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Hi all,
I'm new to RE as well as this field. However, I'm going to do the instrumentation to evaluate the COP & Refrigeration Capacity of a domestic heat pump (3kW cooling/1.5kW heating). Could someone please explain about the instrumentation & data that I need for the calculations?
I'm getting confused as I have to do all the new things in a very short time.
Thanks in advance :)
Quote:
Originally Posted by Uni
I dont use Wikipedia often but it may answer your questions.
http://en.wikipedia.org/wiki/Coefficient_of_performance
COP is only a ratio between energy in and energy out.
The higher the energy out for the cost of the energy in = higher COP.
Cheers taz
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I think the COP of this unit will be a negative value ;)Quote:
Originally Posted by Uni
Hi Uni have a look at this and try searching GOOGLE its where i got this:eek:Quote:
Originally Posted by Uni
http://www.winfridge.com/HSU-notes.html
regards Norm
Hi Uni
U can use temperature measurement and pressure gages to Calculate the COP and refrigerant capacity.
Noori
Thanks for your quick responses.
I am a student learning about instrumentation. I chopped the AC down and installed all the following stuffs:
- Wet&dry bulb thermocouples at Evaporator (Indoor) Air Inlet & Outlet
- Anemometer at the Evaporator
- Pressure transducers + thermocouples to measure all the pressures and temperatures (evap in/out, cond in/out, suction/discharge, compressor shell)
- Data logger & software
- Nothing to measure mass flow rate
:confused:
So far, I have tried the charge tuning test. This helped me a lot to gain a better understanding about the system behavior. Now I want to move on to the COP & Capacity test.
Generally said,
C.O.P.= heat transferred/electricity input
Electricity input can be measured by a Watt-meter, so I have it installed already.
1. How do we measure the heat transferred?
2. Is there any other practical method to do this?
by using wet/dry bulb evap in/out temp and air flow (cube/hour) for example
Someone used calorimeters, etc. which I do not understand.
Please everyone, be more detailed. I'm really interested in this field :)
Exactly that! You need entering air wet and dry bulb temperature (or dry bulb temperature and relative humidity) and leaving air wet and dry bulb temperature (or dry bulb temperature and relative humidity). Applying that to Mollier chart you should find enthalpy of entering and leaving air and you only need air density and air flow to calculate sensible and latent heat of that air in measure of time.Quote:
Originally Posted by Uni
Yo could easily calculate that with numerous versions Mollier chart software or by doing your own calculations.
Hi Nike123,
don't you mean pschrometric chart? ;)Quote:
Applying that to Mollier chart
Sorry, I mean Mollier diagram.;)Quote:
Originally Posted by Tony
The Mollier diagram is a variant of the psychrometric chart. A move from the Mollier diagram to the psychrometric chart is explained here.Quote:
The Mollier Diagram :
The Mollier diagram, also called the ix diagram, is based on the relationship between heat content and water vapour content of air. The heat, or energy, content is difficult to measure directly, so the diagram is cunningly distorted to give the illusion of being based on the relationship between temperature and relative humidity and water vapour content. Temperature is easy to measure, relative humidity is considered by some people to be easy to measure and so the diagram is transformed into a useful tool.
Thanks, Nike123. I will try to get it done bu the next test. :)