Electric heating and cooling system for LNG (Liquefied Natural Gas) power-driven ship

Abstract

The utility model discloses an electric heating and cooling system for an LNG (Liquefied Natural Gas) power-driven ship. The power supply module comprises an evaporator, a turbine, a condenser, a generator and a first hot fluid circulation loop used for circulating first fluid, which are sequentially connected through a working medium pipeline to form a steam Rankine cycle loop; the heat supply module comprises a second hot fluid circulation loop and a hot water heat exchanger, the second hot fluid circulation loop is used for circulating first fluid, and the second hot fluid circulation loop is in fluid communication with the hot water heat exchanger; the cold supply module comprises a refrigerant pipeline used for circulating a refrigerant, a natural gas pipeline used for circulating natural gas and an LNG heat exchanger in fluid communication with the refrigerant pipeline; and the cooling water pipeline is used for circulating cooling water. Through the organic Rankine cycle power generation technology, the waste gas boiler technology and the LNG cold energy utilization technology, waste heat and waste cold of the ship are fully utilized, the energy utilization rate is increased, and environmental protection and energy conservation are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy-saving transformation of ships, and more specifically to an electric heating and cooling system for LNG (liquefied natural gas) powered ships. Background Art

[0002] With the implementation of programs such as the Energy Efficiency Design Index (EEDI), the Energy Efficiency Index (EEXI), the Carbon Intensity Index (CII), carbon intensity ratings, and enhanced ship energy efficiency management programs, there is an urgent need to reduce ship energy consumption and emissions. Therefore, more efficient energy recovery systems that can provide multiple energy forms have a positive impact on ship design and operation, and can also make a significant contribution to global energy conservation and emission reduction.

[0003] The thermal efficiency of existing marine engines is only around 50%, with most of the energy coming from high-temperature exhaust waste heat (such as that generated by burning natural gas) and jacket water waste heat. Marine waste heat utilization technology can effectively utilize this waste heat, converting it into electricity or meeting other heat needs. Exhaust gas boiler power generation technology is a common exhaust energy recovery technology in marine power systems. It has great flexibility and can adapt to exhaust energy recovery under different engine operating conditions. Despite this, the exhaust steam from the exhaust gas boiler still carries away some heat energy when passing through the condenser, resulting in heat energy waste.

[0004] In LNG-powered ships, LNG is gasified into natural gas to provide power for combustion in gas turbines. A large amount of cold energy is generated during the LNG gasification process, and this cold energy is often wasted.

[0005] At the same time, in addition to the demand for electricity, ships also have a demand for domestic hot water and refrigerated storage.

[0006] How to convert the above-mentioned wasted heat and cold energy into high-quality electricity, heat and cold energy required by ships, and further, to meet multiple energy needs at the same time without causing energy waste, and to ensure stable and safe system operation and high energy utilization rate, is a technical problem that urgently needs to be solved in this field. Utility Model Content

[0007] The purpose of this utility model is to provide an electric heating and cooling system for LNG-powered ships. This system addresses the issue of waste heat and cooling on ships, and combines the ship's needs for heat, cooling, and electricity. By leveraging organic Rankine cycle power generation technology, exhaust gas boiler technology, and LNG cooling energy utilization, it proposes a comprehensive ship heating and cooling energy generation system. This system fully utilizes the exhaust energy of ship engines and LNG cooling energy, simultaneously meeting multiple energy needs without wasting energy. The system operates stably and safely, improving energy utilization.

[0008] The utility model provides an electric heating and cooling system for LNG-powered ships, the system comprising:

[0009] a waste heat heat exchanger in which a first fluid is heated by waste heat from the LNG-powered ship;

[0010] a power supply module, the power supply module comprising an evaporator, a turbine, and a condenser connected in sequence through a working fluid pipeline to form a steam Rankine cycle, a generator, and a first thermal fluid circulation loop for circulating the first fluid; wherein the turbine is connected to the generator to drive the generator to generate electricity; a portion of the first thermal fluid circulation loop is disposed in the waste heat exchanger, and the first thermal fluid circulation loop is in fluid communication with the evaporator;

[0011] a heating module, the heating module comprising a second thermal fluid circulation loop for circulating the first fluid and a hot water heat exchanger, wherein a portion of the second thermal fluid circulation loop is disposed in the waste heat exchanger, and the second thermal fluid circulation loop is in fluid communication with the hot water heat exchanger;

[0012] a cooling module comprising a refrigerant pipeline for circulating refrigerant, a natural gas pipeline for circulating natural gas, and an LNG heat exchanger in fluid communication with the refrigerant pipeline, wherein the LNG heat exchanger reduces the temperature of the refrigerant circulating in the refrigerant pipeline by utilizing the latent heat of vaporization of LNG, thereby providing cooling to users through the refrigerant;

[0013] a cold water heat exchanger disposed on a refrigerant branch and in fluid communication with the refrigerant branch, the refrigerant branch being a branch of the refrigerant pipeline at the outlet side of the LNG heat exchanger; and

[0014] a cooling water pipeline for circulating cooling water, wherein the cooling water in the cooling water pipeline flows through the cold water heat exchanger, the condenser and the hot water heat exchanger in sequence;

[0015] The cooling water pipeline is in fluid communication with the cold water heat exchanger, and the cold water heat exchanger is used to cool the cooling water through the refrigerant after being cooled by the LNG heat exchanger; the cooling water pipeline is in fluid communication with the condenser, and the condenser is used to cool the working medium in the steam Rankine cycle loop through the cooling water; the cooling water pipeline is in fluid communication with the hot water heat exchanger, and the hot water heat exchanger is used to heat the cooling water through the first fluid heated by the waste heat exchanger, and supply heat to users through the heated cooling water.

[0016] In another preferred example, the first thermal fluid circulation loop and the second thermal fluid circulation loop together form a thermal fluid circulation loop.

[0017] In another preferred embodiment, when the evaporator is in operation, the first fluid absorbs the waste heat from the waste heat exchanger and is heated, and the heated first fluid releases heat to the working fluid in the power supply module through the evaporator;

[0018] When the condenser is in operation, the cooling water cools the working medium in the power supply module through the condenser.

[0019] In another preferred example, when the condenser is in operation and the cold water heat exchanger is enabled, the cooling water first passes through the cold water heat exchanger, where the refrigerant is cooled by the LNG heat exchanger, and the cooled cooling water passes through the condenser to cool the working fluid in the power supply module.

[0020] In another preferred embodiment, a working medium pump is provided on the working medium pipeline for driving the working medium to circulate in the steam Rankine cycle loop.

[0021] In another preferred example, a cooling water pump is provided on the cooling water pipeline for driving the cooling water to flow in the cooling water pipeline.

[0022] In another preferred example, a refrigerant pump is provided on the refrigerant pipeline for driving the refrigerant to flow in the refrigerant pipeline and the optional refrigerant branch.

[0023] In another preferred embodiment, the first thermal fluid circulation loop and the second thermal fluid circulation loop are two independent loops.

[0024] In another preferred example, a first thermal fluid pump is provided on the first thermal fluid circulation loop.

[0025] In another preferred embodiment, a second thermal fluid pump is provided on the second thermal fluid circulation loop.

[0026] In another preferred example, the first thermal fluid circulation loop and the second thermal fluid circulation loop partially overlap.

[0027] In another preferred embodiment, the pipelines of the first thermal fluid circulation loop and the second thermal fluid circulation loop near the waste heat exchanger overlap.

[0028] In another preferred example, the first thermal fluid circulation loop and the second thermal fluid circulation loop share a thermal fluid pump for driving the first fluid to flow in the first thermal fluid circulation loop and / or the second thermal fluid circulation loop.

[0029] In another preferred example, the first thermal fluid circulation loop and the second thermal fluid circulation loop overlap in the pipeline from the thermal fluid pump to the waste heat exchanger.

[0030] In another preferred example, the first fluid is oil.

[0031] In another preferred embodiment, the first fluid is thermal oil.

[0032] In another preferred embodiment, the cold water heat exchanger is only used in the power generation process.

[0033] In another preferred example, the cold water heat exchanger is optionally activated during the power generation process.

[0034] In another preferred embodiment, the cold water heat exchanger is used not only for power generation but also for regulating the amount of cooling supplied to users.

[0035] In another preferred example, the refrigerant exchanged through the cold water heat exchanger flows out through the refrigerant branch to provide cooling to users.

[0036] In another preferred example, the waste heat exchanger is an exhaust gas boiler, and part of the first thermal fluid circulation loop and / or the second thermal fluid circulation loop is arranged in the furnace of the exhaust gas boiler, wherein the exhaust gas with waste heat flows through the exhaust gas boiler from bottom to top, and the first fluid in the first thermal fluid circulation loop and / or the second thermal fluid circulation loop is heated by the waste heat of the exhaust gas in the exhaust gas boiler.

[0037] In another preferred example, a valve is provided on the first thermal fluid circulation loop connected to the evaporator, for controlling the conduction of the first thermal fluid circulation loop.

[0038] In another preferred example, an evaporator pre-valve is provided on the first thermal fluid circulation loop from the waste heat exchanger to the evaporator; and an evaporator post-valve is provided on the first thermal fluid circulation loop from the evaporator to the waste heat exchanger.

[0039] In another preferred example, the evaporator post-valve is arranged between the evaporator and the thermal fluid pump.

[0040] In another preferred example, the evaporator pre-valve is arranged between the evaporator and the junction of the first thermal fluid circulation loop and the second thermal fluid circulation loop.

[0041] In another preferred example, a hot water heat exchanger pre-valve is provided on the second thermal fluid circulation loop from the waste heat exchanger to the hot water heat exchanger; and a hot water heat exchanger post-valve is provided on the second thermal fluid circulation loop from the hot water heat exchanger to the waste heat exchanger.

[0042] In another preferred example, the hot water heat exchanger post-valve is arranged between the hot water heat exchanger and the thermal fluid pump.

[0043] In another preferred example, the hot water heat exchanger pre-valve is arranged between the hot water heat exchanger and the junction of the first thermal fluid circulation loop and the second thermal fluid circulation loop.

[0044] In another preferred example, a cold water heat exchanger pre-valve is provided on the refrigerant branch from the LNG heat exchanger to the cold water heat exchanger; and a cold water heat exchanger post-valve is provided on the refrigerant branch flowing out of the cold water heat exchanger.

[0045] In another preferred example, a refrigeration circuit valve is provided on the refrigerant pipeline flowing out of the LNG heat exchanger.

[0046] In another preferred example, the refrigerant branch flows from the refrigerant pipe to the cold water heat exchanger, and flows out of the cold water heat exchanger and back to the refrigerant pipe.

[0047] In another preferred example, a refrigeration circuit valve is provided on the refrigerant pipeline arranged in parallel with the refrigerant branch.

[0048] In another preferred example, when the system is powered on, the waste heat exchanger, the first thermal fluid circulation loop, the evaporator, the turbine, the condenser, the generator and the cooling water pipeline are in operation; optionally, the cold water heat exchanger, the LNG heat exchanger, the refrigerant pipeline, the refrigerant branch and the natural gas pipeline are in operation.

[0049] In another preferred example, when the system is in a heating state, the waste heat exchanger, the second thermal fluid circulation loop, the hot water heat exchanger and the cooling water pipeline are in operation.

[0050] In another preferred example, when the system is in a cooling state, the LNG heat exchanger, the refrigerant pipeline and the natural gas pipeline are in operation.

[0051] In another preferred embodiment, the system operates one, two or three of the above-mentioned power supply, heating and cooling at the same time.

[0052] The heat exchangers in this article are all surface heat exchangers.

[0053] The main advantages of this utility model include:

[0054] 1) By controlling the opening and closing of valves, the switching and adjustment of heating, electricity generation and combined heating and power generation can be realized flexibly and quickly.

[0055] 2) Make full use of the low-quality cold energy and heat energy generated by ship operation and convert them into high-quality thermoelectric cold energy to meet various energy needs and improve energy utilization.

[0056] 3) Compared with the traditional steam Rankine cycle, the present invention reduces the temperature of the cooling water end and improves the overall thermal efficiency of the cycle.

[0057] 4) Compared with the traditional direct exhaust of exhaust steam from exhaust gas boilers, the present invention reduces the final exhaust temperature, which is beneficial to reducing pollutant emissions.

[0058] 5) The supply ratio of heat, cooling and electricity is flexible and adjustable, which can adapt to various loads of engine operation and meet the matching requirements of a wider operating range.

[0059] More importantly, the present invention:

[0060] Thermal oil is used to exchange heat with exhaust gas, and then the thermal oil is used to generate circulating steam or heated water, rather than directly using an exhaust gas boiler to generate circulating steam or heated water. This makes the heat source more stable and less affected by the exhaust fluctuations of the main engine;

[0061] Compared with the solution of directly using LNG cold energy to exchange heat with the working fluid of the power supply module, which results in the working fluid of the power supply module being limited to fluids with extremely low melting points such as methane, ethane or ether liquid, the utility model uses refrigerant to recover LNG cold energy, and then exchanges heat with cooling water to form low-temperature cooling water. The low-temperature cooling water is used to cool the working fluid at the outlet of the Rankine cycle turbine. In this way, the working fluid in the power supply module of the utility model can still be selected from common safe working fluids such as steam, avoiding the use of flammable and explosive alkanes or toxic ether, thereby increasing the safety of the system.

[0062] Under the commonly used combined heat and power working conditions, the utility model preheats the cooling water by utilizing the heat after the turbine (heat released by the condenser), and then the preheated cooling water is heated by the heat transfer oil to supply hot water and provide heat energy to users, thus achieving full utilization of heat energy and saving energy and reducing consumption.

[0063] The power supply, heating and cooling conditions can be operated separately or in combination, and can be applied to various energy demands. Moreover, when each condition is operated separately, no waste of fuel or energy will be caused.

[0064] It should be understood that within the scope of the present invention, the above-mentioned technical features of the present invention and the technical features described in detail below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be listed here one by one. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0066] Figure 1 This is a system diagram of an electric heating and cooling system for an LNG-powered ship in an example of the present invention.

[0067] In the accompanying drawings, the following are marked:

[0068] 1- Exhaust gas boiler;

[0069] 2- evaporator;

[0070] 3-Turbine;

[0071] 4-Generator;

[0072] 5- condenser;

[0073] 6-working fluid pump;

[0074] 7-hot water heat exchanger;

[0075] 8-thermal oil pump;

[0076] 9-Cold water heat exchanger;

[0077] 10-LNG heat exchanger;

[0078] 11-evaporator pre-valve;

[0079] 12-evaporator rear valve;

[0080] 13-hot water heat exchanger pre-valve;

[0081] 14-Hot water heat exchanger rear valve;

[0082] 15-Cold water heat exchanger front valve;

[0083] 16-Cold water heat exchanger rear valve;

[0084] 17-Refrigeration circuit valve. DETAILED DESCRIPTION

[0085] After extensive and in-depth research and a large amount of screening, the inventors have developed for the first time an electric heating and cooling system for LNG-powered ships, which provides a ship's heat and cold energy comprehensive utilization power generation system. The utility model recovers heat energy and converts energy from ship engine exhaust, and recovers cold energy and converts energy from liquefied LNG, so as to supply the required heat, cooling and electricity needs for the ship: high heat utilization efficiency is achieved through direct heat exchange between ship exhaust and exhaust gas boiler exhaust steam; cold energy utilization is achieved through heat exchange between refrigerant and liquid LNG; exhaust gas heat is utilized through the evaporator and liquid LNG cold energy is utilized through the condenser to generate electricity through the Rankine cycle system; thereby meeting the ship's heating, cooling and electricity needs; and meeting multiple energy needs at the same time without causing energy waste; the system operates stably and safely, with high energy utilization rate. On this basis, the utility model was completed.

[0086] The utility model relates to the technical field of waste heat utilization of marine diesel engines, which mainly recovers part of the diesel engine exhaust and LNG cold energy to generate electricity through waste heat recovery, while recovering the remaining exhaust heat energy through waste gas boilers and other heat exchange components for heating, and uses LNG cold energy for refrigeration and ice making.

[0087] The utility model discloses a power generation system for comprehensive utilization of cold and heat energy, which mainly includes an exhaust gas boiler, an evaporator, a turbine, a generator, a condenser, a working fluid pump, a hot water heat exchanger, a thermal oil pump, an LNG heat exchanger and related valves.

[0088] The exhaust gas boiler, hot water heat exchanger, and thermal oil pump together form a thermal oil circuit, which exchanges the heat energy from the diesel engine exhaust with the thermal oil, which serves as a heat source with a certain temperature to provide energy for the steam turbine power generation system and hot water supply system.

[0089] The thermal oil circuit effectively reduces the impact of changes in exhaust temperature and flow on the steam Rankine power generation system and hot water supply system, thereby improving the overall operational stability of the system.

[0090] In the thermal oil circuit, low-temperature thermal oil is pumped to the exhaust gas boiler for heating to form high-temperature thermal oil, which is then transported to the evaporator and hot water heat exchanger through pipes and valves.

[0091] The high-temperature thermal oil entering the evaporator serves as the heat source for the Steam Rankine Cycle, exchanging heat with the water in the steam Rankine cycle loop, heating the water to steam while the thermal oil cools. The high-temperature thermal oil entering the hot water heat exchanger serves as the primary heat source for domestic water, heating the water to the required domestic temperature while the thermal oil cools. After cooling in the evaporator or hot water heat exchanger, the thermal oil is returned to the thermal oil pump, completing the entire thermal oil cycle.

[0092] The evaporator, turbine, generator, condenser and working medium pump jointly constitute a steam Rankine cycle power generation system, realize waste heat recovery, cold energy utilization and convert heat energy into electric energy output.

[0093] In the steam Rankine cycle power generation system, the working medium is in liquid state before entering the evaporator, and forms steam with certain temperature and pressure after heat exchange with the heat conducting oil in the evaporator. The steam enters the turbine and drives the impeller to rotate to do work, drives the coaxial generator to generate electricity and outputs electric power. The working medium after doing work is in low pressure and temperature, forms exhaust steam and enters the condenser. The exhaust steam is heat exchanged in the condenser and transfers the remaining heat to the cooling water, so that the temperature of the cooling water rises, and the exhaust steam is condensed into liquid state. The condensate water returns to the working medium pump and is transported to the evaporator by the working medium pump, so that the whole steam Rankine cycle loop is completed.

[0094] The hot water supply system mainly consists of the condenser and the hot water heat exchanger. The cooling water at normal temperature enters the system through the external water pump, is heat exchanged with the refrigerant after the cold water heat exchanger, and the temperature of the cooling water is lowered. Then the cooling water enters the condenser, absorbs the heat of the exhaust steam in the steam Rankine cycle, the temperature rises, and the preheating effect is achieved. The preheated cooling water enters the hot water heat exchanger and is heated again by the higher temperature heat conducting oil, and hot water meeting the temperature requirement is formed and transported to the user end for use.

[0095] The refrigeration supply system consists of the LNG heat exchanger and the cold water heat exchanger. The refrigerant enters the system through the external working medium pump, absorbs a large amount of cold energy through the LNG heat exchanger, and LNG is gasified, and the temperature of the refrigerant is lowered. Then it enters the cold water heat exchanger and exchanges heat with the cooling water at normal temperature, and the temperature of the cooling water is lowered. Finally, the refrigerant is transported out of other refrigeration demand ends to meet the refrigeration demand of the user.

[0096] Valves are arranged before and after the evaporator, hot water heat exchanger, cold water heat exchanger and refrigeration circuit, a total of seven valves, which form a heat source distribution valve group. The adjustment of the heat source distribution valve group can realize the control of electric energy and hot water, and meet the change of the demand of the user for electricity and heat.

[0097] The adjustment of the heat source distribution valve group can realize the following four types of working modes.

[0098] A. Refrigeration mode: when the user has no demand for electric energy and hot water, the valves before and after the evaporator, hot water heat exchanger and cold water heat exchanger are closed, and the refrigeration circuit valve is opened, so that the LNG cold energy is recovered by the refrigerant, and is used for the refrigeration system of the ship.

[0099] B. Heating mode: when the electric energy supply of the user is sufficient and only has a certain demand for hot water, the valves before and after the evaporator, cold water heat exchanger and refrigeration circuit are closed, and the valves before and after the hot water heat exchanger are opened, so that the heat conducting oil of the exhaust gas boiler flows through the hot water heat exchanger and heats the cooling water.

[0100] C. Power Generation Mode: When the user has sufficient hot water supply and only has a certain demand for electricity, the valves before and after the hot water heat exchanger can be closed, the valves before and after the evaporator and optionally the cold water heat exchanger can be opened, and the refrigeration circuit valve can be closed. This allows all the heat transfer oil from the exhaust gas boiler to flow through the evaporator, heating the water in the steam Rankine cycle and completing the power generation work.

[0101] D. Cogeneration mode: When users have certain demands for both hot water and electricity, the opening of each valve in the heat source distribution valve group can be adjusted according to the actual demand conditions to achieve free regulation of the entire cold and heat energy recovery system.

[0102] This utility model recovers waste heat from ship diesel engines through an exhaust gas boiler, utilizes LNG cold energy through a refrigerant, and completes the recovery and conversion of electricity and heat through a Rankine cycle, a hot water supply system, and a refrigeration supply system, forming a ship heat and cold energy comprehensive utilization power generation system. This utility model has the following advantages:

[0103] 1) By using the exhaust gas boiler to exchange heat with the engine flue gas and using thermal oil as the system's heat source, the entire waste heat recovery system operates more stably and can be flexibly adjusted based on engine exhaust conditions. This also prevents damage to the exhaust gas boiler and other equipment from directly impacting the steam Rankine cycle and hot water supply system.

[0104] 2) The heat and cold source distribution valve group allows the system to distribute the heat source and cold source according to the user's demand for heat, electricity and cold.

[0105] 3) The hot water supply system recovers the residual heat of the exhaust steam in the steam Rankine cycle by using the condenser to heat the cooling water. The hot water is then heated by the hot water heater to obtain hot water that meets the usage requirements. The use of secondary heating reduces the heat loss of the steam Rankine cycle and improves the overall thermal efficiency of the system.

[0106] 4) The refrigeration supply system uses the LNG cold energy absorbed by the refrigerant to exchange heat with the cooling water about to enter the steam Rankine cycle, thereby reducing the temperature of the cooling water entering the steam Rankine cycle, reducing the temperature of the cold source, and improving the overall thermal efficiency of the system.

[0107] 5) The power generation system adopts the steam Rankine cycle, which has a simple structure, high power generation efficiency and a wide range of system applications.

[0108] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. Furthermore, the accompanying drawings are schematic diagrams, and therefore the devices and apparatus of the present invention are not limited by the dimensions or proportions of the schematic diagrams.

[0109] It should be noted that in the claims and description of this patent, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "including a" does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0110] Example

[0111] The electric heating and cooling system for LNG powered ships in this embodiment is as follows Figure 1 The system includes an exhaust gas boiler 1, an evaporator 2, a turbine 3, a generator 4, a condenser 5, a working fluid pump 6, a hot water heat exchanger 7, a thermal oil pump 8, a cold water heat exchanger 9, an LNG heat exchanger 10, an evaporator pre-valve 11, an evaporator post-valve 12, a hot water heat exchanger pre-valve 13, a hot water heat exchanger post-valve 14, a cold water heat exchanger pre-valve 15, a cold water heat exchanger post-valve 16, and a refrigeration circuit valve 17.

[0112] The thermal oil is heated to high temperature by exhaust gas boiler 1. At the outlet of exhaust gas boiler 1, the high-temperature oil is connected via a tee to the evaporator pre-valve 11 and the hot water heat exchanger pre-valve 13, respectively. The outlet of evaporator pre-valve 11 is connected to the thermal oil inlet of evaporator 2, serving as the heat source for the Rankine cycle. The thermal oil outlet of evaporator 2 is connected to the inlet of evaporator post-valve 12. The outlet of hot water heat exchanger pre-valve 13 is connected to the inlet of hot water heat exchanger 7, serving as the primary heat source for hot water. The thermal oil outlet of hot water heat exchanger 7 is connected to the inlet of hot water heat exchanger post-valve 14. The outlets of evaporator post-valve 12 and hot water heat exchanger post-valve 14 converge via a tee and are connected to the inlet of thermal oil pump 8. The outlet of thermal oil pump 8 is connected to the inlet of exhaust gas boiler 1, completing the thermal oil circulation loop.

[0113] In the steam Rankine cycle power generation system, in the evaporator 2, the working fluid absorbs heat from the thermal oil heated by the exhaust gas boiler 1 and vaporizes into working fluid steam. The working fluid outlet of the evaporator 2 is connected to the inlet of the turbine 3, supplying it with working fluid steam. After performing work, exhaust steam is formed, which flows out from the outlet of the turbine 3. The outlet of the turbine 3 is connected to the working fluid inlet of the condenser 5. In the condenser 5, the exhaust steam preheats the low-temperature cooling water. The working fluid outlet of the condenser 5 is connected to the inlet of the working fluid pump 6. The outlet of the working fluid pump 6 is connected to the working fluid inlet of the evaporator 2. The steam Rankine cycle loop is formed by the drive of the working fluid pump 6.

[0114] Normal temperature cooling water is transported by the cooling water pump to the water inlet of the cold water heat exchanger 9, and forms low-temperature cooling water through heat exchange with the refrigerant in the cold water heat exchanger; the outlet of the cold water heat exchanger 9 is connected to the inlet of the condenser 5, and the low-temperature cooling water is preheated (heated once) in the condenser 5. It should be noted that the above steps are optional and only exist in the mode of simultaneous power supply and heat supply. The outlet of the condenser 5 is connected to the inlet of the hot water heat exchanger 7. The (preheated) cooling water is heated (secondarily) in the hot water heat exchanger, and flows out of the water outlet of the hot water heat exchanger 7 and is transported to the user end for heating.

[0115] The refrigerant is delivered to the inlet of the LNG heat exchanger 10 via an external working fluid pump, where it exchanges heat with liquid LNG and absorbs the cold energy of the LNG to become a low-temperature refrigerant. Optionally, the low-temperature refrigerant is connected to the inlet of the cold water heat exchanger pre-valve 15 and the inlet of the refrigeration circuit valve 17 via a three-way pipe via the outlet of the LNG heat exchanger 10; the outlet of the cold water heat exchanger pre-valve 15 is connected to the refrigerant inlet of the cold water heat exchanger 9, where the low-temperature refrigerant exchanges heat with normal temperature cooling water; the refrigerant outlet of the cold water heat exchanger 9 is connected to the inlet of the cold water heat exchanger post-valve 16; the outlet of the cold water heat exchanger post-valve 16 merges with the outlet of the refrigeration circuit valve 17 and is delivered to the cooling user end via a three-way pipe.

[0116] The turbine 3 can be a centripetal turbine, an axial flow turbine or a mixed flow turbine, and different forms can be selected according to actual working medium, pressure, temperature and flow rate.

[0117] The evaporator 2, condenser 5, hot water heat exchanger 7, cold water heat exchanger 9, and LNG heat exchanger 10 can adopt various forms, such as shell and tube type, plate type, etc.

[0118] Preferably, the evaporator pre-valve 11, the hot water heat exchanger pre-valve 13, the cold water heat exchanger pre-valve 15, and the refrigeration circuit valve 17 can use adjustable butterfly valves, and the evaporator post-valve 12, the hot water heat exchanger post-valve 14, and the cold water heat exchanger post-valve 16 can use switch-type stop valves to achieve better control effect.

[0119] Working modes include:

[0120] A. Cooling Mode: Close evaporator pre-valve 11, evaporator post-valve 12, hot water heat exchanger pre-valve 13, hot water heat exchanger post-valve 14, cold water heat exchanger pre-valve 15, and cold water heat exchanger post-valve 16. Open refrigeration circuit valve 17. Turn off thermal oil pump 8 and working fluid pump 6. The entire system does not provide heat or electricity; it only absorbs LNG cold energy through the refrigerant and supplies it externally.

[0121] B. Heating Mode: Close evaporator pre-valve 11, evaporator post-valve 12, cold water heat exchanger pre-valve 15, and cold water heat exchanger post-valve 16; open hot water heat exchanger pre-valve 13 and hot water heat exchanger post-valve 14; start thermal oil pump 8; and shut down working fluid pump 6. This allows all thermal oil to pass through hot water heat exchanger 7 for heat exchange, generating hot water that meets the requirements and is then supplied to the outside.

[0122] C. Power Generation Mode: Close the hot water heat exchanger pre-valve 13, hot water heat exchanger post-valve 14, and refrigeration circuit valve 17; open the evaporator pre-valve 11, evaporator post-valve 12, cold water heat exchanger pre-valve 15, and cold water heat exchanger post-valve 16; start the thermal oil pump 8; and start the working fluid pump 6. This allows the thermal oil to pass entirely through the evaporator 2 for heat exchange, while the cooling water passes through the cold water heat exchanger 9 to generate low-temperature cooling water, completing the steam Rankine cycle for energy conversion and electrical energy output. The water outlet of the condenser 5 will still produce relatively low-temperature hot water, which can be bypassed and not delivered to the user.

[0123] D. Cogeneration mode: The evaporator pre-valve 11, the hot water heat exchanger pre-valve 13, and the cold water heat exchanger pre-valve 15 are open; the refrigeration circuit valve 17 is closed; the thermal oil pump 8 is turned on; the working fluid pump 6 is turned on; the evaporator post-valve 12, the hot water heat exchanger post-valve 14, and the cold water heat exchanger post-valve 16 are adjusted in opening according to actual demand or operating status to control the supply ratio of hot water, electricity, and cooling.

[0124] This embodiment further improves the thermal efficiency of the entire system by recycling heat from high-temperature exhaust gas and jacket water. It also further achieves energy conservation, emission reduction, and improved energy efficiency by recycling the cold energy generated during the LNG vaporization process. Instead of directly using an exhaust gas boiler to generate circulating steam or heated water, thermal oil is used to exchange heat with the exhaust gas, resulting in a more stable heat source that is less affected by fluctuations in the main engine exhaust. Compared to solutions that directly utilize LNG cold energy for heat exchange with the power generation module working fluid, which is limited to fluids with extremely low melting points such as methane, ethane, or ether, this embodiment uses a refrigerant to recover LNG cold energy, which is then exchanged with cooling water to generate low-temperature cooling water. This low-temperature cooling water is then used to cool the working fluid at the outlet of the Rankine cycle turbine. This allows the working fluid in the power supply module of this embodiment to remain a common and safe working fluid, such as steam, avoiding the use of flammable and explosive alkanes or toxic ether, thereby enhancing system safety. Under the more common combined heat and power (CHP) operating conditions, this embodiment utilizes post-turbulence heat (heat released by the condenser) to preheat cooling water. This preheated cooling water is then heated by thermal oil to supply hot water, providing thermal energy to users. This fully utilizes thermal energy and reduces energy consumption. The power, heating, and cooling modes can operate independently or in combination to meet various energy needs. Even when each mode is operated independently, no fuel or energy is wasted.

[0125] All documents mentioned in this application are incorporated herein by reference, just as if each document were incorporated herein by reference individually. It should also be understood that after reading the above teachings of this application, those skilled in the art may make various changes or modifications to this application, and that such equivalents also fall within the scope of the claims appended hereto.

Claims

1. An electric heating and cooling system for LNG powered ships, characterized in that: The system comprises: a waste heat heat exchanger in which a first fluid is heated by waste heat from the LNG-powered ship; a power supply module, the power supply module comprising an evaporator, a turbine, and a condenser connected in sequence through a working fluid pipeline to form a steam Rankine cycle, a generator, and a first thermal fluid circulation loop for circulating the first fluid; wherein the turbine is connected to the generator to drive the generator to generate electricity; a portion of the first thermal fluid circulation loop is disposed in the waste heat exchanger, and the first thermal fluid circulation loop is in fluid communication with the evaporator; a heating module, the heating module comprising a second thermal fluid circulation loop for circulating the first fluid and a hot water heat exchanger, wherein a portion of the second thermal fluid circulation loop is disposed in the waste heat exchanger, and the second thermal fluid circulation loop is in fluid communication with the hot water heat exchanger; a cooling module comprising a refrigerant pipeline for circulating refrigerant, a natural gas pipeline for circulating natural gas, and an LNG heat exchanger in fluid communication with the refrigerant pipeline, wherein the LNG heat exchanger reduces the temperature of the refrigerant circulating in the refrigerant pipeline by utilizing the latent heat of vaporization of LNG, thereby providing cooling to users through the refrigerant; a cold water heat exchanger disposed on a refrigerant branch and in fluid communication with the refrigerant branch, the refrigerant branch being a branch of the refrigerant pipeline at the outlet side of the LNG heat exchanger; and a cooling water pipeline for circulating cooling water, wherein the cooling water in the cooling water pipeline flows through the cold water heat exchanger, the condenser and the hot water heat exchanger in sequence; The cooling water pipeline is in fluid communication with the cold water heat exchanger, and the cold water heat exchanger is used to cool the cooling water through the refrigerant after being cooled by the LNG heat exchanger; the cooling water pipeline is in fluid communication with the condenser, and the condenser is used to cool the working medium in the steam Rankine cycle loop through the cooling water; the cooling water pipeline is in fluid communication with the hot water heat exchanger, and the hot water heat exchanger is used to heat the cooling water through the first fluid heated by the waste heat exchanger, and supply heat to users through the heated cooling water.

2. The system according to claim 1, wherein When the evaporator is in operation, the first fluid absorbs the waste heat from the waste heat exchanger and is heated, and the heated first fluid releases heat to the working fluid in the power supply module through the evaporator; When the condenser is in operation, the cooling water cools the working medium in the power supply module through the condenser.

3. The system according to claim 2, wherein: When the condenser is in operation and the cold water heat exchanger is enabled, the cooling water first passes through the cold water heat exchanger, where the refrigerant is cooled by the LNG heat exchanger. The cooled cooling water then passes through the condenser to cool the working fluid in the power supply module.

4. The system according to claim 1, wherein A working medium pump is provided on the working medium pipeline for driving the working medium to circulate in the steam Rankine cycle loop.

5. The system according to claim 1, wherein: The first thermal fluid circulation loop and the second thermal fluid circulation loop share a thermal fluid pump for driving the first fluid to flow in the first thermal fluid circulation loop and / or the second thermal fluid circulation loop.

6. The system according to claim 1, wherein: The cold water heat exchanger is optionally activated during power generation.

7. The system according to claim 1, wherein: The waste heat exchanger is an exhaust gas boiler, and part of the first thermal fluid circulation loop and / or the second thermal fluid circulation loop is arranged in the furnace of the exhaust gas boiler, wherein the exhaust gas with waste heat flows through the exhaust gas boiler from bottom to top, and the first fluid in the first thermal fluid circulation loop and / or the second thermal fluid circulation loop is heated in the exhaust gas boiler by the waste heat of the exhaust gas.

8. The system according to any one of claims 1 to 7, wherein: When the system is powered on, the waste heat exchanger, the first thermal fluid circulation loop, the evaporator, the turbine, the condenser, the generator and the cooling water pipeline are in operation; optionally, the cold water heat exchanger, the LNG heat exchanger, the refrigerant pipeline, the refrigerant branch and the natural gas pipeline are in operation.

9. The system according to any one of claims 1 to 7, wherein: When the system is in a heating state, the waste heat exchanger, the second thermal fluid circulation loop, the hot water heat exchanger and the cooling water pipeline are in operation.

10. The system according to any one of claims 1 to 7, wherein: When the system is in a cooling state, the LNG heat exchanger, the refrigerant pipeline, and the natural gas pipeline are in operation.

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