Automatic control system for ammonia fuel supply

Abstract

The invention provides an automatic control system for ammonia fuel supply, which belongs to the technical field of intelligent equipment operation monitoring and comprises an unloading crane pipe, an unloading compressor, a liquid ammonia storage tank, a low-pressure pump, a high-pressure pump, a first heat exchanger, a duplex filter and a controller, the unloading crane pipe is communicated with a filling port of the liquid ammonia storage tank, and the unloading compressor is communicated with a gas outlet of the liquid ammonia storage tank; the low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter are sequentially connected to a liquid ammonia outlet of the liquid ammonia storage tank through pipelines, and an outlet valve is arranged at the liquid ammonia outlet of the liquid ammonia storage tank; and the controller is used for controlling the working modes of the low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter so as to adjust the pressure, the temperature and the purity of the output ammonia fuel to target ranges. The purpose of providing ammonia fuel with pressure, temperature and purity meeting requirements for target equipment can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent equipment operation monitoring, and in particular to an automatic control system for ammonia fuel supply. Background Art

[0002] Ammonia fuel has broad application prospects in ships, especially in the context of achieving zero carbon emission goals, ammonia fuel is likely to become an important fuel option for the shipping industry. With the advancement of technology and changes in international shipping regulations, the use of ammonia fuel will become more popular. The continuous advancement of research at home and abroad will contribute to the green transformation of the global shipping industry. Ammonia is one of the most promising new energy fuels in the current shipping industry's decarbonization route. How to efficiently and conveniently store and use ammonia fuel on ships while ensuring safety is a huge challenge facing the shipping industry.

[0003] With the application and promotion of dual-fuel engines and new energy fuels, the ship operation costs have been greatly reduced while reducing pollutant emissions. Due to the special physical and chemical properties of ammonia, the existing fuel supply systems such as diesel, LNG, and methanol are not suitable, so it is necessary to design and develop an ammonia fuel supply system to achieve the purpose of providing the target equipment with ammonia fuel that meets the pressure, temperature, and purity requirements. Summary of the invention

[0004] In view of this, it is necessary to provide an automatic control system for the supply of ammonia fuel to achieve the purpose of providing ammonia fuel with pressure, temperature and purity that meet the requirements to the target equipment.

[0005] In order to solve the above problems, the present invention provides an automatic control system for ammonia fuel supply, including: an unloading crane pipe, an unloading compressor, a liquid ammonia storage tank, a low-pressure pump, a high-pressure pump, a first heat exchanger, a duplex filter and a controller; The unloading crane pipe is connected to the filling port of the liquid ammonia storage tank, and the unloading compressor is connected to the gas outlet of the liquid ammonia storage tank; The low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter are sequentially connected to the liquid ammonia outlet of the liquid ammonia storage tank through pipelines, and an outlet valve is provided at the liquid ammonia outlet of the liquid ammonia storage tank; The controller is used to control the working modes of the low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter to adjust the pressure, temperature and purity of the output ammonia fuel to a target range.

[0006] In a possible implementation, the automatic control system for ammonia fuel supply further includes: an ethylene glycol expansion water tank, an ethylene glycol pump, a heater, a cooler, and a chiller; The heater and the cooler are both connected to the first heat exchanger through the ethylene glycol pump, and the ethylene glycol expansion water tank is connected to the first heat exchanger; The chiller is in communication with the cooler.

[0007] In a possible implementation, the ethylene glycol pump includes: a first ethylene glycol pump and a second ethylene glycol pump; The input ends of the first ethylene glycol pump and the output ends of the second ethylene glycol pump are connected to each other, forming a first loop; The heater and the cooler are both in communication with the first heat exchanger through the first circuit.

[0008] In a possible implementation, the automatic control system for ammonia fuel supply further includes: a first pressure sensor disposed between the first loop and the heater and the cooler; The controller is also used to receive the ethylene glycol outlet pressure collected by the first pressure sensor, and control the high-pressure pump, the low-pressure pump, the first ethylene glycol pump and the second ethylene glycol pump to stop working when the ethylene glycol outlet pressure is greater than a first target pressure threshold.

[0009] In a possible implementation, a filling valve is provided on the pipeline between the unloading crane pipe and the liquid ammonia storage tank, and a gas phase pipe valve is provided on the pipeline between the unloading compressor and the gas outlet of the liquid ammonia storage tank; The controller is also used to control the opening of the filling valve and the gas phase pipe valve in the unloading mode.

[0010] In a possible implementation, the low-pressure pump includes: a first low-pressure pump and a second low-pressure pump, and the high-pressure pump includes: a first high-pressure pump and a second high-pressure pump; the input ends of the first low-pressure pump and the second low-pressure pump are interconnected and the output ends are interconnected to form a second loop, and the input ends of the first high-pressure pump and the second high-pressure pump are interconnected and the output ends are interconnected to form a third loop; The second circuit, the third circuit, the first heat exchanger and the duplex filter are connected in sequence and then connected to the liquid ammonia outlet of the liquid ammonia storage tank; Furthermore, the output end of the second circuit is also connected to the input end of the first heat exchanger through a bypass return valve; The controller is also used to control the filling valve, the outlet valve and the bypass reflux valve to open after controlling the low-pressure pump to start, and to adjust the liquid ammonia flow by controlling the bypass reflux valve.

[0011] In a possible implementation, in the automatic control system for ammonia fuel supply, the duplex filter comprises: a first duplex filter and a second duplex filter; The input ends of the first duplex filter and the second duplex filter are both connected to the output end of the first heat exchanger, and the output ends of the first duplex filter and the second duplex filter are provided with a second pressure sensor; The controller is further configured to receive the liquid ammonia pressure difference between the outputs of the first double filter and the second double filter collected by the second pressure sensor, and to issue a reminder to replace the double filter element when the liquid ammonia pressure difference is greater than a second target pressure threshold.

[0012] In a possible implementation, the automatic control system for ammonia fuel supply further includes: an injector cooling water module consisting of a cooling water tank, a second heat exchanger and a cooling water pump connected in sequence, wherein the injector cooling water module is used to provide cooling water to the ammonia injector.

[0013] In a possible implementation, the automatic control system for ammonia fuel supply further includes: an ammonia collection tank and a first washing cabinet; The input end of the ammonia collection tank is connected to the liquid ammonia storage tank through a discharge valve, and the output end of the ammonia collection tank is connected to the first washing cabinet.

[0014] In a possible implementation, the automatic control system for ammonia fuel supply further includes: a gas-liquid separation tank and a second washing cabinet; The input end of the gas-liquid separation tank is communicated with the output end of the low-pressure pump, and the output end of the gas-liquid separation tank is communicated with the second washing cabinet.

[0015] The beneficial effects of adopting the above-mentioned implementation method are as follows: the automatic control system for ammonia fuel supply provided by the present invention fills the filling port of the liquid ammonia storage tank with liquid ammonia fuel through the unloading crane pipe. When filling the liquid ammonia fuel, the pressure in the liquid ammonia storage tank is ensured to be within an appropriate range through the operation of the unloading compressor, thereby ensuring that the unloading crane pipe smoothly fills the liquid ammonia storage tank with liquid ammonia fuel; when the liquid ammonia storage tank outputs ammonia fuel to the outside, the pressure of the output ammonia fuel is adjusted by controlling the working modes of the low-pressure pump and the high-pressure pump, so that the pressure of the output ammonia fuel meets the requirement, the output ammonia fuel is heat exchanged by the first heat exchanger, so that the temperature of the output ammonia fuel meets the requirement, and the ammonia fuel is filtered by the double filter, so that the purity of the output ammonia fuel meets the requirement. Therefore, the automatic control system for ammonia fuel supply provided by the present invention can achieve the purpose of providing ammonia fuel whose pressure, temperature and purity all meet the requirements to the target equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 A principle block diagram of an embodiment of an automatic control system for ammonia fuel supply provided by the present invention; Figure 2 A partial structural schematic diagram of another embodiment of the automatic control system for ammonia fuel supply provided by the present invention; Figure 3 A partial structural schematic diagram of another embodiment of the automatic control system for ammonia fuel supply provided by the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present application, unless otherwise specified, “plurality” means two or more than two.

[0020] The terms "including" and "having" and any variations thereof in the embodiments of the present invention are intended to cover non-exclusive inclusions. For example, a process, method, apparatus, product or equipment comprising a series of steps or modules is not necessarily limited to those steps or modules clearly listed, but may include other steps or modules not clearly listed or inherent to these processes, methods, products or equipment.

[0021] The naming or numbering of the steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical sequence indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effects can be achieved.

[0022] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] like Figure 1 As shown, the present invention provides an automatic control system for ammonia fuel supply, comprising: an unloading crane 101, an unloading compressor 102, a liquid ammonia storage tank 103, a low-pressure pump 104, a high-pressure pump 105, a first heat exchanger 106, a duplex filter 107 and a controller (not shown in the figure); The unloading crane pipe 101 is connected to the filling port of the liquid ammonia storage tank 103, and the unloading compressor 102 is connected to the gas outlet of the liquid ammonia storage tank 103; The low-pressure pump 104, the high-pressure pump 105, the first heat exchanger 106 and the double filter 107 are sequentially connected to the liquid ammonia outlet of the liquid ammonia storage tank 103 through pipelines, and the liquid ammonia outlet of the liquid ammonia storage tank 103 is provided with an outlet valve; The controller is used to control the working modes of the low-pressure pump 104, the high-pressure pump 105, the first heat exchanger 106 and the duplex filter 107 to adjust the pressure, temperature and purity of the output ammonia fuel to a target range.

[0024] It can be understood that the controller provided by the present invention can be a PLC (Programmable Logic Controller).

[0025] The unloading crane pipe 101 is connected to the filling port of the liquid ammonia storage tank 103, and liquid ammonia fuel can be added to the liquid ammonia storage tank 103 through the unloading crane pipe 101. The unloading compressor 102 is connected to the gas outlet of the liquid ammonia storage tank 103. When filling the liquid ammonia fuel, the unloading compressor 102 can be controlled to start working to ensure the internal air pressure of the liquid ammonia storage tank 103 when filling the liquid ammonia fuel, thereby smoothly realizing the filling of liquid ammonia fuel.

[0026] The controller ensures that the pressure of the liquid ammonia delivered by the liquid ammonia storage tank 103 meets the requirements by controlling the operation of the low-pressure pump 104 and the high-pressure pump 105, and performs heat exchange on the ammonia fuel output from the liquid ammonia storage tank 103 to ensure that the temperature of the ammonia fuel meets the requirements by controlling the operation of the first heat exchanger 106, and filters the ammonia fuel to ensure that the purity of the ammonia fuel meets the requirements by controlling the operation of the double filter 107, thereby ensuring that the pressure, temperature and purity of the supplied ammonia fuel all meet the requirements.

[0027] By analyzing the characteristics of ammonia fuel, the present invention designs a full-process ammonia fuel supply system for a new ammonia fuel engine, and develops an automatic control and monitoring system for ammonia fuel supply based on PLC and a host computer. The system includes an ammonia fuel filling, storage, transportation, and supply system. Each subsystem has its corresponding high-frequency sensors for temperature, pressure, flow, etc., and control valve components such as solenoid valves, bypass valves, and safety valves, which realize automatic control and comprehensive monitoring of each process and subsystem, and improve the convenience and efficiency of the system while strictly ensuring the safety of the system.

[0028] In some embodiments, Figure 2 As shown, the automatic control system for ammonia fuel supply also includes: an ethylene glycol expansion water tank, an ethylene glycol pump, a heater, a cooler and a chiller; The heater and the cooler are both connected to the first heat exchanger 106 through the ethylene glycol pump, and the ethylene glycol expansion water tank is connected to the first heat exchanger 106; The chiller is in communication with the cooler.

[0029] It is understandable that the glycol expansion water tank, glycol pump, heater, cooler and chiller constitute the glycol heat exchange system, and the glycol heat exchange system has two modes, heating and cooling. The control system automatically switches the mode according to the comparison between the heat exchanger inlet temperature and the set temperature. When the glycol liquid level is low, the high-pressure pump 105, the low-pressure pump 104 and the glycol pump can be turned off. When the glycol liquid level is high, a liquid ammonia leak can be indicated.

[0030] In some embodiments, the glycol pump comprises: a first glycol pump and a second glycol pump; The input ends of the first ethylene glycol pump and the output ends of the second ethylene glycol pump are connected to each other, forming a first loop; The heater and the cooler are both in communication with the first heat exchanger 106 via the first circuit.

[0031] It can be understood that the outlets of the first ethylene glycol pump and the second ethylene glycol pump are connected to the heater and the cooler, and a pressure sensor is provided between the first ethylene glycol pump and the second ethylene glycol pump and the heater and the cooler. The pressure sensor can be used to monitor the ethylene glycol outlet pressure, and when the ethylene glycol outlet pressure is high, an alarm is issued, and the high-pressure pump 105, the low-pressure pump 104 and the ethylene glycol pump are controlled to stop working.

[0032] In some embodiments, the automatic control system for ammonia fuel supply further includes: a first pressure sensor disposed between the first loop and the heater and the cooler; The controller is also used to receive the ethylene glycol outlet pressure collected by the first pressure sensor, and control the high-pressure pump 105, the low-pressure pump 104, the first ethylene glycol pump and the second ethylene glycol pump to stop working when the ethylene glycol outlet pressure is greater than a first target pressure threshold.

[0033] It is understandable that when the ethylene glycol outlet pressure is high, it indicates that there may be a fault in the ethylene glycol heat exchange system. At this time, it is necessary to control the high-pressure pump 105, the low-pressure pump 104, the first ethylene glycol pump and the second ethylene glycol pump to stop working to avoid the temperature of the supplied ammonia fuel not meeting the requirements.

[0034] In some embodiments, a filling valve is provided on the pipeline between the unloading crane pipe 101 and the liquid ammonia storage tank 103, and a gas phase pipe valve is provided on the pipeline between the unloading compressor 102 and the gas outlet of the liquid ammonia storage tank 103; The controller is also used to control the opening of the filling valve and the gas phase pipe valve in the unloading mode.

[0035] It can be understood that the controller controls the filling valve and the gas phase pipe valve to open in the unloading mode, and the unloading crane pipe 101 starts to fill the liquid ammonia fuel into the liquid ammonia storage tank 103, while also ensuring that the gas pressure inside the liquid ammonia storage tank 103 meets the requirements, so that the liquid ammonia fuel can be smoothly filled into the liquid ammonia storage tank 103.

[0036] In some embodiments, the low-pressure pump 104 includes: a first low-pressure pump 104 and a second low-pressure pump 104, and the high-pressure pump 105 includes: a first high-pressure pump 105 and a second high-pressure pump 105; the input ends of the first low-pressure pump 104 and the second low-pressure pump 104 are interconnected and the output ends are interconnected to form a second loop, and the input ends of the first high-pressure pump 105 and the second high-pressure pump 105 are interconnected and the output ends are interconnected to form a third loop; The second circuit, the third circuit, the first heat exchanger 106 and the double filter 107 are connected in sequence and then connected to the liquid ammonia outlet of the liquid ammonia storage tank 103; Furthermore, the output end of the second circuit is also connected to the input end of the first heat exchanger 106 through a bypass return valve; The controller is also used to control the filling valve, the outlet valve and the bypass reflux valve to open after controlling the low-pressure pump 104 to start, and to adjust the liquid ammonia flow by controlling the bypass reflux valve.

[0037] It is understandable that the low pressure pump 104 is turned on in the upper computer control interface, and the control program automatically turns on the low pressure pump 104 after it is started. Figure 2The top filling valve ESV001 and the tank outlet valve ESV003 of the liquid ammonia storage tank 103 are shown, and then the bypass return valve PSV001 is opened to adjust the liquid ammonia flow; the ammonia fuel is cooled or heated by the heat exchanger E101, and the temperature is accurately controlled according to the host fuel demand. The temperature setting value can be changed on the control interface and displayed in real time; the ethylene glycol heat exchange system has two modes, heating and cooling. The control system automatically compares the heat exchanger inlet temperature with the set temperature and automatically switches the mode. The control interface can select the high-pressure pump 105 and control the start and stop, and automatically open the bypass return valve.

[0038] In some embodiments, the duplex filter 107 includes: a first duplex filter 107 and a second duplex filter 107; The input ends of the first duplex filter 107 and the second duplex filter 107 are both connected to the output end of the first heat exchanger 106, and the output ends of the first duplex filter 107 and the second duplex filter 107 are provided with second pressure sensors; The controller is further used to receive the liquid ammonia pressure difference between the outputs of the first double filter 107 and the second double filter 107 collected by the second pressure sensor, and to issue a reminder to replace the filter element of the double filter 107 when the liquid ammonia pressure difference is greater than a second target pressure threshold.

[0039] It is understandable that when the liquid ammonia pressure difference is greater than the second target pressure threshold, it is possible that the filter element of the first double filter 107 is faulty or the filter element of the second double filter 107 is faulty. In this case, it is necessary to manually determine the faulty filter element and replace it.

[0040] In some embodiments, the automatic control system for ammonia fuel supply further includes: an injector cooling water module consisting of a cooling water tank, a second heat exchanger and a cooling water pump connected in sequence, wherein the injector cooling water module is used to provide cooling water to the ammonia injector.

[0041] It is understood that the main purpose of the injector cooling water module is to cool the ammonia injectors when the engine is running in diesel mode. When the engine is running in diesel mode, the ammonia injector cooling water is circulated from the ammonia injector cooling water buffer tank to the ammonia injectors and then returned to the cooling water buffer tank in a closed loop. In addition, the injector cooling water is used during the purge process to remove vapors after the liquid purge.

[0042] The ejector cooling water system is a closed-loop water system with an independent electronic control system. During operation, the ejector cooling pump supplies cooling water to the engine according to control instructions. During the process, pressure control is performed through the ejector cooling pump and bypass reflux according to pressure requirements. The pressure replenishment and pressure relief procedures of the cooling water tank are automatically executed according to the set value. All remote control valves and pumps in the system can be selected in manual operation mode and manually operated separately on the control interface.

[0043] In some embodiments, the automatic control system for ammonia fuel supply further includes: an ammonia collection tank and a first washing cabinet; The input end of the ammonia gas collecting tank is connected to the liquid ammonia storage tank 103 through a discharge valve, and the output end of the ammonia gas collecting tank is connected to the first washing cabinet.

[0044] It is understandable that when the first washing cabinet is in operation, the spray tower sprays fresh water, the control valve controls the fresh water flow, and the sensor measures and feeds back the actual flow. Figure 3 As shown, TIT501 monitors the temperature of the gas-liquid separation tank, and starts water spraying when the temperature is higher than the alarm; PIT501 / 502 respectively controls and detects the pressure of the gas-liquid separation tank; LIT501 detects the liquid level of the gas-liquid separation tank, opens Q301 when the liquid level is higher, and closes Q301 when the liquid level is lower; LIT502 detects the liquid level of the washing cabinet, reminds to discharge ammonia water when the alarm is higher, and reminds to add fresh water when the alarm is lower.

[0045] In some embodiments, the automatic control system for ammonia fuel supply further includes: a gas-liquid separation tank and a second washing cabinet; The input end of the gas-liquid separation tank is communicated with the output end of the low-pressure pump 104 , and the output end of the gas-liquid separation tank is communicated with the second washing cabinet.

[0046] It is understandable that after fuel switching or emergency shutdown, nitrogen is used to purge the main engine, and the gas-liquid mixture refluxed from the main engine needs to be collected and processed. The designed residual liquid collection and processing system of the ammonia fuel station area is mainly composed of a gas-liquid separation tank and an ammonia washing unit. The gas-liquid separation tank collects the liquid ammonia purged from the main engine in the first stage, and nitrogen-seales it with high-pressure nitrogen to keep it in a liquid state, and outputs the liquid ammonia to the inlet of the high-pressure pump 105 for recycling when the liquid level is high.

[0047] In some embodiments, the structural design and sensor layout of the automatic control system for ammonia fuel supply are as follows: Figure 2 and Figure 3 As shown, the functional composition, control logic and monitoring instructions of each subsystem are introduced in detail below.

[0048] Ammonia fuel filling and storage system: The main function of the filling and storage system is to realize the transfer of ammonia fuel from the filling station to the storage tank and to safely store ammonia fuel. The main components are the unloading crane pipe 101, the unloading compressor 102, the ammonia fuel storage tank (i.e., the liquid ammonia storage tank 103), the solenoid valve, the safety valve and other components. Liquid ammonia is transported by tank trucks. After the site is connected to the unloading crane pipe 101, the four-way valve of the unloading compressor 102 is switched to the unloading mode on the upper computer control interface, the bottom filling valve ESV002 and the gas phase pipe valve ESV006 of the storage tank are opened, and then the main filling valves ESV005 and ESV004 of the storage tank are opened. The gas phase pipe valve of the tank truck remains unobstructed, and the unloading work is completed by pressurizing the tank truck with the unloading compressor 102.

[0049] LIT001, PIT001, PIT002, TIT001, TIT002, TIT003 and other related sensors are displayed in real time on the host computer interface, and a pop-up alarm will be displayed when the set range is exceeded. LIT001 is the liquid level sensor of the liquid ammonia storage tank 103, which has high, low, higher and lower liquid level alarms. When the higher liquid level alarm occurs, the main filling valve ESV004 and the compressor are automatically closed, and when the lower liquid level alarm occurs, the pressure pump is automatically stopped; PIT001 is a pressure sensor, which monitors the pressure of the storage tank, and has high, low, higher and lower pressure alarms. When the higher pressure alarm occurs, the main filling valve, the unloading compressor 102 and the high and low pressure pumps 104 are automatically closed, and when the lower pressure alarm occurs, the high and low pressure pumps 104 are automatically closed; PIT002 monitors the compressor outlet pressure, and automatically stops the compressor when the higher pressure alarm occurs to prevent accidents caused by excessive pressure; TIT is a temperature sensor, which monitors the temperature of the liquid ammonia storage tank 103, and has high, low, higher and lower temperature alarms. When the higher temperature alarm occurs, the water spray is automatically started.

[0050] Ammonia fuel delivery and supply system: The ammonia fuel delivery and supply system is mainly composed of low-pressure pump 104, high-pressure pump 105, electric heater, heat exchanger, ethylene glycol pump, duplex filter 107, bypass valve, solenoid valve and other components. According to the main engine inlet fuel demand, the ammonia fuel pressure, temperature and purity are adjusted to the main engine specified range. The power booster equipment is set to one for use and one for backup, and automatically switches to the backup equipment when one fails. Turn on the low-pressure pump 104 in the upper computer control interface. After the low-pressure pump 104 is started, the control program automatically opens the top filling valve ESV001 and the tank outlet valve ESV003 of the liquid ammonia storage tank 103, and then opens the bypass return valve PSV001 to adjust the liquid ammonia flow; the ammonia fuel relies on the heat exchanger E101 for cooling or heating, and the temperature is accurately controlled according to the main engine fuel demand. The temperature setting value can be changed on the control interface and displayed in real time; the ethylene glycol heat exchange system has two modes: heating and cooling. The control system automatically compares the heat exchanger inlet temperature with the set temperature and automatically switches the mode. The control interface can select the high-pressure pump 105 and control the start and stop, and automatically open the bypass return valve.

[0051] The corresponding sensors of the liquid ammonia transportation and supply system are displayed in real time on the host computer interface, and a pop-up alarm will be issued when the set range is exceeded. High, higher, low, and lower correspond to different logics respectively. PIT011 monitors the outlet pressure of the low-pressure pump 104, and PIT012 is displayed on the control interface, and the outlet pressure of the low-pressure pump 104 can be set; TIT011 monitors the inlet temperature of the high-pressure pump 105, PIT013-PIT001 is the inlet pressure difference of the high-pressure fuel pump, PIT014 monitors the outlet pressure of the high-pressure pump 105, and fully opens the bypass valve PCV011 when a higher pressure alarm occurs; TIT013 / 014 are temperature sensors at the outlet of the liquid ammonia heat exchanger, which are used to control and monitor the outlet temperature respectively; DPIT011 is the pressure difference of the duplex filter 107, and when a higher alarm occurs, it reminds you to replace the filter element; FIT011 is a mass flow monitor; TIT015 monitors and controls the outlet temperature of ethylene glycol; TIT016 monitors the return water temperature of ethylene glycol; PIT015 monitors the outlet pressure of ethylene glycol, and automatically stops the high and low pressure pumps 104 and the ethylene glycol pump when a higher pressure alarm occurs. LS011 monitors the glycol liquid level. When the lower liquid level alarm occurs, the high and low pressure pumps 104 and the glycol pump are stopped. When the higher liquid level occurs, the upper computer interface is alerted of liquid ammonia leakage.

[0052] Ammonia fuel valve group unit: a pipeline system is set up to safely purge and degas each fuel tank and add ammonia fuel after purge. FVU is used to adjust and ensure system safety. It is mainly composed of solenoid valves, filters, flow meters, safety valves and various sensors. The valve group is divided into normally closed and normally open valves. Before each ammonia supply, the valve group unit needs to be leak tested. After receiving the control system signal, the corresponding valve is closed. The pressure does not exceed the set value within the specified time. The test is passed. The control interface is set up separately. The debugging interface, in the debugging mode, the valve can be manually controlled, and each gas valve can be switched on and off separately. The control interface also needs to display the open and closed status of each valve. When the pneumatic valve position feedback is inconsistent with the instruction, the control system valve fault alarm is issued, and the FVU enters the initial state.

[0053] PIT021 / 022 monitors the inlet and outlet pressures of the supply pipe respectively; TIT021 / 022 monitors the inlet temperatures of the supply pipe and the return pipe respectively; when the system is operating normally, the valve is in the initial state. Before each ammonia supply, the system will perform a leakage test, Q102 / 103 / 104 will be closed, and if the pressure change of PIT2601 does not exceed the set value within the specified time, it is considered that the system is well sealed, and then Q102 / 103 will be opened to start supplying ammonia; when the main engine is shut down in an emergency in ammonia fuel mode, or switched from ammonia fuel to other fuels, Q108 / 110 will be opened, Q109 will be closed, and the nitrogen system will start to purge the FVU pipeline and the main engine; when the main engine is running in diesel mode, Q118 / 119 / 122 / 123 will be opened, and the cooling water system will cool the ammonia injector.

[0054] Nitrogen supply system: If the engine is shut down in emergency in ammonia fuel mode, or suddenly shuts down during operation in ammonia fuel mode, measures should be taken to purge the exhaust pipe before restarting the engine, and the purge gas should be properly handled. The purpose of the designed inert gas supply system is to provide inert gas for the ammonia storage and supply system. When the main engine is converted from ammonia fuel mode to fuel mode or from fuel mode to ammonia fuel mode, the nitrogen purge of the main engine and the supply pipeline is mainly completed by controlling different valve groups in the FVU.

[0055] The system provided by the present invention is provided with two sets of nitrogen supply devices, which are respectively located in the ammonia station area and the valve group unit area. The nitrogen supply system in the ammonia station area needs to detect the pressure. In addition to pressure monitoring, the valve group unit system also needs to adjust the pressure value and nitrogen heater according to the host demand, and open and close different valves according to different demands. When a strong nitrogen purge command is received, Q201 is turned on to supply nitrogen until the strong nitrogen purge command is revoked; when a weak nitrogen supply command is received, Q202 is turned on to supply weak nitrogen until the weak nitrogen purge command is revoked; when a cooling water tank pressure replenishment command is received, Q203 is turned on to supply nitrogen until the cooling water tank pressure replenishment command is revoked; when an engine nitrogen supply command is received, Q204 is turned on to supply nitrogen until the engine nitrogen supply command is revoked. TIT031 monitors the nitrogen purge temperature, and PIT031 / 032 monitors the FVU nitrogen supply pressure and the ammonia station area nitrogen supply pressure respectively.

[0056] Ammonia Injector Cooling Water System: The designed Ammonia Injector Cooling Water System (AICWS) includes an Ammonia Injector Cooling Water Surge Tank with a heat exchanger (cooling element), and an Ammonia Injector Cooling Water Supply Pump. It, together with the interface valve, piping system, and fuel injection system, constitutes the Ammonia Injector Cooling Water System. The main purpose of the Ammonia Injector Cooling Water System is to cool the ammonia injectors when the engine is running in diesel mode. When the engine is running in diesel mode, the ammonia injector cooling water circulates from the Ammonia Injector Cooling Water Surge Tank to the ammonia injectors and then returns to the Cooling Water Surge Tank in a closed loop. In addition, the injector cooling water is used during the purge process to remove vapors after the liquid purge.

[0057] The ejector cooling water system is a closed-loop water system with an independent electronic control system. During operation, the ejector cooling pump supplies cooling water to the engine according to the control instructions. During the process, the ejector cooling pump and bypass return flow are used to control the pressure according to the pressure requirements. The pressure replenishment and pressure relief procedures of the cooling water tank are automatically executed according to the set value. All remote control valves and pumps in the system can be selected in manual operation mode and manually operated separately in the control interface. LIT041 monitors the cooling water tank level. When the higher / lower liquid level alarm occurs, the system operation is automatically stopped; PIT041 monitors the cooling water tank pressure. When the higher / lower pressure alarm occurs, the system operation is automatically stopped. TIT041 monitors the cooling water tank temperature; TIT042 monitors the outlet temperature of the water cooler; PIT042 monitors the system outlet pressure; FS041 monitors the cooling water flow rate and automatically stops the system operation when the flow rate is lower than the alarm.

[0058] Ammonia residual liquid collection and treatment system: After fuel switching or emergency shutdown, nitrogen is used to purge the main engine, and the gas-liquid mixture refluxed from the main engine needs to be collected and treated. The designed ammonia fuel station residual liquid collection and treatment system mainly consists of a gas-liquid separation tank and an ammonia scrubbing unit. The gas-liquid separation tank collects the liquid ammonia purged from the main engine in the first stage, and nitrogen-seales it with high-pressure nitrogen to keep it in a liquid state, and outputs the liquid ammonia to the inlet of the high-pressure pump 105 for recycling when the liquid level is high.

[0059] The gas-liquid separation tank mainly controls the Q301 liquid ammonia output valve; Q302 nitrogen replenishment valve; Q303 ammonia discharge valve. The ammonia scrubbing unit is mainly composed of two scrubbing containers, three ammonia water pumps and two heat exchangers. When in operation, the ammonia-containing gas to be scrubbed enters, triggering the flow switch and activating the scrubbing unit operation. The gas-liquid separation tank has two actions: nitrogen pressure replenishment and discharge valve pressure relief. When the pressure exceeds the upper limit or is lower than the lower limit, the program is automatically executed according to the set value. The scrubbing area consists of a scrubbing container, an ammonia water pump and a heat exchanger. When the scrubbing unit is in operation, the spray tower sprays fresh water, and the fresh water flow is controlled by the control valve. The sensor measures and feeds back the actual flow. TIT501 monitors the temperature of the gas-liquid separation tank, and starts water spraying when the temperature is higher and alarms; PIT501 / 502 controls and detects the pressure of the gas-liquid separation tank respectively; LIT501 detects the liquid level of the gas-liquid separation tank, opens Q301 when the liquid level is higher, and closes Q301 when the liquid level is lower; LIT502 detects the liquid level of the washing cabinet, and reminds you to discharge ammonia water when the alarm is higher, and reminds you to add fresh water when the alarm is lower.

[0060] Introduction to PLC and host computer: According to the overall design scheme and control strategy of the ammonia fuel supply system, hardware design and software selection are carried out. TIA Portol software is used to design the PLC automatic control system, so the PLC uses the S7 series products of Siemens (SIEMENS). According to the number of input / output points, memory capacity, functions, etc., the corresponding S7-1500PLC is selected, and AI, AQ, DI, DQ and other signal input and output modules are added. The specific hardware configuration is shown in the attached figure. The PLC program mainly realizes communication control with HMI, control of various valves, components, and areas of the ammonia fuel supply system, and equipment fault alarm. WinCC software and desktop computers are used to control and monitor the overall supply system. The overall operating status of the supply system is fed back to the HMI interface in real time through variables. The operator can monitor the supply system status in real time through the HMI and can issue instructions to control the supply system. The supply system can monitor and record alarms in real time, and stop the system operation when necessary to facilitate the subsequent maintenance and overhaul of equipment. The specific HMI interface is shown in the attached figure. Due to the special physical and chemical properties of ammonia, the existing diesel, LNG, methanol and other supply systems cannot be used. In combination with national standards and classification society regulations, a supply system suitable for ammonia fuel has been developed to ensure the stable storage and safe transportation of ammonia fuel. Fully automatic control of the supply system has also been developed based on PLC and WinCC, including fuel filling, storage, transportation, supply and other links. The system can monitor in real time and automatically adjust the temperature, flow, pressure, etc. of the fuel according to the needs of the main engine to ensure the stability and efficiency of the ammonia fuel system.

[0061] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0062] The automatic control system for ammonia fuel supply provided by the present invention is introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An automatic control system for ammonia fuel supply, characterized in that: include: Unloading crane pipe, unloading compressor, liquid ammonia storage tank, low-pressure pump, high-pressure pump, first heat exchanger, duplex filter and controller; The unloading crane pipe is connected to the filling port of the liquid ammonia storage tank, and the unloading compressor is connected to the gas outlet of the liquid ammonia storage tank; The low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter are sequentially connected to the liquid ammonia outlet of the liquid ammonia storage tank through pipelines, and an outlet valve is provided at the liquid ammonia outlet of the liquid ammonia storage tank; The controller is used to control the working modes of the low-pressure pump, the high-pressure pump, the first heat exchanger and the duplex filter to adjust the pressure, temperature and purity of the output ammonia fuel to a target range.

2. The automatic control system for ammonia fuel supply according to claim 1, characterized in that: Also includes: Glycol expansion tanks, glycol pumps, heaters, coolers and chillers; The heater and the cooler are both connected to the first heat exchanger through the ethylene glycol pump, and the ethylene glycol expansion water tank is connected to the first heat exchanger; The chiller is in communication with the cooler.

3. The automatic control system for ammonia fuel supply according to claim 2, characterized in that: The ethylene glycol pump comprises: a first ethylene glycol pump and a second ethylene glycol pump; The input ends of the first ethylene glycol pump and the output ends of the second ethylene glycol pump are connected to each other, forming a first loop; The heater and the cooler are both in communication with the first heat exchanger through the first circuit.

4. The automatic control system for ammonia fuel supply according to claim 3, characterized in that: Also includes: a first pressure sensor disposed between the first circuit and the heater and the cooler; The controller is also used to receive the ethylene glycol outlet pressure collected by the first pressure sensor, and control the high-pressure pump, the low-pressure pump, the first ethylene glycol pump and the second ethylene glycol pump to stop working when the ethylene glycol outlet pressure is greater than a first target pressure threshold.

5. The automatic control system for ammonia fuel supply according to claim 1, characterized in that: A filling valve is provided on the pipeline between the unloading crane pipe and the liquid ammonia storage tank, and a gas phase pipe valve is provided on the pipeline between the unloading compressor and the gas outlet of the liquid ammonia storage tank; The controller is also used to control the opening of the filling valve and the gas phase pipe valve in the unloading mode.

6. The automatic control system for ammonia fuel supply according to claim 5, characterized in that: The low-pressure pump comprises: a first low-pressure pump and a second low-pressure pump, and the high-pressure pump comprises: a first high-pressure pump and a second high-pressure pump; the input ends of the first low-pressure pump and the second low-pressure pump are connected to each other and the output ends are connected to each other to form a second loop, and the input ends of the first high-pressure pump and the second high-pressure pump are connected to each other and the output ends are connected to each other to form a third loop; The second circuit, the third circuit, the first heat exchanger and the duplex filter are connected in sequence and then connected to the liquid ammonia outlet of the liquid ammonia storage tank; Furthermore, the output end of the second circuit is also connected to the input end of the first heat exchanger through a bypass return valve; The controller is also used to control the filling valve, the outlet valve and the bypass reflux valve to open after controlling the low-pressure pump to start, and to adjust the liquid ammonia flow by controlling the bypass reflux valve.

7. The automatic control system for ammonia fuel supply according to claim 1, characterized in that: The duplex filter comprises: a first duplex filter and a second duplex filter; The input ends of the first duplex filter and the second duplex filter are both connected to the output end of the first heat exchanger, and the output ends of the first duplex filter and the second duplex filter are provided with a second pressure sensor; The controller is further configured to receive the liquid ammonia pressure difference between the outputs of the first double filter and the second double filter collected by the second pressure sensor, and to issue a reminder to replace the double filter element when the liquid ammonia pressure difference is greater than a second target pressure threshold.

8. The automatic control system for ammonia fuel supply according to claim 1, characterized in that: Also includes: An ejector cooling water module is composed of a cooling water tank, a second heat exchanger and a cooling water pump which are connected in sequence, and is used to provide cooling water to the ammonia ejector.

9. The automatic control system for ammonia fuel supply according to claim 1, characterized in that: Also includes: Ammonia collection tank and first washing cabinet; The input end of the ammonia collection tank is connected to the liquid ammonia storage tank through a discharge valve, and the output end of the ammonia collection tank is connected to the first washing cabinet.

10. The automatic control system for ammonia fuel supply according to any one of claims 1 to 9, characterized in that: Also included: a gas-liquid separation tank and a second washing cabinet; The input end of the gas-liquid separation tank is communicated with the output end of the low-pressure pump, and the output end of the gas-liquid separation tank is communicated with the second washing cabinet.

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