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Peter_1
26-09-2004, 11:38 AM
What do you think of this?
http://www.gaslok.biz/

I have my doubts.

Peter

chemi-cool
26-09-2004, 04:55 PM
Hi Peter.

It looks that with all the sophisticated electronics and sensors, by the time all the refrigerant escaped, it will tell you that the system is short of gas :D

I dont like it.

Chemi :)

electricstuff
26-09-2004, 10:27 PM
"....sense the quality of the flow of liquid refrigerant..."
What the hell is "quality of the flow....."

shogun7
27-09-2004, 01:45 AM
Peter, I believe a good service maintenance program and a competent engineer is a much better alternative. This reminds me of when they got rid on real people to answer the phones and intoduced us to pushing buttons ugh! :mad:

Stav
09-09-2005, 09:52 AM
sounds like an electronic sight glass to me. Interesting, but what's wrong with a traditional sight glass, set of gauges, and thermometers to see what's happening?

Argus
09-09-2005, 10:36 AM
This device has been in preparation in one form or another for some years now and seems to be constantly evolving.

The idea is very sound, being an unattended monitor that looks at the quality (meaning liquid - vapour composition) in an apparently full liquid line.
It is an ?electronic? sight glass that, if I recall, uses ultra sound to detect changes in the patterns of vapour entrained in liquid flow. The technology is in use in other fields, I believe. The intention of looking at the operating patterns is to eliminate condition changes resulting from, say TEV adjustment, stabilising temperature changes after a defrost etc. that could mislead typical electronic sight glasses.

If it does what it says it detects changes that are otherwise imperceptible before they become significant in increased energy consumption.

I seem to recall David Peall presenting this to the British Refrigeration Association a couple of years ago.
Why not ring him up and talk to him before you write it off? He's a very approachable bloke, as I remember.

As he?s an Ozzie, wait until the dust on the Ashes has settled!

.
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US Iceman
09-09-2005, 01:55 PM
After reading the material on the website my initial assumption is this sounds like an ultrasonic detector. This technology is being used to measure/monitor liquid levels or flow rates.

The ultrasonic flow meters I have used are a little tricky. Their accuracy capability can be very good to poor depending on their location on the piping.

The flow meters have to be several pipe diameters from any discontinuity (elbows, valves, etc.). Anything that disturbs the flow stream in the piping, can lead to erratic results.

The electronic site-glasses (clamp on, or surface mount sensors) can detect the quality of the refrigerant (gas bubbles in the liquid). However, they cannot tell you the percentage of, or measure the amount of gas in the liquid stream.

The developer may have some software built into the device that helps to interpret the data, which may make it more responsive and useful than an electronic site-glass.

My question is, how does it respond to changes in system operation? Say you have an air-cooled system that cycles the condenser fans to maintain head pressure. When the fans turn on with increasing head pressure, the liquid line may have a few bubbles in it. Is the system short on charge, or is operating normally?

Argus
09-09-2005, 03:08 PM
My question is, how does it respond to changes in system operation? Say you have an air-cooled system that cycles the condenser fans to maintain head pressure. When the fans turn on with increasing head pressure, the liquid line may have a few bubbles in it. Is the system short on charge, or is operating normally?

Why not ask the inventor? His contact details are on his web site.

The problems with operation variables on this type of device are obvious. It seems to me that this type may dovetail with other monitoring systems, rather than relying on only one monitor, especially on unmanned sites......

The advantages of any kind of non-invasive detection system are that in Europe we are on the verge of mandatory leakage inspection ranging in frequency from annually for 3 kg contained to monthly for over 300 kg. The same rules say that whre a montoring instalation is present, the inspection intervals can be doubled. This will most certainly be cost effective for large central plant in terms of inspection costs.
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US Iceman
09-09-2005, 03:32 PM
Hi Argus,

I agree with your logic.

Some redundancy in monitoring systems is a prudent concept. I would say this falls into a category of "layers-of-protection". The same principle is applied in large refrigeration systems.

Example: A mechanical float switch for primary shutdown responsibility for the compressors, with a capacitance probe for alarm annunciation with rising liquid levels.

This goes into the design philosophy that should be used during the concept stages for the overall system operation. This thought process could also be extended to include hazardous operations analysis to force the issue of reviewing any/all potential refrigerant releases.

I believe these measures are cost effective in containing the refrigerants and would recommend a similar approach applied to any system.

The larger system charges should be using using multiple detection methods as a normal practice in my opinion.

The US EPA has similar rules for refrigerant release prevention on our side of the pond.

Argus
09-09-2005, 03:41 PM
Hi Argus,


The US EPA has similar rules for refrigerant release prevention on our side of the pond.

Is it law?

The coming EU rules will introduce mandatory periodic checks on all equipment over 3 kg, with a GWP over 15.
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US Iceman
09-09-2005, 04:50 PM
YES.

To my knowledge we do not have the periodic checks required, but there are requirements to control the refrigerant usage.

This is the document title for this requirement.

"Compliance Guidance For Industrial Process Refrigeration Leak Repair Regulations Under Section 608 Of The Clean Air Act"

They have a method for determining the average leak rate and directions on what is acceptable, or not.

This is several hundred pages of paper.

Steve Wright
09-09-2005, 05:44 PM
I think the best detection method is direct leak detection there are several good units out there.

One we use a lot looks at 16 zones. If designed, installed ,and serviced properly they do a great job on small leaks and spills.

If a lot of refrigerant is at stake I think it's the way to go.

If you need more data let me know.

Steve

chillyhamster
09-09-2005, 08:22 PM
Dave Peall and gaslok have gone back to Oz, never to return:rolleyes:
System looked for the difference in a full sightglass and a range of bubble size and duration to indicate refrigerant loss within a system. Emerson of USA are also peddling the technology:rolleyes: