Liquid ammonia heating device for engine, engine and liquid ammonia heating method

Abstract

The application relates to the technical field of ammonia fuel engines, in particular to a liquid ammonia heating device for an engine, an engine and a liquid ammonia heating method, so as to fully utilize energy. The device comprises a heat exchanger body, a first temperature sensor, an electric heater, a control module, a first heating pipeline and / or a second heating pipeline, a first control valve and / or a second control valve, a second temperature sensor and / or a third temperature sensor, the heat exchanger body is provided with a containing cavity containing liquid ammonia; the first temperature sensor detects the temperature of the liquid ammonia; the first heating pipeline is used for flowing of cooling liquid of the engine, the second heating pipeline is used for flowing of tail gas of the engine, and the cooling liquid and / or the tail gas heat the liquid ammonia; the first control valve controls the opening and closing of the first heating pipeline, and the second control valve controls the opening and closing of the second heating pipeline; the second temperature sensor detects the temperature of the cooling liquid, and the third temperature sensor detects the temperature of the tail gas; and the electric heater heats the liquid ammonia in the containing cavity.

Description

Technical Field

[0001] This application relates to the field of ammonia fuel engine technology, and in particular to a liquid ammonia heating device for an engine, an engine, and a liquid ammonia heating method. Background Technology

[0002] Ammonia, with the molecular formula NH3, contains no carbon atoms and is a good zero-carbon fuel. However, compared to fuels like diesel and gasoline, ammonia has a lower calorific value, meaning that the heat released per unit mass of ammonia is less than that of gasoline and diesel. To ensure that vehicles can carry more ammonia fuel, ammonia is generally stored in high-pressure tanks. The ammonia in the high-pressure tanks is liquid ammonia. To allow ammonia to mix better with air for combustion, the liquid ammonia needs to be vaporized, which requires endothermic heating. Existing methods for ammonia vaporization typically use electric heating to heat the liquid ammonia. Using electric heating throughout vehicle operation results in high energy consumption and is not conducive to fuel conservation. Summary of the Invention

[0003] This application discloses a liquid ammonia heating device, an engine, and a liquid ammonia heating method for engines to solve the problems of high energy consumption and potential insufficient ammonia supply in existing electric heating methods.

[0004] To achieve the above objectives, this application provides the following technical solution:

[0005] In a first aspect, this application provides a liquid ammonia heating device for an engine. The liquid ammonia heating device includes a heat exchanger body, a first temperature sensor, an electric heater, a control module, and a first heating pipe and / or a second heating pipe, a first control valve and / or a second control valve, a second temperature sensor and / or a third temperature sensor. The heat exchanger body is provided with a receiving cavity for containing liquid ammonia. The first temperature sensor is used to detect the temperature t of the liquid ammonia in the receiving cavity. The first heating pipe is used to supply coolant flow to the engine, and the second heating pipe is used to supply exhaust gas flow to the engine. Both the coolant and / or exhaust gas are used to heat the liquid ammonia in the receiving cavity. The liquid ammonia is heated to convert it into gaseous ammonia; a first control valve controls the opening and closing of a first heating pipe, and a second control valve controls the opening and closing of a second heating pipe; a second temperature sensor detects the temperature of the engine coolant, and a third temperature sensor detects the temperature of the engine exhaust gas; an electric heater heats the liquid ammonia in the heat exchanger body to convert it into gaseous ammonia; a control module is connected to the electric heater and the first temperature sensor; the control module is connected to the first control valve and / or the second control valve; and the control module is connected to the second temperature sensor and / or the third temperature sensor.

[0006] Furthermore, it also includes a liquid level sensor that is connected to the control module via a signal. The liquid level sensor is used to detect the actual liquid level h of the liquid ammonia in the containment cavity and transmit the actual liquid level h to the control module.

[0007] Furthermore, it also includes a storage unit for storing liquid ammonia, and the storage unit is connected to the containment cavity via a first pipeline; the first pipeline is equipped with a first valve, and the first valve is connected to the control module.

[0008] Furthermore, it also includes a liquid ammonia flow meter installed in the first pipeline, which is connected to the control module via signal.

[0009] Furthermore, it also includes a second pipeline for connecting the receiving cavity and the combustion chamber. The second pipeline is equipped with a second valve and an ammonia injection valve that are signal-connected to the control module. The second valve is located between the receiving cavity and the ammonia injection valve, and the ammonia injection valve is used to inject gaseous ammonia from the second pipeline into the combustion chamber.

[0010] Furthermore, it also includes a pressure sensor, which is located in the containment cavity or the second pipeline. The pressure sensor is located at the front end of the ammonia injection valve and is used to detect the pressure of gaseous ammonia in the containment cavity or the second pipeline.

[0011] Secondly, this application provides an engine that includes a combustion chamber and a liquid ammonia heating device as described in the first aspect.

[0012] Thirdly, this application provides a liquid ammonia heating method using the liquid ammonia heating device of the first aspect, the liquid ammonia heating method comprising the following steps: obtaining the temperature t of the liquid ammonia in the containment cavity of the heat exchanger body; obtaining the temperature T of the coolant in the first heating pipe. y And / or obtain the temperature T of the exhaust gas inside the second heating pipe. a When the temperature t of the liquid ammonia is less than or equal to the first preset temperature T1, the electric heater is started; when t is greater than the first preset temperature T1, the electric heater is turned off, where T1 > 0; when the temperature T of the coolant... y When the temperature of the liquid ammonia is greater than or equal to the second preset temperature T2, the first control valve is opened; when the temperature t of the liquid ammonia is greater than the third preset temperature T3, the first control valve is closed. Where 0 < T2, T... y ≤T3; when the temperature T of the engine exhaust gas a When the temperature is greater than or equal to the fourth preset temperature T4, the second control valve is opened, where T1 < T4.

[0013] Furthermore, it also includes the following steps: obtaining the actual liquid ammonia level h in the containment cavity of the heat exchanger body; opening the first valve when the actual liquid ammonia level h is less than or equal to the first preset height H1; and closing the first valve when the actual liquid ammonia level h is greater than the second preset height H2, wherein 0 < H1 < H2.

[0014] Furthermore, before opening the first valve, the following steps are included: calculating the required amount of liquid ammonia based on the target liquid ammonia level H in the containment chamber and the actual liquid ammonia level h.

[0015] The liquid ammonia heating device for engines provided in this application allows the control module to control the opening and closing of the electric heater, the first control valve, and the second control valve according to the temperature of the internal cavity of the heat exchanger body, the temperature of the coolant in the first heating pipe, and the temperature of the exhaust gas in the second heating pipe. This allows for the selection of one or more heating methods based on different temperatures, fully utilizing the heat from the engine's coolant and / or exhaust gas to heat the liquid ammonia, thereby effectively saving energy. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of a liquid ammonia heating device according to an embodiment of this application;

[0017] Figure 2 This is a flowchart of a liquid ammonia heating method according to an embodiment of this application;

[0018] Figure 3 This is a flowchart illustrating the determination process for the liquid ammonia heating method in Embodiment 1 of this application.

[0019] Reference numerals: 100-Liquid ammonia heating device; 110-First temperature sensor; 120-First heating pipe; 121-First control valve; 130-Second heating pipe; 131-Second control valve; 140-Electric heater; 160-Liquid level sensor; 200-Storage unit; 300-First pipeline; 310-First valve; 320-First rotary valve; 330-Liquid ammonia flow meter; 400-Combustion chamber; 500-Second pipeline; 510-Second valve; 520-Ammonia injection valve; 530-Second rotary valve; 540-Ammonia flow meter; 600-Inlet pipeline; 700-Pressure sensor;

[0020] 01-Receiving cavity. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] In existing ammonia-fired engines, ammonia is typically stored in liquid form in high-pressure tanks to ensure sufficient fuel supply. To facilitate better mixing and combustion of ammonia and air, the liquid ammonia needs to be vaporized, which requires heat absorption. Current methods for ammonia vaporization usually employ electric heating to heat the liquid ammonia. Using electric heating throughout vehicle operation results in high energy consumption and is not conducive to fuel economy.

[0023] In view of this, embodiments of this application provide a liquid ammonia heating device for an engine. Figure 1 This is a schematic diagram of the structure of a liquid ammonia heating device according to an embodiment of this application, with reference to... Figure 1 The liquid ammonia heating device 100 includes a heat exchanger body, a first temperature sensor 110, an electric heater 140, a control module, a first heating pipe 121 and / or a second heating pipe 130, a first control valve 121 and / or a second control valve 131, and a second temperature sensor and / or a third temperature sensor. The heat exchanger body has a receiving cavity 01 for containing liquid ammonia, and an inlet and an outlet communicating with the receiving cavity 01. The first temperature sensor 110 is used to detect the temperature t of the liquid ammonia in the receiving cavity 01. The first heating pipe 121 is used to supply coolant flow from the engine, and the second heating pipe 130 is used to supply exhaust gas flow from the engine. Both the coolant and / or exhaust gas can exchange heat with the liquid ammonia in the receiving cavity 01 to heat the liquid ammonia, thereby converting the liquid ammonia into gaseous ammonia, which can be discharged from the receiving cavity 01 through the outlet. The first control valve 121 is used to control the opening and closing of the first heating pipe 121, and the second control valve 131 is used to control the opening and closing of the second heating pipe 130. The second temperature sensor detects the temperature of the engine coolant, and the third temperature sensor detects the temperature of the engine exhaust gas. The electric heater 140 heats the liquid ammonia within the heat exchanger body, converting it into gaseous ammonia. The control module is connected to the electric heater 140 and the first temperature sensor 110; the control module is also connected to the first control valve 121 and / or the second control valve 131; and the control module is further connected to the second and / or third temperature sensors. Therefore, the control module can control the opening and closing of the electric heater 140, and the first control valve 121 and / or the second control valve 131, based on the temperature of the liquid ammonia in the containment chamber 01, the temperature of the coolant, and the temperature of the exhaust gas, selecting one or more heating methods to fully utilize energy. For example, in the initial stage of engine operation, the temperature of the coolant and the temperature of the exhaust gas are relatively low. The control module controls the electric heater 140 to turn on. When the temperature of the coolant and / or the temperature of the exhaust gas rise to the preset temperature, the first control valve 121 and / or the second control valve 131 are opened to allow the liquid ammonia in the containment chamber 01 to exchange heat with the coolant and / or the exhaust gas.

[0024] In some implementations, the liquid ammonia heating device 100 may include an electric heater 140 and a first heating pipe 121, but does not include a second heating pipe 130; in other implementations, the liquid ammonia heating device 100 may include an electric heater 140 and a second heating pipe 130, but does not include the first heating pipe 121; in still other implementations, the liquid ammonia heating device 100 may include an electric heater 140, a first heating pipe 121 and a second heating pipe 130.

[0025] This application does not limit the specific shape and structure of the first heating pipe 121 and the second heating pipe 130. Optionally, the receiving cavity 01 may contain one, two, or more first heating pipes 121; optionally, the receiving cavity 01 may contain one, two, or more second heating pipes 130. It is understood that the more first heating pipes 121 and second heating pipes 130 there are, the larger the heat exchange area, and the higher the heating efficiency of the liquid ammonia in the receiving cavity 01. The specific number is set according to actual needs.

[0026] Optionally, the electric heater 140 can be a heating belt, heating rod, heating tube, etc.

[0027] Reference Figure 1 The liquid ammonia heating device 100 also includes a liquid level sensor 160 connected to the control module. The liquid level sensor 160 is used to detect the actual liquid level h of the liquid ammonia in the containment cavity 01 and transmit the actual liquid level h to the control module so that the control module can control the amount of liquid ammonia injected into the containment cavity 01 according to the actual liquid level h, so as to avoid the liquid ammonia content in the containment cavity 01 being too low and the heat exchange efficiency being reduced.

[0028] Continue to refer to Figure 1 The liquid ammonia heating device 100 also includes a storage unit 200 for storing liquid ammonia. The storage unit 200 is connected to the inlet of the receiving cavity 01 via a first pipe 300. The first pipe 300 is equipped with a first valve 310, which is connected to a control module. The control module controls the opening and closing of the first valve 310 according to the actual liquid level h, thereby regulating the injection volume of liquid ammonia into the receiving cavity 01. For example, the storage unit 200 can be a high-pressure storage bottle.

[0029] In some embodiments of this application, the liquid ammonia heating device 100 further includes a first rotary valve 320 disposed in the first pipeline 300, the function of which is to prevent ammonia leakage.

[0030] In some embodiments of this application, the liquid ammonia heating device 100 further includes a liquid ammonia flow meter 330 disposed in the first pipeline 300. The liquid ammonia flow meter 330 is connected to the control module for signal connection, so that the control module can calculate the amount of liquid ammonia injected into the containment cavity 01.

[0031] Continue to refer to Figure 1 The liquid ammonia heating device 100 also includes a second pipeline 500, which connects the outlet of the receiving cavity 01 to the combustion chamber 400. The second pipeline 500 is equipped with a second valve 510 and an ammonia injection valve 520, both connected to the control module. The second valve 510 is located between the receiving cavity 01 and the ammonia injection valve 520, and the ammonia injection valve 520 injects gaseous ammonia from the second pipeline 500 into the combustion chamber 400. Optionally, the second pipeline 500 and the combustion chamber 400 can be connected via an intake pipeline 600, where gaseous ammonia and oxygen are mixed, and the mixture then enters the combustion chamber 400 for combustion.

[0032] Continue to refer to Figure 1 The liquid ammonia heating device 100 also includes a pressure sensor 700, which is located in the containment cavity 01 or the second pipeline 500. The pressure sensor 700 is located at the front end of the ammonia injection valve 520. The pressure sensor 700 is used to detect the pressure of gaseous ammonia in the containment cavity 01 or the second pipeline 500 to ensure that the pressure meets the requirements for ammonia injection.

[0033] In some embodiments of this application, the liquid ammonia heating device 100 further includes a second rotary valve 530 disposed in the second pipeline 500, the function of which is to prevent ammonia leakage.

[0034] In some embodiments of this application, the liquid ammonia heating device 100 further includes an ammonia flow meter 540 disposed in the second pipeline 500, which is used to detect the flow rate of ammonia in the second pipeline 500.

[0035] Based on the same technical concept, embodiments of this application also provide an engine, which includes a combustion chamber 400 and a liquid ammonia heating device 100 as described in various possible implementations of this application. The combustion chamber 400 and the receiving cavity 01 are connected via a second pipeline 500. The engine may be a diesel engine.

[0036] Because it includes the liquid ammonia heating device 100 in this application, the engine also has the advantage of making full use of engine waste heat to heat liquid ammonia and reducing the energy consumption of liquid ammonia vaporization.

[0037] Based on the same technical concept, this application also provides a liquid ammonia heating method using the liquid ammonia heating device in various possible implementations of this application. Figure 2 This is a flowchart of a liquid ammonia heating method according to an embodiment of this application, with reference to... Figure 2 The liquid ammonia heating method includes the following steps:

[0038] Obtain the temperature t of the liquid ammonia in the containment cavity 01 of the heat exchanger body;

[0039] Obtain the temperature T of the coolant inside the first heating pipe 121 y And / or obtain the temperature T of the exhaust gas inside the second heating pipe 130. a ;

[0040] When the temperature t of liquid ammonia is less than or equal to the first preset temperature T1, the electric heater 140 is started; when t is greater than the first preset temperature T1, the electric heater 140 is turned off, where T1 > 0.

[0041] When the temperature of the coolant T y When the temperature t of the liquid ammonia is greater than or equal to the second preset temperature T2, the first control valve 121 is opened; when the temperature t of the liquid ammonia is greater than the third preset temperature T3, the first control valve 121 is closed, where 0 < T2, T3 < T4. y ≤T3;

[0042] When the temperature of the engine exhaust gas T a When the temperature is greater than or equal to the fourth preset temperature T4, the second control valve 131 is opened, where T1 < T4.

[0043] The first preset temperature T1, the second preset temperature T2, the third preset temperature T3, and the fourth preset temperature T4 can be set according to actual needs. For example, the first preset temperature T1 can be any temperature value between 40-60℃.

[0044] For example, the second preset temperature T2 can be any temperature value between 60-80°C. For example, the fourth preset temperature T4 can be any temperature value between 80-120°C.

[0045] When the engine is first started, the temperature inside the containment chamber 01 is relatively low. When the temperature t of the liquid ammonia is less than or equal to the first preset temperature T1, for example, t≤5℃, the engine needs a large amount of ammonia for combustion. However, since the engine has just started, the engine coolant and exhaust gas temperatures are not very high, and the heating capacity is limited. Therefore, the electric heater is turned on to heat the liquid ammonia. When t is greater than the first preset temperature T1, the heating effect of the electric heater on the liquid ammonia decreases. At this time, the engine coolant temperature and exhaust gas temperature are already relatively high. In order to save energy, the electric heater 140 can be turned off to reduce energy consumption.

[0046] When the engine coolant and exhaust gas temperatures both reach the preset temperatures, the first heating pipe 121 and the second heating pipe 130 heat the liquid ammonia to ensure that the liquid ammonia heating device 100 can provide the ammonia required for engine combustion in the shortest possible time.

[0047] For example, the third preset temperature T3 can be T y+T0, where T0≥0. When the temperature t of the liquid ammonia is greater than the third preset temperature T3, the convective heat transfer capacity is reduced and the heating effect is not obvious because the temperature difference between the liquid ammonia in the containment cavity 01 and the coolant is small. At this time, the first control valve 121 is closed and the first heating pipe 121 stops exchanging heat with the liquid ammonia.

[0048] Specifically, when the temperature of the liquid ammonia in the containment cavity 01 exceeds the fifth preset temperature T5, for example, 60°C, the liquid ammonia heating device 100 can provide sufficient ammonia gas for engine combustion. At this time, the liquid ammonia heating device 100 can exchange heat with the liquid ammonia only through the exhaust gas in the second heating pipe 130, shutting off the other two heating methods, which can effectively save energy. Once the vehicle is towed and the engine exhaust gas temperature and volume are insufficient, causing the temperature of the liquid ammonia in the containment cavity 01 to drop below 60°C, the first control valve 121 is opened, and the coolant in the first heating pipe 121 exchanges heat with the liquid ammonia to maintain a stable internal temperature in the containment cavity 01.

[0049] Understandably, as liquid ammonia is consumed, the amount of liquid ammonia in the tank will decrease, the liquid ammonia level will drop, the heating area will decrease, and the ammonia production will be insufficient. At this time, the supply of ammonia will be greatly reduced, and the engine will experience a power reduction due to the decrease in the supply of ammonia. At this time, more heat is required for heating, and energy consumption will increase.

[0050] In view of this, the liquid ammonia heating method in the embodiments of this application further includes the following steps:

[0051] Obtain the actual liquid level h of liquid ammonia in the accommodating cavity 01 of the heat exchanger body;

[0052] When the actual liquid ammonia level h is less than or equal to the first preset height H1, the first valve 310 is opened;

[0053] When the actual liquid ammonia level h is greater than the second preset height H2, the first valve 310 is closed, where 0 < H1 < H2.

[0054] The first preset height H1 can be 5%-10% of the depth of the receiving cavity. The actual liquid ammonia level h in the receiving cavity cannot be lower than the first preset height H1 to ensure the robustness of the liquid ammonia heating device. The first valve is opened to allow liquid ammonia in the storage unit to be injected into the receiving cavity; the second valve and the ammonia injection valve are opened to ensure pressure balance in the receiving cavity, preventing excessive internal pressure from preventing the liquid ammonia from being injected smoothly, and preventing ammonia from escaping from the receiving cavity and polluting the air. The ammonia injection valve injects the ammonia from the receiving cavity into the air intake pipe or combustion chamber for combustion.

[0055] The second preset height H2 can be 90%-100% of the depth of the receiving cavity. The first valve is closed to stop the injection of liquid ammonia from the storage unit into the receiving cavity. As the liquid ammonia is consumed, when the actual liquid ammonia level h is less than or equal to the first preset height H1, the first valve is opened, and the above process is repeated.

[0056] The above-mentioned liquid ammonia heating method can make full use of the engine waste heat to heat the liquid ammonia, reduce the energy consumption of liquid ammonia vaporization, and ensure the supply of ammonia, avoiding the problem of insufficient ammonia supply, which is conducive to the promotion and application of ammonia fuel engines.

[0057] In some embodiments of this application, the following steps are included before opening the first valve:

[0058] The required amount of liquid ammonia, V, is calculated based on the target liquid ammonia level H in the containment chamber and the actual liquid ammonia level h.

[0059] The demand for liquid ammonia is V = (Hh) S, where H is the target liquid level of liquid ammonia and S is the bottom area of ​​the containment cavity.

[0060] In some embodiments of this application, after opening the first valve, the following steps are further included:

[0061] Obtain the flow rate Q of the liquid ammonia injected into the containment chamber;

[0062] The injection volume of liquid ammonia, W=Q, is calculated based on the flow rate Q and injection time T. T;

[0063] When the injection volume W of liquid ammonia equals the liquid ammonia demand V, the first valve is closed.

[0064] The liquid ammonia heating device and liquid ammonia heating method of this application will be further described in detail below with reference to the embodiments.

[0065] Example 1

[0066] This embodiment describes a liquid ammonia heating device and a diesel engine incorporating the liquid ammonia heating device, see reference. Figure 1The liquid ammonia heating device 100 includes a heat exchanger body, a first temperature sensor 110, an electric heater 140, a control module, a first heating pipe 121 and / or a second heating pipe 130, a first control valve 121 and / or a second control valve 131, a second temperature sensor and / or a third temperature sensor. The heat exchanger body is provided with a receiving cavity 01 for containing liquid ammonia. The first temperature sensor 110 is used to detect the temperature t of the liquid ammonia in the receiving cavity 01. The first heating pipe 121 is used to supply coolant flow from the engine, and the second heating pipe 130 is used to supply exhaust gas flow from the engine. Both the coolant and / or exhaust gas are used to heat the liquid ammonia in the receiving cavity 01. The system is designed to convert liquid ammonia into gaseous ammonia. A first control valve 121 controls the opening and closing of the first heating pipe 121, and a second control valve 131 controls the opening and closing of the second heating pipe 130. A second temperature sensor detects the temperature of the engine coolant, and a third temperature sensor detects the temperature of the engine exhaust. An electric heater 140 heats the liquid ammonia within the heat exchanger body to convert it into gaseous ammonia. The control module is connected to the electric heater 140 and the first temperature sensor 110. The control module is also connected to the first control valve 121 and / or the second control valve 131. Finally, the control module is connected to the second temperature sensor and / or the third temperature sensor.

[0067] Figure 3 The flowchart for the determination of the liquid ammonia heating method in Embodiment 1 of this application is shown below. Figure 3 The liquid ammonia heating method using the above-mentioned liquid ammonia heating device and diesel engine includes the following steps:

[0068] Diesel engine start;

[0069] Obtain the actual liquid level h of liquid ammonia in the containment cavity of the heat exchanger body;

[0070] If the actual liquid ammonia level h is greater than the first preset height H1, then start heating the liquid ammonia in the containment chamber and close the first valve; otherwise, calculate the required amount of liquid ammonia V = (Hh). S, open the first valve;

[0071] If the actual liquid ammonia level h is greater than the second preset height H2, the first valve is closed, where 0 < H1 < H2;

[0072] Determine if the temperature t of the liquid ammonia is less than or equal to 40℃. If so, activate the enhanced heating mode, including starting the electric heater. If the temperature t of the liquid ammonia is greater than 40℃, turn off the electric heater. Determine the temperature T of the coolant. y If the temperature is greater than or equal to 60℃, open the first control valve; otherwise, close the first control valve. If the temperature of the engine exhaust is greater than or equal to 100℃, open the second control valve; otherwise, close the second control valve.

[0073] Determine if the temperature t of the liquid ammonia is between 40-60℃. If so, activate the secondary heating mode, in which the electric heater is turned off. Determine the temperature T of the coolant. y If the temperature is greater than or equal to 60℃, open the first control valve; otherwise, close the first control valve. If the temperature of the engine exhaust is greater than or equal to 100℃, open the second control valve; otherwise, close the second control valve.

[0074] If the temperature t of the liquid ammonia is greater than or equal to 60℃, the heat preservation and heating mode is activated, in which the electric heater and the first control valve are turned off; if the temperature of the engine exhaust gas is greater than or equal to 100℃, the second control valve is activated; otherwise, the second control valve is turned off.

[0075] The liquid ammonia heating device and method, and the diesel engine in Example 1 have the following advantages:

[0076] 1. It can simultaneously use electric heating, diesel engine coolant heating and exhaust gas heating. Compared with the commonly used electric heating method, it can fully collect the waste heat of diesel engine to heat liquid ammonia, which greatly reduces the energy consumption of liquid ammonia vaporization. At the same time, different heating methods are set according to different temperature conditions in the heat exchanger body, which can fully guarantee the supply of ammonia and avoid the problem of insufficient ammonia supply.

[0077] 2. The liquid ammonia level in the containment chamber can be determined by the liquid level sensor, and the opening and closing of the first valve can be adjusted to ensure that there is enough liquid ammonia in the containment chamber, thereby ensuring the efficiency of heat exchange.

[0078] 3. When the electric heater, the first heating pipe, and the second heating pipe are used simultaneously, the heating efficiency is high and a sufficient amount of ammonia can be provided in a short time.

[0079] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this application without departing from the spirit and scope of this application. Therefore, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application also intends to include these modifications and variations.

Claims

1. A liquid ammonia heating device for an engine, characterized in that, include: The heat exchanger body is provided with a receiving cavity for containing liquid ammonia; A first temperature sensor is used to detect the temperature t of the liquid ammonia inside the containment cavity; A first heating pipe and a second heating pipe, the first heating pipe being used to supply coolant to the engine, and the second heating pipe being used to supply exhaust gas to the engine, both the coolant and the exhaust gas being used to heat the liquid ammonia in the containment cavity, so that the liquid ammonia is converted into gaseous ammonia; A first control valve and a second control valve, wherein the first control valve is used to control the opening and closing of the first heating pipe, and the second control valve is used to control the opening and closing of the second heating pipe. A second temperature sensor and a third temperature sensor, the second temperature sensor being used to detect the temperature of the engine coolant, and the third temperature sensor being used to detect the temperature of the engine exhaust gas; An electric heater is used to heat the liquid ammonia in the containment cavity to convert the liquid ammonia into gaseous ammonia. The control module is connected to the electric heater and the first temperature sensor; the control module is connected to the first control valve and the second control valve; and the control module is connected to the second temperature sensor and the third temperature sensor. The control module is configured as follows: The temperature t of the liquid ammonia inside the containment cavity of the heat exchanger body is obtained; Obtain the temperature T of the coolant in the first heating pipe. y and obtain the temperature T of the exhaust gas inside the second heating pipe a ; When the temperature t of the liquid ammonia is less than or equal to the first preset temperature T1, the enhanced heating mode is activated and the electric heater is started; when t is greater than the first preset temperature T1, the electric heater is turned off, wherein T1 > 0. Determine whether the temperature t of the liquid ammonia is between a first preset temperature T1 and a second preset temperature T2. If the temperature t of the liquid ammonia is between the first preset temperature T1 and the second preset temperature T2, activate the secondary heating mode; when the temperature T of the coolant... y When the temperature t of the liquid ammonia is greater than or equal to the second preset temperature T2, the first control valve is opened; when the temperature t of the liquid ammonia is greater than the third preset temperature T3, the first control valve is closed, where 0 < T2, T3 < T4. y ≤T3; when the temperature T of the engine exhaust gas a When the temperature is greater than or equal to the fourth preset temperature T4, the second control valve is opened, where T1 < T4; If the temperature t of the liquid ammonia is not between the first preset temperature T1 and the second preset temperature T2, determine whether the temperature t of the liquid ammonia is greater than or equal to the second preset temperature T2; if the temperature t of the liquid ammonia is greater than or equal to the second preset temperature T2, activate the heat preservation and heating mode, turn off the electric heater, and close the first control valve; when the temperature T of the engine exhaust gas... a When the temperature is greater than or equal to the fourth preset temperature T4, the second control valve is opened, where T1 < T4; Based on the acquired real-time temperature parameters, the system dynamically switches between enhanced heating mode, secondary heating mode, and heat preservation heating mode.

2. The liquid ammonia heating device according to claim 1, characterized in that, It also includes a liquid level sensor that is signal-connected to the control module. The liquid level sensor is used to detect the actual liquid level h of the liquid ammonia in the containment cavity and transmit the actual liquid level h to the control module.

3. The liquid ammonia heating device according to claim 1, characterized in that, It also includes a storage unit for storing the liquid ammonia, and the storage unit is connected to the receiving cavity via a first pipeline; The first pipeline is equipped with a first valve, which is connected to the control module.

4. The liquid ammonia heating device according to claim 3, characterized in that, It also includes a liquid ammonia flow meter installed in the first pipeline, and the liquid ammonia flow meter is signal-connected to the control module.

5. The liquid ammonia heating device according to claim 4, characterized in that, It also includes a second pipeline for connecting the receiving cavity and the combustion chamber. The second pipeline is equipped with a second valve and an ammonia injection valve that are signal-connected to the control module. The second valve is located between the receiving cavity and the ammonia injection valve. The ammonia injection valve is used to inject gaseous ammonia from the second pipeline into the combustion chamber.

6. The liquid ammonia heating device according to claim 5, characterized in that, It also includes a pressure sensor, which is disposed in the receiving cavity or the second pipeline. The pressure sensor is located at the front end of the ammonia injection valve and is used to detect the pressure of gaseous ammonia in the receiving cavity or the second pipeline.

7. An engine, characterized in that, It includes a combustion chamber and a liquid ammonia heating device as described in any one of claims 1-6.

8. A method for heating liquid ammonia, characterized in that, Applied to the liquid ammonia heating device as described in any one of claims 3-6.

9. The liquid ammonia heating method according to claim 8, characterized in that, It also includes the following steps: Obtain the actual liquid level h of the liquid ammonia in the containment cavity of the heat exchanger body; When the actual liquid level h of the liquid ammonia is less than or equal to the first preset height H1, the first valve is opened; When the actual liquid level h of the liquid ammonia is greater than the second preset height H2, the first valve is closed, where 0 < H1 < H2.

10. The liquid ammonia heating method according to claim 9, characterized in that, Before opening the first valve, the following steps are also included: calculating the required amount of liquid ammonia based on the target liquid ammonia level H in the containment cavity and the actual liquid ammonia level h.

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