化工学报
化工學報
화공학보
JOURNAL OF CHEMICAL INDUSY AND ENGINEERING (CHINA)
2014年
11期
4309-4314
,共6页
冷学礼%邱燕%田茂诚%李蔚
冷學禮%邱燕%田茂誠%李蔚
랭학례%구연%전무성%리위
传热%准则式回归%总传热系数
傳熱%準則式迴歸%總傳熱繫數
전열%준칙식회귀%총전열계수
heat transfer%correlation regression%overall heat transfer coefficient
目前换热器测试中的回归方法对测量过程和测试对象的要求仍有很多限制条件,对于换热管形状复杂的新型换热设备进行回归时,这些限制使获得准则方程式更加困难,测量周期增加。通过提出一种新的回归算法,以最小方差作为回归条件直接得到固定侧表面传热系数以及改变侧准则方程式,避免了Wilson法及等流速法等需要的限制条件。该方法仅依赖于对流换热两侧的热阻串联关系,得到的准则式与两侧流体工质、通道形态及流动状态是否相同均没有关系,降低了得到准则方程式的条件并简化测量过程,且与国家标准要求的测试条件对应。发展了使用二分法进行非线性回归得到准则方程式的算法,通过生成并使用模拟数据检验表明算法是准确可行的,使用实验数据求解得到的固定侧表面传热系数和流动侧准则方程指数也在合理的范围内。
目前換熱器測試中的迴歸方法對測量過程和測試對象的要求仍有很多限製條件,對于換熱管形狀複雜的新型換熱設備進行迴歸時,這些限製使穫得準則方程式更加睏難,測量週期增加。通過提齣一種新的迴歸算法,以最小方差作為迴歸條件直接得到固定側錶麵傳熱繫數以及改變側準則方程式,避免瞭Wilson法及等流速法等需要的限製條件。該方法僅依賴于對流換熱兩側的熱阻串聯關繫,得到的準則式與兩側流體工質、通道形態及流動狀態是否相同均沒有關繫,降低瞭得到準則方程式的條件併簡化測量過程,且與國傢標準要求的測試條件對應。髮展瞭使用二分法進行非線性迴歸得到準則方程式的算法,通過生成併使用模擬數據檢驗錶明算法是準確可行的,使用實驗數據求解得到的固定側錶麵傳熱繫數和流動側準則方程指數也在閤理的範圍內。
목전환열기측시중적회귀방법대측량과정화측시대상적요구잉유흔다한제조건,대우환열관형상복잡적신형환열설비진행회귀시,저사한제사획득준칙방정식경가곤난,측량주기증가。통과제출일충신적회귀산법,이최소방차작위회귀조건직접득도고정측표면전열계수이급개변측준칙방정식,피면료Wilson법급등류속법등수요적한제조건。해방법부의뢰우대류환열량측적열조천련관계,득도적준칙식여량측류체공질、통도형태급류동상태시부상동균몰유관계,강저료득도준칙방정식적조건병간화측량과정,차여국가표준요구적측시조건대응。발전료사용이분법진행비선성회귀득도준칙방정식적산법,통과생성병사용모의수거검험표명산법시준학가행적,사용실험수거구해득도적고정측표면전열계수화류동측준칙방정지수야재합리적범위내。
Correlation regression methods for heat exchanger have been developed in last several years, such as the method based on equal flow Reynolds number, the method based on equal flow velocity, and the Wilson plot technique, improvements of which contribute outstandingly in measuring heat transfer equipment. The defect in those methods is as follows. The methods based on equal flow Reynolds number and flow velocity restrict the flow conditions, duct structure and flow media in two ducts. The Wilson plot technique demands the exponent of Reynolds number. A new method is presented in this paper, which is similar to the Wilson plot technique but avoid above restrictions through searching proper coefficient and exponent in the correlation by examining the minimum variance in different fitting consequence, giving accurate heat transfer coefficients on the fixed side. The relation between two ducts is the thermal resistances in series. The method resolves the correlation fitting technique with a dichotomy, which is more accurate than linear regression analysis commonly used. The method is validated by simulated data first and then by experimental data. The result shows that the method is reasonable.