A conference was held on April 3, 2019, in Dhahran, Saudi Arabia to focus on issues associated with older installed combined cycle power plants. Adel Al-Shuraim, CEO Tamimi Energy, sponsored this conference. This one-day conference was attended by over 80 customer personnel, and 6 vendors, and consisted of the following presentations:
1) Introductions by Adel Al-Shuraim
2) Combined Cycle Plant efficiency improvement studies—Joel Holt and Bruce Martindale, CoreTech
3) Combined Cycle Plant Quicker start up cycle times-- Joel Holt and Bruce Martindale, CoreTech
4) Gas Turbine Non-Capital Parts uprates—Bob Johnston, KGI
5) HRSG improvements—Habib Grini and Raphael Stevens of CMI
6) Steam Turbine upgrades—Dave Hagenbuch, MD&A
7) Training programs for Gas Turbine, Steam Turbine and Generator—Dave Hagenbuch, MD&A
8) Exhaust system upgrades/repairs, including dampers—Moustafa Al-Shami, Braden.
This conference was attended by owners and operators of all the combined cycle power plants in Saudi Arabia—15 combined cycle plants in total.
The focus of each presentation was to address specific issues that each vendor had experience with for other combined cycle power plants, and to show how this experience can also be applied to the combined cycle plants in Saudi Arabia. The overall theme is that the collection of vendors at the conference had agreed to work together to provide complete solutions for the customers who have combined cycle power plants.
The combined cycle power plants in Saudi Arabia have the same issues as combined cycle plants in other areas. The OEM’s (and third parties)for the major plant components are willing to help with issues associated with their own equipment, but no one comes prepared to provide integrated solutions for the entire combined cycle plant.
Some of the programs presented included;
Quick start up—90 minutes—for a warm re-start of a CC Power Plant. The significant penetration of renewables into the power generation market has resulted in many CC power plants having cycling duty, which includes quick start up when the renewal energy source is suddenly not available. Most new unit CC plants for the past few years have this requirement as part of the new unit installation. But, for CC plants over 5 years old, frequently warm starts take over 4 hours. By providing applicable procedures, software, and instructions, a 90-minute warm start is possible for all older CC plants
Efficiency improvements—all older CC plants have suffered reductions in CC efficiency—many of which can be addressed. To fully assess areas that can be addressed to improve efficiency, a full new heat balance needs to be done, and compared with the original heat balance to show the main areas that need to be addressed.
Gas turbine uprates---focused uprates within the capability of the existing equipment can be easily implemented. Most older gas turbines get upgraded parts when they purchase spare parts, as all OEM’s continually improve the capability of the parts. But, the OEM’s usually do not assess the overall capability of the gas turbine, when only selling spare parts. Frequently a thorough review will result in an additional 3% power from the gas turbine, as well as an increase in exhaust energy. Thus, the total CC plant will get additional power, and improved efficiency.
Audits of all operating procedures for combined cycle plants—frequently significant improvements in operations have been developed with more recent CC power plants. But, the overall integration contractor who originally installed the plant, does not continue to provide assistance to the CC plant customer personnel.
Repairs and/or replacement of key exhaust system components: ducting, dampers, etc.
Upgrades for the steam turbines.
Training programs for Gas Turbines, Steam Turbines, and Generators
HRSG improvements – Over the years, the HRSG can loose on efficiency. Main reasons are typically related to flue gas by-pass around the heat exchangers, closing and baffling plates removed, fouling of the external heating surfaces due to deposits of soot and sulfur, and internal fouling due to improper water quality. Another aspects closely monitored is the good operation of the diverter damper and sealing tightness in Combined cycle operation.
For any CC plant customer to fully evaluate the impact of implanting any improvements to his CC plant, he needs a good economic analysis of the benefits. As most CC customers do not have the ability to do their own heat balances, or to assess the overall impact of making any specific change to any of the combined cycle equipment, it is difficult to get their management approval of any significant improvements. Thus, the CC plant efficiency continues to decline. The operator is not always immediately aware of the loss of efficiency, apart from the power output reduction. OEM’s have recommended some key parameters to be followed up, such as the flue gas temperature at the outlet stack, GT gas pressure increase, etc. The collection of vendors at this conference have formed an alliance to work together to provide a complete market basket of solutions, within the capability of the existing plant equipment, along with associated heat balances to show the benefit to CC customers.
Bob Johnston, President, Keck Group International coordinated this conference.
Please contact any of the following for any follow up discussions, or questions:
---Bob Johnston, President, KGI, 404-513-9318, bobjohnston99@comcast.net
---Joel Holt, Manager, Combined Cycle Engineering, 518-322-2970, jholt@cticus.com
---Haitham Al-Akkawi, manager, Tamimi Power. +966 56 001 1666, hakkawi@al-tamimi.com