带有沼液热回收的沼-电-热泵模式研究-供热、供燃气、通风及空调工程专业论文.docxVIP

哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 哈尔滨工业大学工学硕士学位论文 - - PAGE IV - - - PAGE III- Abstract China’s northern winter is cold,dry and long,low temperatures resulted in lower temperature of digester tank,low gas tank production rate,annual operating time short,system efficiency poor,is not conducive to the promotion of biogas systems.For this phenomenon, proposing a new model of the marsh-electricity-heat energy self-sufficiency based biogas systems, using waste heat recovery to heat the feed slurry and replenishment heat integrated biogas power generation, make way to achieve full self-sufficiency in energy. Guarantee feed temperature compliance, efficiency and stable operation in the winter. For the characteristics of the vegetable and livestock of winter heating required to cold regions, the system also comes with heating function. The energy of the gas system analysis shows that the systems main heat loss from the discharge slurry. But slurry is not a common working fluid flow of heat transfer, to design and calculation correctly of slurry waste heat recovery heat exchanger，though experimental determination，the paper gets slurry density, thermal conductivity, heat capacity and other physical parameters，in addition to the value of PH, solid content, particle size distribution of suspended solids and other parameters ， identification of the slurry rheological properties,the constitutive equation obtained，and derive the slurry pipe flow with the velocity and temperature field, and its associated guidelines for heat exchanger tube in the formula. The paper sees annual cost as the objective function, to optimized design the various components of the composition and operating parameters, evaluate energy efficiency, economic and environmental benefits of the whole system. Shows that the system can indeed the efficient operation of biogas digesters in the winter, achieve energy self-sufficiencyof and the heating capacity. Th