Rational selection of pumps requires comprehensive consideration of the comprehensive technical and economic indicators such as the investment and operation cost of pumping units and pumping stations, so as to make them conform to the principles of economy, safety and applicability. It includes the following aspects:
1) High efficiency, low noise and energy-saving water pumps should be selected, and elimination products should be strictly prohibited.
2) Pumps should be selected according to the designed flow rate and required lift, and considering the decrease of pump output caused by wear and tear, pumps can be selected by multiplying the calculated head H by 1.05-1.10 coefficients; pumps whose head decreases gradually with the increase of flow rate should be selected as characteristic curves, so that the pumps work steadily and work reliably in parallel; and the operating points of pumps should be maintained in high-efficiency intervals. OK. It saves energy and is not easy to damage the parts.
3) When there is no regulating facilities in water supply network, it is advisable to use speed regulating pump group or rated speed pump group to run water supply in groups. The maximum water output of the pump group should not be less than the designed water flow rate of the district, and should be checked under the condition of fire protection.
4) Choosing the lifting pumps of water tanks and towers should minimize the number of pumps and be equipped with one pump; when a single pump can meet the requirements, it is not appropriate to use multiple parallel pumps; if multiple parallel pumps or large and small pumps must be used, the type and number of pumps should not be too many, the type should not exceed two, and the lift range of pumps should be similar; when running in parallel, each pump should still be used. It runs in the high efficiency area.
5) The designed water supply flow of the variable frequency speed regulating pump (group) should satisfy the requirement of the maximum designed second flow in the domestic water supply system. The power supply must be reliable (double power supply or double circuit power supply); the working point of the pump should be selected in the high-efficiency working area of the pump characteristic curve (Q-H curve), and not in the extension line of the Q-H curve. The most disadvantageous working point of the design should be at the right end of the high-efficiency section of the pump characteristic curve, that is, the point where the pump has the largest water output and the lower head but can meet the requirements, that is, the pump characteristic. The intersection point between the low point of the high efficiency zone of the performance curve and the characteristic curve of the pipeline. The working range of pump speed regulation can be within the high efficiency section of the pump as far as possible; the speed regulation range should be between 25% and 100% of the water supply of the pump; the equipment should have the function of automatic water level control.
6) Pump units of domestic pressurized water supply system should be equipped with standby pumps. The water supply capacity of standby pumps should be greater than that of the largest running pump. Pumps should be switched automatically and run alternately.
7) The voltage of the distribution motor of the pump shall be the same, and the power supply mode shall be the same as that of the State Grid.
Learn More:
1) High efficiency, low noise and energy-saving water pumps should be selected, and elimination products should be strictly prohibited.
2) Pumps should be selected according to the designed flow rate and required lift, and considering the decrease of pump output caused by wear and tear, pumps can be selected by multiplying the calculated head H by 1.05-1.10 coefficients; pumps whose head decreases gradually with the increase of flow rate should be selected as characteristic curves, so that the pumps work steadily and work reliably in parallel; and the operating points of pumps should be maintained in high-efficiency intervals. OK. It saves energy and is not easy to damage the parts.
3) When there is no regulating facilities in water supply network, it is advisable to use speed regulating pump group or rated speed pump group to run water supply in groups. The maximum water output of the pump group should not be less than the designed water flow rate of the district, and should be checked under the condition of fire protection.
4) Choosing the lifting pumps of water tanks and towers should minimize the number of pumps and be equipped with one pump; when a single pump can meet the requirements, it is not appropriate to use multiple parallel pumps; if multiple parallel pumps or large and small pumps must be used, the type and number of pumps should not be too many, the type should not exceed two, and the lift range of pumps should be similar; when running in parallel, each pump should still be used. It runs in the high efficiency area.
5) The designed water supply flow of the variable frequency speed regulating pump (group) should satisfy the requirement of the maximum designed second flow in the domestic water supply system. The power supply must be reliable (double power supply or double circuit power supply); the working point of the pump should be selected in the high-efficiency working area of the pump characteristic curve (Q-H curve), and not in the extension line of the Q-H curve. The most disadvantageous working point of the design should be at the right end of the high-efficiency section of the pump characteristic curve, that is, the point where the pump has the largest water output and the lower head but can meet the requirements, that is, the pump characteristic. The intersection point between the low point of the high efficiency zone of the performance curve and the characteristic curve of the pipeline. The working range of pump speed regulation can be within the high efficiency section of the pump as far as possible; the speed regulation range should be between 25% and 100% of the water supply of the pump; the equipment should have the function of automatic water level control.
6) Pump units of domestic pressurized water supply system should be equipped with standby pumps. The water supply capacity of standby pumps should be greater than that of the largest running pump. Pumps should be switched automatically and run alternately.
7) The voltage of the distribution motor of the pump shall be the same, and the power supply mode shall be the same as that of the State Grid.
Learn More:
评论
发表评论