Custom Building of the EV BATTERY FLUSHING RIG LITHIUM ION Rig.

EV BATTERY FLUSHING RIG LITHIUM ION

This equipment is used to flush, purge clean and verify the quality standard of the coolant used in a Lithium Ion battery pack typically found in an electric vehicle.

The battery packs are high energy items, very densely packed and during their operation heat is generated. 

The heat is regulated by allowing a non-conductive coolant fluid to pass through internal spaces and insulator galleries.  In this application the use of Alpha 2 fluid is employed.

It is actively circulated as a closed loop system through the battery pack and an external heat exchanger to control the temperature.

The insulation and spacing distance between the internal active parts of the battery must be maintained throughout its life span. 

Contaminated fluid as it is circulated may gather conductive particles and other impurity remains from the manufacture process of the cells and the casing.

The fluid flow may concentrate or build up the impurities to form electrical bridges that may compromise the minimum insulation space distance. 

This can result in a short circuit, cell failure and in extreme cases a catastrophic pack failure.

CRITICAL.  

Flushing Pressure not to exceed 1.5 Bar. 

Flushing fluid temperature not to exceed 60 Degrees Centigrade. In operation 44 - 48 degrees Centigrade as per customers requirements.

Flushing Circuit cleanliness – ISO4406:99 <13/01/9 calibrated to ISO11171:2020

Flushing process cannot proceed unit fluid reservoir circuits have been cleanliness verified by Pamas OLS50P particle counter and at the correct operating temperature. 

This process is interlocked by the PLC and system control.

The flushing rig contains 2 OLS50P units.

Operations and build.

The apparatus will be powered from a 240Vac 50Hz 32Amp source.

The core frame is of 304 Stainless box section 3mm. The tank from 316SS folded and welded plate 6mm.

The frame is fitted with a bund tray of 80 litres and a fluid leak optical sensor detector and mounted on casters. 

All parts in contact with the Alpha 2 fluid are 316 stainless and hard piped with schedule 10. The frame is Stainless welded, the flushing tank of 100 litres operated at 80 litres operation capacity is of Stainless 316, and all internal welds dressed and polished.

There are 3 filters. One for the cooling circuit and tank, the other two for the battery pack.

The tank will be a 3-micron TRAP Breather.

Battery pack filters are by Hy-Pro,  DFE media, Beta 4000 3 micron.

All are independently monitored via pressure differential sensors.   These indicate efficiency and end of life.

The reservoir tank has optical fluid view level gauges as well as an electronic capacitive level sensor that reports back to the PLC unit. 

There are two fluid circuits but share a common reservoir. A cooling circuit and a flushing circuit, both have independent motors and variable speed drive.

The cooling circuit has an in-line air blast heat exchanger.  The tank as 2x 1Kw heaters. 

A combination of heating and cooling will be used to keep the flushing temperature in operation 44 - 48 degrees Centigrade as per customers requirements.

The fluid flushing temperature is monitored by a sensor, and shadowed by a second. The tolerance between the two is a fraction of a degree.  If there is a deviation the unit will fail safe.

There is a 3rd master temperature sensor set to function at 55 deg C and 60 Deg C.

At a temperature of 55 degrees it will shut off the heating elements, over-ride commands and set the forced air cooler to maximum performance.

This will be recorded as a fault condition and require operator investigation.

If a temperature of 60 degrees C is reached it will cause a “scram” function via a master SIL2 relay to be Invoked.

This will shut off the heating elements, over-ride commands and cease operations as it will operate the emergency stop function. 

There is a pressure sensor and flow meter in the flushing circuit and this is fed to the speed control of the flushing motor to ensure a constant pressure and Reynolds (Re) fluid flow number for the battery pack under test.

There are 2 Pamas OLS50P units in operation, one to monitor the Reservoir tank and the other to monitor the battery pack.

Control

PLC is a Siemens S7-1200 with safety fail module.

Siemens PID temperature control linked to flow and maximum pressure sensors.

Human interface Siemens TF900 9” (HMI)

2 OLS50P Pamas particle counters with a yearly calibration traceable back to ISO11171:2000 Standards.

If required, all data can be remote monitored via standard Network TCP connections or additional Wi-Fi.

All sensors are monitored and report back to the PLC to indicate operational status and recording of data. This can be displayed to the operator and other interactive controls for process operation.

Operator Emergency STOP button causes the Rig to default to a safe mode.

LITHIUM ION EV BATTERY FLUSHING RIG