Modern society is concerned about low-carbon environmental protection, energy saving and emission reduction concept, Shanghai Shangcheng pump valve has also been advocating this new type of values, and this concept is actually used in our products. Today we will introduce the chemical pump how to save energy.

1 improve the feed pump overhaul process to reduce hydraulic losses

1.1 Improve the smoothness of the flow path

In the overhaul of the impeller and impeller flow part of the rust, scale, burr, fly edge grinding and polishing, so that the smoothness of the flow channel to △ 4 or more, to reduce the friction between the water and the flow channel wall impact vortex loss. However, by the site conditions, to the entire part of the through-flow grinding is not easy, should focus on the influence of the efficiency of the key parts of the polishing and grinding, such as: the guide vane parts, impeller inlet parts, impeller outlet parts and so on. Grinding to see the metal luster can be, do not destroy the original shape of the runner line.

1.2 Improve the impeller outer wall and the pump casing inner wall of the smoothness of the maintenance of the impeller outer wall and the pump casing inner wall of the embroidery scale, burr grinding smooth, while maintaining the impeller scoop deviation does not exceed the prescribed value, reduce disc friction loss.

1.3 Reduce the impact loss of impeller outlet

The impeller and guide vane flow centre should be in the middle, the impeller channel should not exceed the guide vane channel, and the impeller outlet should not have burrs and flying edges. Installation, rotor and pump casing axial dimensions should be controlled within the permissible range, the pump's axial displacement changes in response to the impeller and guide vane at all levels of the differences in the alignment, normal operation should control the pump's axial displacement in order to reduce the impeller outlet fluid impingement loss.

2 Reduce volume loss to improve operating efficiency

(1) Reduce the leakage loss in the pump, improve the machining accuracy and assembly quality of the parts, reduce the radial clearance of the throttle sleeve in front of the balance disc and the radial clearance of the sealing ring before and after the impeller and the sealing ring of the guide vane, and reduce the pressure energy loss caused by the liquid in the pump leaking from the high-pressure side to the low-pressure side. Impeller sealing ring, guide vane sleeve, balance disc before the throttle and other parts should be selected with high hardness materials, and improve wear resistance of the heat treatment.

(2) cold start to the pump, according to the requirements of the regulations should be sufficient to warm up the pump, if the pump is not sufficient to warm up, the pump body is prone to produce a large thermal temperature difference between the top and bottom, so that the rotor produces a bow-shaped deformation, at this time to start the pump is easy to make the internal sealing gap grinding large, resulting in internal leakage and return flow volume loss increases.

(3) operation carefully monitor the pump's axial run and balance the changes in water pressure after the disc, normal operation, the balance of the disc after the water pressure than the pump's inlet pressure of a wide range of large changes should be timely maintenance, reduce leakage losses, improve the pump's volumetric efficiency.

(4) adjust the load should be smooth, to avoid large fluctuations in water pressure, to maintain the continuous and stable operation of the feed pump to reduce the pump's axial fluctuation, so as not to cause seal gap wear.

3 Reduce the leakage loss of water supply system

(1) normal operation of the water supply system of the discharge door, the water door and the pump body discharge door, the boiler's regular sewage door, the accident discharge door should be closed tightly, hand check the door should be cool. The valve is not tight should be carried out in a timely manner.

(2) Reduce the leakage loss of feed pump recirculation door. Feed pump recirculation device is used to keep the feed pump start, just put into operation, stop the boiler water supply to maintain a ZUI small flow, in order to prevent operation due to the flow of small heat, feed water vaporisation, resulting in accidents. The recirculation door should be closed tightly during normal operation. In the field, due to the structure and materials and other issues, the recirculation door in a very large pressure difference under the action of scouring, general leakage is serious, a large number of high-pressure feedwater back to the deaerator for useless, resulting in a waste of electricity, and even affect the boiler water supply. At this time should be timely withdrawn from the operation, repair the leakage of serious recirculation door, to maintain its good tightness. In addition, start the feed pump, when the pump is running normally, should be closed in time after the recirculation door, to reduce the loss of power at this time.

(3) standby pump outlet backstop should be strict, cast linkage standby pump outlet door is generally in the open state. Backstop door is not strict caused by high pressure feed water leakage through the pump body back to the deaerator, and even caused by the standby pump reversal, should be immediately withdrawn from the standby to deal with, not only to reduce high pressure feed water pressure energy loss, but also to ensure the safety of the equipment standby. In addition, in the case of meeting the needs of water supply, can only keep ‘ water pump outlet door in the fully open state standby, other standby pump outlet door can be closed to reduce leakage losses.

4 Application of frequency control

Water pump frequency conversion speed control operation refers to the water pump in the adjustable speed motor drive operation, by changing the speed to change the working condition of the pump device point. This greatly expands the effective working range of the pump, is a very important and applicable regulation in the project. At present, the motor consumption of electricity accounts for about 65% of industrial power consumption, the vast majority of equipment using the motor or general non-speed motor. If these non-speed-regulating motors are transformed into speed-regulating motors, so that their power consumption varies with the load, a large amount of power can be saved. By the centrifugal pump principle, in similar circumstances the flow rate, head and power of the pump are proportional to its rotational speed of the primary, secondary and tertiary, respectively. For frequent changes in water consumption occasions, the use of frequency conversion speed control pump water supply, can significantly reduce the throttling loss, with obvious energy-saving effect.

Water pump frequency conversion speed control technology compared with other speed control technology, has the following advantages: First, high speed control efficiency. Frequency control is in the frequency change, the motor is still in the frequency of the synchronous speed near the operation, basically maintain the rated speed difference, speed loss does not increase. Therefore, frequency conversion speed control pump is a kind of high-efficiency speed pump. Second, the speed range is large. Frequency converter speed range up to 1 per cent -100 per cent, and in the entire speed range has a high speed efficiency, when the speed range is less than 30 per cent, the frequency converter efficiency up to 90 per cent. So the frequency conversion speed control pump is especially suitable for speed range wide, often in the low load state of operation. Third, speed conversion is convenient. The original motor speed conversion, do not have to replace the motor. Fourth, continuous speed regulation, small starting current. Choose better running speed, can achieve low-speed start, smooth speed regulation, ZUI high-speed is not affected by the power supply, the motor can be high-speed, miniaturisation. Fifthly, the frequency conversion device can be used as starting equipment. The motor is started to a certain speed by the inverter power supply, and then disconnected from the inverter power supply, the motor is accelerated to full speed by the industrial frequency power supply. Sixth, the main circuit can maintain direct power supply. When the frequency conversion device fails, it can be withdrawn from operation and be directly powered by the main circuit, which does not affect the continued operation of the pump.