imola – june, 19 2013 - 01 hvac & water application note

Imola – June, 19 2013 - 01

HVAC & WATERApplication note

HVAC & WATER

HVAC

Heating, Ventilation and Air-Conditioning (HVAC) is all about efficiency:

•Room temperatures need to be maintained at optimum levels to achieve the best occupant confort.

•It is essential to consider how hit targets in reducing costs and carbon dioxide (CO2) levels.

HVAC & WATER

WATER - PUMP

An operating pump will normally consume more power than the hydraulic circuit requires and it is usually positioned in unconfortable site:

•It is essential to consider how achieve targets in reducing power consumption, costs and CO2 levels.

•Maintenance time and costs need to be reduced in order to avoid long plant standstill.

HVAC & WATER - Why VFD flow control?

HVAC & WATER systems are designed to operate under the most extreme conditions

and, HVAC typically, in the “worst case” situations that the system will encounter

Most of the time they have excess capacity


Problems of traditional flow control

•Low system efficiency•Difficult in regulation •Electromechanical stress•Noise due to mechanical resonance•High starting current•Big supply cable section or cable number•Maintenance cost and time


Reducing the capacity of the systems when full capacity is not required provides significant energy

savings without sacrificing system performance

VFD Flow control

HVAC & WATER

Return Fan

Supply Fan

Primary cold/ChilledWater Pumps

CondensorWater Pump

Cooling Tower Fans Secondary Hot/ChilledWater Pumps

HVAC & WATER - Characteristic

0 100 200 300 400 500 600

Flow

0

5

10

15

20

25

30

35

40

45

50

Pre

ssur

e

Pump Curve

System Curve

OperatingPoint

HVAC & WATER - Traditional throttling flow control

0 100 200 300 400 500 600

Flow

0

5

10

15

20

25

30

35

40

45

50

Pre

ssur

e Power

Flowx

Pressure

New Power

required

WASTED Power

Powerto load

P

Pressuredrop

HVAC & WATER - VFD flow control

Cooling

Coil

Primary

Chilled WaterPump

SecondaryChill Water

Pump

DifferentialPressureSensor

Secondary

Chilled Water

Pump Drive

ChillerAir

Duct

Cooling

Coil

AirDuct

Cooling

Coil

AirDuct

Cooling

Coil

AirDuct

VFD avoids the pressure dropby controlling the speedof the pump


0 100 200 300 400 500 600

Flow

0

5

10

15

20

25

30

35

40

45

50

Pre

ssur

e

P

«VFD c.» Power

required

«Throttlecontrol» Power

required


Proportional Integral Derivative function (PID)

The sum of these three actions is used to adjust the process via a control element such as the position of a control valve or the power supply of a heating element.

PID controllers attempts to correct the error between a measured process variable and a desired set-point by calculation and then outputting a corrective action that can adjust the process accordingly.


Controller

DetectorFeedback value

Controlled Variable

Actuating Signal

Motorfreq.

Comparator

Σ SystemSet point

0-10VDC or 4-20mA signal

The target value or Set-point has to be set by user. This could be the desired pressure, flow, temperature, vacuum, etc.

E.g.: this reference is the measure of how much fluid is required to be sent to the wastewater pipeline.

Feedback value

Set point

Motor & PumpVSD

Transducer

Pump outlet


The standard «ready-to-install» IP54 SINUS PENTA solution is particularly suited to HVAC & WATER

applications:

High degree of protection against dust and water spraysAbility to mount without additional enclosures and ventilationPID functions for automatic controlBuilt-in EMC filterOnboard communications allows control and monitoring


The standard «ready-to-install» IP54 SINUS PENTA solution is particularly suited to HVAC &

WATER applications:

Extensive I/O with internal comparator functionsFire Mode function for extended operation in critical periodsSpeed Search function to start on a rotating loadReal Time Clock (RTC) function to adjust confort to demands that change over the weekMultipump functionRobustness and reliability

HVAC - SINUS PENTA advantages

AIR HANDLER

Reduce energy costs and CO2 emissionsVariable torque load characteristics use less energy as speed is reduced

Reduce supply demandDrives reduce motor starting current up to 10 times

Reduce noise in buildingsAirflow noise decreases by eliminating starts/stops and optimising flow rates

Reduce shock and vibrationDrive avoids running at speed near system resonant frequency and provides controlled acceleration

Increased life of motor beltsDrives provide low torque starts reducing stress on belts, pulleys and keys


WATER CONDENSER CHILLER

Reduce energy consumptionProvide improved efficiency and reduce energy requirements

Reduce CO2 emissionsDue to the energy savings

Provide continuous operationRestart a spinning motor after momentary power loss


COOLING TOWER FAN

Energy savings and reduce energy costsMotor use less energy as speed is reduced

Reduce CO2 emissionsDue to the reduce energy consumption

Reduce maintenance requirements and reduce operating costsRobust constructions and energy efficient

WATER - SINUS PENTA advantages

PUMPReduce energy costs and CO2 emissionsVariable torque load characteristics use less energy as speed is reduced

Reduce demand chargesDrives reduce motor starting current up to 10 times

Control of pressure of flow using PIDThe drive can optimize the pressure flow, and its linearity variations, with a single pressure transducer

Wide power range for different pump sizesNetwork communicationsSupport all major protocols

Prevention of water hammer, pipe stress, valve, pump seals and cavitationExtends the life of the entire system

WATER - MULTIPUMP application overview

• Controls a multi-pump pumping system (up to 5 pumps)

• One pump is the speed-controlled master and the other pumps are variable speed or fixed speed slaves

• Multi-Master mode

• Connection using I/O or Modbus

• Automatic balancing of operating hours of all pump sets

• Elimination of water hammer

WATER - MULTIPUMP: Fixed Speed Slaves (FSS)

The Master pump operates to ensure the system fine-tuning. The slave pumps are started up/stopped based on the criteria below:

1.Percentage of the working power required for the master pump (allowing optimum performance of the plant).

2.Maximum allowable adjusting error.

3.Maximum difference among the working time of each available pump.

The power ratio of the connected pumps must meet one of the following requirements:1.All pumps must have the same power ratings.2.The connected pumps can have different power ratings, provided that each pump with the greatest power rating is matched with lower-rated pumps that, if combined, have power ratings equal to or higher than the former pump.3.The power rating of the master pump must be higher than/equal to the power rating of the lower-rated pump.


Soft-Starter ASAB

Soft-Starter ASAB

Soft-Starter ASAB

Soft-Starter ASAB

Basic diagram for a fixed-speed plant including 4 slave devices and 1 MP Penta drive controlling the system in analog mode.

PENTA MULTIPUMP SOFTWARE

WATER - MULTIPUMP: Variable Speed Slaves (VSS)

The slave pumps and the master pump are started/stopped based on the following criteria:

1.Percentage of the working power required for the master pump (allowing optimum performance of the plant).

2.Maximum allowable adjusting error.

3.Maximum difference among the working time of each available pump.

All the connected pumps must have the same power ratings.


PENTA MULTIPUMP SOFTWARE

Modbus MASTER

MODBUS RTU

Modbus SLAVE

MULTIMASTER

FUNCTION

PENTA DRIVEPENTA DRIVE

The diagram above shows a configuration for a variable-speed multipump system, serial communications and Multimaster function.

PENTA DRIVE

HVAC & WATER: Variable Air Volume (VAV) Supply Fan

SupplyFan

HeatingCoil

CoolingCoil

ReliefAir Damper

OutsideAir Damper

ReturnAir Damper

PressureSensor

Supply Fan Drive

ReturnFan

ConditionedSpace

HVAC & WATER: Supply Fan - Temperature

ConditionedSpace

Supply Fan Drive

SupplyFan

T

T

HVAC & WATER: Supply Fan - Smoke Extraction

SupplyFan

ReliefAir Damper

OutsideAir Damper

ReturnAir Damper

SmokeSensor

Supply Fan Drive

ReturnFan

ConditionedSpace

Close thisdampe r

Reversethis fan

HVAC & WATER: Stairwell Pressurization

Fan Drive

Fan

Tp

Fire mode function

HVAC & WATER: Parking Garage Ventilation Fan

COSensor

Vent. Fan Drive

Vent.Fan

SmokeSensor

HVAC & WATER: Fume Hood Fan

Fume HoodFan Drive

Fan

HVAC & WATER: Cooling Tower Fan

TemperatureSensor

Cooling TowerFan Drive

CoolingTower Cells Chiller

CondenserWater Pump

HVAC & WATER: Condenser Water Pump

Flow Sensor

CoolingTower

Chiller

CondenserWaterPumpDrive

Strainer

HVAC & WATER: Examples

HVAC & WATER

Thank you

imola – june, 19 2013 - 01 hvac & water application note

Documents