Concept explainers
In a supercomputer, signal propagation delays arereduced by resorting to high-density circuit arrangements which are cooled by immersing them in a specialdielectric liquid. The fluid is pumped in a closed loopthrough the computer and an adjoining shell-and-tubeheat exchanger having one shell and two tube passes.
During normal operation, heat generated within the computer is transferred to the dielectric fluid passing through the computer at a flow rate of
dielectric fluid may be assumed to have constant properties of
(a) If the heat exchanger consists of 72 thin-walled tubes, each of 10-mm diameter, and fully developed how is assumed to exist within the tubes, what is the convection coefficient associated withflow through the tubes?
(b) If the dielectric fluid enters the heat exchanger at
(c) For the exchanger with the tube length per passdetermined in part (b), plot the outlet temperature
of the dielectric fluid as a function of its flow ratefor
(d) The site specialist for the computer facilities isconcerned about changes in the performance of the water chiller supplying the cold water
(e) Repeat the performance analysis of part (d) todetermine the effect of
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Fundamentals of Heat and Mass Transfer
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- #2 Separate streams of steam and air flow through the turbine and heat exchanger arrangement shown in the figure below, where the air stream mass rate m'5 ranges from 1500 kg/min to 3500 kg/min in increments of 500 kg/min and Wt1= 10,000 kW,. Steady-state operating data are provided on the figure. Heat transfer with the surroundings can be neglected, as can all kinetic and potential energy effects. Steam in 1500 kg/min 2000 kg/min 2500 kg/min Mass Rate of Air M5 in kg/min 3000 kg/min 3500 kg/min Turbine T₁ = 600°C P₁ = 20 bar W₁ T3 T₂=400°C P2 10 bar Temperature T6 = 1200 K P6 = 1 bar tmt tm Heat exchanger TWO TURBINE PROBLEM Py = 10 bar T3 = ? Analyze the two-compressor system for different air mass flow rates into the heat exchanger. Provide clearly detailed professional written sample of the calculations needed to analyze each component of the system and the overall system. Complete the following table and plot the mass of air M5 against the Temperate T3, plot the mass rate M5…arrow_forwardConsider the two-tank liquid-level system shown below with cross-sectional areas, A₁ and A2, respectively. The liquid enters tank 1 through a pipe with a volumetric flow rate of q. The liquid can flow between the two tanks through a valve of linear resistance R₁. The liquid discharges to atmospheric pressure from tank 2 through a valve of resistance R₂. Assume both tanks are exposed to atmospheric pressure and the density p of the liquid is constant. Your tasks: 91 00 A₁ /hi R₁ A2 The R₂ C- A. Derive a differential equation model for the system behavior in terms of the liquid heights h₁ and h2. B. Determine the transfer function G(s) = H₂(s)/Q₁(s) for the system in terms of flow resistances R₁ and R₂, hydraulic capacitance values C₁ and C2, and gravity, g. (1arrow_forward6. In an heat exchanger of parallel flow type, water enters at 60°C and leaves at 80°C while oil of specific gravity 0.8 enters at 250°C and leaves at 100°C. The specific heat of oil is 2.5 kJ/kg K and surrounding temperature is 300 K. Determine the loss in availability on the basis of one kg of oil flow per second. [Ans. – 59.9 kJ]arrow_forward
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