View Full Version : high discharge pressure after replacing the new condenser for 30 gh carrier chiller.
24-07-2013, 07:29 AM
Yet, I did not visit the site. I have been told on telephone. Chiller model:30gh100,carrier chiller. New condenser coil 15fpi/inner grooved tube was replaced. After commissioning discharge pressure is very high. Client (carrier) is not approved condenser replacement job .After more inspection, again replaced the plane tube condenser coil 18fpi/plain tube for circuit A only. Commissioned with 700micron vacuum and dupont suva refrigerant. Required gas charge as per catalogue 29kg for each circuit. But now not fully charged. Primary readings are below.SP=70/DP=340/LIQUID LINE PRESSURE=310/AIR ENTERING TEMP=40C/LIQUID LINE TEMP =49C/DISCHARGE LINE TEMP=96C.othor readings are not available. Tomorrow I will go to site and full reading update you. Have any comments…….
26-07-2013, 03:34 AM
CIRCUIT - A
CIRCUIT _ B
Saturated suction Temperature.
Suction line Temperature.
Super Heat-compressor(REQUIRED 16C)
Saturated cond. Temperature.
discharge line temp
Liquid Line Temperature.
Liquid line pressure
Pressure drop in high side
Condenser CFM as per catalogue
condenser avg.air veleocity
700FPM AND 529 FPM.
condenser coil face area
Condenser Air In Temperature.
Condenser Air Out Temperature.
Condenser Air delta Temperature.
Chilled Water In Temperature.
Chilled Water Out Temperature.
chilled water Delta T
Chilled Water in Pressure
Chilled Water Out Pressure
Chilled Water delta Pressure
Chilled water flow rate
Refrigerant Charge approximates
Refrigerant Charge as per catalogue
System Sight Glass
Slightly flashing at exv 100% open
Avg. Amps Comp A1-06E299-CARLYLE
Avg. Amps Comp A2-06E270-CARLYLE
Avg. Amps Comp B1-06E299-CARLYLE
Avg. Amps Comp B2-06E270-CARLYLE
1. Condenser TD is high-so the condenser is undersized.
2. Condenser air delta T is high-but calculated cfm is matching to the catalogue cfm.
3. Condenser approach is low=so the heat transfer takes place.
4. Sub cooling is very low,as per catalogue minimum need 7k.
5. Chilled water delta T is low, because only two compressors are working, B circuit is shut off.so to be maintained the delta T is 2.5c.
I am again thinking,have you any comments.
26-07-2013, 06:44 AM
anybody can say, how to design the lower td air condenser?what will be the specifications?can increase fin pitch or row?but it will affect the air way resistance and pressure drop in condenser.
29-09-2013, 11:15 AM
and a 30psi pressure drop
30-09-2013, 12:07 AM
Clarification : an 18fpi coil replaced by a 15fpi coil. If that is correct, coil is short of surface area. Which will directly effect discharge conditions. It will be more evident at high ambient temps.
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