CN110901870A

CN110901870A - System and method for utilizing cold energy of ship LNG (liquefied Natural gas) for refrigerated container

Info

Publication number: CN110901870A
Application number: CN201911378330.3A
Authority: CN
Inventors: 李博洋; 杨倩倩; 张新光; 张宝收; 张瑞; 张运秋; 张晓荣; 马钰强
Original assignee: Qingdao University of Science and Technology
Current assignee: Qingdao University of Science and Technology
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-03-24
Anticipated expiration: 2039-12-27
Also published as: CN110901870B

Abstract

The invention discloses a system and a method for utilizing ship LNG cold energy for a refrigerated container. When the LNG fuel is consumed during the navigation of the ship on the sea, 50% glycol solution is adopted as the refrigerant to exchange heat with the LNG fuel, the refrigerant which obtains cold energy sequentially enters the refrigerated container heat exchanger through the liquid supply pipe, the quick connector and the electromagnetic valve, and the cold energy is released for refrigeration, so that the cold energy of the ship LNG fuel is used for refrigerating the refrigerated container, the consumption of a heat source in the gasification process of the LNG fuel can be reduced, the load of a ship power grid is reduced, the problem that the load of the ship power grid is huge due to the refrigeration of the refrigerated container of a large LNG power container ship is solved, the reasonable utilization of energy is realized, the supply pipeline system and the refrigerated container utilization system are connected by adopting a hose, the quick connector and the like, the problem of the utilization of the LNG cold energy by a mobile refrigerating device is solved, and the economy of the ship is.

Description

System and method for utilizing cold energy of ship LNG (liquefied Natural gas) for refrigerated container

Technical Field

The invention belongs to the technical field of ships, and relates to a refrigeration box system and a refrigeration box method for an LNG power ship to utilize LNG cold energy.

Background

The International Maritime Organization (IMO) promulgates "global sulfur limits" are on the vercoming, stipulating: since 2020, the sulfur content of all marine fuels worldwide has been reduced from 3.5% to 0.5%. Therefore, the realization of energy conservation and emission reduction and the search for new alternative energy sources of ships become the urgent primary tasks of the shipping industry.

Liquefied Natural Gas (LNG) has the advantages of low temperature, large gas-liquid expansion ratio, high energy efficiency, easy transportation and storage, etc., and LNG is currently recognized as an ore fuel with minimal pollution, and if the LNG is used as a substitute for fuel oil, greenhouse gas emission can be reduced by limiting emission pollution, thereby improving air quality. Thus, LNG-powered vessels (vessels using LNG as fuel) are more environmentally friendly than existing fuel-powered vessels.

With the increasingly fierce competition of the world container transportation market, in order to improve the transportation efficiency and the scale economic benefit of the containers, the container ships are becoming large-scale, and the container ships have higher requirements on the speed, so the power of the ships is very high, the daily fuel consumption of the container ships is particularly large, the emission pollution of the ships is serious, and if the LNG is used as fuel, the effects of energy conservation and emission reduction are more obvious, so that more and more LNG powered container ships are made.

LNG is a cryogenic liquid, the storage temperature is-163 ℃ generally, LNG is stored in a liquid state on an LNG fuel power ship, LNG needs to be gasified and heated to about 20 ℃ to 45 ℃ for use before being sent to a main power device of the ship for combustion, the LNG releases large cold energy in the gasification process, and some ships can consume more than 100 tons of LNG every day with the trend of large-scale container ships at present, so that a large amount of LNG cold energy can be utilized on the ships.

The patent number CN 209176893U discloses a ship refrigeration house and an air conditioning system based on LNG cold energy; the patent number CN 209176893U discloses a refrigerator operating device for refrigeration by using cold energy of liquefied natural gas; the patent number CN 105444309A discloses an LNG marine air conditioner and refrigeration house system; patent number CN 208520077U discloses a ship cold storage and air conditioner control system using LNG cold energy; the air conditioner and the refrigeration house system for the LNG ship disclosed in the Chinese patent with the patent number of CN 105444309A use the LNG cold energy for refrigeration of the refrigeration house and the air conditioner, and realize cascade utilization of the LNG cold energy.

The LNG cold energy is used in a ship refrigeration house and an air conditioning system, the LNG cold energy is utilized, certain benefits are achieved for energy conservation and emission reduction, but the control system is simple in design, the cold energy recycled by the system is too little, the system power is only a few kilowatts if the system power is small, and is not more than 20-30 kilowatts if the system power is large, and therefore a large amount of LNG cold energy is still not utilized. In addition, the refrigeration house and the air conditioner belong to relatively fixed systems and are relatively easy to design. If the LNG cold energy is utilized in a large amount and is applied to mobile refrigeration equipment, the design method has better practical significance.

At present, containers carried by a container ship are generally divided into two types, one type is a common container, the other type is a refrigerated container, wherein the refrigerated container is provided with a refrigerating unit and needs to consume electric power for refrigeration, the refrigerated container needs to consume ship electric power during sea navigation, in addition, the carrying capacity of the existing container ship is very large, and the number of the refrigerated containers carried by a large LNG power container ship can reach thousands of TEUs (TEUs, standard containers). Therefore, the power supply load of the power grid of the ship cabin can reach thousands of kilowatts, and is even larger, and the fuel consumption and equipment investment cost of the ship due to power supply are greatly increased. If the cold energy of the LNG fuel of the ship is used for refrigerating the refrigerated container, the consumption of a heat source in the process of gasifying the LNG fuel can be reduced, the load of a ship power grid is greatly reduced, the reasonable utilization of the energy is realized, and the economy of the ship is improved.

Disclosure of Invention

The invention aims to solve the problems and provides a system and a method for utilizing LNG cold energy of a ship by using a refrigerated container.

The first object of the invention is to provide a system for utilizing the LNG cold energy of a ship by using a refrigerated container, which mainly comprises a refrigerated container cold energy utilization system, a supply pipeline system and an LNG fuel supply system.

Wherein, the refrigerating energy utilization system of the refrigerator mainly comprises: the system mainly comprises an electromagnetic valve (a), a temperature relay (b), a bulb (c), an inlet quick connector (d), an outlet quick connector (e) and a refrigerated container heat exchanger (f), and the system has the main function that cold energy displaced from LNG fuel is used for refrigerating goods.

The supply line system mainly includes: the first circulating pump (7), the liquid supply pipe (8), the liquid return pipe (11) and the liquid return pipe thermometer bulb (12) are mainly used for conveying the refrigerant A to the refrigeration container.

The LNG fuel supply system mainly includes: the device comprises a transfer pump (1), an LNG fuel tank (2), a booster pump (3), a temperature control three-way valve (4), a first heat exchanger (5) and a cylinder liner water heating system.

The supply pipeline system is filled with 50% of glycol aqueous solution as a refrigerant A to exchange heat with low-temperature LNG in a first heat exchanger (5), the glycol aqueous solution after heat exchange enters a refrigerated container heat exchanger (e) of the refrigerating box cold energy utilization system through a liquid supply pipe (8), the temperature of the glycol aqueous solution is lower than that in a container, so that heat is absorbed in the refrigerated container heat exchanger (e) to achieve the purpose of cooling goods in the refrigerated container, and the glycol aqueous solution after heat release returns to the first heat exchanger through a liquid return pipe (11) to form a cycle.

Further, the LNG fuel supply system mainly comprises the following processes: LNG is transported out from an LNG fuel tank (2) through a lightering pump (1) and is transported to a main power device of a ship through a booster pump (3). Considering temperature conditions, a part of cold energy is released by passing through the first heat exchanger (5), then passes through the second heat exchanger (6), and a circulation pipeline where the second circulation pump (9) is located is filled with a refrigerant B, namely a 40% ethylene glycol aqueous solution, and is used for heating natural gas to reach the temperature required by combustion of 20-45 ℃; or the LNG does not pass through the first heat exchanger (5) and is directly led to the second heat exchanger (6) through a bypass loop of the temperature-controlled three-way valve (4). In the cylinder sleeve water heating system, cylinder sleeve water is adopted to heat a refrigerant B in a third heat exchanger (10), and then the refrigerant B is used for heating natural gas to reach the temperature required by combustion of the natural gas, which is an indirect heating process. The reason why the cylinder liner water is not used for directly heating the natural gas in the second heat exchanger (6) is that: the method can avoid the phenomenon that the refrigerant is solidified to block the pipeline under the extreme condition.

Further, the refrigerated container is different from the traditional refrigerated container in that a group of heat exchange coil pipes, namely the refrigerated container heat exchanger (e), are additionally arranged between the original air cooler and the evaporator in the refrigerated container in the system.

Furthermore, an inlet quick connector (d), a temperature relay (b) and an electromagnetic valve (a) are arranged at the refrigerant A inlet of the refrigerated container, and an outlet quick connector (f) is also arranged at the refrigerant A outlet, so that the temperature of the refrigerated container is controlled.

Further, the inlet quick connector (d) and the outlet quick connector (f) can automatically seal liquid in the pipe when being disconnected, and liquid cannot leak at the joints.

The second purpose of the invention is to provide a method for utilizing the cold energy of the ship LNG for the refrigerated container based on the system for utilizing the cold energy of the ship LNG for the refrigerated container.

On an LNG power ship, LNG is conveyed out of an LNG fuel tank (2) through a lightering pump (1), and generally is gasified to about 20-45 ℃ through a series of steps to be sent to a main power device of the ship for burning.

LNG pressurized by the booster pump (3) passes through the temperature control three-way valve (4), the temperature control three-way valve (4) is connected with a liquid return pipe temperature bulb (12) arranged at a liquid return pipe (11) close to the first heat exchanger (5), and the flow of the LNG of a bypass pipeline of the temperature control three-way valve (4) can be controlled according to the temperature. When the temperature of the liquid return pipe (11) is lower than minus 25 ℃, the LNG main pipeline valve leading to the temperature control three-way valve (4) is closed, meanwhile, the valve of the bypass pipeline is opened to the maximum, LNG directly enters the second heat exchanger (6) through the bypass pipeline without passing through the first heat exchanger (5), and therefore the phenomenon that the temperature in the pipeline is too low, the freezing point of the refrigerant A is reached, and the blockage phenomenon occurs can be avoided; when the temperature of the liquid return pipe is higher than-23 ℃, the LNG can partially or completely pass through the first heat exchanger (5).

LNG exchanges heat with refrigerant A, namely 50% glycol water solution, in the supply pipeline system at the first heat exchanger (5), the refrigerant A absorbs cold energy released by the LNG, enters the supply pipeline system through the liquid supply pipe (8), and then enters the refrigerating energy utilization system of the refrigerating box through the inlet quick connector (d).

The refrigerated container in this system is retrofitted with a set of heat exchange coils, i.e., the refrigerated container heat exchanger (e), added to the original refrigerated container evaporator. When the ship sails at sea and LNG fuel is consumed, under the action of the first circulating pump (7), the refrigerant A absorbs LNG cold energy in the first heat exchanger (5) and sequentially enters the refrigerated container through the liquid supply pipe (8), the inlet quick connector (d) and the electromagnetic valve (a), at the moment, the refrigerated container heat exchanger (e) is filled with the refrigerant A which absorbs the LNG cold energy, the original air cooler in the container works, and the refrigerant A releases the cold energy for refrigeration.

Furthermore, a temperature bulb (c) for sensing temperature is arranged in the refrigeration container, when the temperature in the container reaches the lower limit of the required refrigeration temperature, a signal can be transmitted to the temperature relay (b) so as to control the electromagnetic valve (a) to be closed, and similarly, when the temperature in the container rises to the upper limit, the temperature bulb (c) can send a signal to the temperature relay (b) so as to control the electromagnetic valve (a) to be opened; when the ship is moored without LNG fuel consumption, the refrigerated container is cooled by consuming electric power like a conventional refrigerated container.

Further, the cylinder sleeve water heating system is used for ensuring that the natural gas can reach the required temperature before entering the main power device of the ship to be combusted no matter how much LNG cold energy is consumed by the refrigerated container, and the temperature is generally 20-45 ℃.

The invention has the beneficial effects that:

under the trend of large-scale container ships, the number of the refrigerated containers is large, the invention not only can utilize a large amount of cold energy stored in LNG fuel to the maximum extent and greatly improve the energy utilization efficiency, but also saves a large amount of electric power required by refrigeration of the refrigerated containers, and solves the problem of overlarge power grid load of the container ships caused by the electric power consumption of the refrigerated containers.

The system and the method for utilizing the LNG cold energy of the ship for the refrigerated container disclosed by the invention have the advantages that the system connection is convenient, the method is easy to realize, the working efficiency is high, and more importantly, the problem that the LNG cold energy on the ship is directly applied to the mobile refrigeration equipment is solved.

The refrigerated container provided by the invention not only can realize the effective utilization of LNG cold energy on an LNG power ship, but also has the functions of a common refrigerated container when no LNG fuel is consumed during the berthing of the ship, so that the redundancy is increased, and the reliability of a refrigeration system of the refrigerated container is improved.

Drawings

FIG. 1 is a system diagram of a refrigerated container utilizing cold energy of LNG (liquefied Natural gas) of a ship

FIG. 2 is a schematic diagram of a refrigerated container utilizing LNG cold energy

FIG. 3 is a schematic view of the installation position of the heat exchanger of the refrigerated container

FIG. 4 is a schematic view of the relative positions of a refrigeration unit for a refrigerated container

FIG. 5 is a schematic view showing the connection of lashing bridges to refrigerated containers

FIG. 6 is a schematic view of the distribution of refrigerated containers on a ship

In the drawings: 1. lightering pump 2, LNG bunker 3, booster pump 4, temperature control three-way valve 5, first heat exchanger 6, second heat exchanger 7, first circulating pump 8, liquid supply pipe 9, second circulating pump 10, third heat exchanger 11, liquid return pipe 12, liquid return pipe temperature bulb a, electromagnetic valve b, temperature relay c, temperature bulb d, inlet quick connector e, refrigerated container heat exchanger f, outlet quick connector

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and embodiments

Referring to fig. 1, the invention discloses a system for using cold energy of ship LNG for a refrigerated container, which mainly comprises: lightering pump (1), LNG fuel tank (2), booster pump (3), temperature control three-way valve (4), first heat exchanger (5), second heat exchanger (6), first circulating pump (7), liquid supply pipe (8), second circulating pump (9), third heat exchanger (10), liquid return pipe (11), liquid return pipe thermal bulb (12), electromagnetic valve (a), temperature relay (b), thermal bulb (c), inlet quick joint (d), refrigerated container heat exchanger (e), outlet quick joint (f)

The supply line system mainly includes: a first circulating pump (7), a liquid supply pipe (8), a liquid return pipe (11) and a liquid return pipe thermometer bulb (12).

The supply pipeline system is filled with 50% glycol aqueous solution as a refrigerant A to exchange heat with low-temperature LNG in a first heat exchanger (5), the glycol aqueous solution after heat exchange enters a refrigerated container heat exchanger (e) of the refrigerating box cold energy utilization system through a liquid supply pipe (8), the temperature of the glycol aqueous solution is lower than that in a container, so that the glycol aqueous solution absorbs heat in the refrigerated container heat exchanger (e) to refrigerate the refrigerated container, and the glycol aqueous solution after heat release returns to the first heat exchanger through a liquid return pipe (11), thereby forming a cycle.

Further, as shown in fig. 2, an inlet quick coupling (d), a temperature relay (b) and an electromagnetic valve (a) are arranged at an inlet of a refrigerant a of the refrigerated container, and an outlet quick coupling (f) is also arranged at an outlet of the refrigerant a, so that the temperature control of the refrigerated container is realized.

Further, the foregoing has focused on the refrigerated container a of section a of fig. 1₁In the same way, the refrigerated container A of the area A₂And a refrigerated container A₃And a refrigerated container A₄… … refrigerated container A_nThe same principle applies, and similarly, the same applies to the refrigerated container principle of the B area and the C area. This also allows for more area expansion, solving the refrigeration problem of a greater number of containers, even up to thousands of refrigerated containers.

On an LNG power ship, LNG is conveyed out of an LNG fuel tank (2) through a lightering pump (1), and generally is gasified to about room temperature through a series of steps before being sent to a main power device of the ship for combustion.

The reefer container in this system is retrofitted with a set of heat exchange coils, namely a reefer container heat exchanger (e), added to the original reefer container evaporator, as shown in fig. 3 and 4. When the ship sails at sea and LNG fuel is consumed, under the action of the first circulating pump (7), the refrigerant A absorbs LNG cold energy in the first heat exchanger (5) and sequentially enters the refrigerated container through the liquid supply pipe (8), the inlet quick connector (d) and the electromagnetic valve (a), at the moment, the refrigerated container heat exchanger (e) is filled with the refrigerant A which absorbs the LNG cold energy, the original air cooler in the container works, and the refrigerant A releases the cold energy for refrigeration.

Furthermore, the inlet and the outlet of the heat exchange coil of the refrigerated container are respectively connected with the hose, the other end of the hose is respectively provided with an inlet quick connector (d) and an outlet quick connector (f), when the refrigerated container is loaded on a ship, the inlet quick connector (d) is in butt joint with the liquid supply pipe (8), and the outlet quick connector (f) is connected with the liquid return pipe (11).

Further, as shown in fig. 5 and 6, in the refrigerated container system and method using LNG cold energy of a ship according to the present invention, the liquid supply pipe (8) and the liquid return pipe (11) may be disposed on a lashing bridge of an LNG-powered container, and at the same time, in order to reduce the arrangement distance of the pipes, the refrigerated container may be centrally placed near the cabin of the ship, such as the areas a, B, C, and D in fig. 1, and more refrigerated container placement areas may be added according to actual situations.

The foregoing is merely a preferred embodiment of the present invention and the specific embodiments described herein are merely illustrative of the invention and are not intended to be limiting. It should be noted that modifications and adaptations may occur to those skilled in the art without departing from the principles of the present invention and should be considered within the scope of the present invention.

Claims

1. A system for utilizing ship LNG cold energy for a reefer container, characterized in that it comprises a transfer pump (1), an LNG fuel tank (2), a booster pump (3), a temperature control three-way valve (4), a first Heat exchanger (5), second heat exchanger (6), first circulation pump (7), liquid supply pipe (8), second circulation pump (9), third heat exchanger (10), liquid return Pipe (11), liquid return pipe temperature bulb (12), solenoid valve (a), temperature relay (b), temperature bulb (c), inlet quick connector (d), refrigerated container heat exchanger (e), outlet quick The joint (f), wherein the system for utilizing the cold energy of the ship LNG for a reefer container is further divided into: a cold energy utilization system for a reefer container, a supply pipeline system and an LNG fuel supply system. The supply pipeline system mainly includes: a first circulating pump (7), a liquid supply pipe (8), a liquid return pipe (11), and a liquid return pipe warm bulb (12), which is mainly used for conveying refrigerant A;

The LNG fuel supply system mainly includes: a transfer pump (1), an LNG fuel tank (2), a booster pump (3), a temperature control three-way valve (4), a first heat exchanger (5) and a cylinder jacket water Heating system. The LNG is transported from the LNG fuel tank (2) by the transfer pump (1), and is transported to the main power unit of the ship by the booster pump (3). After passing through the second heat exchanger (6), the circulation pipeline where the second circulating pump (9) is located is filled with refrigerant B, that is, a 40% ethylene glycol aqueous solution, which is used to heat the natural gas and make it reach the required level for combustion. The required temperature is 20°C to 45°C; or the LNG directly leads to the second heat exchanger (6) through the bypass loop of the temperature control three-way valve (4) without passing through the first heat exchanger.

The refrigeration container cold energy utilization system mainly includes: a solenoid valve (a), a temperature relay (b), a temperature bulb (c), an inlet quick connector (d), an outlet quick connector (e) and a refrigerated container heat exchanger (f) ), the main function of this system is to use the cold energy displaced from the LNG fuel for cargo refrigeration.

2. A system for utilizing cold energy of ship LNG for refrigerated containers according to claim 1, characterized in that: the refrigerated containers are different from traditional refrigerated containers, and the refrigerated containers in this system are located between the original air cooler and the evaporator. There is an additional set of heat exchange coils, namely the refrigerated container heat exchanger (e).

3. A system for utilizing cold energy of ship LNG for refrigerated containers according to claim 1, wherein the inlets and outlets of the heat exchange coils of the refrigerated containers are connected with hoses respectively, and the other ends of the hoses are respectively provided with Inlet quick connector (d) and outlet quick connector (f), when the reefer container is loaded on the ship, the inlet quick connector (d) of the inlet hose is connected with the liquid supply pipe (8), and the outlet quick connector of the outlet hose (f) Connect with the liquid return pipe (11).

4. A system method for utilizing cold energy of ship LNG for refrigerated containers, using the system in claim 1, characterized in that: when the ship is navigating at sea and LNG fuel is consumed, under the action of the first circulating pump (7) , the refrigerant A absorbs LNG cold energy in the first heat exchanger (5), and enters the refrigerated container through the liquid supply pipe (8), the inlet quick connector (d) and the solenoid valve (a) in turn. At this time, the refrigerated container exchanges heat The device (e) is filled with the refrigerant A that has absorbed the cold energy of LNG, the original air cooler in the container works, and the refrigerant A releases the cold energy for cooling. There is a temperature bulb (c) in the refrigerated container to sense the temperature. When the temperature in the container reaches the lower limit of the required refrigeration temperature, the signal will be transmitted to the temperature relay (b), and then the solenoid valve (a) will be controlled to close. Similarly , when the temperature in the container rises to the upper limit, the temperature bulb (c) can send a signal to the temperature relay (b), so as to control the solenoid valve (a) to open; when the ship is berthed without LNG fuel consumption, the reefer container will be as traditional as of refrigerated containers consume electricity for refrigeration.

5 . The method for utilizing the cold energy of ship LNG for a reefer container according to claim 4 , wherein the refrigerant A used in the supply pipeline system is a 50% ethylene glycol aqueous solution. 6 .

6. A method for utilizing the cold energy of ship LNG for a reefer container according to claim 4, characterized in that: the LNG exchanges heat with the refrigerant A in the supply pipeline system at the first heat exchanger (5), and the refrigerant A absorbs the cold energy released by the LNG, enters the supply pipeline system through the liquid supply pipe (8), and then enters the refrigerator cold energy utilization system through the inlet quick connector (d).

7. A method for utilizing ship LNG cold energy for a reefer container according to claim 4, characterized in that: the LNG pressurized by the booster pump (3) passes through the temperature-controlled three-way valve (4), and the temperature-controlled three-way The valve (4) is connected to the liquid return pipe temperature bulb (12) set near the liquid return pipe (11) of the first heat exchanger (5), and the side of the temperature control three-way valve (4) can be controlled according to the temperature. The flow of LNG through the pipeline. When the temperature of the liquid return pipe (11) is lower than -25°C, the valve of the LNG main pipe leading to the temperature control three-way valve (4) is closed, and at the same time, the valve of the bypass pipe is opened to the maximum, and the LNG does not undergo the first exchange. The heat exchanger (5) directly enters the second heat exchanger (6) through the bypass pipe, which can prevent the temperature in the pipeline from being too low, reaching the freezing point of refrigerant A, and blocking phenomenon; when the temperature of the return pipe is higher than - At 23°C, the LNG may partially or fully pass through the first heat exchanger (5).