Pub Date : 2015-01-15DOI: 10.7699/J.YNNU.NS-2015-003
Xiao-fang Hu, W. Gao, Tao Liu, Wenxian Lin
In this study, the flow of the fluid in the nozzle status were analyzed in detail. The results indicated that the changing rule of the nozzle cross section not only depends on the change situation of the velocity of flow, but also related to other state parameters, especially the Mach number. Finally, the correctness of the simulation and the feasibility of numerical simulation in practical engineering were proved by comparing the simulation of laval nozzle with the theoretical analysis of it.
{"title":"Fluid Flow Situation in the Nozzle of the Theoretical Analysis and Numerical Simulation","authors":"Xiao-fang Hu, W. Gao, Tao Liu, Wenxian Lin","doi":"10.7699/J.YNNU.NS-2015-003","DOIUrl":"https://doi.org/10.7699/J.YNNU.NS-2015-003","url":null,"abstract":"In this study, the flow of the fluid in the nozzle status were analyzed in detail. The results indicated that the changing rule of the nozzle cross section not only depends on the change situation of the velocity of flow, but also related to other state parameters, especially the Mach number. Finally, the correctness of the simulation and the feasibility of numerical simulation in practical engineering were proved by comparing the simulation of laval nozzle with the theoretical analysis of it.","PeriodicalId":17502,"journal":{"name":"Journal of Yunnan Normal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75841845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7699/J.YNNU.NS-2014-006
Ren-fei Li, W. Gao, Tao Liu, Wenxian Lin
Q17，daily solar heat gain corresponding to 17MJ／m2 of daily collectible radiation is one of key parameters to evaluate the thermal performance of a solar water heater．In this paper, the influence of daily collectible radiation on the daily heat gain of an evacuated tube solar water heater is studied experimentally in the radiation condition described in GB／T 18708. Results showed that the daily heat gain linearly increases with the increase of daily colllectible radiation, but Q17 and system's efficiency coefficient almost kept constant. It was also found that when the testing condition with the daily coUectible radiations being not less than 17 MJ／m2 changed into that of not less than 16 MJ/m2，change of Q17 and the system's energy efficiency coefficient was not insignificant, implying that the testing conditions about daily collectible radiation specified in the revised version of GB／T19141 was reasonable.
{"title":"The influence of daily radiation collected on the daily heat gain of an evacuated tube solar water heater","authors":"Ren-fei Li, W. Gao, Tao Liu, Wenxian Lin","doi":"10.7699/J.YNNU.NS-2014-006","DOIUrl":"https://doi.org/10.7699/J.YNNU.NS-2014-006","url":null,"abstract":"Q17，daily solar heat gain corresponding to 17MJ／m2 of daily collectible radiation is one of key parameters to evaluate the thermal performance of a solar water heater．In this paper, the influence of daily collectible radiation on the daily heat gain of an evacuated tube solar water heater is studied experimentally in the radiation condition described in GB／T 18708. Results showed that the daily heat gain linearly increases with the increase of daily colllectible radiation, but Q17 and system's efficiency coefficient almost kept constant. It was also found that when the testing condition with the daily coUectible radiations being not less than 17 MJ／m2 changed into that of not less than 16 MJ/m2，change of Q17 and the system's energy efficiency coefficient was not insignificant, implying that the testing conditions about daily collectible radiation specified in the revised version of GB／T19141 was reasonable.","PeriodicalId":17502,"journal":{"name":"Journal of Yunnan Normal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79047908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7699/J.YNNU.NS-2014-051
Guangli Wang, W. Gao, Tao Liu, Wenxian Lin
As a new product on market, it's really necessary to develop testing equipments to test its thermal performance for all glass heat pipe evacuated solar collector tube. According to the national standard of all glass heat pipe evacuated solar collector tube latest issued by state, an automatic testing system for thermal performance of all-glass heat pipe evacuated solar collector tube is proposed. The system collects testing data by hardware like test platform or sensors, then automatically processes data and calculates the result of testing by software of upper computer. The testing system realizes automatic testing and improves testing efficiency and accuracy. It also has some practical application value.
{"title":"Development of automatic test system for thermal performance of all-glass heat pipe evacuated solar collector tube","authors":"Guangli Wang, W. Gao, Tao Liu, Wenxian Lin","doi":"10.7699/J.YNNU.NS-2014-051","DOIUrl":"https://doi.org/10.7699/J.YNNU.NS-2014-051","url":null,"abstract":"As a new product on market, it's really necessary to develop testing equipments to test its thermal performance for all glass heat pipe evacuated solar collector tube. According to the national standard of all glass heat pipe evacuated solar collector tube latest issued by state, an automatic testing system for thermal performance of all-glass heat pipe evacuated solar collector tube is proposed. The system collects testing data by hardware like test platform or sensors, then automatically processes data and calculates the result of testing by software of upper computer. The testing system realizes automatic testing and improves testing efficiency and accuracy. It also has some practical application value.","PeriodicalId":17502,"journal":{"name":"Journal of Yunnan Normal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78046281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2014-01-01DOI: 10.7699/J.YNNU.NS-2014-050
Hai Zhu, W. Gao, Wenxian Lin, Tao Liu, Ze-dong Li
In this paper, the domestic solar water heater with a vertical storage tank and a flat-plate collector, which is commercially available and popular in the market, was experimentally investigated. Firstly, natural circulation experiment platform of flat plate domestic solar water heater was set up. The effect of two different positions of upper connecting pipe on temperature variation in the water tank during the heating stage in the daytime and thermal performances was measured. Through the analysis of test data, the difference of temperature stratification in the water tank with upper connecting pipe at high position and at low position were studied respectively. Also the instantaneous efficiency in 10 minutes was defined and compared. The results showed that there was better temperature stratification in the water tank when it's upper connecting pipe at high position during heating stage. In addition, the instantaneous efficiency of solar water heater, which water tank with upper connecting pipe at high location under the natural circulation condition was superior to the water tank with upper circulation pipe at low position.
{"title":"Effect of Position of Upper Connecting Pipe on the Tank on Thermal Performance of Domestic Solar Water Heaters with a Vertical Storage Tank and Flat-plate Collectors","authors":"Hai Zhu, W. Gao, Wenxian Lin, Tao Liu, Ze-dong Li","doi":"10.7699/J.YNNU.NS-2014-050","DOIUrl":"https://doi.org/10.7699/J.YNNU.NS-2014-050","url":null,"abstract":"In this paper, the domestic solar water heater with a vertical storage tank and a flat-plate collector, which is commercially available and popular in the market, was experimentally investigated. Firstly, natural circulation experiment platform of flat plate domestic solar water heater was set up. The effect of two different positions of upper connecting pipe on temperature variation in the water tank during the heating stage in the daytime and thermal performances was measured. Through the analysis of test data, the difference of temperature stratification in the water tank with upper connecting pipe at high position and at low position were studied respectively. Also the instantaneous efficiency in 10 minutes was defined and compared. The results showed that there was better temperature stratification in the water tank when it's upper connecting pipe at high position during heating stage. In addition, the instantaneous efficiency of solar water heater, which water tank with upper connecting pipe at high location under the natural circulation condition was superior to the water tank with upper circulation pipe at low position.","PeriodicalId":17502,"journal":{"name":"Journal of Yunnan Normal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81135234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.4135/9781452229669.n1444
Chang Zhi
Green Marketing is a new field in the development of modern marketing, which will become the major form of marketing in the 21st century. This article mainly illustrates the connotations of green marketing and the status of its development in China. Besides,it also discusses how to implement green marketing.
{"title":"On green marketing","authors":"Chang Zhi","doi":"10.4135/9781452229669.n1444","DOIUrl":"https://doi.org/10.4135/9781452229669.n1444","url":null,"abstract":"Green Marketing is a new field in the development of modern marketing, which will become the major form of marketing in the 21st century. This article mainly illustrates the connotations of green marketing and the status of its development in China. Besides,it also discusses how to implement green marketing.","PeriodicalId":17502,"journal":{"name":"Journal of Yunnan Normal University","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85478468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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