华南理工大学学报(自然科学版)
華南理工大學學報(自然科學版)
화남리공대학학보(자연과학판)
JOURNAL OF SOUTH CHINA UNIVERSITY OF TECHNOLOGY(NATURAL SCIENCE EDITION)
2013年
12期
125-128
,共4页
对流传热%能量公理%电场%电热效应
對流傳熱%能量公理%電場%電熱效應
대류전열%능량공리%전장%전열효응
convective heat transfer%energy postulate%electric field%electrothermal effect
外场作用能够有效地强化传递过程,电场强化传热便是其中的一个研究热点。为揭示电场强化对流传热过程的热力学机理,文中利用能量公理建立了电场作用下的基本热力学关系,定义了电场作用下的焓和吉布斯函数,导出了等温条件下焓随电场的变化以及绝热条件下温度随电场的变化关系。结果表明:对于常用的液体物质,在有效的工作温度范围内,焓在等温过程中随电场增加而减小,温度在绝热过程中随电场增加而上升;如果在系统放热过程中施加电场作用,焓减小意味着系统能够放出更多的热量,温度上升意味着更利于向低温热源放热,因此电场作用能够提高传热效率。文中还基于此热力学机理提出了一个电场强化对流传热过程的原理图。
外場作用能夠有效地彊化傳遞過程,電場彊化傳熱便是其中的一箇研究熱點。為揭示電場彊化對流傳熱過程的熱力學機理,文中利用能量公理建立瞭電場作用下的基本熱力學關繫,定義瞭電場作用下的焓和吉佈斯函數,導齣瞭等溫條件下焓隨電場的變化以及絕熱條件下溫度隨電場的變化關繫。結果錶明:對于常用的液體物質,在有效的工作溫度範圍內,焓在等溫過程中隨電場增加而減小,溫度在絕熱過程中隨電場增加而上升;如果在繫統放熱過程中施加電場作用,焓減小意味著繫統能夠放齣更多的熱量,溫度上升意味著更利于嚮低溫熱源放熱,因此電場作用能夠提高傳熱效率。文中還基于此熱力學機理提齣瞭一箇電場彊化對流傳熱過程的原理圖。
외장작용능구유효지강화전체과정,전장강화전열편시기중적일개연구열점。위게시전장강화대류전열과정적열역학궤리,문중이용능량공리건립료전장작용하적기본열역학관계,정의료전장작용하적함화길포사함수,도출료등온조건하함수전장적변화이급절열조건하온도수전장적변화관계。결과표명:대우상용적액체물질,재유효적공작온도범위내,함재등온과정중수전장증가이감소,온도재절열과정중수전장증가이상승;여과재계통방열과정중시가전장작용,함감소의미착계통능구방출경다적열량,온도상승의미착경리우향저온열원방열,인차전장작용능구제고전열효솔。문중환기우차열역학궤리제출료일개전장강화대류전열과정적원리도。
Transfer processes can be effectively enhanced by external fields,and the heat transfer process enhanced by electric field is a research hotspot in nowadays.In order to reveal the thermodynamic mechanism of convective heat transfer enhanced by electric field,fundamental thermodynamic equations including the influence of electric field are put forward based on the energy postulate,enthalpy and Gibbs function are redefined with the effect of electric field,and the expressions of the partial derivatives of enthalpy and temperature with respect to electric fields are derived.The results indicate that,for most liquids in a valid temperature range,the enthalpy decreases in isothermal process and the temperature increases in adiabatic process with the increase of external electric field. When an external electric field is applied on the heat release stage,the decreased enthalpy of the liquid medium means that more heat can be released,while the increased temperature of it means that the heat release to lower reservoir tends to be more effective.Thus,it is concluded that the electric field effectively enhances the convective heat transfer.Based on the proposed thermodynamic mechanism,a principle diagram is finally presented to de-scribe the convective heat transfer enhanced by electric field.