Abstract:
A combustion system of a composite heat carrier generator comprises combustion and vaporization chambers. The combustion chamber comprises a main body and a head portion connected thereto. The head portion comprises an outer shell, a cyclone, and fuel receiving, fuel spray nozzle, water receiving, and air receiving nozzles. The fuel receiving and fuel spray nozzles are connected. The air receiving nozzle forms an air inlet cavity in communication with the fuel spray nozzle and the cyclone. The cyclone includes a pre-combustion chamber facing the fuel spray nozzle and a groove. The pre-combustion chamber receives a mixture of fuel and air, and the cyclone groove introduces air.

Description:
TECHNICAL FIELD 
       [0001]    The present disclosure relates to a composite heat carrier generator and in particular, to a combustion apparatus of a composite heat carrier generator. 
       BACKGROUND 
       [0002]    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. 
         [0003]    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. 
         [0004]    However, since some oil field wells are up to 2,000 meters 0562 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. 
       SUMMARY 
       [0005]    The technical problem to be solved by the present disclosure is providing a combustion apparatus of a composite heat carrier generator, in order to adapt to the requirements for a higher combustion temperature and pressure. 
         [0006]    The technical solution adopted by the present disclosure to solve the above-mentioned technical problem is a combustion apparatus 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, and a combustion cavity is formed in the inner bush; 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 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. 
         [0007]    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. 
         [0008]    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. 
         [0009]    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. 
         [0010]    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 
         [0011]    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. 
         [0012]    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. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    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: 
           [0014]      FIG. 1  is a schematic diagram of a combustion apparatus of a composite heat carrier generator according to an embodiment of the present disclosure. 
           [0015]      FIG. 2  is an enlarged view of a section taken along A-A of  FIG. 1 . 
           [0016]      FIG. 3  is an enlarged view of part I of  FIG. 1 . 
           [0017]      FIG. 4  is a left side view of  FIG. 1 . 
           [0018]      FIG. 5  is an enlarged view taken along B-B of  FIG. 4 . 
           [0019]      FIGS. 6-8  are respectively perspective and sectional views of a fuel spray nozzle according to a first embodiment of the present disclosure. 
           [0020]      FIGS. 9 and 10  are respectively structural schematic diagrams of a fuel spray nozzle according to a second embodiment of the present disclosure. 
           [0021]      FIGS. 11-15  are structural schematic diagrams of a fuel spray nozzle according to a third embodiment of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]    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. 
         [0023]      FIG. 1  is a schematic diagram of a combustion apparatus of a composite heat carrier generator according to an embodiment of the present disclosure.  FIG. 2  is an enlarged view of a section taken along A-A of  FIG. 1 . Referring to  FIGS. 1-2 , a combustion apparatus  10  of a composite heat carrier generator of this embodiment comprises a head portion  100 , a combustion chamber  200  and a vaporization chamber  300 . The head portion  100  is provided with inlets for various combustion raw materials, such as fuel, air, and water. The combustion chamber  200  has a combustion cavity  201  therein, and an outer shell  202  outside the combustion cavity  201 . The vaporization chamber  300  has a vaporization cavity  301  therein, and an outer shell  302  outside the vaporization cavity  301 . The tail end of the vaporization chamber  300  is provided with a composite heat carrier outlet. 
         [0024]    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 . 
         [0025]    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 . 
         [0026]    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  FIG. 4 . The cyclone  107  is disposed at the rear end of the head portion  100 . The outer peripheral wall of the cyclone  107  is provided with a spiral cyclone groove  171  along a circumferential direction, and a pre-combustion chamber  172  facing the outer shell  101  of the head portion  100  is formed in an inner cavity of the cyclone  107 . 
         [0027]    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 . 
         [0028]      FIG. 3  is an enlarged view of part I of  FIG. 1 .  FIG. 5  is an enlarged view of a section taken along B-B of  FIG. 4 . Further referring to  FIGS. 3 and 5 , the air receiving nozzle  104  forms an air inlet cavity  141  on part of outer walls of the fuel receiving nozzle  102  and the fuel spray nozzle  103 . The air inlet cavity  141  is provided with an air inlet  142 . A shell wall of a rear section of the outer shell  101  is provided with a plurality of air channels  111 . A head end of the air channel  111  is in communication with the air inlet cavity  141 , and the terminal end thereof is divided into two branches, with one branch being an atomization air hole  112  for conveying air to the fuel spray nozzle  103 , and the other branch being a cooling air hole  113  for conveying air to the cyclone groove  171  of the outer peripheral wall of the cyclone  107 . 
         [0029]    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 . 
         [0030]    Further referring to  FIGS. 6-8 , a spray nozzle pipeline  131  is provided at the center of the fuel spray nozzle  10 , and a front end of the spray nozzle is provided with a plurality of spray nozzle atomization holes  132  extending into the interior of the fuel spray nozzle  103 . For example, the spray nozzle atomization holes  132  can be four in number, and are symmetrically arranged about the spray nozzle center. 
         [0031]    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 . 
         [0032]    Referring back to  FIG. 1 , in addition to the aforementioned outer shell  202 , the housing of the combustion chamber  200  has an inner bush  203 . A water spacer sleeve  204  is formed between an outer peripheral wall of the inner bush  203  and an inner peripheral wall of the outer shell  202 . A spiral cooling channel is formed in the water spacer sleeve  204  and used for conveying cooling water. The water spacer sleeve  204  is in communication with the water receiving nozzle  106  of the head portion  100 . An inner peripheral wall of the inner bush  203  is further provided with a plurality of spray holes  211 , the spray holes  211  being in communication with the water spacer sleeve  204 . 
         [0033]    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 . 
         [0034]    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. 
         [0035]    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. 
         [0036]    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. 
         [0037]    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. 
         [0038]    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. 
         [0039]      FIGS. 9 and 10  are structural schematic diagrams of a fuel spray nozzle according to a second embodiment of the present disclosure. The combustion apparatus of the present disclosure can not only use diesel oil as fuel, but also use crude oil as fuel. What is required is only replacing the fuel receiving nozzle and the spray nozzle. Compared with the embodiments shown in  FIGS. 6-8 , the fuel spray nozzle  103  of this embodiment is provided with another group of spray nozzle atomization holes  135  on the outer edge face of the fuel spray nozzle, near the edge. The spray nozzle atomization holes  135  are in communication with the fuel spray holes  133 . It can be seen from  FIG. 10  that a first group of spray nozzle atomization holes  132  located at the center of the outer edge face of the fuel spray nozzle  103  comprises 2 holes, and a second group of spray nozzle atomization holes  135  located at the edge of the outer edge face of the fuel spray nozzle  103  comprises 6 holes. Moreover, the diameter of the spray nozzle atomization holes  132  of the first group is smaller than that of the spray nozzle atomization holes  135  of the second group, and this change is to adapt to the fuel/air spray ratio for crude oil. 
         [0040]      FIGS. 11-15  are respectively structural schematic diagrams of a fuel spray nozzle according to a third embodiment of the present disclosure. The combustion apparatus of the present disclosure can not only use diesel oil as fuel, but also use natural gas as fuel. What is required is only replacing the fuel receiving nozzle and the fuel spray nozzle. It is to be noted that the part of the outer edge face of the fuel spray nozzle close to the edge is provided with a group of swirl holes  136 . These swirl holes  136  are also in communication with the annular groove  134 , and a vortex can be formed in the pre-combustion chamber when air is sprayed into the pre-combustion chamber via the swirl holes  136 , so that an ignition is easier. 
         [0041]    Compared with the prior art, the beneficial effects of the various embodiment of the present disclosure are: 
         [0042]    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. 
         [0043]    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. 
         [0044]    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.