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Anonymous Poster #1

COP of Refrigeration System used in Trains

06/13/2016 6:55 AM

Vapor compression refrigeration systems are used to provide air conditioning to trains. Can you please tell practically what COP we get in such refrigeration systems.

If anybody could tell specifically of air conditioned trains in INDIA it could be very much useful

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#1

Re: COP of refrigeration system used in trains

06/13/2016 7:47 AM

"Indian Railways Technical Department. How may I direct your call, please?"

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#2

Re: COP of refrigeration system used in trains

06/13/2016 8:12 AM

The manufacturer or Type Approval Authority will be able to tell you about the Conformity of Production.

IF COP has another meaning for you, then you you should specify it in your question.

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#3
In reply to #2

Re: COP of refrigeration system used in trains

06/13/2016 8:14 AM

A curse on TLAs!

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#8
In reply to #3

Re: COP of refrigeration system used in trains

06/13/2016 10:19 PM

I'll brook no criticism of the Tilgate Lake Association

:-)

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#5
In reply to #2

Re: COP of refrigeration system used in trains

06/13/2016 12:09 PM

I recognized it as Clean Out of Place, hence, makes no sense.

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#6
In reply to #5

Re: COP of refrigeration system used in trains

06/13/2016 2:13 PM

I get 'Can't Operate Phone' from it myself.

So is this a real engineering question or one of those 'They told me the system is running at optimum efficiency and settings yet everyone here is sweating and all around miserable because the system is undersized and can't keep up and I need a way to prove it other than obvious visual confirmation and opinion of customers.' type issues.

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#4

Re: COP of refrigeration system used in trains

06/13/2016 11:12 AM

Have some info...

http://www.railway-technology.com/contractors/hvac/lloyd-electric-and-engineering/

http://www.indianrailways.gov.in/

http://www.nwrail.com/nwre_products/hvac-index.html

http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=5366326&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D5366326

"The air cycle refrigeration system used in Chinese train air conditioning engineering is investigated. The effects of possible parameters affecting system performance are examined through sensitive analysis of the thermodynamic model. The results show that, the pressure ratio should be in the range of 2-2.5, the COP will be in the range of 1-1.2, and the cold air distribution system can be used. To increase the COP, higher efficiencies of compressors, expanders and heat exchangers are expected.

http://www.sciencedirect.com/science/article/pii/S2211381911000051

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#7

Re: COP of Refrigeration System used in Trains

06/13/2016 6:00 PM

1 hp ≈ 2454 Btu/h; 1 kW ≈ 3412 Btu/h.

Find out the cooling capacity of the unit or system in Btu/h. Divide that by the power input as computed from either factor given above. The result is coefficient of performance (COP).

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#13
In reply to #7

Re: COP of Refrigeration System used in Trains

09/03/2016 1:04 PM

Dear Mr. Tornado,

I have a different view in your reply.

What you have given is " 1 hp ≈ 2454 Btu/hr; or 1 kW (or 1.33 H.P.) ≈ 3412 Btu/hr., This figure relates to conversion factor between Heat Energy and Mechanical Power. Interms of K.Cal. it is 860 K.Cal/ KW.Hr.

For refregeration - the unit used is tonner (or one tonne of refregeration) and it is defined as 12,000 Btu/Hr. is one tonne of Refregeration. In other words if a room is fitted with 1 Tonne AC Machine (whether window type or split type) it will remove 12,000 Btu of Heat in one hour.

Pl. let me know your comment.

Thanks,

DHAYANANDHAN.S

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#14
In reply to #13

Re: COP of Refrigeration System used in Trains

09/03/2016 3:17 PM

True but irrelevant. To compute COP, one must use factors of identical units. Furthermore, tonne is not the only unit for refrigeration capacity. Btu/h and kW are sometimes used. Also there is metric tonne of refrigeration (based on 2204 lb of water versus the 2000 lb for a ton of refrigeration.

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#9

Re: COP of Refrigeration System used in Trains

06/13/2016 10:33 PM

All refrigeration systems use the "vapour compression" principle, . . in the home, office factory or train. The COP of such systems varies from about 1.5 to 4 depending on temperature conditions.

In India, being a 'warmer place', . . the COP is likely to be running 1.5 - 2.

Tour little beer cooler that you take to the picnic and operates in you car from the cigaret lighter, opertes on teh Peltier principle and its COP is very low . . . . often lower than 1.

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#10
In reply to #9

Re: COP of Refrigeration System used in Trains

06/13/2016 11:51 PM

Did you say beer? Let us know where and when. Picnic is fine too.

Beer from India I hear is also not to bad, if you like a spicy Indian Pale Ale.

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#11

Re: COP of Refrigeration System used in Trains

06/14/2016 5:38 AM

The use of acronyms is getting out of hand and it must stop..ASAP!(Quote from a former boss.)

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#12
In reply to #11

Re: COP of Refrigeration System used in Trains

06/15/2016 7:20 PM

Had to deal with an inspector on an assembly line who would make up acronyms on the fly and expect everyone to know what he was saying. After a meeting with he and I along with our respective supervisors an "Official Defect Abbreviation List" was released. Could not wait till the next day when, sure enough, a "new" acronym appeared. Immediately I marked it NOODAL and returned the machine to him. His response, "NOODAL, what the hell is NOODAL"? My reply, "Not On Official Defect Abbreviation List"! As I had anticipated, he stormed off to his boss's office where he got the response, "What did you expect"? Never saw another "new" acronym after that day. Mission accomplished!

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