GB2446650A - Water augmented power enhancement of internal combustion or gas turbine engines - Google Patents

Abstract

A small quantity of superheated water is injected into the cylinder of an i.c. engine, fig. 1, timed to occur during the normal combustion phase. An injector is supplied with water pressurised by a pump and heated by heat exchange with exhaust gases. Alternatively, the heat transfer takes place surrounding the jet pipe or combustion chamber of a gas turbine engine, fig. 3, with continuous injection of superheated water immediately ahead of the first stage of turbine stator blades. Part of the energy in the exhaust gases is thus recovered and converted into useful work.

Description

Water augmented power enhancement for internal combustion engines.

This mvention relates to supplementing the power available in the normal internal combustion engine cycles by increasing the pressure or volume or both of the gasses at that part of the cycle where energy is converted into mechanical work.

The combustion cycle in an internal combustion prime mover relies on air being compressed to a pressure where fuel is introduced and burnt efficiently, creating combustion gasses that produce an increase in volume and/or pressure. The energy so created in the combustion space is then converted into mechanical work by acting on pistons or turbine blades before being exhausted to atmosphere.

A proportion of the energy released from the fuel is lost to atmosphere in the heat of the exhaust gasses and also radiated from the combustion containment spaces. Part of this lost energy is recovered and converted into useful work.

The advantage being proposed is that in addition to the normal combustion process, water is preheated using waste heat from combustion. This heat is transferred to the water through an exhaust heat exchanger and at the same time pressurised by means of a pump to maintain the water in liquid form. This high pressure water is released as superheated atomized water into the engine system during or immediately aller the combustion of the fuel. In the case of a piston engine, the lower pressure in the cylinder allows the water to convert to superheated steam, thus adding to the overall increase in volume and/or pressure and thereby increasing the amount of mechanical energy that can be extracted. Similarly, in a gas turbine the increase in volume can enable the turbine to extract a greater amount of energy or create a higher thrust. The fuel efficiency of the prime mover is thus enhanced with a small addition to the water vapour content of the exhaust.

The advantage of this system is that the introduction of high pressure, high temperature water during the combustion phase of an internal combustion prune mover will increase the proportion of energy that can be converted into useful work from the fuel supplied. It can be applied to all forms of engine where there is sufficient waste heat from the cooling and exhaust systems. The extra power output does not increase the harmful products of combustion. Conversely, for a given power harmful gasses are reduced.

The invention is now described by way typical examples of piston and turbine engines.

Figure 1 shows a typical cross-section through upper cylinder and piston at the instant fuel is ignited.

Figure 2 shows a typical cross-section through upper cylinder and piston when superheated water is added.

Figure 3 shows a simplified cross-section through a typical gas turbine.

In figw 1 a cylinder bead is shown with an additional means (A) of injecting a small quantity of superbeated water, timed to ocair during the normal combustion phase. The injector is supplied with water that is pressurized by a suitable pump and passed through a heat exchanger nsfcrring heat from exhaust gasses. Figure 2 illustrates the injector which atomises the superheated water (B) into the combustion space. The micro droplets of water enable a higher rate of conversion to steam and maintain a higher cylinder pressure for a longer period of täne during the working stroke of the cycle.

In figure 3 the heat transfer (A) is Illustrated taking place surrounding thc jet pipe or combustion chamber, with continuc*is injection of superheated water taking place immediately ahead of the first stage of turbine stator blades.

The high pressure necessary to ensure water is maintained in a liquid form until injected, is created by the use of a mechanical pump driven from the prime mover.

Injection can also be in advance of combustion producing an increase in the voiwne flow from which higher mechanical power can be extracted. 3)

Claims (9)

Claims.

1. A water injection system that increases the volume of hot gasses in the operating cycle of an internal combustion engine, enabling more useful work to be extracted.

2. A water injection system that can increase the pressure of the hot gasses in the operating cycle of an internal combustion engine, enabling more useful work to be extracted.

3. A water injection system that can utilize waste heat from an mteznal combustion engine exhaust systeni

4. A water injection system that can utilize waste heat from the combustion space containment area in an internal combustion engine.

5. A water injection system that increases the overall thermal efficiency of internal combustion engines.

6. A water cction system that reduces the volume of pollutant exhaust gasses for a particular power output.

7. A water mjection system that increases the power available from a quantity of fueL

8. A water injection system that maintains pressure and volume for a longer period during the power extraction part of an engine combustion cycle.

9. A water jection system that can increase the thrust available from a gas tuii,ine for quantity of fuel, thereby increasing the specific power.