Fluid ageing test rig

 

The fluid ageing test rig is used to compare different fluids using a real hydraulic network. It can be operated over longer periods of time and shows the ageing behavior of the fluids.

 

Operating principle

Layout Copyright: © ifas

The test rig represents two separate hydraulic circuits that apply different loads to the fluids. Due to the symmetrical design, a reference sample with mineral oil can be carried out for all tests.

 

Test bench setup

Fluid Ageing Test Rig Overview Copyright: © ifas

The test stand consists of two identically constructed hydraulic circuits. Figure 1 shows the setup. The drive is provided by an asynchronous motor (2) with a power of 30 kW, the speed is 1500 min-1. Up to 200 Nm can be delivered. Hydraulic pumps (3) in tandem design can be connected to the electric motor.

There are two independent fluid tanks (1) with a capacity of 50 liters. In addition, two centrifugal pumps (4) as filling pumps ensure low-cavitation suction of the main units. On the right side (5, 8) the load circuits are visible. They consist of a high-pressure filter with monitoring (5, 14), flow rate sensor (12, 13), pressure relief valve (11), adjustable bypass orifice (8) and cooler (10). Both circuits are also identical in design. The maximum operating pressure is designed for 300 bar.

 

Experimental procedure and results

Fluid Ageing Test Rig Overview Copyright: © ifas

The test rig is designed in such a way that novel fluids are always compared with a reference. The identical drive motor ensures that both hydraulic circuits experience the same load. By plotting hydraulic data such as pressure, flow rate and temperature over time, changes in the fluid can be shown. Furthermore, fluid sensors can be placed in the circuit to measure, for example, water content or electrical conductivity. Samples can be taken at regular intervals to measure viscosity.