WAYS TO OPTIMIZE CHILLER PLANT
Optimization is done by monitoring and controlling equipments like Chillers, pumps, cooling towers and AHUs etc. in association with control
system. It also includes monitoring of chilled water flow, pressure in and out across chiller, condenser water flow, pressure in and out across
condenser, air velocity at cooling tower fan, temperature and relative humidity at inlet of cooling tower, ambient temperature and RH,
temperature and RH at the air-conditioned rooms, conductivity and PH of water in chilled water and cooling water, temperature
across Chiller, temperature across condenser, temperature and pressure across AHUs and FCUs, flow across AHUs and FCUs and Power of all
the major power consuming equipment’s. Then Control system builds all the coordination which enable access to chillers internal data.
This data is used as input data to design efficient chiller control program.
ENERGY EFFICIENCY OPPORTUNITIES
1. APPROPRIATE CONTROL OF CHILLER WATER PUMPS AND BYPASS CONTROL VALVE
Chiller water pumps maintain a specific pressure in chilled water piping through VFD and control system. To maintain minimum chilled
water flow system requires chilled water bypass control valve. By sequencing chiller water pumps we can operate them effectively.
2. CONDENSER LOOP
It is less prominent when compared to chiller and chilled water control. Most chiller plants operate their condenser at fixed temperature.
In new chillers it is possible to provide cool condenser water, which benefits chiller operation by less power consumption. Control
strategy which reduces condensing
water temperature when chillers are operating at part load conditions improves chillers performance at that load, which leads to
energy and cost savings. This strategy is known as Condenser Water Temperature Reset.
3. CONTROL OF COOLING TOWER FAN MOTORS
In cooling tower additional energy savings can be attained by operating 2 cooling towers at 50% speed instead of 1 at 100% speed as
per laws of pump affinity.
CONCLUSION
• Understand parameters that affect chiller plant and overall system performance
• Optimize operation through equipment selection and control sequences to deliver CHW to all loads as efficiently as possible throughout
the year
• Right Algorithms in Automatic controls covering Chillers, cooling towers and their pumps & fans are pivotal for HVAC energy performance.
• Chiller plant operated manually cannot go much closer to Energy Optimisation possible.