System and method for automatically controlling and measuring oxygen concentration for combustion conditions

Abstract

A system may include a gas mixing device configured to generate a gas mixture and fill a gas reservoir with the gas mixture; a constant volume combustion chamber configured to receive the gas mixture from the gas mixing device; carrying out a combustion test on the test sample by using the received gas mixture; and a controller. The controller may be configured to select a target oxygen concentration of the gas mixture; measuring the concentration of oxygen received by the gas mixing device in the inlet air gas source; controlling nitrogen flow and intake air gas flow from an intake air gas source to fill the gas reservoir with a gas mixture having a selected target oxygen concentration; and outputting the gas mixture from the filled gas reservoir for a combustion test.

Description

Background Art

[0001] Hydrocarbon products, such as petroleum and biomass, are used as a fuel source for internal combustion engines. Different types of hydrocarbon fuels have different compositions, and these different compositions exhibit different combustion characteristics. Therefore, the different compositions may affect the performance of the hydrocarbon fuel. Combustion tests may be performed on hydrocarbon fuel samples to determine various properties of the samples. In order for the combustion test to produce accurate results, it may be necessary to precisely control the conditions under which the combustion test is conducted. Controlling the combustion conditions for a combustion test may present various difficulties. BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Figure 1 shows a constant volume combustion chamber system according to the embodiments described herein;

[0003] Figure 2 shows exemplary components of a gas mixing system according to embodiments described herein;

[0004] Figure 3 shows an exemplary layout of a gas mixing system according to embodiments described herein;

[0005] Figure 4 shows exemplary components of a controller unit and / or other components of a constant volume combustor system according to embodiments described herein;

[0006] Figure 5 shows exemplary functional components of a controller unit according to embodiments described herein;

[0007] Figure 6 is a flow chart of a first process for generating and using a gas mixture for conducting a combustion test according to embodiments described herein;

[0008] Figure 7 is a flow chart of a second process for generating and using a gas mixture for conducting a combustion test according to embodiments described herein;

[0009] Figure 8 shows an exemplary gas flow for calibrating an oxygen sensor using nitrogen according to embodiments described herein;

[0010] Fig. 9 shows an exemplary gas flow for calibrating an oxygen sensor using oxygen according to embodiments described herein;

[0011] Fig.10 shows an exemplary gas flow for measuring oxygen concentration of an incoming air gas according to embodiments described herein;

[0012] Fig.11shows an exemplary gas flow for producing a gas mixture having a particular oxygen concentration according to embodiments described herein; and

[0013] Fig.12 An exemplary gas flow for measuring the oxygen concentration of a produced gas mixture is shown according to embodiments described herein. DETAILED DESCRIPTION

[0014] The following detailed description refers to the accompanying drawings. The same reference numbers in different drawings indicate the same or similar elements.

[0015] Research Octane Number (RON) and Motor Octane Number (MON) are numerical ratings of the knock resistance of spark-ignition engine fuels. Knock resistance refers to the ability of a fuel not to self-ignite and not to burn in an uncontrolled manner during compression. For example, the RON and MON of a fuel can be determined by burning the fuel in a test engine under controlled conditions and comparing the results with those obtained from a reference mixture of isooctane and n-heptane, referred to as a primary reference fuel (PRF) mixture. RON can be measured at lower engine speeds (e.g., 600 rpm, etc.), lower temperatures (e.g., without preheating the fuel mixture, etc.), and / or without using variable ignition timing. MON can be measured at higher engine speeds (e.g., 900 revolutions per minute (rpm), etc.), higher temperatures (e.g., with a preheated fuel mixture, etc.), and / or by using variable ignition timing. Another parameter that can be measured in a combustion test can be the cetane number (CN) of a diesel fuel sample, which corresponds to a measure of the combustion velocity and compression required for ignition of the diesel fuel sample.

[0016] Combustion tests can be carried out in standardized single-cylinder Cooperative Fuel Research (CFR) engines to determine RON, MON and / or CN. There are many disadvantages to using such engines for combustion tests, such as the large amount of fuel required for each test, a trained operator and the large space used for the engine itself. In addition, the high complexity of the test method using CFR engines means that the repeatability and reproducibility of the measurements are limited, resulting in high costs for the preparation of standardized fuels.

[0017] Instead of using a single-cylinder CFR engine, a combustion test can be performed using a constant volume combustion chamber. A constant volume combustion chamber can use pressure and temperature to produce an autoignition event to measure RON, MON, CN, and / or other fuel sample combustion parameters. For example, a constant volume combustion chamber can be used to obtain pressure and time data, which can be used to estimate the RON, MON, and / or CN of a fuel sample.

[0018] Combustion tests can be conducted using ambient air to provide the oxygen required for combustion. However, the amount of oxygen molecules in the air may vary depending on the altitude and atmospheric pressure of the ambient air. In addition, the ambient air may include other gases, impurities and / or contaminants (e.g., water vapor, volatile hydrocarbons and / or dust particles) that may affect the results of the combustion test. In particular, changes in oxygen concentration may have a significant impact on combustion measurements (e.g., RON, MON and / or CN). One way to improve the accuracy of combustion tests may be to use synthetic air, which is a mixture of pure nitrogen and pure oxygen in fixed proportions. However, synthetic air can be expensive to produce and may not provide high accuracy because the actual oxygen concentration may vary between different synthetic air tanks.

[0019] Embodiments described herein relate to systems and methods for automatically controlling and measuring oxygen concentration for combustion test conditions. A gas mixing system can produce, store, and use a gas mixture having a selected oxygen concentration. An oxygen sensor can measure the oxygen concentration of an incoming air gas, and the incoming air gas can be mixed with an inert gas (e.g., nitrogen) to produce a gas mixture having a selected oxygen concentration. The incoming air gas can include zero-grade air stored in a gas storage container, from which water vapor, carbon dioxide, methane, and / or other impurities have been removed. For example, a zero-grade air generator can be used to produce the incoming air gas.

[0020] The gas mixture produced can be stored in a gas reservoir for use in a combustion test and can be delivered to a constant volume combustion chamber during the combustion test. The gas mixing system can also measure the oxygen concentration of the gas mixture produced to confirm that the oxygen concentration of the gas mixture is within a specified tolerance of a selected oxygen concentration. In addition, the gas mixing system can automatically calibrate the oxygen sensor using nitrogen and oxygen to ensure that there is no drift or change during the gas mixing process. Therefore, the gas mixing system is able to continuously produce a gas mixture with a selected oxygen concentration using incoming air gas and / or ambient air, resulting in accurate and consistent combustion tests to determine parameters such as RON, MON, CN and / or other types of fuel sample combustion parameters.

[0021] The gas mixing system may include: a first gas conduit for receiving nitrogen from a nitrogen source; a second gas conduit for receiving incoming air gas from an incoming air gas source; a third gas conduit for receiving oxygen from an oxygen source; a gas reservoir coupled to the first gas conduit and the second gas conduit; a gas mixing manifold coupled to the gas reservoir, the first gas conduit, and the second gas conduit; an oxygen sensor coupled to the gas mixing manifold and the third gas conduit; and a controller.

[0022] The controller can be configured to select a target oxygen concentration for a gas mixture for a combustion test; measure the oxygen concentration in the incoming air gas received via the second gas conduit using an oxygen sensor; control the nitrogen flow rate in the first gas conduit and the incoming air gas flow rate in the second gas conduit based on the measured oxygen concentration in the incoming air gas to fill the gas reservoir with the gas mixture having the selected target oxygen concentration; and control the discharge of the gas mixture from the filled gas reservoir for the combustion test.

[0023] The controller may also be configured to measure the oxygen concentration of the gas mixture in the filled gas reservoir using the oxygen sensor to confirm that the gas mixture in the filled gas reservoir has a selected target oxygen concentration.

[0024] The gas mixing system may further include a valve for selecting between oxygen from the third gas conduit and gas from the gas mixing manifold; and the controller may further be configured to calibrate the oxygen sensor using nitrogen from the first gas conduit via the gas mixing manifold to calibrate the oxygen sensor using gas having an oxygen concentration of zero, and to calibrate the oxygen sensor using oxygen from the third gas conduit to calibrate the oxygen sensor using an oxygen concentration gas source having a guaranteed oxygen concentration (e.g., 99.994% oxygen, etc.).

[0025] In some embodiments, the gas mixing system may include a connection from the third gas conduit to the gas reservoir to enable production of synthetic air, and the controller may be further configured to control the nitrogen flow in the first gas conduit and the oxygen flow in the third gas conduit to fill the gas reservoir with a synthetic air gas mixture having a selected target oxygen concentration.

[0026] The gas mixing system may also include: a first mass flow controller, which is used to control the flow of nitrogen in the first gas conduit; a second mass flow controller, which is used to control the flow of incoming air gas in the second gas conduit; and a back pressure regulator, which is connected from the first mass flow controller and the second mass flow controller to the gas reservoir.

[0027] The gas mixing system may further include a discharge valve connected to the oxygen sensor and configured to discharge gas from a conduit connected to the oxygen sensor to speed up the oxygen measurement process. The gas mixing system may further include a pressure regulator connected to the gas reservoir, the pressure regulator being configured to control an outlet pressure of the gas reservoir.

[0028] Figure 1 FIG. 1 shows a constant volume combustion chamber system 100 according to an embodiment described herein. Figure 1As shown, the constant volume combustion chamber system 100 may include a constant volume combustion chamber 110, a sample injector 130, a sample container 132, a pump 133, a sample conduit 134, a gas mixing system 140, a gas cylinder 142, a gas conduit 144, a cooling system 160, a cooling system conduit 162, a heating controller 170, a controller unit 180 and a power supply 190.

[0029] The constant volume combustion chamber 110 may include a chamber interior 112 , an inner wall 114 , an outer wall 116 , a heating element 118 , an exhaust port 120 , a sample injector nozzle 136 , an injector cooling jacket 138 , a gas conduit nozzle 146 , a temperature sensor 172 , a pressure sensor 182 , and a pressure sensor cooling jacket 184 .

[0030] The inner wall 114 may enclose the chamber interior 112, and the outer wall 116 may protect the inner wall 114 and the chamber interior 112 and isolate them from the external environment. The inner wall 114 and the outer wall 116 may enclose a heating element 118. The heating element 118 may include a resistive heating element and / or another type of heating element to enable the heating controller 170 to increase the temperature of the chamber interior 112 to a specific temperature. The exhaust port 120 may exhaust gas from the chamber interior 112 after the combustion test is completed.

[0031] The sample injector nozzle 136 may connect the sample conduit 134 to the chamber interior 112 and inject the sample into the chamber interior 112 to perform a combustion test. The injector cooling jacket 138 may thermally insulate the sample injector nozzle 136 from the inner wall 114 to ensure that the sample injected into the chamber interior 112 does not heat up prematurely and to protect the sample injector 130 and the sample injector nozzle 136 from high temperatures. The gas conduit nozzle 146 may connect the gas conduit 144 to the chamber interior 112 and inject the gas mixture into the chamber interior 112 to perform a combustion test.

[0032] The gas mixing system 140 can mix the gases from the gas cylinders 142 to produce a specific gas mixture (e.g., a gas mixture with a specified oxygen percentage) based on instructions received from the controller unit 180. The gas mixing system 140 can store the produced gas mixture in a gas reservoir and deliver the stored gas mixture to the chamber interior 112 via the gas conduit 144 during the combustion test. The gas cylinders 142 may include oxygen (O2) cylinders, nitrogen (N2) cylinders, and exhaust air cylinders. Alternatively, ambient air may be used as an air source. In some embodiments, the gas mixing system 140 may include a controller 145. The controller 145 may control the operation of the gas mixing system 140. The controller 145 may use a wired and / or wireless connection (e.g., connect, The gas mixing system 140 may include an oxygen sensor 150. The oxygen sensor 150 may measure the oxygen content of the gas in the gas mixing system 140 (e.g., the incoming air, the ambient air, the generated gas mixture, etc.). Figure 2 Exemplary components of gas mixing system 40 are described.

[0033] The temperature sensor 172 may include a thermocouple, a resistance temperature sensor, a thermistor temperature sensor, a semiconductor temperature sensor, and / or another type of temperature sensor. The temperature sensor 172 may measure the temperature of the chamber interior 112 and provide the measured temperature to the controller unit 180 and / or the heating controller 170.

[0034] The pressure sensor 182 can measure the pressure in the chamber interior 112 during the combustion test. The pressure sensor 182 can include a differential pressure sensor, such as a diaphragm with a piezoresistive, piezoelectric, and / or capacitive strain gauge. In other embodiments, the pressure sensor 182 can include another type of pressure sensor, such as an absolute pressure sensor. The pressure sensor cooling jacket 184 can thermally insulate the pressure sensor 182 from the inner wall 114 to ensure that the measurement performed by the pressure sensor 182 is not affected by the high temperature of the inner wall 114.

[0035] The sample injector 130 may include a pressure injection system for injecting a fuel sample from a sample container 132 into the chamber interior 112 via a sample conduit 134 and a sample injector nozzle 136. A pump 133 may pressurize the sample from the sample container 132 and pump the sample to the sample injector 130. The cooling system 160 may pump water and / or a cooling fluid through a cooling system conduit 162. The cooling system conduit 162 may direct water and / or a cooling fluid to cool the sample injector nozzle 136 and / or the pressure sensor 182 during a combustion test. In some embodiments, the pressure sensor 182 may include an integrated cooling conduit that may be coupled to the cooling system conduit 162 to cool the pressure sensor 182 during a combustion test.

[0036] The heating controller 170 may be coupled to the heating element 118 to provide power to the heating element 118 to raise the temperature of the chamber interior 112 to a specific temperature during a combustion test. The heating controller 170 may receive information from the temperature sensor 172 to adjust the heating element 118 to maintain a specific temperature in the chamber interior 112.

[0037] The controller unit 180 may include a processor, microcontroller, and / or computer device that controls the operation of the constant volume combustor system 100 (which includes the gas mixing system 140). Figure 4 and Figure 5 1 and 2 illustrate exemplary components of the controller unit 180. The power supply 190 may provide power to the controller unit 180 and to the sample injector 130, the gas mixing system 140, the oxygen sensor 150, the cooling system 160, the heating controller 170, and / or the pressure sensor 182 ( Figure 1 In other embodiments, the gas mixing system 140 may include a separate controller ( Figure 1 not shown).

[0038] although Figure 1 1 shows exemplary components of the constant volume combustor system 100, but in other embodiments, the constant volume combustor system 100 may include Figure 1 Fewer components, different components, components arranged in a different manner, or additional components are shown. Additionally, or alternatively, one or more components of constant volume combustor system 100 may perform functions described as being performed by one or more other components of constant volume combustor system 100.

[0039] Figure 2 Exemplary components of the gas mixing system 140 are shown. Figure 2As shown, the gas mixing system 140 may include a housing 205, an oxygen source 210, an oxygen regulator 211, an oxygen conduit 212, a filter 214, a safety pressure relief valve 216, a pressure sensor 218, a nitrogen source 220, a nitrogen regulator 221, a nitrogen conduit 222, a filter 224, a safety pressure relief valve 226, a pressure sensor 228, a second nitrogen conduit 229, an incoming air gas source 230, an incoming air gas regulator 231, an incoming air gas conduit 232, a filter 234, a pressure relief valve 236, a pressure sensor 238, a second incoming air gas conduit 239, a gas selection valve 240, 24, a flow control valve 244, an oxygen sensor 150, a pressure sensor 250, a measured gas outlet 252, a check valve 254, a gas mixing manifold 260, a gas mixing manifold conduit 261, a regulator 262, a check valve 264, a mass flow controller (MFC) 266, a T-type interconnect 267, a back pressure regulator 268, a gas reservoir inlet conduit 269, a gas reservoir 270, a gas reservoir outlet conduit 271, a pressure sensor 272, a pressure sensor 273, a regulator 274, a pressure gauge 275, a check valve 276, a mass flow controller 278, and a gas reservoir outlet 280. The controller 145 may be connected to some or all of the sensors and actuators of the gas mixing system 140 via wired and / or wireless connections. For purposes of illustration, Figure 2 The controller 145 and the connections between the controller 145 and the sensors and actuators of the gas mixing system 140 are not shown.

[0040] The housing 205 can enclose and contain the components of the gas mixing system 140 and protect the components of the gas mixing system 140 from the environment. In some embodiments, the housing 205 can include a metal, plastic, wooden and / or composite material container that completely or partially encloses the components of the gas mixing system 205 and protects the components of the gas mixing system 140 from dust and / or other contaminants. In addition, in some embodiments, the housing 205 can be water-resistant, waterproof and / or heat-insulated. The oxygen conduit 212, the nitrogen conduit 222, the incoming air gas conduit 232, the exhaust valve 242, the measured gas outlet 252 and / or the gas reservoir outlet 280 can be mounted to the wall of the housing 205 using a bulkhead. In other embodiments, the housing 205 can include a partially open or fully open structural chassis, such as a rectangular chassis with or without diagonal support beams. The chassis may include metal and / or plastic structural tubing having a rectangular, H-profile, C-profile, and / or L-profile cross-section; solid bar beams; and / or other types of beams.

[0041] The oxygen source 210 may include a gas tank, gas bottle and / or oxygen cylinder with a guaranteed oxygen concentration (e.g., 99.994% oxygen, etc.). The oxygen regulator 211 may control the pressure of the oxygen from the oxygen source 210. For example, the oxygen regulator 211 may be set to 2.8 bar. The oxygen conduit 212 may include a gas conduit from the oxygen source 210 to the gas selection valve 240. The oxygen conduit 212 may include, for example, a polytetrafluoroethylene (PFE) tube with a diameter of 1 / 8 inch. In some embodiments, the oxygen conduit 212 may include a mass flow controller and a connection to the gas reservoir 270 ( Figure 2 210 ) to produce a synthetic air gas mixture and / or to produce a gas mixture having an oxygen concentration higher than the oxygen concentration entering the air gas source 230. The filter 214 can filter out particulate matter in the oxygen source 210. For example, the filter 214 can include a two-micron filter. The safety relief valve 216 can be configured to release the pressure in the oxygen conduit 212 when the pressure rises above a threshold. For example, the safety relief valve 216 can be set to 3.5 bar and can be opened when the pressure reaches 3.5 bar. The pressure sensor 218 can monitor the pressure in the oxygen conduit 212.

[0042] The nitrogen source 220 may include a gas tank, a gas bottle and / or a nitrogen cylinder with a guaranteed nitrogen concentration (e.g., 99.999% nitrogen, etc.). In other embodiments, different inert gases (e.g., argon, etc.) may be used. The nitrogen regulator 221 may control the pressure of the nitrogen from the nitrogen source 220. For example, the nitrogen regulator 221 may be set to 40 bar. The nitrogen conduit 222 may include a gas conduit from the nitrogen source 220 to the T-type interconnect 267. The nitrogen conduit 222 may include, for example, a polyamide (PA) tube having a diameter of 1 / 4 inch. The second nitrogen conduit 229 may connect the nitrogen source 220 to the gas mixing manifold 260. The second nitrogen conduit 229 may include, for example, a PA tube having a diameter of 1 / 8 inch. The filter 224 may filter out particulate matter from the nitrogen source 220. For example, the filter 224 may include a two-micron filter that filters particles having a diameter greater than two microns. The safety relief valve 226 may be configured to release the pressure in the nitrogen conduit 222 if the pressure rises above a threshold. For example, the safety relief valve 226 may be set to 44 bar and may open when the pressure reaches 44 bar. The pressure sensor 228 may monitor the pressure in the nitrogen conduit 222.

[0043] The inlet air gas source 230 may include a gas tank, a gas bottle, and / or a zero-grade air cartridge. In other embodiments, compressed air may be used as the inlet air gas source. Additionally, in some embodiments, the gas mixing system 140 may include a gas selection valve ( Figure 22 (not shown) to select between a zero-grade air source and compressed air. The inlet air gas regulator 231 can control the pressure of the inlet air gas from the inlet air gas source 230. For example, the inlet air gas regulator 231 can be set to 40 bar. The inlet air gas conduit 232 can include a gas conduit from the inlet air gas source 230 to the T-type interconnect 267. The inlet air gas conduit 232 can include, for example, a PA tube with a diameter of 1 / 4 inch. The second inlet air gas conduit 239 can connect the inlet air gas source 230 to the gas mixing manifold 260. The second inlet air gas conduit 239 can include, for example, a PA tube with a diameter of 1 / 8 inch. The filter 234 can filter out particulate matter from the inlet air gas source 230. For example, the filter 234 can include a two-micron filter. The safety relief valve 236 can be configured to release the pressure in the inlet air gas conduit 232 when the pressure rises above a threshold. For example, the safety relief valve 236 can be set to 44 bar. A pressure sensor 238 may monitor the pressure within the incoming air gas conduit 232 .

[0044] The gas selection valve 240 may include a solenoid-activated self-returning valve configured to select a gas flow between the oxygen in the oxygen conduit 212 and the gas from the gas mixing manifold conduit 261. The exhaust valve 242 may include a solenoid-activated self-returning valve, the function of which is to exhaust the gas from the conduit to the oxygen sensor 150. The exhaust valve 242 may accelerate the oxygen concentration measurement in the gas mixing system 140. The flow control valve 244 may reduce the diameter of the gas conduit input to the oxygen sensor 150 to 75 microns. The oxygen sensor 150 may include an oxygen sensor module 246, a temperature sensor 248, and a heater 249. The oxygen sensor module 246 may be calibrated at a specific temperature (e.g., at 55° C., etc.). The temperature sensor 248 may measure the temperature of the oxygen sensor module 246, and the controller 145 may use the heater 249 and the temperature measurement performed by the temperature sensor 248 to maintain the oxygen sensor module 248 at a specific temperature.

[0045] The pressure sensor 250 can measure the pressure in the measured gas outlet conduit. The measured gas outlet 252 can allow the gas being measured by the oxygen sensor 150 to exit so that the gas can flow through the oxygen sensor 150. The measured pressure in the gas outlet conduit can be used to pressure compensate the oxygen concentration measured by the oxygen sensor 150. The oxygen sensor 150 can be calibrated at a calibration pressure, and the oxygen concentration measured by the oxygen sensor 150 can be adjusted based on the ratio of the calibration pressure to the pressure measured by the pressure sensor 250. The adjusted oxygen concentration can be calculated using the following equation: A =O M *(P C / PM ), where O A Corresponding to the adjusted oxygen concentration, O M Corresponding to the measured oxygen concentration, P C corresponds to the calibration pressure, and P M Corresponds to the pressure measured by pressure sensor 250 .

[0046] The check valve 254 may include a spring return check valve to prevent the backflow of gas in the gas reservoir outlet conduit 271. The gas mixing manifold 260 may include a first inlet from the second nitrogen conduit 229, a second inlet from the second inlet air gas conduit 239, a third inlet from the gas reservoir outlet conduit 271, and an outlet to the gas mixing manifold conduit 261. Each inlet of the gas mixing manifold 260 may include a solenoid-activated self-return valve. The gas mixing manifold 260 is operated by the controller 145 (e.g., alone or together with the controller unit 180, etc.) to enable the gas from the first inlet, the second inlet, or the third inlet to pass to the outlet gas mixing manifold conduit 261. Therefore, the gas mixing manifold 260 is capable of selecting the outlet gas, and the nitrogen from the nitrogen source 220, the inlet air gas from the inlet air gas source 230, or the stored gas mixture from the gas reservoir 270 is used as the inlet air gas entering the oxygen sensor 150 to measure the oxygen concentration of the outlet gas from the gas mixing manifold 260. The regulator 262 may include a needle valve and a pressure gauge configured to maintain a specific pressure in the gas mixing manifold conduit 261. For example, the regulator 262 may be set to 2.9 bar.

[0047] The check valve 264 may include a spring return check valve to prevent the backflow of the gas in the nitrogen conduit 222. The mass flow controller 266 may control the flow of the gas in the nitrogen conduit 222. The check valve 276 may include a spring return check valve to prevent the backflow of the gas in the air gas conduit 232. The mass flow controller 278 may control the flow of the gas in the air gas conduit 232. The T-type interconnect 267 may interconnect the nitrogen conduit 222 and the air gas conduit 232 with the gas reservoir inlet conduit 269. The back pressure regulator 268 may maintain a specific pressure in the gas reservoir inlet conduit 269 based on the pressure measured by the pressure sensor 273. For example, the back pressure regulator 268 may be set to a specific pressure (e.g., 28 bar, etc.) to maintain an optimal pressure difference between the inlet and outlet of the MFC 266 and the MFC 278, thereby maintaining appropriate flow control. The gas reservoir inlet conduit 269 may connect the T-type interconnect 267 to the inlet of the gas reservoir 270.

[0048] The gas reservoir 270 may include a reservoir for storing a gas mixture produced by mixing nitrogen from the nitrogen source 220 and the intake air gas from the intake air gas source 230. In some embodiments, the gas reservoir inlet conduit 269 may also include a connection from the oxygen conduit 212 to enable the production of a synthetic air gas mixture. The gas reservoir 270 may include, for example, a one-liter gas reservoir. The gas reservoir outlet conduit 271 may interconnect the gas reservoir 270 with the inlet of the gas mixing manifold 260 to enable the measurement of the oxygen concentration of the gas mixture stored in the gas reservoir 270. The pressure sensor 272 may measure the pressure in the gas reservoir 270 in order to monitor the amount of mixed gas in the gas reservoir 270. The regulator 274 may maintain a specific pressure in the gas reservoir outlet 280 based on the pressure measured by the pressure gauge 275. For example, the regulator 274 may be set to 25 bar to ensure that the gas delivered to the chamber interior 112 during the combustion test is delivered at a pressure of 25 bar. During a combustion test, the gas reservoir outlet 280 can provide gas from the gas reservoir 270 to the chamber interior 112. Although the gas reservoir outlet 280 is shown as being connected to the gas reservoir inlet conduit 269 via a T-type interconnect, in other embodiments, the gas reservoir outlet 280 can be connected to the gas reservoir outlet conduit 271 via a T-type interconnect.

[0049] Figure 3 An exemplary layout of the gas mixing system 140 is shown. As described above, in some embodiments, the components of the gas mixing system 140 can be mounted on an open chassis. In other embodiments, the components of the gas mixing system 140 can be mounted in a closed housing, and the gas inlets and outlets (e.g., oxygen conduit 212, nitrogen conduit 222, incoming air gas conduit 232, exhaust valve 242, measured gas outlet 252, and / or gas reservoir outlet 280) can be mounted on the wall of the housing using baffles. For illustrative purposes, Figure 3 The open chassis and / or housing are not shown.

[0050] although Figure 2 and Figure 3 1 shows exemplary components of the gas mixing system 140, but in other embodiments, the gas mixing system 40 may include more Figure 2 or Figure 3 Fewer components, different components, components arranged in a different manner, or additional components may be shown. Additionally, or alternatively, one or more components of gas mixing system 140 may perform functions described as being performed by one or more other components of gas mixing system 40 .

[0051] Figure 4400 according to embodiments described herein. The sample injector 130, the gas mixing system 140, the cooling system 160, the heating controller 170, and / or the controller unit 180 may each include one or more of the apparatus 400. Figure 4 As shown, device 400 may include a bus 410 , a processor 420 , a memory 430 , an input device 440 , an output device 450 , and a communication interface 460 .

[0052] The bus 410 may include a path that allows communication between components of the device 400. The processor 420 may include any type of single-core processor, multi-core processor, microprocessor, latch-based processor, and / or processing logic (or series of processors, microprocessors, and / or processing logic) that interprets and executes instructions. In other embodiments, the processor 420 may include an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), and / or another type of integrated circuit or processing logic.

[0053] The memory 430 may include any type of dynamic storage device that can store information and / or instructions for execution by the processor 420 and / or any type of non-volatile storage device that can store information for use by the processor 420. For example, the memory 430 may include a random access memory (RAM) or another type of dynamic storage device, a read-only memory (ROM) device or another type of static storage device, a content addressable memory (CAM), a magnetic and / or optical recording storage device and its corresponding drive (e.g., a hard disk drive, an optical disk drive, etc.), and / or a removable form of memory (e.g., flash memory).

[0054] Input device 440 may allow an operator to input information into device 400. Input device 440 may include, for example, a keyboard, a mouse, a pen, a microphone, a remote control, an audio capture device, an image and / or video capture device, a touch screen display, and / or another type of input device. In some embodiments, device 400 may be remotely managed and may not include input device 440. In other words, for example, device 400 may be "headless" and may not include a keyboard.

[0055] Output device 450 may output information to an operator of device 400. Output device 450 may include a display, a printer, a speaker, and / or another type of output device. For example, device 400 may include a display, which may include a liquid crystal display (LCD), a light emitting diode (LED) display, etc., for displaying content to an operator. In some embodiments, device 400 may be remotely managed and may not include output device 450. In other words, for example, device 400 may be "headless" and may not include a display.

[0056] The communication interface 460 may include a transceiver that enables the device 400 to communicate with other devices and / or systems via wireless communication (e.g., radio frequency, infrared, and / or visual optics, etc.), wired communication (e.g., wires, twisted pairs, coaxial cables, transmission lines, fiber optic cables, and / or waveguides, etc.), or a combination of wireless and wired communication. The communication interface 460 may include a transmitter that converts a baseband signal to a radio frequency (RF) signal and / or a receiver that converts an RF signal to a baseband signal. The communication interface 460 may be coupled to an antenna for sending and receiving RF signals.

[0057] The communication interface 460 may include logic components including input and / or output ports, input and / or output systems, and / or other input and output components that facilitate the transfer of data to other devices. For example, the communication interface 460 may include a network interface card (e.g., an Ethernet card) for wired communication and / or a wireless network interface (e.g., WiFi) card for wireless communication. The communication interface 460 may also include a universal serial bus (USB) port, a Bluetooth port, or a wireless network interface (e.g., a Wi-Fi port) for communication via a cable. TM A wireless interface, a radio frequency identification (RFID) interface, a near field communication (NFC) wireless interface, and / or any other type of interface that converts data from one form to another.

[0058] As will be described in detail below, the device 400 can perform certain operations related to the generation, storage and / or use of a gas mixture with a specified oxygen concentration for a combustion test. The device 400 can perform these operations in response to the processor 420 executing software instructions contained in a computer-readable medium (e.g., memory 430). A computer-readable medium can be defined as a non-transient storage device. The storage device can be implemented in a single physical storage device or can be spread over multiple physical storage devices. The software instructions can be read from another computer-readable medium or from another device into the memory 430. The software instructions contained in the memory 430 can cause the processor 420 to perform the process described herein. As an alternative, a hard-wired circuit can be used in place of the software instructions or in combination with the software instructions to implement the process described herein. Therefore, the embodiments described herein are not limited to any specific combination of hardware circuits and software.

[0059] although Figure 4 Exemplary components of device 400 are shown, but in other embodiments, device 400 may include Figure 4 Fewer components, different components, additional components, or components arranged in a different manner may be shown in the device 400. Additionally or alternatively, one or more components of the device 400 may perform one or more tasks described as being performed by one or more other components of the device 400.

[0060] Figure 5 Exemplary functional components of controller unit 180 and / or controller 145 are shown. In some embodiments, Figure 5 The functional components of may be implemented in the controller unit 180. In other embodiments, Figure 5 One or more functional components of may be implemented in the controller 145, and Figure 5 Other functional components of the controller unit 180 may be implemented in the controller unit 180. The functional components of the controller unit 180 and / or the controller 145 may be implemented, for example, via the processor 420 executing instructions from the memory 430. Figure 5 As shown, the controller unit 180 and / or the controller 145 may include a chamber controller 510 , a gas mixing system controller 520 , a combustion test manager 530 , an analyzer 540 , and a user interface 550 .

[0061] The chamber controller 510 may control the operation of the constant volume combustion chamber system 100 based on the information received from the combustion test manager 530. The chamber controller 510 may include a heating controller interface 512, a gas mixing system interface 514, a sample injector interface 516, and a cooling system interface 518. The heating controller interface 512 may be configured to interface with the heating controller 170. For example, the heating controller interface 512 may instruct the heating controller 170 to maintain a specific temperature during the combustion test. The gas mixing system interface 514 may be configured to interface with the gas mixing system controller 520. For example, the gas mixing system interface 514 may instruct the gas mixing system controller 520 to generate a specific gas mixture (e.g., a gas mixture with a specific oxygen percentage) for the combustion test and / or to generate a specific pressure within the chamber interior 112 for the combustion test. The sample injector interface 516 may be configured to interface with the sample injector 130. For example, the sample injector interface 516 may instruct the sample injector 130 to inject a sample for a specific duration during the combustion test. The cooling system interface 518 may be configured to interface with the cooling system 160. For example, the cooling system interface 518 may instruct the cooling system 160 to begin circulating water and / or cooling fluid before, during, and / or after a combustion test.

[0062] The gas mixing system controller 520 can control the operation of the gas mixing system 140. In some embodiments, the gas mixing system controller 520 can be included in the controller unit 180. In other embodiments, the gas mixing system controller 520 can be included in the controller 145. The gas mixing system controller 520 can include a calibration manager 522, an incoming air gas monitor 524, a gas reservoir manager 526, and a gas reservoir monitor 528.

[0063] The calibration manager 522 may calibrate the oxygen sensor 150 at specific time intervals. For example, the calibration manager 522 may calibrate the oxygen sensor 150 before each combustion test. The calibration manager 522 may calibrate the oxygen sensor 150 using nitrogen from the nitrogen source 220 to obtain a gas with a zero oxygen concentration or a guaranteed or predetermined maximum oxygen concentration of the nitrogen source 220. The calibration manager 522 may calibrate the oxygen sensor 150 using oxygen from the oxygen source 210, wherein the oxygen concentration gas source has a guaranteed minimum oxygen concentration (e.g., 99.994% oxygen, etc.).

[0064] The intake air gas monitor 524 may monitor the oxygen concentration in the intake air gas from the intake air gas source 230 and / or the ambient air. For example, the intake air gas monitor 524 may use the gas mixing manifold 260 to select the gas from the second intake air gas conduit 239 as the outlet gas in the gas mixing manifold conduit 261, and may control the gas selection valve 240 to select the gas from the gas mixing manifold conduit 261 as the inlet gas for the oxygen sensor 150.

[0065] The gas reservoir manager 526 can manage the gas mixture in the gas reservoir 270. For example, the gas reservoir manager 526 can control the mass flow controllers 266 and 278 and the back pressure regulator 268 to fill the gas reservoir 270 with a gas mixture having a selected oxygen concentration (e.g., 20% oxygen, etc.) and a selected pressure (e.g., 35 bar, etc.). In addition, the gas reservoir manager 526 can control the outflow of gas from the gas reservoir 270 to the chamber interior 112 via the gas reservoir outlet 280 at a specific pressure (e.g., 25 bar, etc.).

[0066] The gas reservoir monitor 528 can monitor the oxygen concentration in the gas mixture in the gas reservoir 270. For example, the gas reservoir monitor 528 can use the gas mixing manifold 260 to select the gas from the gas reservoir outlet conduit 271 as the outlet gas in the gas mixing manifold conduit 261, and can control the gas selection valve 240 to select the gas from the gas mixing manifold conduit 261 as the inlet gas for the oxygen sensor 150.

[0067] The combustion test manager 530 may manage the combustion test performed by the constant volume combustor system 100. For example, the combustion test manager 530 may obtain a combustion test setting value from a stored set of combustion test setting values, perform the combustion test according to the obtained combustion test setting value, receive pressure and time data of the combustion test, and store the received pressure and time data in a database.

[0068] The analyzer 540 may use the determined pressure parameter values ​​for the samples of known combustion parameters to generate a combustion parameter function for a set of combustion test conditions. The analyzer 540 may correlate a set of pressure parameter values ​​for the samples with the known or previously determined parameter values ​​for the samples to generate a parameter function using regression analysis and / or a machine learning model.

[0069] The user interface 550 may be configured to interface with the input device 440 and / or the output device 450. The user interface 550 may include an interface that enables a user to control the constant volume combustor system 100 and / or receive information generated by the controller unit 180 (e.g., a generated pressure versus time graph, a graph of a specific pressure parameter derived from the pressure versus time data, a generated parameter function, a calculated parameter of a sample, a message about a combustion test that has been completed or is in progress) and / or other types of information that may be input by a user or may be output for a user. In addition, the user interface 550 may be used to control and / or configure the gas mixing system 140. For example, the user interface 550 may be used to instruct the gas mixing system controller 520 to select an oxygen concentration for the gas mixture, calibrate the oxygen sensor 150, measure the oxygen concentration of the incoming air gas source, measure the oxygen concentration of the gas mixture in the gas reservoir 270, set a pressure threshold for a specific regulator in the gas mixing system 140, and / or perform another function or configuration associated with the gas mixing system 140.

[0070] although Figure 5 Exemplary components of controller unit 180 and / or controller 145 are shown, but in other embodiments, controller unit 180 and / or controller 145 may include more Figure 5 Fewer components, different components, additional components, or components arranged in a different manner are shown. In addition, or as an alternative, one or more components of the controller unit 180 and / or the controller 145 can perform one or more tasks described as being performed by one or more other components of the controller 145 and / or the controller unit 180.

[0071] Figure 6 is a flow chart of a first process 600 for generating and using a gas mixture for a combustion test according to embodiments described herein. In some embodiments, Figure 6 The process may be performed by and / or using the constant volume combustion chamber system 100. In other embodiments, Figure 6 Some or all of the processes may be performed by or using another device or a group of devices separate from the constant volume combustor system 100.

[0072] The process 600 may include calibrating the oxygen sensor (block 610). For example, the controller unit 180 and / or the controller 145 may control the gas mixing system 140 to measure the oxygen concentration of the nitrogen source 220 using the oxygen sensor 150, and then adjust the measured oxygen concentration to the known oxygen concentration of the nitrogen source 220. The known oxygen concentration of the nitrogen source 220 may be based on a guaranteed or predetermined maximum oxygen concentration of the nitrogen source 220. The controller unit 180 and / or the controller 145 may then control the gas mixing system 140 to measure the oxygen concentration of the oxygen source 210 using the oxygen sensor 150, and then adjust the measured oxygen concentration to the known oxygen concentration of the oxygen source 210. The known oxygen concentration of the oxygen source 210 may be based on a guaranteed or predetermined minimum oxygen concentration of the oxygen source 210. Alternatively, the oxygen concentration of the oxygen source 210 may be measured during calibration, and then the oxygen concentration of the nitrogen source 220 may be measured.

[0073] Process 600 may also include selecting a target oxygen concentration for a gas mixture for a combustion test (box 620), measuring the oxygen concentration of the incoming air gas (box 630), selecting a gas mixture for the combustion test based on the selected target oxygen concentration and the measured oxygen concentration of the incoming air gas (box 640), and filling a gas reservoir with the selected gas mixture (box 650).

[0074] For example, the operator may select an oxygen concentration (e.g., 20% oxygen, etc.) for the combustion test. The controller unit 180 and / or the controller 145 may control the gas mixing system 140 to measure the oxygen concentration of the incoming air gas source 230 (and / or the oxygen concentration of the ambient air) using the oxygen sensor 150. The controller unit 180 and / or the controller 145 may then determine how to produce a gas mixture having a selected oxygen concentration based on the determined oxygen concentration of the incoming air gas (and / or the oxygen concentration of the ambient air). For example, the controller unit 180 and / or the controller 145 may determine how much nitrogen to add to the incoming air gas (and / or the ambient air) to reduce the oxygen concentration of the incoming air gas to the selected oxygen concentration. The gas reservoir manager 526 may maintain a database that associates the target oxygen concentration and the oxygen concentration of the incoming air gas source 230 with the control set points of the mass flow controller 266, the mass flow controller 278, and / or the back pressure regulator 268 to achieve a gas mixture having a target oxygen concentration. The gas mixing system 140 may fill the gas reservoir 270 with the gas mixture. The gas mixing system 140 may then measure the oxygen concentration of the gas mixture in the gas reservoir 270 to ensure that the gas mixture has a target oxygen concentration.

[0075] In some embodiments, in addition to being able to reduce the oxygen concentration of the incoming air gas source 230 to a target oxygen concentration using the nitrogen source 220, the gas mixing system 140 can also be configured to increase the oxygen concentration of the incoming air gas source 230 to a target oxygen concentration using the oxygen source 210. For example, the gas mixing system 140 can include a gas conduit from the oxygen conduit 212 to the gas reservoir inlet conduit 269, the gas conduit including a mass flow controller and a check valve.

[0076] The process 600 may also include verifying the gas mixture in the gas reservoir (block 660) and performing a combustion test using the reservoir gas mixture (block 670). The gas mixing system 140 may measure the oxygen concentration of the gas mixture in the gas reservoir 270 to determine whether the gas mixture in the gas reservoir 270 has a selected target oxygen concentration. For example, the gas mixing system 140 may control the gas mixing manifold 260 to discharge the reservoir gas mixture to the gas mixing manifold conduit 261, and control the gas selection valve 240 to select the reservoir gas mixture from the gas mixing manifold conduit 261 through the oxygen sensor 150 to measure the oxygen concentration and / or total pressure in the gas reservoir 270. If the oxygen concentration and / or total pressure in the gas reservoir 270 corresponds to the selected oxygen concentration and / or total pressure, the gas mixing system 140 may continue to perform the combustion test by controlling the regulator 274 to deliver the gas mixture from the gas reservoir 270 to the chamber interior 112 during the combustion test. If the oxygen concentration and / or total pressure in the gas reservoir 270 does not correspond to the selected oxygen concentration and / or total pressure, the gas mixing system 140 may not perform the combustion test and may suggest that the operator check the gas reservoir filling process.

[0077] Figure 7 is a flow chart of a second process 700 for generating and using a gas mixture to conduct a combustion test. In some embodiments, Figure 7 The process may be performed by and / or using the constant volume combustion chamber system 100. In other embodiments, Figure 7 Some or all of the processes may be performed by or using another device or a group of devices separate from the constant volume combustor system 100.

[0078] The process 700 may include measuring the oxygen concentration in the gas reservoir (block 710), measuring the pressure in the gas reservoir (block 720), and calculating the oxygen content in the gas reservoir based on the measured oxygen concentration and pressure (block 730). The controller unit 180 and / or the controller 145 may control the gas mixing system 140 to measure the oxygen concentration of the gas reservoir 270 using the oxygen sensor 150 and to measure the pressure in the gas reservoir 270 using the pressure sensor 272. The controller unit 180 and / or the controller 145 may then calculate the number of moles of oxygen and nitrogen in the gas reservoir 270 based on the measured pressure and oxygen concentration using, for example, the ideal gas law and the law of partial pressure. For example, the number of moles of oxygen in the gas reservoir 270 may be calculated as Among them, n O Corresponding to the number of moles of oxygen, C O Corresponding to the measured oxygen concentration, P corresponds to the measured pressure, V corresponds to the volume of the gas reservoir 270 , R corresponds to the ideal gas constant, and T corresponds to the temperature of the gas reservoir 270 .

[0079] The process 700 may also include selecting a target oxygen concentration in the gas reservoir (block 740) and selecting a target pressure in the gas reservoir (block 750). For example, the operator may select an oxygen concentration for a combustion test (e.g., 20% oxygen, etc.) and a pressure in the gas reservoir 270 to deliver the gas mixture at the target pressure during the combustion test. The pressure in the gas reservoir 270 may be selected so that the control regulator 274 may deliver the gas mixture at the target pressure. For example, the pressure in the gas reservoir 270 may be selected to be at least a threshold amount higher than the target pressure.

[0080] The process 700 may also include determining the required amounts of oxygen and nitrogen to obtain the target oxygen concentration at the target pressure in the gas reservoir (block 760), and determining the mixing ratio of incoming air and nitrogen based on the determined required amounts of oxygen and nitrogen (block 770). For example, the controller unit 180 and / or the controller 145 may determine the amounts of oxygen and nitrogen required to produce a gas mixture having a target oxygen concentration and a target pressure in the gas reservoir 270 based on the calculated amounts of oxygen and nitrogen already present in the gas reservoir 270. The controller unit 180 and / or the controller 145 may determine the ratio of incoming air and nitrogen based on the required amounts of oxygen and nitrogen. The controller unit 180 and / or the controller 145 may then set the flow rates of the MFC 266 and the MFC 278 based on the determined ratios.

[0081] The process 700 may also include filling the gas reservoir with the determined mixing ratio of incoming air and nitrogen (block 780). For example, the gas reservoir manager 526 may control the set points of the MFC 266, the MFC 278, and / or the back pressure regulator 268 to achieve a gas mixture having a target oxygen concentration and a target pressure using the determined mixing ratio. The gas mixing system 140 may fill the gas reservoir 270 with the gas mixture. The gas mixing system 140 may then measure the oxygen concentration of the gas mixture in the gas reservoir 270 to ensure that the gas mixture has the target oxygen concentration. In addition, the gas mixing system 140 may measure the pressure within the gas reservoir 270 to ensure that the gas reservoir 270 has been filled to at least the target pressure.

[0082] The process 700 may also include verifying the gas mixture in the gas reservoir (block 790) and performing a combustion test using the reservoir gas mixture (block 795). The gas mixing system 140 may measure the oxygen concentration of the gas mixture in the gas reservoir 270 to determine whether the gas mixture in the gas reservoir 270 has a selected target oxygen concentration. For example, the gas mixing system 140 may control the gas mixing manifold 260 to discharge the reservoir gas mixture to the gas mixing manifold conduit 261, and control the gas selection valve 240 to select the reservoir gas mixture from the gas mixing manifold conduit 261 through the oxygen sensor 150 to measure the oxygen concentration and / or total pressure in the gas reservoir 270. If the oxygen concentration and / or total pressure in the gas reservoir 270 corresponds to the selected oxygen concentration and / or total pressure, the gas mixing system 140 may continue to perform the combustion test by controlling the regulator 274 to deliver the gas mixture from the gas reservoir 270 to the chamber interior 112 during the combustion test. If the oxygen concentration and / or total pressure in the gas reservoir 270 does not correspond to the selected oxygen concentration and / or total pressure, the gas mixing system 140 may not perform the combustion test and may suggest that the operator check the gas reservoir filling process.

[0083] Figure 8 An exemplary gas flow 800 for calibrating an oxygen sensor using nitrogen is shown according to embodiments described herein. Figure 8As shown, before any oxygen measurement is made, the gas flow 800 includes exhausting any residual gas from the oxygen sensor 150, the oxygen conduit 212, the gas selection valve 240, the gas mixing manifold 260, and / or the gas mixing manifold conduit 261 using the exhaust flow 805 via the exhaust valve 242. The gas flow 800 then includes a nitrogen flow 810 from the nitrogen source 220 to the gas mixing manifold 260 via the second nitrogen conduit 229. The gas mixing manifold 260 can be controlled to exhaust nitrogen to the gas mixing manifold conduit 261, and the gas selection valve 240 can be controlled to select nitrogen from the gas mixing manifold conduit 261 to pass through the oxygen sensor 150 to the measured gas outlet 252. The oxygen flow 820 can terminate at the gas selection valve 240. The incoming air flow 830 can terminate at the gas mixing manifold 260.

[0084] Fig. 9 An exemplary gas flow 900 for calibrating an oxygen sensor using oxygen is shown according to embodiments described herein. Fig. 9 As shown, before any oxygen measurement is made, gas flow 900 includes exhausting any residual gas from oxygen sensor 150, oxygen conduit 212, gas selector valve 240, gas mixing manifold 260, and / or gas mixing manifold conduit 261 using exhaust flow 905 via exhaust valve 242. Gas flow 900 then includes oxygen flow 910 from oxygen source 210 via oxygen conduit 212 to gas selector valve 240. Gas selector valve 240 can be controlled to select oxygen from oxygen conduit 212 to measured gas outlet 252 through oxygen sensor 150. Nitrogen flow 920 can terminate at gas mixing manifold 260. Intake air flow 930 can terminate at gas mixing manifold 260.

[0085] Fig.10 An exemplary air flow 1000 for measuring oxygen concentration of incoming air gas according to embodiments described herein is shown. Fig.10As shown, before any oxygen measurement is made, the gas flow 1000 includes exhausting any residual gas from the oxygen sensor 150, the oxygen conduit 212, the gas selection valve 240, the gas mixing manifold 260, and / or the gas mixing manifold conduit 261 using the exhaust flow 1005 via the exhaust valve 242. The gas flow 1000 then includes an incoming air gas flow 1010 from the incoming air gas source 230 to the gas mixing manifold 260 via the second incoming air gas conduit 239. In other embodiments, the incoming air gas flow 1010 can draw ambient air from the incoming air gas source 230 instead of zero-grade air gas. The gas mixing manifold 260 can be controlled to exhaust the incoming air gas to the gas mixing manifold conduit 261, and the gas selection valve 240 can be controlled to select the incoming air gas from the gas mixing manifold conduit 261 to pass through the oxygen sensor 150 to the measured gas outlet 252. The oxygen flow 1020 can terminate at the gas selection valve 240. The nitrogen flow 1030 can terminate at the gas mixing manifold 260.

[0086] Fig.11 An exemplary gas flow 1100 for producing a gas mixture having a specific oxygen concentration according to embodiments described herein is shown. Fig.11 As shown, the gas flow 1100 includes a nitrogen gas flow 1110 from the nitrogen source 220 via the nitrogen conduit 222 through the mass flow controller 266 to the T-interconnect 267 and terminates at the gas mixing manifold 260 via the second nitrogen conduit 229. The mass flow controller 266 can control the amount of nitrogen flowing to the T-interconnect 267 based on the target oxygen concentration and the measured oxygen concentration of the incoming air gas source 230. The gas flow 1100 also includes an incoming air gas flow 1120 from the incoming air gas source 230 via the incoming air gas conduit 232 through the mass flow controller 278 to the T-interconnect 267 and terminates at the gas mixing manifold 260 via the second incoming air gas conduit 239. In other embodiments, the incoming air gas flow 1120 can draw ambient air from the incoming air gas source 230 instead of zero-grade air gas. The mass flow controller 278 can control the amount of incoming air gas flowing to the T-interconnect 267 based on the target oxygen concentration and the measured oxygen concentration of the incoming air gas source 230. The nitrogen and incoming air gas can be mixed at the T-interconnect 267 into a gas mixture having a target oxygen concentration to produce a gas mixture gas stream 1130. The gas mixture gas stream 1130 can fill the gas reservoir 270 and stop flowing at the gas mixing manifold 260 and the regulator 274. The oxygen flow 1140 can terminate at the gas selection valve 240.

[0087] Fig.12 An exemplary gas flow 1200 for measuring the oxygen concentration of a generated gas mixture is shown according to embodiments described herein. Fig.12 As shown, before any oxygen measurement is made, the gas flow 1200 includes exhausting any residual gas from the oxygen sensor 150, the oxygen conduit 212, the gas selection valve 240, the gas mixing manifold 260, and / or the gas mixing manifold conduit 261 using the exhaust flow 1205 via the exhaust valve 242. The gas flow 1200 then includes a gas reservoir gas mixture flow 1210 from the gas reservoir 270 to the gas mixing manifold 260 via the gas reservoir outlet conduit 271. The gas mixing manifold 260 can be controlled to exhaust the reservoir gas mixture to the gas mixing manifold conduit 261, and the gas selection valve 240 can be controlled to select the reservoir gas mixture from the gas mixing manifold conduit 261 through the oxygen sensor 150 to the measured gas outlet 252. The oxygen flow 1220 can terminate at the gas selection valve 240. The nitrogen flow 1230 can terminate at the gas mixing manifold 260. The incoming air flow 1240 can terminate at the gas mixing manifold 260.

[0088] This application incorporates by reference the following applications: Attorney Docket No. 0080-1310PR, Application No. 63 / 380,004, entitled "Prediction of Motor Octane Number Using a Constant Volume Combustion Chamber"; and Attorney Docket No. 0080-1311PR, Application No. 63 / 380,005, entitled "Prediction of Research Octane Number Using a Constant Volume Combustion Chamber"

[0089] In the foregoing patent specification, various preferred embodiments have been described with reference to the accompanying drawings. However, it will be apparent that various modifications and changes may be made thereto, and additional embodiments may be implemented, without departing from the broader scope of the invention as described in the appended claims. Accordingly, the patent specification and drawings should be regarded as illustrative rather than restrictive.

[0090] For example, although reference has been made to Figure 6 and Figure 7 A series of blocks are described, but the order of the blocks may be modified in other implementations. In addition, non-dependent blocks and / or signals may be executed in parallel.

[0091] It will be apparent that the systems and / or methods described above may be implemented in many different forms of software, firmware, and hardware in the embodiments shown in the figures. The actual software code or dedicated control hardware used to implement these systems and methods does not limit the embodiments. Therefore, the operation and behavior of the systems and methods are described without reference to specific software code - it is understood that software and control hardware can be designed to implement the systems and methods based on the description herein.

[0092] In addition, some of the above parts may be implemented as components that perform one or more functions. As used herein, components may include hardware (eg, processor, ASIC or FPGA) or a combination of hardware and software (eg, software executed by a processor).

[0093] It should be emphasized that when used in this patent specification, the terms "include" / "comprising" are used to specify the presence of stated features, integers, steps or components, but do not exclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0094] The term "logic" as used herein may refer to a combination of one or more processors configured to execute instructions stored in one or more storage devices, may refer to hardwired circuits, and / or may refer to a combination thereof. In addition, logic may be included in a single device or may be distributed across multiple (possibly remote) devices.

[0095] For purposes of describing and defining the present invention, it should also be noted that the term "substantially" is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term "substantially" is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.

[0096] Unless explicitly described, any element, behavior, or instruction used in this application should not be interpreted as being essential or essential to the embodiment. In addition, as used herein, the article "a" is intended to include one or more items. In addition, unless explicitly stated otherwise, the term "based on" is intended to mean "based at least in part on".

Claims

1. A gas mixing system comprising: a first conduit for receiving nitrogen; a second conduit for receiving incoming air gas; a gas reservoir coupled to the first conduit and the second conduit; a gas mixing manifold coupled to the gas reservoir, the first conduit, and the second conduit; an oxygen sensor coupled to the gas mixing manifold; and A controller configured to: Selecting a target oxygen concentration for the gas mixture used in the combustion test; measuring, using the oxygen sensor, the oxygen concentration in the intake air gas received via the second conduit; controlling a nitrogen flow rate in the first conduit and an intake air gas flow rate in the second conduit to fill the gas reservoir with a gas mixture having a selected target oxygen concentration based on a measured oxygen concentration in the intake air gas; as well as The discharge of the gas mixture from the gas reservoir is controlled for use in a combustion test.

2. The gas mixing system according to claim 1, wherein: The controller is also configured to: The oxygen concentration of the gas mixture in the gas reservoir is measured using the oxygen sensor to determine whether the gas mixture in the gas reservoir has the selected target oxygen concentration.

3. The gas mixing system according to claim 1, wherein: The gas mixing system also includes: a third conduit for receiving oxygen; and A valve is provided for selecting between oxygen from the third conduit and gas from the gas mixing manifold.

4. The gas mixing system according to claim 3, wherein: The controller is also configured to: The oxygen sensor is calibrated using oxygen from the third conduit.

5. The gas mixing system according to claim 3, wherein: The controller is also configured to: The oxygen sensor is calibrated using nitrogen from the first conduit.

6. The gas mixing system of claim 3, wherein: The third conduit is connected to the gas reservoir, and the controller is further configured to: A nitrogen flow rate in the first conduit and an oxygen flow rate in the third conduit are controlled to fill the gas reservoir with a synthetic air gas mixture having the selected target oxygen concentration.

7. The gas mixing system of claim 1, wherein: The gas mixing system also includes: A first mass flow controller is used to control the flow rate of nitrogen in the first conduit.

8. The gas mixing system of claim 7, wherein: The gas mixing system also includes: a second mass flow controller for controlling the flow of incoming air gas in the second conduit; and A back pressure regulator is connected from the first mass flow controller and the second mass controller to the gas reservoir.

9. The gas mixing system of claim 1, wherein: The gas mixing system also includes: A vent valve is connected to the oxygen sensor and is configured to vent gas from a conduit connected to the oxygen sensor.

10. The gas mixing system of claim 1, wherein: The gas mixing system also includes: A pressure regulator is connected to the gas reservoir and is configured to control an outlet pressure of the gas reservoir.

11. A method comprising: selecting, by a controller of the gas mixing system, a target oxygen concentration of the gas mixture for the combustion test; measuring, by the controller and using an oxygen sensor, the oxygen concentration in an incoming air gas source or an ambient air source received by the gas mixing device; controlling, by the controller, a nitrogen flow rate and an intake air gas flow rate from the intake air gas source or the ambient air from the ambient air source to fill a gas reservoir of the gas mixing system with the gas mixture having the selected target oxygen concentration based on a measured oxygen concentration in the intake air gas or the ambient air; as well as The gas mixture from the gas reservoir is outputted by the controller for use in the combustion test.

12. The method of claim 11, wherein: The method further comprises: The oxygen concentration of the gas mixture in the gas reservoir is measured to determine whether the gas mixture in the gas reservoir has the selected target oxygen concentration.

13. The method of claim 11, wherein: The method further comprises: The oxygen sensor is calibrated using oxygen from an oxygen source.

14. The method of claim 11, wherein: The method further comprises: The oxygen sensor was calibrated using nitrogen from a nitrogen source.

15. The method of claim 11, wherein: The method further comprises: The nitrogen flow rate and the oxygen flow rate from the oxygen source are controlled to fill the gas reservoir with a synthetic air gas mixture having the selected target oxygen concentration.

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