Abstract:
A system is provided for monitoring and testing engine emissions during normal operations. The system monitors and logs engine data to determine when the engine is operating at a steady-state within a defined test mode. The system may measure and log multiple sets of emissions data while the engine is operating in the defined test mode. The multiple sets of emissions data may be aggregated for qualifying the engine and may provide trend information about the engine. The test mode definition may be revised based on the logged engine data. The system may be used to selectively monitor one or more of a set of multiple engines.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims the priority and benefit of U.S. patent application No. 61/286,018 titled “Emissions Control System,” filed Dec. 14, 2009 and U.S. patent application No. 61/266,516 titled “Engine Emission Control,” filed Dec. 4, 2009. The disclosures of all of the above U.S. patent applications are incorporated by reference herein in their entirety. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The present disclosure generally relates to emission control systems. The present disclosure more specifically relates to monitoring and sampling emissions from an engine for testing during operation. 
         [0004]    2. Description of Related Art 
         [0005]    Emissions and emissions control systems on ship engines must be tested periodically. Authorities such as US Environmental Protection Agency (EPA) and British Standards Institute (BSI) specify testing protocols for ship engines. Tested emissions include Oxygen (O 2 ), Hydrocarbons (HC), Non-methane hydrocarbons (NMHC), Oxides of nitrogen (NOx), Sulfur dioxide (SO 2 ), Ammonia (NH 3 ), Dinitrogen oxide (N 2 O), Formaldehyde (HCHO), Methanol (CH 3 OH), particulate matter (PM), and oxides of carbon (CO x ) (e.g., Carbon monoxide (CO), Carbon dioxide (CO 2 ), etc.). Engine operating conditions are measured during testing. Measured engine parameters include speed, engine (RPM), torque, power, temperature, fuel flow or consumption, air flow or consumption, and exhaust gas flow, engine intake air temperature and pressure, and exhaust gas temperature and pressure. 
         [0006]    Particulate materials comprise primarily carbon, condensed hydrocarbons, and sulfates and associated water. Particulate collection and measurement methods may reflect legal requirements (e.g., in the USA and European Union). For example, regulations may require particulate material in exhaust gases to be collected on a specified filter medium after diluting the exhaust gases using clean, filtered air to a specified temperature range as measured at a point upstream of a primary filter. 
         [0007]    Emissions control tests typically include a collection of data during steady-state test cycles or profiles. The profiles are designed for various classes of engines and equipment. Each of these test profiles represent a sequence of one or more test modes and steady-states during which emissions are measured. A weighting factor may be applied to emissions measurements for each mode. A test mode for an engine operation is defined in a test profile as an area on an engine speed-power map. The test profile may define a steady-state for a test mode as operating the engine for a set period of time (e.g., six minutes) within the test mode. 
         [0008]      FIG. 1A  is a speed-power map  100  for an engine, according to prior art. The horizontal axis of  FIG. 1A  represents percent rated speed of an engine and the vertical axis represents percent rated power of the engine. The speed-power map  100  includes a power curve  110  for the engine. Line A-B of the power curve  110  illustrates maximum rated power for the engine. The maximum rated power (rated power) for an engine is a maximum continuous power to be used with the engine. The rated power is typically set somewhat lower than the maximum available power from the engine. Line B-C illustrates the maximum rated speed of the engine. The maximum rated speed (rated speed) for an engine is a maximum continuous speed at which to operate the engine. The rated speed is typically set somewhat lower than the maximum speed the engine can achieve. Line C-D illustrates idling power over a range of speeds. Line D-E illustrates minimum speed for operating the engine. Line E-A illustrates maximum torque for the engine. 
         [0009]    The speed-power map  100  of  FIG. 1A  includes test modes  1 - 4 . Test modes  1 - 4  are represented by an area of the speed-power map  100 . The area representing test mode  1  includes 95-105% rated speed, which is a target speed of 100% plus or minus 5% of the rated speed. The area also includes 95-105% rated power for an engine, which is a target power of 100% plus or minus 5% of the rated power. Thus, in test mode  1 , the engine is run at about 100% rated speed and 100% rated power. In test mode  2  the engine is run at a target of about 91% rated speed and 75% rated power. In test mode  3 , the engine is run at a target of about 80% rated speed and 50% rated power. In test mode  4 , the engine is run at a target of about 63% rated speed and 25% rated power, at that speed. The rated power at 63% speed in  FIG. 1A  may be represented by point F along the maximum torque line E-A. The area representing each of the test modes  1 - 4  of  FIG. 1A  includes plus or minus 5% of the target speed and power. However, a larger or smaller area may be specified about each test mode on the speed-power map  100 . 
         [0010]      FIG. 1B  illustrates a test profile  120  for the speed-power map  100  of  FIG. 1 , according to prior art. The horizontal axis of  FIG. 1B  represents time and the vertical axis represents percent rated power. The test profile  120  illustrates an emissions testing sequence of settings and times for collecting emission data in test modes  1 - 4  during a steady-state in each mode. The test profile  120  specifies that the engine is to be operated in each test mode for six minutes and that emission data is to be collected during the final three minutes of each test mode. Transitions between test modes are made over a short period of time, as quickly as practicable. 
         [0011]    The test profile  120  of  FIG. 1B  illustrates transitioning power and speed from about 0% to the full power of test mode  1 . Test mode  1  is then maintained at a steady-state for a period of time specified by test profile  120 . Test mode  1  illustrated in  FIG. 1B  has a duration of six minutes and emission data  1  is collected during the final three minutes of the test mode  1 . The test profile  120  further specifies that after operating the engine in test mode  1  for six minutes the engine is transitioned to test mode  2  where it is operated for six minutes, then transitioned to test mode  3  where it is operated for six minutes, and then transitioned to test mode  4  where it is operated for six minutes. The test profile further specifies that emission data  2 ,  3 , and  4  are collected during the final three minutes of the six minute steady-state in test modes  2 ,  3  and  4 , respectively. A weight W 1 , W 2 , W 3 , and W 4  is applied to each of emission data  1 , data  2 , data  3 , and data  4 , respectively, according to the equation: 
         [0000]        E= data1 *W   1 +data1 *W   2 +data1 *W   3 +data1*W 4    
         [0000]    where E is a total emission number E that is calculated from a sum of the weighted data. 
         [0012]    Speed-power maps, test modes, and test profiles are further described in ISO 8178 which is incorporated by reference herein in its entirety. The steady-state test modes such as those illustrated in  FIGS. 1A and 1B  and ISO documents are selected to represent a standard usage expected for an engine. 
         [0013]    Unfortunately, many engines are normally operated during a majority of the time in one or more modes that are not represented by any of the test modes in any of the standard test profiles. Thus, emissions data do not accurately reflect actual emissions produced by many engines during normal operation. 
       SUMMARY OF THE CLAIMED INVENTION 
       [0014]    In an embodiment of the presently claimed invention, a system is provided for monitoring exhaust emissions. The system monitors engine parameters during normal operations to determine if the engine is in a steady-state and operating within a test mode. The test mode may be defined by the engine parameters and a period of time in a steady-state. The system may measure exhaust emissions while the engine is operating in the test mode. The system may suspend emissions measurements while the engine is not in the test mode. The system may measure and log multiple sets of emissions data for during normal operations within the defined test mode. The multiple sets of emissions data may be aggregated for qualifying the engine for use. The multiple data sets may also provide trend information about the engine. The multiple data sets may further be used to revise the test mode definition to more accurately reflect the total emissions and use of the engine. The system may be used to selectively monitor and/or measure one or more of multiple engines. 
         [0015]    In an embodiment of the presently claimed invention, a method is provided for monitoring emissions from an engine onboard a ship. The method includes monitoring engine data using a computer system and storing the monitored engine data in the computer system. The method further includes using the computer system to determine if the engine is operating in a steady-state based on the stored engine data. The computer also compares the monitored engine data with a test mode definition in a test profile database to determine if the engine is operating within a test mode. An emissions detector is fluidly connected to the engine exhaust gas based on the steady-state determination and the test mode determination. The coupled emissions detector is activated based on the test profile data while the engine is operating within the test mode. The computer system receives and stores emissions data from the activated emissions detector. The received data represents emissions in the engine exhaust gas during the steady-state. The method further includes updating the test mode definition in the test profile database based on the monitored engine data. The method also includes performing the steps of determining if the engine is operating in a steady state and test mode, comparing engine data with the test mode definition, and receiving and storing emissions data multiple times during normal operation. 
         [0016]    In an embodiment of the presently claimed invention, a system is provided for monitoring engine exhaust gas emissions. The system includes an engine monitor configured to receive a stream of engine data from engine sensors during normal operations of the engine, and an engine data log configured to store the stream of engine data. The system further includes an emissions detector module under computer control that is configured for fluid coupling and un-coupling to the engine exhaust gas. The emissions detector module includes sensors configured for measuring the engine exhaust gas emissions. The system further includes an emissions data log and a test profile database. The emissions data log stores measured emissions data from the emissions detector module. The test profile database is stores an emission test profile and a test mode definition. The system also includes a computer system coupled to the engine monitor and the emissions detector module. The computer system is configured to determine if the engine is in a steady-state based on the stream of engine data and if the engine is operating within the test mode based on a comparison of the test mode definition to the stream of engine data. The computer system couples the emissions detector module to the engine exhaust gas for execution of the emission test profile when the engine is operating within the test mode. The computer system is also configured to modify the test mode definition in the test profile database using the stream of engine data. 
         [0017]    In an embodiment of the presently claimed invention, an emission detector system is provided for monitoring engine exhaust gas emissions onboard a ship. The system includes a computer system that is configured to control a valve, a heater, a compressor, an orifice array, an emissions detector, and an accelerometer. The valve is configured to couple the emissions detector system selectively to exhaust gas from either a first engine or a second engine. The heater is configured to heat the engine exhaust gas. The compressor is configured to provide the exhaust gas at a target pressure to the orifice array, which controls the flow rate of a stream of exhaust gas to the emissions detector. The emissions sensor is configured to measure emissions in the exhaust gas received from the orifice array. The accelerometer is configured to detect motion of the emissions detector system. The computer system is configured to suspend measurements of emissions based on detection of excessive acceleration of the emissions detector system. The emissions sensor may be an O 2  sensor configured to measure oxygen, a HC sensor configured to measure hydrocarbons, a PM sensor configured to measure particulate matter, or a COx sensor configured to measure oxides of carbon such as CO, CO 2 , and etc. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0018]      FIG. 1A  is a speed-power map for an engine illustrating a test profile, according to prior art. 
           [0019]      FIG. 1B  illustrates a test profile for the speed-power map of  FIG. 1A , according to prior art. 
           [0020]      FIGS. 2A-2C  are block diagrams illustrating prior art configurations of engine systems for use in a ship, according to prior art. 
           [0021]      FIG. 3  is a block diagram illustrating a system for monitoring emissions from engines according to aspects of the invention. 
           [0022]      FIG. 4  is a block diagram illustrating details of an emissions detector module of  FIG. 3 . 
           [0023]      FIG. 5  is a block diagram illustrating details of a computer system of  FIG. 3 . 
           [0024]      FIG. 6  is a flow diagram of an exemplary process for monitoring emissions from an engine. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]      FIGS. 2A-2C  are block diagrams illustrating prior art configurations of engine systems  200 ,  240 , and  250  for use in a ship.  FIG. 2A  is a block diagram illustrating engine system  200 . Engine system  200  includes engines  210  and a transmission  220 . One engine  210  may be idled or shut down while the other engine  210  provides power, for example, when power from only one engine  210  is required. The transmission  220  may couple power from the engines  210  to a driveshaft  222  to turn a drive  224 . Examples of the drive  224  include a propeller, a turbine a jet, etc. The transmission  220  may couple power from either or both engines  210 . In some embodiments, each engine  210  includes a separate transmission  220 , driveshaft  222  and drive  224 . The transmission  220  typically includes a reduction gear. While the engine system  200  illustrates two engines  210  coupled to the transmission  220 , fewer or more engines  210  may coupled to the transmission  220  in the engine system  200 . 
         [0026]    The engine system  200  further includes motor-generators  230 . Each motor-generator  230  includes an engine  210  configured to drive a generator  226 . The generator  226  may produce electricity for use in ship systems such as lights, instruments, actuators, environmental controls, etc. The motor-generators  230  illustrated in the engine system  200  are independent of the engines  210  coupled to the transmission  220 . One motor-generator  230  may be run at idle or shut down while the other motor-generator  230  provides power, for example, when power from only one motor-generator  230  is required. While the system  200  illustrates two motor-generators  230  fewer or more motor-generators  230  may used in the system  200 . 
         [0027]      FIG. 2B  is a block diagram illustrating engine system  240 . The engine system  240  differs from the engine system  200  in that the generators  226  of the motor-generators  230  are configured to provide electric power to an electric motor  228  which converts electric power from the motor-generators  230  to mechanical power. The electric motor  228  of system  240  is mechanically coupled to the transmission  220 . Either or both of the motor-generators  230  may be coupled to the electric motor  228  using a switching system (not illustrated). Engine systems  200  and  240  may be considered hybrid systems in that they use separate engines for producing mechanical power and electrical power. While the system  240  illustrates two engines  210  configured to mechanically drive the transmission  220  and two motor-generators  230  fewer or more engines  210  and/or motor-generators  230  may used in the system  200 . 
         [0028]      FIG. 2C  is a block diagram illustrating engine system  250 . The engine system  250  differs from the engine system  240  in that the engine system  250  includes only motor-generators  230 . Power to the transmission is provided entirely from the motor-generators  230  via the electric motor  228 . One or more motor-generator  230  may be idled or shut down while the remaining motor-generators  230  provide power. More than one electric motor  228  may be coupled to the motor-generators  230 . For example, each motor-generator  230  may be coupled to a separate electric motor  228  which is, in turn, mechanically coupled to one or more transmission  220 . While the system  250  illustrates four motor-generators  230 , fewer or more motor-generators  230  may used in the system  200 . 
         [0029]      FIG. 3  is a block diagram illustrating a system  300  for monitoring emissions from one or more engines  210 , according to aspects of the invention. The engines  210  of  FIG. 3  may be used, for example, in the configurations of engine systems  200 ,  240 , and  250 . System  300  includes a computer system  302  in communication with an engine monitor  304  and an emissions detector module  310 . The engines  210  of  FIG. 3  include internal combustion engines, external combustion engines, reciprocating, rotary, diesel, gas, steam, stirling, turbine engines, hybrid cycle, separate cycle, and combined cycle engines. 
         [0030]    The engine monitor  304  may be coupled to one or more engines  210  and/or generators  226  and configured to receive data representing operation of the engine  210 . The received data includes speed, RPM, torque, power, temperature, fuel flow or consumption, air flow or consumption, exhaust gas flow, engine intake air temperature and pressure, exhaust gas temperature and pressure. Power can be derived from RPM and Torque. Power data may be measured in the form of electrical power generated by the motor generator  230 . Optionally, the engine monitor  304  receives data from accelerometers coupled to the engine  210 , exhaust manifold  322 , emissions control  324 , emissions control  334 , generator  226 , and/or ship. The accelerometer data may be used to determine acceleration associated with impact, motion, vibration, and shaking, due to maneuvering, wave action, storms, and etc. The accelerometer data may be used for determining if the engines  210  are in a steady-state. 
         [0031]    The emissions detector module  310  is configured for being selectively coupled to an emissions manifold  312  and/or emissions manifold  314 . The emissions manifold  312  may be coupled to a valve  328  and/or  326  for receiving exhaust gas from the engine  210 . The valve  326  is configured to direct exhaust gas sampled upstream of an emissions control device  324  into the emissions manifold  312 . The valve  328  is configured to direct exhaust gas sampled downstream of the emissions control device  324  into the emissions manifold  312 . The valves  326  and/or  328  may be controlled using the computer system  302 . 
         [0032]    Similarly, the emissions manifold  314  may be coupled to a valve  338  and/or  336  for receiving exhaust gas from the engine  210  of the motor-generator  230 . The valve  336  is configured to direct exhaust gas sampled upstream of an emissions control device  334  into the emissions manifold  314 . The valve  338  is configured to direct exhaust gas sampled downstream of the emissions control device  334  into the emissions manifold  314 . The valves  336  and/or  338  may be controlled using the computer system  302 . Thus, the emissions detector module  310  may be configured to sample exhaust gas from one or more engine  210 . 
         [0033]    The emissions detector module  310  may be physically moved between multiple engines  210 . For example emissions detector module  310  of  FIG. 3  may be physically moved from a physical connection at the emissions manifold  314  at the engine  210  of the motor-generator  230  to another engine  210  for connection to the emissions manifold  312 . Alternatively, the emissions detector module  310  may be coupled to both the emissions manifold  312  and  314  at the same time. 
         [0034]    While two engines  210  are illustrated in  FIG. 3 , the engine monitor  304  may be configured to monitor more or fewer engines  210 . Similarly, the emissions detector module  310  may be configured to sample exhaust from more or fewer engines  210 . 
         [0035]      FIG. 4  is a block diagram illustrating details of the emissions detector module  310  of  FIG. 3 . The emissions detector module  310  includes an intake manifold  402  and a valve  404 . The intake manifold  402  is configured for coupling to one or more emissions manifold such as emissions manifold  312  and  314 . The intake manifold  402  may be heated for maintaining the exhaust gas at a desired temperature. 
         [0036]    The valve  404  may be used for isolating the emissions detector module  310  when not in use or during repositioning. The emissions detector module  310  may be portable for physically moving between emissions manifold  312  and  314 . For example, upon determining that the engine  210  coupled to the transmission  220  is operating in a steady-state test mode, the emissions detector module  310  may be repositioned and connected to the emissions manifold  312  for collection of emissions data. Similarly, upon determining that the engine  210  in the motor generator  230  is operating in a steady-state test mode, the emissions detector module  310  may be repositioned and connected to the emissions manifold  314 . The intake manifold  402 , emissions manifold  312 , and emissions manifold  314  may be fitted with quick disconnect fittings for ease of connecting and disconnecting. The valve  404  may isolate the intake manifold  402  while the manifold  402  is disconnected during repositioning of the emissions detector module  310 . 
         [0037]    Alternatively, the intake manifold may be connected to both the emissions manifold  312  and  314 . The valve  404  may be configured for selecting between the emissions manifolds  312  and  314 . The valve  404  of  FIG. 4  is under control of the computer system  302  for isolating the emissions detector module  310  and/or selectively admitting exhaust gas from emissions manifold  312  and/or  314 . 
         [0038]    The emissions detector module  310  of  FIG. 4  further includes a COx detector  410 , a NOx detector  420 , an  02  detector  430 , a HC detector  440 , and a PM detector  450  (emissions detectors  410 - 450 ). The emissions detectors  410 - 450  are communication with the computer system  302 . The emissions detectors  410 - 450  are representative of various detectors that may be used in the emissions detector module  310 . One or more of the emissions detectors  410 - 450  may be omitted. Alternatively, one or more additional detectors (e.g., NMHC, SO 2 , NH 3 , N 2 O, HCHO, CH 3 OH, and etc.) may be used in place of and/or in addition to the emissions detectors  410 - 450 . 
         [0039]    The emissions detector module  310  of  FIG. 4  further includes a pump  406  and an orifice array  408 . The pump  406  may include a compressor and is configured for maintaining the exhaust gas at a target pressure and flow to the orifice array  408 . The pump  406  may include a heater for maintaining the exhaust gas at a target temperature for analysis by the emissions detectors  410 - 450 . The computer system  302  may control the pump  406  and/or heater to achieve a set point for the target pressure, flow and/or temperature of the exhaust gas to the orifice array  408 . 
         [0040]    The orifice array  408  includes one or more apertures or nozzles configured to receive exhaust gas from the pump  406  and meter or control the exhaust gas to the emissions detectors  410 - 450 . Each aperture in the orifice array  408  may be sized to control the flow of the exhaust gas to one or more of the emissions detectors  410 - 450  at a given pressure maintained by the pump  406 . For example, a first aperture in the orifice array  408  may be in fluid communication with the COx detector  410 , a second aperture in fluid communication with the NOx detector  420 , and a third aperture in fluid communication with three detectors, namely the  02  detector  430 , the HC detector  440 , and the PM detector  450 . At a pressure of  1 . 3  atmospheres maintained by the pump  406 , the first aperture may restrict the flow of exhaust gas to a rate of  10  ml per minute, the second aperture may restrict the flow of exhaust gas to  5  ml per minute, and the third aperture may restrict the flow of exhaust gas to  100  ml per minute. Optionally, one or more of the apertures in the orifice array  408  includes a valve (not illustrated) configured to isolate or block flow of the exhaust gas through the aperture. 
         [0041]    The emissions detector module  310  of  FIG. 4  further includes an accelerometer  460 . The accelerometer  460  is configured to provide data to the computer system  302  representing acceleration and/or oscillation of the emissions detector module  310 . The computer system  302  may use the data to determine if the emissions detector module  310  is subject to impact, motion, vibration, and shaking, due to maneuvering, storms, heavy seas, or waves. Excessive acceleration may result in inaccurate measurements by the emissions detectors  410 - 450 . For example, particulate matter may be dislodged from the insides of various parts such as manifolds, tubing, ducts, orifices, and valves within the emissions detector module  310 , thus, resulting in abnormally high particle measurements. 
         [0042]    The emissions detector module  310  includes an optional transmitter module  470 . The transmitter module  470  may provide communication between the emissions detector module  310  and the computer system  302  and/or the engine monitor  304 . In some embodiments, one or more of the emissions detectors  410 - 450  are located external to the emissions detector module  310  (e.g., on the engine  210 , the manifold  322 , and/or the emissions control system  324 ). The transmitter module  470  may provide communication between the emissions detector module  310  and the one or more externally located emissions detectors  410 - 450 . The transmitter module  470  may also provide communication between the emissions detector module  310  and sensors configured to transmit data representing operation of the engine  210 . Various modes of communication via the transmitter module  470  include wireless, infrared, intranet, internet, satellite, LAN, WAN, optical fiber, cell, ship to shore, ship to ship, and etc. 
         [0043]      FIG. 5  is a block diagram illustrating details of the computer system  302  of  FIG. 3 . The computer system  302  of  FIG. 5  includes a data log  510 , a mode module  520 , a test profile database  530 , a test module  540 , an emission data log  550 , and an optional transmitter module  560 . The data log  510  is configured to receive a stream of engine data from the engine monitor  304  and store the data. The mode module  520  is configured to analyze the data in the data log  510  and use the analysis to determine a test mode definition for the engine  210 . The test profile database  530  is configured to store a test profile and the test mode definition determined by the mode module  520 . The test module  540  is configured to analyze the stream of engine data in the data log  510  to determine if the engine  210  is in a steady-state. The test module  540  is further configured to compare the test mode definition in the test profile database  530  to the stream of data in the data log  510  to determine if the engine  210  is operating in a test mode. The test module  540  may execute the test profile in the test profile database  530  when the engine is in a steady-state and a test mode. The emission data log  550  is configured to receive emissions data from the emissions detector module  310 . 
         [0044]    The transmitter module  560  is a software and/or hardware interface configured to provide communication between the computer system  302  and another computer system, such as a shore based computer system. The transmitter module  560  may also provide communication between the computer system  302  and the engine monitor  304  and/or the emissions detector module  310 . The transmitter module  560  may receive engine data from detectors disposed on the engine  210 . Various modes of communication via the transmitter module  560  include wireless, infrared, intranet, internet, LAN, WAN, satellite, optical fiber, cell, ship to shore, ship to ship, and etc. 
         [0045]    While the data log  510 , mode module  520 , test profile database  530 , test module  540 , emission data log  550 , and transmitter module  560  are illustrated as part of a single computer, these modules may be distributed among multiple computers that collectively comprise computer system  302 . For example, the transmitter module  560  may be configured to transmit engine data and emission data to between computers, including a shore based computer system (not illustrated), for storage in a data log  510 , and emission data log  550 , respectively in the shore base computer system. 
         [0046]      FIG. 6  is a flow diagram of an exemplary process  600  for monitoring emissions from an engine  210 . In step  602 , engine data is monitored (e.g., using the engine monitor  304 ). In step  604 , the monitored engine data is stored in the computer system  302  (e.g., in the data log  510 ). In step  606 , the computer system  302  uses stored engine data to determine if the engine is operating in a steady state. Optionally, the computer system  302  uses accelerometer data (e.g., from the engine, the engine manifold, emissions control, the engine monitor, and/or emissions detector) to determine if the engine is operating in a steady state. In step  608 , the computer system  302  (e.g., the test module  540  or the mode module  520 ) compares the monitored engine data to a test mode definition in the test profile database  530  to determine if the engine is operating within a test mode. Optionally, the computer system  302  uses accelerometer data from the engine manifold, emissions control, and/or emissions detector module  310  determine if the engine  210  is operating within a test mode. 
         [0047]    In step  610 , one or more detectors (e.g., emissions detectors  410 - 450 ) in the emissions detector module  310  are fluidly coupled to the engine exhaust gas when the engine  210  is in a steady-state and/or in a test mode. In step  612 , one or more detectors in the emissions detector module  310  are activated while the engine  210  is operating within the test mode at a steady state. In step  614 , the computer system  302  receives data from the one or more activated emissions representing emissions in the engine exhaust gas during the steady-state. In step  616 , the emissions data is stored (e.g., in the in the emission data log  550  of the computer system  302 ). The steps  610 - 616  may be repeated multiple times for a particular test mode during normal operations of the engine  210 . The emission data may be aggregated for the test mode to provide an average of emissions and a trend for the emissions in that test mode. 
         [0048]    Multiple test modes may be defined for the engine  210 . The steps  610 - 616  may be repeated multiple times for each defined test modes during normal operations of the engine  210 . The emission data for each of the defined test modes may be aggregated. The aggregated emission data may provide an average emission and a trend for the emissions for each of the test modes. 
         [0049]    In step  618 , the test mode definition in the test profile database  530  is updated based on the monitored engine data. The mode module  520  may determine a new test mode definition based on an analysis of the engine data and provide the new definition to the test profile database  530 . Steps  610 - 618  may be repeated multiple times and the test mode definition may be modified multiple times. Each of multiple test mode definitions may be modified multiple times. 
         [0050]    Several embodiments are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations are covered by the above teachings and within the scope of the appended claims without departing from the spirit and intended scope thereof. For example, the engine systems  200 ,  240 , and  250  are described for a ship, however, these systems may be used for other applications, including power plants, land vehicles, aircraft, and etc. Various embodiments of the invention include logic stored on computer readable media, the logic configured to perform methods of the invention. 
         [0051]    The embodiments discussed herein are illustrative of the present invention. As these embodiments of the present invention are described with reference to illustrations, various modifications or adaptations of the methods and/or specific structures described may become apparent to those skilled in the art. All such modifications, adaptations, or variations that rely upon the teachings of the present invention, and through which these teachings have advanced the art, are considered to be within the spirit and scope of the present invention. Hence, these descriptions and drawings should not be considered in a limiting sense, as it is understood that the present invention is in no way limited to only the embodiments illustrated.