Condensers geothermal

The Okuaizu geothermal system is characterized by high temperatures (maximum 340°C), high salinity (about 2 wt% total dissolved solids (TDS)) and large amounts of non-condensable gases (1 wt% CO2 and 200 ppm H2S). The pH of the hydrothermal solution measured at 25°C is 6.44 (Table 2.6). However, the pH of the original fluid in the reservoir is computed to be 4.05. This pH as well as alkali and alkali earth element concentrations are plotted near the equilibrium curve of albite, K-mica, anhydrite and calcite (Fig. 2.19) (Seki, 1991). 

Sometimes it may become necessary to shut-in a gas well when the demand for gas is low. In such instances, the well is shut-in for an indefinite period, after which it is reopened and production is resumed. It often has been found that the production rate of gas from the reopened well is substantially less than it was before the well was shut-in. During production, the inner wall of the production tubing will be coated with a film of condensed freshwater because of the geothermal gradient. This water flows down when production is interrupted and can cause formation damage. This may occur because clays are normally saturated with brine water and not with freshwater. This swelling can be prevented with the injection of some additive, for example, sodium chloride, potassium chloride, calcium chloride, or an alcohol or a similar organic material [1853]. 

Battistelli A., Calore C., et al. The simulator TOUGH2/EWASG for modeling geothermal reservoirs with brines and non-condensible gases. 1997 Geothermics 26(4) 437-464. 

The salt- and Cu2+-catalysed condensation of peptides provides a very simple polymerisation reaction with remarkable efficiency at 80°C. The proposed mechanism is shown in Figure 8.17 for the dimerisation of glycine. The presence of Cu2+ is important in this process and is unlikely to be present in the geothermal vent environment but it does require only small quantities of O2 to oxidise copper. A better condensation reaction would be autocatalytic and provide a template for future generations - in short, a genetic code. 

Micellaneous Volcanic Gas Condensate [2, 19] Micellaneous Geothermal Water [5, 6]... 

Figure 6. Stable-Cl isotopic composition of fumarolic minerals, volcanic gas condensates and geothermal waters. Bracketed numbers correspond to references listed in Figure 3, Figure 4, and, [18] Wahrenberger et al. 1997 [19] Godon et al. 2004 and [20] Kaufmann 1989.

At a geothermal energy source, dry steam at 700 kPa and 170°C is available at a mass flow rate of lOOkg/sec. A barometric condenser at lOkPa is used to decrease the turbine exhaust temperature. Find (a) the power produced by the geothermal power plant as shown in Fig. 2.22a. (b) What is the power produced without the barometric condenser ... 

Figure 2.22b Dry-steam geothermal power plant without condenser.

At a geothermal energy source, a mixture of 80% steam and 20% water at 140°C is available at a mass flow rate of Ikg/sec. A barometric condenser... 

The most adverse environmental effect of geothermal energy utilization is chemical pollution, from gaseous components in steam that are discharged into the atmosphere and from aqueous components in spent water that may mix with surface- and groundwaters. This problem has been reduced by injecting into drillholes both the separated water and the steam condensate. Injection is specifically discussed in a separate section below. 

Beall, J. J., Enedy, S. L. Box, W. T. Jr. 1989. Recovery of injected condensate as steam in the south Geysers field. Geothermal Resources Council Transactions, 13, 351-358. 

The simplest of the geothermal cycles is the direct-intake non-condensing type. Steam from the geothermal well is directly passed through a turbine and exhausted to the atmosphere without condensation. Such cycles require 15-20 kg steam per generated kWh. Condensing plants (with condensers at the turbine outlet) need only... 

The power-generating potential of a water-dominated resource depends on the geothermal fluid temperature and production flow rate (Fig. 2). The figure gives the net power output, which accounts for parasitic loads caused by the condenser and feed pump power requirements. The output power from two-phase water-steam or steam alone is much greater than the curves shown for liquid in Fig. 2. 

Fig. 2. Geothermal power generation capacity of a geothermal resource. Feed pump and condenser parasitic power have been accounted for. (Modified from Nichols 1986).

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