JCI San Antonio Compressed air energy audit

Written By: Shane Egner

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

Executive Summary

The purpose of this report is to convey the results of the compressed air energy study performed at Johnson Control’s San Antonio Battery facility from Monday March 9th through Friday March 20th of 2015.

The main focus for the study was to look at the dew point of the compressed air entering the distribution system and find potential for energy savings.

 

Existing

New

 

System

System

Annual KWH

1,476,238

1,306,470

Annual Cost (USD) @$.06/KWH

$88,574

$78,388

Average Flow (CFM)

929

929

Maximum Flow (CFM)

1162

1162

Average Power (HP)

235

208

Minimum Pressure

~90 PSI

~90 PSI

 

 

 

Energy Savings Potential

$10,186

 

2

JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

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.

**Power cost calculations are base on an electrical cost of $0.06/KWhr**

2: Methodology

Compressed air flow and dew point meter:

The compressed air flow in SCFM (Standard Cubic Feet Per Minute) was measured using a VP Instruments Differential Pressure flow meter. The flow meter was installed in the pipe between the compressed air dryers and the mist eliminator filter (before the flow control valve). This meter measures both pressure and flow and transmits this data to the logging unit via Modbus. Dew Point was measured using a Michell Instruments SF-52 dew point transmitter. The dew point was transmitted to the logger using a 4-20 mA signal.

Compressor Power:

Compressor power was measured using a Veris Industries E50C2 power meter. The power transducer monitors 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 modbus signal.

Data Loggers:

The measurements for flow, pressure, and compressor power were recorded one time per second using two Onset UX120-006M and one LogicBeach IL80. The data is read and graphed through Onset’s software called HOBOware.

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3: Results

Compressed air consumption:

No Production:

The graph below is a representation of compressed air flow, pressure, and the power to generate the flow for Saturday 3/14. There was no production occurring during this period of time. The average flow of the system was 776 SCFM and the average power was 196 HP. This compressed air usage can be contributed mostly to leaks. It is strongly suggested that a leak study be performed and corrective actions taken to minimize the impact of leaks on JCI’s energy bill.

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

Compressed air consumption:

With Production:

The graphs below show the parameters recorded in the compressor room: Total Power, Flow, and Pressure. The average power during production was found to be 242 HP with an average flow of 958 SCFM. The maximum flow of the system was 1163 SCFM. The header pressure varied from 110 PSI to 68 PSI with an average of 98 PSI. The minimum pressure was likely due to a compressor shutting down and probably cannot support production. The minimum sustained header pressure during production was approximately 90 PSI and the compressors are set to operate at 115 PSI.

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

Dew Point:

The dew point in the compressed air system is less than desirable. The graph below shows system pressure, compressed air flow and dew point. The dewpoint more closely follows ambient air temperature rather than pressure or flow.

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

Opportunities:

Quality:

The first and most obvious opportunity with the compressed air system is quality. The dew point of the air is at a level where it is impossible to not have condensed moisture in the compressed air lines. The current configuration is also causing excessive pressure drop. This pressure drop occurs in the dryers. The recommendation of this report is to install two correctly sized compressed air dryers in parallel. This will ensure there is a back up dryer in case of breakdown or maintenance and will help to eliminate the excessive pressure drop the system is currently experiencing.

Efficiency:

The rule of thumb for increased pressure at the outlet of an air compressor is 1% per two PSI increase. The graph below shows the pressure in the wet tanks (or compressor outlet pressure) vs. the pressure of the air entering the plant. The average difference in pressure is 11 PSI or approximately 5.5% of the compressor power (around 13 HP). The graphs show the system can operate at a pressure of around 90 PSI. This represents a reduction in compressor power of 11.5% (around 27 HP). The goal for pressure drop is as little as is reasonably possible.

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

System Drawings

Existing system:

Proposed system:

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

4: Conclusions

With a few modifications to the piping and adding two new air dryers JCI San Antonio will have an efficient, redundant and reliable system.

5:Recommendations

1.Fix the leaks in the plant.

2.Install two new cycling refrigerated dryers

3.Re-pipe the system to have dryers running in parallel vs. series and more dry storage capacity than wet storage capacity

4.Remove the flow control valve from the system. The variable speed drive compressor can maintain plant pressure within a couple of PSI

5.Move filter to the inlet of the dryers

Daily Graphs:

3/14/2015

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3/15/2015

10

JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3/16/2015

3/17/2015

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JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

12

JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3/18/2015

13

JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3/19/2015

14

JCI San Antonio Battery Plant Compressed air system

Egnergy

3400 N McColl Suite F11

Mcallen, TX 78501

210-560-6568

3/20/2015

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JCI San Antonio Battery Plant Compressed air system