I have made single stage cooler for PC. I have problems wih cap
tube


System Components:
Tecumseh cdj2464z lbp hermetic compresor,50 Hz 1,5 HP
5,8kBTU
580 Wats Cooling at -40C Te,40C Tc

0,75 kW condenser 5m2 ,220V,50 Hz 75 W fan
0,031" 2,2 m cap tube
Castell Drier
Special evap for CPU
Vapour / gas separator 2lt at suction
Cap tube is at the round of suction pipe 12mm ID
Ref: 404a
Pressure gauges at exit point of drier and suction port
K Type Temp. Sensor at the top of the evap
250 W Heat load cell at the bottom of evaparator


Results 250 Watts Heat Load Off
Static charge :7 bars
Operation pressure:13 bars at high side , deep vacuum at suction
Idle Temp at the top of evap -55C/-56C (From ambient temp 25C to -56C It takes 2 minutes)

When System is 13 bars,-55C at top of evap I give current to heat load cell

The temperature at top starts to drop down, High side pressure rises 14 bars, Suction pressure is still deep vacuume
Within 100 secs temp at top of evap reaches -18C and If I dont cut energy of cell evap reaches +C's.

I have used rotary compressors before this cooling with 1 HP 12000BTU rotary compressors I can handle 350W's at lower than -40C with %90 r404A+ %10 R410a. Cap tube was same 2,1m-2,2m 0,031".
Since rotary compressors are too loud I wanted to use Hermetic one.


Hermetic Compressor is weak in terms of BTU but According to Tecumseh documents Thic compressor have to hanle 400W Pe at -40C's

I have checked Tecumseh's cap sizin program and Danfoss Cap sizing program. They gives me 1,9 m 0,042" cap tubes.

My rotary' are ok with 0.031" 2 meters but this hermetic systems fail?


I have already check oil, re vacuum system, change drier. Result is same


How will I modify system If you help me I will be very glad.


Adding more gas: I think I can add little amount of R404A or R410A Static cahrge to 7,5 bars

Changing cap tube to which size?

Thx Memet Can from Istanbul/Turkey