210, second filter 212, third filter 214 and fourth filter 216 are all preferably different particle sizes. For example, the first filter 210 is a 10 μm filter, the second filter 212 is a 1.0 μm filter, the third filter 214 is a 0.45 μm filter and the fourth filter 216 is a wire mesh. The filter sizes can be any size that adequately eliminates the entry of particles that are greater than 2 μm to prevent infrared (IR) dispersion and eliminate as many particulates which are less than 2 μm to ensure that the gas absorption cell 240 discussed below does not suffer from precipitation of small particles within the sample chamber.

Gas Absorption Cell

An example of the gas absorption cell 240 utilizing non-dispersive infrared absorption spectrometry (NDIR-AS) is shown in FIG. 6. From the exhaust 219 of the exhaust flange 218, exhaust gas vapor passes into the intake port 241 of the gas absorption cell 240.

The gas absorption cell 240 has a first end 240a with an emitter 242 and a second end 240b with a detector 243, and a length L between the emitter 242 and the detector 243 forming a sample chamber 244. The intake port 241 and the exhaust port 245 are between the emitter 242 and the detector 243 along the length L of the sample chamber 244 of the gas absorption cell 240. In one embodiment the sample chamber 244 has a length of at least 28.5 cm.

The emitter 240 at the first end 240a has a reflector 247 and an infrared source 246. The detector 243 at the second end 240b includes one or more passband filters 248 and an infrared detector 249. The infrared light from the infrared source 246 is directed through the sample chamber 244 towards the detector 243. Sensors 251 may be present within the sample chamber 244 for gas pressure and gas temperature. The location of the sensors 251 in FIG. 6 is for illustration purposes only and can be anywhere within the sample chamber 244. The gas in the sample chamber 244 causes absorption of specific wavelengths and the attenuation of these wavelengths is measured by the detector 243 to determine the gas concentration. One or more passband or optical filters 248 are located in front of the detector 243 to eliminate all infrared light except the wavelength that the selected gas molecules can absorb. The detector 243 measures the amount of infrared (IR) light that was not absorbed by the filters 248. After passing through the sample gas chamber 240, the exhaust gas vapor exits the gas absorption cell through the exhaust port 245.

In an embodiment of the present invention, the passband or optical filters 248 are specific to sulfur dioxide.

In another embodiment of the present invention, the passband or optical filters 248 are specific to carbon dioxide, sulfur dioxide and water.

In yet another embodiment, the passband or optical filters 248 include four filters corresponding to a carbon dioxide filter, a carbon dioxide reference filter, a sulfur dioxide filter and a sulfur dioxide reference filter.

In another embodiment a relative humidity sensor 250 is present at the exhaust port 245 to measure the water vapor content of the exhaust gas.

In an alternate embodiment, the gas absorption cell 240 has a single IR light source 246 and the detector 243 includes two detectors corresponding to two different passband filters 248 for different gases in front of the two detectors, for example carbon dioxide and sulfur dioxide. Infrared light that is absorbed by a target gas (e.g. sulfur dioxide or carbon dioxide) passes through the active filter with a particular bandwidth for the detection of the target gas. Infrared light that does not interact with the target gas passes through the reference filter. The difference between transmitted light intensities in these two bandwidths is converted into gas concentration. A dual wavelength sensor ensures stable measurements for a long period of operation as the aging effects of the light source or the gas cell are automatically compensated by output signals at the reference wavelength.

The filter 248 for carbon dioxide is preferably 4.45 μm with a reference of 4.65 μm. The filter 248 for sulfur dioxide is preferably 7.3 μm, with a reference of 7.85 μm. The detection of water vapor content to use a background correction is 7.85 μm with a reference of 4.65 μm.

In another embodiment, more than one filter for carbon dioxide can be present and more than one filter for sulfur dioxide can be present.

In one embodiment, the filter 248 for carbon dioxide is between 1.9-2.1 μm. In another embodiment, the filter 248 for carbon dioxide is between 2.6-2.9 μm. In yet another embodiment, the filter 248 is between 4.1-4.5 μm.

In one embodiment, the filter 248 for sulfur dioxide is between 7.1-7.6 μm.

In one embodiment, other filters can be present with various bands which are non-overlapping with carbon dioxide and sulfur dioxide or other exhaust gases, for example between 1.3-1.5 μm, 1.75-2.0 μm, 2.5-3.0 μm, and 5.0-8.0 μm.

In one embodiment, reference bands can also be present as a filter 248 which +/−0.2 μm or less than the filter. For example, a reference filter can 3.09 μm, 3.72 μm, 3.95 μm, and/or 7.85 μm.

In yet another embodiment, the single IR light source 246 comprises multiple sources with the filters 248 being adjacent the emitter and the IR light source 246.

The gas concentration is sent by the one or more detectors to the processors of the electronic drivers and processors 18. Exhaust gas 52 is then pumped out the exhaust outlet of the emissions sampling apparatus 10.

Electronics Drivers/Processors

The processors 18 receive data associated with the exhaust gas in the stack from the gas absorption cell 240 and various sensors and sends the data associated with the gas and other data to the monitoring center 30 with the satellite modem 14. The data is preferably sent in a byte array to reduce the amount of data being sent. It is noted that the data from the emissions sampling apparatus 10 is sent to the monitoring system 30 in a regular periodic fashion whether or not it is able to communicate or spare the energy to run the communication channel, for example via the satellite modem 14.

If the satellite 26 is not available or the emissions sampling apparatus 10 does not have enough available energy to send the data, time stamped exhaust sample data is collected and stored in memory, such as one or more computer-readable RAMs 822 and one or more computer-readable ROMs 824 or one or more computer-readable tangible storage devices 830 to be uploaded at another time. The data can additionally be manually extracted from the emissions sampling apparatus 10 if necessary.

It should also be noted that the power management system 24 of the emissions sampling apparatus 10 prioritizes data collection. The power management system 24 reduces energy expenditure by stopping data transmission during low battery state.

An example of internal components associated with the electronic drivers and processors 18 are shown in FIG. 11. The electronic drivers and processors 18 can include one or more processors 820, one or more computer-readable RAMs 822 and one or more computer-readable ROMs 824 on one or more buses 826, and one or more operating systems 828 and one or more computer-readable tangible storage devices 830 as shown in FIG. 11. The one or more operating systems 828 are stored on one or more of the computer-readable tangible storage devices 830 for execution by one or more of the processors 820 via one or more of the RAMs 822 (which typically include cache memory). In the embodiment illustrated in FIG. 11, each of the computer-readable tangible storage devices 830 is a magnetic disk storage device of an internal hard drive. Alternatively, each of the computer-readable tangible storage devices 830 is a semiconductor storage device such as ROM 824, EPROM, flash memory or any other computer-readable tangible storage device that can store a computer program and digital information.

The internal components 800a also includes a R/W drive or interface 832 to read from and write to one or more portable computer-readable tangible storage devices present as part of the monitoring system 30.

The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire.

Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device.

Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language, and procedural programming languages, or similar programming languages. In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instructions by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention.

These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks.

The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks.

Sampling Data Collection

In an embodiment, data is collected from the exhaust gas at least every 60 minutes. The rate of collection can increase when the maritime vessel is less than 20 nautical miles from a monitoring SECA boundary.

FIG. 13 shows a sketch of a sample strategy as a ship crosses a SECA boundary (dash-dot line 120) from out at sea 121 to port 123 and back to sea 122. The inbound path of the ship is represented by dashed line 124, and the outbound path of the ship is represented by short-long dash line 125. Each arrow 126 on each of the paths 124 and 125 represents approximately an hour's sailing.

The circles 127a-127j along the paths 124 and 125 represent the point at which the system takes action, which will be explained in detail in the following description. The black-filled circles 127g-127h represent readings which are out of range or “bad” (i.e. noncompliant), while the open (white-filled) circles 127a-127f and 127j indicate readings which are within range (i.e. compliant). Circles with dotted lines show low-emissions readings, circles with solid lines show high-emissions readings.

The exemplary strategy proceeds as follows, with the numbers referring to points on FIG. 11:

- 127a—At this point, the ship is outside the SECA boundary 120 on the inbound path 124, so high sulfur fuel is permitted. The readings from the emissions sampling apparatus 10 would be high, but still compliant, since at this point the more restricted range of the SECA does not yet apply. The system takes readings on a selected schedule, for example every hour as shown on FIG. 11. More frequent or less frequent schedules could also be chosen as appropriate. When a reading is taken, the data from the reading—for example, time, location, compliance status, and perhaps raw sensor data numbers—are stored in a repository on the ship for later transmission to the monitoring center 30 on shore.
- 127b—The ship is approaching the SECA boundary 120. The system starts taking more frequent readings, perhaps every ten minutes or more frequently, so as to capture the data showing a switch from high sulfur fuel to low sulfur fuel.
- 127c—The ship switched to low sulfur fuel as required, and the system confirms this with readings which show emissions to be compliant.
- 127d—At this point the ship is within range of the shore-based mobile telephone network. The system connects to the network and transmits a status report to the server at least indicating that the onboard system is operating OK and the ship is compliant. If desired, a full upload of data from the onboard repository could be transmitted to the central server at this time.
- 127e—The ship is in port 123. The system continues to monitor emissions to make sure it remains compliant. If it did not do so in step 127d, the data in the repository can be uploaded to the monitoring center 30 at this time while the ship is in port.
- 127f—The ship has left port by outbound path 125. The readings show that the emissions remain compliant with the inside-SECA standards.
- 127g—The system has detected a sample with a “bad” or out-of-range reading. It is possible that the ship has changed over to high sulfur fuel too soon, outside the SECA boundary 120, or this might be a spurious reading caused by a bad sample or transient condition.
- 127h—The system takes more frequent readings for a period, in order to confirm that the sample actually shows an uncompliant status, and is not based on spurious readings. The readings continue to be out of range, so the system logs this as a noncompliant situation.
- 127j—Since the ship is outside the SECA boundary 120, the system would be applying the higher range. The readings taken by the system are once again “good”, indicating the ship is compliant with the standards applicable to this area.
- 127k—When the ship reaches its next port (off the map), all of the historical data accumulated since the last upload is transmitted from the onboard repository to the central server.

Alerts can be sent to a user on the ship with the emissions sampling apparatus 10 or an enforcement or government agency regarding compliance or non-compliance.

Mounting Options

FIGS. 8a-8f show examples of installation options for the shipboard emissions sampling apparatus 10. In FIGS. 8a-8d and 8f, there is a single funnel 140 within which there are multiple exhaust stacks 141, 143, 144, 145, and 146. FIG. 8e shows multiple funnels 147a and 147b of the sort shown in FIG. 8a. In each figure, locations 142 for installing the emissions sampling apparatus 10 are indicated by boxes.

FIGS. 8a and 8e show a front mounting option, and FIG. 8d shows a back mounting option. FIG. 8b shows an outboard side installation.

FIG. 8c shows a ship which has a curved exhaust stack 144 in addition to two straight pipes 141. For curved pipes 144, a side mount 142 as shown would be preferred.

FIG. 8f shows a cruise ship funnel 148 of the design where multiple exhaust stacks 149 leave the funnel 148 horizontally at the ends of “wings”.

Method of autonomous real-time sulfur dioxide and carbon dioxide monitoring

FIG. 7 shows a method of autonomous real-time sulfur dioxide and carbon dioxide monitoring of marine exhaust emissions.

In a first step, the monitoring system of the monitoring center 30 receives exhaust emissions analysis data and diagnostics data of the maritime vessel (step 901). The data may be sent in a data array to the monitoring system.

The exhaust emissions analysis data can include: date, time, latitude and longitude, sulfur dioxide values, carbon dioxide values, gas humidity, gas pressure, altitude of the emissions sampling apparatus 10, speed of the maritime vessel, and heading of the maritime vessel, fuel type being used and other information associated with the exhaust of the maritime vessel.

The latitude and longitude data, date, time, altitude, heading and speed of the maritime vessel can be supplied the GPS system 16.

The sulfur dioxide values and the carbon dioxide values are preferably raw detector values from the detector 243 behind the passband filters 248.

The gas pressure and gas temperature are preferably taken within the sample chamber 244 of the gas absorption cell 240 with sensors 251.

The gas humidity is supplied by the relative humidity sensor 250. The sulfur dioxide sensor values and carbon dioxide sensor values can be calculated by the electronic drivers and processors 18 from the readings provided by the gas absorption cell 240. The gas pressure can also be provided by the gas pressure/temperature sensor 36.

The diagnostic data can include: enclosure temperature or thermal data from a temperature sensor within the emissions sampling apparatus, battery voltage, TEG voltage, geolocation, sample gas conditioning, filter pressure present in the prefilter or the layered filter, and tamper detection count.

The enclosure temperature is taken by the internal gas pressure/temperature sensor within the emissions sampling apparatus to determine anomalies in the data may be caused by the environmental conditions that put the emissions sampling apparatus out of the thermal operating tolerances of emissions sampling apparatus.

The battery voltage and TEG voltage are measured using internal analog-to-digital (ADC) converters to monitor thermal energy harvesting effectiveness and battery capacity and degradation.