Refrigerator refers to the compressor used in compression refrigeration. Because of its different working conditions and compression medium, it is different from the general air compressor.
According to the working characteristics of the refrigerator and the specific requirements of lubricating oil and the deployment of lubricating oil type, commonly used refrigerants are: Freon, ammonia, lithium bromide, methane chloride and so on.
Pour point refers to the lowest temperature at which the cooled sample can flow under the specified test conditions.
Condensation point refers to the highest temperature when the oil surface of the sample is no longer moving under the specified test conditions, which is expressed in ℃.
The physical meaning of pour point is one of the parameters reflecting the fluidity of oil at low temperature. The lower the pour point is, the better the fluidity at low temperature is.
The pour point of the same oil is a few degrees higher than the freezing point. The freezing point is commonly used in the past, and the pour point is universally used in the world.
Pour point or high freezing point, the low temperature fluidity of the oil is poor.
According to the pour point of oil, people can consider the measures that should be taken when transporting, storing, sending and receiving under low temperature condition, and can also be used to evaluate the low temperature performance of some oil.
Testing standard: GB/T3535-2006, the standard and ISO 3016-1994 equivalent
Standard for refrigerating oil: GB/T16630
Instruments for the experiment
1.SH113C automatic pour point tester, developed and produced by Shandong Shengtai Instrument Co., Ltd.
2. Pour point test tube conforming to GB/T3535.
First, preparation work
1. After the instrument is unpacked, please count the accessories according to the packing list. If there is any damage, please contact our company.
2. The instrument should be carried vertically, and the tilt Angle along the height of the instrument should not exceed 30 degrees. It should be placed in a dark place and placed smoothly, otherwise there will be vibration after the start of the instrument, which will affect the service life of the instrument.
3, the instrument power supply is connected to the capacity of more than 220V/10A socket, pay attention to must have a good grounding wire.
Second, the experimental process
1. Pour point measurement: put the rubber stopper with sensor and detector on the test tube, and put the test tube into a cold bath.
2. Click the pour point measurement to enter the pour point measurement interface.
3. The four buttons on the main interface for pour point measurement are the main interface, parameter setting, system setting and historical data respectively.
The main display area is the trend chart of sample temperature change with time, which can show the temperature value of sample and metal bath. The right display area will show the specific value, and the lower part is the expected pour point and test tube experimental results.
In the lower right corner are the start button, tilt button, and close button.
4. After all the preparation work is done, click the "Start" button to carry out the test. During the test, the system will automatically detect the pour point.