太阳能—热泵联合干燥小麦的系统研究与设计

发布时间：2018-03-06 14:31

本文选题：太阳能干燥　切入点：热泵干燥　出处：《山东农业大学》2016年硕士论文　论文类型：学位论文

【摘要】：我国是农业大国,是世界上最大的粮食生产国与消费国,但同时也是粮食损失率最高的国家之一。据统计每年我国粮食在收获后损失高达15%,其中因干燥不及时而损失的粮食占5%。我国粮食种植比较分散,传统的自然晾晒又受天气的影响,所以寻找一种行之有效的干燥方式是本文出发点。传统的干燥作业是一项高能耗的工艺过程,我国每年因干燥所耗能源占国民经济总能耗的12%左右。太阳能是一种清洁的可再生能源,人们逐步开始了对太阳能在干燥作业上的研究与推广。热泵干燥装置具有节能、安全和环保等优点。太阳能干燥与热泵干燥通过有机结合共同作业,不仅能够节能减排,还能克服两者缺点,提高干燥品质。本文基于前人对太阳能热泵联合干燥的理论基础研究设计了一套由光伏发电系统供电,太阳能热泵联合干燥粮食的系统。该系统热源有两个,一个是太阳辐射对空气的加热;一个是热泵消耗电能加热空气。其中热泵所需电能来自光伏发电系统所发电量,在晴天状况下可以满足整个干燥作业的电量消耗。在夜晚或遇到阴雨天气时,系统可以通过消耗电网电量完成干燥作业,减少排放物对环境的污染。基于热力学第一定律及光伏设计标准,完成了对干燥装置以及光伏发电组件的设计与选型。为方便对干燥进度的实时监测,我们安装了温湿度变送器,通过与上位机的连接完成对干燥数据的收集。在晴天与阴天下,我们选用小麦为试验材料分别进行有、无太阳能的热泵干燥性能试验。通过5小时的干燥结果分析,说明了太阳能对干燥系统的作用明显,能够加快干燥速率,缩短干燥时间,并且节省大量的能源。在晴天光照状况较好的天气状况下,系统的制热系数COP能够达到2.4。而COP大于2就能超过蒸汽锅炉的供热效率,数据表明这套系统一定情况下可取代锅炉作为干燥作业的供热源。太阳能光伏发电系统能够持续发电,在不进行干燥作业时,电量可以直接并入国家电网,缓解供电压力,还能得到经济回报。按照我国对光伏发电产业的扶持政策,在5-6年即可回收成本,经济推广价值较高。
[Abstract]:China is a large agricultural country and the largest food producer and consumer in the world. But at the same time, it is also one of the countries with the highest grain loss rate. According to statistics, the annual loss of grain after harvest in our country is as high as 15 percent, of which 5percent of the grain lost because of untimely drying. Grain cultivation in our country is relatively scattered. The traditional natural drying is affected by the weather, so finding an effective drying method is the starting point of this paper. The traditional drying process is a high energy consumption process. The energy consumption due to drying accounts for about 12% of the total energy consumption in China every year. Solar energy is a clean renewable energy. People have gradually begun to study and popularize solar energy in drying operations. Heat pump drying device has energy saving. The combination of solar drying and heat pump drying can not only save energy and reduce emissions, but also overcome the shortcomings of both. In this paper, based on the previous theoretical basis of solar heat pump combined drying, a solar energy heat pump combined drying system, which is powered by photovoltaic power system, is designed. There are two heat sources in the system. One is the heating of air by solar radiation, the other is that heat pumps consume electricity to heat air. Under the condition of sunny weather, the power consumption of the whole drying operation can be satisfied. At night or in rainy weather, the system can complete the drying operation by consuming the electric power of the power grid. Based on the first law of thermodynamics and the design standard of photovoltaic, the design and selection of drying device and photovoltaic power generation module are completed. In order to facilitate the real-time monitoring of drying progress, We installed a temperature and humidity transmitter to collect dry data by connecting to the upper computer. In sunny and cloudy weather, we selected wheat as the test material. Heat pump drying performance test without solar energy. Through the analysis of drying results in 5 hours, it is proved that solar energy has obvious effect on drying system, which can speed up drying rate and shorten drying time. And save a lot of energy. In the sunny weather condition, the heating coefficient COP of the system can reach 2.4. However, if the COP is larger than 2, the heating efficiency of the steam boiler can be exceeded. The data show that the system can replace boiler as heating source for drying operation under certain circumstances. Solar photovoltaic power generation system can continuously generate electricity. Without drying operation, the electricity can be directly integrated into the state grid to relieve the power supply pressure. According to the policy of supporting photovoltaic power generation industry in China, the cost can be recovered in 5-6 years, and the value of economic promotion is high.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S226.6

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