., Ltd.
Zhangjiagang HuaDong Boiler Co., Ltd.
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Boiler Parts Carbon Steel Boiler Economizer for Thermal Power Plant Coal-fired Boilers
Product Description
| 1 | Working principle of a flue-gases cooler is the same as in the above-described equipment, but the aim in this case is to cool a primary fluid, not to get a thermal profit by heating a secondary fluid. |
| 2 | These equipment are usually installed as the previous step to a flue-gases cleaning, to avoid the gases from reaching the cleaning systems at too high temperatures. This means an alternative to the dilution with air, which would imply an over-sizing of the mentioned systems. |
Details
| 1 | Before designing this kind of equipment, it is necessary to know the nature of the gases to be cooled and their dust content. |
| 2 | The purpose of all that is to design an equipment free of important fouling which would force to make cleaning works more frequently than wanted. |
| 3 | We must have in mind as well the availability to detach the dust from the gaseous stream containing it in all those areas where there is a bend or some enlarging in the pass section, which forces to include in the design some systems for dust collection and removal, to allow the correct heat exchange. |
Conclusion
To sum up, the following items have to be taken into account when designing a flue-gases cooler:
| 1 | Kind of fluid. |
| 2 | Dust content. |
| 3 | Maintenance and cleaning works. |
| 4 | Connection of the equipment with the rest of the plant. |
| 5 | Depending on the above mentioned factors, different technical solutions may be applied which will go through the adoption of an arrangement: |
| 6 | Vertical/Horizontal. |
| 7 | Modular (with only one or many fans). One or more steps. |
Efficiency
| 1 | Flue gas condensation may cause the heat recovered to exceed the Lower Heating Value of the input fuel, and thus an efficiency greater than 100%. |
| 2 | Since historically most combustion processes have not condensed the fuel, usual efficiency calculations assume the combustion products are not condensed. |
| 3 | This assumption is implicit when basing calculations on the Lower Heating Value. |
| 4 | A more rigorous approach would be to base efficiency calculations on the Higher Heating Value, which typically results in efficiencies less than 100%. |
| 5 | Should the flue gases be cooled below 25 °C (77 °F), even efficiencies based on the Higher Heating Value may exceed 100%, since typical heating value definitions assume that all heat is released when combustion products are cooled to somewhere between 15.56 °C (60.01 °F) and 25 °C (77 °F). |
Design principle
When the designer's choice is the multi-cyclone collector,or the electrostatic precipitator,or a different type constructed of metals or ther low temperature materials,it becomes necessary to add a gas-cooling device.This is done to assure that he entering flue gases are with in the temperature range of 600 to 700F,with no possibility of even flashes of higher temperatures.
The exit temperature depends upon the materials used downstream from the cooling chamber.Since , however , experience and economical evaluations justifying the use of the high temperature alloys are not generally available this paper is based upon the exit temperatures stated above.
The two agents commonly used as cooling materials are air and water.Both have advantages and disadvantages.Generally,a combination of the two is found most acceptable.However,they must first be considered separately,so that the characteristics of each may be properly evaluated.
Whole set product picture
