The only real disadvantage of this system is that it can't be installed in existing buildings and is more suitable for new properties. Small pipe diameters and fewer fittings save on installation time and labour costs. Since there are also no other draw-off points on the same pipe, pressure and temperature variations are minimal when taps are turned on and off. With joints only at the manifold and the radiator/taps, the risk of leakage from joints is considerably reduced and there are no connections within the walls or floors. The system can be designed with one single pipe dimension from the manifold to the draw-off point, which simplifies design and installation work. doi: 10.1016/j.ijhydene.2012.04.034.The basic principle of the Uponor manifold system is to provide joint free pipe runs from a centrally positioned manifold to each radiator valve or tap or water outlet. International Journal of Hydrogen Energy. "Discrete approach for flow-field designs of parallel channel configurations in fuel cells". "Flow field designs of bipolar plates in PEM fuel cells: theory and applications, Fuel Cells". "Analytical solution of flow coefficients for a uniformly distributed porous channel". "Flow distribution and pressure drop in plate heat exchanges. "A model for flow distribution in manifolds". "Theory of flow distribution in manifolds". "Pressure drop and flow distribution in parallel-channel of configurations of fuel cell stacks: Z-type arrangement". "Pressure drop and flow distribution in parallel-channel of configurations of fuel cell stacks: U-type arrangement". "A generalized model of the flow distribution in channel networks of planar fuel cells". "Methodology for multi-scale design of isothermal laminar flow networks". "Uniform flows in rectangular lattice networks". Industrial & Engineering Chemistry Fundamentals. Transactions of the American Society of Civil Engineers. Wang also established a direct, quantitative and systematic relationship between flow distribution, pressure drop, configurations, structures and flow conditions and developed an effective design procedures, measurements, criteria with characteristic parameters and guidelines on how to ensure uniformity of flow distribution as a powerful design tool. The present models have been extended into more complex configurations, such as single serpentine, multiple serpentine and straight parallel layout configurations, as shown in Fig. Wang elaborated the most complete analytical solutions of Eq.2 - Eq.5. Their analytical solutions had been well-known challenges in this field for 50 years until 2008. The second term in the left hand represents a frictional contribution known as the frictional term, and the third term does the momentum contribution as the momentum term. Only under very slow laminar flow, Q 2 may be equal to Q 3.Įq.2 - Eq.5 are second order nonlinear ordinary differential equations for dividing, combining, U-type and Z-type manifolds, respectively. Our observations show that the greater the velocity (or momentum), the more fluid fraction through the straight direction. Obviously this disobeys our observations. Thus the velocities should be equal in two outlets or the flow rates should be equal according to the assumptions. 3, their resistances are same, R 2 = R 3. Since they have same diameter and length in Fig.
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