Ship LNG power device and control method thereof

Abstract

The invention provides a ship LNG power device and a control method thereof. 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 present invention relates to the technical field of ship power, and particularly relates to a ship LNG power device and a control method thereof. Background Art

[0002] LNG (Liquefied Natural Gas) ships use liquefied natural gas as the main fuel to drive the ship to sail. Compared with traditional fuel ships, LNG ships have the advantages of low carbon environmental protection, high efficiency, and economy.

[0003] When the liquefied natural gas in an LNG ship is in use, generally, an electric heating device is used to heat the liquefied natural gas so that the liquefied natural gas is heated up and vaporized to form natural gas. However, there is energy waste in the conversion between fuel, electricity, and heat, and moreover, the electric heating device is prone to failure, resulting in uncontrollable temperature, which increases the safety hazards of the power device. Summary of the Invention

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

[0005] To solve the above technical problems, the present application adopts the following technical solutions:

[0006] According to one aspect of the present application, the present application provides a ship LNG power device, which includes: a combustion system, a heat exchange system, a cold machine system, and a heat engine system; the combustion system includes a vaporizer and an engine; the vaporizer is used for vaporizing liquefied natural gas into natural gas; the engine is connected to the vaporizer, and the engine is used for receiving the natural gas and burning to do work; a heat exchange agent circulates in the heat exchange system, and the heat exchange system is connected to the vaporizer to be able to transfer the heat in the heat exchange agent to the vaporizer to vaporize the liquefied natural gas; a heat supply agent circulates inside the cold machine system, and the cold machine system can heat up the heat supply agent and can input the heat of the heat supply agent into the heat exchange system to heat the heat exchange agent; a coolant circulates in the heat engine system, and the coolant is used for absorbing the heat of the engine; the coolant can transfer the heat to the heat exchange system to heat the heat exchange agent.

[0007] In some embodiments, the heat exchange system includes a first heat exchanger and a second heat exchanger connected in communication, and the first heat exchanger is located upstream of the second heat exchanger; the first heat exchanger is connected to the cold machine system so that the heat exchange agent absorbs the heat of the heat supply agent through the first heat exchanger; the second heat exchanger is connected to the vaporizer and is located upstream of the vaporizer; the second heat exchanger is connected to the heat engine system so that the heat exchange agent absorbs the heat in the coolant through the second heat exchanger.

[0008] In some embodiments, the cold machine system includes a heating circuit and a transfer circuit; the heat supply agent includes a first heat supply agent and a second heat supply agent; the first heat supply agent circulates in the heating circuit; the heating circuit can evaporate and then compress the first heat supply agent to form high-temperature steam; the second heat supply agent circulates in the transfer circuit, and the transfer circuit is connected to the heating circuit and the heat exchange system, and the second heat supply agent can absorb the heat in the high-temperature steam and transfer the heat to the heat exchange agent.

[0009] In some embodiments, the transfer circuit includes at least one transfer heat exchanger; the heating circuit includes an evaporator and at least one compressor connected in sequence. The evaporator can evaporate the first heat supply agent to form steam, and the compressor can compress the steam to form high-temperature steam. The compressor is located upstream of the adjacent transfer heat exchanger to be able to input the high-temperature steam into the transfer heat exchanger for heat exchange with the second heat supply agent.

[0010] In some embodiments, the transfer circuit further includes a transfer liquid storage tank and a transfer liquid driving pump. The transfer liquid storage tank is connected to the transfer heat exchanger and is used to contain 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 includes 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 to obtain the temperature information of the second heat supply agent.

[0012] In some embodiments, the heat engine system further includes a cooling structure and an engine temperature sensor. The cooling structure is arranged on the engine, and the coolant circulates in the cooling structure; the cooling structure is connected to the second heat exchanger to input the coolant 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 to detect the temperature information of the refrigerant output by the cooling structure.

[0013] In some embodiments, the heat exchange system further includes 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 is used to store the heat exchange agent; the heat exchange liquid driving pump is arranged at the output end of the liquefaction liquid storage tank to output the heat exchange agent in the heat exchange liquid storage tank to the vaporizer.

[0014] In some embodiments, a first control valve is provided on the heat exchange system, a second control valve is provided on the chiller system, and a third control valve is provided on the heat engine system; the power device further includes a controller, and the controller is electrically connected to the first control valve, the second control valve, and the third control valve to be able to control the opening and closing of the first control valve, the second control valve, and the third control valve.

[0015] In some embodiments, the combustion system further includes a normal temperature transfer tank for accommodating the liquefied natural gas and heating the liquefied natural gas; the normal temperature transfer tank is connected to the input end of the vaporizer to be able to input the stored liquefied natural gas into the vaporizer for vaporization; and / or, the combustion system further includes a voltage stabilizer and a gas-liquid separator, the voltage stabilizer is connected to the output end of the vaporizer to receive the natural gas vaporized and output by the vaporizer; the gas-liquid separator is connected to the output end of the voltage stabilizer to separate the residual liquefied natural gas in the natural gas.

[0016] A control method for a ship LNG power device, the control method is used to control the ship LNG power device as described in any one of the above; the control method includes: the chiller system can heat the heat supply agent and heat the heat exchange agent through the heat supply agent; the coolant in the heat engine system can absorb the heat generated when the engine burns and does work, and transfer the heat to the heat exchange agent; after the heat exchange agent in the heat exchange system is heated, the heat exchange agent can exchange heat with the liquefied natural gas through the vaporizer, so that the liquefied natural gas is heated and vaporized to form natural gas and is transported into the engine for combustion.

[0017] In some embodiments, an engine temperature sensor is provided on the heat engine system, and the engine temperature sensor is used to detect the temperature information of the coolant flowing through the engine; the power device further includes a controller, and the controller is electrically connected to the engine temperature sensor to obtain the detected temperature information of the coolant, and the controller can be electrically connected to the chiller system, the heat engine system, the heat exchange system, and the combustion system; the chiller system, the heat exchange system, and the combustion system can be started and operated to form a chiller working mode; the chiller system, the heat engine system, the heat exchange system, and the combustion system can be started and operated to form a hybrid working mode; the heat engine system, the heat exchange system, and the combustion system can be started and operated to form a heat engine working mode; the controller can control the switching of the chiller working mode, the hybrid working mode, and the heat engine working mode according to the temperature information of the engine temperature sensor.

[0018] In some embodiments, a first preset standard is preset in the controller; when the engine temperature sensor detects that the temperature of the coolant reaches the first preset standard, the controller controls the compressor to gradually reduce its power until the power of the compressor is reduced below the preset power, and then the cold engine system stops operating and the power device switches to the hot engine working mode.

[0019] As can be seen from the above technical solutions, the present application has at least the following advantages and positive effects:

[0020] In the present application, when the ship starts, the operation of the heat exchange system, the cold engine system and the hot engine system can be controlled to ensure that the 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 natural gas, avoiding the uncontrollable temperature caused by directly heating the liquefied natural gas with an electric heater in the related art and reducing the potential safety hazards of the power device. Moreover, the power device recovers the heat generated by the engine during combustion work through the hot engine system, improving the energy utilization efficiency of the power device and avoiding waste of energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of the power device of the present invention.

[0022] Figure 2 is a schematic flowchart of the control method of the power device of the present invention.

[0023] Figure 3 is a schematic flowchart of step S130 of the control method of the present invention.

[0024] Figure 4 is a schematic flowchart of steps S131 to S134 of the control method of the present invention.

[0025] Figure 5 is a schematic flowchart of steps S1341 and S1342 of the control method of the present invention.

[0026] Figure 6 is a schematic flowchart of step S140 of the control method of the present invention.

[0027] The description of the reference numerals in the drawings is as follows: 100, combustion system; 101, storage tank; 102, normal-temperature transfer tank; 103, vaporizer; 104, voltage 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 liquid storage tank; 211, heat exchange liquid displacement pump; 212, first control valve; 213, first pressure relief valve; 214, heat exchange temperature sensor; 300, chiller system; 310, transfer loop; 311, third heat exchanger; 312, fourth heat exchanger; 313, transfer liquid storage tank; 314, transfer liquid displacement pump; 315, second control valve; 316, transfer temperature sensor; 317, second pressure relief valve; 320, heating circuit; 321, evaporator; 322, compressor; 323, throttle valve; 400, heat engine system; 401, cooling structure; 411, engine temperature sensor; 412, third control valve; 413, cooling liquid displacement pump; 414, third pressure relief valve. Detailed implementation manners

[0028] Typical implementation manners reflecting the features and advantages of the present application will be described in detail in the following description. It should be understood that the present application can have various changes in different implementation manners, all of which do not depart from the scope of the present application, and the descriptions and illustrations therein are essentially for illustrative purposes rather than for limiting the present application.

[0029] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. 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, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the said features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0030] LNG (Liquefied Natural Gas) ships use liquefied natural gas as the main fuel to drive the ship to sail.

[0031] In the related art, LNG ships directly heat liquid natural gas into natural gas through electric heaters, which easily leads to unstable heating temperature, and the electric heating equipment is prone to failure, resulting in uncontrollable temperature, increasing the safety hazards of the power device.

[0032] Refer to Figure 1 , this application provides a marine LNG power device, which includes: a combustion system 100, a heat exchange system 200, a cold machine system 300, and a heat engine system 400. The combustion system 100 includes a vaporizer 103 and an engine 106. The vaporizer 103 is used to vaporize liquid natural gas into natural gas. The engine 106 is connected to the vaporizer 103, and the engine 106 is used to receive natural gas and burn to do work. A heat transfer medium flows in the heat exchange system 200, and the heat exchange system 200 is connected to the vaporizer 103 to be able to transfer the heat in the heat transfer medium to the vaporizer 103 to vaporize the liquid natural gas. A heat supply medium flows inside the cold machine system 300. The cold machine system 300 can heat up the heat supply medium and can input the heat of the heat supply medium into the heat exchange system 200 to heat the heat transfer medium. A coolant flows in the heat engine system 400, and the coolant is used to absorb the heat of the engine 106. The coolant can transfer the heat to the heat exchange system 200 to heat the heat transfer medium.

[0033] When the marine LNG power device (hereinafter referred to as the power device for short) starts, it can control the operation of the heat exchange system 200, the cold machine system 300, and the heat engine system 400, so that the heat exchange system 200 can absorb the heat in the cold machine system 300 and the heat engine system 400. After the heat transfer medium in the heat exchange system 200 absorbs heat, it can transfer the heat to the vaporizer 103 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 with an electric heater in the related art, and effectively reducing the safety hazards of the power device.

[0034] Moreover, the power device can recover the heat generated by the engine 106 during combustion and work through the heat engine system 400, improve the energy utilization efficiency of the power device, and avoid waste of energy.

[0035] Refer to Figure 1 , in this embodiment, the power device includes a vaporizer 103 and an engine 106. The vaporizer 103 can vaporize liquid natural gas into natural gas. The engine 106 is located downstream of the vaporizer 103 to be able to receive the natural gas output by the vaporizer 103 and burn to do work, thereby driving the ship to move.

[0036] In some embodiments, the vaporizer 103 can be a shell-and-tube vaporizer 103 or a plate vaporizer 103.

[0037] In some other embodiments, the vaporizer 103 may include a first vaporization inlet end, a second vaporization inlet end, a first vaporization outlet end, and a second vaporization outlet end. The first vaporization inlet end may be in communication with a gas source of liquefied natural gas so as to facilitate the input of liquefied natural gas into the vaporizer 103. The first vaporization outlet end may be in communication with the engine 106 for outputting natural gas into the engine 106. The second vaporization input end may be connected to the heat exchange system 200 for inputting a heat exchange agent into the vaporizer 103. The second vaporization output end is used for outputting the heat exchange agent in the vaporizer 103 after heat exchange with the liquefied natural gas.

[0038] Referring to Figure 1 , in the present embodiment, the combustion system 100 may further include a storage tank 101 for storing liquefied natural gas, and the storage tank 101 is the gas source of liquefied natural gas.

[0039] In some embodiments, the storage tank 101 may be an external structure, and the vaporizer 103 is detachably connected to the storage tank 101.

[0040] Referring to Figure 1 , in the present embodiment, the combustion system 100 may further include a normal temperature transfer tank 102. The normal temperature transfer tank 102 is in communication with the storage tank 101, and the normal temperature transfer tank 102 is used for accommodating the liquefied natural gas output from the storage tank 101. The normal temperature transfer tank 102 can perform heat exchange with the external environment to raise the temperature of the accommodated liquefied natural gas, so as to reduce the heat required for subsequent vaporization of the vaporizer 103 and improve the vaporization efficiency of the liquefied natural gas. The normal temperature transfer tank 102 is in communication with the input end of the vaporizer 103 to be able to input the stored liquefied natural gas into the vaporizer 103 for vaporization.

[0041] Moreover, the cold energy released by the normal temperature transfer tank 102 can be used for refrigeration in the cold storage room and the living and working space to improve the energy utilization efficiency of the power device.

[0042] Referring to Figure 1 , in the present embodiment, the combustion system 100 may further include a voltage stabilizer 104 and a gas-liquid separator 105. The voltage stabilizer 104 is connected to the output end of the vaporizer 103 for receiving the natural gas vaporized and output by the vaporizer 103. The voltage stabilizer 104 can stabilize the pressure of the natural gas and ensure a stable flow rate. The gas-liquid separator 105 is connected to the output end of the voltage stabilizer 104 for separating the residual liquefied natural gas in the natural gas. The gas-liquid separator 105 can transport the separated natural gas into the engine 106 to prevent liquid hydrocarbons or moisture from entering the engine 106, making the combustion work of the engine 106 more stable and prolonging the service life of the engine 106.

[0043] In some embodiments, the gas-liquid separator 105 may be connected to the storage tank 101, the normal-temperature transfer tank 102, or the vaporizer 103 to return the separated liquid natural gas to the storage tank 101, the normal-temperature transfer tank 102, or the vaporizer 103, so as to realize the reuse of the liquid natural gas and improve the resource utilization efficiency of the power device.

[0044] In other embodiments, the gas-liquid separator 105 may be connected to other external devices to transport the separated liquid natural gas into external gaseous devices for utilization.

[0045] Referring to Figure 1 , in this embodiment, the fuel system further includes 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 voltage stabilizer 104, so as to facilitate the control of the operation and stop of each functional device.

[0046] The plurality of fuel valves include 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 voltage stabilizer 104. The settings of the first fuel valve 121, the second fuel valve 122, and the third fuel valve 123 can respectively cut off and connect the storage tank 101, the normal-temperature transfer tank 102, the vaporizer 103, and the voltage stabilizer 104, thus facilitating the replacement and maintenance of individual functional devices.

[0047] In some embodiments, the fuel valve may be an electric valve.

[0048] In some embodiments, the gas-liquid separator 105 may further include a plurality of stop valves, which are used to adjust the flow rate of the fluid transported to the downstream functional device. Moreover, the stop valve can also prevent the reverse flow of liquid and gas flow, playing a role in safety protection.

[0049] The plurality of stop valves include 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 adjust the flow rate of the liquid natural gas input from the normal-temperature transfer tank 102 into the vaporizer 103 in real time. The second stop valve 132 can adjust the flow rate of the natural gas output from the vaporizer 103 to the voltage stabilizer 104.

[0050] In some embodiments, the stop valve may be an electric valve.

[0051] Referring to Figure 1 , in this embodiment, the heat exchange system 200 further includes a plurality of fuel pumps, which are respectively arranged downstream of the functional device, so as to pump the liquid in the upstream functional device into the downstream functional device.

[0052] A 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 the storage tank 101 and is in communication with the storage tank 101 to pump the liquefied natural gas in the storage tank 101 into the normal temperature transfer tank 102. The second fuel pump 142 is disposed downstream of the normal temperature transfer tank 102 and is in communication with the normal temperature transfer tank 102 to pump the liquefied natural gas in the normal temperature transfer tank 102 into the vaporizer 103.

[0053] Refer to Figure 1 , in this embodiment, the power plant further includes a heat exchange system 200. The heat exchange system 200 is used to absorb the heat in the chiller system 300 and the heat engine system 400, and can transfer the heat to the combustion system 100 to vaporize the liquefied natural gas into natural gas.

[0054] The heat exchange system 200 includes a first heat exchanger 201 and a second heat exchanger 202 which are 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 chiller system 300 so that the heat exchange medium absorbs the heat of the heat supply medium 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 engine system 400 so that the heat exchange medium absorbs the heat in the coolant through the second heat exchanger 202. The heat exchange medium in the second heat exchanger 202 is output into the vaporizer 103 so that the heat exchange medium exchanges heat with the liquefied natural gas through the vaporizer 103.

[0055] In some embodiments, the first heat exchanger 201, the second heat exchanger 202 and the vaporizer 103 are sequentially connected end to end in series so that the first heat exchanger 201, the second heat exchanger 202 and the vaporizer 103 form a closed loop, thereby facilitating the circulation of the heat exchange medium in the closed loop, enabling the heat exchange medium to be recycled, improving the utilization efficiency of the heat exchange medium, and reducing the use cost.

[0056] In some embodiments, the first heat exchanger 201 and the second heat exchanger 202 can be shell-and-tube heat exchangers or plate heat exchangers.

[0057] In other embodiments, the first heat exchanger 201 may 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 vapor output end of the vaporizer 103 to input the heat exchange medium after heat exchange 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 medium 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 chiller system 300 to input the heat supply medium into the first heat exchanger 201, thereby facilitating the heat exchange between the heat exchange medium and the heat supply medium.

[0058] In some other embodiments, the relevant structure of the second heat exchanger 202 may refer to the structure of the first heat exchanger 201, so that the second heat exchanger 202 can receive the heat transfer agent in the first heat exchanger 201, and the heat transfer agent in the second heat exchanger 202 is output to the vaporizer 103 after exchanging heat with the heat engine system 400.

[0059] 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 communicated 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 communicated 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 coolant into the second heat exchanger 202, so as to facilitate the heat exchange between the heat transfer agent and the coolant.

[0060] Refer to Figure 1 , in this embodiment, a first control valve 212 is provided on the heat exchange system 200. The first control valve 212 is arranged downstream of the second heat exchanger 202. The first control valve 212 can control 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.

[0061] In some embodiments, the first control valve 212 can be an electric valve.

[0062] Refer to Figure 1 , in this 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 the heat exchange liquid storage tank 203 is used for storing the heat transfer agent output by the second heat exchanger 202. The heat exchange liquid driving pump 211 is arranged at the output end of the liquefied liquid storage tank for outputting the heat transfer agent in the heat exchange liquid storage tank 203 into the vaporizer 103.

[0063] The heat exchange liquid storage tank 203 is used for accommodating the heat transfer agent output by the second heat exchanger 202, and the heat exchange liquid driving pump 211 is used for outputting the heat transfer agent in the heat exchange liquid storage tank 203 into the vaporizer 103. On the one hand, it can ensure the stable pressure of the heat transfer agent output in the heat exchange system 200 and avoid the problem of low vaporization efficiency of liquefied natural gas caused by too little heat transfer agent input into the vaporizer 103; on the other hand, it can also make the heat transfer agent mix in the heat exchange liquid storage tank 203, ensure the uniform temperature of the output heat transfer agent, facilitate the monitoring and regulation of the heat exchange system 200, and ensure the vaporization efficiency and stability of the vaporizer 103.

[0064] Refer to Figure 1, in this embodiment, the heat exchange system 200 further includes a first pressure relief valve 213. The first pressure relief valve 213 is disposed between the heat exchange liquid delivery pump 211 and the vaporizer 103 for discharging a part of the heat exchange agent output by the heat exchange liquid delivery pump 211, preventing the pressure of the heat exchange agent input into the vaporizer 103 from being too high and damaging the vaporizer 103, and avoiding the heat exchange agent input into the vaporizer 103 from flowing too fast, which may lead to low heat exchange efficiency and poor heat transfer uniformity.

[0065] Refer to Figure 1 , in this embodiment, the heat exchange system 200 further includes a heat exchange temperature sensor 214. The heat exchange temperature sensor 214 is disposed downstream of the vaporizer 103 for detecting the temperature of the heat exchange agent output by the vaporizer 103 and obtaining heat exchange agent temperature information, so as to facilitate the staff to control the start and stop of the combustion system 100, the heat exchange system 200, the chiller system 300 and the heat engine system 400, and improve the working efficiency of the power device.

[0066] In some embodiments, the heat exchange temperature sensor 214 may be disposed between the vaporizer 103 and the first heat exchanger 201 to facilitate obtaining the temperature of the heat exchange agent after passing through the vaporizer 103, so as to facilitate the staff to judge the vaporization effect of the vaporizer 103 according to the temperature of the heat exchange agent.

[0067] Refer to Figure 1 , in this embodiment, the power device may further include a chiller system 300. The chiller system 300 is connected to 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 chiller system 300 can be started independently according to the operating state of the engine 106 or the needs of the staff, and can also be started in combination with the heat engine system 400 to ensure the stable, safe and reliable operation of the power device under various working conditions.

[0068] The chiller system 300 includes a heating circuit 320 and a transfer circuit 310. The heat supply agent includes a first heat supply agent and a second heat supply agent. The first heat supply agent circulates 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 circulates in the transfer circuit 310. The transfer circuit 310 is connected to the heating circuit 320 and the heat exchange system 200. The second heat supply agent can absorb the 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 ensure the uniform temperature of the heat exchange agent after being heated.

[0069] In some embodiments, the transfer circuit 310 includes at least one transfer heat exchanger. The relevant structure of the transfer heat exchanger can be set with reference to the structure of the first heat exchanger 201.

[0070] A second heat supply agent flows through the transfer heat exchanger. The transfer heat exchanger may include a first transfer input end, a first transfer output end, a second transfer input end, and a second transfer output end. The first transfer input end may be connected to the second heat exchange output end of the first heat exchanger 201, and the first transfer output end may be connected to the second heat exchange input end of the first heat exchanger 201, so that a closed loop is formed between the transfer heat exchanger and the first heat exchanger 201, thereby facilitating the circulation of the second heat supply agent in the transfer heat exchanger and the first heat exchanger 201 and improving the utilization efficiency of the second heat supply agent. The second transfer input end and the second transfer output end may be connected to the heating circuit 320, so that the first heat supply agent can flow into the transfer heat exchanger to exchange heat with the second heat supply agent, thereby increasing the temperature of the second heat supply agent.

[0071] In some embodiments, the transfer loop 310 may include two transfer heat exchangers. The two transfer heat exchangers are the third heat exchanger 311 and the fourth heat exchanger 312 respectively. The third heat exchanger 311, the fourth heat exchanger 312, and the first heat exchanger 201 are connected end to end in sequence, 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, realizing the multi-stage heating of the second heat supply agent, improving the heating effect of the second heat supply agent, and ensuring the utilization efficiency of the second heat supply agent.

[0072] The first transfer output end of the third heat exchanger 311 is communicated with the first transfer input end of the fourth heat exchanger 312, the first transfer output end of the fourth heat exchanger 312 is communicated 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 communicated with the first transfer input end of the third heat exchanger 311, thus forming a closed loop.

[0073] In other embodiments, the transfer loop 310 may include three or four transfer heat exchangers connected in series in sequence to realize the multi-stage heating of the second heat supply agent.

[0074] Refer to Figure 1 , in this embodiment, the transfer loop 310 further includes a transfer liquid storage tank 313 and a transfer liquid driving pump 314. The transfer liquid storage tank 313 is communicated with the transfer heat exchanger, and the transfer liquid storage tank 313 is used to contain the second heat supply agent. The transfer liquid driving pump 314 is arranged between the transfer liquid storage tank 313 and the transfer heat exchanger to pump the second heat supply agent in the transfer liquid storage tank 313 into the transfer heat exchanger, thereby being able to control the amount of the second heat supply agent input into the transfer heat exchanger and ensuring the safety of the transfer heat exchanger.

[0075] In some embodiments, the transfer liquid storage tank 313 is disposed between the first heat exchanger 201 and the third heat exchanger 311. The input end of the transfer liquid storage tank 313 is communicated with the second heat exchange output end of the first heat exchanger 201, and the output end of the transfer liquid storage tank 313 is communicated with the first transfer input end of the third heat exchanger 311. The transfer liquid storage tank 313 is used to accommodate and store the second heating agent output by the first heat exchanger 201, so as to uniformly supply the second heating agent to the transfer heat exchanger through the transfer liquid pump 314, ensuring the stable and reliable operation of the transfer loop 310.

[0076] Referring to Figure 1 , in this embodiment, the transfer loop 310 further includes a plurality of transfer temperature sensors 316. The plurality of transfer temperature sensors 316 are respectively disposed upstream and downstream of the first heat exchanger 201. The transfer temperature sensors 316 are used to detect and obtain the temperature information of the second heating agent, so as to facilitate the staff to adjust the working state of the heating loop 320 according to the temperature information of the second heating agent.

[0077] In some embodiments, the transfer loop 310 includes two transfer temperature sensors 316. One of the transfer temperature sensors 316 is disposed between the first heat exchanger 201 and the transfer liquid storage tank 313 to obtain the temperature information of the second heating agent output by the first heat exchanger 201; the other transfer temperature sensor 316 is disposed between the fourth heat exchanger 312 and the first heat exchanger 201 to obtain the temperature information of the second heating agent input from the fourth heat exchanger 312 to the first heat exchanger 201. The staff can adjust the working state of the chiller system 300 in real time according to the temperature information of the two transfer temperature sensors 316, so as to adjust the heat exchange efficiency of the first heat exchanger 201.

[0078] Referring to Figure 1 , in this embodiment, a second control valve 315 is provided on the chiller system 300 to control the start and stop of the chiller system 300. The second control valve 315 can be disposed on the transfer loop 310 to control the on-off of the transfer loop 310, thereby realizing the start and stop of the chiller system 300.

[0079] In some embodiments, the second control valve 315 is disposed between the first heat exchanger 201 and the transfer liquid storage tank 313. In some other embodiments, the second control valve 315 can be an electric valve.

[0080] Referring to Figure 1 , in this embodiment, the transfer loop 310 further includes a second pressure relief valve 317. The second pressure relief valve 317 is disposed between the first heat exchanger 201 and the transfer liquid storage tank 313 to discharge the second heating agent in the transfer loop 310, thereby ensuring the stable and reliable operation of the transfer loop 310.

[0081] In some embodiments, the second pressure relief valve 317 is disposed between the first heat exchanger 201 and the second control valve 315. When the second control valve 315 is closed, the second pressure relief valve 317 can discharge part of the second heat carrier, avoiding the impact and damage of the second heat carrier output by the fourth heat exchanger 312 on the first heat exchanger 201, and ensuring the safety and stability of the transfer loop 310.

[0082] Referring to Figure 1 , in this embodiment, the heating loop 320 includes an evaporator 321 and at least one compressor 322 connected in sequence. The evaporator 321 can evaporate the first heat carrier 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 to be able to input the high-temperature steam into the transfer heat exchanger to exchange heat with the second heat carrier. The heating loop 320 heats through the evaporator 321 and the compressor 322, avoiding the potential safety hazards easily generated by the electric heater, effectively ensuring the safety and reliability of the heating loop 320, and enabling the heating loop 320 to generate heat stably and uniformly.

[0083] In some embodiments, the heating loop 320 includes an evaporator 321 and a compressor 322. The transfer loop 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 carrier, thereby heating the second heat carrier.

[0084] In some embodiments, the heating loop 320 includes an evaporator 321 and two compressors 322. The transfer loop 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 to input high-temperature steam into the third heat exchanger 311 to exchange heat with the second heat carrier. The second transfer output end of the third heat exchanger 311 is connected to the input end of the other compressor 322, and the other compressor 322 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 to input the high-temperature steam formed by re-compression into the fourth heat exchanger 312 to exchange heat with the second heat carrier, thereby performing multi-stage heating on the second heat carrier, increasing the temperature of the second heat carrier, increasing the temperature of the heat carrier in the heat exchange system 200, and increasing the vaporization efficiency of the vaporizer 103.

[0085] 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. The evaporator 321, the two compressors 322, and the third heat exchanger 311 are connected in series in sequence. The evaporator 321 and the two compressors 322 perform multistage compression on the steam to form high-temperature steam, thereby increasing the temperature of the high-temperature steam and improving the heat exchange efficiency of the third heat exchanger 311.

[0086] Refer to Figure 1 , in this embodiment, the evaporator 321, the compressor 322, and the transfer heat exchanger are connected end to end in sequence to form a closed loop, and the first heating agent circulates in the closed loop, thereby effectively reducing the heating cost of the heating circuit 320.

[0087] Refer to Figure 1 , in this embodiment, the heating circuit 320 further includes a throttle valve 323. The throttle valve 323 is disposed upstream of the evaporator 321 to control the flow rate input into the evaporator 321 and control the evaporation efficiency of the evaporator 321. Moreover, the throttle valve 323 can prevent the first heating agent from impacting the evaporator 321 and ensure the safety and stability of the evaporator 321.

[0088] In some embodiments, the throttle valve 323 can be an electric throttle valve 323 to adjust the flow rate of the first heating agent flowing through according to requirements.

[0089] In some embodiments, the throttle valve 323 is disposed 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 heating agent input from the fourth heat exchanger 312 into the evaporator 321, avoid liquid impact on the evaporator 321, and ensure the safety and stability of the evaporator 321.

[0090] Refer to Figure 1 , in this embodiment, the heat engine system 400 further includes a cooling structure 401 and an engine temperature sensor 411. The cooling structure 401 is disposed on the engine 106, and a coolant flows through the cooling structure 401 to absorb the heat generated when the engine 106 operates. The cooling structure 401 is connected to the second heat exchanger 202 to input the coolant into the second heat exchanger 202. The engine temperature sensor 411 is disposed 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 refrigerant output by the cooling structure 401.

[0091] The power device can control the start and stop of the cold machine 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.

[0092] 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. The refrigerant flowing in the cooling structure 401 absorbs the heat of the engine 106 and then heats the heat transfer agent through the second heat exchanger 202, so that the heat in the engine 106 vaporizes the liquefied natural gas through the heat exchange system 200. At this time, the power device is in the heat engine working mode, the cold machine system 300 stops, and the heat engine system 400, the heat exchange system 200 and the combustion system 100 are started to make full use of the waste heat of the engine 106 and reduce the use cost of the power device. Moreover, it can reduce the start-up time of the power device and improve the user experience.

[0093] The temperature of the second preset standard is lower than the temperature 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, etc.

[0094] 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 stops, and the cold machine system 300 and the heat exchange system 200 are started to vaporize the liquefied natural gas. At this time, the power device is in the cold machine working mode to ensure the safe and stable operation of the power device.

[0095] 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 absorbed by the cooling structure 401 from the engine 106 is not sufficient to fully vaporize the liquefied natural gas. At this time, the power device is in the hybrid working mode, and the heat engine system 400, the cold machine system 300 and the heat exchange system 200 are all started to increase the temperature of the heat transfer agent and fully vaporize the liquefied natural gas, thereby reducing the use cost of the power device.

[0096] Refer to Figure 1 In this embodiment, a third control valve 412 is provided on the heat engine system 400. The third control valve 412 is used to control the start and stop of the heat engine system 400.

[0097] In some embodiments, the third control valve 412 is provided at the output end of the cooling structure 401 to control the output of the coolant in the cooling structure 401.

[0098] In some embodiments, the third control valve 412 is an electric valve.

[0099] 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 and does work, the heat generated by the fuel combustion is transferred slowly, so that the overall temperature of the engine 106 rises slowly.

[0100] When the overall temperature of the engine 106 is relatively low, the low-temperature environment will also affect the combustion effect of the fuel, resulting in incomplete combustion. The power unit can disconnect the heat engine system 400 through the third control valve 412 to prevent the coolant from absorbing the heat of the engine 106, so that the engine 106 can start stably and reliably, and improve the combustion efficiency of the fuel.

[0101] Refer to Figure 1 , in this embodiment, the heat engine system 400 further includes 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 communicated with the output end of the cooling structure 401 and the second heat exchange input end of the second heat exchanger 202, so as to be able to pump the coolant in the cooling structure 401 into the second heat exchanger 202, so that the coolant exchanges heat with the heat transfer agent. The cooling liquid pump 413 can adjust the pumping speed of the coolant, so as to adjust the heat exchange efficiency between the coolant and the heat transfer agent.

[0102] Refer to Figure 1 , in this embodiment, the heat engine system 400 further includes a third pressure relief valve 414. The third pressure relief valve 414 is arranged at the input end of the cooling structure 401 to be able to discharge part of the coolant, prevent the coolant 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.

[0103] Refer to Figure 1 , in this embodiment, the power unit further includes a controller (not shown in the figure). The controller can be electrically connected to the heat exchange temperature sensor 214, the transfer temperature sensor 316 and the engine temperature sensor 411 to be able to obtain the temperature information of the heat transfer agent, the second heat supply agent and the coolant.

[0104] The controller is electrically connected to the first control valve 212, the second control valve 315 and the third control valve 412 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, so as to be able to control the start and stop of the heat exchange system 200, the cold engine system 300 and the heat engine system 400.

[0105] In some embodiments, the controller can also be electrically connected to the voltage stabilizer 104, the gas-liquid separator 105, the first fuel valve 121, the second fuel valve 122, the third fuel valve 123, the first stop valve 131, the second stop valve 132, the first fuel pump 141 and the second fuel pump 142 to control the operation of the combustion system 100 and adjust the amount of natural gas input into the engine 106.

[0106] In some embodiments, the controller can also be electrically connected to the heat exchange liquid pump 211 to be able to control the flow efficiency of the heat transfer agent in the heat exchange system 200, so as to control the vaporization efficiency of the liquefied natural gas.

[0107] In some embodiments, the controller is further capable of being electrically connected to the evaporator 321, the compressor 322, and the throttle valve 323, so as to be able to control the heating efficiency of the heating circuit 320.

[0108] In some embodiments, the controller is further capable of being electrically connected to the cooling liquid pump 413, so as to be able to adjust the flow rate of the cooling liquid pumped out by the cooling liquid pump 413, thereby adjusting the cooling efficiency of the engine 106 and the heat exchange efficiency between the second heat exchanger 202 and the heat exchange agent.

[0109] The above embodiments are only illustrative examples of the structures. The structures in each embodiment are not fixedly combined structures. Without structural conflicts, the structures in multiple embodiments can be arbitrarily combined and used.

[0110] Referring to Figure 1 , the present application provides a marine LNG power device. When the power device is started, the temperature information of the cooling liquid in the heat engine system 400 is first detected by the engine temperature sensor 411, so as to be able to respectively control the operations of the heat exchange system 200, the cold machine system 300, and the heat engine system 400, so that the power device can flexibly switch between the cold machine working mode, the heat engine working mode, and the hybrid mode, thereby fully improving the energy utilization efficiency of the power device.

[0111] Moreover, when the power device is in the cold machine working mode, the heat engine working mode, or the hybrid working mode, by utilizing the waste heat of the engine 106 and technologies such as steam recompression, the heat exchange agent in the heat exchange system 200 is continuously and stably heated to heat the liquefied natural gas, so that the liquefied natural gas is safely and reliably vaporized to form natural gas, avoiding the problem of uncontrollable temperature caused by directly heating the liquefied natural gas with an electric heater in the related art and reducing the potential safety hazards of the power device.

[0112] Figure 2 is a schematic flow chart of the control method of the power device of the present invention.

[0113] Referring to FIGS. 1 and Figure 2 , the present application further provides a control method for a marine LNG power device. The control method is used to control any one of the above marine LNG power devices. The control method includes:

[0114] Step S110, the cold machine system 300 can heat up the heat supply agent and heat the heat exchange agent through the heat supply agent.

[0115] Step S120, the cooling liquid in the heat engine system 400 can absorb the heat generated when the engine 106 burns and does work, and transfer the heat into the heat exchange agent.

[0116] In step S200, after the heat transfer agent in the heat exchange system 200 is heated, the heat transfer agent can exchange heat with the liquefied natural gas through the vaporizer 103, so that the liquefied natural gas is heated and vaporized to form natural gas and is transported to the engine 106 for combustion.

[0117] When the ship starts, the cold engine system 300 and / or the heat engine system 400 starts, and the heat exchange system 200 starts. The heat transfer agent can receive the heat in the cold engine system 300 and the heat engine system 400, and can transfer the heat to the vaporizer 103 for heat exchange with the liquefied natural gas, so as to ensure that the heat in the heat transfer agent continuously and stably heats the liquefied natural gas, thereby ensuring that the liquefied natural gas is safely and reliably vaporized to form natural gas, and enabling the natural gas to be stably and safely input into the engine 106 for combustion work.

[0118] Moreover, the power device recovers the heat generated by the engine 106 during combustion work through the heat engine system 400, improving the energy utilization efficiency of the power device and avoiding waste of energy.

[0119] Figure 3 It is a schematic flow diagram of step S130 of the control method of the present invention.

[0120] Refer to Figures 2 to 3 In this embodiment, an engine temperature sensor 411 is provided on the heat engine system 400. The engine temperature sensor 411 is used to detect the temperature information of the coolant flowing through the engine 106. The power device further includes a controller, and the controller is electrically connected to the engine temperature sensor 411 to obtain the detected temperature information of the coolant. The controller can be electrically connected to the cold engine system 300, the heat engine system 400, the heat exchange system 200 and the combustion system 100.

[0121] The control method further includes: step S130.

[0122] In step S130, the cold engine system 300, the heat exchange system 200 and the combustion system 100 can be started and operated to form a cold engine working mode; the cold engine system 300, the heat engine system 400, the heat exchange system 200 and the combustion system 100 can be started and operated to form a hybrid working mode; the heat engine system 400, the heat exchange system 200 and the combustion system 100 can be started and operated to form a heat engine working mode; the controller can control the switching of the cold engine working mode, the hybrid working mode and the heat engine working mode according to the temperature information of the engine temperature sensor 411.

[0123] When the controller controls the power device to switch between the cold engine working mode, the heat engine working mode and the hybrid working mode according to the temperature information obtained by the engine temperature sensor 411, it can effectively and fully utilize the waste heat of the engine 106, improve the energy utilization efficiency of the power device, and reduce the operating cost of the ship.

[0124] Figure 4 It is a schematic flowchart of steps S131 to S134 of the control method of the present invention.

[0125] Refer to Figures 2 to 4 , in this embodiment, when the engine 106 of the ship has not been used for a long time, the temperature of the ship engine 106 gradually drops to normal temperature. At this time, when the engine 106 is to be used, it needs to first enter the cold engine working mode to vaporize the liquefied natural gas to provide fuel for the engine 106; then switch from the cold engine working mode to the hybrid working mode; and finally switch to the hot engine working mode.

[0126] The controller presets a first preset standard and a second preset standard.

[0127] Step S130 further includes step S131.

[0128] Step S131, when the power device is started, the controller controls the start of the hot engine system 400 and the heat exchange system 200; the controller detects the temperature information of the coolant through the engine temperature sensor 411; when the temperature of the coolant does not reach the second preset standard, the power device switches to the cold engine working mode.

[0129] When the power device is started, first, the controller controls the start of the hot engine system 400 and the heat exchange system 200, so that the coolant flows in the hot engine system 400 and exchanges heat with the heat exchange agent in the heat exchange system 200.

[0130] The controller can detect the temperature information of the coolant through the engine temperature sensor 411; when the temperature of the coolant tends to be stable and the temperature of the coolant is lower than the second preset standard, the controller controls the power device to switch to the cold engine working mode.

[0131] When the power device is in the cold engine working mode, on the one hand, it can avoid the coolant absorbing the heat when the engine 106 is started and affecting the starting efficiency of the engine 106, so that the fuel burns fully in the engine 106; on the other hand, it can fully vaporize the liquefied natural gas and improve the resource utilization efficiency.

[0132] In some embodiments, in the present embodiment, the chiller system 300 includes a heating circuit 320 and a transfer circuit 310. The heating agent includes a first heating agent flowing in the heating circuit 320 and a second heating 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 obtaining the temperature information of the second heating agent before and after heat exchange in the first heat exchanger 201. The controller is electrically connected to the transfer temperature sensor 316 to obtain the temperature difference information of the second heating agent based on the temperature information of the second heating agent before and after heat exchange in the first heat exchanger 201.

[0133] Referring to Figures 2 to 4 , step S130 further includes S132.

[0134] Step S132, the controller can obtain the temperature difference information of the second heating agent before and after heat exchange in the first heat exchanger 201 through the transfer temperature sensor 316, and the controller can dynamically adjust the power of the compressor 322 through the temperature difference information to adjust the temperatures of the first heating agent and the second heating agent.

[0135] 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 transfer temperature sensor 316, it can obtain the temperature information of the second heat exchange agent before passing through the first heat exchanger 201 and the temperature information after passing through the first heat exchanger 201, and can also obtain the temperature difference information of the second heating agent when passing through the first heat exchanger 201 by combining the two temperature information.

[0136] After the controller obtains the temperature difference information of the second heating agent, it can dynamically control the power of the compressor 322 to adjust the temperature of the first heating agent. The change in the temperature of the first heating agent will cause the temperature of the second heating agent to change. The change in the temperature of the second heating 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 liquefied natural gas through the vaporizer 103 to ensure the vaporization efficiency of the liquefied natural gas, thereby adjusting the combustion efficiency of the combustion system 100.

[0137] Moreover, the heat exchange agent is heated by the recompression technology of steam, so as to transfer the heat to the vaporizer 103 to vaporize the liquefied natural gas, effectively avoiding the problems of uncontrollable temperature and easy occurrence of safety hazards caused by directly heating the liquefied natural gas with an electric heater in the related art.

[0138] Referring to Figures 2 to 4 , in the present embodiment, step S130 further includes step S133.

[0139] Step S133: When the power unit is in the cold engine operating mode, start the warm engine system 400 at preset intervals. When the warm engine system 400 is started, the controller can detect whether the temperature of the coolant reaches the second preset standard through the engine temperature sensor 411. When the coolant temperature does not reach the second preset standard, the warm engine system 400 stops running. When the coolant temperature reaches the second preset standard, the controller controls the power unit to switch to the hybrid operating mode, and the cold engine system 300, the warm engine system 400, the heat exchange system 200, and the combustion system 100 start running.

[0140] After the engine 106 operates in the cold engine operating mode, the temperature of the engine 106 gradually rises. When the warm engine system 400 is temporarily started and the engine temperature sensor 411 detects that the temperature of the coolant reaches the second preset standard but does not reach the first preset standard, the controller controls the warm engine system 400 to continue starting, so that the power unit switches from the cold engine operating mode to the hybrid operating mode, thereby making full use of the heat generated when the engine 106 burns and does work, and improving the energy utilization rate during ship operation.

[0141] When the warm engine system 400 is temporarily started and the temperature of the coolant detected by the engine temperature sensor 411 does not reach the second preset standard, the controller controls the warm engine system 400 to shut down, so that the power unit maintains the cold engine operating mode.

[0142] After the warm engine system 400 is shut down for a preset time, the controller controls the warm engine system 400 to be temporarily started again to detect whether the coolant temperature reaches the second preset standard.

[0143] Refer to Figures 2 to 4 , in this embodiment, step S130 further includes step S134.

[0144] Step S134: When the controller detects through the engine temperature sensor 411 that the temperature of the coolant reaches the first preset standard, the controller controls the power unit to switch to the warm engine operating mode, and the warm engine system 400, the heat exchange system 200, and the combustion system 100 start running, and the cold engine system 300 stops running.

[0145] When the engine 106 burns and does work for a period of time, the temperature of the engine 106 rises to the first preset standard, and the controller controls the ship power unit to switch to the warm engine operating mode, so as to make full use of the waste heat generated by the engine 106 doing work, improve the energy utilization efficiency, and reduce the ship use cost. And it can reduce the temperature of the engine 106 and ensure the stable and safe operation of the engine 106.

[0146] Figure 5 It is a schematic flowchart of steps S1341 and S1342 of the control method of the present invention.

[0147] Refer to Figures 2 to 5 In this embodiment, step S134 further includes step S1341.

[0148] 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 its power until the power of the compressor 322 is reduced to the following level, and then the cold machine system 300 stops operating, and the power device switches to the hot machine working mode.

[0149] When the power device switches from the hybrid working mode to the hot machine working mode, the controller controls the compressor 322 to gradually reduce its power until the power of the compressor 322 is reduced below the preset power, and then stops the operation of the cold machine system 300. On the one hand, it can make full use of the heat in the cold machine system 300 to avoid energy waste. On the other hand, it can protect the cold machine system 300 and avoid the generation of thermal stress in structures such as the compressor 322 and the transfer heat exchanger due to sudden stop, thus avoiding damage to structures such as the compressor 322 and the transfer heat exchanger from deformation and cracking, and ensuring the safety and reliability of the cold machine system 300.

[0150] In some embodiments, the preset power is 25% of the rated power. When the power of the compressor 322 is reduced below 25% of the rated power of the compressor 322, the cold machine system 300 can stop operating.

[0151] Refer to Figures 2 to 5 In this embodiment, the combustion system 100 includes a normal temperature transfer tank 102 and a second fuel pump 142. The heat exchange system 200 is provided with a heat exchange liquid storage tank 203, a heat exchange liquid driving pump 211 and a heat exchange temperature sensor 214. The hot machine system 400 includes a cooling structure 401 and a cooling liquid driving pump 413. The controller is electrically connected to the second fuel pump 142, the heat exchange liquid driving pump 211 and the cooling liquid driving pump 413.

[0152] Step S134 further includes step S1342.

[0153] Step S1342: When the power device is in the hot machine working mode, the controller is electrically connected to the heat exchange liquid driving pump 211, the cooling liquid driving pump 413 and the heat exchange temperature sensor 214. 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.

[0154] When the power device is in the hot machine working mode, since the heat generated by the working powers of the engine 106 is different, the heat that the cooling system needs to absorb is also different. By adjusting the power of the cooling liquid driving pump 413 and the heat exchange liquid driving pump 211, the controller can adjust the cooling effect of the cooling structure 401 in real time to ensure the safe and stable operation of the engine 106.

[0155] Figure 6 It is a schematic flowchart of step S140 of the control method of the present invention.

[0156] Refer to Figures 2 to 6 , in this embodiment, when the ship is switching fuels or restarting the engine 106 after a short stop, the temperature inside the engine 106 still reaches the first preset standard. The control method further includes step S140.

[0157] Step S140: After the engine 106 has a short shutdown, the controller controls the warm engine system 400 and the heat exchange system 200 to start. The controller detects the temperature information of the coolant through the engine temperature sensor 411; when the temperature of the coolant reaches the first preset standard, the controller controls the power device to switch to the warm engine working mode.

[0158] When the engine 106 is restarted again after a short shutdown or after fuel switching, the controller starts the warm engine system 400 and the heat exchange system 200, and determines whether the temperature of the coolant is greater than the first preset standard based on the temperature information of the coolant detected by the engine temperature sensor 411.

[0159] When the temperature of the coolant is greater than the first preset standard, the controller controls the power device to switch to the warm engine working mode to make full use of the heat generated by the work of the engine 106 and improve the energy utilization efficiency. Moreover, it can effectively improve the working efficiency of the power device.

[0160] 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.

[0161] Although the present application has been described with reference to several exemplary embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the present application can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above-described embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A marine LNG power plant, characterized in that, Comprising: A combustion system, which includes a vaporizer and an engine; The vaporizer is used to vaporize liquid natural gas into natural gas; the engine is connected to the vaporizer, and the engine is used to receive the natural gas and burn to do work; A heat exchange system, in which a heat exchange medium flows, and the heat exchange system is connected to the vaporizer to be able to transfer the heat in the heat exchange medium to the vaporizer to vaporize the liquid natural gas therein; A chiller system, in which a heat supply medium flows, the chiller system can heat up the heat supply medium, and can input the heat of the heat supply medium into the heat exchange system to heat the heat exchange medium; A heat engine system, in which a coolant flows, and the coolant is used to absorb the heat of the engine; the coolant can transfer the heat into the heat exchange system to heat the heat exchange medium.

2. The power device according to claim 1, characterized in that, The heat exchange system includes a first heat exchanger and a second heat exchanger connected in communication, and the first heat exchanger is located upstream of the second heat exchanger; the first heat exchanger is connected to the chiller system so that the heat exchange medium absorbs the heat of the heat supply medium through the first heat exchanger; the second heat exchanger is connected to the vaporizer and is located upstream of the vaporizer; the second heat exchanger is connected to the heat engine system so that the heat exchange medium absorbs the heat in the coolant through the second heat exchanger.

3. The power device according to claim 1 or 2, characterized in that, The chiller system includes a heating circuit and a transfer circuit; the heat supply medium includes a first heat supply medium and a second heat supply medium; The first heat supply medium flows in the heating circuit; the heating circuit can evaporate and then compress the first heat supply medium to form high-temperature steam; The second heat supply medium flows in the transfer circuit, the transfer circuit is connected to the heating circuit and the heat exchange system, and the second heat supply medium can absorb the heat in the high-temperature steam and transfer the heat to the heat exchange medium.

4. The power device according to claim 3, characterized in that, The transfer circuit includes at least one transfer heat exchanger; The heating circuit includes an evaporator and at least one compressor connected in sequence, the evaporator can evaporate the first heat supply medium to form steam, the compressor can compress the steam to form high-temperature steam, and the compressor is located upstream of the adjacent transfer heat exchanger to be able to input the high-temperature steam into the transfer heat exchanger to exchange heat with the second heat supply medium.

5. The power device according to claim 4, characterized in that, The transfer circuit further includes a transfer liquid storage tank and a transfer liquid pump, the transfer liquid storage tank is connected to the transfer heat exchanger, and the transfer liquid storage tank is used to accommodate the second heat supply medium; The transfer liquid pump is arranged between the transfer liquid storage tank and the transfer heat exchanger to pump the second heat supply medium in the transfer liquid storage tank into the transfer heat exchanger.

6. The power device according to claim 5, characterized in that, The transfer circuit further includes 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 to obtain the temperature information of the second heat supply medium.

7. The power device according to claim 2, characterized in that, The heat engine system further includes a cooling structure and an engine temperature sensor. The cooling structure is disposed on the engine, and the coolant circulates within the cooling structure. The cooling structure is connected to the second heat exchanger to input the coolant into the second heat exchanger. The engine temperature sensor is disposed between the cooling structure and the second heat exchanger and is configured to detect the temperature information of the refrigerant output from the cooling structure.

8. The power device according to claim 2, characterized in that, The heat exchange system further includes a heat exchange liquid storage tank and a heat exchange liquid driving pump. The heat exchange liquid storage tank is disposed between the second heat exchanger and the vaporizer and is used to store the heat exchange agent. The heat exchange liquid driving pump is disposed at the output end of the liquefied liquid storage tank to output the heat exchange agent in the heat exchange liquid storage tank into the vaporizer.

9. The power device according to claim 1, characterized in that, A first control valve is provided on the heat exchange system, a second control valve is provided on the cold machine system, and a third control valve is provided on the heat engine system. The power device further includes a controller, which is electrically connected to the first control valve, the second control valve, and the third control valve to be able to control the opening and closing of the first control valve, the second control valve, and the third control valve.

10. The power device according to claim 1, characterized in that, The combustion system further includes a normal temperature transfer tank, which is used to accommodate the liquefied natural gas and raise the temperature of the liquefied natural gas. The normal temperature transfer tank is connected to the input end of the vaporizer to be able to input the stored liquefied natural gas into the vaporizer for vaporization. And / or, the combustion system further includes a voltage stabilizer and a gas-liquid separator. The voltage stabilizer is connected to the output end of the vaporizer to receive the natural gas vaporized and output by the vaporizer. The gas-liquid separator is connected to the output end of the voltage stabilizer to separate the residual liquefied natural gas in the natural gas.

11. A control method for a ship's LNG power plant, characterized in that, The control method is used to control the ship LNG power device according to any one of claims 1 to 10. The control method includes: The cold machine system can raise the temperature of the heat supply agent and heat the heat exchange agent through the heat supply agent. The coolant in the heat engine system can absorb the heat generated when the engine burns and does work, and transfer the heat to the heat exchange agent. After the heat exchange agent in the heat exchange system is heated, the heat exchange agent can exchange heat with the liquefied natural gas through the vaporizer, so that the liquefied natural gas is heated and vaporized to form natural gas and is transported into the engine for combustion.

12. The control method according to claim 11, characterized in that, The heat engine system is provided with the engine temperature sensor, and the engine temperature sensor is used to detect the temperature information of the coolant flowing through the engine. The power device further includes a controller, which is electrically connected to the engine temperature sensor to obtain the detected temperature information of the coolant. The controller can be electrically connected to the cold machine system, the heat engine system, the heat exchange system, and the combustion system. The cold machine system, the heat exchange system, and the combustion system can be started and operated to form a cold machine working mode. The cold engine system, the hot engine system, the heat exchange system and the combustion system can be started and operated to form a hybrid working mode; The hot engine system, the heat exchange system and the combustion system can be started and operated to form a hot engine working mode; The controller can control the switching among the cold engine working mode, the hybrid working mode and the hot engine working mode according to the temperature information of the engine temperature sensor.

13. The control method according to claim 12, characterized in that, A first preset standard is preset in the controller; When the engine temperature sensor detects that the temperature of the coolant reaches the first preset standard, the controller controls the compressor to gradually reduce its power. After the power of the compressor is reduced below the preset power, the cold engine system stops operating and the power device switches to the hot engine working mode.

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