Product purity

Purity is a key indicator of the quality of CSP thermal oil, and solar thermal power generation systems have high requirements for the purity of thermal oil. Low purity thermal oil is difficult to maintain a long service life.

The production process determines the purity of the thermal oil. Chen Hao stated that the purity of products produced by different production processes varies. Meanwhile, during the use of heat transfer oil, due to human error and other reasons, foreign objects may mix in, resulting in a decrease in the purity of the heat transfer oil. The impurities may cause the oil to deteriorate rapidly and become ineffective, shortening the service life of the heat transfer oil. More seriously, if unsafe chemicals are mixed in, they may react chemically with the heat transfer oil at high temperatures, posing unpredictable safety risks to the system. Therefore, whether from the perspective of service life or safety, the purity of CSP thermal oil must be as close to 100% as possible.

Service life

Both mineral and synthetic heat transfer oils have the commonality of organic matter, which is that they undergo thermal cracking and oxidation reactions at high temperatures. In the trough type solar thermal power generation system, the temperature of the heat transfer oil is maintained within the high temperature range of 293 ℃~398 ℃. After running for a period of time, different degrees of cracking will occur, that is, some of the heat transfer oil will be converted into low boiling, high boiling, and insoluble cracking products, causing a change in its quality. This phenomenon directly affects the service life of the heat transfer oil. Therefore, when the low boiling and high boiling fractions of the heat transfer oil precipitate after several years of use reach a certain ratio, it is necessary to carry out some exclusion treatment.