Patent Application
20160076344
The present disclosure relates to a composite heat carrier generator and in particular, to a combustion system of a composite heat carrier generator.
Injection of saturated water steam into an oil layer for the thermal production of thick oils is one of the methods commonly adopted in various countries of the world, and has achieved very good oil production effect and economic benefits. A device for generating saturated water steam is called as a wet saturated water steam generator. The wet saturated water steam generator subjects fuel and air to a low-pressure combustion in a combustion chamber, and heats water in a water pipe to make it vaporize to generate high-pressure saturated steam. The pressure of the steam can be up to 20 MPa (2900 psi), and this pressure can be used for injecting the steam into an oil layer. However, combustion products generated by the device are directly emitted to the atmosphere, which not only pollutes the environment, but also carries away about 10% fuel heat. Moreover, the main components in the combustion products are carbon dioxide and nitrogen, both of which are very useful substances for the tertiary production from thick and thin oil layers, and in the oil production from oil fields, sometimes carbon dioxide alone is injected, and sometimes nitrogen gas alone is injected.
In order to completely utilize the combustion products, a composite heat carrier generator is developed. The composite heat carrier generator subjects fuel and air to a high-pressure combustion (the combustion pressure can be up to 20 MPa (2900 psi)) in a combustion chamber, generating a high-temperature high-pressure fuel gas, by means of which, water sprayed at the rear end of the combustion chamber is vaporized into steam. The mixture of fuel gas and steam is called as a composite heat carrier. The pressure of the composite heat carrier can be up to 20 MPa (2900 psi), and the temperature thereof can be up to 350 degrees Celsius (662 degrees Fahrenheit) The composite heat carrier is directly injected by means of its own pressure into an oil layer via a thermal production well head and an oil pipe. Since in the composite heat carrier, carbon dioxide dissolves the crude oil, the nitrogen gas elastically drives the crude oil, and the steam has a thermodynamic action on the crude oil, the crude oil production rate can be improved by about 10% over the current case.
However, since some oil field wells are up to 2,000 meters (6562 feet) deep, a higher injection pressure is needed, i.e. the injection pressure is close to the critical pressure (22.565 MPa (3,272.8 psi), and the combustion temperature will be a high temperature above 2000 degrees Celsius (3632 degrees Fahrenheit), which poses higher demands on the ignition of the device, combustion chamber sealability, service life, reliability, maintainability and the like.
The technical problem to be solved by the present disclosure is providing a combustion system of a composite heat carrier generator, in order to adapt to the requirements for a higher combustion temperature and pressure.
The technical solution adopted by the present disclosure to solve the above-mentioned technical problem is a combustion system of a composite heat carrier generator, comprising a combustion chamber and a vaporization chamber, the combustion chamber comprising a combustion chamber head portion and a combustion chamber main body, the vaporization chamber being connected to a rear end of the combustion chamber main body, and the combustion chamber head portion being connected to a front end of the combustion chamber main body, wherein a housing of the combustion chamber main body comprises an outer shell and an inner bush, a combustion cavity is formed in the inner bush, a spiral cooling channel for cooling water to flow through is formed between the outer shell and the inner bush, and an inner peripheral wall of a rear section of the inner bush is provided with a plurality of spray holes penetrating through the cooling channel and the combustion cavity, to allow cooling water to be sprayed into the combustion cavity; and the combustion chamber head portion comprises an outer shell, a fuel receiving nozzle, a fuel spray nozzle, an air receiving nozzle, a spark plug, a water receiving nozzle and a cyclone; the fuel receiving nozzle is connected to the fuel spray nozzle, and is inserted substantially axially into a through-hole at the center of the outer shell of the combustion chamber head portion; the air receiving nozzle is sheathed on the outside of the fuel receiving nozzle and the fuel spray nozzle to form an air inlet cavity between the air receiving nozzle and part of outer walls of the fuel receiving nozzle and the fuel spray nozzle; the air inlet cavity is in communication with the fuel spray nozzle and the cyclone, respectively; the spark plug is inserted into the outer shell of the combustion chamber head portion; the water receiving nozzle is inserted into the outer shell of the combustion chamber head portion and in communication with the cooling channel; the interior of the cyclone is provided with a pre-combustion chamber facing the fuel spray nozzle, and an outer peripheral wall of the cyclone is formed with a cyclone groove, wherein the pre-combustion chamber is in communication with the fuel spray nozzle to receive a mixture of fuel and air, the cyclone groove is in communication with the air inlet cavity to introduce air, and the mixture and the air subsequently enter the combustion cavity.
In an embodiment of the present disclosure, the outer shell of the combustion chamber head portion is provided with a plurality of air channels, a head end of each of the air channels is in communication with the air inlet cavity, and a tail end thereof is divided into a plurality of atomization air holes and a plurality of cooling air holes, with each of the atomization air holes being in communication with each of the air channels and the fuel spray nozzle, and each of the cooling air holes being in communication with each of the air channels and the cyclone groove.
In an embodiment of the present disclosure, a spray nozzle pipeline is provided at the center of the fuel spray nozzle, an axial front end face of the fuel spray nozzle is provided with a plurality of spray nozzle atomization holes which penetrate into of the fuel spray nozzle and are in communication with the spray nozzle pipeline.
In an embodiment of the present disclosure, an outer edge face of the fuel spray nozzle is provided with an annular groove, the annular groove is in communication with each atomization air hole and each spray nozzle atomization hole, respectively, to allow air to enter each spray nozzle atomization hole via each atomization air hole and be mixed with the fuel entering each spray nozzle atomization hole via the spray nozzle pipeline.
In an embodiment of the present disclosure, the fuel is diesel, each spray nozzle atomization hole leads to the axial front end face of the flue spray nozzle from the annular groove, and the spray nozzle pipeline is in communication with each spray nozzle atomization hole via a plurality of fuel spray holes
In an embodiment of the present disclosure, the fuel is crude oil, each spray nozzle atomization hole is a first spray nozzle atomization hole and leads to the axial front end face of the flue spray nozzle from the annular groove, and the part of the axial front end face of the spray nozzle close to the edge is further provided with a plurality of second spray nozzle atomization holes penetrating into the fuel spray nozzle, with each second spray nozzle atomization hole being in communication with the oil spray pipeline via a plurality of fuel spray holes.
In an embodiment of the present disclosure, the fuel is natural gas, each spray nozzle atomization hole leads to the axial front end face of the fuel spray nozzle from the annular groove, the spray nozzle pipeline is in communication with each spray nozzle atomization hole via a plurality of fuel spray holes, and the part of the axial front end face of the spray nozzle close to the edge is further provided with a plurality of swirl holes, with each swirl hole being in communication with the annular groove.
In order to allow the above-mentioned objects, features and advantages of the present disclosure to be more easily understood, particular embodiments of the present disclosure are described in detail below in conjunction with the drawings, in which:
Claimed subject matter is now described with reference to the drawings, and throughout the figures, identical elements are provided with identical reference signs. In the following description, for the purpose of explanation, numerous particular details are stated in order to provide a thorough understanding of the claimed subject matter. However, obviously, the subject matter may be practiced without these particular details.
A front end of the combustion chamber 200 is connected to the head portion 100, and a rear end thereof is connected to the vaporization chamber 300. By way of example, the head portion 100 and the combustion chamber 200 can be connected in such a way that the head portion 100 is inserted at a front end of the outer shell 202 of the combustion chamber 200. A seal 221 is inserted between the outer shell 101 of the head portion 100 and the outer shell 202 of the combustion chamber 200 for sealing. And at the connection position, coupling flanges 222, double-end studs 223 and nuts 224 are used to tightly fix the two outer shells together. In addition, a seal 320 is inserted between the outer shell 202 of the combustion chamber 200 and the outer shell 302 of the vaporization chamber 300 for sealing. And at this connection position, coupling flanges 321, double-end studs 322 and nuts 323 are used to tightly fix the two outer shells together. In an embodiment, lens washers are used as the seals 221 and 320.
The head portion 100 comprises the out shell 101, a fuel receiving nozzle 102, a fuel spray nozzle 103, an air receiving nozzle 104, a spark plug 105, a water receiving nozzle 106 and a cyclone 107. The fuel receiving nozzle 102 and the fuel spray nozzle 103 are connected as one. The fuel receiving nozzle 102 is at the front end, and is responsible for inputting a fuel, such as diesel oil. The fuel spray nozzle 103 is at the rear end, and is responsible for spraying out the fuel. The fuel receiving nozzle 102 and the fuel spray nozzle 103 are substantially axially arranged on the head portion 100, and inserted in a center through-hole 110 of the outer shell 101. A seal 121 is inserted at the front end of the fuel receiving nozzle 102. In an embodiment, a lens washer is used as the seal 121.
The air receiving nozzle 104 is sheathed on outer walls of the fuel receiving nozzle 102 and the fuel spray nozzle 103, for inputting air. The spark plug 105 and the water receiving nozzle 106 are inserted on a shell wall of the outer shell 101. The relative relationship of the fuel spray nozzle 103, the spark plug 105 and the water receiving nozzle 106 can be seen in
Threaded connection and gasket sealing can be used for all of the fuel spray nozzle 103, the spark plug 105 and the water receiving nozzle 106 with respect to the outer shell 101.
A seal ring 122 is arranged between an outer peripheral edge of the air receiving nozzle 104 and the outer shell 101. A seal ring 123 is also arranged between an outer peripheral edge of the fuel spray nozzle 103 and the outer shell 101.
Further referring to
These spray nozzle atomization holes 132 are in communication with the spray nozzle pipeline 131 via fuel spray holes 133. An outer edge face of the fuel spray nozzle 103 is further provided with an annular groove 134. The atomization air holes 112 arranged on the outer shell 101 are in communication with the annular groove 134. The annular groove 134 is in communication with the spray nozzle atomization holes 132, so that air enters the spray nozzle atomization holes 132, is mixed with fuel entering from the fuel spray holes 133, and then is sprayed out of the opening located at a front end face of the spray nozzle atomization holes 132.
Referring back to
A seal ring 124 is further disposed between the inner bush 203 of the combustion chamber and the outer shell 101 of the head portion 100.
During combustion, fuel enters a burner from the fuel receiving nozzle 102, and is sprayed out of the fuel spray nozzle 103. Specifically, fuel enters the spray nozzle atomization holes 132 after passing through the spray nozzle pipeline 131 and the fuel spray holes 133 in sequence. On the other hand, air enters via the air receiving nozzle 104, and is distributed to the atomization air holes 112 and the cooling air holes 113 via the air inlet cavity 141, with most of the air being distributed to the cooling air holes 113. Air from the atomization air holes 112 further enters the spray nozzle atomization holes 132, is atomized and mixed with the fuel, such as diesel oil, and then travels to the pre-combustion chamber in the cyclone 107. The spark plug 105 ignites a mixture of fuel and air, so as to combust the mixture. Air from the cooling air holes 113 enters the cyclone 107 and flows along the cyclone groove 171 in the outer peripheral wall of the cyclone 107 into the combustion chamber 200, to collide, mix and after-combust with fuel gas being combusted in the pre-combustion chamber, achieving a sufficient combustion. Then a high-temperature fuel gas formed by the combustion enters a blending region 206. In addition, cooling water enters the burner from the water receiving nozzle 106, and cools the combustion chamber 200 along the spiral cooling channel of the water spacer sleeve 204. The water increases in temperature after cooling and is then sprayed into the blending region 206 via the spray holes 211. The cooling water sprayed into the blending region 206 is mixed with the high-temperature fuel gas, and enters the vaporization chamber 301 to form a composite heat carrier.
When the present embodiment operates, high-pressure air passes through the fuel spray nozzle 103 to form primary air, and through the cyclone 107 to form secondary air. The primary air is sprayed out via the four spray nozzle atomization holes 132 of the fuel spray nozzle 103, and the axial velocity of high-pressure air sprayed from every two symmetrical spray nozzle atomization holes 132 is reduced due to the collision, and the radial velocity thereof increases. Hence, the high-pressure air which has passed through the fuel spray nozzle diffuses towards the wall face in the combustion chamber 200, ensuring a reliable ignition and a stable combustion. The secondary air forms swirling air of a certain swirling intensity after passing through the cyclone 107, so that the mixing of fuel and air is more sufficient, ensuring a sufficient combustion.
It is to be mentioned that, part of the air entering from the air receiving nozzle 104 firstly enters the pre-combustion chamber via the atomization air holes 112, and is combusted with the fuel sprayed from the fuel spray nozzle 103. The temperature of the fuel-rich fuel gas is thus lower than the fuel gas temperature in the case of a complete combustion, protecting the inside of the head portion from burning out. The remaining air flows out of the cooling air holes 113 in the housing wall of the head portion 100, and flows along the cyclone groove 171 in the outer peripheral wall of the cyclone 107 into the combustion chamber, to collide, mix and after-combust with the fuel-rich gas which enters the combustion chamber after being combusted in the pre-combustion chamber, achieving a sufficient combustion.
In an embodiment, each component of the head portion 100, such as the air receiving nozzle 104, the fuel receiving nozzle 102, the fuel spray nozzle 103, the water receiving nozzle 106, the cyclone 107, etc., is movably connected to the outer shell 101 by means of an insertion connection or threaded connection, so that the maintenance and replacement of each of the components can be realized very conveniently, expanding the range of usage.
The air stream flowing through the cyclone groove 171 in the outer peripheral of the cyclone 107 is skillfully utilized, with an air film cooling being formed between the outer peripheral of the cyclone 107 and the inner bush 203 of the combustion chamber. Hence, it is possible to not only prevent overheating of the seal ring 124 between the inner bush 203 of the combustion chamber and the outer shell 101 of the head part 100, but also prolong the service life of the pre-combustion chamber by means of the air cooling effect.
Compared with the prior art, the beneficial effects of the various embodiment of the present disclosure are:
1. In the present disclosure, the high-pressure air passes through the cyclone into the combustion chamber via the cyclone, which can preheat air, reduce the temperature of the housing of the combustion chamber, reduce heat loss, and improve heat efficiency; in addition, since the combustion speed is accelerated after air is heated, the combustion efficiency can be improved.
2. The present disclosure adds cooling air holes in the end face of the head portion of the combustion chamber in order to cool the end face of the housing of the head portion, so that it can be ensured that flames at the root part are away from the end face of the head portion of the combustion chamber even if the operation is under an ultra-high pressure state, the housing of the head portion will not easily crack, and the service life is prolonged.
Although the present disclosure has been described with reference to the present particular embodiments, the ordinary skilled in the art is to recognize that these embodiments are only for illustrating the present disclosure, and that various equivalent changes or replacements can be made without departing from the spirit of the present disclosure; hence, changes and variations to the above-mentioned embodiments within the true spirit scope of the present disclosure will all fall into the scope of the claims of the present application.
