The following includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art nor material to the presently described or claimed inventions, nor that any publication or document that is specifically or implicitly referenced is prior art.
The present invention relates generally to the field of heating systems and more specifically relates to heat generators to heat gas or liquid material in a flow structure.
Fuel-fired heaters have applications in many industries. For example, the process of hydraulically fracturing, or “fracking” an oil well involves pumping a fluid slurry into the well bore at sufficient pressure so as to fracture the producing formation, thereby creating conductive flowpaths for the oil. In many cases, fracturing water must be heated to optimize the fracking process. During hydraulic fracturing, a single well may consume as much as eight-million gallons of heated water. The fuel needed to produce this volume of hot feed water represents a significant percentage of the overall production cost.
A common byproduct of crude-oil fracking is the production of natural gas. Many production sites are unable to direct all of the natural gas coming off a well into distribution pipelines, which may be at full capacity. An operator may have no choice but to add a flare to the well site to burn the excess natural gas.
Many fracking operations utilize large diesel-fired water heaters to produce the heated water required during the process. Unfortunately, these diesel-fired units are unable to utilize the essentially no-cost supply of natural gas available at many production sites.
Most recent advancements in hydraulic fracturing have been made in drilling and extraction technology rather than support services such as water heating. A need clearly exists for new systems and methods relating to the conversion of existing diesel-fired water heaters to operate on the plentiful low-cost natural gas available at many well sites. Furthermore, a system and method allowing the beneficial utilization of waste natural gas would be more environmentally friendly and efficient to operate.
Several attempts have been made to solve the above-mentioned problems such as those found in U.S. Pub. No. 2016/0305222 to Briggs. The device of Briggs relates to a wellhead gas heater. The described wellhead gas heater includes systems and methods that may provide a wellhead gas burner to burn wellhead gas produced from a wellhead to heat water and/or other chemicals used in hydrocarbon production and/or well completion processes, including, but not limited to hydraulic fracturing (fracking). The wellhead gas burner may include a pressure regulator and an expansion chamber that permit the wellhead gas burner to continuously operate and accommodate wellhead gas pressure fluctuations. The wellhead gas burner may also be configured as a primary heat source and integrated with a traditional propane/diesel gas burner system configured as a supplemental heat source. The wellhead gas burner may also be mounted to a mobile superheater truck. This art is representative of well site heating systems. However, the device of Briggs fails to disclose or suggest the particular combination of structures and arrangements of the presently disclosed system.
In view of the foregoing disadvantages inherent in the known heating systems art, the present invention provides novel heat generators to heat gas or liquid material in a flow structure. The general purpose of the present invention, which will be described subsequently in greater detail is to provide a liquid to gaseous fuel conversion system relating to the conversion of a liquid-fuel combustion heater to a combustion heater using at least one gaseous fuel. The system may include a gas train including a gas inlet configured to receive gaseous fuel from at least one gaseous-fuel source, at least one pressure regulator configured to regulate the pressure of the incoming gaseous fuel, at least one manual shutoff valve configured to allow manual shutoff incoming gaseous fuel, at least one safety shutoff valve, a solenoid valve configured to provide automated initiation and shutoff of the incoming gaseous fuel, and an automatic burner management controller configured to at least control the operation of the solenoid valve and the ignition source, and a gaseous-fuel burner assembly adapted to replace a liquid-fuel burner of the liquid-fuel combustion heater. The gaseous-fuel burner assembly may include an air-conducting channel configured to conduct a moving stream of air. A gaseous-fuel nozzle configured to inject the gaseous fuel into the moving stream of air to form a moving air-fuel combustion mixture may be disposed within the air-conducting channel. The gaseous-fuel nozzle may have a set of nozzle turning vanes configured to induce a vortex within the moving air-fuel combustion mixture.
In addition, the gaseous-fuel burner assembly may include an ignition source configured to ignite the moving air-fuel combustion mixture. The system may include a burner mount configured to assist mounting of the gaseous-fuel burner assembly within the liquid-fuel combustion heater using at least one original mounting point of the liquid-fuel burner. The system may also include an access plate configured to provide access to the gaseous-fuel burner assembly. The ignition source may include a pilot and a high voltage sparker to light the pilot. The gas train may further include a pilot circuit configured to supply the gaseous fuel to the pilot. The air-conducting channel may further include a set of channel-mounted turning vanes configured to induce an initial vortex within the moving air-fuel combustion mixture prior to passing the nozzle turning vanes and may also include at least one Venturi section of reduced cross-sectional area. The Venturi section may be configured to increase the velocity of the moving stream of air passing through the gaseous-fuel nozzle. The access plate may be removably mountable to an end wall of the combustion heater. The access plate may include at least one passage configured to pass the gaseous fuel from the gas train through the wall of the combustion heater to the gaseous-fuel burner assembly and at least one passage configured to pass the gaseous fuel from the gas train to the pilot.
The gaseous-fuel nozzle may include a central hub configured to receive the gaseous fuel. A set of radially-disposed gas-conduction tubes configured to conduct the gaseous fuel outwardly from the central hub may be placed in fluid communication with the central hub, wherein each gas-conduction tube of the set includes a plurality of discharge apertures configured to discharge the gaseous fuel into the moving stream of air. The nozzle turning vanes may be mounted to the gas-conduction tubes. Also, it provides such a system further including a kit including a set of installation instructions.
In accordance with another preferred embodiment hereof, this system provides a method relating to providing a set of components used to convert a liquid-fuel combustion heater to a combustion heater using at least one gaseous fuel. The method may include the steps of; providing a gas train including a gas inlet configured to receive gaseous fuel from at least one gaseous-fuel source, at least one manual shutoff valve configured to allow manual shutoff incoming gaseous fuel, and at least one pressure regulator configured to regulate the pressure of the incoming gaseous fuel. In addition, the method may include the step of providing a gaseous-fuel burner assembly adapted to replace a liquid-fuel burner of the liquid-fuel combustion heater, the gaseous-fuel burner assembly including an air-conducting channel configured to conduct a moving stream of air. A gaseous-fuel nozzle configured to inject the gaseous fuel into the moving stream of air to form a moving air-fuel combustion mixture may be located within the air-conducting channel. The gaseous-fuel nozzle may have a set of nozzle turning vanes configured to induce a vortex within the moving air-fuel combustion mixture, an ignition source configured to ignite the moving air-fuel combustion mixture, and a burner mount configured to assist mounting of the gaseous-fuel burner assembly within the liquid-fuel combustion heater using at least one original mounting point of the liquid-fuel burner.
The method may also include the step of providing a set of instructions describing the removal of liquid-fuel components of the liquid-fuel combustion heater and providing a set of instructions describing the installation of gaseous-fuel components replacing the liquid-fuel components. In addition, it may provide such a method further including the steps of arranging the ignition source to comprise a pilot and a high voltage sparker to light the pilot. In addition, such a method may further include the steps of providing within the gas train, a pilot circuit configured to supply the gaseous fuel to the pilot. Moreover, it may provide such a method further including the step of arranging the air-conducting channel to comprise a set of channel-mounted turning vanes configured to induce an initial vortex within the moving air-fuel combustion mixture prior to passing the nozzle turning vanes.
Such a method may further include the steps of providing at least one Venturi-constriction section configured to increase the velocity of the moving stream of air passing through the gaseous-fuel nozzle. Further, it may provide such a method further including the steps of providing within the gas train, a solenoid valve configured to provide automated initiation and shutoff of the incoming gaseous fuel and providing an automatic burner management controller configured to at least control the operation of the solenoid valve and the ignition source. Even further, it may provide such a method further including the step of providing at least one safety shutoff valve within the gas train. Providing a replacement access plate configured to provide access to the gaseous-fuel burner assembly and arranging the replacement access plate to be removably mountable to an end wall of the combustion heater.
Furthermore, it may provide such a method further including the steps of arranging the replacement access plate to include at least one passage configured to pass the gaseous fuel from the gas train through the wall of the combustion heater to the gaseous-fuel burner assembly, and at least one passage configured to pass the gaseous fuel from the gas train to the ignition source. Even further, it may provide such a method further including the step of providing the combustion heater with the gas train and gaseous-fuel burner assembly pre-installed. Even further, it may provide such a method further including the steps of conducting operational testing of the combustion heater by at least one testing authority testing the combustion heater and receiving at least one testing certification from the at least one testing authority.
For purposes of summarizing the invention, certain aspects, advantages, and novel features of the invention have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any one particular embodiment of the invention. Thus, the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein. The features of the invention which are believed to be novel are particularly pointed out and distinctly claimed in the concluding portion of the specification. These and other features, aspects, and advantages of the present invention will become better understood with reference to the following drawings and detailed description.
The figures which accompany the written portion of this specification illustrate embodiments and method(s) of use for the present disclosure, heat generators to heat gas or liquid material in a flow structure, constructed and operative according to the teachings of the present disclosure.
The various embodiments of the present invention will hereinafter be described in conjunction with the appended drawings, wherein like designations denote like elements.
As discussed above, embodiments of the present disclosure relate to fired industrial heaters and more particularly to a liquid to gaseous fuel conversion system as used to convert a liquid-fuel combustion heater to a combustion heater using at least one gaseous fuel.
For the last 50 to 60 years, feed-water heaters used in hydraulic fracturing oil recovery have operated on diesel fuel. The current market seeks more economical and emissions friendly equipment. Generally speaking, the presently-disclosed system is arranged to convert diesel-fired industrial-process heaters to operate on natural gas, propane, or other gaseous fuels. This allows operator to retain their existing fired heaters while taking advantage of the more economical and emissions friendly natural gas and related gaseous fuels.
During performance testing, unmodified diesel-fired units consumed diesel fuel at a rate of about 200 liters per hour. At the time of testing, the cost of diesel fuel averaged about one dollar per liter. The converted gas-fired heaters are configured to operate on natural gas, which is often supplied at a much lower cost at petroleum well sites. The system produces operational performance substantially similar to diesel, but is more cost effective, and better for the environment. Key features of the present system include:
Referring now more specifically to the drawings by numerals of reference there is shown in
An important benefit provided by the present system is that a majority of the components of the liquid-fuel combustion heater 101 are retained after completion of the conversion to gaseous fuel. As illustrated in
The general procedure for conversion begins with the removal of the external diesel-fuel components 105. These component may include the diesel-fuel nozzle, the diesel-fuel igniter electrodes, and the ignitor coil. The outer faceplate 107 is then removed allowing the internal diesel firepot 113 to be extracted, as shown. In a typical conversion procedure, the associated diesel-fuel supply assembly 109 is also removed. The diesel-fuel supply assembly 109 may include the diesel-fuel supply lines, valves, filters, pumps, storage tanks, and related components. It is noted that the full conversion may be completed without removing the heater from its transport truck, trailer, or other operational placement. Liquid-fuel combustion heaters suitable for conversion using liquid to gaseous fuel conversion system 100 include heating units produced by Fabmaster Ltd. of Edmonton, Alberta.
In the example liquid-fuel combustion heater 102 of the present disclosure, a rear bulkhead wall 140 of the inner draft chamber 110 is formed by a rigid stainless steel fire ring 142 engaging the proximal end of a helical coil heat exchanger 144 of the internal heat exchange assembly 112 (see also
The rear bulkhead wall 140 contains a series of outwardly-projecting mounting studs 146 normally used to secure the existing diesel firepot 113 to the rear bulkhead wall 140 prior to removal. During the conversion, these mounting studs 146 are again be used to mount the replacement gaseous-fuel burner assembly 124 to the rear bulkhead wall 140, as will be described in
The system may include a burner mount 148 to assist mounting of the gaseous-fuel burner assembly 124 within the inner draft chamber 110 using at least one original mounting point 150 of the diesel firepot 113 (liquid-fuel burner of
The new outer access plate 126 may be removably mountable to an outer wall 136 of the combustion heater 102 to provide access to the gaseous-fuel burner assembly 124. The outer access plate 126 may utilize the mounting-bolt locations of the original outer faceplate 107, as shown in
The outer access plate 126 may also include a barrel-shaped “squeeze ring” having a series of air-directing vanes 158 surrounding the gaseous-fuel burner assembly 124, as shown. The air-directing vanes 158 function to concentrate the air coming from the forced-air mechanical blower 114 into the gaseous-fuel burner assembly 124. The “squeeze ring” assembly may be used in both the diesel and gas fuel applications.
The modified combustion heater 102 implements a unique fuel/air mixing arrangement that promotes efficient combustion of the gaseous fuel 103. The gaseous-fuel burner assembly 124 may include an air-conducting channel 160 configured to conduct a moving stream of air 115, as shown. The air-conducting channel 160 is configured to introduce the fuel and air into the heater at increased velocity. A two-stage air-management process creates high levels of vortex turbulence proceeding and during combustion.
A gaseous-fuel nozzle 162 may be disposed within the air-conducting channel 160, as shown. The gaseous-fuel nozzle 162 may be configured to inject the gaseous fuel 103 into the moving stream of air 115 to form a moving air-fuel combustion mixture 117. In addition, the gaseous-fuel burner assembly 124 may include an ignition source 164 (see again
The gaseous-fuel nozzle 162 may include a central hub 172 configured to receive the gaseous fuel 103. The gaseous-fuel nozzle 162 may have a set of nozzle turning vanes 168 configured to induce a secondary vortex flow 123 within the moving air-fuel combustion mixture 117. A set of radially-disposed gas-conduction tubes 174 configured to conduct the gaseous fuel 103 outwardly from the central hub 172 may be placed in fluid communication with the central hub 172, wherein each gas-conduction tube 174 of the set includes a plurality of discharge apertures 176 configured to discharge the gaseous fuel 103 into the moving stream of air 115. The nozzle turning vanes 168 may be mounted to the gas-conduction tubes 174 in the vortex-inducing angular orientations shown.
Assembly and installation of the of the gaseous-fuel components 122 generally follows the sequence of mounting the gaseous-fuel nozzle 162 inside the air-conducting channel 160 of the gaseous-fuel burner assembly 124, mounting the gaseous-fuel burner assembly 124 within the inner draft chamber 110, installing the new access plate 126 over the draft chamber 110 followed by installation of the natural gas/propane gas train 130.
The gas train 130 may further include at least one pressure relief valve 190. The gas train 130 may be compactly arranged to allow the assembly to be mounted to the side of the side of the combustion heater 102.
The burner management controller 178 may provide burner ignition and flame fail sensing as well as monitoring of valve status. The monitoring/control nodes 177 may utilize thermocouple inputs, which can be utilized for temperature control. A burner management controller suitable for use with the present system may include the ACL CSC 400 Burner Management Systems/Combustion Safety Controller produced by ACL Manufacturing Inc. of Alberta, Canada.
Referring again to
The liquid to gaseous fuel conversion system 100 may be manufactured and provided for sale in a wide variety of sizes and shapes for a wide assortment of applications. For example, the liquid to gaseous fuel conversion system 100 may include combustion heater 102. Upon reading this specification, it should be appreciated that, under appropriate circumstances, considering such issues as design preference, user preferences, marketing preferences, cost, structural requirements, available materials, technological advances, etc., other kit contents or arrangements such as, for example, including more or less components, customized parts, components for other heater manufacturers, parts that may be sold separately, etc., may be sufficient.
Referring now to
In addition, the method 500 may include step two 502, providing a gaseous-fuel burner assembly 124 adapted to replace the liquid-fuel burner (diesel firepot 113) of the liquid-fuel combustion heater 101, the gaseous-fuel burner assembly 124 may include the air-conducting channel 160 configured to conduct a moving stream of air 115. A gaseous-fuel nozzle 162 configured to inject the gaseous fuel 103 into the moving stream of air 115 to form a moving air-fuel combustion mixture 117 may be located within the air-conducting channel 160. The gaseous-fuel nozzle 162 may have a set of nozzle turning vanes 168 configured to induce a vortex within the moving air-fuel combustion mixture 117, an ignition source 164 configured to ignite the moving air-fuel combustion mixture 117, and a burner mount 148 configured to assist mounting of the gaseous-fuel burner assembly 124 within the liquid-fuel combustion heater 101 using at least one original mounting point 150 of the diesel firepot 113. The method 500 may also include the step three 503, providing a set of instructions 202 describing the removal of diesel-fuel components 105 of the liquid-fuel combustion heater 101 and providing a set of instructions 202 describing the installation of gaseous-fuel components 122 replacing the diesel-fuel components 105.
In addition, the method 500 may further include the step four 504, arranging the ignition source 164 to comprise a pilot 156 and a high voltage sparker 166 to light the pilot 156. In addition, method 500 may further include the step five 505, providing within the gas train 130, a pilot circuit 182 configured to supply the gaseous fuel 103 to the pilot 156. Moreover, method 500 may further include the step six 506, arranging the air-conducting channel 160 to comprise a set of channel-mounted turning vanes 168 configured to induce an initial vortex within the moving air-fuel combustion mixture 117 prior to passing the nozzle turning vanes 168.
Method 500 may further include the step seven 507, providing at least one Venturi section 170 configured to increase the velocity of the moving stream of air 115 passing through the gaseous-fuel nozzle 162, step eight 508, providing within the gas train 130, at least one solenoid valve 180 configured to provide automated initiation and shutoff of the incoming gaseous fuel 103 and providing an automatic burner management controller 178 configured to at least control the operation of the solenoid valve 180. Even further, method 500 may include the step nine 509 of providing at least one safety shutoff valve 188 within the gas train 130, providing a replacement access plate 126 configured to provide access to the gaseous-fuel burner assembly 124, and arranging the replacement access plate to be removably mountable to an outer end wall of the combustion heater 102.
Furthermore, method 500 may further include the step ten 510, arranging the replacement access plate to include at least one passage 152 configured to pass the gaseous fuel 103 from the gas train 130 through the wall of the combustion heater 102 to the gaseous-fuel burner assembly 124, and at least one passage 154 configured to pass the gaseous fuel 103 from the gas train 130 to the ignition source 164. Even further, method 500 may include step eleven 511, providing the combustion heater 102 with the gas train 130 and gaseous-fuel burner assembly 124 pre-installed. Even further, method 500 may further include the step twelve 512, conducting operational testing of the combustion heater 102 by at least one testing authority testing the combustion heater 102 and receiving at least one testing certification from the at least one testing authority. It should be noted that steps eleven and twelve are optional steps and may not be implemented in all cases. Optional steps of method of use 500 are illustrated using dotted lines in
It should be noted that the steps described in the method of use can be carried out in many different orders according to user preference. The use of “step of” should not be interpreted as “step for”, in the claims herein and is not intended to invoke the provisions of 35 U.S.C. § 112 (f). Upon reading this specification, it should be appreciated that, under appropriate circumstances, considering such issues as design preference, user preferences, marketing preferences, cost, structural requirements, available materials, technological advances, etc., other methods of use arrangements such as, for example, different orders within above-mentioned list, elimination or addition of certain steps, including or excluding certain maintenance steps, etc., may be sufficient.
The embodiments of the invention described herein are exemplary and numerous modifications, variations and rearrangements can be readily envisioned to achieve substantially equivalent results, all of which are intended to be embraced within the spirit and scope of the invention. Further, the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, and especially the scientist, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application.