×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

what does HIGH COMPRESSOR LIFT mean?

what does HIGH COMPRESSOR LIFT mean?

what does HIGH COMPRESSOR LIFT mean?

(OP)
what does HIGH COMPRESSOR LIFT mean?

I get alot of different explanations from different people and it is starting to become confusing.


please share insights

RE: what does HIGH COMPRESSOR LIFT mean?

Compressor lift is compressor pressure.

Lift = pressure

RE: what does HIGH COMPRESSOR LIFT mean?

I would say pressure difference to be more exact, suction and discharge.

People often talk about lift in the same sense as cycle work, power and energy.

RE: what does HIGH COMPRESSOR LIFT mean?

(OP)


some says its the difference of the evap and condensser temperature...???


 

RE: what does HIGH COMPRESSOR LIFT mean?

Therein lies the confusion.  Inside the saturation curve, the temperature at a given pressure is constant.  ie. Know the pressure, you know the temperature.  People often speak condensing/evaporating pressure and temperature in the same context.

Note that discharge temperature of the compressor is typically higher than the condensing temperature due to superheat.  The majority of the condenser coil is at the condensing temp tho.

RE: what does HIGH COMPRESSOR LIFT mean?

(OP)
i reviewed the PH diagram of the system and noticed that the discharge superheat is quite high.

My assumption: Since the discharge superheat is high it gives the compressor a hard time and it needs to exert extra power to reach the superheat temp. By needing extra power it triggered the high compressor lift.


what do you think about my assumption kiwimace?

RE: what does HIGH COMPRESSOR LIFT mean?

Compressor lift is simply the saturated condensing pressure minus the saturated evaporator temperature.

It's a mostly useless term, since almost no real systems operate at saturation on either side of the compressor.

Measure actual system pressures and superheat.  Look at the PH diagram.

Don't worry about meaningless jargon.

RE: what does HIGH COMPRESSOR LIFT mean?

Usually this works the other way around.

Because of a warmer outdoor air temp or condenser water temp, you get a high condensing temp, which requires more lift, which uses more compressor energy.

 

RE: what does HIGH COMPRESSOR LIFT mean?

Here is another explanation:

Lift (or head pressure) is the difference between condenser refrigerant pressure and evaporator refrigerant pressure. Using defined pressure-temperature relationships, lift can also be measured with the LCHWT and the leaving condenser-water temperature. Further, when the LCHWT and condenser-water flow are constant, the ECWT can be used as a metric for lift. Because most condenser water systems are designed for constant flow, ECWT is the most common metric for lift. In comfort-cooling applications, lower ECWT indicates lower lift, which lowers the compressor work . The relationship can be summarized as: lower ECWT = lower lift = lower compressor work = lower energy usage. In comfort-cooling applications, ambient weather conditions often allow facility owners to take advantage of ECWT as low as 50˚ (at AHRI conditions). The capability to use lower ECWT significantly improves chiller efficiency. In fact, greater chiller efficiency can be achieved by lowering lift than by lowering load. The efficiency improvements due to lower lift can be realized in both single-chiller and multiple-chiller installations.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources