Central air conditioning system for liquid cargo ship

Abstract

The present application relates to a kind of central air conditioning system for liquid cargo ship, and it is related to the field of shipbuilding, it includes personnel living cabin, comprising: central air conditioner, can handle mixed outdoor fresh air and indoor return air and send to personnel living cabin;Second fresh air port, it is arranged at the position away from dangerous gas source, it is connected with central air conditioner by second fresh air pipe;Balanced fan, it is arranged on second fresh air pipe between second fresh air port and central air conditioner, only in the working condition of dangerous gas generation, open operation can overcome the resistance of fresh air pipe due to second fresh air pipe arrangement at the remote location, and maintain the positive pressure of cabin relative to cabin outside;Return air fan, return air fan provides power for return air flow.In the working condition of loading and unloading liquid cargo, the central air conditioning system of the present application can still provide normal service, and the possibility of dangerous gas into cabin is reduced to a minimum.

Description

Technical Field

[0001] This invention relates to the field of shipbuilding, and in particular to a central air conditioning system for liquid cargo ships. Background Technology

[0002] During cargo loading and unloading operations on liquid cargo ships, such as oil tankers, chemical tankers, and liquefied gas (LNG, LNG, ethylene, etc.) vessels, the release of volatile hazardous gases during processes like loading, unloading, and tank washing is inevitable. This not only affects the health of the crew but also poses a potential risk of fire and explosion. To prevent hazardous gases from the cargo or fuel systems from entering the crew quarters, doors and windows leading to the outside are kept closed, and air conditioning systems are kept in recirculation mode. However, this not only fails to completely prevent hazardous gases from entering the cabins through natural permeation but also leads to a deterioration in cabin air quality.

[0003] Considering the potential for hazardous gas diffusion, the design of central air conditioning systems for liquid cargo ships primarily faces the following challenges:

[0004] 1) The central air conditioning system should ensure a positive pressure between the cabin area and the external environment to prevent dangerous gases from outside the cabin from entering the cabin through door gaps or occasionally opened exterior doors by natural infiltration.

[0005] 2) In order to ensure the relative positive pressure inside the cabin, all doors and windows leading to the outside of the superstructure need to be closed, and the exhaust ventilation of the galley and bathroom systems also needs to be closed. This will result in no fresh air in the superstructure area, which will seriously reduce the indoor air quality and affect the physiological health of the crew.

[0006] 3) The fresh air inlet of the air conditioner needs to be located in an area where dangerous gases are not easily reached under normal circumstances. The distance is relatively far and it is necessary to overcome the large duct resistance. If it is operated normally, the system noise will increase and the system operating efficiency will be reduced. Summary of the Invention

[0007] The purpose of this invention is to provide a solution for a central air conditioning system that can still provide normal service during the loading and unloading of liquid cargo, while minimizing the possibility of hazardous gases entering the cabin.

[0008] To achieve the above objectives, the present invention provides a central air conditioning system for liquid cargo ships, including crew living quarters, and further comprising:

[0009] The central air conditioning unit is capable of processing the mixed outdoor fresh air and indoor return air and delivering them to the personnel living quarters.

[0010] The second fresh air inlet is located away from the source of hazardous gas and is connected to the central air conditioner via a second fresh air duct.

[0011] A balancing fan is installed on the second fresh air duct between the second fresh air inlet and the central air conditioner. It is activated only when hazardous gases are generated. It can overcome the fresh air duct resistance caused by the second fresh air duct being located at a relatively far position and maintain positive pressure inside the cabin relative to outside the cabin.

[0012] A return air fan, which provides power for the flow of return air.

[0013] Preferably, it also includes a differential pressure sensor to monitor the pressure difference between the inside and outside of the cabin in real time, and to control the balancing fan and the return air fan to maintain a relative positive pressure inside the cabin.

[0014] Preferably, it also includes a first fresh air inlet located in a safe area, which can provide fresh air for the operation of the central air conditioner.

[0015] Preferably, the first fresh air inlet and the second fresh air inlet can be ventilation ducts and / or louvers.

[0016] Preferably, the first and second fresh air inlets are equipped with hazardous gas detection and alarm devices, which can output alarm signals based on the detected hazardous gas concentration and promptly shut down the central air conditioner.

[0017] Preferably, the balancing fan and the return air fan are variable frequency fans.

[0018] Preferably, the central air conditioner can complete the air mixing, cooling, dehumidification, heating and humidification processes, and treat the mixed outdoor fresh air and indoor return air to a suitable temperature and humidity before sending them to the cabin.

[0019] Preferably, the heating function can be implemented by hot water, hot oil, steam, or electric heating; the cooling function can be implemented by vapor compression refrigeration units, absorption units, adsorption units, or expansion refrigeration units.

[0020] Preferably, a remote-controlled air damper is arranged on the fresh air, supply air, and return air ducts of the central air conditioner to control the switching between different states of the central air conditioning system.

[0021] Preferably, fireproof air dampers and cabin access components are also included.

[0022] Compared with existing technologies, the beneficial effects and advantages of the present invention are as follows:

[0023] 1. When loading and unloading fuel or liquid cargo, using a central air conditioning system other than the one described in this invention requires closing the exterior doors of the living area and all exhaust vents, including those in the kitchen, bathrooms, and medical rooms that emit unclean air, to prevent negative pressure from forming indoors. However, this still cannot completely prevent dangerous gases from entering the room through natural infiltration. The solution in this invention, by setting up a second fresh air inlet and a balancing fan to supply air to the central air conditioning system, maintains a relative positive pressure between the indoor and outdoor environments through active air supply, effectively preventing dangerous gases from entering the room through natural infiltration.

[0024] 2. At the same time, necessary ventilation devices such as bathroom exhaust can be turned on to prevent unclean air from the kitchen, bathroom, and medical room from entering the central air conditioning system through return air, thus significantly improving the air quality level in the cabin.

[0025] 3. Install an additional second fresh air vent in a location far from the source of danger, such as near the highest deck of the superstructure or on the other side of the loading and unloading area, to minimize the possibility of dangerous gases entering the central air conditioning system.

[0026] 4. Install differential pressure sensors inside and outside the outer doors of the living area. In conjunction with the frequency conversion function of the balancing fan, adjust the speed of the balancing fan by the pressure difference between the inside and outside, and change the air volume of the balancing fan and the return air fan. This ensures that the positive pressure inside each deck is slightly higher than that outside, but the pressure difference is not too large to affect the opening and closing of the cabin doors and the entry and exit of personnel, while also achieving the effect of reducing energy consumption. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is a schematic diagram of a central air conditioning system according to an exemplary embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the operation of a central air conditioning system under normal operating conditions according to an exemplary embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the operation of a central air conditioning system under the condition of loading and unloading fuel or liquid cargo according to an exemplary embodiment of the present invention.

[0031] Attached reference numerals: 1. Central air conditioner; 2. Variable frequency balanced fan; 3. Return air fan; 4. Second fresh air inlet; 5. First fresh air inlet; 6. Differential pressure sensor; 7. Outlet damper; 8. Inlet damper; 9. Return air damper; 10. First fresh air damper; 11. Second fresh air damper. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention discloses a central air conditioning system for liquid cargo ships. The central air conditioning system can still provide normal service during the loading and unloading of liquid cargo and minimize the possibility of dangerous gases entering the cabin.

[0034] This invention includes a central air conditioner 1 connected to a living quarters, a first fresh air inlet 5 connected to the central air conditioner 1, and a second fresh air inlet 4 connected to the central air conditioner 1. The central air conditioner 1 is connected to the living quarters via a return air duct and a supply air duct. The return air duct can be divided into two paths: one path has an inlet damper 8, a return air fan 3, and an outlet damper 7 arranged sequentially along the return air direction; the other path has a return air damper 9. The central air conditioner 1 is connected to the first fresh air inlet 5 via a conventional fresh air duct, on which a first fresh air damper 10 is installed. The central air conditioner 1 is connected to the second fresh air inlet 4 via a fresh air supply duct, on which a balancing fan and a second fresh air damper 11 are arranged sequentially along the fresh air supply direction. The variable frequency balancing fan 2 and the return air fan 3 are electrically connected to a differential pressure sensor 6. The first fresh air inlet 5 and the second fresh air inlet 4 are equipped with hazardous gas detection and alarm devices.

[0035] Central air conditioner 1 is an air handling unit capable of performing air handling processes such as mixing, cooling, dehumidification, heating, refrigeration, and humidification. It processes the mixed outdoor fresh air and indoor return air to a suitable temperature and humidity before delivering them to the cabin to meet the temperature and humidity requirements of the occupants. The heating function can be achieved through hot water, hot oil, steam, or electric heating, while the cooling function can be achieved through vapor compression refrigeration units, absorption units, adsorption units, or expansion refrigeration units.

[0036] The first fresh air inlet 5 is located in a safe area and includes types such as ventilation ducts and louvers, providing fresh air to the central air conditioning unit 1 when the liquid cargo ship is not in loading or unloading operation.

[0037] The second fresh air inlet 4, including ventilation ducts, louvers, etc., is connected to the central air conditioner 1 through a fresh air duct, providing fresh air to the central air conditioner 1 during the loading and unloading operations of the liquid cargo ship. The second fresh air inlet 4 is located away from the source of hazardous gases, such as on the highest deck of the superstructure or on the other side of the loading and unloading operation area, to reduce the possibility of oil and gas entering the air conditioning fresh air system.

[0038] A balancing fan provides power for the flow of fresh air. Ideally, a variable air volume fan, such as a variable frequency balancing fan 2, should be used. The balancing fan is positioned on the fresh air supply duct between the second fresh air inlet 4 and the central air conditioner 1. It operates only during fuel loading and unloading operations to overcome the resistance in the fresh air duct caused by the relatively distant location of the second fresh air inlet 4, and to maintain positive pressure inside the cabin relative to outside, preventing hazardous gases from entering the cabin through natural infiltration.

[0039] Return air fan 3 provides power for the flow of return air. Ideally, a variable air volume fan, such as a frequency converter return air fan, should be selected. During loading and unloading operations, the proportion of return air in the central air conditioning system increases, requiring the provision of circulation power to overcome excessive duct resistance and ensure the normal operation of the central air conditioning system.

[0040] Remote-controlled air dampers are installed on the fresh air, supply air, and return air ducts of the central air conditioning system to control the switching between different states of the central air conditioning system. They include supply air dampers, inlet air dampers 8, outlet air dampers 7, return air dampers 9, first fresh air dampers 10, and second fresh air dampers 11.

[0041] Differential pressure sensors 6 are installed on both sides of the outer door of the cabin to monitor the natural pressure difference on both sides in real time. This real-time monitoring of the pressure difference between the inside and outside of the cabin door controls the start / stop and airflow of the balancing fan and return air fan 3, optimizing the positive pressure operation of the central air conditioning system. The outer door of the cabin is the door connecting the personnel living compartment to the open external space.

[0042] The hazardous gas detection and alarm device is installed near the first fresh air inlet 5 and the second fresh air inlet 4. It can output an alarm signal based on the detected hazardous gas concentration, and promptly shut down the central air conditioning system to improve the safety of the central air conditioning system.

[0043] In addition, necessary fireproof airlocks and access panels should be installed in accordance with the specifications.

[0044] The variable frequency balancing fan 2 and return air fan 3 operate only during fuel loading and unloading to maintain positive pressure inside the compartment relative to the outside, preventing dangerous oil and gas from entering the compartment through natural infiltration. The second fresh air inlet 4, connected to the balancing fan, is located as far away as possible from the source of oil and gas generation, reducing the possibility of oil and gas entering the air conditioning fresh air system. A differential pressure sensor 6 is installed at the upper exterior door to maintain a slightly positive pressure state inside the compartment by adjusting the variable frequency balancing fan 2 and the variable frequency return air fan. The fresh air inlet connected to the balancing fan is located as far away as possible from the source of oil and gas generation, reducing the possibility of oil and gas entering the air conditioning fresh air system.

[0045] Reference Figure 1The central air conditioner 1 of this invention is used in all ships or offshore platforms that generate hazardous gases in their operations, such as oil tankers, chemical tankers, liquid cargo ships or floating production storage and offloading units. The central air conditioner 1 provides services for the living quarters of personnel.

[0046] Reference Figure 2 Under normal operating conditions, the central air conditioner 1 in this invention provides air conditioning to the living quarters. A portion of the air supplied to the living quarters is exhausted outdoors via methods including kitchen exhaust, bathroom exhaust, and general room exhaust. The outlet damper 7 and inlet damper 8 of the return air fan 3 are closed, while the return air damper 9 on the return air duct is open. The remaining approximately 50% of the return air returns to the central air conditioner 1 via the corridor return air, returning naturally. Under normal operating conditions, the second fresh air damper 11 of the second fresh air inlet 4 is closed, and the first fresh air damper 10 of the first fresh air inlet 5 is open. Approximately 50% of the total air supply volume of the air conditioner enters the central air conditioner 1 through the first fresh air inlet 5. After the fresh air and return air are mixed, they undergo cooling or heating, dehumidification or humidification processes before being delivered by the central air conditioner 1 to each living quarter, regulating the temperature and humidity within the quarters and completing one complete cycle.

[0047] Reference Figure 3 In the case of loading and unloading fuel or liquid cargo, the central air conditioner 1 of this invention provides air conditioning to the living quarters. The exhaust air in the cabins is closed as needed, except for the bathroom exhaust, with only a small amount of air being exhausted outdoors through the exhaust system. The return air damper 9 on the return air duct is closed, while the inlet damper 8 and outlet damper 7 of the return air fan 3 are opened, and the return air fan 3 is turned on, returning more than 70% of the air conditioning supply volume of the return air to the central air conditioner 1. The first fresh air damper 10 of the first fresh air inlet 5 is closed, and the second fresh air damper 11 of the second fresh air inlet 4 is opened, allowing approximately 30% of the total air conditioning supply volume of fresh air to pass through the second fresh air inlet 4. Under the pressure of the balancing fan, the fresh air overcomes the additional duct resistance caused by its distant location and is then sent into the central air conditioner 1. After the fresh air and return air are mixed, they undergo cooling or heating, dehumidification or humidification processes before being sent by the central air conditioner 1 to each living quarter, regulating the temperature and humidity within the cabins and completing one complete cycle.

[0048] Under these operating conditions, the airflow caused by personnel entering and exiting, and changes in the operation of exhaust fans in individual compartments, will alter the return air volume and fresh air supply volume of the entire central air conditioning system. To maintain a slightly positive pressure relative to the outside, differential pressure sensors 6, installed inside and outside the compartment doors, monitor the pressure difference in real time and adjust the airflow of the supply and return air fans 3 accordingly. For example, if an exterior door is opened or a compartment's exhaust fan is suddenly activated, the return air volume needs to be reduced and the fresh air supply volume increased. Ultimately, this method ensures that the positive pressure inside is slightly higher than outside, without causing an excessive pressure difference that could affect the opening and closing of compartment doors and the entry and exit of personnel.

[0049] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A central air conditioning system for a liquid cargo ship, comprising crew living quarters, characterized in that, include: The central air conditioner (1) can process the mixed outdoor fresh air and indoor return air and deliver them to the personnel living quarters; The second fresh air inlet (4) is located away from the source of dangerous gas and is connected to the central air conditioner (1) through the second fresh air duct. The location away from the source of dangerous gas is the highest deck of the superstructure or the other side of the loading and unloading operation area. The variable frequency balancing fan (2) is arranged on the second fresh air duct between the second fresh air inlet (4) and the central air conditioner (1). It is only turned on when dangerous gases are generated. It can overcome the fresh air duct resistance caused by the second fresh air duct being arranged in a far position and maintain the positive pressure inside the cabin relative to outside the cabin. Return air fan (3), which provides power for the flow of return air; The differential pressure sensor (6) monitors the pressure difference between the inside and outside of the cabin in real time and controls the variable frequency balancing fan (2) and the return air fan (3) to maintain a relative positive pressure inside the cabin. Among them, the variable frequency balancing fan (2) and the return air fan (3) are only turned on when loading and unloading fuel, and the air volume is controlled according to the pressure difference monitored by the differential pressure sensor (6) to maintain the positive pressure inside the cabin relative to the outside of the cabin and prevent dangerous oil and gas from entering the cabin through natural permeation. It also includes a first fresh air inlet (5) located in a safe area, which can provide fresh air for the operation of the central air conditioner (1) when the liquid cargo ship is not loading or unloading.

2. The central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, The first fresh air inlet (5) and the second fresh air inlet (4) may be ventilation ducts and / or louvers.

3. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, The first fresh air inlet (5) and the second fresh air inlet (4) are equipped with dangerous gas detection and alarm devices, which can output alarm signals according to the detected dangerous gas concentration and cut off the central air conditioner (1) in time.

4. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, The return air fan (3) is a variable frequency fan.

5. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, The central air conditioner (1) can complete the mixing, cooling, dehumidification, heating and humidification of air, and process the mixed outdoor fresh air and indoor return air to a suitable temperature and humidity before sending them to the cabin.

6. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, Heating functions can be achieved through hot water, hot oil, steam, or electric heating; cooling functions can be achieved through vapor compression refrigeration units, absorption refrigeration units, adsorption refrigeration units, and expansion refrigeration units.

7. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, The remote-controlled air damper is arranged on the fresh air, supply air and return air ducts of the central air conditioner (1) to control the switching between different states of the central air conditioning system.

8. A central air conditioning system for a liquid cargo ship according to claim 1, characterized in that, It also includes fireproof airlocks and access panels.

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