[Kimura]
In the morning of 12/12, the compressor operating conditions of two duct shield cryo-cooler units (Xfa and Xfs) in the central machine room were confirmed.
Step 1:
First, the temperatures of the cooling water inlet and outlet of the 12 compressors in the central machine room, including those that were stopped, were measured. The area measured with a contact thermometer was the area circled with magic marker in the attached photo 1 and 2.
The results are as follows;
| Cryo-cooler | Inlet Temp. (°C) | Outlet Temp. (°C) | Status |
| Xfa | 18.8 | 25.6 | Running |
| Xfs | 18.8 | 26.7 | Running |
| X-P-53 | 18.9 | 25.3 | Running |
| X-P-54 | 18.9 | 19.0 | Stop |
| X-P-55 | 19.0 | 25.5 | Running |
| X-P-56 | 18.8 | 18.9 | Stop |
| Yfa | 19.1 | 27.5 | Running |
| Yfs | 19.1 | 27.8 | Running |
| Y-P-53 | 19.1 | 27.9 | Running |
| Y-P-54 | 19.1 | 19.1 | Stop |
| Y-P-55 | 19.1 | 28.6 | Running |
| Y-P-56 | 19.2 | 19.1 | Stop |
The temperature of the water supplied to the compressor, alarm settings, and specifications are as follows;
The condition of the water supplied to the compressor:
Water supply temperarure:17.7 °C
Compressor cooling water alarm setting:
Cooling water inlet temperature abnormal > 35 °C
Cooling water flow (outlet temperature) abnormal > 46 °C
Compressor cooling water temperature specification: 5~25 °C
I confirmed cooling water temperature were within the specified value.
Step 2;
Next, I opened the compressor housing and measured the temperature of various parts inside the Xfs and Xfa compressor.
The measuring device was the same contact thermometer as in step 1, and the measurement points were as follows,
Helium gas supply (upper side of Photo 3)
Helium gas rerturn (lower side of photo 3)
(3) Adzobar IN (Photo 4)
(4) Adzobar OUT (Photo 4)
(5) Oil separator IN (Photo 5)<- (Equivalent to the temperature at the heat exchanger outlet)
(6) Oil separator OUT (Photo 5)
(7) Heat exchanger IN-1 (Photo 6) <- (Estimated to correspond to compressor outlet temperature)
(8) Heat exchanger IN-2 (Photo 6) <- (Estimated to correspond to compressor outlet temperature)
(9) Surface temperature of the main unit (LCD temperature sticker) (Photo 7)
The results were as follows;
| Xfs (°C) | Xfa (°C) | |
| Helium gas supply | 22.8 | 21.4 |
| Helium gas rerturn | 24.1 | 21.5 |
| Adsober OUT | 24.8 | 25.2 |
| Adsober IN | 24.0 | 24.5 |
| Oil separator IN | 21.4 | 20.0 |
| Oil separator OUT | 21.6 | 20.8 |
| Heat exchanger IN-1 | 89.0 | 62.3 |
| Heat exchanger IN-2 | 81.7 | 62.1 |
| Surface temperature of the main unit | 55 | 50 |
From this measurement, it was confirmed that the compressor outlet temperature of Xfs was approximately 20°C higher than that of Xfa.
However, the difference in heat exchanger outlet temperature is 1.4°C.
I am planning to contact SHI with the above data to see if the difference in compressor operating temperatures is within specifications.
