Virgo Logbook

AdV-INF (Environmental noise mitigation)

pierini, fiori, tringali, paoletti, soldani - 17:30 Wednesday 16 June 2021 (52167)

Slow-down and switch test on WEB hot water pumps

On Wednesday 16/06/21 we started slow-down tests on the hot water pump of WEB. We have proceded at steps of -5Hz starting from the standard 50Hz supply and switching between the left and right pump in order to check for different responses.

Before the test the following 4 accelerometers have been added:

CHANNEL NAME	ACC TYPE	LOCATION
ENV_WEB_HOTPUMP_OVER	PCB 393B12	Attached to the hot pump, at its base platform
ENV_WEB_COLDPUMP_OVER	PCB 356B18	Attached to the cold pump, at its base platform
ENV_WEB_HOTPUMP_FLOOR	Meggit 731-207	Fixed to the ground, between hot and cold pumps, slightly nearest to the hot
ENV_WEB_HOTPUMP_PIPE_IN	PCB 393B12	Attached to an exposed part of the pipeline that goes from the UTA to the boiler

Before the beginning of operations the right water pump was active, with 50Hz supply

12:28 UTC	we entered the WEB water pumps room
12:32 UTC	switch from right to left pump, at 50Hz
12:42 UTC	switch from left to right pump, at 45Hz
12:51 UTC	switch from right to left pump, at 45Hz
13:00 UTC	switch from left to right pump, at 40Hz
13:06 UTC	the security system shut down the boiler (low pressure)
13:08 UTC	the same right pump (no switch) is slowed at 35Hz
15:15 UTC	the supply of the right pump is increased from 35Hz at +1Hz steps: at 47Hz the boiler turns on
15:17 UTC	the supply of the right pump is decreased from 47Hz at -1Hz steps: at 40Hz the boiler turns off
15:18 UTC	the system is restored at the starting conditions (right pump at 50Hz); we leave the room.

During the whole process a regular series of glitches from air compressors occurred, every 3 minutes.

Comments to this report:

Paoletti - 8:40 Friday 18 June 2021 (52187)

There is a typo in the table showing the timing of the whole operation. All was done from 12:28 UTC to 13:18 UTC, so the table should be

12:28 UTC	we entered the WEB water pumps room
12:32 UTC	switch from right to left pump, at 50Hz
12:42 UTC	switch from left to right pump, at 45Hz
12:51 UTC	switch from right to left pump, at 45Hz
13:00 UTC	switch from left to right pump, at 40Hz
13:06 UTC	the security system shut down the boiler (low pressure)
13:08 UTC	the same right pump (no switch) is slowed at 35Hz
13:15 UTC	the supply of the right pump is increased from 35Hz at +1Hz steps: at 47Hz the boiler turns on
13:17 UTC	the supply of the right pump is decreased from 47Hz at -1Hz steps: at 40Hz the boiler turns off
13:18 UTC	the system is restored at the starting conditions (right pump at 50Hz); we leave the room.

Moreover there are two other sensors that should be taken into account for analysis: INF_WEB_HEATER_PRES_IN and INF_WEB_HEATER_PRES_OUT: they are temporarily acquired at 10kHz

Images attached to this comment

pierini - 11:12 Friday 18 June 2021 (52190)

Images displaying the location of the 4 added accelerometers with respect to the water pumps.

The red pumps on the left are the cold water pumps, whereas the black on the right are the hot water pumps.

The referring to left and right hot pump in the report is intended with respect to this sight, with the door on the back.

Images attached to this comment

pierini - 11:53 Friday 18 June 2021 (52193)

On Thursday 17/06/2021 we performed a long-term slow-down of the WEB hot water pump, in order to look for effects on the air conditioning system and the boiler.

The slow-down regarded only the right pump, which is the one usually active in this period. Here the timeline:

08:49 UTC: The right water pump supply is switched from 50Hz to 45Hz.

16:19 UTC: The right water pump supply is switched back from 45Hz to 50 Hz.

In attachment there are the shots to the inverter after each operation and the spectrogram of the 3 nearest accelerometers which see the hot pump line.

The main spectal line due to the hot water pump passes from 46.7Hz to 42.1Hz, according to the decrease on the velocity of the engine, which passes from 2891 rpm to 2599 rpm.

Images attached to this comment

pierini - 17:33 Wednesday 30 June 2021 (52376)

Here there is a presentation of the main analysis results of the slow down test.

There is the clear evidence that the main vibration lines associated to the pumps enter into the WEB platform, since most of them are recovered by the Guralp seismometer ENV_WEB_SEIS_N/V and many of the Newtonian sensors recently installed. We can find them, even very weak, on the WE: ENV_WE_ALS_ACC_Z sees these lines with a very little amplitude, too low to be significant.

There is an open point on the presence of a noise bump which covers a large frequency region around 35Hz: this noise seems to be correlated with the hot water pump behaviour in some indirect way.

More tests have to be done to clarify its origin.

Non-image files attached to this comment

Slowdown_tests.pdf

Tringali, Fiori, Paoletti, Passaquieti, Soldani - 15:38 Friday 02 July 2021 (52402)

This morning, we repeted the slow-down test of hot water pump at West End building. With respect to previous test, we performed the same test on cold water pump switching off the air conditioning system, as well.
Below, we report the single actions:

10:39 UTC --> AHU ON, cold pump OFF, hot pump ON @50Hz --> chillers stopped
10:50 UTC --> AHU ON, cold pump OFF, hot pump ON @45Hz
10:57 UTC --> AHU ON, cold pump OFF, hot pump ON @43Hz
11:03 UTC --> AHU ON, cold pump OFF, hot pump ON @40Hz
11:08 UTC --> AHU OFF, cold pump OFF, hot pump ON @40Hz
11:14 UTC --> AHU OFF, cold pump OFF, hot pump OFF
11:21 UTC --> AHU OFF, cold  pump ON @50Hz, hot pump OFF --> chillers restarted
11:27 UTC --> AHU OFF, cold pump OFF, hot pump ON @40Hz --> chillers stopped
11:34 UTC --> AHU OFF, cold pump OFF, hot pump ON @45Hz
11:40 UTC --> AHU pump OFF, cold  pump OFF, hot pump ON @50Hz
11:46 UTC --> AHU pump OFF, cold  pump ON @50Hz, hot pump ON @50Hz --> chillers restarted
11:50 UTC --> AHU pump ON, cold  pump ON @50Hz, hot pump ON @50Hz

End test

Ps The heater restarted when the inverter of hot water pump went over 47.3 Hz.

We installed the following sensors:

ENV_WEB_HOTPUMP_OVER
ENV_WEB_COLDPUMP_OVER
ENV_WEB_HOTPUMP_PIPE_IN
ENV_WEB_UTA_CR_PIPE_ACC (inside experimental hall)

The INF channels

INF_WEB_HEATER_PRES_IN
INF_WEB_HEATER_PRES_OUT

are still in operation, acquired at 10 kHz