Case Study: Replacement of Inefficient Chiller – Operational Savings in Chemical Industry
Energy efficiency in HVAC and refrigeration systems is vital for industries where cooling demand is continuous and utility costs are high. This case study from XYZ Company demonstrates how replacing an inefficient chiller compressor resulted in significant operational savings, improved performance, and immediate payback.
Background – Equipment and Industry
- Equipment: Refrigeration Chiller
- Industry/Sector: Chemical Manufacturing
- Process Heat Load: 100 TR (Tons of Refrigeration)
- Initial Condition:
- Compressor specific power consumption was 2.5 kW/TR.
- This indicated a very inefficient compressor compared to the expected 0.8–1.0 kW/TR for good systems.
Problem Identified – Inefficient Compressor
The existing inefficient compressor was consuming excessive energy due to a manufacturing defect.
- High specific power consumption meant higher electricity bills.
- Cooling performance was below industry standards.
- The plant required continuous chilled water, making inefficiency costly.
Practical Example: For a 100 TR load, the inefficient compressor consumed 250 kW, whereas a good compressor should consume only 80–100 kW.
Corrective Measure – Replacement with efficient Compressor
- Recommendation: Replace the inefficient compressor with a new efficient compressor.
- Implementation:
- The compressor manufacturer replaced the unit free of cost under warranty.
- A new efficient compressor was installed and tested.
- Result:
- Specific power consumption reduced to 1.0 kW/TR at motor input.
- Cooling efficiency improved dramatically.
Cost Benefit Analysis
- Type of Measure: Major Retrofit
- Annual Energy Savings: Significant reduction (estimated in tens of thousands of kWh annually).
- Actual Cost Savings: Substantial savings in electricity bills (Rs. value depends on tariff rates).
- Actual Investment: Nil – replacement was covered under warranty.
- Payback Period: Immediate – no capital investment required.
Practical Example: If electricity cost is Rs. 7/kWh, reducing compressor power from 250 kW to 100 kW saves 150 kW per hour. Over 6,000 operating hours annually, this equals 900,000 kWh saved, or Rs. 63 lakh/year in cost savings.
Key Learning – Importance of Efficient Chillers
- Energy Efficiency: Inefficient compressors drastically increase operating costs.
- Warranty Benefits: Timely identification of defects can lead to free replacements.
- Operational Reliability: Efficient chillers reduce downtime and improve process stability.
- Immediate Payback: Major retrofits under warranty can deliver instant financial benefits.
Conclusion
This case study highlights how replacing an inefficient chiller compressor can lead to massive energy savings and improved system performance. XYZ Company reduced its specific power consumption from 2.5 kW/TR to 1.0 kW/TR, saving thousands of kWh annually with zero investment thanks to warranty coverage.
