Presentation on theme: "Welcome Using Variable Speed Drives to Save Energy. Dan Reilly June 22 nd 2010."— Presentation transcript:
Welcome Using Variable Speed Drives to Save Energy. Dan Reilly June 22 nd 2010
Welcome (Lunch is now less than 90 min away!!) Emerson Industrial Automation Overview Industry/Application Expertise Variable Torque Loads –Pump Control –Fan Control –Energy Savings Calculator AC Drives Benefits –Variable Frequency drive product features Product Solutions Overview Summary Agenda
Saving Energy with VFDs Over 50% of the electric energy consumed in the U.S. is used by electric motors. Electric motors & systems account for almost 64% of manufacturing sector electricity consumption. This translates into $30 Billion annual energy cost. A heavily-used motor may cost six to ten times its purchase price to operate per year.
Lifetime Costs of a 100HP Motor **Over a 10 Year expected life cycle. **Purchase price represents less than 1% of the lifetime cost.
What does a Variable Frequency Drive Do?What does a Variable Frequency Drive Do? Q: What is motor control? A: Motor control is the means by which a motor’s speed, torque, or position is determined in some form of a controlled manner. Q: What is a drive? A: A drive is a device that converts electrical energy into rotary mechanical motion via a motor shaft. Q: Why use a drive? A: Lower costs through: –Energy savings –Reduced overhead Better Performance: –Increased productivity –Higher throughput Motor Control Basics
What Differentiates Industrial VFDs? Exceptional motor control Virtually any type of motor and feedback device Control Techniques performance delivers higher throughput and quality Best product retrofit solutions on the market ANY Motor AC MotorDC MotorServo Motor
Industry & Applications Aerospace Agriculture Asphalt and Cement Automated Assembly Building Materials Chemical Centrifuges Converting Crane and Hoist Energy Generation Extruders Fiber and Wire Food and Beverage Heavy Moveable Structures Life Sciences Medical Devices Mixing Lumber and Timber Pharmaceutical Plastics and Rubber Pumps Semiconductor Specialty Machines Stage and Theatre Textiles Water/Wastewater
Introduction Of all the applications for Variable Speed Control, Centrifugal Pumps and Fans offer the greatest potential for Energy Savings due to the nature of the load. These loads are defined as Variable Torque. Variable Toque means that the load torque requirement varies (increases) with speed.
Volume Flow is proportional to fan speed Pressure proportional to the speed squared Power used proportional to the speed cubed Audible noise proportional to speed to 5th Power. Fan Affinity Laws
Variable Torque Loads Load requires much lower torque at low speeds than at high speeds. Fan and Pump loads obey the AFFINITY LAWS. Horsepower varies approximately as the cube of the speed, and the torque varies as the square of the speed. If the motor speed is reduced 20%, motor horsepower is reduced by a cubic relationship (0.8 x 0.8 x 0.8) = 51%. If the speed is reduced significantly and often the opportunity for energy savings is great.
Variable Torque Load Characteristics NOTE: At 80% Speed (Flow) the theoretical Power consumption is only 50% of rated.
VFDs and Pumps Common applications in Industrial Process control, Building HVAC systems and Water/Wastewater. – Chilled Water Pumps – Condensed Water Pumps – Building Supply Pumps – Chemical Dosing Pumps
VFDs & Pumps Typically sized for maximum flow Systems typically operate at less than designed levels Flow control is normally achieved using an output control valve Measured in GPM (this is what we want to control)
VFDs and Pumps Control Pump Speed for process control Regulate Flow Save Energy Payback periods of 8 months to 2 years depending on: – Duty Cycle – Energy Costs
Typical Fixed Speed System DUTY REQUIRED CONTROL VALVE POWER INPUT
Variable Speed Drive System DUTY REQUIRED VFD Control Valve Eliminated or Locked Open POWER INPUT
VFDs and Pumps Provide significant energy savings when: – Pumps are operated at lower flow rates – Existing system has bypass control – System has low static head – Local electricity costs are high – Pump has steep design curve
VFDs and Pumps Additional Benefits Elimination of expensive valves and valve controls Reduces power surges and stress associated with across the line starting Provides accurate flow control Longer Pump and seal life Reduced wear Less noise A VFD is potentially the BEST way to regulate flow and save energy
VFDs & Fans Common applications in Industrial Process control and Building HVAC systems. – ID (Induced Draft) and FD (Forced Draft) Fans – VAV (Variable Air Volume) Fan – Condenser Fans – Fume Hoods – Cooling Towers
VFDs &Fans Typically sized for maximum flow Systems typically operate at less than designed levels Flow control is normally achieved using either an output damper or inlet guide vanes
Typical Fixed Speed System DUTY REQUIRED OUTPUT DAMPER POWER INPUT
Variable Speed Drive System DUTY REQUIRED VFD Damper Eliminated or Locked Open POWER INPUT
Owens Corning 500HP fans. 3 x 500HP fans on fiber glass production line. Changed from damper to variable speed control. VSD Installed cost - approx $390,000. Energy savings - $225,000 per year Payback period - 1 year 9 months. Increased equipment life. Reduced maintenance / noise / vibration $225k on the bottom line every year after payback!
Variable (Dynamic) Volts/Hz - Maximizes Energy Savings - Is selectable for application flexibility Independent PID For stand alone process control of flow or pressure Skip Frequencies For bypassing of mechanical resonance's Variable Frequency Drives Fan and Pump Features
Supply Dip Ride through - The drive can automatically ride through momentary power dips by reducing speed and then returning to set speed when the supply recovers without tripping. Supply Voltage Load Speed Time Variable Frequency Drives Fan and Pump Key Features and Benefits PROBLEM:
Skip Frequencies For bypassing of mechanical resonance's reduces wear on the system Set Point Actual Drive Frequency Skip Frequency 1Skip Frequency 2 Actual Drive Frequency jumps past critical points Variable Frequency Drives Fan and Pump Key Features and Benefits PROBLEM:
Independent PID loops built into the VFD For stand alone process control of flow or pressure or level No need for external controller, save $$$ Reference Feedback Output PIDPID Drive Frequency Level Set Point Level Transducer Variable Frequency Drives Fan and Pump Key Features and Benefits PROBLEM:
Variable Speed Drive Additional Benefits Electrical Supply Benefits = more cost savings – Good power factor – approx. Unity. – Reduced peak amps surcharges Comfort – Reduced fan / pump noise – Reduce water hammer and air duct rumble – No light dimming on start up Maintenance – Less stress on mechanical equipment – Controllable via a DeltaV, PLC or fieldbus (Ethernet, DeviceNet, Profibus, Modbus, & others) reduces the need for process adjustments
Energy Metering and Operating Cost Indicator - Power consumed, operating costs per hour, power up time log and maintenance flags are all standard features providing free Asset Management tools. 24 ENERGY kWh Variable Frequency Drives Fan and Pump Key Features and Benefits PROBLEM:
Variable Frequency Drives World Class AC Drives are: – Specifically suited to Centrifugal fans and pumps applications – Easy to set up and install – Feature packed for maximum flexibility – High Performance – Going to save you money!
Saving Energy with VFDs Look for: – Centrifugal fans and pumps – Pump systems with a low static head – Duty cycle 40hrs / week. – Significant installed over-capacity. Variable Frequency Drives can: – Assist with payback analysis – Provide Fan and Pump drives, motors, systems, fieldbus interfaces, fan/pump sequencing software.
Saving Energy with VFDs LOOK FOR “DUTY CYCLE”: What if I don’t know what my duty cycle needs to be? How long does the motor need to run at 100% speed? How long does the motor need to run at 50% speed? How long does the motor need to run at a minimum to keep the process running?
Control Techniques A Market Leader in Intelligent Drives & Drive Systems Founded in 1973 1,500 Employees Worldwide Key Advantages –Technology Leader –Best Service and Support –Best Value Solutions Provider –Global Manufacturing facilities (USA, UK, China, Mexico) –Manufacture ~400,000 drives annually