Landis + Gyr

Compressed air energy audit

Written By: Shane Egner Owner of Egnergy

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

Executive Summary

The purpose of this report is to convey the results of the compressed air energy study performed at Landis+Gyr’s Reynosa Mexico facility from Sunday May 25th through Thursday May 29th of 2014.

The compressed air system is operating at 33% efficiency with a potential for energy savings of over $19,000 Pesos annually and a total annual cost savings including maintenance of $23,224.75. This cost reduction can be achieved with a return on investment of less than one year.

 

Existing

 

 

System

New System

Annual KWH

268989.1

103958.4

Annual Cost (USD) @$.116/KWH

$31,253.58

$12,078.82

System Efficiency

33%

97%

Average Flow (CFM)

54.0

54.0

Average Power (KW)

26.7

11.9

Carbon Dioxide Equivalent (Metric

 

 

Tons)

185.0

71.0

Annual Maintenance Cost (USD)

$13,550.00

$9,500.00

 

 

 

Equipment Cost

$15,875.00

 

Energy Audit Cost

$3,000.00

 

Installation Cost

$3,000.00

 

Annual Energy Cost Savings

$19,174.75

 

Annual Maintenance Cost Savings

$4,050.00

 

Return On Investment (Years)

0.94

 

2

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

1:Introduction

Cost reduction is an essential part of a manufacturing facilities sustainability and continued success. This report shows in detail how the cost savings, return on investment calculations and data collection were performed.

2: Methodology

Compressed air flow meter:

The compressed air flow in SCFM (Standard Cubic Feet Per Minute) was measured using a CDI Meters 5400-20S flow meter (data sheet in figure 1). The flow meter was installed in the pipe between the compressed air system and the compressed air distribution system. This meter uses a loop powered 4-20 milliamp signal to transmit compressed air flow to the data logger. The flow is recorded one time per second in units of SCFM

Pressure Transducer:

The compressed air pressure was measured using an Ashcroft Pressure transducer part number G27M0205F2200#G-#4177 installed in at the inlet of the distribution system and in two locations in the distribution piping. The data sheet for the pressure transducer can be found in figure 2. The pressure transducer has a range of 0 – 200 PSIG with a corresponding meter output from 0 – 5 VDC. The pressure transducer is connected to the logger using a 12 VDC power supply for excitation voltage. Pressure is recorded every 1 second in units of PSI.

Compressor Power:

Compressor power was measured using a Veris Industries H8042-0300-2 power transducer. The power transducer monitored the incoming power of the compressor in KW and was recorded one time per second. The power transducer measures voltage and current and calculates power to be output to the data logger via a 4 – 20 mA signal. Data sheets for the H8042-0300-2 can be found in figure 3.

Data Logger:

The measurements for flow, pressure, and compressor power were recorded one time per second using two Onset UX120-006M. The data is read and graphed through Onset’s software called HOBOware.

3

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

3: Results

Compressed air leak rate: The leak rate of the compressed air system was calculated using the average flow of compressed air into the distribution system during a time when there was no production in the plant (5/25/2014 1:00 PM – 4:00 PM). The leak rate of the system was found to be 46.8 SCFM. This leak rate represents a large portion of the overall compressed air consumption of the facility, but is the equivalent of flow through an¼” inorificesize. Thebetwleenak 1/8”rate andforthis size of facility is acceptable. One

opportunity to lower the leak rate is to lower overall plant pressure. Lowering plant pressure by 10 PSI will lower the existing leak rate by around 9%.

Compressed air consumption: The actual consumption of compressed air by the plant was calculated by subtracting the leak rate from the overall average compressed air flow rate. The average compressed air flow rate while the plant was operating was found to be 54.2 SCFM. This means that the compressed air flow necessary for production is 7.5 SCFM.

Compressed air system efficiency: The compressed air system efficiency was calculated by comparing the rated CFM/KW of the operating compressor and comparing it to the actual CFM/KW of the compressed air system. The nameplate flow rating for this compressor is 364 CFM with a power rating of 59.7 KW. The data collected shows an average flow rating of 54.2 CFM with an average power of 26.7 KW. This gives us an ideal ratio of 6.1 CFM/KW and an actual ratio of 2.0 CFM/KW. The ratio of actual to ideal gives system efficiency, which is 32.8%.

4

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

Graph 1

Compressor idle time: The average cycle time for the compressor is around 3 minutes. The compressor is loaded (producing air) for approximately 30 seconds and unloaded for approximately 2 minutes 30 seconds. The motor still spins while the compressor is unloaded and consumes around 30% of the rated power of the compressor. The compressor runs unloaded until the load pressure set point is reached. The compressor must run in this matter due to the fact that there is a maximum number of starts and stops an induction motor can perform in an hour without causing damage to the motor. Graph 1 above shows the three full compressor cycles and is representative of the entire week of data.

Dryer: The compressed air dryer that was operating during the study is a 600 CFM cycling type dryer. This dryer consumes 4.82 KW and was taken into account in the energy calculations.

Lower plant pressure: One opportunity for savings for Landis+Gyr is to reduce the pressure in the distribution system to the minimum possible without affecting production. The minimum plant pressure during the study was found to be 88 PSI. It is reasonable to assume that 88 PSI is a good starting point for plant pressure, but it may be able to be lowered beyond that. A pressure control valve is included as part of the equipment in the implementation. This control valve will allow the pressure on the supply side to cycle between the set points of the compressor and maintain a relatively constant (+/- 1 PSI) pressure within the distribution system. This will reduce the leak load of the plant because there will be less force to push the air through the leaks.

5

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

Online/offline curve:

The curve above is a representation of online/offline controlled compressor efficiency. The curve is used by first calculating the ratio of compressed air storage to maximum compressed air flow. This ratio is used to determine which line the compressor efficiency falls on. The capacity of compressed air storage for Landis+Gyr is 800 gallons while the compressor capacity is 364 CFM. This gives a gal/cfm ratio of approximately two. It is fairly obvious from the graph above that a ratio for gal/cfm of two is less than desirable. The proposed compressor will have a gal/cfm ratio of 10. The addition of a new, correctly sized, compressor will bring the efficiency of the system to its maximum.

6

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

System Drawings

Existing system:

Proposed system:

Pressure differential: Another parameter that was examined was the differential in pressure between the compressor room and the facility. This differential pressure is important because if it is large it can cause an inflated pressure at the compressor room to compensate for the pressure drop in the distribution system. The pressure differential at the Landis+Gyr facility is not only acceptable it is desirable. The maximum pressure drop in the system is less than 2 PSI.

Carbon Footprint: The carbon footprint of the Reynosa Landis+Gyr facility can be reduced by the Carbon Dioxide equivalent of 114 Metric Tons.

*This number generated by the Environmental Protection Agency’s website www.epa.gov

7

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

4: Conclusions

The main conclusion that can be drawn from the compressed air efficiency study is that the compressed air consumption of the plant has shrunk considerably from the time the compressed air system was installed. If there were no leaks in the distribution system the plant could operate on a small 5 HP compressor.

5: Recommendations

It is recommended that Landis+Gyr install a smaller, correctly sized compressor and a pressure regulator to regulate pressure within the distribution system. By following these recommendations the facility will save over $23,000 per year.

8

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

CDI 5400

FLOWMETER FOR COMPRESSED-AIR

SYSTEMS Rev. 2.0

Easy to install

No moving parts

Digital display

Milliamp and pulse outputs

No calibration or setup required

Complete flowmeter in one package

Optional RS-485 output for net- working

Housing rotates to suit vertical or horizontal installation

The CDI 5400 clamps onto a pipe, with two flow-sensing probes projecting into the pipe through 3/16-in. drilled holes. It seals directly to the pipe; no cutting or welding is required for installation. Because each flowmeter is made and calibrated for a specific size of pipe, the digital display indicates flow directly, with no setup or adjustment.

The meter measures flow by maintaining one probe warmer than the other. It calculates the mass velocity from the amount of heat required, and then calculates the flow on the basis of pipe area. The flow rate, in scfm, is shown on a large, four-digit display; a 4-20 mA output and a pulse output permit remote display, totalizing and data collection.

AVAILABLE SIZES

Nom

Calibrated

Model No. for

Model No. for

range b

Size a

Sch 40 Steel

Type L Copper

(scfm)

2 in.

4

- 400

5400-20S

5400-20Cc

2.5 in.

5

- 500

5400-25S

5400-25C

3 in.

12

- 1200

5400-30S

5400-30Cc

4 in.

20

- 2000

5400-40S

5400-40Cc

5 in.

20

- 2500

5400-50S

--

6 in.

50

- 5000

5400-60S

--

8 in.

100 - 6000

5400-80S

--

SPECIFICATIONS

Accuracy:

5 percent of reading plus one percent of full scale at air temperatures between 40 and 120 degrees Fahrenheit

Accuracy, extended range:

7 percent of reading from rated full scale to 150 percent of calibrated range, at air temperatures between 40 and 120 degrees Fahrenheit

Fluids:

Compressed air and nitrogen

Operating pressure:

200 psig maximum on Sch. 40 steel and on Type L copper below three inch; consult CDI for other materials and higher pressures.

Input power:

250 mA at 18 to 24 Vdc

Output resistance:

400 Ohms max.

Materials exposed to measured fluid:

Stainless steel, gold, thermal epoxy and Viton (seal)

Ring material:

Aluminum

(a)Meters are also available for several sizes of Aluminum pipe. For metering smaller pipe sizes, please see our Series 5200 flowmeters.

(b)Accuracy will be reduced when flow is outside of the specified range. Milliamp scale ranges differ.

(c)Flowmeters for 2”, 3, and 4” copper have smaller calibrated ranges.

Display:

Four-digit LED display

Response time:

One second to 63 percent of final value

US Patent 6,802,21

Figure 1

9

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

Model G2 Pressure Transducer

Cable

Connection

Hirschmann

Connection

Metri-Pack

Connection

Flying Lead

Connection

LOOK FOR THIS

AGENCY MARK ON

OUR PRODUCTS

APPLICATONS

The G2 pressure transducer combines performance with value to meet the demanding needs of the original equip- ment manufacturer in applications found in:

Off-road Equipment

Construction Machinery

Performance Racing

Railroad/Transportation

Compressor Control

HVAC and Refrigeration

Agricultural Implements

Process Automation and Control

Hydraulic & Pneumatic Sensing

Pump Monitoring

FEATURES

1% Total Error Band Accuracy

Broad Temperature Capability

All-welded pressure construction

High EMI/RFI rating

Ranges 30 psi through 20,000 psi

IP 67 Ingress rating

Diagnostic rails

The Ashcroft® Type G2pressure transducer has been specifically designed with the high volume OEM in mind.

A ±1% Total Error Band accuracy is accom- plished by marrying a high performance ASIC to a very stable, field proven polysilicon thin film pressure sensor. The sensor is electron beam welded to a pressure fitting of stainless steel, which provides excellent overpressure capability and outstanding durability in the presence of shock and vibration.

The circuitry is held within an internal cage and housed in an enclosure of reinforced Nylon.

TOTAL ERROR BAND (TEB)

Error limits of all points (0-100% of range)

 

2.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1.5%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

of span)

1.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.5%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Error

-0.5%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-1.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-1.5%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-2.0%

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-60

-40

-20

0

20

40

60

80

100

120

140

 

 

Ambient Temperature (C)

 

 

 

Pos Error Limit

 

 

 

 

 

 

 

 

Neg Error Limit

 

All specifications are subject to change without notice.

 

All sales subject to standard terms and conditions.

BULLETIN G2

© 2013 Ashcroft Inc., Rev. 08/13

PERFORMANCE SPECIFICATIONS

Ref. Condition 21°C ±1°C (72°F ±2°F)

Accuracy:

Total Error Band includes combined effects of temper- ature, non-linearity (Terminal Point Method), hysteresis, non repeatabilty, zero offset and span setting errors

±1% of Span: From –20 to 85ºC (–4 to 185ºF)

±1.5% of Span: From –40 to –20ºC (–40 to –4ºF) ±1.5% of Span: From 85 to 125ºC (185 to 257ºF)

Note: Static accuracy ±0.25% of span BFSL (Best Fit Straight Line Method); includes non-linearity, hysteresis and non-repeatable effects at reference temperature 72°F (21°C)

Stability: Less than ±0.25% span/year Durability: Tested to 50 million cycles

ENVIRONMENTAL SPECIFICATIONS

Temperature:

 

 

Compensated

–40 to 125°C

(–40 to 257°F)

Operating

–40 to 125°C

(–40 to 257°F)

Storage

–40 to 125°C

(–40 to 257°F)

Humidity: 0 to 100% R.H., no effect

FUNCTIONAL SPECIFICATIONS

Select from over 25 pressure ranges starting at 30 psi and running through 20,000 psi gauge. Compound (vacuum & pressure) ranges are also available, see “To Order” on back.

Overpressure (F.S.):

Proof

Burst

750 psi & below

200%

F.S. 1000% F.S.

1500 psi

200%

F.S.

500% F.S.

3000 psi

200%

F.S.

500% F.S.

5000 psi

150%

F.S.

500% F.S.

7500 psi

120%

F.S.

500% F.S.

10,000 psi

120%

F.S.

240% F.S.

20,000 psi

120%

F.S.

240% F.S.

Vibration: Random vibration (20 g) over tempera- ture range (–40° to 125°C). Exceeds typical MIL. STD. requirements

Shock: 100gs, 6 ms

Drop Test: Withstands 1 meter on concrete 3 axis

Response Time: Less than 1 msec

Warm-up Time: Less than 500 msec typical Position Effect: Less than ±0.01% span, typical

ELECTRICAL SPECIFICATIONS

Output Signals Available:

Supply

 

 

Voltage Output

Excitation

Current

0-5 Vdc, 3 wire

9-36 Vdc

5mA

0-10 Vdc, 3 wire

14-36 Vdc

5mA

1-5 Vdc, 3 wire

9-36 Vdc

4mA

1-6 Vdc, 3 wire

9-36 Vdc

4mA

0.5-4.5Vdc, 3 wire

9-36Vdc

4mA

Ratiometric Output:

 

 

0.5-4.5 Vdc, 3 wire

5 Vdc ±0.5 Vdc

3.5mA

Current Output:

 

 

4-20mA, 2 wire

9-36 Vdc

 

Reverse Polarity & Miswired Protected: Yes Insulation Breakdown Voltage: 100 Vac

Insulation Resistance: Greater than 100 megohms at 100 Vdc

CE Marked: Per DoC

EMC Directive 2004/108/EC

IEC/EN 61326-1:Edition 1.0 Industrial

IEC/EN 61326-2-3:Edition 1.0 Annex BB Industrial PED Directive

Ashcroft Inc., 250 East Main Street, Stratford, CT 06614 USA Tel: 203-385-0648 • Fax: 203-385-0408

email: info@ashcroft.com • www.ashcroft.com

Figure 2

10

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

Figure 3

11

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

 

 

 

 

 

 

 

 

 

Compressor Room Pressure

 

 

 

 

 

 

Flow (CFM)

 

Plant Pressure (PSIG)

 

(PSIG)

 

Compressor Power (KW)

 

 

 

 

Std

 

 

 

Std

 

 

 

Std

 

 

 

Std

Date

Max

Min

Avg

Dev

Max

Min

Avg

Dev

Max

Min

Avg

Dev

Max

Min

Avg

Dev

5/25/14

159.9

22.5

49.3

35.2

102.2

87.7

94.6

4.1

102.5

87.9

94.8

4.1

49.8

21.6

27.5

8.7

5/26/14

175.7

22.7

52.7

36.5

102.3

87.5

94.5

4.1

102.4

86.8

94.7

4.1

152.3

19.3

26.6

9.4

5/27/14

166.9

23.8

52.8

36.5

102.3

0.0

94.1

6.7

102.3

87.8

94.7

4.1

57.3

17.9

26.2

9.2

5/28/14

166.7

24.4

57.3

37.6

102.3

87.3

94.5

4.1

102.4

87.7

94.8

4.1

49.7

18.7

26.8

9.4

5/29/14

162.2

0.0

57.2

37.8

102.4

0.0

93.3

11.6

102.4

21.4

94.6

5.3

153.4

0.0

26.6

10.6

Full

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Week

175.7

22.5

54.2

37.0

102.4

87.3

94.2

6.5

102.5

86.8

94.7

4.3

175.7

17.9

26.6

9.5

12

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

13

Landis+Gyr Compressed system cost reduction

Egnergy

19718 Ranch Meadow

San Antonio, TX 78258

210-560-6568

UP6-20-125 Rotary Screw Air Compressor

Technical Information:

Capacity:

83cfm @ 125psig

Maximum Operating Pressure:

125psig

Weight:

1186 lbs.

Connection Size: 1.0” NPT

Dimensions (L x W x H): 51” x 36” x 41”

Additional Engineering Data available upon request.

Image for reference only

The design of the Ingersoll Rand Rotary screw air compressor combines a high efficiency integrated compression module, simple diagnostics, quiet operation and a compact footprint. Options include integrated air treatment and advanced controls.

These features deliver unparalleled reliability, ease of operation and flexibility in placement and application. The addition of the integrated dryer increases the life and enhances performance of down stream tools and equipment.

Key Features included as Standard:

 

 

x

230-460V

ODP Motor / FV Starter

x

Low Sound Enclosure (68 dba)

x

Load / No

Load with Auto Start/Stop

x

Ultra Coolant

Controls

14

Landis+Gyr Compressed system cost reduction