Transferencia De Calor Barras Infinitas

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INFORME DE LABORATORIO DE TRANSFERENCIA DE CALOR


1. TEMA
Perfiles de temperatura en barras de longitud infinita

2. OJETIVOS
* Determinar el perfil de temperaturas tanto en el acero como en el aluminio
* Determinar el coeficiente de trasferencia de calor por convección
* Determinar el calos disipado por cada barra en estado estable

3.TABLA DE DATOS

| BARRA DE ACERO 1" |
| 90 | 80 | 70 | 60 | 50 | 40 | 30 | 20 | 10 | 0 |
135 | 78.6 | 61.4 | 41.4 | 31.1 | 26.6 | 24.8 | 24.2 | 23.8 | 23.6 | 23.5 |
145 | 77.8 | 61.7 | 41.9 | 31.5 | 26.2 | 24.3 | 23.2 | 23.1 | 23 | 23 |
155 | 77.5 | 70.1 | 42.3 | 32 | 26.8 | 24.8 | 23.7 | 23.5 | 23.5 | 23.6 |
165 | 77.8 | 62 | 42.5 | 32.2 | 27 | 25 | 24 | 23.8 | 23.7 | 23.9 |175 | 78.1 | 61.2 | 42.2 | 32.2 | 27 | 25 | 23.9 | 23.7 | 23.6 | 23.6 |
185 | 78.1 | 60.4 | 42.6 | 32.7 | 27.6 | 25.5 | 24.2 | 24 | 23.8 | 24 |
195 | 79.1 | 62.3 | 43.2 | 33 | 27.9 | 26.5 | 24.8 | 24.6 | 24.5 | 24.6 |
205 | 79.2 | 62.5 | 43.3 | 33.3 | 28.1 | 26.2 | 25.1 | 25 | 24.8 | 24.9 |
215 | 78.7 | 62.5 | 43.7 | 33.6 | 28.6 | 26.6 | 25.4 | 25.3 | 25.1 | 25.2 |
225 | 80 | 63 |43.7 | 33.8 | 28.7 | 26.7 | 25.6 | 35.5 | 25.4 | 25.4 |
235 | 77.7 | 62.6 | 42.6 | 32.7 | 27.8 | 26 | 25.7 | 25.1 | 24.8 | 24.7 |


| BARRA DE ALUMINIO 1/2" |
135 | 84.1 | 72.8 | 62 | 51.9 | 36.9 | 30.5 | 27 | 25.3 | 25.1 | 24.8 |
145 | 83.5 | 71.6 | 62.1 | 52.2 | 37.6 | 31.2 | 27.6 | 26.5 | 24.8 | 24.7 |
155 | 85.2 | 73.1 | 64 | 53.8 | 39 | 32.5 | 28.9 | 26.9 | 26.6 | 25.8 |165 | 85 | 73.1 | 62.3 | 52.2 | 37.6 | 31.3 | 28.1 | 26.3 | 26.1 | 25.6 |
175 | 84.6 | 72.4 | 62.3 | 52 | 37.3 | 31 | 27.6 | 26 | 25.6 | 25.2 |
185 | 84.7 | 72.1 | 63.9 | 53.9 | 39.3 | 32.8 | 29.1 | 27.2 | 26.7 | 26.1 |
195 | 85 | 72.5 | 64.3 | 54.6 | 40.1 | 33.5 | 29.6 | 27.7 | 27.3 | 26.8 |
205 | 85.1 | 72.7 | 64.6 | 54.7 | 40.1 | 43.6 | 29.8 | 28.5 | 27.1 | 26.9 |
215 | 84.7 | 72 |64.5 | 55 | 40.7 | 34.2 | 30.6 | 28.6 | 27.5 | 27.3 |
225 | 85.3 | 73.3 | 65 | 55.2 | 40.7 | 34.1 | 30.3 | 28.5 | 28.2 | 27.8 |
235 | 83.2 | 71.6 | 60.6 | 50.6 | 36.5 | 30.6 | 27.2 | 25.7 | 25.3 | 25.2 |


| BARRA DE ALUMINIO 1" |
135 | 93.9 | 88.5 | 78.6 | 67 | 56 | 47.9 | 37.3 | 31.6 | 39.1 | 28 |
145 | 93.4 | 87.6 | 68.4 | 67 | 56.2 | 48.1 | 37.6 | 32.2 | 29.2 | 28 |
155| 95.3 | 89.5 | 80.2 | 68.7 | 57.8 | 49.7 | 39 | 33.4 | 30.3 | 29 |
165 | 94.5 | 88.5 | 78.7 | 67 | 56.2 | 48.1 | 37.9 | 32.8 | 30.1 | 28.8 |
175 | 94.3 | 88.7 | 79.3 | 67.8 | 56.8 | 48.6 | 38 | 32.7 | 30 | 28.7 |
185 | 93.3 | 88.5 | 80.5 | 69.3 | 58.8 | 50.7 | 39.7 | 33.8 | 30.7 | 29.4 |
195 | 94 | 88.8 | 80.9 | 70.1 | 59.7 | 51.6 | 40.6 | 34.7 | 31.6 | 30.1 |
205 | 94.1 | 88.9 |80.9 | 70.1 | 59.7 | 51.8 | 41 | 35.1 | 32.1 | 30.7 |
215 | 94.3 | 89.3 | 81.5 | 70.8 | 60.6 | 52.8 | 41.8 | 36 | 32.7 | 31.2 |
225 | 94.1 | 89.2 | 82 | 71.3 | 61 | 53.1 | 42.1 | 36 | 32.8 | 31.3 |
235 | 95.3 | 88.5 | 78.3 | 66.9 | 56.3 | 48.6 | 38.8 | 33.7 | 31 | 29.7 |




4. EJEMPLO DE CALCULOS

PARA LA BARRA DE ACERO DE 1”

* Diámetro: 1”
* K:15.1 (W/m K)
* a: 3.91x10-6 (m2/s)
* Área: 5.066x10-4 (m2)
* Perímetro 0.0798 (m)
* Ts: 180 ºC
* Ta: 21ºC
* Tiempo: 120 min
* Longitud: 90 cm

Cálculo de Coeficiente de conveccion

h=k*A*lnTx-TaTb-Ta2P*x2
Donde:
K= Conductividad térmica del material
A=Área de la barra
Ts= Temperatura de la fuente de calor
Ta=Temperatura ambiente
P=Perímetro de la barra
X=Longitud de la barra
T=Temperatura en el punto de análisis

h=15.1*5.06x10-4*ln24.7-2177.7-2120.0798*0.092

h=89.06 Wm2K

Calculo de q
qf=M
M=h*P*k*Acθb
qf=89.06*0.0798*15.1*5.06x10-4(77.7-21)

qf=13.21 W
5. GRÁFICOS

* Acero 1’’




* Aluminio 1/2’’...