Oil Burner With Monitoring

BACKGROUND

This application relates to an oxy-fuel burner, and in particular a staged oxy-oil burner, configured with instrumentation to monitor the status and health of the burner, as well as burner operation, and to enable intelligent preventative maintenance to be conducted no sooner than necessary but prior to a failure or unforeseen shutdown condition.

For conventional burner systems, furnace operators determine a maintenance schedule on past experience, or on a regular calendar basis. This frequently result in a maintenance schedule that is overly aggressive, costing excess manhours and burner downtime, or is overly lax, failing to capture correctable burner issues before a failure occurs.

Systems exist for limited monitoring of various burner parameters, but none integrates this monitoring in a comprehensive way to enable predictive maintenance. For example, some existing systems require optical access of a flame, temperature sensors to prevent overheating, or pressure sensors to monitor flame instability. But none monitor combinations of parameters in a way that enables predictive maintenance.

SUMMARY

A staged oxy-fuel burner as described herein is configured with integrated sensors to measure several parameters that are useful in monitoring the health of the burner and in predicting the need for maintenance. For any staged oxy-fuel burner, those parameters may include, separately or in combination, the inlet fuel pressure, the oxygen feed pressure, the staging valve position, the fuel nozzle temperature, and the burner block temperature. For a staged oxy-oil burner, those parameters may include one or more parameters, separately or in combination, including but not limited to the inlet oil temperature, the inlet oil pressure, the atomizing oxidant (air or oxygen-enriched air or oxygen) pressure, the oxygen feed pressure, the staging valve position, the lance tip or atomizing nozzle temperature, and the burner block temperature. This information collected from these sensors can be used by operators/engineers directly, or by an automated monitoring and alerting system, to monitor the performance of the burner and identify any maintenance needs of the burner, for example to schedule maintenance and improve the burner operation.

Such instrumentation can be integrated into any burner, including a burner that uses one or more of gaseous fuel, liquid fuel, and solid fuel, and including a non-staged burner, a fuel-staged burner, an oxidant-staged burner, and a burner in which both fuel and oxidant are staged. It is understood that for each type of burner, the type, position, and quantity of sensors can be customized to correspond to the operational modes and parameters most relevant to that particular burner.

Various features are built into the burner so that the electronic monitoring does not interfere with normal operation and maintenance of the burner. The instrumentation is also protected so that it will continue to function for long periods of time in the type of harsh environments in which burners normally operate. In one embodiment, the electronics are battery powered and transmit data wireless for ease of installation and maintenance.

A burner with integrated sensors can be used as part of a system for remote tracking of burner parameters to enable real-time monitoring of burner performance and to assist in predictive maintenance by detecting changes in operation of the burner before a failure or shutdown occurs, such as is described in commonly owned patent application entitled “Remote Burner Monitoring System and Method” that is being filed concurrently herewith and is incorporated by reference herein in its entirety.

Aspect 1. An oxy-oil burner with monitoring, comprising: an oil lance having an oil nozzle at a tip end, and an oil inlet distal from the tip end; a primary oxidant passage surrounding the oil lance; a oil nozzle temperature sensor positioned in the oil nozzle at the tip end of the oil lance; an oil inlet temperature sensor positioned near the oil inlet; an oil pressure sensor positioned near the oil inlet passage; and an instrument enclosure for receiving data from the sensors; wherein the oil nozzle temperature, the oil supply temperature, and the oil supply pressure in combination are usable to indicate the presence or absence of an abnormal burner condition.

Aspect 2. The burner with monitoring of Aspect 1, wherein the abnormal burner condition includes a potential problem with the one or more of the oil nozzle, the oil supply system, the oil lance position relative to the primary oxidant passage, and the oil composition.

Aspect 3. The burner with monitoring of Aspect 1 or Aspect 2, wherein the oil nozzle is an atomizing nozzle, the burner further comprising: an atomizing gas inlet distal from the tip end of the oil lance; an atomizing gas pressure sensor positioned near the atomizing gas inlet; wherein the difference between the atomizing gas pressure and the oil pressure is usable to further indicate the presence or absence of an abnormal burner condition including a potential problem with one or more of the atomizing nozzle, the oil composition, and the oil temperature.

Aspect 4. The burner with monitoring of any of Aspects 1 to 3, further comprising: an oxidant pressure sensor positioned to sense oxidant pressure supplied to at least the primary oxidant passage; and wherein the oxidant pressure and staging valve position are usable to further indicate the presence or absence of an abnormal burner condition including partial obstruction of the primary oxidant passage.

Aspect 5. The burner with monitoring of any of Aspects 1 to 4, further comprising: a secondary oxidant passage spaced apart at a fixed distance from the primary oxidant passage; a staging valve for proportioning oxidant between the primary and secondary oxidant passages; a staging valve position sensor for sensing the relative proportion of oxidant being directed to the primary and secondary oxidant passages; wherein the staging valve position, in combination with the oxidant pressure, is usable to further indicate the presence or absence of an abnormal burner condition including one or more of a sub-optimal staging valve position and partial obstruction of one or both of the primary and secondary oxidant passages.

Aspect 6. The burner with monitoring of any one of Aspects 1 to 5, further comprising: a burner block having a hot face adjacent to the furnace; a burner block temperature sensor mounted in the burner block near the hot face; wherein the burner block temperature sensor is usable to further indicate presence or absence of an abnormal burner condition including one or more of potential block overheating and flame asymmetry.

Aspect 7. The burner with monitoring of any one of Aspects 1 to 6, further comprising: a position sensor for sensing the installation angle of the burner; wherein the installation angle of the burner is usable to further indicate whether the burner is installed at a desired orientation and/or slope with respect to the furnace.

Aspect 8. The burner with monitoring of any one of Aspects 1 to 7, further comprising: a temperature sensor for sending an internal temperature of the instrument enclosure; wherein the instrument enclosure internal temperature is usable to indicate potential overheating of electronic components in the enclosure.

Aspect 9. The burner with monitoring of any one of Aspect 1 to 8, further comprising: a unique identifier on the primary oxidant passage; and a unique identifier on the oil lance; wherein the primary oxidant passage identifier and the oil lance identifier are usable to tag data for analysis purposes.

Aspect 10. The burner with monitoring of any one of Aspects 1 to 9, the instrument enclosure comprising: a data collector programmed to provide power to individual sensors only when data is to be collected, based on one or both of a combination of sensed data and a periodic schedule, and taking into account the specific requirements of each of the individual sensors; and a transmitter for wirelessly transmitting sensor data from the data collector to a data center.

Aspect 11. The burner with monitoring of Aspect 10, the instrument enclosure further comprising: a local power generation system for powering the data collector, sensors, and transmitter.

Aspect 12. A method of determining an operating condition of an oxy-oil burner including an oil lance having a oil nozzle, a primary oxidant passage surrounding the oil lance, and a burner block having a face adjacent to the furnace, the method comprising: receiving data for burner parameters from one or more sensors selected from the group of temperature sensors, pressure sensors, flow sensors, position sensors, angle sensors, and combinations thereof; determining expected values for the burner parameters; comparing the received parameter data with the burner parameter expected values to determine a deviation in the burner parameter; and indicating that maintenance is required if the deviation in the burner parameter in a specified direction is greater than or equal to a specified threshold value.

Aspect 13. The method of Aspect 12, wherein the burner further includes a secondary oxidant passage spaced apart at a fixed distance from the primary oxidant passage and a staging valve for proportioning oxidant between the primary and secondary oxidant passages.

Aspect 14. The method of Aspect 12 or Aspect 13, further comprising: sensing an oil lance inlet pressure; sensing an oil inlet temperature; sensing an oil nozzle temperature; and determining based on the sense parameters whether the burner is in an abnormal operating condition including a potential problem with the one or more of the oil nozzle, the oil supply system, the oil lance position relative to the primary oxidant passage, and the oil composition.

Aspect 15. The method of any one of Aspects 12 to 14, wherein the oil nozzle is an atomizing nozzle, the method further comprising: sensing an atomizing gas inlet pressure; determining based on the difference between the atomizing gas pressure and the oil pressure whether the burner is in an abnormal operating condition including a potential problem with one or more of the atomizing nozzle, the oil composition, and the oil temperature.

Aspect 16. The method of any of Aspects 12 to 15, further comprising: sensing oxidant pressure supplied to one or both at least the primary oxidant passage; sensing the staging valve position; and determining based on the oxidant pressure and staging valve position whether the burner is in an abnormal operating condition including one or more of a sub-optimal staging valve position and partial obstruction of one or both of the primary and secondary oxidant passages.

Aspect 17. The method of any one of claims 12 to 16, further comprising: sensing a burner block temperature near the face; determining based on the burner block temperature the presence or absence of an abnormal burner condition including one or more of potential block overheating and flame asymmetry.

Aspect 18. An oxy-fuel burner with monitoring, comprising: a fuel passage having a fuel nozzle at a tip end and a fuel inlet distal from the tip end; a primary oxidant passage surrounding the fuel passage; a temperature sensor positioned in the fuel nozzle at the tip end of the fuel passage; and a fuel pressure sensor positioned near the fuel inlet.

Aspect 19. The burner with monitoring of Aspect 18, further comprising: a secondary oxidant passage spaced apart at a fixed distance from the primary oxidant passage; a staging valve for proportioning oxidant between the primary and secondary oxidant passages; an oxidant pressure sensor positioned upstream of the staging valve; and a staging valve position sensor for sensing the relative proportion of oxidant being directed to the primary and secondary oxidant passages.

Aspect 20. The burner with monitoring of Aspect 18 or Aspect 19, further comprising: a data unit for receiving data from the sensors, wherein the data unit is programmed to determine based on data received from one or more sensors the presence or absence of an abnormal burner condition.

Aspect 21. The burner with monitoring of any one of Aspects 18 to 20, further comprising: a position sensor for sensing the installation angle of the burner; wherein the installation angle of the burner is usable to further indicate whether the burner is installed at a desired orientation and/or slope with respect to the furnace.

Aspect 22. The burner with monitoring of any one of Aspects 18 to 21, further comprising: a unique identifier on the primary oxidant passage; wherein the primary oxidant passage identifier is usable to tag data for analysis purposes.

Aspect 23. An oxy-oil burner with monitoring, comprising: an oil lance having an atomizing nozzle at a tip end, and an oil inlet and an atomizing gas inlet distal from the tip end; a primary oxidant passage surrounding the oil lance; a secondary oxidant passage spaced apart at a fixed distance from the primary oxidant passage; a staging valve for proportioning oxidant between the primary and secondary oxidant passages; an atomizing nozzle temperature sensor positioned in the atomizing nozzle at the tip end of the oil lance; an oil supply temperature sensor positioned near the oil inlet; an oil pressure sensor positioned near the oil inlet passage; an atomizing gas pressure sensor positioned near the atomizing gas inlet; an oxidant pressure sensor positioned upstream of the staging valve; a staging valve position sensor for sensing the relative proportion of oxidant being directed to the primary and secondary oxidant passages; and a data unit for receiving data from the sensors, wherein the data unit is programmed to determine based on data received one or more sensors the presence or absence of an abnormal burner condition.

Other aspects of the invention are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is rear perspective view of an oil burner with monitoring for insertion into a burner block.

FIG. 1B is a rear perspective view of an oil burner with monitoring as in FIG. 1A inserted in a burner block.

FIG. 2 is a front perspective view of an oil burner similar to the burner in FIG. 1A inserted in a burner block, but without monitoring capabilities.

FIG. 3 is a rear perspective view of an oil lance for use in an oil burner with monitoring as in FIG. 1A.

FIG. 4 as a partial side view of an oil lance showing o-ring seals for maintaining and oil seal with the oil lance around a sensor access port.

FIG. 5 is a cross-sectional view of an oil burner with monitoring inserted in a burner block.

FIG. 6 is a graph showing exemplary pressure data comparing the difference between the oil inlet pressure and the atomizing gas inlet pressure for a fuel oil at different temperatures.

FIG. 7 is a graph showing exemplary pressure data comparing the difference between the oil inlet pressure and the atomizing gas inlet pressure for two fuel oil compositions and showing differences for one of those fuel oil compositions when the nozzle tip is partially clogged, and when a temperature excursion occurred.

FIG. 8 is a schematic showing components of a communication system for collecting, transmitting, and analyzing data collected from various sensors on a burner, and for providing local power generation to a data collector at each burner.

DETAILED DESCRIPTION

FIGS. 1A, 1B, 2, and 5 depict an embodiment of a staged oxy-oil burner 10 with integrated sensors, power supply, and communications equipment. Although an oxy-oil burner is described herein as an exemplary embodiment of a burner with monitoring, the same or similar communications equipment and methods, along with similar or analogous integrated sensors, customized to the configuration, design, and operational mode of the particular burner, can be used on burners that combust gaseous fuel with oxidant. In particular, with the exception of parameters that relate specifically to oil combustion, such as the oil and atomizing gas inlet pressures, all of the parameters and sensors described herein similarly apply to a burner for combusting any fuel, including gaseous fuel, solid fuel (e.g., petcoke) in a carrier gas, or liquid fuel. Additionally, in a staged oxy-fuel burner, one or both of fuel and oxidant (e.g., oxygen) is staged such that a primary stream participates in initial combustion while a secondary stream participates in delayed combustion away from the burner. For example, for oxidant staging, the oxidant is proportioned between a primary oxidant passage and a secondary oxidant passage, with the secondary oxidant being supplied to at least one secondary oxidant nozzle spaced apart from the primary oxidant nozzle(s) and fuel nozzle(s). Such staging may be accomplished by a staging valve upstream of the primary and secondary oxidant passages that proportions one incoming oxidant stream between the two passages. Alternatively, the flow to each of the primary and secondary oxidant passages may be independently controlled by a separate control valve. In other burners, fuel may be staged similarly, using either a staging valve or separate flow controls for primary and secondary streams. Further, in some burners, both fuel and oxidant may be staged.

The power supply is preferably a battery or local power generation for ease of installation and to avoid possible safety issues with wired power. The sensors may include, in any combination, temperature sensors, pressure sensors, position sensors, angle sensors, contact sensors, accelerometers, and flow sensors.

The burner 10, without sensors, is described in U.S. Pat. No. 8,172,566, which is incorporated herein by reference in its entirety. The burner 10 has a discharge end 51 and an inlet end 19. For convenience of description, the discharge end 51 is sometimes referred to herein as the front or forward direction of the burner 10, while the inlet end 19 is sometimes referred to as the rear or rearward direction of the burner 10. When the burner 10 is mounted in a furnace, the discharge end 51 faces the interior of the furnace.

The burner 10 includes a burner block 12, a burner body 14 positioned rearward from burner block 12 with respect to the furnace, and an instrument enclosure 16 positioned rearward with respect to the burner body 14. The burner body 14 includes a mounting plate 53 that is secured to the burner block 12. The burner block 12 has a front face 18 that, when mounted, faces into the furnace.

The burner block 12 includes a primary oxidant passage 30. In the depicted embodiment, the primary oxidant passage 30 has an elongated cross-sectional shape with a major axis (defining a width) longer than a minor axis (defining a height). In particular, the depicted primary oxidant passage 30 has the shape of a rectangle with semi-circular ends, and a width-to-height ratio from about 5 to about 30. However, in other embodiments, the primary oxidant passage 30 may have a circular, oval, ovalized rectangular, rectangular, or other shape.

An oil lance 20 is positioned within the primary oxidant passage 30 and has an oil nozzle 22 at its discharge end. In the depicted embodiment, the oil nozzle is an atomizing nozzle 22. The atomizing nozzle 22 is substantially surrounded by the primary oxidant passage 30 so that atomized fuel oil discharged from the nozzle 22 will mix intimately with the primary oxidant stream upon discharge. Preferably, the oil lance 20 and the nozzle 22 are separately manufactured parts that are joined together, for example by welding, to form a unitary lance with nozzle. In the depicted embodiment, the oil lance 20 substantially centrally positioned within the primary oxidant passage 30, although it is understood that the oil lance 20 may be located in a non-central provided the nozzle 22 is adapted to distribute the atomized oil to be adequately mixed with the primary oxidant stream for combustion. Alternatively, for an oxy-gas burner, a gaseous fuel passage can be positioned within the primary oxidant passage 30 in place of the oil lance 20.

The burner block 12 further includes a secondary oxidant passage 40 spaced apart by a fixed distance from the primary oxidant passage 30. In the depicted embodiment, the secondary oxidant passage 40 has an elongated cross-sectional shape with a major axis (defining a width) longer than a minor axis (defining a height), similar to the primary oxidant passage 30. In particular, the depicted primary oxidant passage 30 has the shape of a rectangle with semi-circular ends, and a width-to-height ratio from about 5 to about 30, which may be the same as or different from the width-to-height ratio of the primary oxidant passage 30. The major axis of the secondary oxidant passage 40 is substantially parallel to the major axis of the primary oxidant passage 30. However, in other embodiments, the second oxidant passage 40 may have a circular, oval, ovalized rectangular, rectangular, or other shape, and preferably but not necessarily approximately the same shape as the primary oxidant passage 30.

The primary oxidant passage 30 is fed oxidant from a primary oxidant conduit 32 positioned in the burner body 14 and extending into a rear portion of the burner block 12. Oxidant is fed through a pair of oxidant inlets 38 into an oxidant plenum 36 that in turn feeds the primary oxidant conduit 32. A diffuser 34 may be positioned between the oxidant inlets 38 and the oxidant plenum 36 to aid in straightening out the primary oxidant flow prior to entering the primary oxidant conduit 32.

The secondary oxidant passage 40 is fed oxidant from a secondary oxidant conduit 42 positioned in the burner body 14 and extending into a rear portion of the burner block 12. A staging valve 48 in the burner body 14 redirects a portion of the oxidant supplied by the oxidant inlets 38 into the secondary oxidant conduit 42. The term “staging ratio” is used to describe the proportion of oxidant that is redirected to the secondary oxidant conduit 42, and thus away from the primary oxidant conduit 32. For example, at a staging ratio of 30%, 70% of the oxidant is directed to the primary oxidant conduit 32 (and thus to the primary oxidant passage 30) as a primary oxidant stream and 30% of the oxidant is directed to the secondary oxidant conduit 42 (and thus to the secondary oxidant passage 40) as a secondary oxidant stream.

The oxidant gas fed to the oxidant inlets 38 may be any oxidant gas suitable for combustion, including air, oxygen-enriched air, and industrial grade oxygen. The oxidant preferably has a molecular oxygen (O2) content of at least about 23%, at least about 30%, at least about 70%, or at least about 98%.

The oil lance 20 extends rearward through the burner body 14 and through the instrument enclosure 16. Fuel oil is supplied to the oil lance 20 through an oil inlet 26. Due to the viscosity of fuel oil, it is typically necessary to also supply an atomizing gas to the oil lance 20 through an atomizing gas inlet 28. The atomizing gas may be any gas capable of atomizing the fuel oil as it exits the nozzle 22, including air, oxygen-enriched air, or industrial grade oxygen.

Various temperature sensors may be used for monitoring the temperature of burner components and for help determine fuel inlet conditions. In the depicted embodiment of FIGS. 1A, 1B, 2, and 5, a temperature sensor 102 is embedded in the atomizing nozzle 22 in the oil lance 20 for measuring the temperature at the discharge end of the oil lance 20. The temperature sensor may be a thermocouple or any other suitable sensor. The sensor 102 is fitted into a blind hole 103 in a rear side of the nozzle 22. Because the thermocouple must be removable for maintenance and replacement, it is not welded in place. Leads (not shown) connected to the temperature sensor 102 are routed back along the oil lance 20 to the instrument enclosure 16. To protect the leads 104 from abrasion, overheating, and other harsh conditions of the furnace environment, it is desirable to encase the leads. However, it is difficult from a manufacturing perspective to form a small diameter hole for a substantial portion of the length of the oil lance 20. Therefore, the leads are preferably recessed in a channel 106 along the length of the lance, and a sheath (not shown) is positioned over the channel 106 to protect the leads. In one embodiment, the sheath mates with an outer wall of the lance 20 to seal the leads and temperature sensor 102 from the furnace environment, to provide mechanical protection to the leads and temperature sensor 102, and to limit the flow disturbances of the primary oxidant stream flowing in the primary oxidant passage 30 and around the oil lance 20.

Temperature sensors may be placed on other components of the burner 10 to monitor operational parameters such as burner integrity, flame stability, flame position. For example, one or more temperature sensors 110 may be mounted in the burner block 12 near the front face 18. The temperature sensors 110 are preferably set back slightly from the front face 18 to protect them from the furnace environment. The temperature sensors 110 may be centered with respect to the primary oxidant passage 30, or offset from the minor axis centerline. and may be used to determine whether the flame is impinging on the burner block 12 or whether the flame is centered about the oil lance 20 or the primary oxidant passage 30. Temperature sensors may even be positioned in other locations of the furnace proximate to the burner for monitoring combustion conditions.

A temperature sensor 112 positioned in the oil stream near the oil inlet 26 to monitor the temperature of the oil being supplied to the burner 10. It is important to ensure that the viscosity of the oil stream will enable proper oil atomization, and the viscosity is a function of temperature as well as oil composition. Therefore, for any particular oil composition, an optimum temperature range can be determined for atomization.

The oil feed temperature sensor 112 must be able to measure the oil inlet temperature, but is preferably also positioned so as to permit lance cleaning without removing the temperature sensor 112. In the depicted embodiment of a rear portion of the oil lance 20 in FIG. 4, a sealing mechanism 61 is provided at the rear portion of the lance 20. The sealing mechanism 61 enables the temperature sensor 112 to be near the flowing oil stream in the lance 20 but also out of the way of the bore 21 of the lance 20, so that the bore 21 can be cleaned and so that the body 23 can be removed from the sleeve 64 without removing the temperature sensor 112. The sealing mechanism 61 includes a body 23 through which the bore 21 extends in a longitudinal direction, and a sleeve 64 surrounding the body 23. The body 23 includes a sensor well 68 surrounded to the front and rear by two pairs of o-rings 70 seated in o-ring grooves 72, which seal against an inner surface 74 of the sleeve 64. An access opening 69, or multiple such openings, enables oil flowing through the bore 21 to enter the sensor well 68. A sensor port 67 is located in the sleeve 64, and the temperature sensor 112 is secured (e.g., by threads or other mechanism) into the sensor port 67 so as to have its sensing tip flush with or slightly recessed from the inner surface 74 of the sleeve 64. Experiments have shown that a temperature sensor 112 mounted as shown and described is appropriately sensitive in responding to changes in oil inlet temperature. Consequently, the temperature sensor 112 is able to measure the oil temperature in the bore 21, or at least a temperature that has experimentally shown to be accurately representative of the oil temperature, while still permitting the body 23 to be removed from the sleeve 64 for cleaning without having to disturb the temperature sensor 112. Because the sensor well 68 extends around the entire circumference of the body 23, the body 23 may include multiple sensor ports 67 to enable mounting of multiple sensors. Also, multiple access openings 69 may be present to provide better uniformity of the oil in the sensor well 68. This arrangement allows the oil stream to contact the temperature sensor 112 while maintaining a seal with the sleeve 64 to prevent any oil leakage. Specifically, by mounting the temperature sensor 112 nearly flush with the bore so that the temperature sensor 112 is in contact with oil that is indicative of current oil temperatures. Also, by being flush or nearly flush, the temperature sensor 112 will not block physical components that are inserted into the bore 21 of the oil lance 20 for cleaning and to allow the body 23 to be removed from the oil lance 20 for cleaning. In one embodiment, the temperature sensor 112 may be fitted with a male NPT fitting to mate with a female NPT thread in the sensor port 67.

In the depicted embodiment, pressure sensors are also installed in the burner 10. A pressure sensor 114 is positioned in the oil stream near the oil inlet 26. The pressure sensor 114 may be mounted in the same sealing mechanism 61 as the temperature sensor 112, with the pressure sensor 114 being located in a different sensor port (not shown). Alternatively, the pressure sensor 114 may be mounted in a separate sealing mechanism having essentially the same construction as the sealing mechanism 61

In the embodiment of FIG. 5, a pressure sensor 116 is mounted in the atomizing gas stream near the atomizing gas inlet 28, and a pressure sensor 128 is mounted in the oxidant stream either near one of the oxidant inlets 38 or in the oxygen plenum 36 upstream of the staging valve 48. If desired, separate oxidant pressure sensors may be mounted in each of the primary oxidant conduit 32 and the secondary oxidant conduit 42 to detect the pressure of oxidant being supplied to each of the oxidant passages 30 and 40, respectively, in the burner block 12. The pressure sensors may be located inside or outside of the instrument enclosure 16, and are wired by cable for both power supply and signal transmission.

As shown, the instrument enclosure 16 includes a battery port 81 and an antenna 62 for wireless communication of data.

Note that similar configurations to the foregoing could be used to mount other sensors to monitor any of the feed streams.

Measuring the oil pressure can provide information about the flow resistance of the oil lance (e.g., decreased flow area due to coking or some other blockage will cause a pressure rise), the flowrate of the oil, and the viscosity of the oil (which is a function of temperature and composition). The oil pressure information is likely to be more useful when combined with other information (e.g., the oil temperature, the oil flowrate, the burner tip temperature, and data trending) in detecting maintenance needs of the oil lance.

Measuring the atomizing oxidant pressure also provides information about the oil flowrate and resistance and is therefore related to the oil pressure, but it is typically not the same and provides another element of information. Both of these instruments are located within the instrument box on the oil lance.

The oxygen pressure measurement provides information about the oxygen flowrate, flow resistance (i.e. blockage that may occur), and staging valve position.

The instrument enclosure 16, which is shown in partial cutaway in FIGS. 1A and 1B, is sealed and insulated to protect instrumentation contained therein from the dust and heat of a furnace environment. The instrument enclosure is positioned toward the rear 19 of the burner 10 to reduce the radiant heat energy received from the furnace. The instrument enclosure 16 includes at least a data collector 60, a power supply, and a transmitter 62 for sending data from the data collector to a data receiver 200 (which may collect and display data from multiple burners) located either locally or remotely.

The power supply is used to power the pressure sensors, the data collector, and the transmitter, and any other sensors and equipment requiring power. Preferably, the power supply is powered by a local battery that may or may not be charged via local energy harvesting or power generation to avoid having to wire outside power to the instrument enclosure 16. For example, local power generation may include using temperature gradients, mass flow, light, induction, or other means to generate sufficient power to support the sensors and other associated equipment in the instrument enclosure 16.

FIG. 8 is a schematic of an exemplary system for handling the burner data, it being understood that various alternative combinations of hardware, firmware, and software could be configured and assembled to accomplish the same functions. One or more burners 10 may be mounted in the furnace 70, each burner 10 having an instrument enclosure 16 as described above. In the schematic of FIG. 8, multiple burners 10 are mounted in the furnace 70. Each instrument enclosure 16 contains a data collector 60 for collecting and aggregating the data generated by each of the sensors on the burner 10, and a wireless transmitter 62 for transmitting the data from the data collector 60, as well as other components such as a power supply. The data collector 60 is programmable via one or more of hardware, firmware, and software, independently or in combination, to perform application-specific functions.

In an exemplary embodiment, the data collector 60 at each burner 10 aggregates data for that burner 10 using a highly configurable Wireless Intelligent sensor Node (WIN). The data collector 60 powers the various sensors associated with the burner 10, and is programmed to convert a battery voltage of between 3.2V and 6V, for example to the correct voltage required by each sensor (e.g., 12V). The battery voltage can be supplied by locally mounted batteries that are replaceable or that are charged by local power generation. In one embodiment, the sensors transmit analog output signals that are read via an analog to digital converter with a programmable gain amplifier to take into account the output range of each sensor. In another embodiment, the sensors transmit digital output signals that are scaled, or that may be scaled, based on the output range of each sensor.

The data collector 60 is also capable of reading digital sensors or indicators such as a serial number. An internal temperature sensor allows monitoring of the ambient temperature and thus cold junction compensation of thermocouples. An internal accelerometer allows the attitude of the node (and therefore what it is attached to) to be measured. Advanced power management is used to maximize battery life. In particular, the data collector 60 is programmed to power the sensors when measurements are to be taken, either based on a combination of sensed conditions or on a regular schedule.

The sensor measurements are consolidated, taking into account the gain of the amplifier taken, cold junction compensation, and any other relevant factors, and transmitted to a data receiving/processing center 200, preferably via a wireless link. In an exemplary embodiment, the wireless link uses the 2.4 GHz ISM band and the 802.15.4 standard as its physical layer and Medium Access Control (MAC). However, any other wireless link now known or later developed that is suitable for the operating environment could be used. The protocol uses a star network topology. Alternative frequencies and protocols are possible, including without limitation mesh network topologies. The 2.4 GHz band was chosen since it is a worldwide ISM band while most other ISM bands are country specific. The wireless link to the node is bidirectional to allow configuration of the node over the air. The data may be encrypted prior to transmission for security purposes. The data may be transmitted directly from the data collector 60 to the data center 200, or indirectly via one or more Wi-Fi repeaters depending on the distance and signal path between the burner 10 and the data center 200.

The data center 200 is configured to receive data from the individual burners 10, and may also be configured to transmit data to a cloud-based server which can then serve data, provide alerts, and perform any other computational function via the Internet or other network. The data center 200 may be a single piece of hardware or multiple cooperating pieces of hardware configured and programmed to perform all of the desired functions described herein.

Electrical power may be supplied to the data collector 60 by a local power generation system. FIG. 8 shows an exemplary local power generation system 208 to provide electrical power to the data collector 60. In the depicted embodiment, the local power generation system 208 includes a rechargeable battery 206 or super capacitor, and an energy harvester 204. The rechargeable battery 206 may include, for example, one or more lithium ion batteries or the like. Charging and discharging of the battery 206 is controlled by a battery supervisor 202, which is positioned as a hub between the data collector 60, the battery 206, and the energy harvester 204. The battery supervisor 202 can be configured to perform various functions, including but not limited to one or more of the following, alone or in combination: conditioning power flowing to and from the battery 206 and the energy harvester 204, maximum power point tracking to maximize harvested energy efficiency from the energy harvester 204, and permitting the data collector 60 to turn on only when there is sufficient energy available in the battery 206. Local power generation systems 208 as described herein may be used to respectively power individual data collectors 60 located at each burner 10, or one local power generation system may power one or more nearby data collectors 60. These local power generation systems can operate to store power during periods of low usage and release power during periods of high usage, thereby minimizing the required capacity of the energy harvester. In addition, similar local power generation systems 208 can be used to power one or more data centers 200.

Advanced power management helps ensure long-term operation of the system on limited battery or locally generated power supply. Power is supplied to a Wireless Intelligent sensor Node (WIN) that is highly configurable to provide the correct required voltage to each of the different sensors. Moreover, the WIN intelligently turns off power to individual sensors when they are not in use, collects data from the sensors when in use, and transmits the data at configurable time intervals. An indicator light shows the status of the system and also provides alerts. By powering the sensors only when they are used (e.g., on a predetermined time rotation to obtain periodic measurements), this conserves power from the power supply. However, it has been determined that some sensors, including but not limited to pressure sensors, may not give reliable data immediately after being powered up and do not respond well to being powered for only brief amounts of time. Therefore, the system requires both careful selection of sensors and specific configuration of the WIN to match the power up and power down cycles with the operating requirements of each sensor.

The data collector receives signals from all the sensors, and the transmitter sends the collected signal data to a data indicator where a user can view the status of the various parameters being measured.

In the depicted embodiment, the burner 10 also has a rotation sensor 124 on the staging valve 48 to detect the percent staging. The rotation sensor 124 could be a Hall effect type sensor, accelerometer type sensor, a potentiometer, optical sensor, or any other sensor that can indicate rotational position. Additional position and angle sensors may be used to determine the position and/or angle of the burner body 14 relative to the furnace or the burner block 12, the position and/or angle of the lance 20 relative to the burner body 14 or the burner block 12, the insertion depth of the lance 20, and any other angles or positions that may be relevant to the operation of the burner 10.

For example, position sensors on the oil lance 20 can be used to detect and verify correct insertion depth and to log the information for tracking performance. Angle sensors on the burner 10 can be used to ensure that the burner is installed properly. This could be for ensuring that the burner is seated properly against the mounting plate for seating positive seal. In addition it is sometime desirable to install the burner at a given angle with respect to horizontal. Other sensors such as contact sensors between the burner and mounting plate could be used to ensure proper mounting of the burner to the mounting plate. By using one or more such sensors (preferably at least two) the burner can do a check on its installation to ensure that it is not ajar and is indeed in contact with both sensors (for example, a top sensor and a bottom sensor, or a left sensor and right sensor, or all four positions).

Additional connection ports may be located on the oil lance 20, the burner body 14, and/or the burner block 12 to enable additional external sensors or other signals to be connected to the data collector for transmission to a data indicator.

In one embodiment of the system, each burner body 14 and each oil lance 20 has a unique identifier. This is useful since oil lances can be separated from the burner body and may be switched to different burner bodies. By incorporating a unique identifier on the burner body and lance, the communications equipment in the instrument box, which travels with the lance, can identify which burner body it is connected to for historical data archiving, trend analysis, and other reasons. This identifier could be RFID, a type of wireless transmitter, bar code, a one-wire silicon serial number, a unique resistor, a coded identifier, or any other identifying means.

Measuring the various temperatures, pressures, and positions of the burner and its components and feed streams and inputs from the other associated equipment including flow control skids, separately and in combination, can provide valuable information that enables an operator to perform preventive maintenance only when needed and to avoid costly unexpected failures or shutdowns.

In one example, high oil tip temperature along with higher than expected oil pressure and atomizing gas pressure may indicate that the oil nozzle is clogged or is starting to clog. This alerts an operator that maintenance should be performed soon so that the tip does not burn up in hot furnace.

The difference between the oil inlet pressure and atomizing gas inlet pressure can provide an estimate of the expected firing rate, since for a given firing rate, there would be an expected pressure difference between the oil and atomizing gas. However, this estimate of firing rate may be affected by clogging. Alternatively, or in combination with measuring the difference between the oil and atomizing gas pressures, the oxygen inlet pressure and staging valve position can be used to calculate the firing rate based on an assumed a stoichiometry, and this measurement is not typically affected by oil nozzle clogging. So for any firing rate, if the pressure difference between the oil and atomizing gas is more than expected (taking into account the oil viscosity based the measured oil temperature), this is an indication that some clogging is occurring and maintenance is needed.

FIG. 6 compares the pressure difference between the oil inlet and the atomizing gas inlet pressures as a function of firing rate for a known composition of fuel oil at three different oil temperatures. In all cases, the atomizing nozzle was clean and unobstructed. As can be seen from the data, the pressure difference is greater at all firing rates for the lower temperature oil, with the pressure difference becoming larger in both absolute and relative terms at the higher firing rates. Testing has shown that this pressure difference is a much better indicator of the health of the atomizing nozzle than the oil inlet pressure alone.

FIG. 7, on the same axes as FIG. 6, compares three situations at 175° F.: the triangular data points represent a first fuel and are the same data as the triangular data points on FIG. 6; the circular data points represent a second fuel having a more viscous composition at the same temperature conditions with a clean atomizing nozzle; and the diamond data points represent the first fuel but flowing through a partially obstructed atomizing nozzle. It can clearly be seen that the second fuel, due to its higher viscosity, exhibits a significantly higher pressure difference (between the oil inlet pressure and the atomizing gas pressure) than the lower viscosity first fuel, and that the pressure difference rises significantly when the atomizing nozzle is partially obstructed or clogged. Additionally, the diamond shaped data point that is circled in the top right of the graph occurred during a temperature excursion of the atomizing nozzle when the temperature had unexpectedly changed, thereby showing that multivariable monitoring that takes into account secondary effects can also be useful as an internal check on the proper operation of all of the sensors and the system.

Further, using any estimate of firing rate (however determined) provides an expected oil pressure. If the oil pressure is higher than the expected oil pressure then either some clogging is occurring or the oil viscosity is lower than expected. A higher than expected oil pressure combined with the oil inlet temperature would help determine whether the oil viscosity is low or if the oil nozzle is partially blocked.

If the oil pressure is as expected and the inlet oil temperature is as expected, than a higher tip temperature may indicate that the tip is inserted farther than design or that the flame is not where it is expected to be (see below for an example). Therefore, it is clear that there is a complex interplay between the various measured parameters to ascertain, for example, the reason for an elevated tip temperature or a lower than expected oil pressure or a higher than expected oil pressure. Note that, in addition to comparing these parameters on each burner, for example versus historical or predicted data, these parameters can also be compared across burners to detect abnormal operation of one of the burners and can be combined with other plant data. This determination can include a multi-variable analysis, for example as described in “A New Paradigm in Real Time Asset Monitoring and Fault Diagnosis, Neogi, D., et al., 2013 AIChE Annual Meeting, Conference Proceedings Presentation No. 268b (Nov. 5, 2013).

In another example, a higher than expected oxidant pressure may indicate a decrease in the oxidant flow area in the burner block 12. The expected oxidant pressure can be determined by other measured variables including flow control skid data. The oxidant pressure is a function of oxidant flow (or to a first approximation, firing rate for a known stoichiometry) and staging valve position. By estimating the oxidant flow based on the measured oil pressure (assuming a clean oil nozzle) or from the method described above, there is an expected oxidant pressure based on the staging valve position. If the oxidant pressure is higher than the expected oxidant pressure, that could indicate that the flow area of the oxidant is decreased either due to blockage of the burner block openings or some other opening. The burner block openings may be partially blocked by run down on the block face, slag, or other material that may have splashed or dripped onto the burner. If such partial blockage occurs undetected, it may lead to failure of the burner and/or burner block, so it is important to detect before such failure occurs. To more accurately determine the expected oxidant pressure, it may be useful to also determine the oxidant flow rate, for example via an oxidant flowmeter or to infer the oxidant flow rate using the burner firing rate (which may be determined using previously described methods) and stoichiometry.

In another example, one or more temperatures sensors 110 mounted near the face 18 of the burner block 12 can be used to detect flame detection, for example by comparing burner block temperatures above and below the exit of the oxidant and oil, or to the left and right of the exit of the oxidant and oil. These measurements may be particularly useful with regard to the top (primary oxidant and fuel) exit as compared with the secondary oxidant exit.

In another example, the staging valve position by itself may be used to determine that the burner settings are optimized and that operators/engineers are aware when something has changed on the burner settings. Typically, the staging valve position is set during startup or commissioning to optimize burner performance for the particular furnace and process. The staging valve position would not normally be changed after startup. However, sometimes a staging valve may be accidentally or intentionally turned to a non-optimal position, and it would be important to identify such a condition to ensure that the burner is operating as desired.

In another example, the inlet oil temperature may be used to estimate the oil viscosity at the atomizing nozzle 22. The viscosity is dependent on composition of the oil, so inlet oil temperature by itself cannot determine the viscosity, but it can provide information about the viscosity especially when combined with the inlet oil pressure (a function of the viscosity). This will let an operator know if the inlet temperature is appropriate and when combined with the pressure data possibly know if the oil composition has changed.

In another example, position and angle sensors can provide information about the orientation of the burner and whether it is installed properly, including whether the burner is level or at a desired slope or angle with respect to a furnace wall. Further, connection of sensor cables on the lance to the instrument enclosure that that the lance is connected to a burner and therefore installed in a furnace.

In another example, monitoring may help optimizing operating conditions of the burner to reduce pollutant formation such as nitrogen oxides (NOx) and to maximize flame quality by reducing or eliminating sooting.

The present invention is not to be limited in scope by the specific aspects or embodiments disclosed in the examples which are intended as illustrations of a few aspects of the invention and any embodiments that are functionally equivalent are within the scope of this invention. Various modifications of the invention in addition to those shown and described herein will become apparent to those skilled in the art and are intended to fall within the scope of the appended claims.

Oil Burner With Monitoring

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