Real time ship exhaust gas monitoring for compliance to SOx and NOx regulation and CO2 footprint

Abstract

IMO MARPOL Annex VI regulation has been set for global application to reduce the negative consequences of ship gas emissions SOx, NOx, and CO2. To enforce the regulation, real time gas emission monitoring system is in need. The system in this paper consists of a microcontroller, gas analyzers, sensors and Iridium radio module. The data acquired from the sensors and gas analyzer is transmitted using a microcontroller over the Iridium satellite to the ground station for real-time compliance check. Real time monitoring system expedites the checks by the ground station in enforcing the regulation. Ultimately, this application enables engine manufacturers, ship-owners and Administrations to ensure in real time that all applicable marine diesel engines are in compliance with the limiting values determined by IMO MARPOL Annex VI. Figure 1. SOx, NOx, and CO2 emission limit (continued) This paper offers the solution of the lack of technology mentioned above. The illustration of this solution can be found in the Figure 2 below. Important parameters for compliance are measured by sensors that give electrical signal output of various types. After that, the data value from the sensors is collected by the microcontroller (data acquisition system). The microcontroller processes the data calculation and output the value useful for end-user such as SOx,NOx and CO2 emission. This end-user data is stored in the local memory of the microcontroller. Thereafter, the end-user data is transmitted through the Iridium satellite, from the location of the marine diesel engine being monitored to the any place on earth. In this case, the ground station (headquarter in Figure 2.) of the country shall get the data for law enforcement. This end-user data obtained by the ground station is then stored and used accordingly for monitoring purposes. Ultimately, the aim of this solution is to be the standard for IMO to enforce the IMO MARPOL Annex VI. Figure 2. Overview of the System 2 PARAMETERS MEASUREMENT The parameters required for compliance refer to the independent variables identified in the 2009 Guidelines for Exhaust Gas Cleaning Systems, and Chapter 6.4 Direct Measurement and Monitoring Method of the NOx Technical Code (2008). These independent parameters are listed in Table 1 as follows. Table 1. Independent parameters for compliance calculation ___________________________________________________ Symbol Term Unit ___________________________________________________ qmaw Intake air mass flow rate on wet basis ^ kg/h qmad Intake air mass flow rate on dry basis ^ kg/h qmf Fuel mass flow rate ^ kg/h cSO2d Concentration of SO2 in the exhaust in ppm dry basis ^ cNOd Concentration of NO in the exhaust gas in dry basis ^ ppm cNO2d Concentration of NO2 in the exhaust gas in dry basis ^ ppm cCO2d Concentration of CO2 in the exhaust gas in dry basis ^ ppm and (%V/V) cCOd Concentration of CO in the exhaust gas in dry basis ^ ppm pb Total barometric pressure ^ kPa Ra Relative humidity of the intake air ^ % Ta Intake air temperature determined at the engine intake ^ K TSC Charge air temperature ^ K PAHw Polycyclic Aromatic Hydrocarbon concentration of wash water ^ μg/L PAHphe Turbidityw Turbidity of the wash water ^ FNU or NTU pHw pH of the wash water ^ 1 Tw Temperature of the wash water ^ K Paux Declared total power absorbed by auxiliaries fitted for the test and not required by ISO14396 * kW Pm Maximum measured or declared power at the test engine speed under test condition * kW WALF H content of fuel * % m/m WBET C content of fuel * % m/m TSCRef Charge air reference temperature * K WF Weighting factor ** 1 u Ratio of exhaust component and exhaust gas densities ** 1 Tb Temperature of water vapor after cooling bath of the analysis system ** o C ________________________________________________ ^ Require sensor or gas analyzer to measure * Obtained from the manufacturers Technical File ** Obtained from NOx Technical Code (2008) The parameters above will be used for calculation using the following formulas below which are adjusted specifically for incomplete combustion and compression ignition engines with intermediate air cooler. Calculating gasx in equation (1) is our goal.