| At present,the iron and steel enterprises are generally equipped with waste heat generation system in the sintering process.But the generator set which goes into operation often does not reach the design load.On the one hand,the instability of the flue gas temperature produced by forced heat transfer during the cooling process.So the quality of the waste heat resource is not high.On the other hand,the problem of hot air leakage in flue gas recovery system has not been solved well all the time,resulting in the flue gas entering the boiler can not be satisfied with the demand of normal power generation.In this paper,a new sealing device is developed to improve the recovery of the hot air in the cooling machine by solving the problem of air leakage.Around this sealing technology,the retrofit scheme of cooling machine in waste heat recovery system is put forward by taking a steel sintering plant as an example.The specific contents of the study are as follows:(1)putting forward the design scheme of new type cooling machine sealing device.(1)Combined with the actual structure of the cooler,the design schemes of two kinds of sealing devices are put forward respectively.(2)The design scheme of upper seal is gravity type,extrusion type and elastic-pressure sealing device.(3)The design scheme of bottom seal is a new type of film brush composite sealing device.(2)Testing the performance of the new sealing device.(1)Design and build the cooling machine simulation test bench.The simulation and the analysis of the pressure inside the box on the test bench by using FLUENT software were carried out.The results show that the design scheme of the test bench meets the theoretical requirements.The pressure test for the completed test bench was carried out to ensure the uniformity of the pressure in the box.(2)A sample of an extruded seal device is made.The height of the steel brush is set to 100mm?150mm.Side-press bolt preload position is set to 1/2 and 2/3.By installing the sample on the test bench,the changes on pressure in the box are observed and optimum design values for extruded sealing devices are determined.The height of the steel brush should be 150 mm.The preload position of the side-press bolt is 1/2.(3)Production of a new type of membrane brush composite sealing device sample.The air leakage test was carried out at the site of a steel strip cooler.The air leakage loss of this part can be reduced by about 76% through the installation of the sealing device.After six months,the loss of air leakage was reduced by about 65%.(4)Preliminary study on the influence of sinter particle diameter and material layer height on the static pressure of the box.As the diameter of sinter particles becomes larger,the inlet dynamic pressure of the box becomes larger when the pressure in the chamber is stable at a fixed value.As the height of the sintered ore layer increases,the inlet dynamic pressure of the box becomes smaller.In contrast to the actual production conditions,the blast volume of the blower should be reasonably set up under different sintering conditions.In order to ensure the stability of the internal pressure of the trolley,as much as possible to save fan power consumption.(3)The retrofit scheme of waste heat recovery system for cooling machine is put forward.Around the proposed sealing technology,a retrofit scheme of waste heat recovery system for cooling machine is put forward by taking a steel sintering plant as an example.The scheme includes sealing technology with cooling machine,fan frequency conversion technology and boiler optimization technology.The sample was made for the field pilot-scale experiment.The feasibility and industrial value of the scheme are verified by combining the experimental results with the benefit analysis of the reconstruction scheme. |
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