| Title | OPTIMIZING HYBRID NONCONDENSABLE GAS REMOVAL SYSTEMS FOR FLASH STEAM GEOTHERMAL POWER PLANTS |
|---|---|
| Authors | J.C. Richardson |
| Year | 2015 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Noncondensable gas, NCG Removal System, Steam Jet Air Ejector, Liquid Ring Vacuum Pump, Hybrid Vacuum System. |
| Abstract | The energy required to operate the Noncondensable Gas (NCG) Removal System for the condenser of a flash steam geothermal power plant constitutes a significant parasitic load affecting the overall power production and efficiency of the generating unit. Hybrid vacuum systems, incorporating steam jet air ejectors and liquid ring vacuum pumps, have proven to be reliable and efficient in this service. However, for optimum efficiency, the designer of the hybrid vacuum system must evaluate the thermal efficiency, the thermal limitations and the capitalized energy costs of the NCG Removal System design for each specific application as well as the installed cost and effect on associated systems design. Both environmental and commercial factors must be considered along with the properties of the geothermal resource in the optimization of NCG Removal System design. Environmental factors such as design basis ambient temperature and absolute barometric pressure physically limit the operating range of the liquid ring vacuum pump. Capitalized costs of geothermal steam, cooling water and electrical power requirements for the NCG Removal System must be considered in the division of the gas compression work between the steam jet air ejector stage and the vacuum pump stage. Steam usage of the NCG Removal System also directly affects cooling tower sizing and cooling water system design. This paper defines the required design basis parameters and illustrates how these parameters are used to optimize the NCG Removal System design for a typical flash steam geothermal power plant. |