Oil Pump Test
The oil pump is very important because is circulated the oil in the oil loop to move the heat from the receiver pipe to the heat exchanger. If the oil pump is not functioning and the sun is strong the oil in the receiver pipe can boil and catch fire. The oil pump is controlled by the Oil Pump Control system for normal operation and to prevent oil in the receiver pipe from over heating.
The oil pump must withstand high heat oil, pump at a sufficient rate and be electrically driven (see oil pump).
Please see the Oil Pump Test Videos below.
Hot Oil pump test video 39
Pump test speed control test video 38
Oil Pump Running test video 37
Oil Pump flow test video 36
Oil Pump build test video 35
Oil Pump design test video 33
For this test we built an oil pump using a used car ford engine oil pump (part number C20E-6604-A) and a car radiator fan motor I found in the garbage. I made a wood frame with 1x6 boards and connected the motor and pump using gears and a socket extension bar. All these materials were found in the garbage for free. I also had to add my own homemade flanges I made out of electrical box fittings. I used 2 cut threaded rods and nuts on each flange. I added 2 thin cork gaskets to each side. I could then screw a copper pipe fitting and soldered up some 1/2 inch copper pipe for the hot oil test.
First a flow test was conducted. While the pump was circulated oil in a pot another container was slid under the pump exit. The pump was timed and after about 3 seconds 1 liter had been pumped. This works out to about 15 litres/minute which is what is required for the 24 foot long solar thermal car oil loop. This pump could replace all the oil in the receiver pipe in a minute.
A resistive speed control was made to help controlled the pump speed for testing. At full power the pump was running very fast and splashing oil everywhere. This control has 5 different speeds that each have different resistances.
With the speed control we were now ready to conduct a hot oil test. All that was required was to put the oil pot on the stove and circulate this hot oil. A thermocouple was used to measure the pot oil temperature. Another thermocouple was used in the oil exit pipe. This test was used to ensure the copper pipe and oil pump could withstand the high temperature and also test the pipe thermocouple hot oil measuring.
The pot was slowly heated to 155C and the pump was turned on and off to see the pipe thermocouple reaction time. The pump leaked more oil from the drive shaft at high temperatures. Other then that the test went great. It pumped much fasted with hot less viscous oil. Please see the graph below. The Y axis is the temperature in Celsius and the X axis is time in seconds.