Combining with the performance test standards for air cooling system

the universal formula of the uncertainty calculation for thermal performance guarantee value by general characteristic curve method was derived.By this formula

the performance tests uncertainty for a mixed indirect air cooling system was determined as 0.032 5.It can be seen from the uncertainty distribution that

such factors as water temperature at inlet/outlet of the tower

circulating cooling water flow and pressure in condenser were main parameters affecting the tests uncertainty.The uncertainty was evaluated from several aspects

like measuring point number

instrument accuracy

parameter fluctuation range and so on.It indicated that the water temperature at inlet/outlet of the tower should be measured at multiple points;the uncertainty of the test results can be reduced by about 0.005 3by enhancing the accuracy of flow measurement instrument for circulating water of 1%;selecting appropriate test time and controlling the measuring parameters fluctuation be within a reasonable range can effectively reduce the uncertainty of the test results.