Liquefied natural gas (LNG) power device for ship

Abstract

The utility model provides a ship LNG (Liquefied Natural Gas) power device. The ship LNG power device comprises a combustion system, a heat exchange system, a cold machine system and a heat machine system, the combustion system comprises a vaporizer used for vaporizing liquefied natural gas and an engine used for receiving natural gas of the vaporizer. The heat exchange system is connected with the vaporizer so that heat in the heat exchange agent can be transmitted into the vaporizer to vaporize the liquefied natural gas. The cold machine system can heat the heat supply agent and can input heat of the heat supply agent into the heat exchange system so as to heat the heat exchange agent; the cooling liquid is used for absorbing heat of the engine; the cooling liquid can transfer heat into the heat exchange system so as to heat the heat exchange agent. When the ship is started, the operation of the heat exchange system, the cold machine system and the heat machine system can be controlled to ensure that heat in the heat exchange agent continuously and stably heats the liquefied natural gas, so that the liquefied natural gas is safely and reliably vaporized to form the natural gas.

Description

TECHNICAL FIELD

[0001] The utility model relates to ship power technology field especially relates to a ship LNG power device. BACKGROUND

[0002] LNG (Liquefied Natural Gas, liquefied natural gas) ship uses liquefied natural gas as main fuel to drive ship navigation.Compared with traditional fuel ship, LNG ship has the advantages of low carbon environmental protection, high efficiency, economy etc.

[0003] The liquid natural gas in LNG ship is generally heated by electric heating equipment when using, to make liquid natural gas temperature rise and vaporization form natural gas.But there is energy waste between fuel-power-heat conversion, and electric heating equipment is prone to failure to cause temperature uncontrollable, increase the security risk of power device. UTILITARY MODEL CONTENT

[0004] The purpose of the present application is to provide a kind of ship LNG power device with high energy utilization efficiency, good safety.

[0005] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0006] According to one aspect of the present application, the present application provides a kind of ship LNG power device, it includes: combustion system, heat exchange system, cold machine system and heat engine system;Combustion system includes vaporizer and engine;The vaporizer is used to vaporize liquid natural gas into natural gas;The engine is communicated with the vaporizer, and the engine is used to receive the natural gas and combustion work;Heat exchange agent flows in heat exchange system, and the heat exchange system is connected with the vaporizer, to be able to transmit the heat in the heat exchange agent to the liquid natural gas in the vaporizer vaporization;Heat agent flows in the interior of cold machine system, and the cold machine system can heat the heat agent, and can input the heat of the heat agent to the heat exchange system, to heat the heat exchange agent;Cooling liquid flows in heat engine system, and the cooling liquid is used to absorb the heat of the engine;The cooling liquid can transmit heat to the heat exchange system, to heat the heat exchange agent.

[0007] In some embodiments, the heat exchange system includes first heat exchanger and second heat exchanger connected in communication, the first heat exchanger is located upstream of the second heat exchanger;The first heat exchanger is connected with the cold machine system, to make the heat exchange agent pass through the first heat exchanger and absorb the heat of the heat agent;The second heat exchanger is connected with the vaporizer, and is located upstream of the vaporizer;The second heat exchanger is connected with the heat engine system, to make the heat exchange agent pass through the second heat exchanger and absorb the heat in the cooling liquid.

[0008] In some embodiments, the cooling system comprises a heating circuit and a transfer circuit; the heat supply agent comprises a first heat supply agent and a second heat supply agent; the first heat supply agent flows in the heating circuit; the heating circuit is capable of evaporating the first heat supply agent and then compressing the first heat supply agent to form high-temperature steam; the second heat supply agent flows in the transfer circuit, the transfer circuit is connected with the heating circuit and the heat exchange system, and the second heat supply agent is capable of absorbing heat in the high-temperature steam and transferring the heat to the heat exchange agent.

[0009] In some embodiments, the transfer circuit comprises at least one transfer heat exchanger; the heating circuit comprises an evaporator and at least one compressor connected in sequence, the evaporator is capable of evaporating the first heat supply agent to form steam, and the compressor is capable of compressing the steam to form high-temperature steam, and the compressor is located upstream of the adjacent transfer heat exchanger to enable the high-temperature steam to be input into the transfer heat exchanger to exchange heat with the second heat supply agent.

[0010] In some embodiments, the transfer circuit further comprises a transfer liquid storage tank and a transfer liquid driving pump, the transfer liquid storage tank is connected with the transfer heat exchanger, and the transfer liquid storage tank is used for containing the second heat supply agent; the transfer liquid driving pump is arranged between the transfer liquid storage tank and the transfer heat exchanger to pump the second heat supply agent in the transfer liquid storage tank into the transfer heat exchanger.

[0011] In some embodiments, the transfer circuit further comprises a plurality of transfer temperature sensors, and the plurality of transfer temperature sensors are respectively arranged upstream and downstream of the first heat exchanger, and the transfer temperature sensors are used for acquiring temperature information of the second heat supply agent.

[0012] In some embodiments, the heat engine system further comprises a cooling structure and an engine temperature sensor, the cooling structure is arranged on the engine, and the cooling structure flows with the cooling liquid; the cooling structure is connected with the second heat exchanger to input the cooling liquid into the second heat exchanger; the engine temperature sensor is arranged between the cooling structure and the second heat exchanger, and the engine temperature sensor is used for detecting temperature information of the cooling liquid output by the cooling structure.

[0013] In some embodiments, the heat exchange system further comprises a heat exchange liquid storage tank and a heat exchange liquid driving pump, the heat exchange liquid storage tank is arranged between the second heat exchanger and the vaporizer, and the heat exchange liquid storage tank is used for storing the heat exchange agent; the heat exchange liquid driving pump is arranged at an output end of the heat exchange liquid storage tank to output the heat exchange agent in the heat exchange liquid storage tank to the vaporizer.

[0014] In some embodiments, the heat exchange system is provided with a first control valve, the cold machine system is provided with a second control valve, and the heat machine system is provided with a third control valve; the power device further comprises a controller electrically connected with the first control valve, the second control valve and the third control valve, so as to control the on-off of the first control valve, the second control valve and the third control valve.

[0015] In some embodiments, the combustion system further comprises a normal-temperature transfer tank for accommodating the liquid natural gas and warming the liquid natural gas; the normal-temperature transfer tank is connected with an input end of the vaporizer, so as to input the stored liquid natural gas into the vaporizer for vaporization; and / or, the combustion system further comprises a pressure stabilizer and a gas-liquid separator; the pressure stabilizer is connected with an output end of the vaporizer, so as to receive the natural gas vaporized and output by the vaporizer; and the gas-liquid separator is connected with an output end of the pressure stabilizer, so as to separate residual liquid natural gas in the natural gas.

[0016] From the above technical solutions, the present application has at least the following advantages and positive effects:

[0017] In the present application, when the ship is started, the operation of the heat exchange system, the cold machine system and the heat machine system can be controlled, so as to ensure that the heat in the heat transfer agent continuously and stably heats the liquid natural gas, so that the liquid natural gas is safely and reliably vaporized to form natural gas, avoiding the uncontrollable temperature caused by directly heating the liquid natural gas by the electric heater in the related art, reducing the safety hazard of the power device. Moreover, the power device recovers the heat generated by the engine during combustion through the heat machine system, improves the energy utilization efficiency of the power device, and avoids waste of energy. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structural schematic view of the power device of the present application.

[0019] The reference signs are explained as follows: 100, combustion system; 101, storage tank; 102, normal-temperature transfer tank; 103, vaporizer; 104, pressure stabilizer; 105, gas-liquid separator; 106, engine; 121, first fuel valve; 122, second fuel valve; 123, third fuel valve; 131, first stop valve; 132, second stop valve; 141, first fuel pump; 142, second fuel pump; 200, heat exchange system; 201, first heat exchanger; 202, second heat exchanger; 203, heat exchange storage tank; 211, heat exchange drive liquid pump; 212, first control valve; 213, first pressure relief valve; 214, heat exchange temperature sensor; 300, cold machine system; 310, transfer loop; 311, third heat exchanger; 312, fourth heat exchanger; 313, transfer storage tank; 314, transfer drive liquid pump; 315, second control valve; 316, transfer temperature sensor; 317, second pressure relief valve; 320, heating loop; 321, evaporator; 322, compressor; 323, throttle valve; 400, hot machine system; 401, cooling structure; 411, engine temperature sensor; 412, third control valve; 413, cooling drive liquid pump; 414, third pressure relief valve. DETAILED DESCRIPTION

[0020] Typical embodiments embodying the features and advantages of the present application will now be described in detail. It should be understood, however, that the application can be practiced in various ways and that the description and drawings are not intended to limit the application in any way.

[0021] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0022] LNG (Liquefied Natural Gas) ships use liquefied natural gas as the main fuel to drive the ship to sail.

[0023] In the related art, the LNG ship directly heats the liquid natural gas into natural gas by using an electric heater, which is prone to cause unstable heating temperature, and the electric heating equipment is prone to failure, resulting in uncontrollable temperature and increasing the safety hazard of the power device.

[0024] Referring to Figure 1 The ship LNG power device provided in the present application comprises a combustion system 100, a heat exchange system 200, a cold machine system 300, and a hot machine system 400. The combustion system 100 comprises a vaporizer 103 and an engine 106. The vaporizer 103 is used to vaporize the liquid natural gas into natural gas. The engine 106 is connected with the vaporizer 103, and the engine 106 is used to receive the natural gas and do work by combustion. The heat exchange system 200 circulates a heat exchange agent, and the heat exchange system 200 is connected with the vaporizer 103, so as to be able to transfer the heat in the heat exchange agent to the vaporized liquid natural gas in the vaporizer 103. The cold machine system 300 circulates a heat supply agent. The cold machine system 300 is able to heat the heat supply agent, and is able to input the heat of the heat supply agent into the heat exchange system 200, so as to heat the heat exchange agent. The hot machine system 400 circulates a cooling liquid, and the cooling liquid is used to absorb the heat of the engine 106. The cooling liquid is able to transfer the heat to the heat exchange system 200, so as to heat the heat exchange agent.

[0025] When the ship LNG power device (hereinafter referred to as the power device) starts, the operation of the heat exchange system 200, the cold machine system 300, and the hot machine system 400 can be controlled, so that the heat exchange system 200 is able to absorb the heat in the cold machine system 300 and the hot machine system 400. After absorbing the heat, the heat exchange agent in the heat exchange system 200 is able to transfer the heat to the vaporizer 103, so as to continuously and stably heat the liquid natural gas, so that the liquid natural gas is safely and reliably vaporized into natural gas, avoiding the uncontrollable temperature caused by directly heating the liquid natural gas by using the electric heater in the related art, and effectively reducing the safety hazard of the power device.

[0026] In addition, the power device is able to recover the heat generated by the engine 106 during combustion work through the hot machine system 400, improve the energy utilization efficiency of the power device, and avoid waste of energy.

[0027] Referring to Figure 1 In the present embodiment, the power device comprises the vaporizer 103 and the engine 106. The vaporizer 103 is able to vaporize the liquid natural gas into natural gas. The engine 106 is located downstream of the vaporizer 103, so as to be able to receive the natural gas output by the vaporizer 103 and do work by combustion, thereby driving the ship to move.

[0028] In some embodiments, the vaporizer 103 can be a shell-and-tube vaporizer 103 or a plate-type vaporizer 103.

[0029] In some embodiments, the vaporizer 103 can include a first vaporization input end, a second vaporization input end, a first vaporization output end, and a second vaporization output end. The first vaporization input end can be connected to a gas source of liquid natural gas, so as to input the liquid natural gas into the vaporizer 103. The first vaporization output end can be connected to the engine 106, so as to output the natural gas into the engine 106. The second vaporization input end can be connected to the heat exchange system 200, so as to input the heat exchange agent into the vaporizer 103. The second vaporization output end can be used to output the heat exchange agent after being exchanged with the liquid natural gas in the vaporizer 103.

[0030] Referring to Figure 1 In the embodiment, the combustion system 100 can further include a storage tank 101, which is used to store the liquid natural gas, and the storage tank 101 is the gas source of the liquid natural gas.

[0031] In some embodiments, the storage tank 101 can be an external structure, and the vaporizer 103 can be detachably connected to the storage tank 101.

[0032] Referring to Figure 1 In the embodiment, the combustion system 100 can further include a normal-temperature transfer tank 102. The normal-temperature transfer tank 102 is connected to the storage tank 101, and is used to contain the liquid natural gas output by the storage tank 101. The normal-temperature transfer tank 102 can exchange heat with the external environment, so as to warm the contained liquid natural gas, thereby reducing the heat required for subsequent vaporization of the vaporizer 103 and improving the vaporization efficiency of the liquid natural gas. The normal-temperature transfer tank 102 is connected to the input end of the vaporizer 103, so as to input the stored liquid natural gas into the vaporizer 103 for vaporization.

[0033] In addition, the cold energy released by the normal-temperature transfer tank 102 can be used for refrigeration of a refrigeration chamber and a living and working space, so as to improve the energy utilization efficiency of the power device.

[0034] Referring to Figure 1 In the embodiment, the combustion system 100 can further include a pressure stabilizer 104 and a gas-liquid separator 105. The pressure stabilizer 104 is connected to the output end of the vaporizer 103, so as to receive the natural gas output by the vaporization of the vaporizer 103. The pressure stabilizer 104 can stabilize the pressure of the natural gas and ensure smooth flow. The gas-liquid separator 105 is connected to the output end of the pressure stabilizer 104, so as to separate the residual liquid natural gas in the natural gas. The gas-liquid separator 105 can deliver the separated natural gas into the engine 106, so as to avoid the liquid hydrocarbon or water entering into the engine 106, thereby making the combustion and work of the engine 106 more stable and prolonging the service life of the engine 106.

[0035] In some embodiments, the gas-liquid separator 105 can be connected with the storage tank 101, the normal-temperature transfer tank 102 or the vaporizer 103, so as to return the separated liquid natural gas to the storage tank 101, the normal-temperature transfer tank 102 or the vaporizer 103, to realize the reuse of the liquid natural gas and improve the resource utilization efficiency of the power device.

[0036] In other embodiments, the gas-liquid separator 105 can be connected with other devices outside the system, so as to deliver the separated liquid natural gas to the devices outside the system.

[0037] Referring to Figure 1 In the embodiment, the fuel system further comprises a plurality of fuel valves, which are respectively arranged upstream and / or downstream of the normal-temperature transfer tank 102, the vaporizer 103 and the pressure stabilizer 104, so as to facilitate the operation and stop of each functional device.

[0038] The plurality of fuel valves comprises a first fuel valve 121 arranged between the storage tank 101 and the normal-temperature transfer tank 102, a second fuel valve 122 arranged between the normal-temperature transfer tank 102 and the vaporizer 103, and a third fuel valve 123 arranged between the vaporizer 103 and the pressure stabilizer 104. The first fuel valve 121, the second fuel valve 122 and the third fuel valve 123 can be used to respectively open and close the storage tank 101, the normal-temperature transfer tank 102, the vaporizer 103 and the pressure stabilizer 104, so as to facilitate the replacement and maintenance of the individual functional devices.

[0039] In some embodiments, the fuel valves can be electric valves.

[0040] In some embodiments, the gas-liquid separator 105 further comprises a plurality of stop valves, which are used to adjust the flow rate of the liquid natural gas delivered to the downstream functional devices. In addition, the stop valves can also prevent the reverse flow of the liquid and gas, to play a role in safety protection.

[0041] The plurality of stop valves comprises a first stop valve 131 arranged at the output end of the normal-temperature transfer tank 102 and a second stop valve 132 arranged at the output end of the vaporizer 103. The first stop valve 131 can be used to adjust the flow rate of the liquid natural gas input from the normal-temperature transfer tank 102 to the vaporizer 103. The second stop valve 132 can be used to adjust the flow rate of the natural gas output from the vaporizer 103 to the pressure stabilizer 104.

[0042] In some embodiments, the stop valves can be electric valves.

[0043] Referring to Figure 1 In the embodiment, the heat exchange system 200 further comprises a plurality of fuel pumps, which are respectively arranged downstream of the functional devices, so as to pump the liquid in the upstream functional devices into the downstream functional devices.

[0044] The plurality of fuel pumps include a first fuel pump 141 and a second fuel pump 142. The first fuel pump 141 is located downstream of and in communication with the storage tank 101 to pump the liquid natural gas in the storage tank 101 into the normal-temperature intermediate tank 102. The second fuel pump 142 is located downstream of and in communication with the normal-temperature intermediate tank 102 to pump the liquid natural gas in the normal-temperature intermediate tank 102 into the vaporizer 103.

[0045] Referring to Figure 1 In the embodiment, the power device further includes a heat exchange system 200. The heat exchange system 200 is configured to absorb heat from the cold machine system 300 and the heat machine system 400 and to transfer the heat to the combustion system 100 to vaporize the liquid natural gas into natural gas.

[0046] The heat exchange system 200 includes a first heat exchanger 201 and a second heat exchanger 202 in communication. The first heat exchanger 201 is located upstream of the second heat exchanger 202. The first heat exchanger 201 is connected to the cold machine system 300 to allow the heat exchange agent to absorb heat from the heat supply agent through the first heat exchanger 201. The second heat exchanger 202 is connected to the vaporizer 103 and is located upstream of the vaporizer 103. The second heat exchanger 202 is connected to the heat machine system 400 to allow the heat exchange agent to absorb heat from the cooling liquid through the second heat exchanger 202. The heat exchange agent in the second heat exchanger 202 is output to the vaporizer 103 to allow the heat exchange agent to exchange heat with the liquid natural gas through the vaporizer 103.

[0047] In some embodiments, the first heat exchanger 201, the second heat exchanger 202, and the vaporizer 103 are sequentially connected end to end to form a closed loop, so that the heat exchange agent can circulate in the closed loop, thereby improving the use efficiency of the heat exchange agent and reducing the use cost.

[0048] In some embodiments, the first heat exchanger 201 and the second heat exchanger 202 can be tube-in-shell heat exchangers or plate heat exchangers.

[0049] In other embodiments, the first heat exchanger 201 can include a first heat exchange input end, a first heat exchange output end, a second heat exchange input end, and a second heat exchange output end. The first heat exchange input end can be in communication with the second vaporization output end of the vaporizer 103 to input the heat-exchanged heat exchange agent in the vaporizer 103 into the first vaporizer 103. The first heat exchange output end can be in communication with the second heat exchanger 202 to input the heat exchange agent in the first heat exchanger 201 into the second heat exchanger 202. The second heat exchange input end and the second heat exchange output end can be connected to the cold machine system 300 to input the heat supply agent into the first heat exchanger 201, thereby facilitating heat exchange between the heat exchange agent and the heat supply agent.

[0050] In some embodiments, the second heat exchanger 202 can be configured to receive the heat exchange medium from the first heat exchanger 201 and output the heat exchange medium to the vaporizer 103 after the heat exchange medium exchanges heat with the heat engine system 400.

[0051] The second heat exchanger 202 also includes a first heat exchange input end, a first heat exchange output end, a second heat exchange input end, and a second heat exchange output end. The first heat exchange input end of the second heat exchanger 202 can be in communication with the first heat exchange output end of the first heat exchanger 201. The first heat exchange output end of the second heat exchanger 202 can be in communication with the input end of the vaporizer 103. The second heat exchange input end and the second heat exchange output end of the second heat exchanger 202 can be connected to the heat engine system 400 for inputting the cooling liquid into the second heat exchanger 202 to facilitate the heat exchange between the heat exchange medium and the cooling liquid.

[0052] Referring to Figure 1 In the present embodiment, the heat exchange system 200 is provided with a first control valve 212. The first control valve 212 is arranged downstream of the second heat exchanger 202. The first control valve 212 is capable of controlling the on-off between the second heat exchanger 202 and the vaporizer 103, thereby controlling the start and stop of the heat exchange system 200 and improving the operation efficiency of the heat exchange system 200.

[0053] In some embodiments, the first control valve 212 can be an electric valve.

[0054] Referring to Figure 1 In the present embodiment, the heat exchange system 200 further includes a heat exchange liquid storage tank 203 and a heat exchange liquid driving pump 211. The heat exchange liquid storage tank 203 is arranged between the second heat exchanger 202 and the vaporizer 103 and is used to store the heat exchange medium output by the second heat exchanger 202. The heat exchange liquid driving pump 211 is arranged at the output end of the heat exchange liquid storage tank and is used to output the heat exchange medium in the heat exchange liquid storage tank 203 to the vaporizer 103.

[0055] The heat exchange liquid storage tank 203 is used to accommodate the heat exchange medium output by the second heat exchanger 202, and the heat exchange liquid driving pump 211 is used to output the heat exchange medium in the heat exchange liquid storage tank 203 to the vaporizer 103. On the one hand, this can ensure that the pressure of the heat exchange medium output by the heat exchange system 200 is stable, thereby avoiding the problem of low vaporization efficiency of the liquid natural gas caused by too little heat exchange medium input into the vaporizer 103. On the other hand, this can also enable the heat exchange medium to mix in the heat exchange liquid storage tank 203, thereby ensuring that the temperature of the output heat exchange medium is uniform, facilitating the monitoring and control of the heat exchange system 200, and ensuring the vaporization efficiency and stability of the vaporizer 103.

[0056] Referring to Figure 1In the embodiment, the heat exchange system 200 further comprises a first pressure relief valve 213. The first pressure relief valve 213 is arranged between the heat exchange working fluid pump 211 and the vaporizer 103, and is used for discharging part of the heat exchange agent output by the heat exchange working fluid pump 211, so as to avoid that the pressure of the heat exchange agent input into the vaporizer 103 is too large to damage the vaporizer 103, and avoid that the flow rate of the heat exchange agent input into the vaporizer 103 is too fast to cause low heat exchange efficiency and poor heat transfer uniformity.

[0057] Referring to Figure 1 In the embodiment, the heat exchange system 200 further comprises a heat exchange temperature sensor 214. The heat exchange temperature sensor 214 is arranged downstream of the vaporizer 103, and is used for detecting the temperature of the heat exchange agent output by the vaporizer 103, so as to obtain the temperature information of the heat exchange agent, thereby facilitating the staff to control the start and stop of the combustion system 100, the heat exchange system 200, the cold engine system 300 and the hot engine system 400, and improving the working efficiency of the power device.

[0058] In some embodiments, the heat exchange temperature sensor 214 can be arranged between the vaporizer 103 and the first heat exchanger 201, so as to obtain the temperature of the heat exchange agent after passing through the vaporizer 103, thereby facilitating the staff to judge the vaporization effect of the vaporizer 103 according to the temperature of the heat exchange agent.

[0059] Referring to Figure 1 In the embodiment, the power device can further comprise a cold engine system 300. The cold engine system 300 is connected with the first heat exchanger 201, so that the heat supply agent can enter the first heat exchanger 201 to exchange heat with the heat exchange agent, thereby causing the heat exchange agent to absorb heat and increase in temperature. The cold engine system 300 can be started alone according to the running state of the engine 106 or the demand of the staff, and can also be started mixedly with the hot engine system 400, so as to guarantee that the power device can stably, safely and reliably run under various working conditions.

[0060] The cold engine system 300 comprises a heating circuit 320 and a transfer circuit 310. The heat supply agent comprises a first heat supply agent and a second heat supply agent. The first heat supply agent flows in the heating circuit 320. The heating circuit 320 can evaporate and then compress the first heat supply agent to form high-temperature steam. The second heat supply agent flows in the transfer circuit 310, and the transfer circuit 310 is connected with the heating circuit 320 and the heat exchange system 200. The second heat supply agent can absorb heat in the high-temperature steam and transfer the heat to the heat exchange agent, so that the second heat supply agent can stably and uniformly heat the heat exchange agent, and guarantee that the temperature of the heat exchange agent after being heated is uniform.

[0061] In some embodiments, the transfer circuit 310 comprises at least one transfer heat exchanger. The structure of the transfer heat exchanger can be arranged in the same manner as the structure of the first heat exchanger 201.

[0062] The second heat supply agent flows through the heat transfer exchanger. The heat transfer exchanger can include a first heat transfer input end, a first heat transfer output end, a second heat transfer input end, and a second heat transfer output end. The first heat transfer input end can be connected to the second heat exchange output end of the first heat exchanger 201, and the first heat transfer output end can be connected to the second heat exchange input end of the first heat exchanger 201, so that a closed loop is formed between the heat transfer exchanger and the first heat exchanger 201, thereby facilitating the circulation of the second heat supply agent in the heat transfer exchanger and the first heat exchanger 201, and improving the use efficiency of the second heat supply agent. The second heat transfer input end and the second heat transfer output end can be connected to the heating circuit 320, so that the first heat supply agent can flow into the heat transfer exchanger to exchange heat with the second heat supply agent, thereby increasing the temperature of the second heat supply agent.

[0063] In some embodiments, the heat transfer circuit 310 can include two heat transfer exchangers. The two heat transfer exchangers are a third heat exchanger 311 and a fourth heat exchanger 312. The third heat exchanger 311, the fourth heat exchanger 312, and the first heat exchanger 201 are sequentially connected end to end, so that a closed loop is formed between the third heat exchanger 311, the fourth heat exchanger 312, and the first heat exchanger 201, thereby facilitating the circulation of the second heat supply agent in the third heat exchanger 311, the fourth heat exchanger 312, and the first heat exchanger 201, achieving multi-stage heating of the second heat supply agent, improving the heating effect of the second heat supply agent, and ensuring the use efficiency of the second heat supply agent.

[0064] The first heat transfer output end of the third heat exchanger 311 is in communication with the first heat transfer input end of the fourth heat exchanger 312, the first heat transfer output end of the fourth heat exchanger 312 is in communication with the second heat exchange input end of the first heat exchanger 201, and the second heat exchange output end of the first heat exchanger 201 is in communication with the first heat transfer input end of the third heat exchanger 311, thereby forming a closed loop.

[0065] In other embodiments, the heat transfer circuit 310 can include three heat transfer exchangers or four heat transfer exchangers connected in series, to achieve multi-stage heating of the second heat supply agent.

[0066] Referring to Figure 1 In this embodiment, the heat transfer circuit 310 further includes a heat transfer liquid storage tank 313 and a heat transfer liquid pump 314. The heat transfer liquid storage tank 313 is in communication with the heat transfer exchanger, and the heat transfer liquid storage tank 313 is used to store the second heat supply agent. The heat transfer liquid pump 314 is arranged between the heat transfer liquid storage tank 313 and the heat transfer exchanger, to pump the second heat supply agent in the heat transfer liquid storage tank 313 into the heat transfer exchanger, thereby being able to control the amount of second heat supply agent input into the heat transfer exchanger, and ensuring the safety of the heat transfer exchanger.

[0067] In some embodiments, the delivery liquid tank 313 is arranged between the first heat exchanger 201 and the third heat exchanger 311. The input end of the delivery liquid tank 313 is connected to the second heat exchange output end of the first heat exchanger 201, and the output end of the delivery liquid tank 313 is connected to the first delivery input end of the third heat exchanger 311. The delivery liquid tank 313 is used to store the second heat medium output by the first heat exchanger 201, so as to uniformly supply the second heat medium to the delivery heat exchanger through the delivery liquid pump 314, and ensure stable and reliable operation of the delivery circuit 310.

[0068] Referring to Figure 1 In the embodiment, the delivery circuit 310 further comprises a plurality of delivery temperature sensors 316. The plurality of delivery temperature sensors 316 are arranged upstream and downstream of the first heat exchanger 201, respectively. The delivery temperature sensors 316 are used to detect and obtain temperature information of the second heat medium, so as to facilitate the staff to adjust the working state of the heating circuit 320 according to the temperature information of the second heat medium.

[0069] In some embodiments, the delivery circuit 310 comprises two delivery temperature sensors 316. One of the two delivery temperature sensors 316 is arranged between the first heat exchanger 201 and the delivery liquid tank 313, and is used to obtain temperature information of the second heat medium output by the first heat exchanger 201. The other of the two delivery temperature sensors 316 is arranged between the fourth heat exchanger 312 and the first heat exchanger 201, and is used to obtain temperature information of the second heat medium input to the first heat exchanger 201 by the fourth heat exchanger 312. The staff can adjust the working state of the refrigerator system 300 in real time according to the temperature information of the two delivery temperature sensors 316, so as to adjust the heat exchange efficiency of the first heat exchanger 201.

[0070] Referring to Figure 1 In the embodiment, the refrigerator system 300 is provided with a second control valve 315 for controlling the start and stop of the refrigerator system 300. The second control valve 315 can be arranged on the delivery circuit 310, so as to control the on-off of the delivery circuit 310, thereby realizing the start and stop of the refrigerator system 300.

[0071] In some embodiments, the second control valve 315 is arranged between the first heat exchanger 201 and the delivery liquid tank 313. In other embodiments, the second control valve 315 can be an electric valve.

[0072] Referring to Figure 1 In the embodiment, the delivery circuit 310 further comprises a second pressure relief valve 317. The second pressure relief valve 317 is arranged between the first heat exchanger 201 and the delivery liquid tank 313, and is used to release the second heat medium in the delivery circuit 310, so as to ensure stable and reliable operation of the delivery circuit 310.

[0073] In some embodiments, the second pressure relief valve 317 is arranged between the first heat exchanger 201 and the second control valve 315, so that when the second control valve 315 is closed, the second pressure relief valve 317 can release part of the second heat supply agent, avoiding the second heat supply agent output by the fourth heat exchanger 312 from impacting and damaging the first heat exchanger 201, and ensuring the safety and stability of the transfer circuit 310.

[0074] Referring to Figure 1 In the present embodiment, the heating circuit 320 includes an evaporator 321 and at least one compressor 322 connected in sequence. The evaporator 321 can evaporate the first heat supply agent to form steam, and the compressor 322 can compress the steam to form high-temperature steam. The compressor 322 is located upstream of the adjacent transfer heat exchanger, so that the high-temperature steam can be input into the transfer heat exchanger to exchange heat with the second heat supply agent. The heating circuit 320 generates heat through the evaporator 321 and the compressor 322, avoiding the safety hazards that may be caused by electric heaters, thereby effectively ensuring the safety and reliability of the heating circuit 320, and enabling the heating circuit 320 to generate heat stably and uniformly.

[0075] In some embodiments, the heating circuit 320 includes an evaporator 321 and one compressor 322. The transfer circuit 310 includes a third heat exchanger 311. The output end of the evaporator 321 is connected to the input end of the compressor 322, and the output end of the compressor 322 is connected to the second transfer input end of the third heat exchanger 311, so that the high-temperature steam output by the compressor 322 can exchange heat with the second heat supply agent, thereby heating the second heat supply agent.

[0076] In some embodiments, the heating circuit 320 includes an evaporator 321 and two compressors 322. The transfer circuit 310 includes a third heat exchanger 311 and a fourth heat exchanger 312. The output end of the evaporator 321 is connected to the input end of one of the compressors 322, and the output end of the compressor 322 is connected to the second transfer input end of the third heat exchanger 311, so that high-temperature steam is input into the third heat exchanger 311 to exchange heat with the second heat supply agent. The second transfer output end of the third heat exchanger 311 is connected to the input end of the other compressor 322, which compresses the steam again to form high-temperature steam. The output end of the other compressor 322 is connected to the second transfer input end of the fourth heat exchanger 312, so that the high-temperature steam formed by the second compression is input into the fourth heat exchanger 312 to exchange heat with the second heat supply agent, thereby performing multi-stage heating on the second heat supply agent, increasing the temperature of the second heat supply agent, increasing the temperature of the heat exchange agent in the heat exchange system 200, and improving the vaporization efficiency of the vaporizer 103.

[0077] In some embodiments, the heating circuit 320 comprises an evaporator 321 and two compressors 322. The transfer circuit 310 comprises a third heat exchanger 311. The evaporator 321, the two compressors 322 and the third heat exchanger 311 are connected in series. The evaporator 321 and the two compressors 322 perform multi-stage compression on the steam to form high-temperature steam, thereby increasing the temperature of the high-temperature steam to improve the heat exchange efficiency of the third heat exchanger 311.

[0078] Referring to Figure 1 In the present embodiment, the evaporator 321, the compressor 322 and the transfer heat exchanger are connected in series to form a closed loop, and the first heat transfer agent circulates in the closed loop, thereby effectively reducing the heating cost of the heating circuit 320.

[0079] Referring to Figure 1 In the present embodiment, the heating circuit 320 further comprises a throttle valve 323. The throttle valve 323 is arranged upstream of the evaporator 321 to control the flow rate of the input into the evaporator 321 and control the evaporation efficiency of the evaporator 321. Moreover, the throttle valve 323 can prevent the first heat transfer agent from impacting the evaporator 321, thereby ensuring the safety and stability of the evaporator 321.

[0080] In some embodiments, the throttle valve 323 can be an electric throttle valve 323 to adjust the flow rate of the first heat transfer agent according to the demand.

[0081] In some embodiments, the throttle valve 323 is arranged between the second transfer output end of the fourth heat exchanger 312 and the input end of the evaporator 321 to adjust the flow rate of the first heat transfer agent input into the evaporator 321 from the fourth heat exchanger 312, thereby preventing liquid from impacting the evaporator 321 and ensuring the safety and stability of the evaporator 321.

[0082] Referring to Figure 1 In the present embodiment, the heat engine system 400 further comprises a cooling structure 401 and an engine temperature sensor 411. The cooling structure 401 is arranged on the engine 106, and cooling liquid flows through the cooling structure 401 to absorb heat generated by the engine 106 during operation. The cooling structure 401 is connected to the second heat exchanger 202 to input the cooling liquid into the second heat exchanger 202. The engine temperature sensor 411 is arranged between the cooling structure 401 and the second heat exchanger 202. The engine temperature sensor 411 is located on the second heat exchange output end of the second heat exchanger 202. The engine temperature sensor 411 is used to detect the temperature information of the cooling liquid output by the cooling structure 401.

[0083] The power device can control the start and stop of the cooling system 300 and the heat engine system 400 according to whether the temperature information obtained by the engine temperature sensor 411 reaches a preset standard.

[0084] When the temperature information obtained by the engine temperature sensor 411 reaches the first preset standard, the engine 106 is in a high-temperature state, and the refrigerant circulating in the cooling structure 401 heats the heat transfer agent through the second heat exchanger 202 after absorbing the heat of the engine 106, so that the heat in the engine 106 vaporizes the liquid natural gas through the heat exchange system 200. At this time, the power device is in a heat engine working mode, the cooling system 300 is stopped, and the heat engine system 400, the heat exchange system 200 and the combustion system 100 are started, so as to fully utilize the waste heat of the engine 106 and reduce the use cost of the power device. And it can reduce the starting time of the power device and improve the use experience.

[0085] The temperature of the second preset standard is lower than that of the first preset standard. The parameters of the first preset standard and the second preset standard can be preset according to the actual size of the engine 106, the heat transfer efficiency of the engine 106, the fuel combustion efficiency and the like.

[0086] When the temperature information obtained by the engine temperature sensor 411 does not reach the second preset standard, the engine 106 is in a low-temperature state, the heat engine system 400 is stopped, and the cooling system 300 and the heat exchange system 200 are started to vaporize the liquid natural gas. At this time, the power device is in a cooling working mode, which ensures the safe and stable operation of the power device.

[0087] When the temperature information obtained by the engine temperature sensor 411 reaches the second preset standard but does not reach the first preset standard, the heat of the engine 106 absorbed by the cooling structure 401 is not enough to fully vaporize the liquid natural gas. At this time, the power device is in a mixed working mode, and the heat engine system 400, the cooling system 300 and the heat exchange system 200 are started to improve the temperature of the heat transfer agent, so that the liquid natural gas is fully vaporized, thereby reducing the use cost of the power device.

[0088] Referring to Figure 1 In the embodiment, the heat engine system 400 is provided with a third control valve 412. The third control valve 412 is used to control the start and stop of the heat engine system 400.

[0089] In some embodiments, the third control valve 412 is arranged on the output end of the cooling structure 401, and is used to control the output of the cooling liquid in the cooling structure 401.

[0090] In some embodiments, the third control valve 412 is an electric valve.

[0091] In some embodiments, the engine 106 in the power device of the ship is a large fuel engine 106. When the fuel inside the engine 106 burns to do work, the heat generated by the fuel combustion is transmitted slowly, so that the overall temperature of the engine 106 rises slowly.

[0092] When the overall temperature of the engine 106 is low, the low-temperature environment also affects the combustion of the fuel, resulting in incomplete combustion. The power device can disconnect the heat engine system 400 through the third control valve 412 to avoid the cooling liquid absorbing the heat of the engine 106, so that the engine 106 can be started stably and reliably, and the combustion efficiency of the fuel is improved.

[0093] Referring to Figure 1 In this embodiment, the heat engine system 400 further comprises a cooling liquid pump 413. The cooling liquid pump 413 is arranged between the cooling structure 401 and the second heat exchanger 202. The cooling liquid pump 413 is in communication with the output end of the cooling structure 401 and the second heat input end of the second heat exchanger 202, so as to be able to pump the cooling liquid in the cooling structure 401 into the second heat exchanger 202, so that the cooling liquid exchanges heat with the heat transfer agent. The cooling liquid pump 413 can adjust the pumping speed of the cooling liquid, so as to be able to adjust the heat exchange efficiency of the cooling liquid and the heat transfer agent.

[0094] Referring to Figure 1 In this embodiment, the heat engine system 400 further comprises a third pressure relief valve 414. The third pressure relief valve 414 is arranged at the input end of the cooling structure 401, so as to be able to discharge part of the cooling liquid, avoid the cooling liquid output by the second heat exchanger 202 from impacting and damaging the first heat exchanger 201, and ensure the safety and stability of the heat engine system 400.

[0095] Referring to Figure 1 In this embodiment, the power device further comprises a controller (not shown in the figure). The controller can be electrically connected with the heat exchange temperature sensor 214, the transmission temperature sensor 316 and the engine temperature sensor 411, so as to be able to obtain the temperature information of the heat transfer agent, the second heat transfer agent and the cooling liquid.

[0096] The controller is electrically connected with the first control valve 212, the second control valve 315 and the third control valve 412, so as to be able to control the on-off of the first control valve 212, the second control valve 315 and the third control valve 412, thereby being able to control the start-stop of the heat exchange system 200, the cooling engine system 300 and the heat engine system 400.

[0097] In some embodiments, the controller can also be electrically connected with the pressure stabilizer 104, the gas-liquid separator 105, the first fuel valve 121, the second fuel valve 122, the third fuel valve 123, the first fuel pump 141 and the second fuel pump 142, so as to be used for controlling the operation of the combustion system 100 and adjusting the amount of natural gas input into the engine 106.

[0098] In some embodiments, the controller is further electrically connected with the heat exchange medium pump 211, so as to control the flow efficiency of the heat exchange medium in the heat exchange system 200, thereby controlling the vaporization efficiency of the liquid natural gas.

[0099] In some embodiments, the controller is further electrically connected with the evaporator 321, the compressor 322 and the throttle valve 323, so as to control the heating efficiency of the heating circuit 320.

[0100] In some embodiments, the controller is further electrically connected with the cooling medium pump 413, so as to adjust the flow of the cooling medium pumped by the cooling medium pump 413, to adjust the cooling efficiency of the engine 106 and the heat exchange efficiency of the second heat exchanger 202 and the heat exchange medium.

[0101] The above embodiments are only illustrative of the structures, and the structures in the embodiments are not fixedly combined. In the absence of structural conflicts, the structures in the embodiments can be combined arbitrarily.

[0102] Referring to Figure 1 The application provides a ship LNG power device. When the power device is started, the temperature information of the cooling medium in the hot engine system 400 is detected by the engine temperature sensor 411, so as to control the operation of the heat exchange system 200, the cold engine system 300 and the hot engine system 400 respectively, and the power device can be switched flexibly between the cold engine working mode, the hot engine working mode and the mixed mode, so as to improve the energy utilization efficiency of the power device.

[0103] In addition, when the power device is in the cold engine working mode, the hot engine working mode or the mixed working mode, the heat exchange medium in the heat exchange system 200 is continuously and stably heated by using the waste heat of the engine 106 and the steam re-compression technology, so that the liquid natural gas is safely and reliably vaporized to form natural gas, and the uncontrollable temperature problem caused by directly heating the liquid natural gas by the electric heater in the related art is avoided, and the safety hazard of the power device is reduced.

[0104] Referring to ​ The application also provides a control method of a ship LNG power device. The control method is used for controlling the ship LNG power device according to any one of the above. The control method comprises the following steps.

[0105] In step S110, the cold engine system 300 can heat the heat supply agent, and the heat supply agent can heat the heat exchange medium.

[0106] In step S120, the cooling medium in the hot engine system 400 can absorb the heat generated when the engine 106 burns and works, and the heat is transferred to the heat exchange medium.

[0107] In step S200, the heat exchanger in the heat exchanger system 200 is heated, and the heat exchanger can exchange heat with the liquid natural gas through the vaporizer 103 to heat and vaporize the liquid natural gas into natural gas and deliver the natural gas to the engine 106 for combustion.

[0108] When the ship starts, the cold machine system 300 and / or the heat machine system 400 starts, and the heat exchanger system 200 starts, the heat exchanger can receive heat from the cold machine system 300 and the heat machine system 400 and exchange heat with the liquid natural gas in the vaporizer 103 to continuously and stably heat the liquid natural gas in the heat exchanger, thereby ensuring that the liquid natural gas is safely and reliably vaporized into natural gas, and the natural gas is stably and safely input into the engine 106 for combustion.

[0109] In addition, the power device recovers the heat generated by the engine 106 during combustion through the heat machine system 400, improves the energy utilization efficiency of the power device, and avoids waste of energy.

[0110] In this embodiment, the heat machine system 400 is provided with an engine temperature sensor 411 for detecting the temperature information of the cooling liquid after flowing through the engine 106. The power device further comprises a controller electrically connected with the engine temperature sensor 411 to obtain the detected temperature information of the cooling liquid. The controller can be electrically connected with the cold machine system 300, the heat machine system 400, the heat exchanger system 200, and the combustion system 100.

[0111] The control method further comprises step S130.

[0112] In step S130, the cold machine system 300, the heat exchanger system 200, and the combustion system 100 can be started to form a cold machine working mode; the cold machine system 300, the heat machine system 400, the heat exchanger system 200, and the combustion system 100 can be started to form a mixed working mode; the heat machine system 400, the heat exchanger system 200, and the combustion system 100 can be started to form a heat machine working mode; and the controller can control the switching of the cold machine working mode, the mixed working mode, and the heat machine working mode according to the temperature information of the engine temperature sensor 411.

[0113] When the controller controls the power device to switch between the cold machine working mode, the heat machine working mode, and the mixed working mode according to the temperature information obtained by the engine temperature sensor 411, the waste heat of the engine 106 can be effectively utilized, the energy utilization efficiency of the power device is improved, and the operating cost of the ship is reduced.

[0114] In the embodiment, the temperature of the marine engine 106 gradually decreases to normal temperature when the marine engine 106 is not used for a long time. At this time, the engine 106 needs to enter the cold engine working mode to vaporize the liquid natural gas to provide fuel for the engine 106 before switching from the cold engine working mode to the hybrid working mode and finally switching to the hot engine working mode.

[0115] The controller is pre-configured with the first preset standard and the second preset standard.

[0116] The step S130 further includes a step S131.

[0117] In step S131, when the power device is started, the controller controls the hot engine system 400 and the heat exchange system 200 to start; the controller detects the temperature information of the cooling liquid through the engine temperature sensor 411; when the temperature of the cooling liquid does not reach the second preset standard, the power device is switched to the cold engine working mode.

[0118] When the power device is started, the controller controls the hot engine system 400 and the heat exchange system 200 to start first, so that the cooling liquid flows in the hot engine system 400 and exchanges heat with the heat exchange agent in the heat exchange system 200.

[0119] The controller can detect the temperature information of the cooling liquid through the engine temperature sensor 411; when the temperature of the cooling liquid tends to be stable and the temperature of the cooling liquid is lower than the second preset standard, the controller controls the power device to switch to the cold engine working mode.

[0120] When the power device is in the cold engine working mode, on the one hand, the cooling liquid can avoid absorbing the heat generated when the engine 106 is started to affect the starting efficiency of the engine 106, so that the fuel in the engine 106 can be fully combusted; on the other hand, the liquid natural gas can be fully vaporized to improve the resource utilization efficiency.

[0121] In some embodiments, in the embodiment, the cold engine system 300 includes a heating circuit 320 and a transfer circuit 310. The heat supply agent includes a first heat supply agent flowing in the heating circuit 320 and a second heat supply agent flowing in the transfer circuit 310. The heating circuit 320 includes at least one compressor 322. The transfer circuit 310 includes a transfer temperature sensor 316 for acquiring the temperature information of the second heat supply agent before and after heat exchange in the first heat exchanger 201. The controller is electrically connected with the transfer temperature sensor 316 to acquire the temperature difference information of the second heat supply agent according to the temperature information of the second heat supply agent before and after heat exchange in the first heat exchanger 201.

[0122] The step S130 further includes a step S132.

[0123] In step S132, the controller can acquire the temperature difference information of the second heat supply agent before and after heat exchange in the first heat exchanger 201 through the passing temperature sensor 316, and dynamically adjust the power of the compressor 322 according to the temperature difference information to adjust the temperature of the first heat supply agent and the second heat supply agent.

[0124] When the controller detects the temperatures of the second heat exchange input end and the second heat exchange output end of the first heat exchanger 201 through the passing temperature sensor 316, the temperature information of the second heat supply agent before and after passing through the first heat exchanger 201 can be acquired, and the temperature difference information of the second heat supply agent when passing through the first heat exchanger 201 can be acquired by combining the two temperature information.

[0125] After the controller acquires the temperature difference information of the second heat supply agent, the power of the compressor 322 can be dynamically adjusted to adjust the temperature of the first heat supply agent. The change of the temperature of the first heat supply agent will cause the temperature of the second heat supply agent to change. The change of the temperature of the second heat supply agent will affect the temperature of the heat exchange agent. When the temperature of the heat exchange agent in the heat exchange system 200 reaches the preset temperature, the combustion system 100 is started to vaporize the liquid natural gas in the vaporizer 103, so as to ensure the vaporization efficiency of the liquid natural gas and adjust the combustion efficiency of the combustion system 100.

[0126] In addition, the heat exchange agent is heated by the steam re-compression technology, so as to transfer heat to the liquid natural gas in the vaporizer 103 to vaporize the liquid natural gas, which effectively avoids the problem of uncontrollable temperature and easy safety hazards caused by directly heating the liquid natural gas by the electric heater in the related art.

[0127] In this embodiment, step S130 further includes step S133.

[0128] In step S133, when the power device is in the cold machine working mode, the hot machine system 400 is started every interval of the preset time. When the hot machine system 400 is started, the controller can detect whether the temperature of the cooling liquid reaches the second preset standard through the engine temperature sensor 411. When the temperature of the cooling liquid does not reach the second preset standard, the hot machine system 400 stops running. When the temperature of the cooling liquid reaches the second preset standard, the controller controls the power device to switch to the mixed working mode, and the cold machine system 300, the hot machine system 400, the heat exchange system 200 and the combustion system 100 are started to run.

[0129] When the engine 106 is running in the cold mode, the temperature of the engine 106 gradually increases. When the heat engine system 400 is temporarily started, the engine temperature sensor 411 detects that the temperature of the coolant reaches the second preset standard and does not reach the first preset standard, the controller controls the heat engine system 400 to continue to start, so that the power device is switched from the cold mode to the hybrid mode, so as to make full use of the heat generated by the engine 106 during combustion and improve the energy utilization rate of the ship during operation.

[0130] When the heat engine system 400 is temporarily started, the engine temperature sensor 411 detects that the temperature of the coolant does not reach the second preset standard, the controller controls the heat engine system 400 to be closed, so that the power device remains in the cold mode.

[0131] When the heat engine system 400 is closed for a preset time, the controller controls the heat engine system 400 to be temporarily started again to detect whether the temperature of the coolant reaches the second preset standard.

[0132] In the embodiment, step S130 further includes step S134.

[0133] Step S134, when the engine temperature sensor 411 detects that the temperature of the coolant reaches the first preset standard, the controller controls the power device to be switched to the heat mode, and the heat engine system 400, the heat exchange system 200 and the combustion system 100 are started and run, and the cold system 300 is stopped.

[0134] When the engine 106 works for a period of time, the temperature of the engine 106 rises to the first preset standard, the controller controls the ship power device to be switched to the heat mode, so as to make full use of the waste heat generated by the engine 106 during work, improve the energy utilization efficiency, and reduce the use cost of the ship. And can reduce the temperature of the engine 106, guarantee the stable and safe operation of the engine 106.

[0135] In the embodiment, step S134 further includes step S1341.

[0136] Step S1341, when the engine temperature sensor 411 detects that the temperature of the coolant reaches the first preset standard, the controller controls the compressor 322 to gradually reduce the power, and when the power of the compressor 322 is reduced to the following, the cold system 300 is stopped, and the power device is switched to the heat mode.

[0137] When the power device switches from the hybrid working mode to the thermal engine working mode, the controller controls the compressor 322 to gradually reduce the power until the power of the compressor 322 is reduced to below the preset power, and then stops the operation of the cold machine system 300. In one aspect, the heat in the cold machine system 300 can be fully utilized, and energy waste can be avoided. In another aspect, the cold machine system 300 can be protected, and thermal stress of the compressor 322, the transfer heat exchanger and other structures caused by sudden stop can be avoided, so that the compressor 322, the transfer heat exchanger and other structures are prevented from being damaged, deformed and cracked, and the safety and reliability of the cold machine system 300 are ensured.

[0138] In some embodiments, the preset power is 25% of the rated power. When the power of the compressor 322 is reduced to below 25% of the rated power of the compressor 322, the cold machine system 300 can stop operating.

[0139] In this embodiment, the combustion system 100 includes the normal-temperature transfer tank 102 and the second fuel pump 142. The heat exchange system 200 is provided with the heat exchange liquid storage tank 203, the heat exchange liquid driving pump 211 and the heat exchange temperature sensor 214. The thermal engine system 400 includes the cooling structure 401 and the cooling liquid driving pump 413. The controller is electrically connected with the second fuel pump 142, the heat exchange liquid driving pump 211 and the cooling liquid driving pump 413.

[0140] The step S134 further includes a step S1342.

[0141] In the step S1342, when the power device is in the thermal engine working mode, the controller is electrically connected with the heat exchange liquid driving pump 211, the cooling liquid driving pump 413 and the heat exchange temperature sensor 214, and the controller can adjust the power of the heat exchange liquid driving pump 211 and the cooling liquid driving pump 413 according to the temperature information of the heat exchange agent obtained by the heat exchange temperature sensor 214.

[0142] When the power device is in the thermal engine working mode, the heat generated by each working power of the engine 106 is different, so that the heat absorbed by the cooling system is different. The controller can adjust the cooling effect of the cooling structure 401 in real time by adjusting the power of the cooling liquid driving pump 413 and the heat exchange liquid driving pump 211, so as to ensure the safe and stable operation of the engine 106.

[0143] In this embodiment, when the ship switches the fuel or restarts after a short stop of the engine 106, the temperature in the engine 106 still reaches the first preset standard. The control method further includes a step S140.

[0144] In the step S140, after the engine 106 is stopped for a short time, the controller controls the thermal engine system 400 and the heat exchange system 200 to start, and detects the temperature information of the cooling liquid by the engine temperature sensor 411. When the temperature of the cooling liquid reaches the first preset standard, the controller controls the power device to switch to the thermal engine working mode.

[0145] When the engine 106 is restarted after a short shutdown or switches fuel, the controller starts the heat engine system 400 and the heat exchange system 200, and determines whether the temperature of the coolant is greater than a first preset standard according to the temperature information of the coolant detected by the engine temperature sensor 411.

[0146] When the temperature of the coolant is greater than the first preset standard, the controller controls the power device to switch to the heat engine working mode, so as to make full use of the heat generated by the engine 106 to work, and improve the energy utilization efficiency. Moreover, the working efficiency of the power device can be effectively improved.

[0147] When the temperature of the coolant is less than the first preset standard, the controller controls the power device to switch to the hybrid working mode or the cold engine working mode.

[0148] Although the present application has been described with reference to several exemplary embodiments, it is understood that the words that have been used are words of description and illustration, rather than words of limitation. As the application can be embodied in many different forms without departing from the spirit or essential characteristics thereof, it is understood that the present embodiments are not limited to any particular details of the foregoing description, but are rather to be interpreted in keeping with the spirit and scope of the appended claims, thus falling within the purview of the claims or equivalents thereof.

Claims

1. A marine LNG power plant, characterized in that, The application relates to a natural gas engine system, comprising: a combustion system, which comprises a vaporizer and an engine; the vaporizer is used for vaporizing liquid natural gas into natural gas; the engine is connected with the vaporizer, and the engine is used for receiving the natural gas and burning to do work; a heat exchange system, which is connected with the vaporizer, and heat in the heat exchange agent in the heat exchange system can be transferred to the vaporizer to vaporize the liquid natural gas; a cold machine system, which is connected with the heat exchange system, and the heat exchange agent in the heat exchange system can be heated by the cold machine system; a hot machine system, which is connected with the heat exchange system, and the cooling liquid in the hot machine system can be heated by the heat exchange agent in the heat exchange system.

2. The power plant of claim 1, wherein, The heat exchange system comprises a first heat exchanger and a second heat exchanger which are connected in sequence, and the first heat exchanger is located upstream of the second heat exchanger; the first heat exchanger is connected with the cold machine system, so that the heat exchange agent can absorb the heat of the heat supply agent in the first heat exchanger; the second heat exchanger is connected with the vaporizer and located upstream of the vaporizer; the second heat exchanger is connected with the hot machine system, so that the heat exchange agent can absorb the heat in the cooling liquid in the second heat exchanger.

3. A power plant according to claim 1 or 2, characterised in that The cold machine system comprises a heating circuit and a transfer circuit; the heat supply agent comprises a first heat supply agent and a second heat supply agent; the first heat supply agent flows in the heating circuit; the heating circuit can evaporate and compress the first heat supply agent to form high-temperature steam; the second heat supply agent flows in the transfer circuit, and the transfer circuit is connected with the heating circuit and the heat exchange system; the second heat supply agent can absorb the heat in the high-temperature steam and transfer the heat to the heat exchange agent.

4. The power plant of claim 3, wherein The transfer circuit comprises at least one transfer heat exchanger; the heating circuit comprises an evaporator and at least one compressor which are connected in sequence; the evaporator can evaporate the first heat supply agent to form steam; the compressor can compress the steam to form high-temperature steam; the compressor is located upstream of the adjacent transfer heat exchanger, so that the high-temperature steam can be input into the transfer heat exchanger to exchange heat with the second heat supply agent.

5. The power plant of claim 4, wherein, The transfer circuit further comprises a transfer liquid storage tank and a transfer liquid pump; the transfer liquid storage tank is connected with the transfer heat exchanger, and the transfer liquid storage tank is used for containing the second heat supply agent; the transfer liquid pump is arranged between the transfer liquid storage tank and the transfer heat exchanger, so that the second heat supply agent in the transfer liquid storage tank can be pumped into the transfer heat exchanger.

6. The power plant of claim 5, wherein, The heat exchange system comprises a first heat exchanger and a second heat exchanger which are connected in sequence, and the first heat exchanger is located upstream of the second heat exchanger; the first heat exchanger is connected with the cold machine system, so that the heat exchange agent can absorb the heat of the heat supply agent in the first heat exchanger; The delivery loop further comprises a plurality of delivery temperature sensors, each of which is arranged upstream and downstream of the first heat exchanger, and is configured to obtain temperature information of the second heat supply agent.

7. The power plant of claim 2, wherein The heat engine system further comprises a cooling structure and an engine temperature sensor, the cooling structure is arranged on the engine and the cooling liquid flows through the cooling structure, the cooling structure is connected with the second heat exchanger to input the cooling liquid into the second heat exchanger, and the engine temperature sensor is arranged between the cooling structure and the second heat exchanger and is configured to detect temperature information of the cooling liquid output by the cooling structure.

8. The power plant of claim 2, wherein, The heat exchange system further comprises a heat exchange liquid storage tank and a heat exchange liquid pump, the heat exchange liquid storage tank is arranged between the second heat exchanger and the vaporizer and is configured to store the heat exchange agent, and the heat exchange liquid pump is arranged at an output end of the heat exchange liquid storage tank and is configured to output the heat exchange agent in the heat exchange liquid storage tank into the vaporizer.

9. The power plant of claim 1, wherein, The first control valve is arranged on the heat exchange system, the second control valve is arranged on the cold engine system, and the third control valve is arranged on the heat engine system. The power device further comprises a controller, which is electrically connected with the first control valve, the second control valve and the third control valve to control the on-off of the first control valve, the second control valve and the third control valve.

10. The power plant of claim 1, wherein, The combustion system further comprises a normal-temperature transfer tank, which is configured to accommodate the liquid natural gas and warm the liquid natural gas, and is connected with an input end of the vaporizer to input the stored liquid natural gas into the vaporizer for vaporization. In addition, the combustion system further comprises a pressure stabilizer and a gas-liquid separator, the pressure stabilizer is connected with an output end of the vaporizer to receive the natural gas vaporized and output by the vaporizer, and the gas-liquid separator is connected with an output end of the pressure stabilizer to separate residual liquid natural gas in the natural gas.

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