Effects of charcoal production on maize yield,chemical properties and texture of soil   总被引：4，自引：0，他引：4  

Philip?G.?OguntundeEmail author  Matthias?Fosu  Ayodele?E.?Ajayi  Nick?van de?Giesen 《Biology and Fertility of Soils》2004,39(4):295-299

The effects of charcoal production on soil textural and chemical properties were investigated in Ejura, Ghana. The aim was to study the effects of heating and charcoal residue on maize yield, soil texture and soil chemical properties. Composite samples were taken from the 0–10 cm layer of soil at charcoal-making sites and from adjacent fields (control). Twelve sites were randomly selected for the study across the range of the Kotokosu watershed. Maize was planted in four selected locations on charcoal site soils (CSS) and adjacent field soils (AFS) to assess the impact of charcoal production on crop yield. There was a significant increase in soil pH, base saturation, electrical conductivity, exchangeable Ca, Mg, K, Na and available P in the soil at the kiln sites as compared to the adjacent soils. A relative change of up to 329% was observed in K while organic C and total N decreased by 9.8% and 12.8%, respectively. Organic C and total N were highly correlated ( P <0.01) and both parameters significantly ( P <0.05) depended on clay minerals in the soils. Soil texture was also modified with a significantly higher sand content and lower clay fraction in the CSS. The grain and biomass yield of maize increased by 91% and 44%, respectively, on CSS as compared to AFS. Further research to ascertain the long-term effects of charcoal production on the soil environment and the fertility of tropical soils is needed.  相似文献   

欧姆加热过程中苹果浆的电导率及VC降解规律研究     

郭芳  赵武奇  尹贻童  夏鑫淼 《农产品加工．学刊》2011,(6):26-30

研究了苹果浆的欧姆加热规律及VC的降解动力学,考察了温度和果浆含量对电导率的影响以及电场强度、果浆含量对加热速率的影响。结果表明,苹果浆的电导率随温度的升高而增大,且呈线性关系;随着果浆含量的增加,电导率和加热速率都在增加;随着电场强度的增大,加热速率增加。苹果浆中VC对热不稳定,苹果浆中VC降解符合动力学一级反应,得到的苹果浆中VC的预测模型,经验证与实测值拟合较好,表明该模型是合理的。  相似文献   

Heat Transfer Performance of Capillary Mats Using Wet Construction in Winter     

YANG Jie  ZHOU Hui xin  ZHANG Xu  LIU Yan  WANG Jun 《保鲜与加工》2011,(2):80-85

For the capillary mats using wet construction, a winter experiment designed to investigate the heat transfer performance was described, and the heat transfer performance analysis which contains the comparisons between different pipe space and different thickness of cement mortar surface was carried out. As a result, compared with that of the traditional radiant heating pipes, the capillary mats of wet construction require supply water with lower temperature, and it shows good heat transfer performance and system energy efficiency as well. According to the demand of indoor heat dissipation and human comfort as well as the coupling relationship between the temperature of supply water and surface construction thickness, it is suggested that the proper construction method should be comprehensively considered in practical applications.  相似文献   

Heating performance analysis of multi-nozzle water-jet steam ejector     

TONG Ming wei  CAI Qin  BAI Xiu juan 《保鲜与加工》2011,(6):60-63

Abstract:This paper developes a heating coefficient model to study the heating performance of multi-nozzle water-jet steam ejector. It analyzes the factors of heating performance, and explores the relationships between the heating performance and different operating parameters theoretically and experimentally. The results show that the heating performance of multi-nozzle water-jet steam ejector is very good. The heating coefficient decreases with the increase of the inlet water temperature, and increases with the increase of the steam pressure and ejecting coefficient. The relationships between heating performance of ejector and different operating parameters by calculation and experiment are in good agreement.  相似文献   

太阳能加热输送原油系统应用研究   总被引：12，自引：0，他引：12  

王学生  王如竹  吴静怡  许煜雄 《油气储运》2004,23(7):41-45

凝点高、粘度大的原油在输送过程中必须进行加热与保温,以保持原油的良好流动性,用太阳能替代部分常规能源来加热输送原油可以减少大量的能源消耗.根据原油加热输送过程的工艺条件及特点,设计了一套太阳能加热原油输送系统,介绍了该系统的设计原理和性能指标,应用表明,该系统可以使原油温度提高25～30℃,年均节省天然气9×104m3.  相似文献   

加热对牛奶中风味物质的影响   总被引：4，自引：0，他引：4  

杨楠  张兰威 《东北农业大学学报》2007,38(1):39-43

试验用有机溶剂乙醚萃取了原料乳和巴氏杀菌乳中的风味物质,并用气相色谱(GC)-质谱(MS)联用法结合内标法对其进行定性和相对定量分析。结果表明,在原料乳的风味物质中,共鉴定出46种物质,主要由C_8～C_(20)的酮类、烷烃、烷酸和酯类组成;在加热温度为65℃时间为30 min的巴氏杀菌乳中,共鉴定出69种物质,除上述几类物质外还含有醛类、酯类和烯类等物质。其中辛烷、环氧乙烷、己酸、苯乙酮、壬醛、辛酸、十二烷、2-癸醛、十三烷、2,4(E)(E)-十二烯醛、2-亚甲基-环戊醇、癸酸等具有较强的挥发性,是牛乳中风味物质中的重要成分。  相似文献   

掺混法在燃气热值调整中的应用   总被引：1，自引：0，他引：1  

刘春杨  许晖  宋素合  曹雄 《油气储运》2007,26(6):59-61

为解决管输天然气热值高于城市燃气所需热值的问题,达到经济、合理、充分的利用天然气的目的,提出采用投资少的掺混法调整LNG热值,并且从配置方式、工艺流程、调节原理和设置气态的天然气或空气混合装置等方面对掺混法工艺流程和控制方案进行了研究分析,阐明了掺混法在LNG热值调整中应用的可行性。  相似文献   

模糊控制技术在太阳热水系统工程中的应用     

马敏  雷廷宙  王磊  高林朝  张炜宇 《河南农业大学学报》2003,37(2):192-195,204

介绍了太阳热水系统工程的基本组成及特点，详细阐述了采用PIC系列单片机和模糊逻辑控制算法实现水温恒定控制的基本原理、电路设计、精确量的模糊化、模糊控制规则以及测控软件的编制。  相似文献   

利用热管换热器回收加热炉排烟余热   总被引：1，自引：0，他引：1  

钱成文 《油气储运》1997,(5)

对改进的两相半开式热管换热器的工作原理及热管换热器换热效率的计算方法作了介绍,并列举了三种热管换热器的应用实例。指出热管换热器具有传热效率高、压力损失小、结构紧凑、应用范围广、维修费用少等优点,同时也存在酸露点的低温腐蚀等实际问题,在使用中不断加以改进,为回收各种加热设备的排烟余热、节约能源,发挥它的巨大作用。  相似文献   

5000KW微机控制直接式原油加热炉     

姜维刚 《油气储运》1994,13(6):24-30

加热炉是长输管道和油田生产中广泛使用的加热设备，要求热效率高、安全可靠、适应性广、性能稳定、操作简便。综述了加热炉技术的发展状况，介绍了５０００ＫＷ微机控制直接式原油加热炉的性能，特点和研制，测试、运行结果。该加热记已正式投入生产运行一年多，与相同热负荷的热煤间接加热，造价为后者的６０％－７０％，占地面积也大为减少，以濮临线输油量计算，年节约燃料油费用人民币１００万元，１９９３年１２月通过了中国石  相似文献