Rahul Kharat, Nitin Bhardwaj*, R.S. Jha have developed a correlation of heat transfer coefficient for helical coil heat exchanger to take into account of experimental and CFD results of different functional dependent variables such as gap between the concentric coil, tube diameter and coil diameter which strongly effects the heat treansfer within error band of 3-4%. The heat transfer coefficient is validated for a wide range of Reynolds number from 20,000 and 1,50,000 and specific ratio is from 0.55 to 2.25 that covers the most engineering helical coil heat exchanger
Q_conv=hA*(T_wire-T_∞ ) Where Qconv is the rate of heat transfer, Twire -T∞ denote the temperature difference between the wire and its surroundings, A, is surface area of the wire, and h is the coefficient of heat transfer (Armstrong p.5). The latter varies depending on the interaction between the surrounding air and the heated surface, and varies from 0.5 – 1000 W/m2K in air (forced and free). Radiative Heat Transfer The energy emitted, Eb, varies proportionately with the fourth power of temperature, T, of the radiator’s surface, as follows: E_b = ∂T^4 Where: Ԑ is the emissivity of the material, which indicates how a material compares to a “blackbody”; ∂ = 5.67e-8W/m2K4= Stefan-Boltzmann constant. Thus, equation  can be rewritten as: E_b = ԐT^4 The rate of radiative heat loss also varies proportionately with the surface area, A, of the radiating surface, and is expressed as follows: Q_rad = Ԑ*Ϭ*A(T_wire-T_∞^4 ) Equation  below illustrates the final energy balance equation that describes the temperature of the wire a function of varied parameters. mc dT/dt=i^2 R- ∂ԐA_s (T_wire^4-T_∞^4 )-hA_s
When Te = 15 °C, the cooling capacity decreased first and then increased with the generating temperatures ranging from 40 °C to 70 °C. This variation tendency is similar to that when Te = 10 °C. The worst performance occurred when the generating temperature was 65 °C, which was 720.3 W. In Fig. 5, it also can be seen that the critical condensing temperature when Te = 15 °C is a little higher than that when Te = 10 °C in most cases. The maximum difference between the two conditions is 3.7 °C when Tg = 55
I. Introduction This experiment uses calorimetry to measure the specific heat of a metal. Calorimetry is used to observe and measure heat flow between two substances. The heat flow is measured as it travels from a higher temperature to a lower one. Specific heat is an amount of heat required to raise the temperature of one gram of anything one degree Celsius.
3. Plot your data to create two lines with an intersection on a graph. Repeat any measurements that do not fall near the best-fit line. From the intersection, calculate the mole ratio of the reactants. Data Table: Experiment ml NaClO ml Solution B Temperature of Precipitate (degrees) 1 5 45 27.0 2 15 35 35.0 3 25 25 44.0 4 30 20 49.0 5 35 15 52.0 6 40 10 46.5 7 50 0 24.0 8 45 5 22.0 9 43 7 21.0 Graph: I eliminated the last two data points because it was making my graph weird.
iii. The readings of the two thermometers should, as far as possible, be taken simultaneously, and it should be ascertained that the wet bulb is receiving a sufficient water supply (WMO, 2008). The relative humidity was calculated using the following formulae by de Laaat and Savenije (2015); es = 0.6108e(17.27Ta)/(237.3+Ta) ed = es – γ(Tdry-Twet) Where es Saturation vapour pressure for air temperature at 2m height in kPa Ta 24 hour mean temperature in 0C γ is the psychometric constant = 0.067kPa.0C-1 at sea level The sling or whirl psychrometer A small portable type of whirling or sling psychrometer consists of two mercury-in-glass thermometers mounted on a sturdy frame, which is provided with a handle and spindle,
41.7 °C and 40.2 ° C 40-50 °C 4. 50 °C and 48 ° C 50-60 °C Average temperatures: (37.8+36.3)/2=37.05 °C (41.7+40.2)/2=40.95 °C (50+48)/2=49 °C Table 1 -The values of experiment Temperature (°C) Density (kg/m3) 26.5 995 37.05 992.5 40.95 991 49 990 70 984.856 80 982.524 90 980.272 100 977.93 Table 2. The values in steam table Temperature (°C) Density (kg/m3) 26.5 997 37.05 993 40.95
2.5.2 Apparent properties of FP emulsion The apparent properties of the FP emulsion were determined via simple observations and tests. 2.5.3 Zeta potential and particle size Zetasizer Nano ZS particle size analyzer (Malvern, UK) was used to measure the zeta potential, particle size, and the distribution of the FP emulsion. The particle size range of the microsphere was 5– 10 µm, and the microspheres should have good stability in the emulsion without coagulation. 2.5.4 Thermal property analysis 5 mg FP emulsion film sample was weighted, and the thermal property was analyzed using a Q500 thermogravimetric analyzer (TGA) (TA Co., USA), in the temperature range 30–80 °C at a heating rate of 10 °C/min in nitrogen atmosphere. 2.5.5 Atomic force probe scanning microscope (AFM) observation Small amount of FP
We then take the sample out of the water and immediately wipe it thoroughly, after which it is placed in the calorimeter with tap water. We then stir the water around the sample in order to quickly attain thermal equilibrium. We record the final temperature once thermal equilibrium of water and the sample together is attained. We then repeat the said steps but then with the other