Executive Summary(1/2) Definition The experiment is aimed to compare the performance of different kinds of heat insulation materials under normal conditions. The results of the experiment would be quantified into the details including the texture, thickness, exterior color and ventilation. 4
Literature Review(1/2) Define how various factors would accelerate or decelerate the cooling rate. 《 Fabric Selection for a Liquid Cooling Garment 》 《水压机泵站工作液体降温问题分析》 8
Literature Review(2/2) △ T=f(LP, S, M, C, T, HC, CA) 9 properties of the liquid size of the container Heat conduction property of container physical properties of insulation material contact of the air color of the material thickness of the material
Preparation & Location Preparation Material Container: Beaker Kerosene thermometer Experiment Location C Builiding, Room 306. The room temperature is 26 centigrade. 11 Flax, Black Flax, White Cotton, Black Cotton, White Beaker,1 50ml
Variables & Blocking 12 Variable Selection Material, Color, Layer, and Ventilation Setting Variables Blocking Two thermometers which have different calibration FactorMaterialColorLayerVentilation +HeavyBlackMultipleYes -LightWhiteSingularNo 4 variables, 2 levels per variable, 2 replications per treatment, 2 blocks, Full factorial
14 We boil tap water to approximately 100 degrees Celsius, and then quickly pour 200 ml boiling water into the two beakers and read the temperature. We begin reading when we first see the temperature is steady and begins to drop. We count 3 minutes before a second reading. Using the two readings with 3-minute interval, the drop of temperature within the 3 minutes could be calculated.
Warm up of the beakers and the thermometers To ensure that the heat won’t lose through other channels. Wrap the cloth tightly to the beaker Use slim clip to ensure that the least width is overlapped. Pad the cup with a paper dish underneath To minimize the heat conducted through the bottom. 16
Initial Model (1/2) 18 No.FactorsNo.Factors 1Material9Color* ventilation 2Color10Layer*Ventilation 3Layer11Material*Color*Layer 4Ventilation12Material*Color*Ventila tion 5Material*Color13Material*Layer*Ventil ation 6Material*Layer14Color*Layer*Ventilati on, 7Material*Ventil ation 15Material*Color*Layer* Ventilation 8Color*Layer Use these 15 factors in a GLM and calculate coefficients in Minitab.
Modified Model (1/3) Then we delete the following factors and recalculate one by one. Material*Color*Layer*Ventilation Material*Color*Layer Material* Layer*Ventilation Color*Layer*Ventilation Material*Color*Layer Color*Layer Material*Layer 20
Modified Model (2/3) Also we get S = 0.505930 R-Sq = 96.32% R-Sq （调整） = 95.04% 项 系数 系数标准误 T P 常量 6.65313 0.08944 74.39 0.000 Material Light -0.45313 0.08944 -5.07 0.000 Color White 0.32813 0.08944 3.67 0.001 Layer Singular -0.29688 0.08944 -3.32 0.003 Ventilation No -1.95938 0.08944 -21.91 0.000 Material*Color Light White -0.40312 0.08944 -4.51 0.000 Material*Ventilation Light No 0.30938 0.08944 3.46 0.002 Color*Ventilation White No -0.39687 0.08944 -4.44 0.000 Layer*Ventilation Singular No 0.40313 0.08944 4.51 0.000 21
Regression Model (4/4) We transform TempDiff into Exponential form, and get the residual plot as below: We see some obvious patterns, we don’t recommend to transform the data in this way. 35
Results explanations No ventilation can remarkably maintain the high level of heat preservation. Materials have main effect of heat preservation as well. Colors of material have main effect of heat preservation as well. Thickness of material has less but also main effect of heat preservation as well. Interaction explanation. 36
Possible causes Ventilation-absence condition has the best ability of maintaining heat may result in that heat is lost mostly from the top of the cup, more than from the wall of cup. White color surprisingly has better ability of maintaining heat. Heavy cloth has better heat maintaining ability, which corresponds to our intuition. However, layers have less effect. 37
Error sources Inequity of preliminary heating results the different original conditions of materials such as cloth and the cups. Two thermometers have different abilities of measuring such as sensitivity to temperature changes and measurement resolution. System errors from two experimenters reading the thermometers such as view angular. Water incrustation or impurities in later treatments because of repetitive uses. Impurities in water may affect the temperature decrease rates. Room temperature may change during the relatively long period time during the experiment process. 38