| Waste heat resource,that is surplus and abandoned energy and is from primary energy after conversion or processing,or discharged one after reaction in the industrial production process,belongs to the category of secondary energy.The waste and emission of various forms of waste heat in China have reached more than 50% of the total industrial energy consumption.The rational utilization of residual heat can help reduce the problems related to the global environment,such as greenhouse effect and the destruction of ozone layer by CFC.The enterprise has great potential to use waste heat reasonably,save energy and reduce emission,reduce production and manufacturing costs and improve the profit of the enterprise.The present thesis analyzed the current situation of waste heat utilization of some alcohol company production line,sorted out the residual heat source and residual heat which were not used effectively,determined the residual heat source and cold demand,and demonstrated the necessity of transformation.At the same time,according to the current situation of waste heat,combined with the operation of the alcohol fermentation production line,the overall process system planning was carried out,and it was put forward the transformation scheme of "using the heat released by the condensation of 130 ℃ finished wine gas to raise the condensed water from 68 ℃to 90 ℃,using 90 ℃ condensed water to drive the hot water lithium bromide refrigeration unit to prepare low-temperature chilled water for fermentation cooling".The process flow chart before and after the transformation was drawn.The process accounting and optimization of key equipment were carried out,and a heat exchanger with four-pass-fixed plate tube from stainless steel was selected.The calculated process parameters and equipment specifications were verified,and the transformation construction was investigated.Finally,the operation situation after the transformation was tracked,and the economic benefits were also calculated as well.The research results showed the steam condensate and the high temperature condensate from the wine gas heat exchange could be used as the heat source of driving power system with remaining heat for cooling,because it led the release of remaining heat and the cooling effect.The cold water produced by the condensed water was imported into the original cold water pipe network and the cold water tank.It is feasible for the selections of processing parameters and implementation plan.The application of one set of new heat exchangers and warm water refrigeration units caused the heat to be recovered inside the finished wine gas product.At the same time,the produced cold water was imported into the original cold water pipe network,which reduced the running time of electric refrigeration or lithium bromide absorption refrigerating machine,and realized the comprehensive utilization of waste heat.The waste heat load was 4145 k W,which could produce 4.0 million kcal/h cooling capacity(the efficiency of refrigerating machine was 1.1-1.2).After replacing the steam lithium bromide,the steam could be reduced by 5t/h.Based on the annual operation of 2880 h,the steam could be reduced by 14400 t,the steam tax free price was 161 Yuan/T,and the annual saving fee was 2.3184 million Yuan.It could reduce1356 tons of standard coal,922 tons of carbon dust,3380 tons of carbon dioxide,102 tons of sulfur dioxide and 51 tons of nitrogen oxides.The hot water used by the waste heat refrigerator could be used to crush and mix materials,so as to achieve the purpose of saving energy and reducing production cost. |
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