KR20010102321A - Combustion unit for combusting a liquid fuel and a power generating system comprising such combustion unit - Google Patents

Abstract

The present invention relates to a combustion apparatus for burning liquid fuel, which has a fuel inlet, an air inlet, and a flue gas outlet connected to a combustion chamber for burning fuel, the fuel inlet being formed by gas formation in the atomized fuel. It is connected to at least one explosion spray device installed to make the atomized fuel fine, wherein the explosion spray device is preferably an explosion swirl spray device, while at least one gas turbine and at least one compression driven by the gas turbine An apparatus and a power generation system having at least one said combustion apparatus.

Description

Combustion unit for combusting a liquid fuel and a power generating system comprising such combustion unit}

In the combustion of liquid fuels, in particular gasoline and fuels for engines such as kerosene, diesel oil and methanol, it is important that during combustion the fuel is present as the smallest possible particles. The smaller the fuel particles, the more homogeneous the combustion product. More homogeneous combustion is associated with less CO emissions and generation as well as less CO emissions and emissions.

Therefore, the aim is to put the smallest possible fuel droplets in the combustion chamber, and the known combustion apparatus is characterized by having additional means for obtaining the smallest possible fuel droplets in the combustion chamber at the moment of combustion.

The present invention relates to a combustion device for burning liquid fuel and a power generation system having such a combustion device.

1 is a schematic diagram of an explosion vortex sprayer,

2 is a schematic view of a diesel engine according to the present invention with an exhaust turbine supercharger,

3 is a schematic view showing a modification of the diesel engine shown in FIG.

4 to 6 is a schematic diagram showing each of the combustion engine according to the present invention,

7 is a schematic diagram of a power generation system according to the present invention;

8 is a schematic view showing another power generation system according to the present invention according to the principle of the upper humidifying air turbine (hereinafter TOPHAT),

Figure 9 is a schematic diagram showing another power generation system according to the present invention according to the principle of the upper humidified air combustion engine (hereafter TOPHACE).

The present invention has a means for transferring very small liquid fuel particles (such as 1.2 μm, having a median size of less than 5 μm, usually less than 3 μm, preferably less than 2 μm) into the combustion chamber. It is an object of the present invention to provide a combustion device for burning liquid fuel. This can ensure a sufficient supply of such tiny liquid fuel particles, while the means for obtaining these tiny liquid fuel particles have a relatively simple structure and can be added to existing combustion apparatus in a relatively simple manner.

The object can be achieved by a combustion device for burning liquid fuel in accordance with the present invention, the combustion device having a fuel inlet, an air inlet and a flue gas outlet connected to a combustion chamber for burning fuel, the fuel The inlet is connected to at least one explosive atomizer installed so that the atomized fuel becomes fine due to gas formation in the atomized fuel.

The means for realizing very small liquid fuel particles consists of an explosion spray device.

All known types of nebulizers can in principle be used in the explosion spray device, for example vortex nebulizers and slotted nebulizers, hole nebulizers, tumbler or bowl nebulizers, and optionally pen nebulizers. What is important is that the atomizer produces a liquid fuel film or droplets as a gaseous medium under varying conditions, which in turn causes an explosion spray. Explosion spraying involves the liquid fuel entering the combustion chamber under certain conditions, resulting in boiling or droplets in the liquid fuel film or droplets due to the pressure drop across the sprayer. That is, gas formation occurs in liquid fuel. So-called flashing or condensation creates a fuel film or droplet that explodes or becomes fine due to sudden local boiling or gas condensation. This refinement causes very small droplets of fuel to be produced as a gaseous medium. The median size of the fuel particles is, after miniaturization, smaller than 5 μm, usually smaller than 3 μm, preferably smaller than 2 μm, such as 1.2 μm.

The explosion spray device does not have to deliver the liquid fuel sprayed directly into the combustion chamber. It is sufficient for the resulting droplets to finally enter the combustion chamber without unnecessarily large drop growth occurring as a result of coalescence.

The present invention can be used in the atomizing means of all types of atomizers as long as the atomizers can produce particles having the above medium size after miniaturization. In this regard, it is important that the explosion spray device be installed such that the atomized fuel becomes fine through the gas formation in the atomized fuel.

Preferably, an explosive vortex sprayer with a vortex sprayer is used, in which known vortex sprayer vortices are transferred to the liquid fuel in the vortex chamber and the swirling fuel exits the outlet opening. The outlet layer thickness of the fuel is a portion of the diameter of the outlet passage (eg 10%). Subsequent explosion micronization results in particles having a median size of 5 μm or smaller (depending on pressure drop and temperature and passage diameter).

In order to realize the miniaturization, it is important that the conditions under which the liquid fuel is sprayed (particularly changes in conditions) are optimized for miniaturization. Important conditions for flash evaporation are the temperature of the fuel, the spraying pressure at which the fuel is sprayed, the pressure drop during discharge, and the passage diameter. Therefore, it is preferable that the explosion spray device is provided with means for adjusting the temperature or spray pressure of the evaporating agent.

In the case of modifying the above-described combustion apparatus, it is possible to integrally form a configuration of a plurality of explosion spray apparatuses at a new or modified air inlet, or to have an explosion spray apparatus that goes directly to the combustion chamber. By having the exit passage of each explosion spray device in azimuth, it is possible to atomize the fuel to optimize the formation of a mixture of fuel and air for combustion. Vortex atomizers are particularly preferred, and because they have a very simple structure, slotted or hole atomizers can be easily miniaturized and installed in existing combustion apparatuses. Thus, a very large number of explosion spray devices can be incorporated without much modification of existing combustion devices, which provides great freedom in the choice of fuel flow rate for the combustion chamber. Modifications of existing combustion apparatuses enable these combustion apparatuses to be retrofitted at low cost and nevertheless achieve significantly improved combustion with low smoke and low NO _x emission characteristics.

As mentioned above, liquid fuel can be used as fuel, where the liquid state relates to the state of the fuel at the prevailing temperature and pressure at the fuel inlet. This means that fuel which is a gas at atmospheric conditions can be used. Fuels such as diesel oil and gasoline have a boiling range. This means that in order to realize the explosion spraying, the temperature must be selected from the boiling range and a significant instantaneous evaporation effect must occur. In diesel oil, this temperature can be chosen as 350 ° C, and in kerosene or gasoline a lower fuel temperature (250 ° C for kerosene and 150 ° C for gasoline) can be chosen. High fuel temperatures, such as 400 ° C., may be selected for low speed marine diesel engines. However, these temperatures can vary depending on the pressures used and the optional fuel additives that have a positive effect on the explosion spray. It can be seen that the combustion apparatus is preferably equipped with means for regulating the spray pressure and temperature of the fuel in order to realize an optimal explosion spray.

Further, preferably, if the temperature control means adjusts the temperature of the evaporating agent at or near the critical temperature, the evaporating agent will obtain 0 N / m ² or almost such surface tension. This means that the spray energy is no longer or rarely needed to spray the liquid, so that the droplet size is very small (where the median droplet size can be 0.1 μm), and optionally the use of other agents to reduce the surface tension is required. It means you can be gone.

In addition to the above physical conditions for refinement, refinement may be enhanced by chemical or physical additives to the fuel. Therefore, it is desirable to add an agent to the fuel that reduces the surface tension of the fuel, thereby reducing the energy required for miniaturization. Detergents and the like may be used as agents that reduce surface tension. Agents that reduce surface tension do not remain only on the surface of the fuel droplets, but are preferably distributed almost homogeneously through the fuel membrane or droplets. As such, the surface tension need not be reduced to a small extent as a result of diffusion after spraying and before miniaturization. Under these conditions, preference is given to using fatty acids, especially short fatty acids and optionally alcohols such as methanol and ethanol. The latter agent is particularly preferred because of its relatively low boiling point and good combustion. Thus, the combustion process is prevented from being negatively affected by these additives.

According to another embodiment, the fuel contains combustible or vaporizable materials that reduce the surface tension of the fuel or improve gas formation in the fuel as a result of the pressure drop across the atomizer. In particular, combustible or vaporizable materials having a boiling point lower than the boiling point of the fuel may be used here. In the case of boiling ranges of fuel and optionally evaporating agents, these ranges mean that the evaporating agents are chosen to fundamentally contribute to gas formation and ultimately fuel refinement. When multiple or mixed evaporating agents are used, the lowest boiling evaporable material first evaporates rapidly, forming a boiling drop due to the pressure drop as it passes through the explosion spray device, causing the liquid fuel to explode or drop. Finer. The mixture can be used, for example, diesel oil as fuel and water as evaporating agent. Superheated evaporating agents (water) can also be used as evaporating agents (such as water), in particular in oil-fired boilers generating steam. In this case, the fuel and the superheated water may be put into the boiler separately by the explosion spray. Here, an additional advantage is realized through the evaporation of water that the temperature of the mixture is lowered before combustion, during combustion and after combustion, which improves the performance of the combustion device and reduces the emissions of CO and NO _x .

The combustion device can be used for example in combustion engines such as gas engines, gasoline engines or diesel engines. In addition, the combustor may be combined with a power generating system, which includes a compressor driven by a gas turbine, and a system in which fuel and air compressed by the compressor are combusted and supplied to the gas turbine. A combustion device according to the invention is provided.

This is highly desirable in that an explosive atomizer sprays a determined evaporating agent (eg water) with a relatively high evaporation energy used in the compression device. As a result, quasi-isothermal compression is obtained and the compression operation is significantly reduced. When the combustion apparatus has a compression chamber and a combustion chamber, the explosion spray device for fuel may be connected to the combustion chamber, and the explosion spray device for the evaporative agent for evaporative cooling may be connected to the compression chamber.

Compression strokes of combustion engines and selective quasi-isothermal compression during combustion strokes and in some cases optimum combustion can occur. In addition, in the case of evaporative cooling, at least one pressure vessel is accommodated between the combustion chamber and the compression chamber of the combustion engine, which is in heat exchange contact with the combustion gas outlet of the combustion engine. Therefore, the heat compressed by the compressed air can be recovered from the heat of the flue gas. If the time in the pressure vessel is too short, multiple pressure vessels can be used side by side, or a relatively large pressure vessel can be combined with multiple combustion chambers.

The above and other features of the combustion apparatus and power generating system according to the invention are described in more detail below with reference to a number of embodiments given by way of example and not by way of limitation.

1 shows an explosion vortex sprayer 1 as used in the combustion apparatus according to the invention, in which the explosion vortex sprayer 1 has a fuel opening (or optionally an evaporating agent) tangential opening 4. A line 2 is supplied to the vortex chamber 5 as a medium. This liquid obtains the vortex movement 6 in the vortex chamber 5 and leaves the nebulizer 1 via the outlet opening (or passage). The swirling fuel is in the shape of a cone. Here, the thickness of the fuel layer is reduced and crushed into very small droplets as a result of miniaturization. When the existing liquid exhibits flash evaporation or gas condensation through sudden pressure drop, the thickness of the fuel layer is smaller than the diameter of the outlet opening 7 of the vortex chamber 5, after which the cone and the particles are very small. It can be clearly seen that the droplets become fine and so-called explosion sprays. The thickness of the conical layer and the size of the droplets formed depend on the degree of explosion spraying and the degree of gas formation in the conical layer. Important physical conditions are the pressure and temperature of the fuel and the prevailing pressure and temperature in the space in which the swirled and atomized fuel is delivered. Thus, the choice of these conditions can affect the number and size of fuel particles formed and atomized.

2 shows a diesel engine 8 according to the invention, which has six combustion devices or cylinders 9 according to the invention. The diesel oil is supplied by the pump 10 and the line 11 to the explosion spray device 12, which may consist of an appropriate number of explosion sprayers selected as shown in FIG. This diesel has the right temperature and pressure for explosion spraying. Air is supplied via line 13 to compressor 14 driven by gas turbine 16 via shaft 15.

Flue gas from the cylinder 9 is added to the gas turbine 16, which is fed to the gas turbine 16 via line 17 and to the chimney 19 via line 18.

The compressed air in the compressor 14 is supplied to the combustion chamber 21 of each cylinder 9 via the line 20.

FIG. 3 shows a diesel engine 22 corresponding to that of FIG. 2, wherein corresponding parts are designated with the same reference numerals. However, the first difference is that the air compressed in the compressor 14 is not supplied to the combustion chamber 21 through the line 20 but is supplied to the explosion spray device 12. This produces an optimal mix of fuel and air. If the air still contains evaporating agent particles (water particles), quasi-isothermal compression can still be achieved in the cylinder 9 consistently.

Secondly, the explosion spray device 23 is housed in the line 13. Here, water is supplied to the air through the explosion spray, whereby quasi-isothermal evaporation takes place in the compressor (14). The required water is supplied to the heat exchanger 25 via the line 24 and is in heat exchange contact with the flue gas exiting the gas ratio 16. The heated water is supplied to the explosion spraying device 23 under a constant pressure via the pump 26.

The diesel engines 8 and 22 shown in Figs. 2 and 3 can be used as marine diesel engines of low speed.

4 shows a combustion engine 27 according to the invention, which comprises a compression chamber 28 and a combustion chamber 29, which compression chamber 28 has an air inlet 30 with an inlet valve 31. And an explosion spray device (32) for supplying a coolant (for example, water) via the line (33). Thus, quasi-isothermal compression can be achieved by evaporative cooling. By means of an outlet 35 with a valve 34, the compression chamber 28 is connected to a pressure vessel 36 with a heat exchanger 37. The pressure vessel 36 is connected to the combustion chamber 29 via a line 38 and a valve 39, which in addition is an explosion spray device 40 and an ignition device for the fuel supplied via the line 41. (42) is provided. By the valve 43 and the outlet 44, the exhaust gas is discharged via the heat exchangers 45, 37, 46.

The operation of the combustion engine 27 is as follows. At a temperature of 1 bar and 27 ° C., water is sprayed through the explosion spray device 32 in the compression chamber 28, with quasi-isothermal compression taking place at 44 bar and 220 ° C. The valves 34 and 39 are opened and the pressure vessel 36 and the combustion chamber 29 are filled during the second half of the stroke of the piston 47. The valves 34 and 39 are then closed. The air in the pressure vessel 36 is heated to the exhaust gas passing through the heat exchanger 37. In the pressure vessel 36, the air is heated to a temperature of 300 ° C. and finally blown into the combustion chamber 29 via the valve 39.

At the same time fuel is injected via the explosion spray device 40, after which ignition and expansion occur in the combustion chamber 29. During the return stroke of the piston 48, the exhaust gas is discharged via the valve 43 and used for heat exchange between fuel and compressed air and water for injection.

In the combustion engine 29, it can be seen that the fuel is likewise injected through the explosion spray device 40, and the coolant is injected through the explosion spray device 32.

The use of the combustion engine 27 allows minimal compression to be carried out, while the recovery of low temperature heat can be realized for preheating of air, water or fuel.

If the time in the pressure vessel is insufficient for optimal heating of the compressed air, the pressure vessel is preferably implemented in the form of a number of pressure vessels connected side by side between the compression chamber 28 and the combustion chamber 29.

If quasi-isothermal compression is implemented by injecting a mixture of water and fuel (eg water and methanol), evaporative cooling can be added by extraction of the heat produced by the pyrolysis of the fuel. In order to carry out this pyrolysis of the fuel, a pyrolysis catalyst (e.g. CuO for methanol and zeolite for gasoline) needs to be incorporated into the pressure vessel. A moderate reaction time, usually around 1 second, and a sufficiently high pyrolysis temperature for methanol at 250-300 ° C. and gasoline at 475-675 ° C. are important.

By arranging the separation between the combustion chamber or expansion chamber and the compression chamber using a pressure vessel, optimization of energy efficiency can be realized in variable power requirements by the use of accumulated energy. Hybrid motors with a compressed air reservoir may optionally be used.

5 shows a combustion device 49 according to the invention.

Air is supplied via the inlet 51 via the rotating compressor 50, while a mixture of water and fuel is sprayed by the explosion spray device 52. Each via line 54, a combustion chamber 53 containing a compressed mixture of air and fuel is connected to a pressure vessel 58, while additional fuel is supplied via an inlet 55. The mixture is ignited using an ignition device 57. The exhaust gas exits the combustion chamber 53 through the outlet 57. Using the heat exchanger 59, heat exchange occurs with the mixture of air and fuel in the pressure vessel 58. By using a large pressure vessel 58 and a plurality of combustion chambers, it takes a great deal of time to heat the mixture in the pressure vessel using the exhaust gas.

FIG. 6 shows a combustion engine 60 having a cylinder 61 with a piston 62 in addition to an air inlet 63 and a flue gas outlet 65, which cylinder 61 further comprises this cylinder. A plasma electrode 66 is connected to a power electronics 68 that generates plasma at the head 61. During compression, the mixture of fuel and water is supplied via an explosion spray device 69, not shown in detail, for quasi-isothermal compression. Plasma arcs are continuously generated to heat the compressed air and ignite the fuel mixture, and after the expansion stroke of the piston 62 flue gas is discharged through the outlet 65 to drive the turbine 70, while partially Generates the power used by power electronics.

FIG. 7 shows a system 60 for generating power, which in turn has a compressor 61 driven via a shaft 62 by a gas turbine 63, which in turn drives a generator 64. Equipped.

Air is supplied to the compressor 61 via the line 65 and water is supplied to the explosion spray device 66 via the line 68 having the pump 67. The air compressed in the compressor 61 is supplied to the combustion device 69 according to the present invention, wherein the fuel preheated via the line 70 before being supplied to the combustion device 69 is pump 116 and a heat exchanger. 117 and the pump 118 are supplied at a constant pressure, and sprayed by the explosion spray device 71. The fuel is pressurized by the pump 116 and preheated by heat exchange with respect to the flue gas from the line 73 in the heat exchanger 117 to reach the critical temperature or above, or the fuel in the boiling range of the fuel. It is within the range of the critical temperature of the component. Flue gas via line 72 is supplied to turbine 63, and after expansion is released via line 73.

8 shows another system 74 for generating power in accordance with the present invention following the so-called TOPHAT principle. In the explosive device 75, the air 76 is provided in water droplets together with the water 77 supplied by the explosion spray. Air is supplied to a compressor 78 connected via a shaft 79 to a gas turbine 80 that drives the generator 81. Evaporative cooling of the droplets takes place in the compressor 78. The cold compressed air passes through the heat exchanger 83 via the line 82 and is supplied to the combustion device 84. The fuel is preheated at pre-pressure by the pump 120 in the heat exchanger 121 and placed under constant pressure by the pump 122, and in the explosion spraying device 93 supplied via the line 85 after expansion. Sprayed into the combustion device (84). The added fuel is at a constant pressure and temperature, so that a flash of fuel occurs when entering the combustion chamber of the combustion device 84, where a very fine spray of fuel is formed. Flue gas from gas turbine 80 passes through heat exchanger 83 via line 86 to make heat exchange contact with cold compressed air from compressor 78. Via line 87 the flue gas passes through heat exchanger 88 and condenser 89 on the way to chimney 92. In the condenser 89, water is condensed from the flue gas and guided through the heat exchanger 88 under constant pressure via the pump 90, after which the water 77 is exploded at a constant pressure and temperature. ) Is reached. Water condensed from the condenser 89 may optionally be continuously supplied with water via the line 91.

Finally, FIG. 9 shows a system 94 according to the invention for generating power in accordance with the TOPHACE principle.

Water (140-250 ° C., 150 bar) is fed to the explosion spray device (96) via a pump (95), likewise air (15 ° C.) is supplied via line (97). The air from the explosion spray device 96 reaches the compressor 98 operating at an efficiency of 0.8. Compressed air (140 ° C.) is supplied to the heat exchanger (100) via a line (99) in order to exchange heat with the flue gas of the combustion engine (101). The combustion engine has four cylinders 102, the air inlets 103 of which are connected to line 99 via a valve 104. The flue gas outlet 105 of each cylinder 102 passes through the heat exchanger 100, is transferred through the heat exchanger 107 via the line 106, and through the condenser 89 to the chimney 92. Enter In the condenser 89, a condensate 108 is formed, which is pre-pressurized by the pump 110 after passing through the water cleaner 109, and is supplied to the pump 95 via the heat exchanger 107. Supplied and pressurized.

Fuel is supplied to each cylinder 102 via a pump 111, a line 117, an explosion spray device 112, and a valve (not shown). This fuel is preheated to or below the critical temperature before being sprayed into the explosion spraying unit 112, or preheated within the range of the critical temperature in the boiling range.

In the recovery part 100, the air is heated from 140 ° C. to 377 ° C., while the flue gas from the cylinder 102 is recooled from 465 ° C. to 210 ° C. This air is supplied to the cylinder 102 at a pressure of 9 bar and the atomized fuel is injected. The cylinder 102 also includes an igniter 119 that ignites the mixture in each cylinder 102. The cylinders 102 are each provided with pistons 113, which are connected to the shaft 114 of the compressor 98 via a 1: 5 gear system 115 and the other side of the generator 116. It is connected to the shaft 114 connected to.

Under ideal conditions, the system 94 generates 226 kW of power at 64% efficiency, while the known device according to Atkinson principle generates only 170 kW of power at 48% efficiency.

Claims (12)

A fuel inlet, an air inlet and a flue gas outlet connected to a combustion chamber for burning fuel, And the fuel inlet is connected to at least one explosive atomizer installed so that the atomized fuel becomes fine due to gas formation in the atomized fuel. The combustion device as set forth in claim 1, wherein said explosion spraying device is an explosion swirl spraying device. 3. Combustion device according to claim 1 or 2, characterized in that the explosion spray device comprises means for adjusting the temperature or spray pressure of the fuel. 4. The combustion apparatus according to claim 3, wherein said temperature control means adjusts the temperature of the fuel at or above or below the critical temperature of the fuel. 5. Combustion apparatus according to any one of claims 1 to 4, wherein the fuel comprises an agent that reduces the surface tension of the fuel. 6. Combustion apparatus according to claim 5, wherein the agent which reduces the surface tension contains a combustible material or a vaporizable material. 7. Combustion apparatus according to any one of the preceding claims, wherein the fuel is a mixture of a fuel and an evaporating agent having a boiling point lower than that of the fuel. 8. Combustion apparatus according to claim 7, wherein the evaporating agent is water. 9. Combustion apparatus according to any one of the preceding claims, characterized in that the explosion spray device is housed in a combustion chamber and optionally a compression chamber of the combustion apparatus. 10. A combustion apparatus according to claim 9, wherein at least one pressure vessel in heat exchange contact with the flue gas outlet is located between the compression chamber and the combustion chamber. 11. Combustion apparatus according to claim 10, wherein the catalyst for pyrolyzing the fuel is located in a combustion chamber. 12. A power generation system having at least one gas turbine, at least one compression device driven by the gas turbine, and at least one combustion device as described in claims 1-11.