Systems and processes for pilot fuel synthesis using engine waste heat

Abstract

A system for an internal combustion engine (100) is described here. The system uses a reactor (120) to generate pilot fuel (112) from the primary fuel (104) to aid ignition of the primary fuel (104). The system uses one or more heating devices to raise the temperature of the primary fuel (104) to the operating temperature of a reactor (120), which is used to convert the primary fuel (104) in a dehydration reaction. The heating devices utilize waste heat generated by the operation of the engine (102). This waste heat can be, for example, from a lubricant used to dissipate heat from the engine (102) components, as well as heat from the engine (102) exhaust gas. A control unit (146) is used to maintain an operational range of the pilot fuel (112) level in an accumulator (114).The accumulator (114) serves as a buffer to enable the engine (102) to continue receiving the pilot fuel (112) during dynamic and changing conditions of the engine (102).

Description

Technical field

[0001] The present disclosure relates generally to the operation of a propulsion machine and in particular to the use of a type of primary fuel for the synthesis of a pilot fuel using waste heat generated by the operation of an internal combustion engine. State of the art

[0002] Drive motors for working machines, such as internal combustion engines, fuel cells, batteries, and the like, are widely used in various industries. For example, internal combustion engines can be powered by a variety of different liquid fuels, gaseous fuels, and various mixtures. Spark-ignition engines use an electric spark to initiate the combustion of fuel and air, while in compression-ignition engines, the gases in a cylinder are typically compressed to a self-ignition threshold, so that the fuel ignites without the need for a spark. Furthermore, in pilot-ignition applications, including dual-fuel applications, a mixture of a gaseous fuel, such as natural gas, and air is introduced into a cylinder, and ignition is initiated by a relatively small direct injection of a compression-ignition fuel (e.g., gasoline).Pilot fuel) is triggered, which ignites itself to initiate the ignition of the relatively larger main charge.

[0003] As part of efforts to improve the efficiency of these engines, researchers have explored various types of alternative fuel blends, including alcoholic fuels such as methanol and ethanol, as well as other chemicals like formaldehyde. In some examples, methanol is injected directly into an engine cylinder and ignited with a pilot fuel or a spark. The use of methanol can offer several advantages over other alternative fuels. For example, methanol has relatively low production costs and can be manufactured more cost-effectively than other alternative fuels. Furthermore, the availability of methanol can be greater than that of other alternative fuel sources because methanol can be produced in a variety of ways from materials ranging from natural gas to coal.Additionally, methanol is relatively safe to use, store, and transport because it has a comparatively low flammability risk. As mentioned above, a pilot fuel may be required to aid the ignition of the methanol. For methanol-powered engines, diesel fuel is often used as the pilot fuel to ignite the low-cetane methanol fuel. Typically, the diesel fuel, acting as the pilot fuel, is injected into a combustion chamber prior to the injection of the methanol fuel. The ignition of the diesel fuel (or pilot fuel) then ignites the methanol fuel.

[0004] In some cases, diesel fuel may not be desirable or available. Therefore, some efforts have been made to provide a pilot fuel for use in an internal combustion engine that uses other types or sources of pilot fuel. For example, European Patent Application No. 419743A1 to Galvin (“the '743 application”) describes a system set up to produce dimethyl ether (DME) using methanol stored in a storage tank. The '743 application system uses a dehydrogenation reactor to convert the methanol into DME. However, the system described in the '743 application may be limited in its use because the system does not provide for the storage or use of excess DME production. Furthermore, in some cases where methanol is used as the primary fuel, it may be necessary to purge the methanol from the system before shutdown.The system described in the 743 application would be limited in situations where methanol purging is required. Additionally, the pilot fuel produced by the system described in the 743 application might not be available during system startup until the DME production unit has reached its operating temperature after the engine has been started and run for some time. As a result of the aforementioned shortcomings and other unspecified deficiencies, the system described in the 743 application could be limited in its use due to the inability to store excess DME, provide DME prior to startup, or meet safety requirements when the methanol and / or DME must be purged before shutdown.

[0005] Examples in the present disclosure aim to overcome shortcomings of such systems. Brief description

[0006] In one aspect of the subject matter disclosed herein, a system comprises an internal combustion engine that consumes a primary fuel and a pilot fuel, a primary fuel tank that supplies the primary fuel to a primary fuel distributor for use by the internal combustion engine, a pilot fuel system configured to produce the pilot fuel from the primary fuel, wherein the pilot fuel system comprises a pilot fuel pump fluidically connected to the primary fuel tank, the pilot fuel pump being configured to pump the primary fuel from the primary fuel tank to a reactor of the pilot fuel system, the reactor receiving the primary fuel from the pilot fuel pump, the reactor being configured to convert the primary fuel received by the pilot fuel pump from an alcohol to an ether, and wherein a product of the reactor is the pilot fuel,comprising unreacted primary fuel and water, a condenser that receives the reactor product, the condenser being configured to condense the unreacted primary fuel and water in the product received by the reactor into liquefied unreacted primary fuel and water, a separator that receives the liquefied unreacted primary fuel and water and the pilot fuel, the separator being configured to separate the pilot fuel from the liquefied unreacted primary fuel and water, a waste pump that receives the liquefied unreacted primary fuel and water from the separator, the waste pump being configured to pump the liquefied unreacted primary fuel and water to the primary fuel distributor, and a product pump that receives the pilot fuel from the separator, the product pump being configured topumping the pilot fuel converted from the primary fuel to an accumulator for use by the internal combustion engine, a heating device that receives the primary fuel, wherein the heating device is configured to heat the primary fuel pumped into the pilot fuel system to an operating temperature of the reactor using engine waste heat, and a control system to maintain a level of the pilot fuel stored in the accumulator within an operating range.

[0007] In an additional aspect of the subject matter now disclosed, a method for operating an internal combustion engine comprises directing a primary fuel from a primary fuel tank into a first heating device of a pilot fuel system, exchanging heat between the primary fuel in the first heating device and a first fluid from the engine to raise the temperature of the primary fuel from an initial temperature to a first temperature, directing the primary fuel at the first temperature into a second heating device, exchanging heat between the primary fuel in the second heating device and a second fluid from the engine to raise the temperature of the primary fuel in the second heating device from the first temperature to a second temperature.Directing the primary fuel from the second heating device into a reactor and converting the primary fuel in the reactor into a pilot fuel through a dehydration reaction in the reactor.

[0008] In another aspect of the presently disclosed subject matter, a pilot fuel system configured to produce a pilot fuel from a primary fuel comprises a pilot fuel pump fluidically connected to the primary fuel tank, the pilot fuel pump being configured to pump the primary fuel from the primary fuel tank; a first heating device fluidically connected to the pilot fuel pump to receive the primary fuel from the pilot fuel pump, the first heating device being configured to exchange heat between the primary fuel and a first fluid from an engine in order to raise the temperature of the primary fuel from an initial temperature to a first temperature; and a second heating device fluidically connected to the first heating device to receive the primary fuel from the first heating device.wherein the second heating device is configured to exchange heat between the primary fuel and a second fluid from the engine in order to raise the temperature of the primary fuel from the first temperature to a second temperature, a reactor fluidically connected to the second heating device to receive the primary fuel from the second heating device, the reactor being configured to convert the primary fuel received from the second heating device from an alcohol to an ether, a product of the reactor comprising the pilot fuel, unreacted primary fuel and water, a condenser receiving the product of the reactor, the condenser being configured to condense the unreacted primary fuel and water in the product received from the reactor to liquefied unreacted primary fuel and water, a separator separating the liquefied,a separator that receives unreacted primary fuel and water, as well as pilot fuel, wherein the separator is configured to separate the pilot fuel from the liquefied unreacted primary fuel and water; a waste pump that receives the liquefied unreacted primary fuel and water from the separator, wherein the waste pump is configured to pump the liquefied unreacted primary fuel and water into the primary fuel distributor; a product pump that receives the primary fuel from the separator, wherein the product pump is configured to pump the primary fuel converted from the primary fuel into an accumulator for use by an internal combustion engine; and a control system to maintain a level of primary fuel stored in the accumulator within an operating range, wherein the control system is configured toto change the speed of the primary fuel pump in order to change the production speed of the primary fuel. Brief description of the drawings Fig. Figure 1 is a schematic representation of a system, including an internal combustion engine, which, according to one or more examples of the present disclosure, produces a primary fuel from a primary fuel, which uses heating devices to heat a primary fuel to an operating temperature of a reactor used for converting the primary fuel into the pilot fuel. Fig. Figure 2 is a schematic representation of a system, including an internal combustion engine, which, according to one or more examples of the present disclosure, uses a heating device for heating a primary fuel to an operating temperature of a reactor used for converting the primary fuel into the pilot fuel. Fig. Figure 3 illustrates a method for operating an internal combustion engine, wherein a control system according to various examples of the subject matter disclosed herein maintains a level of pilot fuel in an accumulator. Fig. Figure 4 shows a component-level view of a controller for use with the systems and methods described herein according to various examples of the present disclosed subject matter. Detailed description

[0009] Wherever possible, the same reference numerals are used in the drawings to designate identical or similar parts. With reference to Fig. Figure 1 shows an internal combustion engine system 100 which, according to one or more examples of the present disclosure, produces a pilot fuel using a primary fuel as the source of the pilot fuel. The system 100 comprises an engine 102. As used herein, the engine 102 is a type of propulsion machine which can be used separately from or in conjunction with other systems such as batteries, fuel cells, and the like. The engine 102 is an internal combustion engine which is operated with a primary fuel 104 which is stored in a primary fuel tank 106. The primary fuel 104 may, for example, comprise an alcoholic fuel such as methanol or ethanol, or other types of fuel (e.g., diesel fuel, gasoline, liquefied natural gas, etc.). For the purpose of illustrating an example of the subject matter disclosed herein, the primary fuel 104 is methanol.The primary fuel 104 is pumped by a primary fuel pump 108 into a primary fuel distributor 110 for use by the engine 102. As used herein, a “distributor” is a fuel line that supplies fuel to the injectors (not shown) of the engine 102. It should be noted that the subject matter disclosed herein is not limited to the use of fuel distributors.

[0010] In some examples, primary fuel 104 is a type of fuel with a comparatively lower cetane / higher octane rating, which, in the Fig. Figure 1 illustrates a configuration that uses a pilot fuel, such as pilot fuel 112, stored in an accumulator 114 and supplied via a pilot fuel distributor 116, to ignite the primary fuel 104. The pilot fuel 112 may be a liquid fuel with a higher cetane number / lower octane number, and the primary fuel 104 may be a liquid fuel with a lower cetane number / higher octane number. The terms "higher" and "lower" in this context can be understood as relative terms. Thus, the pilot fuel 112 may have a higher cetane number and a lower octane number than the cetane number and octane number of the primary fuel 104.

[0011] In the system 100 of Fig. 1. Pilot fuel 112 is produced from primary fuel 104 using pilot fuel system 118. Thus, while primary fuel tank 106 stores primary fuel 104 for use by engine 102, primary fuel tank 106 also stores the fuel for producing pilot fuel 112, which is then used by engine 102. To produce pilot fuel 112 in the example of Fig. To generate 1, the primary fuel 104 is subjected to a dehydration reaction in reactor 120 according to the following chemical reaction (1): 2CH3OH <--> CH3OCH3 + H2O; (1) where 2CH3OH represents methanol, CH3OCH3 represents dimethyl ether (DME), and H2O represents water. Reactor 120, a methanol dehydration reactor, can be a various type of reactor, equipped with different types of catalysts, capable of dehydrating methanol to DME. Some catalysts include aluminum oxide, zeolite, titanium oxide, and barium oxide. The reaction temperature within Reactor 120 can vary depending on the flow rate and the catalyst used, ranging from 200 °C to 400 °C. Since the dehydration reaction described above is an exothermic equilibrium reaction, it follows that, from a thermodynamic perspective, high conversion rates are achieved at the lowest possible reaction temperatures.From a reaction kinetic point of view, however, a minimum temperature is usually required to ensure sufficient speeds and thus acceptable DME conversion rates.

[0012] Heat exchangers 123A and 123B can be used to raise the temperature of the incoming primary fuel 104 to a desired temperature. In some examples, heat exchangers 123A and 123B can be used to preheat the incoming primary fuel 104. Heat exchanger 123A can be used to raise the temperature of the primary fuel 104 to a first temperature within a first temperature range. In some examples, the first temperature may be in a first temperature range of 70 °C to 90 °C, and in some examples in a first temperature range of 78 °C to 82 °C, although other temperature ranges may also be used, depending on the type of fuel in the incoming primary fuel 104.In some examples, the heat exchanger 123B can be used to raise the temperature of the fuel 104 from the first temperature to a second temperature within a second temperature range. In some examples, the second temperature can be a temperature within a second temperature range of 250 °C to 350 °C, and in some examples a second temperature range of 290 °C to 310 °C, although other temperature ranges can also be used, depending on the type of fuel of the incoming primary fuel 104. It should be noted that more than two or fewer than two heat exchangers can be used and fall within the scope of the subject matter currently disclosed, one example of which is shown in [reference]. Fig. 2 is shown. With returning reference to Fig. 1. The heat exchanger 123A and / or the heat exchanger 123B can be various types of heat exchangers, including but not limited to a double-tube heat exchanger, a shell and tube heat exchanger, and / or a plate heat exchanger. The flow pattern within the heat exchanger 123A and / or the heat exchanger 123B can be, among others, counterflow, crossflow, or coflow.

[0013] As mentioned above, the heat exchangers 123A and / or 123B utilize the heat generated by the operation of the engine 102 to provide energy for increasing the temperature of the primary fuel 104. In the Fig. In the example shown, the heat exchanger 123A uses a first heat source, the coolant 162. The coolant 162 is a coolant designed to dissipate heat from various components (not shown) of the engine 102. The coolant 162 can be lubricating oil or another form of engine fluid. As used herein, "engine fluid" includes any fluid that directly or indirectly absorbs heat from the engine 102. The coolant 162 can be used directly with the heat exchanger 123A (as in Fig. (1 shown) or for heating a secondary fluid for use with the heat exchanger 123A. As shown in Fig. As shown in Figure 1, a coolant pump 164 pumps the coolant 162 into the heat exchanger 123A. The control unit 146 controls the operation of the coolant pump 164. The coolant 162 enters the heat exchanger 123A at the inlet 166 and exits the heat exchanger 123A at the outlet 168. The heat from the coolant 162 entering the heat exchanger 123A is used to heat the fuel 104, which exits the heat exchanger 123A at the heater outlet 170. The heat from the coolant 162 is used to raise the temperature of the primary fuel 104 entering the heat exchanger 123A from an initial temperature to a first temperature within a first temperature range of 70 °C to 90 °C, and in some examples to a first temperature range of 78 °C to 82 °C. The volume flow of the coolant 162 can be controlled by regulating the speed of the coolant pump 164, which can be controlled by a control unit.An example control system is described in more detail below.

[0014] The heat exchanger 123B uses a second heat source, engine exhaust 172. The engine exhaust 172 is exhaust gas from the engine 102, produced as a product of combustion within the engine. The engine exhaust 172 can be received by various exhaust systems used for the engine 102. For example, the engine exhaust can be used before or after a turbocharger or an exhaust gas recirculation (EGR) system. The engine exhaust 172 is directed into an inlet 174 of the heat exchanger 123B and exits the heat exchanger 123B through the outlet 176. The engine exhaust 172 exiting the heat exchanger 123B can be directed to various emission control systems (not shown) or discharged into the environment (as in Fig. (1 shown). The heat from the engine exhaust 172 entering the heat exchanger 123B is used to heat the fuel 104, which exits the heat exchanger 123A at the heater outlet 170 and enters the heat exchanger 123B at the inlet 178, from its first temperature to a second temperature within a temperature range of 250°C to 350°C, and in some examples, within a second temperature range of 290°C to 310°C. The volume flow of the engine exhaust 172 can be controlled by a throttle valve 180, which can be regulated by a controller. An exemplary controller is described in more detail below. In some examples, a heat recovery system can be used to preheat the primary fuel 104 before it enters the heat exchanger 123A.To increase the temperature of the primary fuel 104, a pilot fuel pump 122 pumps a portion of the primary fuel 104 from the primary fuel tank 106 into the pilot fuel system 118. The pilot fuel pump 122 pumps the primary fuel 104 through a recuperator 124, the use of which is explained in more detail below. The primary fuel 104 exits the recuperator 124 and flows into the heat exchanger 123A. The primary fuel 104 exiting the heat exchanger 123B is reacted in the reactor 120 to form the pilot fuel 112, in this example DME. The output of reactor 120 comprises the pilot fuel 112, the water, and the unreacted primary fuel 104. The output of reactor 120 flows through the recuperator 124. As mentioned above, the pilot fuel system 118 uses a recuperator 124.The recuperator 124 is a heat exchanger that facilitates the exchange of heat between the comparatively higher-temperature products 121 from the reactor 120 and the comparatively lower-temperature primary fuel 104. As the temperature of the primary fuel 104 is increased, the temperature of the products 121 is decreased. The products 121, which comprise DME, water, and unreacted methanol, exit the recuperator 124 and enter a pressure regulator 126. The pressure regulator 126 reduces the pressure of the products 121 to liquefy at least some of the methanol and water present. Liquefaction of the methanol and water aids in the separation of methanol and water from the DME, thereby increasing the purity of the pilot fuel 112. The products 121 then enter the condenser 128 to further reduce their temperature (and in some examples, their pressure).The condenser 128 can be various types of heat exchangers for lowering the temperature of the products 121, including, among others, a shell-and-tube heat exchanger, a tube-in-tube heat exchanger, a direct or indirect heat exchanger, or a phase-change heat exchanger. It should be noted that in some examples, the methanol and water are liquefied primarily or exclusively in the condenser 128. Therefore, in these examples, the pressure regulator 126 cannot be used or installed.

[0015] After condenser 128, the products 121 are mainly methanol and water in liquid form and DME in gaseous form. The products 121 leave condenser 128 and enter separator 130. Separator 130 has a volume that allows gaseous DME (such as pilot fuel 112) to collect in the upper part of the volume, while the liquefied methanol and water occupy the lower part of separator 130. The gaseous DME 132 is pumped into accumulator 114 using product pump 134, the operation of which is controlled by controller 146. Product pump 134 increases the pressure of the DME to condense the gaseous DME into liquid DME for storage within accumulator 114. In some examples, the liquid methanol / water stream 136 can be considered a waste product.However, in order to reuse the unreacted methanol in the methanol / water stream 136, the methanol / water stream 136 is pumped through a mixer 140 into the primary fuel distributor 110 using the waste pump 138. The mixer 140 provides the introduction of the methanol / water stream 136 into the primary fuel 104, which is pumped into the primary fuel distributor 110 by the primary fuel pump 108.

[0016] During operation, the accumulator 114 acts as a buffer or "refill" tank, ensuring a consistent flow of pilot fuel 112 into the pilot fuel distributor 116. For example, the power demand of engine 102 may suddenly increase, requiring additional primary fuel 104 and pilot fuel 112 to meet the increased demand. Similarly, the power demand of engine 102 may suddenly decrease, requiring less primary fuel 104 and pilot fuel 112 to meet the reduced demand. However, the pilot fuel system 118 may not be able to instantly or rapidly increase or decrease the production of pilot fuel 112.To maintain the desired ratio between primary fuel 104 and pilot fuel 112 at higher or lower power levels, additional pilot fuel 112 can be drawn from the accumulator 114. During this power demand cycle, the pilot fuel system 118 increases or decreases production, as shown below. Fig. 3 described in more detail.

[0017] The pilot fuel 112 in the accumulator 114 may also be required during the start-up phase of the engine 102. During the start-up of the engine 102, the temperature of the pilot fuel system 118 may be reduced, making the conversion efficiency within the reactor 120 insufficient to produce the pilot fuel 112. Thus, as in the situation where an immediate increase in the power required by the engine 102 is achieved using the pilot fuel 112 in the accumulator 114, the pilot fuel 112 stored in the accumulator 114 before the engine 102 is shut down can be used while the temperature of the pilot fuel system 118 rises to the desired operating temperature. Furthermore, the pilot fuel 112 in the accumulator 114 can be used during the shutdown of the engine 102. In some examples, it may be necessary to completely evacuate the primary fuel 104 from the engine 102 before shutting it down.In some examples, pilot fuel 112 can be used instead of primary fuel 104 during shutdown, so that no primary fuel 104 remains after complete shutdown. The evacuation process can be assisted by the use of high-pressure nitrogen or inert gas (not shown).

[0018] Thus, the level of pilot fuel 112 in the accumulator 114 can be used to enable, but are not limited to, temporary events such as increasing or decreasing the power of the engine 102, starting the engine 102, and / or shutting down the engine 102. The level of pilot fuel 112 in the accumulator depends on the amount of pilot fuel 112 used by the engine 102 and the production rate of the pilot fuel 112 by the pilot fuel system 118. If the production rate of the pilot fuel 112 by the pilot fuel system 118 is greater than the consumption of the pilot fuel 112 by the engine 102, the level 142 of the pilot fuel 112 in the accumulator 114, which is detected by a level detector 144, increases.Similarly, if the production rate of the pilot fuel 112 by the pilot fuel system 118 is lower than the consumption of the pilot fuel 112 by the engine 102, the level 142 of the pilot fuel 112 in the accumulator 114, which is detected by the level detector 144, decreases. The control unit 146 is used to maintain the level 142 of the pilot fuel 112 in the accumulator 114 at a desired level (or within an operational range) and to control the heating of the primary fuel 104 by the heat exchangers 123A and 123B. It should be noted that the control unit 146 is configured to control various pumps and valves.

[0019] The control unit 146 has the task of maintaining the level 142 of the pilot fuel 112 in the accumulator above a certain level or within an operational range. For example, and not as a limitation, a minimum level 142 may be sufficient to provide at least enough pilot fuel 112 to ensure a complete shutdown and restart of the engine 102. As mentioned above, during a shutdown, the pilot fuel 112 may be used to assist in the removal of the primary fuel 104 from the engine 102 prior to shutdown. Furthermore, as mentioned above, the pilot fuel 112 may be used to provide a source of pilot fuel 112 during a start-up, allowing the pilot fuel system 118 sufficient time to reach a desired operational temperature to begin producing the pilot fuel 112.The minimum fill level 142 can also be determined by a predetermined quantity of pilot fuel 112, which is used when the power demand increases to a specific power rise or speed (e.g., in the case of an immediate or relatively rapid increase in power demand). The predetermined quantity can be based on a calculation of the volume of pilot fuel 112 required during an increased demand until the pilot fuel system 118 increases the production of pilot fuel 112 to meet the demand and also increases the fill level 142 of the pilot fuel 112 to compensate for the additional pilot fuel 112 used due to the increased power demand.

[0020] Therefore, a pump controller 148 of the controller 146 instructs the pilot fuel pump 122 to increase its flow rate when the controller 146 receives an input from the level detector 144 indicating that the level 142 is at or below a low setpoint level in the accumulator 114. The increased flow rate of the pilot fuel pump 122 increases the production of the pilot fuel 112. The controller 146 can determine a rate of change of the level 142, and detecting a rate of change above a setpoint for a high rate of change causes the pump controller 148 of the controller 146 to increase the flow rate (or velocity) of the pilot fuel pump 122 to a specific flow rate or to increase the flow rate at a specific velocity (i.e., to increase the velocity rapidly), based on the rate of change of the level 142.The increased flow rate of the pilot fuel pump 122 is designed to maintain at least a minimum level 142 in the accumulator 114. Similarly, the pump controller 148 of the control unit 146 instructs the pilot fuel pump 122 to decrease its flow rate when the control unit 146 receives an input from the level detector 144 indicating that the level 142 is at or above a high setpoint. The reduced flow rate of the pilot fuel pump 122 decreases the production of the pilot fuel 112. The control unit 146 can determine a rate of change of the level 142, with a higher rate of change causing the pump controller 148 of the control unit 146 to reduce the flow rate (or velocity) of the pilot fuel pump 122 to a specific flow rate or to decrease the flow rate at a specific velocity (i.e.,(to reduce speed quickly).

[0021] In some configurations, the control unit 146 can utilize the increased power demand of the engine 102 to anticipate changes in the use of the pilot fuel 112. In these examples, the control unit 146 receives a power signal 150 from the engine 102 or another system. The subject matter disclosed here is not limited to the power signal 150 being received by or generated by the engine 102, since the power signal 150 can also be received by other, in Fig. 1. Components not shown. The controller 146 receives the power signal 150 and adjusts the production of the pilot fuel 112 by the pilot fuel system 118 accordingly. For example, when the controller 146 receives the power signal 150, indicating that the engine 102 should produce more power, the pump controller 148 instructs the pilot fuel pump 122 to increase its flow rate. Similarly, when the controller 146 receives the power signal 150, indicating that the engine 102 should produce less power, the pump controller 148 instructs the pilot fuel pump 122 to decrease its flow rate. The control unit 146 can continue to use the fill level 142 to make further adjustments to the flow rate of the pilot fuel pump 122 in order to keep the fill level 142 within an operational range.

[0022] The controller 146 can have additional functions beyond maintaining the level 142 of the pilot fuel 112 in the accumulator 114 within an operational range. For example, the controller 146 can also control the flow rate of the waste pump 138. As mentioned above, the waste pump 138 is used to pump the liquefied methanol / water stream 136 from the separator 130 into the primary fuel distributor 110. However, if the flow rate of the waste pump 138 is greater than the production of the liquefied methanol / water stream, the amount of liquefied methanol / water in the separator 130 can drop to a level that causes the waste pump 138 to pump the produced pilot fuel 112 into the primary fuel distributor 110, and not just the liquefied methanol / water.If the flow rate of the waste pump 138 is less than the production of the liquefied methanol / water stream, the amount of liquefied methanol / water in the separator 130 can rise to a level that causes the separator 130 to overflow. Therefore, the pump controller 148 of the controller 146 increases or decreases the flow rate of the waste pump 138 to maintain a desired level of liquefied methanol / water in the separator 130.

[0023] The controller 146 is also used to control one or more valves that can be used in the system 100. For example, the controller 146 includes a valve controller 152. The valve controller 152 issues commands to various valves, such as the accumulator valve 154, the throttle valve 180, and the mixer 140. In some examples, the accumulator valve 154 may be a slide valve that allows the introduction of the produced pilot fuel 112 into the accumulator 114. However, in some examples, the system 100 may require that the accumulator 114 be fluidically isolated from the pilot fuel system 118. To provide fluidic isolation, the controller 152 instructs the accumulator valve 154 to close, thereby isolating the accumulator 114 from the pilot fuel system 118.This allows the separator 130 to be used for reducing waste (in this example, unreacted methanol and water) from the system 100. The system 100 can also reduce waste by reusing heat. As mentioned above, the heat from the products 121 is transferred, at least partially, to the pumped primary fuel 104 from the primary fuel tank 106 using the recuperator 124. However, in some examples, the additional components for thermal recovery may not be necessary or desirable, as exemplified in [reference]. Fig. 2 illustrated.

[0024] Fig. Figure 2 illustrates a system 200 in which heat energy is neither recycled nor recovered and a heating device is used to increase the temperature of the primary fuel 104, according to various examples of the subject matter disclosed herein. In the system 100 of Fig. 1. The recuperator 124 provides for the recovery of the thermal energy generated by the reactions in the reactor 120. The system 200 of Fig. 2 does not include heat recovery. Apart from the heat recovery of Fig. 1. The system works with 200 of Fig. 2 in a similar way to System 100 from Fig. 1. Therefore, some aspects of Fig. 2. Not described for reasons of brevity. In Fig. 2. System 200 comprises an engine 202. The engine 202 is an internal combustion engine that is operated with a primary fuel 204 stored in a primary fuel tank 206. The primary fuel 204 can, for example, comprise an alcohol fuel such as methanol or ethanol, or other types of fuel. For the purpose of illustrating an example of the subject matter disclosed herein, the primary fuel 204 is methanol. The primary fuel 204 is pumped by a primary fuel pump 208 into a primary fuel distributor 210.

[0025] In some examples, primary fuel 204 is a type of fuel with a comparatively low cetane / higher octane rating, which in the configuration shown in Fig. Figure 2 illustrates the use of a pilot fuel, such as pilot fuel 212, which is stored in a pilot fuel accumulator 214 via a pilot fuel distributor 216 to ignite the primary fuel 204. The pilot fuel 212 may be a liquid fuel with a higher cetane number / lower octane number, and the primary fuel 204 may be a liquid fuel with a lower cetane number / higher octane number. In system 200 of Fig. 2. Pilot fuel 212 is produced from primary fuel 204 using pilot fuel system 218. Thus, while primary fuel tank 206 stores primary fuel 204 for use by engine 202, primary fuel tank 206 also stores the fuel for producing pilot fuel 212, which is used by engine 202. To produce pilot fuel 212, in the example of Fig. 2 the primary fuel 204 in the reactor 220 of a dehydration reaction according to the above with regard to Fig. subjected to the equation shown in 1.

[0026] Since the dehydration reaction described above is an exothermic equilibrium, it follows that high conversion rates are achieved at the lowest possible reaction temperatures. From a reaction kinetics perspective, however, a higher temperature can increase the reaction rates and thus the DME conversion rates. To increase the temperature of the supplied primary fuel 104, a heating device 223 can be used. It should be noted that in some examples, if the temperature of the incoming primary fuel 204 is at a certain temperature (depending on the specific system configuration), the heating device 223 may not be necessary.

[0027] A pilot fuel pump 222 pumps a portion of the primary fuel 204 into the pilot fuel system 218. The pilot fuel pump 222 pumps the primary fuel 104 through the heating device 223 and finally into the reactor 220, where the primary fuel 204 is reacted to form the pilot fuel 212, in this example DME. To increase the temperature of the incoming primary fuel 204, a heating device 223 can be used to heat the incoming primary fuel 104 to a desired temperature. The heating device 223 can be used to raise the temperature of the primary fuel 204 to a temperature within a specific temperature range.In some examples, the temperature may be in a temperature range of 250 °C to 350 °C, and in others in a temperature range of 290 °C to 310 °C, although other temperature ranges may also be used, depending on the type of incoming primary fuel 204 or the catalyst used in the reactor 220. The heating device 223 may consist of various types of heat exchangers, including, but not limited to, a double-tube heat exchanger, a shell-and-tube heat exchanger, and / or a plate heat exchanger. The flow pattern within the heating device 223 may be, among others, counterflow, crossflow, or coflow.

[0028] As mentioned above, the heating device 223 uses the heat generated by the operation of the engine 202 to provide energy for raising the temperature of the primary fuel 204. In the Fig. In the example shown, the heating device 223 uses the engine exhaust 260. The engine exhaust 260 is exhaust gas from the engine 202, which is produced as a product of combustion within the engine. The engine exhaust 260 can be captured by various exhaust systems used for the engine 202. For example, the engine exhaust can be used before or after a turbocharger or an exhaust gas recirculation (EGR) system. In some examples, the engine exhaust 260 is used to indirectly heat the primary fuel 204, instead of directly heating the primary fuel 204 (as in Fig. 1 shown). In Fig. 2. The engine exhaust gas 260 enters an oil heat exchanger 262. The oil heat exchanger 262 is used to transfer heat from the engine exhaust gas 260 to an oil 264. In some examples, the oil 264 is a heat transfer fluid that can absorb heat from the engine exhaust gas 260. By way of example, and not as a limitation, the oil 264 includes, but is not limited to, silicone oil, hydraulic fluid, and some mineral oils. In the oil heat exchanger, the engine exhaust gas 260 transfers heat to the oil 264 and exits the oil heat exchanger 262 at outlet 266. The amount of engine exhaust gas 260 entering the oil heat exchanger 262 is controlled by means of the exhaust throttle valve 268. An oil pump 270 pumps the oil 264 from the oil heat exchanger 262 into the inlet 272 of the heating device 223. In the heating device 223, heat is transferred from the oil 264 to the primary fuel 204.The oil 264 enters the heating device 223 at the inlet 276 and exits the heating device 223 at the outlet 274. In the heating device 223, the primary fuel 204 is heated from an initial temperature at the inlet 276 to a higher temperature at an outlet 278. In some examples, the temperature of the primary fuel 204 at the outlet 278 is in a temperature range of 250 °C to 350 °C, and in some examples, in a temperature range of 290 °C to 310 °C. In some examples, the temperature of the primary fuel 204 at the outlet can be further increased using a heating device 280. The heating device 280 can be an electric heating device or a heating device that uses a flammable liquid such as propane, the pilot fuel 212, the primary fuel 204, and the like.

[0029] The output of reactor 220 comprises pilot fuel 212, water, and unreacted primary fuel 204. The output of reactor 220 enters a pressure regulator 226. The pressure regulator 226 maintains a pressure to ensure the liquefaction of at least some of the methanol and water into products 221. The products 221 then enter the condenser 228 to reduce their temperature (and in some examples, their pressure). It should be noted that in some examples, the methanol and water are liquefied mainly or exclusively in the condenser 228. Therefore, in these examples, the pressure regulator 226 cannot be used or installed. After the condenser 228, the products 221 are mainly methanol and water in liquid form and DME in gaseous form. The products 221 exit the condenser 228 and enter the separator 230.The gaseous DME 232 is pumped into the pilot fuel accumulator 214 by the product pump 234. The product pump 234 increases the pressure of the DME to condense the vaporous DME into liquid DME for storage within the accumulator 214. The methanol / water stream 236 is pumped through a mixer 240 into the primary fuel distributor 210 using the waste pump 238. The mixer 240 introduces the methanol / water stream 236 into the primary fuel 204, which is pumped into the primary fuel distributor 210 by the primary fuel pump 208.

[0030] The controller 246 maintains the level 242 of the pilot fuel 212 in the accumulator 214 above a specific level or within an operational range and also controls the heating of the primary fuel 204 in the heating device 223. When the controller 246 receives an input from the level detector 244 indicating that the level 242 is at or below a low setpoint, a pump controller 248 of the controller 246 instructs the pilot fuel pump 222 to increase its flow rate. When the controller 246 receives an input from the level detector 244 indicating that the level 242 is at or above a high setpoint, the pump controller 248 of the controller 246 instructs the pilot fuel pump 222 to decrease its flow rate. In some configurations, the control unit 246 can use a power requirement of the engine 102 to modify the production of pilot fuel 212.In these examples, the controller 246 receives a power signal 250 from the engine 102 or another system. The controller 246 receives the power signal 250 and adjusts the production of the pilot fuel 212 by the pilot fuel system 218 accordingly. For example, the pump controller 248 of the controller 246 instructs the pilot fuel pump 222 to increase the flow rate of the pilot fuel pump 222 when the controller 246 receives the power signal 250, which indicates a request for the engine 202 to produce more power. Similarly, the pump controller 248 of the controller 246 instructs the pilot fuel pump 222 to decrease the flow rate of the pilot fuel pump 222 when the controller 246 receives the power signal 250, which indicates that the engine 202 should produce less power.The control unit 246 can continue to use the fill level 242 to make further adjustments to the flow rate of the pilot fuel pump 222 in order to keep the fill level 242 within an operational range.

[0031] The control unit 246 can have additional functions beyond maintaining the level 242 of the pilot fuel 212 in the accumulator 214 within an operational range. For example, the control unit 246 can also control the flow rate of the waste pump 238. If the flow rate of the waste pump 238 is greater than the production of the liquefied methanol / water stream, the amount of liquefied methanol / water in the separator 230 can drop to a level that causes the waste pump 238 to pump the produced pilot fuel 212 into the primary fuel distributor 210, and not just the liquefied methanol / water. If the flow rate of the waste pump 238 is less than the production of the liquefied methanol / water stream, the amount of liquefied methanol / water in the separator 230 can rise to a level that causes the separator 230 to overflow.The pump controller 248 of the controller 246 increases or decreases the flow rate of the waste pump 238 to maintain a desired level of liquefied methanol / water in the separator 230. The controller 246 is also used to control one or more valves that can be used in the system 200. For example, the controller 246 includes a valve controller 252. The controller 252 issues commands to various valves, such as the accumulator valve 254. Fig. Figure 3 illustrates a procedure for which the control system, such as the control system 146 or the control system 246, can be operated to maintain the pilot fuel level in their respective systems.

[0032] Fig. Figure 3 illustrates a method 300 for operating an internal combustion engine 102, wherein a control unit 146 maintains a level 142 of the pilot fuel 112 in an accumulator 114, as shown in various examples of the subject matter disclosed herein. Method 300 and other processes described herein are illustrated as exemplary flowcharts, each operation being a sequence of operations that may be implemented in hardware, software, or a combination thereof. In the context of software, the processes represent computer-executable instructions stored on one or more tangible, computer-readable storage media, which, when executed by one or more processors, perform the aforementioned processes. In general, computer-executable instructions include routines, programs, objects, components, data structures, and the like, which perform specific functions or implement specific abstract data types.The order in which the processes are described is not to be understood as a restriction, and any number of the described processes can be combined in any order and / or in parallel with the implementation of the procedures.

[0033] Procedure 300 begins at step 302, where the controller 146 receives the level 142 of the pilot fuel 112 in the accumulator 114. The level 142 of the pilot fuel 112 in the accumulator 114 can be used to enable, but are not limited to, temporary events such as increasing or decreasing the power of the engine 102, starting the engine 102, and / or shutting down the engine 102. During use, the accumulator 114 acts as a buffer or "refill" tank, ensuring a consistent flow of the pilot fuel 112 into the pilot fuel distributor 116. The pilot fuel system 118 may not be able to increase or decrease the production of the pilot fuel 112 immediately or rapidly.Furthermore, the temperature of the pilot fuel system 118 may be reduced during start-up, resulting in insufficient conversion efficiency within the reactor 120 to produce the pilot fuel 112. Therefore, the pilot fuel 112 stored in the accumulator 114 prior to engine shutdown can be used while the pilot fuel system 118 heats up to a desired operating temperature. Additionally, the pilot fuel 112 in the accumulator 114 can be used during engine shutdown to assist in draining the primary fuel 104 from the engine 102. The fill level 142 can be maintained within an operational range, from a low setpoint indicating a low fill level to a high setpoint indicating a high fill level.

[0034] Procedure 300 proceeds to step 304, in which the controller 146 determines whether a condition has been detected that requires a change in the production rate of the pilot fuel 112. A condition may include, among other things, reaching a low or high setpoint level of 142, shutting down the engine, or changing the required power output of the engine 102, as indicated by the power signal 150. If no condition is received, the procedure continues with step 302, in which the controller 146 continues to receive the pilot fuel levels in the accumulator.

[0035] If, in step 304, a condition is detected that requires a change in the production of pilot fuel 112, the procedure 300 proceeds to step 306, in which the controller 146 determines whether the production rate of pilot fuel 112 should be increased, decreased, or maintained. The determination of whether or not to adjust the production rate of pilot fuel 112 is based, in some examples, on whether the condition indicates that the level in the accumulator is changing to a level above or below a certain setpoint, or that such a change is expected. For example, the condition might be an increase in the power required by the engine 102. This indicates that an increased quantity of pilot fuel 112 produced may be necessary to maintain the level of pilot fuel 112 in the accumulator above a low setpoint.Similarly, the condition could be a reduction in the power required by engine 102. This indicates that a smaller quantity of pilot fuel 112 produced might be necessary to maintain the level of pilot fuel 112 in the accumulator below a high target value.

[0036] If the controller determines in step 306 that the production rate of the pilot fuel 112 is to be maintained at its current level, the procedure 300 continues with step 308, in which the controller 146 does not initiate any changes to the pump speeds or make any other changes to the configuration of the system 100. The procedure 300 continues with step 302, in which the controller 146 continues to receive the fill level 142 of the pilot fuel 112 in the accumulator 114.

[0037] If, at step 306, the controller 146 determines that a reduction in the pilot fuel 112 production rate is necessary to maintain the pilot fuel level in the accumulator below a high setpoint, the procedure 300 proceeds to step 310, in which the controller 146 reduces the pilot fuel 112 production rate. The pump controller 148 of the controller 146 instructs the pilot fuel pump 122 to reduce its flow rate so that the pilot fuel 112 level in the accumulator is maintained at or near a certain level, in some examples at the level detected in step 302 prior to the state detection in step 304. The reduced flow rate of the pilot fuel pump 122 decreases the pilot fuel 112 production.

[0038] Procedure 300 continues to step 312, in which the controller 146 determines whether the level 142 of the pilot fuel 112 is within an operational range. If the controller 146 determines in step 314 that the level 142 is within the operational range, procedure 300 continues to step 308 and maintains the production rate of the pilot fuel 112. If the controller 146 determines in step 314 that the level 142 of the pilot fuel 112 is not within the operational range, the procedure continues to step 306, in which the controller 146 determines whether to increase, decrease, or maintain the production rate of the pilot fuel 112.

[0039] If, at step 306, the controller 146 determines that the production rate of the pilot fuel 112 is to be increased, the procedure 300 proceeds to step 314, in which the controller 146 increases the production rate of the pilot fuel 112 so that the level of the pilot fuel 112 in the accumulator is maintained at or near a level, in some examples at the level determined at step 302 prior to the state detection at step 304. A pump controller 148 of the controller 146 instructs the pilot fuel pump 122 to increase its flow rate. The increased flow rate of the pilot fuel pump 122 increases the production of the pilot fuel 112.The controller 146 can determine a rate of change of the fill level 142, whereby a higher rate of change causes the pump controller 148 of the controller 146 to increase the flow rate (or speed) of the pilot fuel pump 122 to a certain flow rate or to increase the flow rate at a certain speed (i.e., to increase the speed quickly), based on the rate of change of the fill level 142.

[0040] Procedure 300 continues to step 312, in which the controller 146 determines whether the level 142 of the pilot fuel 112 is within an operational range. If the controller 146 determines in step 314 that the level 142 is within the operational range, procedure 300 continues to step 308 and maintains the production rate of the pilot fuel 112. If the controller 146 determines in step 314 that the level 142 of the pilot fuel 112 is not within the operational range, the procedure continues to step 306, in which the controller 146 determines whether to increase, decrease, or maintain the production rate of the pilot fuel 112.

[0041] Fig. Figure 4 shows a component-level view of the controller 146 for use with the systems and methods described herein, according to various examples of the present disclosed subject matter. The controller 146 can be any device that provides the functions associated with the systems and methods described herein. The controller 146 can comprise several components for performing the aforementioned functions. The controller 146 can consist of hardware, software, or various combinations thereof. As described below, the controller 146 can comprise memory 402, including an operating system (OS) 404, and one or more standard applications 406. The standard applications 406 can include applications that provide pump control 148 or valve control 152, as well as receiving and storing signals such as the power signal 150 and the level 142.

[0042] The controller 146 can also include one or more processors 410 and one or more removable memories 412, non-removable memories 414, transceivers 416, output device(s) 418, and input device(s) 420. In various implementations, the memory 402 can be volatile (e.g., random-access memory (RAM)), non-volatile (e.g., read-only memory (ROM), flash memory, etc.), or a combination of both. The memory 402 can contain data relating to signals such as the power signal 150 and the fill level 142, as well as other information, and can be stored on a remote server or in a cloud of servers that the controller 146 can access.

[0043] Memory 402 can also include OS 404. OS 404 varies depending on the manufacturer of the controller 146. OS 404 contains the modules and software that support basic functions of the controller 146, such as scheduling tasks, application execution, and control of peripheral devices. OS 404 can also enable the controller 146 to send and receive other data and perform other functions, such as the power signal 150 and the level signal 142, as well as instructions from the pump controller 148 or the valve controller 152.

[0044] The Controller 146 can also include one or more Processors 410. In some implementations, the Processor(s) 410 can be one or more central processing units (CPUs), graphics processing units (GPUs), both CPU and GPU, or any other combination and number of processing units. The Controller 146 can also include additional (removable and / or non-removable) data storage, such as magnetic disks, optical disks, or tapes. Such additional storage is in Fig. 4 illustrated by removable storage 412 and non-removable storage 414.

[0045] Non-volatile, computer-readable media can include volatile and non-volatile, removable and non-removable tangible physical media implemented in technologies for storing information, such as computer-readable instructions, data structures, program modules, or other data. Memory 402, Removable Storage 412, and Non-Removable Storage 414 are all examples of non-volatile, computer-readable media. Non-volatile, computer-readable media include, but are not limited to, RAM, ROM, electronically erasable programmable ROM (EEPROM), flash memory, or other storage technologies; Compact Disc ROM (CD-ROM); Digital Versatile Discs (DVDs); or other optical storage media; magnetic cartridges, magnetic tapes, magnetic disk storage, or other magnetic storage devices; or any other tangible physical medium that can be used to store the desired information and that the controller 146 can access.Each of these non-volatile, computer-readable media can be part of Control 146 or a separate database, database, remote server, or cloud-based server.

[0046] In some implementations, the transceiver(s) 416 encompass all transceivers known in the technology. In some examples, the transceiver(s) 416 may include one or more wireless modems to enable wireless communication with other components (e.g., between the controller 146 and one or more pumps or valves), the internet, and / or an intranet. Specifically, the transceiver(s) 416 may include one or more transceivers that allow the controller 146 to send and receive data. Thus, the transceiver(s) 416 may include multiple single-channel transceivers or a multi-frequency multi-channel transceiver to enable the controller 146 to send and receive video calls, audio calls, messages, and so on. The transceiver(s) 416 can enable the controller 146 to connect to multiple networks, including but not limited to 2G, 3G, 4G, 5G and WLAN networks.The transceiver(s) 416 may also include one or more transceivers to enable the controller 146 to connect to future (e.g. 6G) networks, Internet of Things (IoT), machine-to-machine (M2M) and other current and future networks.

[0047] The 416 transceiver(s) may also include one or more radio transceivers that perform the function of sending and receiving high-frequency communication via an antenna (e.g., WLAN or Bluetooth). ®) execute. In other examples, the transceiver(s) 416 may include wired communication components, such as a wired modem or an Ethernet port, to communicate over one or more wired networks. The transceiver(s) 416 may enable the controller 146 to make audio and video calls, download files, access web applications, and provide other communications associated with the systems and procedures described above.

[0048] In some implementations, the output device(s) 418 include all output devices known in the art, such as a display (e.g., a liquid crystal or thin-film transistor (TFT) display), a touchscreen, a speaker, a vibration mechanism, or a tactile feedback mechanism. Thus, the output device(s) may include a screen or display. The output device(s) 418 may also include speakers or similar devices to play sounds or ringtones when an audio or video call is received. The output device(s) 418 may also include connectors for one or more peripheral devices, such as headphones, peripheral speakers, or a peripheral display.

[0049] In various implementations, the input device(s) 420 include any input device known in the art. The input device(s) 420 may include, for example, a camera, a microphone, or a keyboard. The input device(s) 420 may include a touch-sensitive display or a keyboard to enable users to enter data, make requests and receive responses via web applications (such as in a web browser), make audio and video calls, and use the standard applications 406. A touch-sensitive display or keyboard / keypad may be a standard alphanumeric multi-key keyboard (such as a conventional QWERTY keyboard), virtual controls on a touchscreen, or one or more other types of keys or buttons, and may also include a joystick, a wheel, and / or certain navigation keys or the like.A touch-sensitive display can serve as both an input device 420 and an output device 418. Commercial applicability

[0050] The present disclosure relates generally to internal combustion engines that use a pilot fuel to assist the ignition of a primary fuel. The respective in Fig. 1 and Fig.Two illustrated systems, 100 and 200, use primary fuel 104 as the source for pilot fuel 112. Primary fuel 104 undergoes a dehydration reaction to produce pilot fuel 112. Using primary fuel as the fuel source for pilot fuel production allows a single storage system, i.e., the primary fuel tank 106, to be used as the source for both fuels in a dual-fuel system. This can help reduce the number of components required to operate engine 102. This can be advantageous in applications where space is limited (e.g., in a work machine) or where a reduction in components is desired for cost or safety reasons.

[0051] One or more heat exchangers 123A / 123B are used to raise the temperature of the primary fuel to an operating temperature of the reactor 120. Raising the primary fuel temperature to an operating temperature can increase the efficiency of the reactor 120. The heating device utilizes fluids from the engine that would otherwise require cooling, i.e., waste heat. One type of fluid can be an engine lubricant, used for lubrication and to dissipate heat generated by combustion and friction from the engine. Another type of fluid can be the exhaust gas produced during engine combustion. Other fluids that absorb heat during engine operation can be used and are considered to fall within the scope of the subject matter disclosed herein. Utilizing heat sources from the engine that would otherwise go unused can increase the efficiency of the pilot fuel system.The systems described here use the accumulator 114 to serve as a buffered source of pilot fuel 112 during transient conditions, such as increases or decreases in power. Furthermore, the accumulator 114 can be used as a source of pilot fuel 112 during startup. The controller 146 can adjust the production rate of the pilot fuel 112 by the pilot fuel system 118 to maintain the level 142 of the pilot fuel 112 in the accumulator 114 within an operational range. By using the accumulator 114 in this way, the required rate of change of production of the pilot fuel system 118 can be reduced. This reduced rate of change of production can decrease the thermal stresses on the pilot fuel system 118, potentially increasing its service life and reducing the overall failure rate of the systems.Unless expressly excluded, the use of the singular to describe a component, structure, or process does not preclude the use of the multitude of such components, structures, or processes, or their equivalents. As used herein, the word "or" refers to any possible permutation of a set of elements. For example, the phrase "A, B, or C" refers to at least one of A, B, C, or any combination thereof, such as any of the following: A; B; C; A and B; A and C; B and C; A, B, and C; or multiples thereof, such as A and A; B, B, and C; A, A, B, C, and C; etc.

[0052] While aspects of the present disclosure have been shown and described in particular with reference to the foregoing embodiments, it is obvious to those skilled in the art that various additional embodiments can be considered by modifying the disclosed machines, systems, and methods without departing from the meaning and scope of the disclosure. These embodiments shall be understood as falling within the scope of the present disclosure as determined on the basis of the claims and any correspondences thereto. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] EP 419743A1

[0004]

Claims

[1] System (100), comprising: an internal combustion engine (102) which consumes a primary fuel (104) and a pilot fuel (112); a primary fuel tank (106) which supplies the primary fuel (104) to a primary fuel distributor for use by the internal combustion engine (102); a pilot fuel system (118) designed to produce the pilot fuel (112) from the primary fuel (104), comprising the pilot fuel system (118): a pilot fuel pump (122) which is fluidically connected to the primary fuel tank (106), wherein the pilot fuel pump (122) is configured to pump the primary fuel (104) from the primary fuel tank (106) to a reactor (120) of the pilot fuel system (118); the reactor (120) which receives the primary fuel (104) from the pilot fuel pump (122), wherein the reactor (120) is configured to convert the primary fuel (104) received from the pilot fuel pump (122) from an alcohol into an ether, wherein a product (121) of the reactor (120) comprises the pilot fuel (112), unreacted primary fuel (104) and water; a condenser (128) which receives the product (121) of the reactor (120), wherein the condenser (128) is configured to condense the unreacted primary fuel (104) and the water in the product (121) received by the reactor (120) into liquefied unreacted primary fuel (104) and water; a separator that receives the liquefied, unreacted primary fuel (104) and water and the pilot fuel (112), wherein the separator is configured to separate the pilot fuel (112) from the liquefied, unreacted primary fuel (104) and water; a waste pump that receives the liquefied, unreacted primary fuel (104) and water from the separator, the waste pump being configured to pump the liquefied, unreacted primary fuel (104) and water to the primary fuel distributor; a product pump (134) that receives the pilot fuel (112) from the separator, the product pump (134) being configured to pump the pilot fuel (112) converted from the primary fuel (104) to an accumulator (114) for use by the internal combustion engine (102); and a heating device (280) that receives the primary fuel (104), wherein the heating device (280) is configured to heat the primary fuel (104) pumped into the pilot fuel system (118) to an operating temperature of the reactor (120) using engine waste heat; and a control (146) for maintaining a level of the pilot fuel (112) stored in the accumulator (114) within an operational range. [2] System (100) according to claim 1, wherein the use of the engine waste heat comprises: Taking the engine exhaust gases (260) from the engine (102) into the heating device (123A); Exchange of heat from the engine exhaust (260) into the primary fuel (104) in the heating device (123A); and Discharge of the primary fuel (104) from the heating device (123A) at operating temperature into the reactor (120). [3] System (100) according to claim 2, further comprising a throttle valve (180) configured to increase or decrease the flow of the engine exhaust gas (260) in order to control the rate of temperature increase of the primary fuel (104) in the heating device (123A). [4] System (100) according to claim 1, wherein the use of the engine waste heat comprises: Collecting the engine exhaust gases (260) from the engine (102) into an oil heating device (262); Exchange of heat from the engine exhaust (260) into the oil circulating in the heating device (262) to increase the temperature of the oil; Pumping the oil from the oil heating device (262) to the heating device (280) using a pump; and Exchange of heat from the oil into the primary fuel (104) in the heating device (280) to raise the temperature of the heating device (280) to the operating temperature. [5] System (100) according to claim 1, further comprising a second heating device (123B) in fluid connection with the primary fuel tank (106), wherein the second heating device (123B) is configured to increase the temperature of the primary fuel (104) from the fuel tank from an initial temperature to an operating temperature using a second engine waste heat, wherein the second engine waste heat comprises heat from a lubricant of the engine (102), and wherein the initial temperature is in a first temperature range of 78 °C to 82 °C and the operating temperature is in a second temperature range of 290 °C to 310 °C. [6] System (100) according to claim 1, wherein the primary fuel (104) comprises methanol and the pilot fuel (112) comprises dimethyl ether. [7] System (100) according to claim 1, further comprising a recuperator which absorbs the product of the reactor (120) in order to transfer heat of the product of the reactor (120) to the primary fuel (104) which is pumped into the pilot fuel system (118). [8] Method for operating an internal combustion engine (102), comprising: Conveying a primary fuel (104) from a primary fuel tank (106) into a first heating device (123A) of a pilot fuel system (118); Exchange of heat between the primary fuel (104) in the first heating device (123A) and a first fluid from the engine (102) to raise the temperature of the primary fuel (104) from an initial temperature to a first temperature; Directing the primary fuel (104) at the first temperature into a second heating device (123B); Exchange of heat between the primary fuel (104) in the second heating device (123B) and a second fluid from the engine (102) to raise the temperature of the primary fuel (104) in the second heating device (123B) from the first temperature to a second temperature; Directing the primary fuel (104) from the second heating device (123B) into a reactor (120); and Converting the primary fuel (104) in the reactor (120) into a pilot fuel (112) by a dehydration reaction in the reactor (120). [9] Method according to claim 8, wherein the first liquid comprises an engine lubricant and the second liquid comprises engine exhaust (260) produced by combustion in the engine (102). [10] The method of claim 8, further comprising: Received, by a control (146), a level of the pilot fuel (112) in an accumulator (114), wherein the pilot fuel (112) consumed by the internal combustion engine (102) is produced by converting a primary fuel (104) consumed by the internal combustion engine (102) into the pilot fuel (112) using a dehydration reaction in a reactor (120); Detect, by control (146), a state in which a change in the production rate of the pilot fuel (112) by a pilot fuel system (118) is required; Determine, by control (146) based on the detection of the condition that the production rate of the pilot fuel (112): is to be reduced by transmitting a first pump control signal to reduce the speed of a pilot fuel pump (122) from a first pump speed to a second pump speed, wherein the second pump speed is lower than the first pump speed, wherein the pilot fuel pump (122) is fluidically connected to a primary fuel tank (106) which stores the primary fuel (104), wherein the pilot fuel pump (122) is configured to pump the primary fuel (104) from the primary fuel tank (104) to the reactor (120); to be increased by sending a second pump control signal to increase the speed of the pilot fuel pump (122) from the first pump speed to a third pump speed, the third pump speed being higher than the first pump speed; or to be maintained at the first pump speed.

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