ISO INTERNATIONAL STANDARD 18888 First edition 2017-10 Gas turbine combined cycle power plants Thermal performance tests Turbines a gaz - Centrales a cycle combiné - Essais de performance thermique Reference number IS0 18888:2017(E) ISO IS02017 IS0 18888:2017(E) Contents Page Foreword Introduction. . vi 1 Scope 2 Normative references 3 Terms and definitions . Symbols and units .. 6 5 Test boundary, 6 Preparation for test. 11 6.1 11 6.2 Performance degradation. .12 6.3 Measurement classification 12 6.4 Design and construction phase recommendations 12 6.5 Test procedure, 13 6.6 Field preparations for the performance test. 14 6.7 Instruments and measuring methods . 16 6.7.1 General.a. 16 6.7.2 Electrical power measurement. .16 6.7.3 Flow measurements x 17 6.7.4 Temperature measurements 18 6.7.5 Relative humidity measurements 22 6.7.6 Pressure measurements 23 6.7.7 Data acquisition system.. 25 6.7.8 Wind velocity 25 6.7.9 Storage vessel levels 25 6.7.10 Data sampling. 26 6.8 Determination of fuel properties. 26 6.8.1 General.. 26 6.8.2 Tests on fuel gas. .27 6.8.3 Tests on liquid fuel. 27 6.9 Determination of cooling water flow into the condenser .28 6.9.1 General. 28 6.9.2 Energy balance method 28 6.9.3 Cooling water pump performance curves. 31 6.9.4 Direct flow measurement. 32 6.10 Measurement uncertainties .. 32 6.11 Maximum allowable uncertainties . 34 6.12 Calibrationa 35 Execution of test. .36 7.1 Base reference conditions .... 7.1.1 General.. .36 7.1.2 Specified gaseous fuel, .37 7.1.3 Specified liquid fuel.. 37 7.2 Preliminary test.. 38 7.3 Performance test .38 7.4 Duration oftest runs. 7.5 Auxiliary equipment operation. .39 7.6 Tests with inlet air heating system. 39 7.7 Tests with inlet air cooling system.. 7.8 Maximum permissible variation in operation conditions 40 8 Calculation of results for absolute test. 41 8.1 41 @ IS0 2017 - All rights reserved ii IS0 18888:2017(E) 8.2 Correction to base reference conditions. 41 8.2.1 General... 8.2.2 Correction curves based correction approach 42 8.2.3 Thermodynamic heat balance model based correction approach 43 8.2.4 Boundary parameters for correction .. 8.2.5 Description of corrections tobasereference conditions 46 8.3 Power output for combined cycle overall test . .50 8.3.1 Measuredpoweroutput.. 50 8.3.2 Power output corrected to nominal power factor. 52 8.3.3 Corrected power output... 52 8.4 Heat rate for combined cycle overall test 53 8.4.1 Measured heat rate/measured thermal efficiency 53 8.4.2 Corrected heat rate / corrected thermal efficiency... ..53 8.5 Power output of steam turbine determination for combined cycle in single shaft configuration 54 9 Part load tests .54 9.1 General. 54 9.2 Test set up and conduct 55 9.3 Correction method for part loads . 57 10 Calculation of results for comparative test. .57 10.1 General 57 10.2 Comparative performance test uncertainty. .57 10.3 Preparation for comparative test.. 58 10.3.1 Instrumentation, .58 10.3.2Preliminary activities and plant settings 58 10.4 Execution of comparative tests and calculation of results 59 11 Test reportet.n 11.1 Form of the report. 59 11.2 Detailed report.. Annex A (informative) Typical secondary variables, 61 Annex B (informative) Numerical examples of uncertainty calculation .. .64 Annex (informative) Procedure for power factor conversion .69 Bibliography 73 iv @ IS0 2017 - All rights reserved IS0 18888:2017(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (Iso member bodies). The work of preparing International Standards is normally carried out through Iso technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. ISo collaborates closely with the International Electrotechnical Commission (IEC) on all m