Customer
Our client is one of the world's leading suppliers of heating and cooling systems. They contacted us to build a test bench for their range of domestic hot water tanks.
Tested product
Domestic hot water tanks:
A hot water tank, or cumulus, allows you to increase the temperature of the water to distribute domestic hot water in your house or flat.
Objective
To design a hydraulic test bench for testing hot water tanks in cyclic and static pressure tests.
The cyclic pressure test is carried out in accordance with EN 12897.
Problematic issues
As the hot water tanks under test have very large volumes (up to 1000 litres) and some of the tests have to be carried out at regulated temperatures (up to 90°C), the bench had to be able to generate both test pressures and a sufficient flow rate to ensure that the test temperature was homogeneous.
Solution and result
The test bench is a pressure generator placed next to the products to be tested. The hydraulic bench can test up to 4 hot water tanks simultaneously.
The products are connected to the bench via a connection board. The programmable cycle carries out the purging of the products. All connected products are subjected to the same test: identical pressure, flow and temperature.
A centrifugal pump can generate a static pressure of up to 20 bar and can deliver 50 l/min at 12 bar.
Pressure test:
The hot water tanks are subjected to a static pressure of up to 20 bar. The tests are carried out without water circulation. In order to prevent the water from heating up at the pump, an automatically controlled valve isolates the pump from the hot water cylinder and the pump can be switched off.
If the test pressure drops, the pump injects water back into the tank.
Cycling pressure test:
In contrast to test pressure testing, pressure cycling tests can be carried out at temperature. It is therefore necessary to have a flow rate during the test to ensure a good test temperature.
A manual control valve is used to adjust the pressure drop in the system, the pump cycles through the pressure according to programmable profiles.
