HP / IP Turbine Efficiency Test

Typical Control Room Data Sheet

HP / TP Turbine Efficiency Test

Typical DAS Points for HP / IP Turbine Efficiency Testing

CONTENTS

1.0Introduction

2.0Objective and Scope

3.0Evaluation Criteria and Associated References

4.0Plant Specific Data and Characteristics

5.0Test Instrumentation

6.0Instrument Installation

7.0Test Instructions

8.0Test Frequency

9.0Personnel Needed

10.0Test Set Up

11.0Duration of Test Run and Frequency of Readings

12.0Computation of Rest Results

13.0Analysis

14.0Report

1.0Introduction

After steam has transferred its useful heat to the turbine, it passes onto the condenser. The work obtained by the turbine from the steam will increase as the back pressure is reduced, so it is always desirable to keep the back pressure at minimum achievable level. In fact, condenser back pressure is the most important operating parameter of a unit, therefore, the factors which worsen back pressure must be clearly identified so that effective remedial measures can be taken once they are detected.

There are various controllable parameters to improve/maintain the condenser performance, such as cleanliness, air-ingress, C.W. flow, etc.

In view of this, it is recommended to carry out simplified routine performance test on the condenser at certain frequency to identify the level of deviations and performance trend. The intent of this document is to layout a standard test procedure for adoption at all units/plants.

2.0Objective and Scope

The scope is limited to the condenser. This test procedure shall determine the condenser performance with regard to one or more performance indices as follows.

2.1Absolute Back Pressure Deviation from Expected Valve.

2.2Terminal Temperature Difference (TTD).

2.3Cleanliness Factor.

2.4Sub-cooling of Air-steam Mixture and Condensate.

2.5Heat Transfer Coefficient.

2.6Effectiveness of Cleaning the Tubes.

2.7Effects of Physical Changes in the Condenser like New Tubes, etc.

2.8Circulating Water Velocity in Tubes.

2.9Circulating Water Temperature Rise.

2.10Flow of Air-steam Mixture.

2.11Dissolved Oxygen in Condensate.

2.12Effect on Heat Rate and its Financial Implications

3.0Evaluation Criteria and Associated References

3.1Evaluation Criteria

Mainly based on ASME Performance Test Code - 12.2, 1996 on Steam Condensing Apparatus and HEI Standard for Steam Surface Condensers.

3.2Associated References

ASME Performance Test Code 19.1 - 1985, Measurement Uncertainty ASME Performance Test Code 19.2-1987, Pressure Measurement ASME Performance Test Code 19.3-1974, Temperature Measurement.

4.0Plant Specific Data and Characteristics

4.1Condenser Design Data as per Annexure - I.

4.2Heat Load Vs. Condenser Back Pressure for Different C.W Inlet temperatures

4.3C. W. Pump Characteristic Curve

4.4Generator Loss Curve

4.5VWO Heat Balance

5.0Test Instrumentation

The parameters required to be monitored to conduct the condenser performance test consists of temperature, absolute/differential pressure, and C. W. flow. The number of instruments required depend on the size and configuration of the unit to be tested.