chiller power saving

Hi Guys,

I have a three chiller system that is water cooled with 3 cooling tower with VSD control. THere are three condenser water pump with common header and three chilled water pumps. THe chiller brand is TRANE. I have asked TRANE how information on ways that i can optimise the chiller but there have refused to provide this info saying only their controller can effectively optimise the chiller performance.


The PLC requires to control this chiller and optimise the system to save cost.

WHat are the ways to optimise the chiller ? Under what conditions should the second chiller cut in ets .. Where can i get information on how the PLC can control the chiller effectively.

Thanks.

Are you the registered member heng_swee?

And would this be the same system?

This chiller plant system is a constant volume chiller water flow system with bypass control. There are three chillers, chilled water pump, condenser water pump and cooling tower.

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Or this one?

Help! I need to represent a control system with a state diagrams.
Does anyone have any sample of state diagrams for a chiller or AHU system.

I have read up on how to built a state diagrams with the bubbles etc..
But i am having probelms creating one for a PLC control systems.
PLease help with any smaple of a actual system.

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Please SEARCH and review the CHILLER posts from last summer, I believe that you will find all your information covered there.

One of the posted comments recommended contacting the manufacturer. Since this obviously didn't work, try contacting a different manufacturer for assistance.

We can assist in providing a Traffic Light Signal to help indicate if the system is operating at peak efficiency, operating okay, or operating inefficiently.

(REF: On/Off, Flip/Flop, Traffic Lights)

Hi

I have the posts from last summer. This is a different problem from my previous posting. The PLC software requires to effective control the chiller so that it could operate at a lower cost with same efficency.

I need to know what are areas to condsider like if load has increase, should the second chiller cut in or should i adjust the cooling tower.

Thanks.

Best bet would probably be to adjust the cooling tower.

Rather then use variable drives, how about controlling valves to cut in or bypass some of the cooling tower.

A RTD could be hooked into an analog input to compare effected temperature with encountered efficiency perception. I know it can be done on GE with math functions, but would guess it could be done with AB and most other brands.

This is a reasonably complex problem. I started on a similar project for a large hospital last year, but I moved on to another project before I could finish it.

There are a number of variables that will be contributing to your running costs. What I suggest is that you think about the problem in terms of dollars. ie for every variable you can alter, there will be an associated incremental cost.

To find the best solution you then iteratively step through simulation of all the possible operating conditions that are valid for the current load/temperatures etc. Each iteration will have a total cost and one of them will be the lowest.

Start with a very simple model that includes only the most important variables and then as you become more confident, add more. With time you will develop a very good optimisation for your total plant, load and climate.

Thanks for the help.

It seem that it is difficult probem with no definite solutions.

hengswee said:

It seem that it is difficult probem with no definite solutions.

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That's the way it is on the fun problems!

Start with a simple diagram. Show the energy into the system, and the energy out of the system. Then show the fluid flows (air and water) into the system, and the flows out of the system. Add the sensors you will need to measure these flows. Develop simple equations that define the relationships between the energy flows, the fluid flows, and the measurements. By studying these relationships you can determine the parameters that will most influence the energy use, and then you concetrate first on the relationships with the most infuence.