370
11 Power Gas Turbines
used to drive vehicles, ships, propeller aircraft and helicopters. Gas turbine driven
vehicles are large power vehicles, as off-highway trucks, excavators, tanks and
train locomotives. Also ships requiring high propulsive power in limited available
space are gas turbine driven. This applies mainly to fast container ships, fast ferries, coast guard patrol boats and military ships like frigates and torpedo ships. Gas
turbines are also applied for aircraft propulsion. These are commonly called aero
gas turbines. Gas turbines for larger aircraft do not feature an outgoing shaft. The
turbine part drives a compressor part and a part for thrust generation by acceleration
of air, termed fan. The combustion gas leaving the turbine part is applied to generate
thrust as well. Aero gas turbines are discussed in Chap. 12. The term aero gas turbine is commonly applied to all turbines for aircraft propulsion, including outgoing
shaft machines for driving the propeller of a propeller aircraft or a helicopter rotor.
Figure 11.1 represents a closed cycle gas turbine. The gas delivered by the compressor is heated by two heat exchangers. Heat exchanger 1 extracts heat from the
exhaust gas of the turbine. Heat from an external source is added in heat exchanger
2. The gas leaving the turbine part is further cooled by heat exchanger 3, using an
external cooling source. The closed cycle is rarely applied. The cycle is mostly
open, which then means that the compressor takes air from the atmosphere and
that the exhaust gas of the turbine, having passed through heat exchanger 1, is discharged into the atmosphere. In that case, there is no heat exchanger 3. In an open
cycle, heat exchanger 2 is always a combustion chamber, where the air is heated by
internal combustion. The gas passing through the cycle is converted from air into a
combustion gas. The atmosphere interferes as a component with the open cycle. The
exhaust gas is cooled in the atmosphere and combustion products are regenerated
by the flora of the earth. Many gas turbines do not feature a heat exchanger 1, as
sketched in Fig. 11.1. In its simplest form, the gas turbine consists of a compressor
part, a combustion chamber and a turbine part. The cycle is then termed a simple
cycle. Heat exchanger 1, if present, may take two forms. The term recuperator
Fig. 11.1 Scheme of a power gas turbine
11 Power Gas Turbines
used to drive vehicles, ships, propeller aircraft and helicopters. Gas turbine driven
vehicles are large power vehicles, as off-highway trucks, excavators, tanks and
train locomotives. Also ships requiring high propulsive power in limited available
space are gas turbine driven. This applies mainly to fast container ships, fast ferries, coast guard patrol boats and military ships like frigates and torpedo ships. Gas
turbines are also applied for aircraft propulsion. These are commonly called aero
gas turbines. Gas turbines for larger aircraft do not feature an outgoing shaft. The
turbine part drives a compressor part and a part for thrust generation by acceleration
of air, termed fan. The combustion gas leaving the turbine part is applied to generate
thrust as well. Aero gas turbines are discussed in Chap. 12. The term aero gas turbine is commonly applied to all turbines for aircraft propulsion, including outgoing
shaft machines for driving the propeller of a propeller aircraft or a helicopter rotor.
Figure 11.1 represents a closed cycle gas turbine. The gas delivered by the compressor is heated by two heat exchangers. Heat exchanger 1 extracts heat from the
exhaust gas of the turbine. Heat from an external source is added in heat exchanger
2. The gas leaving the turbine part is further cooled by heat exchanger 3, using an
external cooling source. The closed cycle is rarely applied. The cycle is mostly
open, which then means that the compressor takes air from the atmosphere and
that the exhaust gas of the turbine, having passed through heat exchanger 1, is discharged into the atmosphere. In that case, there is no heat exchanger 3. In an open
cycle, heat exchanger 2 is always a combustion chamber, where the air is heated by
internal combustion. The gas passing through the cycle is converted from air into a
combustion gas. The atmosphere interferes as a component with the open cycle. The
exhaust gas is cooled in the atmosphere and combustion products are regenerated
by the flora of the earth. Many gas turbines do not feature a heat exchanger 1, as
sketched in Fig. 11.1. In its simplest form, the gas turbine consists of a compressor
part, a combustion chamber and a turbine part. The cycle is then termed a simple
cycle. Heat exchanger 1, if present, may take two forms. The term recuperator
Fig. 11.1 Scheme of a power gas turbine