Selection of pumps for beginners

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Implementation Plan 1: Necessity of the project: To increase the flow rate and pressure in the water pipelines and improve heat exchange efficiency, an additional pipeline pump will be installed in the existing pipelines. 2. Pump selection: 1. Selection criteria: 1.1 Physical and chemical properties of the fluid being transported: Fluid name, relative density, supply pressure, supply temperature, return pressure, corrosion rate, fouling, thermal resistance, pH value. For circulating water: 1.0 g/cm3, 0.24 MPa, 28°C, 0.2 MPa, 0.125 mm/year, 0.00035 m2·K/W, 7.0–8.5. 1.2 Process parameters: 1) Flow rate Q: The range of flow rates is 15–35 m3/h; the maximum flow rate of 35 m3/h will be used as the rated flow rate. 2) Head H: Under the actual process conditions of the pipeline network, as shown approximately in Figures 19-22, the calculation shows that Re=duρ/µ=1.24×105＞4000, indicating that the flow in the pipe is turbulent. ε=0.85 mm, ε/d=0.0085; from the chart, λ=0.034. Use the following formula to calculate the head. H = D + S + Σh1 + Σh2 (1-1) Given: D = 2.3 m, S = 1.4 m; ① Head loss in the inlet pipe: Σh1 = hf1 + Σhζ1 = λl1u1²/2d1g + Σζu1²/2g = *4 + (0.9*4 + 0.04 + 0.1)]*(1.24)²/2*9.81 = 0.4 m ② Head loss in the outlet pipe: Σh2 = hf2 + Σhζ2 = λl2u2²/2d2g + Σζu2²/2g = *(1.24)²/2*9.81 = 1.3 m Therefore, H = 5.4 m 3) Inlet pressure (Ps): Ps = 0.24 Mpa; Outlet pressure Pd = 0.5 Mpa 4) Temperature (T): T = 28°C 5) Net Positive Suction Head Available (NPSHa): NPSHa = PA/γ – PV/γ – Hg – ΔHA – S = (100 – 4.247)*10³/1000*9.81 – 0.4 – 3 = 6.36 m The actual installation height is 2.3 m, which is less than 6.36 m; hence it is suitable. 6) Operating status: Continuous. 1.3 Site conditions: The pipeline pump is installed within the instrument and drying station building; design temperature: 28°C, relative humidity: 80%, atmospheric pressure: 99.45 kPa. 2. Selection of pump type: 2.1 Schemes for selecting pipeline pumps: 2.1.1 Determination of the pump model: l Selection of pump type: Considering the limitations imposed by the available space on site, and taking into account advantages such as the simple structure of centrifugal pumps, steady flow rate, and ease of flow regulation, it is decided to use pipeline centrifugal pumps. l Selection of pump series and material: Based on the calculated flow rate Q and head H, the pump Wilo-IL80/160-1.5/4 can be selected from the table above. III. Implementation plan: 1. Plan description: Depending on the conditions at the site, a pipeline pump will be installed at the U-shaped section of the pump inlet pipe. To facilitate maintenance of the pump, a bypass circuit for the pump will also be added to ensure its continuous operation.