FI129058B - Cargo ship - Google Patents

Abstract

The invention relates to a cargo ship comprising at least one cargo space (3) comprising a deck structure (6) which can be opened and closed. In order to enable the cargo ship to transport large quantities of molded goods from the port of departure to the destination so that moisture or water does not condense On the surfaces of the molded goods, although the temperature of the molded goods in the port of departure is much lower than the outside temperature in the destination, the cargo vessel comprises a heat exchanger (7) connected to the exhaust system (2) of the cargo ship's main engine (1) for transferring heat energy from the exhaust system to the heat exchanger, a first channel (8) for transferring fluid from the heat exchanger (7) to a second heat exchanger, a second channel (9) for returning the fluid from the second heat exchanger to the heat exchanger, a fan system (12) for transporting the air heated in the second heat exchanger to an inlet opening leading to the cargo space and into the cargo space, and an outlet opening for removing air from the cargo hold.

Description

BACKGROUND OF THE INVENTION The invention relates to a cargo ship comprising at least one compartment comprising an openable and closable deck structure for closing a hold. The invention relates in particular to the transport of steel products and other shaped products for further processing on a cargo ship. During transport or in the port, moisture may condense on the surfaces of the molded product. Although molded articles for storage and transportation are generally packaged in various enclosures, such as inside plastic films, the enclosures do not always provide sufficient protection against moisture entering the metal surface of the molded article through the enclosure, oxidizing it. It is practically impossible to make the protective shells so tight that the risk of water condensation on the surface of the molded article can be completely eliminated. If there is even a small hole in the protective cover, moisture can condense on the surfaces of the molded product, oxidizing the molded product quickly.

Oxidation of the molded article is quite common when transporting cold, low temperature loaded massive metallic molded articles, such as steel coils, on a ship that moves during transport to an environment where the temperature and humidity are significantly higher than at the port of departure. In this case, at the latest when the cargo ship arrives at its destination and the hold hatches are opened, warm moist outside air flows into the hold, whereby the dew point is below and the air moisture condenses on the mold covers and the metal surfaces of the mold products. Oxidation of the molded article during transport is a fairly common problem when the molded article has a high mass, as exemplified by the transport of cold steel coils. The individual weight of the steel coils can be, for example, 20 t, and when transported by ship, the total weight can be, for example, 5000 t. Heavy steel coils, especially of unalloyed N steel or low-alloy steel, oxidize, i.e. rust, rapidly when moisture and water enter their surface. The surfaces of the stainless steel rollers 2 can also be damaged by light oxidation under their surface, which is in the form of light spots. The spots are permanent, giving an undesired appearance to the final product, for example a sink. Removing pale 3 oxidation is laborious. Due to the high mass, the temperature of the steel coils in the hold remains low for several days, keeping the hold temperature low, even as the ship moves from a cold environment to a warm environment. When the ship arrives at its destination in winter, the temperature of the hold and the molded article may be several degrees, for example 10 to 15 degrees, or even tens of degrees lower.

higher than the ambient temperature of the ship. Due to the temperature difference, the above-mentioned condensation of moisture on the surface of the molded products takes place when warm moist air flows into the hold at the destination.

FI43954B discloses a ship which e.g. comprises a hold and a drying arrangement for heating this, which includes an air heater.

EP2522571A1 discloses an arrangement for recovering waste heat generated by the main engine of a cargo ship.

GB1211766 A discloses a heat exchanger.

US2005061002 A1 discloses a device for exchanging heat and humidity between two air streams. Brief description of the invention The object of the invention is to provide a cargo ship which eliminates the above-mentioned problem in the transport of molded articles. To achieve this object, the cargo ship is characterized in that it comprises a heating arrangement for heating the hold, comprising: - a heat exchanger connected to the cargo ship's main engine a second heat exchanger comprising a heat transfer surface for transferring the thermal energy contained in the fluid to the air surrounding the heat transfer surface to heat it, a second duct for returning fluid from the second heat exchanger to the heat exchanger, the heat exchanger, the first duct and the second duct forming a circulation for conveying the surrounding heated air to the inlet leading to the hold O for conducting hot supply air to the hold, 2 - for the outlet air p to extract from the hold, the fan arrangement E 30 being adapted to convey the air leaving the hold to the heat transfer surface of the second heat exchanger o as heated supply air to the hold. 3 The hold is thus heated by the thermal energy from the exhaust gases of the ship's main engine, which would otherwise be wasted energy. N Thermal energy is transferred to the heat exchanger in the exhaust system when hot exhaust gases flow in the exhaust system.

Preferably, the heating arrangement is located in the space outside the hold. In this case, when the heating arrangement is at least substantially completely out of the hold, the heating arrangement is not in the way during the loading and unloading of the ship and does not take up space from the hold either.

Preferably, the heating arrangement comprises a first air duct in the second heat exchanger for conducting heated air from the second heat exchanger to the inlet leading to the room, wherein preferably the heating arrangement further comprises a second air duct for conducting air from the outlet to the second heat exchanger. The air ducts allow the heat exchanger to be placed in the desired location on the ship and allow the air to be directed to the inlet opening in a controlled manner and the air to be removed from the outlet in a controlled manner, thus providing thermal energy.

Preferably, the heat exchanger is an exhaust gas / liquid heat exchanger, wherein the fluid flowing in the first channel and the second channel is a liquid adapted to circulate by means of a pump and adapted to receive thermal energy from the exhaust gases in the heat exchanger. The transfer of energy from the exhaust gases to the liquid is very efficient.

Preferably, the cargo ship comprises a dehumidifier for removing moisture from the air of the hold, thereby ensuring that any moist air in the hold cannot condense on the surfaces of the molded product during transport of the cargo.

Preferred embodiments of the invention are set out in the appended dependent claims.

The invention also relates to the use of a cargo ship as defined in the appended claims in the chartering of steel molded articles.

The main advantage of the cargo ship according to the invention is that it allows high-mass molded articles to be transported from the port of departure to the destination so that no moisture or water condenses on the molded surfaces = even if the temperature of the molded articles in the port of departure is much lower than the outdoor temperature at destination. The cargo ship according to the invention is particularly suitable for transporting heavy metal cargo in the form of various shaped products during the winter E from a cold country north to a warmer country further south. Brief description of the figures N The invention will now be described in more detail by means of two embodiments - with reference to the accompanying drawing, in which Figure 1 illustrates a cargo ship according to the invention,

Fig. 2 illustrates a section along the line II-II in Fig. 1, Fig. 3 illustrates an enlarged section of the first embodiment of the ship along the line III-III in Fig. 1, i.e. from above, Fig. 4 illustrates the contents of Fig. 3 in a side view, Fig. 5 illustrates an enlarged view of the cargo corresponding to the view of Figure 3, and Figure 6 illustrates the contents of Figure 5 in a side view corresponding to the view of Figure 4.

DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows an example of a cargo ship according to the invention. In the figure, reference numeral 1 indicates the main engine of the ship, and reference number 2 the exhaust piping of the main engine 1. The ship's hold 3 is loaded with both steel coils 4 and steel plates stacked into steel plate stacks 5. The steel coils 4 are at the bottom of the hold 13. The steel plate stacks 5 are on the ship's intermediate deck 11. Instead of or in addition to steel coils 4 and / or steel plate stacks 5, the cargo may consist of other cargo , but the cargo ship according to the invention is especially intended for chartering heavy shaped products such as steel coils, steel plates and steel profiles. The total mass of molded products is large, several hundred tons, even thousands of tons. The hold 3 is covered by an openable and closable lid structure 6, which comprises a lid hatch, which covers the hold preferably watertight and sometimes also airtight.

The cargo ship comprises a heating arrangement for heating the hold 3 and the cargo to be carried inside it. The following describes the devices and components included in the heating arrangement.

The exhaust piping 2 of the ship's main engine 1 is associated with a heat exchanger 7 for transferring heat energy from the exhaust gases of the exhaust piping to the fluid flowing in the heat exchanger. The fluid is preferably a liquid, with the heat exchanger N 7 being an exhaust gas / liquid heat exchanger. The liquid may preferably be an aqueous solution with no risk of freezing, for example a water-glycol mixture. Alternatively, the liquid 2 may, for example, be a heat transfer oil, a so-called hot oil, which is known to be used in hot oil boilers. The amount of thermal energy o obtained from the exhaust piping 2 is large in the case of the ship's main engine 1, the power of which can be 3, for example 5000 - 20,000 kW. When the main engine 1 of the ship is running at normal temperature, the temperature of the exhaust gases flowing in the exhaust piping 2 is 200 to N 320 ° C. From the heat exchanger 7, the first channel 8 leads to a second heat exchanger 20, which is located partly in a space 14 outside the hold 3. Ku-

in the case of faults, this space 14 is a storage room located between the bodies 3 and 15.

The channel 8 passes into the space 14, preferably along the side tank of the ship (cf. reference numerals 17a, 17b), which is outside the hold 3, or along another space outside the hold.

The side tank is preferably a dry tank 17a, but may alternatively be a side weight cargo tank 17b (or some other space outside the hold). From the second heat exchanger 20 the second duct 9 leads back to the heat exchanger 7. Like the duct 8, the duct 9 is located in the space 14 outside the hold 3 and passes from the second heat exchanger 20 to the heat exchanger 7, preferably along the dry tank 17a of the ship; or may also run along the ship's side ballast tank 17b or along other space outside the hold.

The channels 8, 9 form a closed circuit in which the liquid is made to circulate by means of a pump 10.

There may be several pumps, but a single pump 10 is sufficient to circulate the liquid.

It should be noted that although the liquid in the closed circuit is an aqueous solution, the temperature of the aqueous solution in the closed circuit can be well above 100 ° C because the aqueous solution cannot boil in the closed circuit where it is under pressure.

The second heat exchanger 20 comprises a heat transfer surface 20a for transferring the thermal energy contained in the liquid to the air surrounding the heat transfer surface to heat it.

When a liquid releases thermal energy into the surrounding air, the thermal energy contained in the liquid decreases and the temperature of the liquid decreases.

The second heat exchanger 20 preferably comprises a cellular structure (not shown) which forms a heat transfer surface 20a.

The honeycomb structure has in practice several heat transfer surfaces.

Alternatively, the second heat exchanger 20 comprises a radiator-like rival structure which forms a heat transfer surface (practically several heat transfer surfaces). The second heat exchanger 20 is associated with a fan arrangement 12 comprising a fan N (fan) for transferring the thermal energy of the liquid flowing through the second heat exchanger from the heat transfer surfaces 20a of the second heat exchanger to the surrounding air and further to the first air duct 21 leading to the hot air inlet 22 to lead to the hold to heat the hold air and E the cargo in the hold.

The inlet 22 is fitted to the wall of the hold 3 °.

The air duct 21 is located in the space surrounding the hold 3.

In the case of Figures 3, the air duct 21 is arranged partly in the space 14 (storage room) which is between the bodies 3 and 15 and in the dry tank 17a.

From the hold 3, a second air N 35 duct 24 leads from the hold outlet 23 to the second heat exchanger 20. The outlet

23 is fitted to the wall of the hold 3.

The air duct 24 is located around the hold 3

The air duct 24 removes air from the hold 3 at a temperature lower than the temperature of the air coming from the inlet 22. The air outlet 23 is preferably located remote from the air inlet 22, preferably so that the outlet 23 is located on the first wall of the hold 3, the inlet 22 being located on the second wall of the hold, which is preferably opposite to the first wall. As the liquid circulates in the ducts 8, 9 and the air circulates in the air ducts 21, 24, the air flows in the hold 3, whereby the air and the cargo are heated. In Figures 3 and 4, arrows 01 and 02 illustrate the flow of air in the hold 3. The temperature of the liquid in the channel 9 is lower than in the channel 8; and the air temperature in the air duct 24 is lower than in the air duct 21. The temperature of the liquid coming from the duct 9 increases in the heat exchanger 7. The temperature of the air coming from the air duct 24 increases in the second heat exchanger 20.

The fan of the fan arrangement 12 may be part of the second heat exchanger 20, i.e. integrated in the second heat exchanger, or it may be separate from this.

For example, if the temperature of the cargo is -15 ° C and its mass is several tons and tons, even thousands of tons, the air must circulate in the hold 3 for several tens of hours in order for the temperature of the cargo to rise to +10 ° C, for example 25 ° C. Very high thermal energy is required to heat heavy cargo by several tens of degrees. In practice, a heat source other than the ship's main engine 1 is not sufficient for heating. The heating of the hold 3 does not cause any heating costs, because the heat from the main engine 1 is waste heat. The pump 10 and the fan arrangement 12 naturally consume energy, but their energy consumption is low. Due to the fact that the cargo heats up during transport, the risk of moisture and water condensing on the surface of the cargo is reduced if the cargo comes into contact with warm, humid outside air, for example at the destination.

In Figs. 1, 3 and 4, reference numeral 16 denotes a dehumidifier N for removing moisture from the air of the hold 3. For the sake of simplicity, the cargo shown in Fig. 1 in the hold 3 or the intermediate deck 7 is not drawn in Figures 3 = and 4. The dehumidifier 16 is important when, for one reason or another, there is or may be moisture in the hold 3. For example, moisture can form in the hold 3 if the cargo is icy during loading, so that as the temperature rises to the temperature stage, the ice can melt to form moisture and water. The dehumidifier 16 is arranged in the space outside the hold 3 = 14 (in the storage room in Figures 3 and 4) between the outlet 23 and the inlet 22, N 35 being adapted to receive air from the hold through the outlet through the air duct 24 and supply air to the inlet through the air duct 21. is lower than the moisture content of the air leaving the hold. The air duct 24 leads from the outlet 23 to a dehumidifier 16 located upstream of the second heat exchanger 20 with respect to the direction of air circulation. From the dehumidifier 16, dehumidified air is directed to be heated to a second heat exchanger 20, from which the fan arrangement 12 supplies heated dry air to the air duct 21 and further to the inlet.

22. The second heat exchanger 20, the air duct 21, the hold 3, the air duct 24, the dehumidifier 16 form an air circulation in which the air leaving the hold 3 is replaced by hotter and drier air leaving the exhaust.

Reference numeral 18 denotes a pipe for supplying external, regenerating air (cf. arrow A) to the dehumidifier 16, and reference numeral 19 denotes a pipe for discharging very moist exhaust air (cf. arrow B) to the outside air. The dehumidifier 16 is preferably such that it comprises a rotating member in which an interaction of air currents (regenerative air from the tube 18 and air from the air duct 24) occurs, resulting in dehumidification of the air coming from the air duct 24 before the air is led to the air duct 21. The dehumidifier 16 will not be described in detail in this context because suitable dehumidifiers are widely available around the world. A suitable dehumidifier is supplied, for example, by Munters, an internationally extensive company. For example, Munters Europe AB, Sweden, operates in Sweden, and Munters Finland Oy operates in Finland. Munters has several offices around the world. U.S. Pat. No. 3,800,859 and U.S. Pat. No. 2002/0129614 describe dehumidifiers which can be used. Instead of the one shown, the dehumidifier can be such that it collects moisture from the hold 3 in a tank which is emptied from time to time if necessary. In principle, the dehumidifier can be any device with which sufficient moisture can be removed from the hold. Thus, the dehumidifying device can in principle be such that its dehumidification is based on the use of a chemical substance, which chemical substance 7 absorbs moisture.

A 30 For simplicity, no arrangement is shown in Figure 1 for heating the other bodies 15, 26 of the ship E. However, the arrangement in the body 15, 26 is similar to that in the body 3. It is easy to provide heating and, if desired, dehumidification of the body 15, 26 by arranging ductwork corresponding to the ducts associated with the hold 3 =.

N 35 Reference numeral 29 in Fig. 1 indicates a temperature measuring device for measuring the air temperature in the hold 3. The control device 30 is adapted in response to the

for a signal from the path 29 to control the flow of liquid flowing in the first channel 8 and the second channel 9, for which the control device preferably controls the speed of the pump 10.

If the measured temperature is found to be below the target temperature (e.g. + 10 ° C), i.e. the temperature is found to be too low, the controller 30 increases the speed of the pump 10, and if the target temperature is reached and does not need to be raised, the controller reduces the pump speed or stops the pump.

Reference numeral 25 denotes a control device for adjusting the blowing power of the fan arrangement 12 in response to a signal from the measuring device 29 (by controlling the fan speed of the fan arrangement). The power of the fan arrangement 12 is increased if the measured temperature is found to be below the target temperature and the fan arrangement is reduced or stopped if the target temperature is reached.

The control devices 30, 25 can be controlled by means of a computer unit (not shown) which receives a signal from the measuring device 29.

The control device for controlling the fan arrangement 12 may be the same control device as that which controls the rotational speed of the pump 10.

Reference numeral 31 in Fig. 1 indicates a humidity measuring device for measuring the moisture content of the air in the hold 3.

The control device 34 is adapted in response to a signal from the measuring device 31 to adjust the operating efficiency of the dehumidifier 16.

If the measured humidity is found to be above the target humidity, i.e. the humidity is found to be too high, the control device 34 increases the rotational speed of the pump 10, increasing the flow rate of the liquid in the duct 8, and if the target humidity is reached and the humidity does not need to be reduced, the control device 34 reduces or stops the pump. pump.

It is conceivable that the control device 34 is alternatively or additionally adapted to adjust the blowing power of the fan arrangement 12.

If the measured humidity is above the target humidity, the control device increases the rotational speed of the fan arrangement and if the target humidity is reached, the control device reduces the rotational speed of the fan arrangement or stops the fan arrangement.

The control of the control device 34 may be implemented by means of a computer unit (not shown 7) which receives a signal from the measuring device 31. m 30 From the above description, it is understood that the cargo ship E according to the invention is very closely related to the fact that the cargo ship is loaded with a heavy metal shaped cargo.

Thus, the invention is also to be understood as a cargo ship 3 loaded with a heavy metallic shaped cargo. Figures 5 and 6 illustrate another embodiment of the invention.

N 35 In Figures 5 and 6, reference numerals similar to those in Figure 3 are used for the corresponding components.

The embodiment of Figure 4 differs from the embodiment of Figures 1 to 3 in that there is no dehumidifier 16.

Meaning of reference numbers used in the drawing: 1 cargo ship main engine 2 exhaust piping 3; 3 hold 4 steel coil 5 steel plate pack 6 deck structure 7 heat exchanger 8; 8 first duct 9: 9 second duct 10; 10 pump 11 selection cover 12; 12 fan arrangement 13 bottom of hold 14 space outside hold (storage room) 15 hold 16 dehumidifier 17a dry tank 17b side weight cargo tank 18 tube for resuscitation air 19 tube for moist exhaust air 20; 20 'second heat exchanger 20a; 20a 'heat transfer surface 21; 21 of the second heat exchanger first air duct N 22; 22 air inlet = 23; 23' air outlet 7 24; 24 second air duct v 30 25 control device E 26 hold o 29; 29 ’temperature measuring device 3 30 control device = 31; 31 humidity measuring device.

The invention has been described above by means of only one embodiment thereof, and it is therefore pointed out that the invention can be implemented in detail in many different ways within the scope of the appended claims. It is conceivable that part of the hold 3; 3 ’or body 3, 15, 26; The amount of heat transferred 3 'is taken from the cooling water of the ship's main engine, but only a part, because cooling water with a temperature of about 60 ° C alone cannot in all cases transfer enough heat to the body to solve the problem underlying the invention. . Naturally, the cargo ship according to the invention can be utilized for transporting cargo other than molded articles. Accordingly, the ship according to the invention can be used to transport, for example, machines and equipment which it is desired to protect from moisture when the dew point is below. The dehumidifier 16 is not necessary if there is no moisture in the load and in the load compartment. For fan arrangement 12; 12 ’may include multiple fans. It is conceivable that in channels 8, 9; 8, 9 'flows air instead of liquid. At least in principle, it is conceivable that there is no actual air duct 21; 21 'in a second heat exchanger for introducing heated air into the space 3; 3 ', wherein the second heat exchanger 20 is arranged in the inlet 22 in the wall of the hold; 22 ’. Correspondingly, it is conceivable that there is no actual air duct 23 in the hold 3; 3 'for directing the exhaust air to a dehumidifier 16 or a fan arrangement 12', the dehumidifier or the fan arrangement being fitted in an outlet 23 in the wall of the hold; 23 '.

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Claims (16)

Patent claims Cargo ship comprising at least one hold (3; 3 ') comprising a deck structure (6) which can be opened and closed (6; 6') to close the hold, a fan system (12; 12 ') for transporting air which supply air to an inlet opening (22; 22 ') leading to the cargo hold and into the cargo hold and for removing air as outgoing air from the cargo hold through the cargo space's outlet opening (23; 23'), and a heating system for heating the air before it is transported as supply air to the cargo hold, characterized in that the heating system is arranged to heat supply air to be led to the cargo hold and to heat the hold, for which purpose the heating system comprises: - a heat exchanger system (7) connected to the cargo vessel's main engine (1) exhaust pipe from the exhaust pipe system to a fluid flowing in the heat exchanger to increase its heat energy, - a first channel (8; 8 ') for transferring the fluid containing added heat energy from heat the exchanger (7) to a second heat exchanger (20; 20 ') comprising a heat transfer surface (20a; 20a') for transferring the heat energy contained in the fluid to the ambient air of the heat transfer surface to heat it, a second channel (9; 9 ') for returning the fluid from the second the heat exchanger (20; 20 °) to the heat exchanger (7), the heat exchanger, the first channel (8; 8) and the second channel (9: 9 ') forming a circuit with the fluid, and said fan system (12; 12') ) is arranged to transport the heated air surrounding the heat transfer surface (20a; 20a ') of the second heat exchanger (20; 20') to the inlet opening (22; 22 ') leading to the cargo space (3; 3') to lead the hot supply air into the cargo hold and is arranged to transport through the cargo space's outlet opening (23; 23 ') removed air to the heat transfer surface (20a; 20a') of the second heat exchanger (20; 20 ') to be heated to hot supply air to be led to the O cargo space. Cargo ship according to claim 1, characterized in that the heating system is located in a space outside the cargo hold (3; 3 "). Cargo ship according to claim 1 or 2, characterized in that the heating system comprises a first air duct (21; 21 ') for guiding the air heated from the second heat exchanger 2 in the second heat exchanger (20; 20'). the inlet to the inlet opening (22; 22 ') leading to the cargo space (3; 3 °). Cargo ship according to claim 1, 2 or 3, characterized in that the heating system comprises a second air duct (24; 24 ') for guiding air from the outlet opening (23; 23') of the cargo space (3; 3 ') to the second heat exchanger (20; 20). Cargo ship according to one of the preceding claims, characterized by a moisture removal apparatus (16) for removing moisture from the air of the hold (3). Cargo ship according to claim 5, characterized in that the moisture removal apparatus (16) is arranged in a space outside the cargo space (3) between the cargo space outlet opening (23) and the cargo space inlet opening (22), it being arranged to receive air removed from the cargo space through the outlet opening and to supply air to the cargo space outlet opening (22), the moisture content of which is lower than that of the air removed from the cargo space. Cargo ship according to claim 5 or 6, characterized in that the moisture removal apparatus (16) is arranged upstream of the second heat exchanger (20; 20 ") with respect to the direction of circulation of the air. Cargo ship according to claim 7, characterized in that the moisture removal apparatus (16) comprises a fan which is part of the fan system (12; 12). Cargo vessel according to any one of the preceding claims, characterized in that the heat exchanger (7) is an exhaust / liquid heat exchanger, the fluid flowing in the first channel (8; 8 ') and the second channel (9; 9 ') is liquid which is arranged to circulate by means of a pump (10; 10') and which is arranged to receive heat energy from exhaust gases in the heat exchanger (7). Cargo ship according to claim 9, characterized in that the first channel (8; 8 ') and the second channel (9; 9') form a closed circuit. Cargo ship according to one of the preceding claims 9 to 11, characterized in that the detilastrum (3; 3 ') has a moisture measuring device (31; 31') for measuring the moisture in the air of the hold, and a control device (34) = for regulating the power of the pump (10; 10 '). 7 Cargo ship according to any one of the preceding claims 9 - 11, A 30, characterized in that the detilastrum (3; 3 ') has a moisture measuring device (31; 31') for measuring the moisture in the air of the hold, and a control device ( 34) o for regulating the blowing power of the fan system (12; 12 "). 3 Cargo ship according to one of the preceding claims, characterized in that the detila cargo hold (3; 3 ') has a temperature measuring device (29; 29') for measuring the temperature of the cargo hold air, and a control device ( 30) to control the amount of fluid flowing in the first channel (8; 8). Cargo ship according to one of the preceding claims, characterized in that the detilastrum (3; 3 ') has a temperature measuring device (29; 29) for measuring the temperature of the cargo air, and a control device (25) for to regulate the blowing power of the fan system (12; 12 '). Cargo ship according to one of the preceding claims, characterized in that the heat transfer surface (20a; 20a ') of the second heat exchanger (20; 20' ') consists of a cellular structure. Use of a cargo ship according to any one of the preceding claims in the transport of molded goods (4, 5) of steel. N O N> LO I a a o O O LO © O N