By purpose, ships are distinguished for the transportation of frozen products (meat, fish) at a temperature of -12 to -25 ° C, refrigerated perishable goods and fruits (bananas, fruits, canned food) at a temperature of +14 to -5 ° C and universal ships with refrigerated holds, adapted to maintain the temperature in the holds from +14 to -25 °C.
Refrigerated transport vessels are multi-deck shelter-deck type with excess freeboard and high specific cargo capacity. Based on the condition of the allowable stacking height and to ensure good ventilation of the cargo, the height of the cargo spaces usually does not exceed 3-4 m, and when transporting bananas, wooden lattice platforms (greyingdecks) are additionally installed, dividing the hold into rooms with a height of about 2 m. In addition, when transporting bananas, bananas, cargo spaces are divided by wooden bars into cells (bins) with a volume of 15-20 m 3 each. The special equipment of vessels for the transportation of perishable goods consists of refrigeration units, insulation of cargo spaces, cooling systems, ventilation and ozonation. Basic requirements for insulation: heat resistance throughout the life of the vessel, fire resistance, hygiene, lightness, resistance to decay and mold. Holds are insulated with sheets of plywood, aluminum-magnesium alloys, galvanized iron or internit. On the decks, a flooring of slats or bars is arranged to allow the flow of cold air under the load.
The cooling system of cargo spaces is air or air-brine. Freon-12, freon-22 (to obtain low temperatures) or ammonia are used as a refrigerant. The forced ventilation system should also be referred to the special systems of refrigerated ships. By means of ventilation on these ships, the cold received from the air coolers is transferred to the cargo being transported, odors and harmful gases are removed from the cargo spaces and proper humidity, carbon dioxide and oxygen levels are maintained. Multiplicity of circulation (replacement of air with fresh outside): 1.5-2.5 rpm. Ventilation systems: horizontal, vertical and combined.
Refrigeration units, insulation, cooling systems reduce the cargo capacity of refrigerated ships by about 20%. To reduce air access during loading and better insulation of cargo spaces, they are equipped with central hatches with sectional closures. Arrows or cranes with a lifting capacity of 3-5 tons are used as cargo equipment. To carry out cargo operations in any weather and outdoor temperature, onboard lap ports are arranged, and cargo is moved between decks by elevators.
Since perishable cargo is transported, as a rule, only in one direction and it is seasonal, refrigerated ships are often used to transport ordinary general cargo, primarily valuable, requiring urgent delivery. It is not allowed to transport goods in refrigerated rooms that stain or leave a peculiar smell, as well as heavy loads that can damage the insulation and the cooling system. To fully utilize the carrying capacity for general cargo transportation, modern refrigerated ships are built as full-set with a tonnage mark or as ships with an open-closed shelter deck.
The size of refrigerated ships is determined by the size of ship shipments of perishable goods in each specific direction, the distance of transportation, the presence of port refrigerators and ranges from 3-5 to 15-20 thousand m 3 and more. Combined ships are often built, in which some cargo spaces are refrigerated, while others are designed for ordinary general cargo. To ensure the safety and reduce the delivery time of expensive goods, refrigerated ships usually have an increased speed of 18-22 knots.
Perishable goods can be transported in standard refrigerated containers on container ships, which makes it possible to dramatically increase the standards of cargo handling, simplify the design and equipment of the ship. Some of these ships are being built as cellular container ships or as ro-ro ships.
Objective:
Familiarization with the existing types of refrigerated ships and with the main requirements of the register for CFS.
Theoretical part:
By purpose, refrigerated vessels of the fishing industry fleet can be divided into three main groups: mining, processing and receiving and transport. The classification scheme for refrigerated ships is shown in Fig. 1.
Rice. 1. Classification scheme for refrigerated ships.
Mining refrigerated vessels are designed for catching fish and primary or complete processing of the extracted raw materials. Vessels of this group can be subdivided into the following subgroups:
1. Small and medium-sized refrigerated fishing trawlers (MRTR, SRTP and RTR). These small to medium displacement vessels have refrigeration units for ice making and hold cooling, which store chilled fish for a short period of time before being transferred to processing vessels.
2. Medium fishing trawlers (freezing) SRTM. This subgroup of vessels is close in its characteristics to the previous one, but differs from it in that these vessels freeze and store fish before handing it over to transport refrigerators. Vessels of this type are equipped with cabinet or plate freezers, and the storage of frozen products is carried out in refrigerated holds. Frozen products from these vessels are transferred to transport refrigerators.
3. Large-tonnage fishing trawlers. This group includes vessels of the BMRT types (with a displacement of 3,500 to 6,500 tons); RTM (from 2400 to 8000 tons); PPR (5500-5700 t); BKRT (about 10,000). These vessels are designed to catch, freeze and process fish (for canned food), fish waste and non-food fish (for fishmeal). Vessels of this type are equipped with freezers and have refrigerated holds, which make it possible to store a large amount of frozen fish products before delivery to transport refrigerators.
Most of the vessels of this group are floating fish processing bases: herring and universal. Herring bases are used for processing herring and other types of fish sent for salting and making preserves. A feature of these vessels is the relatively high storage temperature in the holds (about ─2º C). Universal fish processing bases, in addition to salting equipment, have mechanized lines for the production of preserves, canned food, fat-and-fat plants, powerful freezers, ice makers and other equipment.
Receiving and transport refrigerated vessels are designed to receive canned fish products at sea and deliver them to ports of destination. These vessels do not have refrigeration and freezing facilities, but the capacity of the refrigeration equipment makes it possible to slightly lower the temperature in the holds. The current trend in the development of the receiving and transport fleet is based on the use of large-capacity high-speed vessels with a carrying capacity of 5-7 thousand tons or more. Modern transport refrigerators are equipped with powerful refrigeration units with a universal or low-temperature mode of holds.
Processing vessels accept raw fish or semi-finished products from harvesting vessels and process them (freezing, filleting, salting, making preserves, etc.). The received products are transferred to transport refrigerators and transported to the port in the holds of processing vessels. Processing vessels include: fish processing bases; industrial refrigerators used to freeze raw materials received from mining vessels; whaling, tuna and fish-meal bases, as well as other ships processing raw materials of various kinds.
The design of refrigerated ships, including refrigeration units, is carried out in two stages: the development of technical and working projects. The development of a technical project is preceded by the development of a design task (based on the study of fleet development trends, the location of production forces, the dynamics of changes in the fishing base), as well as draft studies of the designed vessels.
With regard to the refrigeration plant of a refrigerated vessel, based on the feasibility study, the performance of technological devices is set and the estimated refrigeration capacity of machines serving various systems (freezing complex, hold cooling systems, pre-cooling, air conditioning system, etc.) is determined. The design process also determines the type of refrigerant, the types of refrigeration machines used, freezers and other devices that use cold, a rational cooling scheme, types of insulating enclosures, integrated mechanization and automation systems for refrigeration plants.
At the same time, it is worth considering the features of the operation of CFS intended for various purposes. When designing CFS, it is necessary to take into account a number of requirements determined by the Rules of the Register of Russia:
1. SCS must have increased reliability in specific rolling conditions, with trim and roll, with shocks, shocks, and also with hull vibration;
2. When determining the refrigeration capacity of the installation, the conditions for redundant machines and apparatuses to ensure the specified temperature regime of the apparatus must be taken into account to ensure the specified temperature regime in refrigerated premises during continuous operation for at least 24 hours with any unit of the installation turned off. At the same time, sources of electricity should also be reserved;
3. CFS must be equipped with devices for automatic protection and regulation of the main parameters, as well as the necessary safety devices in case of emergencies.
The layout of the refrigeration unit in the ship's hull causes certain difficulties associated with the limited dimensions of the premises. The dimensions of the premises, as well as the weight of the equipment, affect the carrying capacity and, as a result, the overall economic efficiency of the refrigerated vessel and its displacement, which determine the general location of the engine rooms, production and residential premises, as well as the refrigerated premises.
On refrigerated ships, from one to three, and sometimes up to four cold consumers are used, which serve the corresponding refrigerating machines at different boiling temperatures of the refrigerant. Each of the groups of refrigeration machines can serve several consumers: a freezing complex, refrigerated holds, ice generators, etc. Groups of refrigeration units with a higher boiling point (0-10) serve the air conditioning system. The refrigeration capacity of each of the groups of refrigeration machines is determined by calculating the corresponding consumer system, based on the given initial data.
The volume of the premises of machine and technological rooms is found by design studies in relation to a certain type of refrigeration machines and technological equipment, taking into account the restrictions under the Rules of the Register of Russia.
Layout of ship refrigeration plants.
Layout of engine rooms, technological rooms and refrigerated cargo compartments:
The distribution of masses over the ship's hull must be uniform. Stability, heel, trim and other parameters that ensure the safety of navigation must comply with the standards established for this class of vessel;
The possibility of installation, repair and operation of equipment in compliance with safety regulations, the minimum length of unloading lines, as well as the convenience of loading and unloading operations using mechanization should be provided;
Cooled rooms should border one another and form common blocks with a minimum temperature difference between them, which can significantly reduce external heat gains;
With various storage modes in interconnected holds and tween decks, a lower temperature is maintained in the hold, and a higher temperature is maintained in the tween deck.
In accordance with the Rules of the Register of Russia, the premises of ammonia refrigeration machines must be gas-tight and isolated from other premises. Freon machines do not need to be installed in isolated gas-tight spaces, if necessary, they can be installed in the main engine room. The refrigerating machine rooms should have two exits as far apart as possible, with doors opening outwards, one of the exits leading to the open deck.
The premises of freon automated refrigeration machines, where a permanent watch is not provided, may not have a second exit. Exits from the premises of ammonia machines should have devices for creating a water curtain, and it is recommended that the premises themselves be equipped with a dehumidification system. The premises of refrigeration machines must be equipped with systems of main and emergency ventilation, ventilation must have a tenfold air exchange per hour for natural and twenty times for artificial. Emergency ventilation should provide forty-fold air exchange for ammonia machines and twenty-fold for freon machines.
Refrigeration machines are recommended to be placed in separate enclosed rooms, which can be located both at the level of the main engine room and at higher levels. In particular, the premises of refrigeration machines can be located under the spardeck or in special above-deck wheelhouses. In the latter case, free access to the open deck is facilitated and the ventilation system is simplified. Small automatic freon refrigerating machines for provision chambers are installed in the immediate vicinity of them in special enclosures. Refrigerant storage areas should be separate from other areas, properly ventilated, and fenced off to be fire resistant. Refrigerant cylinders must be securely fastened using non-metallic gaskets, and the temperature in rooms with refrigerant cylinders must not exceed 45°C.
For example, Fig. 2 shows the layout of the BMRT (project 394), on which the MXM-240 refrigerating machine with a cooling capacity of 279 kW (240,000 kcal / h) with three DAU-80 compressors is installed. the refrigerating machine is located amidships on the starboard side in a separate enclosed space near the engine room. The refrigerating machine serves the freezing complex, which consists of two tunnel-carry freezers, as well as three refrigerated holds, two of which are located in the bow of the vessel, and one is in the stern.
In accordance with the requirements of the Register of Russia, the holds are cooled using a brine cooling system, and the required temperature in freezers is maintained using direct-cooling air coolers.
Figure 3 shows a longitudinal section of the fish processing base (project B-69), on which an ammonia refrigeration unit is installed, serving the freezing complex, refrigerated holds, pre-cooling system, ice generators, air conditioning system and technological cold consumers. The main data of the refrigeration unit are given in.
Refrigerator compartment on the main deck, in the bow of the ship, above the refrigerated holds No. 1 and No. 2. The fish processing factory, which includes a freezing complex and processing lines for processing fish, is located on the same deck in the middle part of the ship.
Fig.3. Project 394 BMRT layout:
a - longitudinal section: 1-cargo hold No. 1 with a capacity of 350 m³; 2-cargo hold No. 2 with a capacity of 750 m³; 3-room of refrigeration machines; 4-cargo hold No. 3 with a capacity of 415 m³; 5-fish meal hold with a capacity of 150 m³; 6-room of the fish shop:
b - plan of the upper deck; 1-canning compartment; 2-room of the fish shop; 3 freezers; 4-corridor of refrigeration pipelines and belt conveyor; 5-room fish meal plant.
Fig. 4. Longitudinal section of the fish processing base of the B-69 project:
1 - refrigerated engine room; 2 - cooled holds; 3 - cooled tween decks; 4 - fish meal plant; 5 - power plant; 6 - main engine room; 7 - boiler room; 8 - the premises of the fish processing factory.
Fig. 5. Longitudinal section of a transport refrigerator of the Russian Island type:
1 - refrigerated engine room; 2 - cooled holds; 3 - cooled tween decks; 4 - main engine room.
The relative location of the chiller and cold consumers is chosen in such a way as to ensure the minimum length of pipelines for the refrigerant and coolants.
The holds are cooled by batteries using a brine cooling system.
Figure 4 shows a longitudinal section of a transport refrigerator of the Russian Island type, equipped with a freon (freon-22) refrigeration unit with single-stage compressors. The refrigerator compartment is located on the upper deck, in its middle part, in a fenced-off room. This makes it possible to minimize the length of the freon pipelines supplying the refrigerant to the direct-cooling air coolers located in special rooms inside the isolated circuit of the cooled holds and tweendecks. Four of the five refrigerating machines (one of them is a reserve) serve four sections of the refrigerated spaces, each of which includes one hold and a tween deck located above it.
Basic data of various ship refrigeration units are given in.
1. Konstantinov L.I., Melnichenko L.G. Ship refrigeration units. - M.: Food industry, 1978.
2. Konstantinov L.I., Melnichenko L.G. Calculations of refrigeration machines and installations. - M .: Agropromizdat, 1991.
By purpose, ships are distinguished for the transportation of frozen products (meat, fish) at a temperature of -12 to -25 ° C, refrigerated perishable goods and fruits (bananas, fruits, canned food) at a temperature of +14 to -5 ° C and universal ships with refrigerated holds, adapted to maintain the temperature in the holds from +14 to -25 °C.
Refrigerated transport vessels are multi-deck shelter-deck type with excess freeboard and high specific cargo capacity. Based on the condition of the allowable stacking height and to ensure good ventilation of the cargo, the height of the cargo spaces usually does not exceed 3-4 m, and when transporting bananas, wooden lattice platforms (greyingdecks) are additionally installed, dividing the hold into rooms with a height of about 2 m. In addition, when transporting bananas, bananas, cargo spaces are divided by wooden bars into cells (bins) with a volume of 15-20 m 3 each. The special equipment of vessels for the transportation of perishable goods consists of refrigeration units, insulation of cargo spaces, cooling systems, ventilation and ozonation. Basic requirements for insulation: heat resistance throughout the life of the vessel, fire resistance, hygiene, lightness, resistance to decay and mold. Holds are insulated with sheets of plywood, aluminum-magnesium alloys, galvanized iron or internit. On the decks, a flooring of slats or bars is arranged to allow the flow of cold air under the load.
The cooling system of cargo spaces is air or air-brine. Freon-12, freon-22 (to obtain low temperatures) or ammonia are used as a refrigerant. The forced ventilation system should also be referred to the special systems of refrigerated ships. By means of ventilation on these ships, the cold received from the air coolers is transferred to the cargo being transported, odors and harmful gases are removed from the cargo spaces and proper humidity, carbon dioxide and oxygen levels are maintained. Multiplicity of circulation (replacement of air with fresh outside): 1.5-2.5 rpm. Ventilation systems: horizontal, vertical and combined.
Refrigeration units, insulation, cooling systems reduce the cargo capacity of refrigerated ships by about 20%. To reduce air access during loading and better insulation of cargo spaces, they are equipped with central hatches with sectional closures. Arrows or cranes with a lifting capacity of 3-5 tons are used as cargo equipment. To carry out cargo operations in any weather and outdoor temperature, onboard lap ports are arranged, and cargo is moved between decks by elevators.
Since perishable cargo is transported, as a rule, only in one direction and it is seasonal, refrigerated ships are often used to transport ordinary general cargo, primarily valuable, requiring urgent delivery. It is not allowed to transport goods in refrigerated rooms that stain or leave a peculiar smell, as well as heavy loads that can damage the insulation and the cooling system. To fully utilize the carrying capacity for general cargo transportation, modern refrigerated ships are built as full-set with a tonnage mark or as ships with an open-closed shelter deck.
The size of refrigerated ships is determined by the size of ship shipments of perishable goods in each specific direction, the distance of transportation, the presence of port refrigerators and ranges from 3-5 to 15-20 thousand m 3 and more. Combined ships are often built, in which some cargo spaces are refrigerated, while others are designed for ordinary general cargo. To ensure the safety and reduce the delivery time of expensive goods, refrigerated ships usually have an increased speed of 18-22 knots.
Perishable goods can be transported in standard refrigerated containers on container ships, which makes it possible to dramatically increase the standards of cargo handling, simplify the design and equipment of the ship. Some of these ships are being built as cellular container ships or as ro-ro ships.
The Russian fleet includes refrigerated ships of a universal type built in the Soviet years (Nicholas Copernicus, Alexandra Kollontai series). The deadweight of a vessel of the Nicolaus Copernicus type is 5500/3750 tons, depending on the draft, and the carrying capacity of the holds is 7450 m 3 . The vessel has two continuous steel decks and two grating decks. Decks and transverse bulkheads divide the cargo spaces into eight independent chambers, in each measurement it is possible to maintain a temperature from +15 to
20 °C. Vessel speed in cargo 18-20 knots.
refrigerated ship- cargo vessel specially built, equipped refrigeration units for the transport of perishable goods. Depending on the temperature regimes of cargo spaces, refrigerated ships are divided into low-temperature, designed for the transport of frozen cargo, universal - for the transport of any cargo, as well as fruit carriers - ships with enhanced ventilation of the premises, adapted for the transport of fruits. Refrigerated ships are usually multi-deck, with a small (2.3 - 2.5) height of inter-deck spaces and small hatches to reduce cold losses during cargo operations. The cargo device is a boom, less often a crane. All cargo spaces are thermally insulated.
There are 1,100 refrigerated ships in the world at the beginning of the 2000s.
Refrigerated hold
Refrigerated hold - cargo space on ship, which allows the transportation of goods that require storage under certain temperature and ventilation conditions under the conditions of transportation.
To this end, the refrigerator hold equipped thermal insulation, ventilation system and refrigeration unit, and the cover of the hold is made relatively small - to reduce heat loss.
Story
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Notes
Literature
- Isanin, Nikolai Nikitich. Marine encyclopedic reference book. - L .: Shipbuilding, 1987. - T. 2. - S. 182. - 524 p. - 30,000 copies.
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An excerpt characterizing the Refrigerated ship
To my great regret, I was able to do this only after my father's death, after many, many years ...Their grandfather's sister Alexandra Obolenskaya (later - Alexis Obolensky) was also exiled with them, and Vasily and Anna Seregins, who voluntarily went, followed their grandfather by their own choice, since Vasily Nikandrovich for many years was grandfather's attorney in all his affairs and one of the most his close friends.
Alexandra (Alexis) Obolenskaya Vasily and Anna Seryogin
Probably, one had to be a truly FRIEND in order to find the strength in oneself to make such a choice and go of one's own free will to where one was going, as one goes only to one's own death. And this "death", unfortunately, was then called Siberia ...
I was always very sad and hurt for our, so proud, but so mercilessly trampled by Bolshevik boots, beautiful Siberia! ... And no words can tell how much suffering, pain, lives and tears this proud, but exhausted to the limit, land absorbed ... Is it because it was once the heart of our ancestral homeland, "far-sighted revolutionaries" decided to denigrate and destroy this land, choosing it for their diabolical purposes?... After all, for many people, even after many years, Siberia still remained a "cursed" land, where someone's father died, someone's brother, someone then the son ... or maybe even someone's whole family.
My grandmother, whom I, to my great chagrin, never knew, at that time was pregnant with my father and endured the road very hard. But, of course, there was no need to wait for help from anywhere ... So the young Princess Elena, instead of the quiet rustle of books in the family library or the usual sounds of the piano when she played her favorite works, this time listened only to the ominous sound of wheels, which, as it were menacingly they were counting the remaining hours of her life, so fragile and turned into a real nightmare... She was sitting on some sacks at the dirty car window and staring at the last pitiful traces of the "civilization" so familiar and familiar to her going farther and farther away...
Grandpa's sister, Alexandra, with the help of friends, managed to escape at one of the stops. By common agreement, she was supposed to get (if she was lucky) to France, where at the moment her whole family lived. True, none of those present could imagine how she could do this, but since this was their only, albeit small, but certainly the last hope, it was too much luxury to refuse it for their completely hopeless situation. At that moment, Alexandra's husband, Dmitry, was also in France, with the help of whom they hoped, already from there, to try to help the grandfather's family get out of that nightmare into which life had so ruthlessly thrown them, with the vile hands of brutalized people ...
Upon arrival in Kurgan, they were settled in a cold basement, without explaining anything and without answering any questions. Two days later, some people came for grandfather, and stated that they allegedly came to “escort” him to another “destination” ... They took him away like a criminal, not allowing him to take any things with him, and not deigning to explain where and for how long they are taking it. Nobody ever saw Grandpa again. After some time, an unknown military man brought grandfather's personal belongings to the grandmother in a dirty coal sack ... without explaining anything and leaving no hope of seeing him alive. On this, any information about grandfather's fate ceased, as if he had disappeared from the face of the earth without any traces and evidence ...
The tormented, tormented heart of poor Princess Elena did not want to accept such a terrible loss, and she literally bombarded the local staff officer with requests to clarify the circumstances of the death of her beloved Nikolai. But the "red" officers were blind and deaf to the requests of a lonely woman, as they called her - "from the noble", who was for them just one of the thousands and thousands of nameless "numbered" units that meant nothing in their cold and cruel world ... It was a real hell, from which there was no way out back to that familiar and kind world in which her home, her friends, and everything that she was accustomed to from an early age, and that she loved so much and sincerely, remained .. And there was no one who could help or even gave the slightest hope of surviving.
