Pump Technology Overview

First, the outline   Description

Historically, pump power loss and pump maintenance have been two major concerns for users. Loss of power leads to increased costs and maintenance of the pump during operation is always a headache for the user. Undoubtedly, the technological changes in two areas, including improving pump efficiency and reducing pump maintenance cost, have become the driving forces behind the development of pump technology. Based on the analysis of the recent development of pump technology, this paper reveals the technical characteristics of pump efficiency improvement, the reason why inverter drive, intelligent pump and pump system are widely used, and introduces the application of electronic components and the efforts made by Europe and the United States for the pump standard.

Second, improve the efficiency of pump technology

In 1995, the European pump, the European Association of pump manufacturing industry has established an energy-saving projects, began to focus on energy-saving research. In the meantime, the American Hydraulics Society (HI) and the American Pump Industry and Trade Association have assisted the U.S. Department of Energy in preparation for the production of video footage of pump and pump system energy savings.

Later, HI formed the Life Cycle Cost (LCC) Committee for Pump Products to promote the concept of life cycle costs for pumps and pump systems to pump users, manufacturers and engineers. For most pumps, one of the most important factors in LCC is power loss, so the LCC study has been formulated as a project that is energy-efficient with Euro pumps.

On a secondary basis, pump manufacturers worldwide are re-engineering research and development that is designed to increase pump efficiency and reduce pump power losses during operation. It is noteworthy that the pump is already a mature product, so the possibility of simply increasing the pump efficiency is small. However, research in this area to improve pump efficiency losses is very promising. Some manufacturers use NASA's non-metallic materials or carbon to plug the gaps in pump operation, improving pump efficiency. Such as the pump impeller and the inner ring of the pump gap, the gap between the middle bushing and so on.

Some countries are also quietly studying and trying to improve the quality of the flow path inside the pump. The smoother the shell surface, the smaller the water resistance. Thus increasing the efficiency of the pump.

Composites are comparable to many metals and can be machined to create a smooth surface. The blades of the impeller are machined into different geometries and assembled to the impeller. As a result, design engineers do not have to consider the surface roughness of the pump housing, center-shift or other casting problems. Composites can replace copper-tin alloy (bronze) and 316 stainless steel for brine or corrosive fluids. However, in non-abrasive, non-corrosive fluids, such as water purification, composites still do not have the advantage of competing with cast steel.

Third, frequency drive

In most countries, variable frequency drives (VFDs) are used more often in large pumps that require precise flow control, speed change, or long-term operation for high power losses.

1. Application areas

(1) Commercial Construction Matches VFD to air conditioning systems Closed loop pump water for cooling water in tall buildings.

(2) Pipeline industry In order to save energy in the pump pipeline industry, many countries use VFD. In the pipeline industry to use a large number of large pumps (power up to 10000 horsepower), so the amount of VFD is also very large.

(3) Centrifugal pumps Centrifugal pumps employ a movable shaft design that results in the first critical speed being above the maximum operating speed; also resulting in a reduced output speed of the VFD approaching the pump's other critical speeds. But sometimes there is a problem of vibration that is not sure, but finding the problem will be solved.

(4) In addition, a large number of VFDs are used in the electrical, food processing, water and wastewater treatment industries; a small amount of VFD is used in the pharmaceutical, chemical and refining industries. Pumps, while not central to these areas, play a crucial role. These industries use more small pumps than large ones, and they can use the regulator to control the flow rate instead of a variable-speed energy-saving small pump.

2. main feature

(1) Energy Savings A large number of VFDs are used in the water treatment and wastewater industry, saving energy when VFDs are used to change the flow output, which saves energy by using VFDs rather than switching off and starting a separate pump.

(2) Convenient When a single pump shutdown and start method requires a large number of pumps when the flow rate is small, only a certain number of pumps are required to use the variable speed pump method and the water hammer caused when the pump is turned off is avoided.

(3) Special Features Using VFD in food processing allows for the participation or process control of multiple fluids. In the electrical industry, VFD is used to regulate the speed of the boiler feed pump. As the load decreases and steam decreases, the drive of the motor or main turbine generator shaft can utilize VFD to adjust the boiler speed of the boiler feed pump to match the needs of the system and save energy. Sometimes separated steam turbines are used to drive boiler feed pumps and to change pump speed and flow output.

3. Other features

The VFD replaces flow control valves and monitoring instrumentation for precise flow control. VFD control pump speed changes in order to achieve pump output pressure or output flow control.

VFD can make the pump steady start, to avoid the pump at the beginning of full speed start, a sudden increase in flow, resulting in water hammer phenomenon. At the same time, reduce the impact of the fluid and mechanical pressure, reducing system fatigue, saving the cost of the motor, increasing the life of the pump.

4 . new development

In recent years it has become very common for VFDs to be used as components in positive drive systems for positive displacement pumps. Its function is equivalent to a process controller controlling the output of a positive displacement pump.

four,            Smart Pump

Intelligent pump is a new product, its concept varies from person to person, we talk about the smart pump is the use of instrumentation testing equipment feedback field signal to the intelligent pump analysis system, after analysis, determine, analyze the system gives the pump is And how to make a fault.

Because monitoring equipment and pump operation are closely linked, monitoring equipment becomes crucial to pump users. The pump manager needs to know what the mean time between failures (MTBF) is for a given pump run in order to schedule MTOBs and repair and replace worn and damaged parts in time.

HI has written articles that list 14 ways to monitor centrifugal pumps. They are power, temperature, corrosion status, leak detection, pressure, vibration, lubrication analysis, shaft condition, pre-installation hydrostatic test and design review. Each mode of effective monitoring can prevent and detect pump failure.

As the testing equipment and intelligent pump analysis equipment is very expensive, so the overall development of smart pumps slow. In general, monitoring equipment is used only for very large pumps and very important processes.

Several pump manufacturers around the world offer smart pump equipment for boiler feed pump control in the electrical industry. There is no steam cycle without a boiler feed pump. For example, a 500MW, 2400PSI power plant would require two 12,000 horsepower pumps. It is very important to monitor the operation of the pump.

Like the pipeline industry, smart pump equipment needs to control oversize pumps and very important processes. Suppliers of decarbonization and descaling pumps and multi-stage pumps are equipped with smart pumps for the same reasons.

The existing smart pump system can help users to extend pump failure interval, failure analysis can help determine the cost of maintenance. Of course, the price will drop as smart pumps become more widely available.

Five, electronic applications

In recent years, electronic technology has played a key role in the development and revolution of science and technology. In pumping and pumping systems, electronic technology is gaining more and more widespread use. Pump testing and pump diagnostics systems and communications between the two require electronic technology. No electronic components, the use of variable frequency drive pump with system equipment or energy simply can not be achieved.

High-pressure pump lubrication system is a very complex system, using a wide range of electronic devices to complete the accurate operation.

Before the boiler feed water pump needs to be preheated, heat flow balanced, the pump rotor to normal rotation. Electronic components are used to control the system to ensure the safe operation of large pumps.

The proportioning pump and the metering pump use the electronic technology to complete the fluid joining process and achieve the result expected by the user. For example, in the drinking water into the chlorine, the ratio pump and metering pumps are not completely independent work, they need electronic components, no electronic components, the entire system is unable to complete the work.

In short, the pump industry is increasingly dependent on electronics. Pump manufacturers need to be able to create a complete pump system independently, and each subsystem requires electronic components.

Sixth, the pump system

In the Middle East, parts of the Far East, Africa and Latin America, water treatment and wastewater treatment projects require pump manufacturers to create a complete pump package. This includes piping, valves, start-up and measuring equipment. Some areas, such as Venezuela, even require pump suppliers to do construction and municipal works.

Pump users around the world want pump suppliers to complete all of their subsystems and keep pump systems safe and stable. Subsystems include monitoring systems, variable speed control, flow or process control, preheating systems, lubrication control and more. The world trend is that users prefer to buy the entire pump system rather than just a pump.

The purpose of a user purchasing a pump system is out of the desire of a pump supplier to fully account for the system and pump requirements. Users want the pump supplier to make a warranty or repair on every pump subsystem, taking responsibility for the pump's positive system and not just a pump.

In some developing countries, there is a lack of engineers who assemble systems and test systems, so pump suppliers must have their own technicians on-site operations, which is why pump systems have evolved.

Now, suppliers can provide subsystems such as monitoring instruments, diagnostic equipment, electronic controls, preheat control and lubrication control systems. Not only are these subsystems guaranteed by the pump manufacturer, but they are also designed and supplied by the customer so that the user is more comfortable buying them.

Once the pump in operation there is a problem, the user only to find the pump supplier to solve the problem, since the pump supplier is completely responsible for the pump system, then find out the problem by him and solve them is appropriate.

Seven, the standard pump

Europe and the United States have a wide range of pump business association. The pump division with a large market share has become the local representative of the association. The association has built-in institutions that publish new standards or modify existing ones. Europe has the International Organization for Standardization (ISO), the United States has the United States National Standards Institute (ANSI) and the American Standards Association (ASA).

European pump and HI reached an agreement unified pump standard. In February 1996, the two organizations signed a mutual cooperation agreement. The agreement stipulates that in order to be beneficial to the common interests of both parties, the two organizations should enhance understanding and long-term cooperation, maintain the relationship between manufacturers and the members of the association, maintain technical exchanges with pump users, share pump statistics worldwide, establish the Atlantic Ocean Cross-Strait and cross-border business dealings.