ISO-8861-1998.pdf

A Reference number ISO 8861:1998(E) INTERNATIONAL STANDARD ISO 8861 Second edition 1998-05-15 Shipbuilding Engine-room ventilation in diesel-engined ships Design requirements and basis of calculations Construction navale Ventilation du compartiment machines des navires à moteurs diesels Exigences de conception et bases de calcul ISO 8861:1998(E) © ISO 1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Genève 20 Switzerland Internetcentraliso.ch X.400c=ch; a=400net; p=iso; o=isocs; s=central Printed in Switzerland ii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non- governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 8861 was prepared by Technical Committee ISO/TC 8, Ships and marine technology, Subcommittee SC 3, Piping and machinery. This second edition cancels and replaces the first edition (ISO 8861:1988), of which it constitutes a technical revision. Annex A of this International Standard is for information only. INTERNATIONAL STANDARD © ISOISO 8861:1998(E) 1 Shipbuilding Engine-room ventilation in diesel-engined ships Design requirements and basis of calculations 1 Scope This International Standard specifies design requirements and suitable calculation methods for the ventilation of the engine room in diesel-engined ships, for normal conditions in all waters. Annex A provides guidance and good practice in the design of ventilation systems for ships' engine rooms. NOTE Users of this International Standard should note that, while observing the requirements of the standard, they should at the same time ensure compliance with such statutory requirements, rules and regulations as may be applicable to the individual ship concerned. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Interna- tional Standard are encouraged to investigate the possibility of applying the most recent editions of the standards listed below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 31-1:1992, Quantities and units Part 1: Space and time. ISO 31-3:1992, Quantities and units Part 3: Mechanics. ISO 31-4:1992, Quantities and units Part 4: Heat. ISO 3046-1:1995, Reciprocating internal combustion engines Performance Part 1: Standard reference conditions, declarations of power, fuel and lubricating oil consumptions, and test methods. ISO 3258:1976, Air distribution and air diffusion Vocabulary. 3 Definitions For the purposes of this International Standard, the definitions given below, together with those in ISO 31-1, ISO 31-3, ISO 31-4, ISO 3046-1 and ISO 3258, apply. 3.1 engine room: Space containing main propulsion machinery, boiler(s), diesel generator(s) and major electrical machinery, etc. -,-,- ISO 8861:1998(E) © ISO 2 3.2 ventilation: Provision of air to an enclosed space to meet the needs of the occupants and/or the requirements of the equipment therein. 3.3 service standard power: The continuous brake power which the engine manufacturer declares that an engine is capable of delivering, using only the essential dependent auxiliaries, between the normal maintenance intervals stated by the manufacturer and under the following conditions: a) at a stated speed at the ambient and operating conditions of the engine application; b) with the declared power adjusted or corrected as determined by the manufacturer to the stated ambient and operating conditions of the engine application; c)with the maintenance prescribed by the engine manufacturer being carried out. ISO 3046-1:1995 See A.1 in annex A of ISO 3046-1:1995. 4 Design conditions The outside ambient air temperature shall be taken as + 35 °C. Temperature rise from air intake to air passing from the engine room up to the casing entrance shall be max. 12,5 K. The capacity of the ventilation plant should be such as to provide comfortable working conditions in the engine room, to supply the necessary combustion air to the diesel engine(s) and boiler(s), and to prevent heat-sensitive apparatus from overheating. In order to meet these requirements, the air should be distributed to all parts of the engine room, so that pockets of stagnant hot air are avoided. Special considerations should be given to areas with great heat emission and to all normal working areas, where reasonably fresh and clean outdoor air should be provided through adjustable inlet devices. When arranging the air distribution, all normal conditions at sea and in harbour for in-service machinery shall be taken into account. 5 Airflow calculation 5.1 Total airflow The total airflow Q to the engine room shall be at least the larger value of the two following calculations. a:Q = qc + qh as calculated according to 5.2 and 5.3 respectively. b:Q = 1,5 x qc, i.e. the airflow for combustion + 50 %. The total airflow to the engine room shall not be less than the airflow for combustion engine(s) and boiler(s) plus 50 %. © ISOISO 8861:1998(E) 3 Combustion air to, and heat emission from, all equipment installed within the casing and funnel shall not be taken into account. The calculations shall be based on simultaneous maximum rating of main propulsion diesel engine(s), diesel generator engine(s), boiler(s) and other machinery under normal sea conditions, and on a temperature increase of 12,5 K. The calculations should, to the greatest possible extent, be based on information from the manufacturers. Guidance values given in this International Standard should be used only when manufacturers' information is not available. In order to ensure satisfactory air distribution, combustion air to, and heat emission from, main propulsion diesel engine(s), diesel generator engine(s), generator(s), boiler(s), and possibly other machinery with considerable heat emission, shall be calculated separately including other conditions as necessary. Spaces separated from the main engine room, such as individual auxiliary engine rooms, boiler rooms and separator rooms, shall also be calculated separately. 5.2 Airflow for combustion 5.2.1 Sum of airflow for combustion The sum of the airflow for combustion, qc, shall be calculated, in cubic metres per second, as follows: qc = qdp + qdg + qb where qdpis the airflow for combustion for main propulsion diesel engine(s), in cubic metres per second (see 5.2.2); qdgis the airflow for combustion for diesel generator engine(s), in cubic metres per second (see 5.2.3); qbis the airflow for combustion for boiler(s), in cubic metres per second (see 5.2.4), if relevant under normal sea conditions. 5.2.2 Airflow for combustion for main propulsion diesel engine(s) The airflow for combustion for the main propulsion diesel engine(s), qdp, shall be calculated, in cubic metres per second, as follows: dp dpad = q Pm × r -,-,- ISO 8861:1998(E) © ISO 4 where Pdpis the service standard power of the main propulsion diesel engine(s) at maximum continuous power output, in kilowatts; madis the air requirement for combustion for diesel engine(s), in kilograms per kilowatt second; NOTE Where specific data for mad are not available, the following values may be used for calculation: mad=0,002 3 kg/(kWs) for 2-stroke engines, 0,002 0 kg/(kWs) for 4-stroke engines. r = 1,13 kg/m3 (i.e. the density of air, at + 35 °C, 70 RH and 101,3 kPa). 5.2.3 Airflow for combustion for diesel generator engine(s) The airflow for combustion for diesel generator engine(s), qdg, shall be calculated, in cubic metres per second, as follows: dg dgad = q Pm × r where Pdgis the service standard power of the diesel generator engine(s) at maximum power output, in kilowatts; madis the air requirement for diesel engine combustion, in kilograms per kilowatt second; NOTE Where specific data for mad are not available, the following values may be used for calculation: mad=0,002 3 kg/(kWs) for 2-stroke engines, 0,002 0 kg/(kWs) for 4-stroke engines. r = 1,13 kg/m3 (i.e. the density of air, at + 35 °C, 70 % RH and 101,3 kPa). 5.2.4 Airflow for combustion for boilers and thermal fluid heaters The airflow for combustion for boiler(s), qb, shall be calculated, in cubic metres per second, as follows: In a case where the total steam capacity of a boiler is known, the following formula is used: -,-,- © ISOISO 8861:1998(E) 5 b sfsaf q mmm = ×× r In a case where the capacity of a boiler or a thermal fluid heater is known in kilowatts, the following formula is used: b fsaf = q Qmm×× r where Qis the maximum continuous rating of the boiler(s), in kilowatts; msis the total steam capacity (maximum continuous rating) of the boiler(s), in kilograms per second; mfsis the fuel consumption, in kilograms of fuel per kilogram of steam, or in kilograms of fuel per second per kilowatt of thermal capacity; NOTE Where specific data are not available, mfs = 0,077 kg/kg may be used for the calculation if the steam capacity is known. If the thermal capacity is known, mfs = 0,11 kg s-1 kW-1 may be used. mafis the air requirement for combustion, in kilograms of air per kilogram of fuel; NOTE Where specific data are not available, maf = 15,7 kg/kg may be used for calculation. r = 1,13 kg/m3 (i.e. the density of air, at + 35 °C, 70 % RH and 101,3 kPa). 5.3 Airflow for evacuation of heat emission The sum of the airflow necessary for heat evacuation, qh, shall be calculated, in cubic metres per second, as follows: q cT qqq hdpdgb = 0,4 (+) dpdgbpgelepto fffffffff+ ×× rD where fdpis the heat emission from main propulsion diesel engine(s), in kilowatts (see 6.1); fdgis the heat emission from diesel generator engine(s), in kilowatts (see 6.2); fbis the heat emission from boilers and thermal fluid heaters, in kilowatts (see 6.3); fpis the heat emission from steam and condensate pipes, in kilowatts (see 6.4); -,-,- ISO 8861:1998(E) © ISO 6 fgis the heat emission from electrical air-cooled generator(s), in kilowatts (see 6.5); felis the heat emission from electrical installations, in kilowatts (see 6.6); fepis the heat emission from exhaust pipes including exhaust gas-fired boilers, in kilowatts (see 6.7); ftis the heat emission from hot tanks, in kilowatts (see 6.8); fois the heat emission from other components, in kilowatts (see 6.9); qdpis the airflow for main propulsion diesel engine combustion, in cubic metres per second (see 5.2.2); qdgis the airflow for diesel generator engine combustion, in cubic metres per second (see 5.2.3); qbis the airflow for boiler combustion, in cubic metres per second (see 5.2.4); r = 1,13 kg/m3 (i.e. the density of air, at + 35 °C, 70 % RH and 101,3 kPa); c =1,01 kJ/(kgK) (the specific heat capacity of the air); T = 12,5 K (the increase of the air temperature in the engine room i.e. the difference between inlet and outlet temperature measured at design conditions. The outlet temperature shall be measured at the outlet from engine room to casing or funnel without heat-sensitive installations). The factor 0,4 is based on the usual arrangements of engine room and ventilation ducts. In a case of special arrangements, the value of the factor should be considered. 6 Calculation of heat emission 6.1 Heat emission from main propulsion diesel engine(s) The heat emission from main propulsion diesel engine(s), fdp, shall be taken, in kilowatts, as follows: fdp dp d = 100 P h × D where Pdpis the service standard power of the main propulsion diesel engine(s) at maximum continuous rating, in kilowatts; hdis the heat loss from the diesel engine(s), in percentage. -,-,- © ISOISO 8861:1998(E) 7 NOTE Where specific data are not available, fdp according to 7.1 may be used for calculation. 6.2 Heat emission from diesel generator engine(s) The heat emission from diesel generator engine(s), fdg, shall be taken, in kilowatts, as follows: fdg dg d = 100 P h × D where Pdgis the service standard power of the diesel generator engine(s) at maximum continuous rating, in kilowatts; Stand-by units are not to be included. hdis the heat loss from the diesel engine(s), in percentage. NOTE Where specific data are not available, fdg according to 7.1 may be used for calculation. 6.3 Heat emission from boiler(s) and thermal fluid heater(s) NOTE For heat emission from exhaust gas-fired boiler(s) and exhaust pipes see 6.7. The heat emission from boiler(s) and thermal fluid heater(s), fb, shall be calculated, in kilowatts, as follows: In the case when the total steam capacity of a boiler is known, the following formula is used: fb sfs b = 100 mmh h B×××× D 1 In the case when the demand for heat is covered by a thermal fluid heater or the capacity of a boiler is known in kilowatts, the following formula is used: fb 1 b = 100 QB h ×× D where msis the total steam capacity, in kilograms per second; mfsis the fuel consumption, in kilograms of fuel per kilogram of steam; NOTE Where specific data are not available, mfs = 0,077 kg/kg may be used for calculation. ISO 8861:1998(E) © ISO 8 his the lower calorific value of the fuel, in kilojoules per kilogram; NOTE Where specific data are not available, h = 40,200 kJ/kg may be used for calculation. hbis the heat loss, in percentage, at the maximum continuous rating of the boiler or thermal fluid heater; NOTE Where specific data are not available, data according to 7.2 may be used for calculation. B1is a constant that applies to the location of the boiler(s) and other heat exchangers in the engine room (refer to text in 6.7 for value of B1); Qis the maximum continuous rating of the thermal fluid heater or boiler in kilowat