Principles and measures for energy-saving renovation of water pumps
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The principles and measures for energy-saving renovation of water pumps: When many people hear about energy-saving renovations for water pumps, they usually have two questions or doubts – first, how is it possible to achieve energy savings? What is the principle of energy saving? Second, are the energy-efficient impellers (pumps) you design more efficient than the branded products of well-known large companies? How is that possible? Next, I will start by addressing these two issues that are of concern to everyone, and discuss the principles and measures for energy-saving upgrades of pumps in our company. First, how can we achieve energy savings? What is the principle of energy saving? We can summarize the principle of energy savings in water pump systems in one sentence: \"Operate high-efficiency pumps at their optimal operating points to reduce pipeline losses, especially throttling losses.\" This sentence contains three key terms: high-efficiency water pump (pump efficiency), high-efficiency point, and pipeline losses, which are also the three key aspects for energy savings in water pump systems. (1) High-efficiency water pump (pump efficiency): To save energy, the pump efficiency must be high. The efficiency of a water pump depends first on its design quality, and secondly on the precision and quality of its manufacturing ； (2) Efficiency points: For the same water pump, its efficiency varies at different flow rates; it is generally highest near the rated operating conditions. If the operating conditions deviate significantly from the rated ones, even if the pump’s rated efficiency is high, its actual operating efficiency will be low. Going a step further, for high efficiency it is also necessary to consider the motor’s load rate and its efficient operating range; in other words, the overall efficiency of the entire water pump system should be at its optimal level. (3) Pipeline losses: Pipeline losses should be minimized, and throttling losses should be eliminated as much as possible. We achieve energy savings by focusing closely on three key aspects: pump efficiency, the operating point of maximum efficiency, and pipeline losses. We conduct scientific analysis and diagnosis of the actual operating conditions of the pumps, and by utilizing advanced theories and scientific methods, we identify the problems existing in the pump system. Targeted and effective measures are then taken to fully exploit all potential opportunities, thereby increasing the rated efficiency of the pumps, ensuring that their actual operating parameters are at the point of maximum efficiency, and minimizing pipeline losses. It is through the integrated approach of these three aspects that we achieve our energy-saving goals – this is our principle for energy conservation. Second, are the energy-efficient impellers (pumps) we design more efficient than the branded products of well-known large companies? How is that possible? The answer is very likely. The main reason is that we design and manufacture products specifically tailored for particular operating conditions, whereas the branded products of well-known manufacturers are not designed for a specific set of conditions but rather as generic series products suitable for multiple applications. This leads to the following differences: (1) The pumps produced by well-known manufacturers are part of standardized series; each model is intended to be applicable across a wide range of conditions. Therefore, it is required that they maintain high efficiency over a broad range of flow rates. To achieve this, the highest possible efficiency has to be sacrificed, meaning that during design, priority is given to ensuring an average efficiency over a wide range, with peak efficiency being considered secondarily. In our energy-saving upgrades, for specific operating conditions, we prioritize achieving the highest efficiency peaks in a limited range, which means the efficiency may be higher than that of products from larger manufacturers. (2) The requirements regarding certain parameters of the impeller for pump efficiency and cavitation resistance are contradictory to each other; in order to meet a wide variety of operating conditions, pumps manufactured by leading companies must have good cavitation resistance, which comes at the cost of efficiency. In the face of specific operating conditions, such as a backflow circulating water system, it is possible to design a larger required net positive suction head to prevent cavitation, which in turn helps to improve efficiency. (3) To reduce the shock loss of water pumps when operating at high flow rates, the impellers of conventional water pumps are designed with a larger impact angle to accommodate such high-flow conditions; this, in turn, increases the shock loss under other operating conditions. For a specific range of flow rates, we can choose an appropriate angle of attack that is neither too large nor too small, thereby reducing shock losses and improving efficiency. There are many others, but I won’t list them all here. Our specific energy-saving measures are as follows: 1. Conduct on-site investigations to accurately diagnose the problems existing in the system, and determine the design parameters in a targeted and precise manner. 2. Improve the rated efficiency at the design operating point through advanced design skills and energy-saving concepts. We make extensive use of advanced design theories such as three-dimensional flow theory, combine them with CFD flow field analysis and dynamic simulation, target specific operating ranges, draw on excellent hydraulic models, and employ advanced CAD design software. Most importantly, we have experienced senior designers who bring decades of design experience and insights to bear, enabling the pumps and impellers designed to achieve efficiencies close to the limits under specific operating conditions. Old pumps or impellers are replaced with high-efficiency pumps or impellers (three-dimensional flow impellers). 3. Eliminate inefficiencies caused by operating condition deviations. Ordinary water pumps are series-produced standardized products, with a limited set of specifications spaced at appropriate intervals to meet a wide variety of operating conditions; it is not possible to design and manufacture them based on the specific requirements of a particular factory. The limitations of the pump product range, coupled with the great diversity in actual production conditions, inevitably lead to a mismatch between the performance parameters of pumps and the requirements of actual manufacturing processes as well as the actual resistance in the pipelines. This results in pumps operating outside their efficient range ； Changes in the pump load due to various reasons can also cause the pump to deviate from its high-efficiency range ； All of this leads to inefficiency and results in energy waste. Based on the specific circumstances, we take various measures to eliminate operational deviations and bring the water pump back to operate in its high-efficiency range. 4. Customized and specially designed to eliminate unnecessary power consumption. When carrying out engineering design, design institutes generally do not perform precise calculations regarding the flow rate requirements of each water pump or the pipeline resistance; instead, they rely on analogical estimates, which are relatively conservative to ensure safety and reliability. In fact, even if a design institute were to attempt to calculate the required parameters, it would not be possible to achieve high accuracy, as the calculation process itself involves many vague empirical formulas and empirical coefficients. When the rated parameters of a water pump do not match the actual requirements, it is just as awkward and unsightly as a tall and thin person wearing a pair of fat and short clothes. Tailoring to individual needs can eliminate this situation. Based on the actual operating conditions of the customers, we determine the specific parameters appropriately and design pumps tailored to those conditions, ensuring a good match between the pump’s capacity and the actual load. This improves operational efficiency and helps achieve energy savings. 5. Optimized combination of multiple pumps for overall system optimization: Through a matched and optimized design of the entire system, including motors, water pumps, transmission devices, speed control devices, piping networks, and working devices, rational scheduling is achieved to ensure economical operation, improve the overall efficiency of the system, and achieve energy savings. Specific measures include: properly configuring water pumps, scheduling energy-saving operations in accordance with changes in production load, in order to achieve energy savings ； Improve the operating efficiency of motors, etc ； Reasonable diversion and backflow ； Reasonable series and parallel operation of water pumps, etc. 6. Adopt speed regulation and energy-saving technologies (variable frequency speed control, permanent magnet speed regulator control, coupling speed control, etc.). 7. Precision casting, along with careful polishing, improves product quality and precision at the manufacturing stage, thereby enhancing efficiency. 8. The latest research findings on improving the efficiency of water pumps, successful experiences from various minor improvements, as well as various \"ad hoc\" solutions and \"secret recipes\" were extensively collected. These were then analyzed and evaluated, with some of them selected for further testing at significant cost. Through summarization and application, many unique insights were gained, thereby enhancing the technical level of energy-saving services. To achieve good energy-saving results, it is necessary to adopt different energy-saving technologies tailored to specific situations, and combine several effective measures for energy savings. Variable frequency speed control energy-saving technology was widely used in previous years, making significant contributions to energy savings in water pump systems; it is now widely recognized and accepted. However, it should be noted that it is not suitable for certain operating conditions, and the inverters themselves consume 3–5% of electricity. The use of advanced fluid dynamics theory to design and manufacture efficient impellers and high-performance water pumps for energy-saving upgrades is not common in Shandong Province; yet this is precisely our core technical strength and what sets us apart. We are the earliest, and likely the only, company in Shandong Province to conduct ongoing research on three-dimensional flow impeller technology, and to carry out energy-saving upgrades by replacing pumps with high-efficiency impellers. Original material; citation by peers is prohibited
This post was last edited by WSRYLONG on 2016-8-16 at 20:32. To give everyone a practical understanding of the effects of energy-saving upgrades, we are sharing several recent success stories from our company: 1. In one case, a company’s #qsn300-m9 double-suction pump was equipped with our specially designed high-efficiency impellers; as a result, with the same flow rate, the motor current dropped from 280A to 230A, resulting in an energy-saving rate of 17.8%. 2. In another case, a company’s #qsn250-m6 double-suction pump, after being fitted with these specialized high-efficiency impellers, experienced a slight increase in flow rate, while the motor current decreased from 223A to 153.8A, yielding an energy-saving rate of 30%； 3. A company carried out an expansion upgrade on its #qsn250-m9 double-suction pump; with the same valves and piping system, the flow rate increased from 490 cubic meters per hour to 560 cubic meters per hour, and the efficiency improved significantly. 4. The circulating water pump 24SH-9B of a certain chemical company has a flow rate of 2,800 cubic meters per hour, a head of 56 meters, and an electric motor with a power rating of 560 KW. It originally consumed 520 kWh of electricity per hour; after replacing it with our high-efficiency impeller, the electricity consumption dropped to 470 kWh per hour, resulting in a savings of 50 kWh. 5. A company replaced its OS350-510B double-suction pump with our energy-saving pumps, achieving an energy savings rate of 15%. 6. Another company replaced its 10sh-6A water pump with our energy-saving pumps; as a result, the current required for the same flow rate decreased from 145A to 105A, resulting in an energy savings rate of 27%. To dispel customers’ concerns about whether the energy-saving upgrades are truly effective, our company records parameters such as flow rate and current with the customers before the upgrades are carried out, and again after they are completed. By comparing these values while keeping the flow rate constant, we allow the customers to verify the results themselves, ensuring transparency and credibility. Our company will develop the technical solution; the customer does not need to pay a single penny before the renovation is completed. All energy-saving pumps, impellers, and other components are provided by our company, and we bear all related costs. In other words, our company will cover the expenses for the renovation first, and charges will only be made if the renovation is successful; no fees will be charged if it is not successful. For the clients we serve, we usually start by modifying one unit first, thereby gaining their trust and appreciation, and then proceed to modify several units. Designing and manufacturing high-efficiency water pumps or high-efficiency impellers to replace old ones is the main approach for energy-saving upgrades of water pumps. As an advanced technology for designing high-efficiency impellers, the three-dimensional flow impeller technology has been widely used in China’s impeller machinery industry, playing a crucial role in the energy-saving transformation of water pumps; it is attracting increasing attention and being increasingly promoted for use. Implementation method for the technical renovation project of three-dimensional flow impellers: Based on the actual operating conditions of the user’s water pumps, and with the goal of fully meeting those operational requirements, this approach utilizes the theory of full three-dimensional flow involving jets and wakes. Design software such as PCAD and CFD is employed, along with the extensive experience accumulated by senior engineers, to carry out comprehensive optimization. High-efficiency three-dimensional flow impellers that can be interchanged are then redesigned and manufactured; these impellers can be installed directly within the original pump casing. No changes are required to the existing equipment foundation, motors, pipelines, etc. The installation process is simple and fast, the project is safe and easy to implement, and it offers significant energy-saving benefits. It can thus be considered the preferred solution for energy-saving renovations of water pumps. The total amount of the energy-saving service fee we charge is determined by taking into account factors such as the complexity of the project, the amount of investment required, the size of the water pumps, the extent of energy savings, and electricity prices. The amount varies depending on the specific circumstances, but it generally does not exceed the amount saved in electricity costs over 10 months. In other words, customers are ensured to save more in electricity costs within one year than the total amount of service fees they pay; there is a surplus left after the service fees are paid for that year. Compared to the electricity costs incurred before the renovation, the cost of the energy-saving renovation services did not impose any additional burden on the customer; on the contrary, the customer was able to save that amount of money in the same year, and even earn a profit as well. Once this service fee is paid, no further charges will be incurred. The energy-saving equipment provided by our company, as well as the energy savings it generates, all belong to the customer, who will continue to benefit from them in the long term. Customers only experience success, not failure – true zero risk, zero investment, and it saves time, effort, and money. Based in Zibo and serving the entire Shandong region, our company is eager to work together with pump users who place emphasis on energy savings and reduced consumption.
The business of energy-saving upgrades for water pumps holds great potential, and companies are called on to actively engage in it.