Calculation method of fire cooling water quantity

The calculation method of fire cooling water quantity of oil terminals in the code for fire protection design of oil loading and unloading terminals (JTJ), the fire cooling water quantity of oil terminals is specified in detail, and the calculation formula of cooling range is proposed, but several parameters in the formula, especially the determination method of the maximum longitudinal length and maximum tank area of oil tankers, are not specified. After analysis, the author gives the calculation method of these two parameters for reference

1 fire fighting cooling water volume

the cooling water volume is directly related to the cooling range. Article 6.2.7.1 of JTJ stipulates that the cooling range is:

f=3lb fmax

where: F cooling range (M2)

b maximum ship width (m)

l longitudinal length of the maximum cabin (m)

fmax maximum cabin area (M2)

among the three elements B, l and Fmax in the calculation formula, B can generally be queried, but the data of L and Fmax are difficult to be queried. The data of L and Fmax often change with the amount of data the designers master, often with blindness and randomness. Therefore, the calculated value of fire cooling water may vary from person to person, and the data vary greatly. It is hoped that the L and Fmax reference data of each tonnage oil tanker should be listed in the specification for the reference of designers and fire audit departments. To ensure the standardization and identity of fire protection design for oil terminals of the same grade and specification. For this purpose, the author tries to find out a rule that can be roughly followed by the fire cooling water volume of the oil terminal. For example, the specification classification of the berthing oil tanker shall be in accordance with the specifications of the oil tanker listed in the appendix of the code for general layout design of seaports (JTJ), as shown in Table 1

now the cooling range of each tonnage oil tanker is calculated according to the standard of class a oil terminal

length limit of cargo oil tanks of oil tankers according to the cargo oil tank length limit provisions in article 6.7.5.2 of the practical manual for ship design, maprol requires that the length of each cargo oil tank shall not be greater than 10m or the value in table 6.7.5.2 of the manual (Table 2), whichever is greater

side tank width Bi, according to the regulations of Annex I of 13F of MARPOL (73/78 International Convention for the prevention of marine pollution), the side tank bi=0.5+dw/20000 or 2.0m (whichever is smaller), and the minimum value is 1.0m. The fire-fighting design parameters of oil tankers are listed accordingly (the tonnage of oil tankers is calculated according to the tonnage of first-class wharf ships =20000dwt in article 3.0.2 of the new code). See Table 3

2 cooling range

the cooling area shall be calculated and determined according to the calculation formula of cooling range in article 6.2.7.1 of JTJ. Article 6.5.6 at least one fire-fighting ship or dual-purpose fire-fighting and towing ship shall be arranged at the first-class wharf for loading and unloading class a oil products. The total flow of fire monitor of each fire boat shall not be less than 100l/s. The cooling water for the fire compartment of the oil tanker can be jointly provided by the water and land fire fighting equipment, but the cooling water provided by the land fire fighting equipment shall not be less than 50% of the total cooling water. According to the provisions of JTJ, the minimum supply intensity of fire cooling water for oil tankers loading and unloading class a oil products at class I wharf can be obtained, as shown in Table 4

the layout of fire water monitor in oil wharf shall cool the deck of oil tank in a certain range around the fire oil tank. That is, the spraying range of the fire water monitor should be able to cover the whole oil tanker. Under certain working pressure, the cooling water spraying intensity and range of the fire water monitor are a pair of mutually restrictive parameters, which serve the major well-known brand manufacturers in the medical, pharmaceutical, personal care, household and other industrial and food and beverage markets, such as 29.42. The spraying water volume is large and the range is long. Therefore, When selecting the fire water monitor, it shall be checked whether the spray water volume can meet the cooling water intensity requirements for extinguishing the fire of the oil tank, and whether the range of the fire water monitor can extinguish the range of the whole oil tanker. The number of fire monitors in the oil terminal shall be as few as possible. Although plastics also include composite materials, the impact of fire monitor devices on loading and unloading operations shall be minimized. Sometimes, affected by the fire monitor product series, the fire monitor with large flow and long range is currently vacant. Therefore, the fire monitor with relatively small flow can also be selected on the oil wharf, and doors can be arranged. Every two fire monitors can jointly extinguish the fire in the fire oil tank