Strategies to optimize pump system efficiency and life cycle performance

Process pumps are one of the largest energy consumption in the plant and increasing the efficiency of the pumping system is a new shortcut for reducing plant operating costs. The ever-changing business climate is prompting businesses to make many changes to their traditional operating practices. Market globalization, demand adjustments, and stakeholder interests all require factories to find new ways to further reduce their production costs. In recent years, although enterprises are increasingly using information technology (IT) to improve productivity, such as enterprise resource planning and supply chain management. But while the factory is equipping its business systems with the latest IT tools, they are still using outdated and inefficient motor- driven pumping systems to run the production process. Today, inefficient motor-driven pumping systems are a weak link in the production process management. More specifically, the efficiency of a motor-driven pump system can play an important role in optimizing the production process. Although it is often overlooked, using technologies that increase its efficiency can dramatically reduce energy consumption and reduce maintenance and raw material consumption. For example: Pumped liquids typically consume the largest portion of the energy consumed by industrial motors throughout the pulp and paper lines and in the process. Optimizing the efficiency of the pumping system increases the stability of the pump and process, while achieving 20% ​​to 50% improvement potential for energy savings and reduced maintenance costs. In addition to hindering the overall increase in production efficiency, inefficient pumping performance can result in reduced product quality, lost production time, indirect damage to equipment, and excessive maintenance costs. Larger is not always better The efficiency of the entire plant is often influenced by the correct selection, installation and maintenance of the pump system. Standard industrial practices often increase the size of the pump to ensure that it meets the needs of the process peak. In the past, this practice was accepted when the paper mill had a continual order need for all its forestry-based products. But today, things are different. The globalization of markets has led directly to excess reserves of pulp products and excess capacity. This change in situation determines that oversized selection of pumps should be re-examined. In 1996, "a Finnish Technical Research Center released a report entitled centrifugal pump performance diagnostics expert analysis report" shows: by analyzing 20 factories pump 1690, found that the average efficiency of the pump is less than 40%, and 10% of the pump Operating efficiency is less than 10%. Pump oversizing and throttling control valves were identified as the two main causes of excessive energy consumption. Strategy to improve pump efficiency The initial purchase price of a process pump is typically less than 15% of its life cycle cost (LCC). A 50 horsepower pump has a life cycle cost of installation, operation, maintenance and system downtime that is several times the original purchase cost. In general, energy costs can account for about 30% of pump life cycle costs and up to 40% for maintenance costs. If used for more than 20 years, the cost of energy and maintenance will exceed 10 times the initial purchase cost, and this part of the cost can be significantly reduced by increasing efficiency. Pump system performance is affected by the following factors Individual efficiency of the pump and its system components The entire system design Pump control effect · Drive part of the efficiency · Appropriate maintenance cycle The factory's system assessment helps identify and quantify the best solution to improve pumping system efficiency. The most potential system to improve the efficiency of the program is as follows Improve motor efficiency through replacement and product upgrades The best match each part selection and load requirements Reduce the load on the motor by improving process and system design • Use pump speed adjustment instead of throttling control valve or return device Also, the following features indicate potential for system efficiency improvements when performing pump system evaluation: Throttle valves, normally open return lines, all pumps in a multi-pump parallel system are always running, and pump operation that is constant during a batch process , The existence of cavitation noise. Table 1: Control Valve and Speed ​​Adjustment Under the same flow conditions Intelligent flow control The development and application of frequency converters (VFDs), and in particular the application of intelligent control drives for pumping control, have led to major changes in the operating practices of control valves as a flow master. In the past, frequency converters (VFDs) were used to reduce energy consumption or conventional control is not good. In fact, the Intelligent Pumping System is an optimized solution for pumping systems with intelligent software integrated into the drive's microprocessor chip. Smart drives keep the pump running close to its best efficiency point (BEF) and protect the pump from mechanical damage when the pump runs off its best efficiency point. The latest research shows that pump operation near the best efficiency point Pump efficiency and operational reliability have been dramatically improved. Table 1 compares the control valve differential pressure, pump speed and efficiency fluctuations under different flow needs. The intelligent variable frequency drive allows the pump to run at the optimum impeller diameter and at lower speeds, which further increases the reliability of the pump and results in a considerable improvement in mean time between failure (MTBF). In new projects, the purchase and installation costs of control valves are saved, followed by savings in energy and maintenance costs, which can result in a significant reduction in the total life cycle cost of the pumping system. Once put into use, intelligent variable frequency drive technology can provide the following changes Automatic adjustment to adapt to process changes Automatic adjustment to adapt to changes in the pump system Protect the pump during system failure Provide real-time status monitoring Sensor and control software already deployed Intelligent pumping systems provide smooth drive and capacity changes, tighter control over continued production, and potential problems with the system when it has no negative impact on product quality or process operation More rapid diagnosis. As shown in Figure 1. Figure 1: Schematic diagram of the pump system, comparing the difference between a traditional pumping system and an intelligent pumping system. Energy saving As shown in Table 2, in the pulp and paper industry, pumps consume most of the motor energy. In fact, the concentrated energy consumption of process pumps makes them the main choice for saving energy and reducing consumption. Table 2: Pumping system is a source of concentrated energy. Different types of process pump mechanical design will consider efficient operation. In practice, the design is designed to determine the size of the pump to operate at the point of maximum efficiency under normal operating conditions. However, process requirements and throughput requirements often change significantly over time. As a result, finding a constant speed pump to run at the best efficiency point is like "shooting a moving target." Flow pumps in all of the plant's rotating equipment have the greatest potential for energy savings. By intelligently controlling the motor speed in real time, the intelligent pumping system adjusts energy usage as needed. Through the motor speed adjustment to meet the precise process requirements, and to avoid unnecessary energy consumption. Case studies show that up to 50% or more of the energy can be saved by optimizing pump performance. In addition, consuming too much energy on a normal speed pump is not used on the pumped liquid, but rather on the pump body and results in reduced pump system reliability. In addition to reduced energy consumption, the biggest advantage of an intelligent pumping system is the resolution and elimination of recurrent operational problems encountered by the plant's production, maintenance and engineering departments. Under normal circumstances, the highest failure rate of equipment in the centrifugal pump, the seal leak is one of the longest production downtime and maintenance costs of the highest failure. Pump system optimization helps to reduce unplanned parking and increase production. Pump system optimization helps to reduce unplanned parking and increase production. Improve equipment management A successful, predictable maintenance strategy for motor-driven pumping systems should include the use of on-line monitoring of intelligent pumping systems. Related monitoring information can be passed to the device management software integrated into the process control system or sent to the CMMS for alarm and history archiving. In the past, equipment information needs to be manually collected and archived, or frequently by hand into the computer maintenance management system. After years of development, automated equipment condition monitoring systems have matured, especially on large rotating equipment such as turbines, but are less used in predictive maintenance. Factories generally still rely on established predictive overhauls and emergency remedial repairs. By developing predictive maintenance capabilities, the maintenance department can continuously check and update equipment status information in real time. Real-time analysis of equipment data provides practical information to plan maintenance work, which is more effective than scheduling a scheduled time since last parking maintenance. The main advantages over planned maintenance are extended continuous operation, increased operational mobility and, more importantly, reduced maintenance. Figure 2 shows that the cost of a predictive maintenance approach is significantly reduced over the established preventive maintenance approach or remedial maintenance approach. Figure 2: Predictive maintenance saves money. With predictive maintenance, tangible device status information replaces speculation about the status of the device, allowing the plant to begin planning and scheduling time after it receives a forecast of device status drops. Factories no longer have to be forced to repair damaged equipment. As a result, maintenance operations that used to rely primarily on human history such as equipment history, experience, and intuition, have now become a scientific process for fault identification. in conclusion In the past, the manufacturing industry used process instrumentation to measure physical and chemical variables in processes. Although sensors were also used to monitor equipment such as pumps, compressors and other rotating equipment, it was limited to some very expensive equipment. Today, with the growth of intelligent devices and digital communications, traditional process control and equipment management functions are gradually integrated into the process management system. The emergence of smart pumps has become a decisive step in the further development of process management. After adding intelligence, not only control but also pump protection and condition monitoring on the same variable frequency drive platform. Despite its energy-saving and operational advantages, the factory faces many obstacles when it comes to implementing new technologies that increase efficiency in motor-driven pumping systems. This is primarily due to the lack of knowledge of managers, engineers, and distributors of new technologies and solutions to improve the performance of the pump system. After learning about new technologies, taking risks by changing the long-established production practices often delays decision-making and project execution. In addition, inefficient staffing in the maintenance, production and engineering departments also limits the evaluation and application of new technologies. Given these constraints, there is a general perception in the factory sector that "do not change if the equipment is not damaged." On the other hand, there are also supplier-side factors that have contradictory motives for improving system efficiency and implementation. For example, pump distributors are more willing to sell more pumps to meet the growing needs of their customers, rather than to advise customers on how to meet increased production through more efficient pump operations. Interestingly, many end-users are willing to continue making purchase decisions based on their original investment , even as distributors discover opportunities and explain potential benefits, rather than investing more to achieve long-term savings. In order to be able to get the many benefits of pump system optimization, end users, manufacturers and distributors, as well as design engineers, must work together. A comprehensive assessment at the plant level provides an effective way to justify projects to identify the best opportunities for improvement. Once implemented, a better application will be discovered, which provides a stable development channel for major projects to achieve the goal of sustainable development.