Abstract

Several types of smart products are already available today in both the commercial and industrial marketplace. The pump industry has been behind the times in incorporating computer technology to operate, control and protect pumps and their systems. Smart pumping systems can match pump output exactly to system conditions and can detect and protect the pump and system against unusual operating conditions. Through the use of a smart variable speed controller these systems can significantly reduce pump-operating costs by eliminating the use of energy consuming control valves. The value of smart pumping systems to the user is in reduced life cycle costs. All of the major components of life cycle cost such as operating cost, maintenance cost, initial cost and installation cost should be evaluated when comparing smart systems to conventional systems.

Introduction

All types of products, which exercise some type of control over their function, are rapidly making their way into the marketplace. On the commercial side there is smart automobiles and more recently, smart appliances have also begun to appear. On the industrial side there is smart instrumentation, smart control valves and smart motors. The pump industry is behind the times in incorporating the use of computer technology to operate, control and protect pumps and their systems. Certainly over the past few decades-significant progress has been made in the areas of pump hydraulics, mechanical design and applications through the use of computerized tools such as computational fluid dynamics (CFD) and finite element analysis (FEA). However, only recently have manufacturers begun to develop "smart" pumps which incorporate microprocessors as part of their normal function.

A smart pumping system by definition must be capable of knowing when to adjust itself to system changes without manual intervention. The system must also be fault tolerant. Fault tolerance enables the system to recognize and safeguard itself from operating under conditions that may reduce its life. Adverse conditions such as dry running, operation against a closed suction or discharge valve and cavitation must all be recognized and reacted to before damage occurs. The system must also be capable of understanding when the system transient or unusual operating condition has cleared; thereby allowing normal pump operation to resume.

A "smart" pumping system consists of a pump, variable speed drive, instrumentation, microprocessor and special software. The pump can be any standard centrifugal pump fitted with instrumentation to measure suction pressure, suction temperature, discharge pressure and pump flow. All of the hydraulic characteristics of the pump, fluid characteristics, user control parameters, alarm settings and pump control software reside on the microprocessor of the smart controller. The pump control software enables the controller to sense pump and process conditions and react accordingly. These systems can be designed to maintain constant values of speed, capacity, pressure, level or pH and can be controlled either locally or through a distributive control system (DCS).

The value to the customer in using Smart-Pumping Systems is reduced life cycle costs. The major components of life cycle cost are:

  • Operating Cost

  • Maintenance Cost

  • Initial Cost

  • Installation Cost

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