Coolers flow through turbine

We can then add the two cycles together as shown in Fig. 8.4c, to form a semi-closed plant. There is double the flow through this new plant, double the heat supply and double the work output. Strictly, the total heat rejected is not doubled half the turbine exhaust is now discharged to the atmosphere and half the heat rejected into a cooler before it is recirculated into the compressor. The thermal efficiency of this double semi-closed plant is unchanged from that of the original closed cycle and the original open cycle. So there is apparently no thermodynamic advantage in semi-closure it is undertaken for a different purpose. 

Where hot ambient temperatures are expected, overall turbine efficiency and horsepower output can be increased by installing an evaporative cooler in the inlet. Inlet air flows through a spray of cold water. The temperature of the water and the cooling effect caused by the inlet air evaporating some of the water cools the inlet air. In desert areas where the inlet air is dry and thus able to evaporate more water before becoming saturated with water vapor, this process is particularly effective at increasing turbine efficiency. 

A cogeneration cycle as shown in Fig. 5.19 is to be designed according to the following specifications boiler temperature = 500° C, boiler pressure = 7 MPa, condenser pressure = 5 kPa, process steam (cooler 2) pressure = 500 kPa, mass rate flow through the boiler = 15 kg/sec, and mass rate flow through the turbine = 14 kg/sec. 

The Joule-Brayton (JB) constant pressure closed cycle is the basis of the cyclic gas turbine power plant, with steady flow of air (or gas) through a compressor, heater, turbine, cooler within a closed circuit (Fig. 1.4). The turbine drives the compressor and a generator delivering the electrical power, heat is supplied at a constant pressure and is also rejected at constant pressure. The temperature-entropy diagram for this cycle is also... 

In the interest of energy conversion, process heat can be obtained from a heat recovery unit in which heat is recovered from turbine or reciprocating engine exhaust. In a heat recovery unit, an exhaust gas flows over finned tubes carrying the fluid to be heated. The hot exhaust gas (9()0"F to I.2(K) F) heats the fluid in the tubes in a manner similar to that in which air cools the fluid in an aerial cooler. It is also possible to recover heat from exhausts by routing the exhaust duct directly through a fluid bath. The latter option is relatively inefficient but easy to install and control. 

After leaving the turbine, the helium then passes consecutively through the hot side of the recuperator, then the pre-cooler, the low pressure compressor, intercooler, high pressure compressor and on to the low temperature side of the recuperator before re-entering the reactor vessel at 488°C. Figures XIV-1 and XIV-2 provide a schematic representation of the PBMR flow path and conceptual primary system, respectively. 

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