LIQUID INJECTION SYSTEM, LIQUID INJECTION ENGINE SYSTEM AND METHOD FOR CONTROLLING A LIQUID INJECTION SYSTEM

Abstract

Systems and methods include processing circuitry comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to receive temperature information indicative of a temperature within an air inlet, receive humidity information indicative of an inlet air humidity at the air inlet, receive pressure information indicative of an air pressure within the air inlet, determine a dew point temperature limit based on the temperature information, the humidity information, and the pressure information, determine an exhaust emission performance, determine a liquid flow rate based on the dew point temperature limit,wherein the liquid flow rate reduces the exhaust emission performance, and to control at least one pump or valve to provide the liquid flow rate.,

Description

FIELD

[0001] The present disclosure generally relates to humidification systems for engines. More specifically, the present disclosure relates to liquid injection control systems for engines. BACKGROUND

[0002] Many engine systems have air intake systems that are susceptible to water ingress. Water ingress can lead to corrosion, and moisture can also affect the components of such systems. SUMMARY

[0003] One embodiment relates to a liquid injection system for an engine system comprising one or more processing circuits including one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: receive temperature information indicative of a temperature within an air intake; receive humidity information indicative of an inlet air humidity at the air intake; receive pressure information indicative of an air pressure within the air intake; determine a dew point temperature limit based on the temperature information, the humidity information, and the pressure information; determine an exhaust emission performance;determine a fluid flow rate based on the dew point temperature limit, the fluid flow rate allowing a reduction in exhaust emission performance; and control at least one pump or injector to provide the fluid flow rate.;

[0004] Another embodiment relates to a liquid-injected engine system comprising a water manifold, a water tank, a water pump fluidly coupled to the water tank, a water solenoid valve selectively coupling a water injector to the water pump, and a controller configured to determine a dew point temperature limit based on temperature, pressure, and humidity information of the water manifold, determine a condensation margin limit based on the dew point temperature limit, determine a liquid flow rate based on the dew point temperature limit and the condensation voltage limit, and control the water pump and the water solenoid valve to provide the liquid flow rate to the water injector.

[0005] Another embodiment relates to a method for controlling a liquid injection system for an engine. The method includes receiving temperature information indicative of a temperature within an air intake, receiving humidity information indicative of an intake air humidity at the air intake, receiving pressure information indicative of an air pressure within the air intake, determining a dew point temperature limit based on the temperature information, the humidity information, and the pressure information, determining an exhaust emission performance, determining a liquid flow rate based on the dew point temperature limit, the liquid flow rate allowing a reduction in the exhaust emission performance, and controlling at least one pump or water solenoid valve to provide the liquid flow rate.

[0006] It should be understood that any combination of the foregoing concepts and additional concepts discussed in more detail below may be considered part of the subject matter disclosed herein. In particular, any combination of claimed subject matter appended to the end of this disclosure is considered part of the subject matter disclosed herein. BRIEF DESCRIPTION OF THE NUMBERS

[0007] The foregoing and other features of the present disclosure will become more apparent from the following description and the appended claims, taken in conjunction with the accompanying drawings. Recognizing that these drawings illustrate only some embodiments according to the disclosure and are therefore not to be considered limiting of its scope, the disclosure is described with additional specificity and detail with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a liquid-injected engine system according to some embodiments. Fig. Figure 2 is a schematic diagram of a controller for the liquid injection engine system of Fig. 1, according to some embodiments. Fig. 3 is a flowchart of the control logic processing of the controller of Fig. 2, according to some embodiments. Fig. 4 is a flowchart of a method of operating the liquid injection engine system of Fig. 1, according to some embodiments. Fig. 5 is a flowchart of the method of operating the liquid injection engine system of Fig. 1, according to some embodiments. Fig. 6 is a flowchart of the method of operating the liquid injection engine system of Fig. 1, according to some embodiments.

[0008] In the following detailed description, reference is made to the accompanying drawings described above. In the drawings, like symbols generally refer to like components unless the context dictates otherwise. The example implementations described in the following detailed description, drawings, and claims are not to be considered limiting. Other embodiments may be utilized and other changes may be made without affecting the spirit or scope of the subject matter presented herein. It is to be understood that the aspects of the present disclosure, as generally described herein and illustrated in the figures, may be arranged, substituted, combined, and configured in a variety of different configurations, all of which are expressly contemplated and made a part of this disclosure. DETAILED DESCRIPTION

[0009] The following describes in more detail various concepts and implementations of methods and systems for controlling a liquid injection system for an engine system.

[0010] Referring generally to the figures, the various embodiments disclosed herein relate to systems and methods that provide in-engine solutions for reducing engine exhaust emissions without the use of exhaust aftertreatment systems. Many existing engines used in data centers and other facilities to power generator sets are required to provide high performance and be fuel efficient. Many of these engines require an exhaust aftertreatment system to achieve required nitrogen oxide (NOx) emission levels (e.g., as specified by a regulatory agency). An engine humidification system, as described herein, can reduce NOx emissions from standby diesel generator sets or other engines. The system injects a fine mist of liquid, such as water, downstream of a turbocharger to increase the humidity of the combustion air.Although reference is made to water in the examples below, it should be noted that the techniques described herein are not limited to water and are applicable to other liquids. In some embodiments, the liquid injection system may provide a reduction in NOx emissions (compared to a system without liquid injection). The control techniques described herein allow for a reduction in emissions, particularly NOx emissions. In some embodiments, a NOx reduction of about 5% to about 40%, from about 10% to about 20%, from about 10% to about 30%, or from about 10% to about 40% may be achieved.

[0011] In some embodiments, the liquid injection system determines a dew point temperature limit in a water manifold, as explained in more detail below. In some embodiments, once the dew point temperature limit is determined, the liquid injection system performs control to reduce NOx emissions. Such control to reduce NOx emissions can be performed while preventing condensation in the water manifold. In some embodiments, no additional sensors are used to operate the liquid injection system beyond the sensors already provided with the engine (e.g., a "Trican" sensor, a "Tri-Sensor," or a "Combination Sensor," as explained in more detail below). Therefore, such a system is suitable for retrofitting older engines that would otherwise need to be replaced or expensively retrofitted to comply with changing emissions regulations.

[0012] As in Fig. 1, a liquid-injected engine system 10 includes an engine 14 that includes a fresh air intake 18, an exhaust outlet 22, and a water manifold 26. In some embodiments, the engine 14 is a turbocharged engine that includes air crossover tubes and shutoff plates. For example, the liquid-injected engine system 10, as shown in Fig. 1, a first shutoff plate (shutoff plate 1), a second shutoff plate (shutoff plate 2), and two pairs of air transition tubes. The first pair includes, for example, an air transition tube 1 and an air transition tube 2 located opposite each other on opposite sides of the exhaust stack 22. The second pair includes an air transition tube 3 and an air transition tube 4 located on opposite sides of a manifold pressure sensor 190 and on an opposite side of the shutoff plates (shutoff plate 1 and shutoff plate 2) of the first pair of air transition tubes.

[0013] In some embodiments, engine 14 is an internal combustion engine that provides mechanical power to a generator as part of a generator set for providing electrical energy. For example, engine 14 may be part of a generator that powers a structure, plant, or facility that requires energy. The structure, plant, or facility may be, for example, a data center, another building, a marine generator set, or a locomotive generator set, or engine 14 may be configured as an engine in another system, as desired. In some embodiments, data centers may be located in remote locations or have high energy demands that require a large number of generator sets.The liquid-injected engine system 10 is designed to provide mechanical power while reducing the production of emissions such as NOx exiting the exhaust outlet 22. In many locations, it is desirable to keep emissions from the exhaust outlet 22 below a threshold level. Furthermore, in some cases, it is advantageous to achieve the desired emission levels without the use of complex aftertreatment systems or with a reduction in the number of such aftertreatment systems. The liquid-injected engine system 10 utilizes liquid injection into the water receiver 26 to reduce the NOx emissions produced by the engine 14 without the use of an aftertreatment system.

[0014] Furthermore, in some embodiments, various components described above may be combined with other components in a liquid-injected engine system. For example, in some embodiments, a liquid-injected engine system 30 of the liquid-injected engine system 10 includes a water manifold 26, a water tank 34, a water pump 46, a water solenoid valve 66 connecting a water injector 70 to the water pump 46, and a regulator 100.As described in more detail below, the controller 100 is configured to determine a dew point temperature limit based on temperature, pressure, and humidity information from the water manifold; determine a condensation margin limit based on the dew point temperature limit; determine a fluid flow rate based on the dew point temperature limit and the condensation margin limit; and control the water pump 46 and the water solenoid valve 66 to provide the fluid flow rate to the injector 70.

[0015] As mentioned above, in some embodiments, the liquid injection system 30 of the liquid injection engine system 10 includes the water tank 34. In some embodiments, the water tank 34 is arranged to receive a water flow from a reverse osmosis system 38 or other water treatment system. In some embodiments, the water treatment system is omitted. In some embodiments, the water tank 34 is periodically filled. In some embodiments, the water tank 34 is filled at regular intervals and is not connected to a continuous water supply.

[0016] In some embodiments, the water from the water tank 34 is filtered through a water filter or strainer 42 before being fed to the pump 46. The pump 46 is driven by a motor 50. In some embodiments, the motor 50 is an alternating current (AC) motor. A pressure relief valve 58 receives power from the pump 46 and redirects the water back into the water tank 34 when the pressure exceeds a threshold water system pressure.

[0017] The pressurized water coming from pump 46 is in turn filtered through a water filter or strainer 62 and received by a magnetically actuated metering valve 66, which may be configured as a water solenoid valve. Solenoid valve 66 provides water to injectors 70 within manifold 26. Injectors 70 provide a water mist in a fuel stream that is combusted by engine 14 in manifold 26.

[0018] In some embodiments, controller 100 is configured to communicate with one or more actuators and one or more sensors of liquid-injected engine system 10. Controller 100 controls the operation of solenoid valve 66 to provide water to injectors 70, a variable frequency drive (VFD) 184 to drive motor 50, and a human-machine interface (HMI) 180. Water pump 46 may be controlled, e.g., by sending control commands to VFD 184, to provide fluid flow. Controller 100 receives information from sensors and controls liquid injection system 30 to reduce emissions. In some embodiments, controller 100 operates liquid injection system 30 to reduce emissions while reducing or preventing the formation of condensate within the manifold.The controller 100 determines a dew point temperature and a dew point pressure, sets a limit value relative to the determined dew point temperature and the determined dew point pressure, and controls the fluid flow to the injectors 70 to reduce emissions while maintaining conditions below the limit value.

[0019] Since the Fig. 1 are integrated into the liquid-injected engine system 10, the controller 100 may be configured as one or more electronic control units (ECUs). The controller 100 may be separate from, or integrated with, an exhaust aftertreatment control unit, a generator control module, or an engine control module, etc., alone or in any combination. The function and structure of the controller 100 are described in Fig. 2 described in more detail.

[0020] In Fig. 2 is a schematic diagram of the controller 100 of the liquid injection engine system 10 of Fig. 1 according to an exemplary embodiment. As in Fig. 2, the controller 100 includes a processing circuit 104 having a processor 108 and a memory device 112, a control system 116 having an analog input circuit 120, a digital input circuit 124, a data input circuit 128, a dew point circuit 132, a pressure circuit 136, a condensation margin limit 140, a margin circuit 144, and an output circuit 148, and a communications interface 152. In general, the controller 100 is configured to determine a dew point temperature and pressure of the water manifold 26, determine a margin limit related to the determined dew point temperature and pressure, and control the liquid injection system 30 to reduce engine emissions while maintaining conditions within the manifold 26 below the margin limit.

[0021] The controller 100 is communicatively connected to a variety of sensors. In some embodiments, the controller 100 is configured to communicate, for example, with at least one water pressure sensor, at least one temperature sensor, and at least one water tank level sensor. In some embodiments, the controller 100 is configured to communicate with a water pressure sensor 156 positioned to measure the pressure of the water at the injectors 70, a temperature sensor 160 positioned in the exhaust stream, a water tank level sensor 164, a VFD fault reset 168, the solenoid valve 66, the HMI 180, the pump VFD 184, and one or more routers. For example, the controller 100 is configured to communicate with an information router in the form of a communication control interface 176 and an information router in the form of a gateway 188.The gateway 188 is configured to receive information from at least one manifold pressure sensor 190, a NOx sensor 192 located in the exhaust outlet 22, and a combination sensor 196. In some embodiments, information from at least the NOx sensor 192 is displayed on the HMI 180. In some embodiments, the gateway 188 is a gateway that complies with the Society of Automotive Engineers J1939 standards for a communication vehicle network. In some embodiments, the combination sensor 196 may be configured to measure three primary parameters and is also referred to as a "tri-sensor."

[0022] In some embodiments, the combination sensor 196 is configured as a pressure, temperature, and humidity sensor 196 positioned in the engine intake 18 to measure intake air temperature, intake air humidity, and intake air pressure. The liquid-injected engine system 10 may include other sensors that provide information to the controller 100. The humidity measured by sensor 196 may be relative humidity. For example, a boost pressure sensor and a manifold temperature sensor may be included. In some embodiments, the controller 100 is configured to communicate with a sensor array of an engine system 10 provided by a third party (e.g., a vendor) that is not the supplier of the controller 100. The controller 100 is structured to receive the available information from the sensor array and provide the control functions discussed herein.

[0023] In one configuration, the circuitry of control system 116 is embodied as machine- or computer-readable media executable by a processor, such as processor 108. As described herein, and among other uses, the machine-readable media facilitates the performance of certain operations to enable the reception and transmission of data. For example, the machine-readable media may provide an instruction (e.g., a command, etc.) to, for example, acquire data. In this context, the machine-readable media may include programmable logic that determines the frequency of data acquisition (or data transmission).The computer-readable media may contain code written in any programming language, including, but not limited to, Java or similar languages ​​and conventional procedural programming languages, such as the C programming language or similar programming languages. The computer-readable program code may be executed on a single processor or on multiple remote processors. In the latter case, the remote processors may be interconnected via any type of network (e.g., CAN bus, etc.).

[0024] In another configuration, the circuitry of control system 116 is embodied as hardware units, e.g., as electronic control units. As such, the circuitry of control system 116 may be embodied as one or more circuit components, including, but not limited to, processing circuitry, network interfaces, peripherals, input devices, output devices, sensors, etc. In some embodiments, the circuitry of control system 116 may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (ICs), discrete circuits, system-on-a-chip (SOCs), microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of "circuitry." In this regard, the circuitry of control system 116 may include any type of component that enables or facilitates the operations described herein.For example, a circuit described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, etc. The circuits of the control system 116 may also include programmable hardware devices such as field-programmable gate arrays, programmable array logic, programmable logic devices, or the like. The circuits of the control system 116 may include one or more memory devices for storing instructions executable by the processor(s) of the circuits of the control system 116. The one or more memory devices and the processor(s) may have the same definition as provided below with respect to the memory device 112 and the processor 108.In some hardware unit configurations, the circuitry of control system 116 may be distributed across various locations within a structure. Alternatively, and as illustrated, the circuitry of control system 116 may be housed in a single unit / casing, depicted as controller 100.

[0025] In the Fig. 2, the controller 100 includes the processing circuit 104 with the processor 108 and the memory device 112. The processing circuit 104 may be structured or configured to execute or implement the instructions, commands, and / or control methods described herein with respect to the circuits of the control system 116. The illustrated configuration depicts the circuits of the control system 116 as machine- or computer-readable media. However, as previously mentioned, this depiction is not to be understood as limiting, as the present disclosure also contemplates other embodiments in which one or more of the circuits of the control system 116, or at least one circuit of the circuits of the control system 116, is configured as a hardware unit. All such combinations and variations are intended to be within the scope of the present disclosure.

[0026] The hardware and data processing components used to implement the various processes, operations, illustrative logic, logical blocks, modules, and circuits (e.g., the processing circuitry 104 provided with the processor 108) described in connection with the embodiments disclosed herein may be implemented or embodied using a general-purpose single-chip or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof to perform the functions described herein. A general-purpose processor may be a microprocessor or a state machine. A processor may also be implemented as a combination of computing units, such asa combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or other such configuration. In some embodiments, the one or more processors may be shared by multiple circuits (e.g., circuits of control system 116 may include or otherwise share the same processor, which, in some embodiments, may execute instructions stored or otherwise accessed across different memory locations). Alternatively or additionally, the one or more processors may be structured to perform or otherwise execute certain operations independently of one or more coprocessors.In other embodiments, two or more processors may be coupled via a bus to enable independent, parallel, pipelined, or multithreaded instruction execution. All such variations are within the scope of the present disclosure.

[0027] The storage device 112 (e.g., memory, storage unit, storage device) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and / or computer code to complete or facilitate the various processes, layers, and modules described in the present disclosure. The storage device 112 may be communicatively coupled to the processor 108 to provide computer code or instructions to the processor 108 to perform at least some of the processes described herein. Furthermore, the storage device 112 may be or include tangible, non-transient volatile memory or non-volatile memory.Accordingly, the storage device 112 may include database components, object code components, script components, or any other type of information structure to support the various activities and information structures described herein.

[0028] In some embodiments, analog input circuit 120 is configured to receive an injection water pressure from water pressure sensor 156 and an exhaust stack temperature from temperature sensor 160. In some embodiments, analog input circuit 120 includes a thermocouple-to-analog input converter. Analog input circuit 120 is configured to receive information from other analog sensors or systems of engine system 10.

[0029] In some embodiments, the digital input circuit 124 is configured to receive information from the water tank level sensor 164 and other digital sensors or systems of the engine system 10. For example, the data input circuit 128 is structured to receive information from the communication control interface 176, the HMI 180, the pump VFD 184, and a gateway 188. In some embodiments, the communication control interface 176 provides engine speed, total engine load or generator load (e.g., in kW), boost pressure, intake manifold pressure, and generator status. In some embodiments, the communication control interface 176 is configured to provide information related to generator load and engine temperature. In some embodiments, the communication control interface 176 may provide other information as desired.In some embodiments, the gateway 188 provides, among other things, various inlet and outlet information.

[0030] For example, in some embodiments, gateway 188 provides exhaust passage pressure and intake air information provided by a combination sensor 196, as discussed further below. In some embodiments, gateway 188 provides information about an air intake pressure from combination sensor 196, an air intake temperature from combination sensor 196, and an air intake humidity from combination sensor 196. The inlet air humidity may be relative humidity or specific humidity. In some embodiments, gateway 188 is further configured to provide an exhaust NOx value from NOx sensor 192, an intake air mass flow rate, a NOx gain, a NOx offset, and a NOx pressure correlation that correlates a NOx pressure at exhaust stack 22 with boost pressure or another parameter that impacts NOx reduction, as feedback information.In some embodiments, the gateway 188 provides status information, such as status information related to one or more NOx sensor statuses, a humidity sensor status, and an operational status of one or more engine control modules or ECUs. In some embodiments, the data input circuit 128 receives data packets or raw data streams from the engine system 10, a generator, or other components of the engine system 10. The data input circuit 128 also provides or transmits information to the communication control interface 176, the HMI 180, the pump VFD 184, and the gateway 188.

[0031] In some embodiments, a liquid injection system for an engine system includes one or more processing circuits (e.g., implemented via processor 108) that include one or more memory devices (e.g., memory devices 112) associated therewith.The one or more memory devices are configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to receive temperature information indicative of a temperature within an air inlet; receive humidity information indicative of an inlet air humidity at the air inlet; receive pressure information indicative of an air pressure within the air inlet; determine a dew point temperature limit based on the temperature information, the humidity information, and the pressure information; determine an exhaust emission performance; determine a liquid flow rate based on the dew point temperature limit, the liquid flow rate allowing a reduction in the exhaust emission performance; and control at least one pump or valve to provide the liquid flow rate.

[0032] In some embodiments, the dew point circuit 132 is configured to determine a dew point temperature within the manifold 26 based on the information received from the analog input circuit 120, the digital input circuit 124, and the data input circuit 128.

[0033] In some embodiments, the pressure circuit 136 is configured to determine a dew point pressure within the manifold 26 based on the information received from the analog input circuit 120, the digital input circuit 124, and the data input circuit 128.

[0034] In some embodiments, the condensation limit circuit 140 is configured to determine a condensation limit at which condensation is predicted to form in the manifold 26 based on determinations from the dew point circuit 132 and the pressure circuit 136.

[0035] In some embodiments, dew point circuit 132, pressure circuit 136, and condensation limit circuit 140 communicate with each other. Pressure circuit 136 and dew point circuit 132 are each configured to determine pressure and dew point-related information. In some embodiments, dew point circuit 132, pressure circuit 136, and condensation limit circuit 140 are communicatively coupled to allow the determination of the following values: a. Amb_Sat_Vapor_Press (mbar) = a*EXP((b*Amb_Temp) / (Amb_Temp+c)) b. Amb_Vapor_Press (mbar) = Amb_Sat_Vapor_Press*Amb_Rel_Humidity / 100 c. Amb_Spec_Humidity (kg / kg) = d*Amb_Vapor_Press / (Amb_Press-(e*Amb_Vapor_Press)) d. IntakeMan_Spec_Humidity (kg / kg) = Amb_Spec_Humidity+(Water_Flow / Air_Flow) e. Intake_Man_Sat_Vapor_Press (mbar) = a*EXP((b*Intake_Man_Temp) / (Intake_Man_Te mp+c)) f. Intake_Man_Vapor_Press (mbar) = IntakeMan_Spec_Humidity*Intake_Man_Press / (d+e * Intake_Man_Spec_Humidity / 1000) g. Intake_Man_Rel_Humidity (%) =100* Intake_Man_Vapor_Press / Intake_Man_Sat_Va por_Press h. Dew_Temp (C) = (LN(Intake_Man_Vapor_Press / f)*c) / (b-LN(Intake_Man_Vapor_Press / f)),where Amb_Sat_Vapor_Press is the ambient saturated vapor pressure, Amb_Vapor_Press is the ambient vapor pressure, Amb_Temp is the ambient temperature, Amb_Rel_Humidity is the ambient relative humidity, Amb_Spec_Humidity is the ambient specific humidity, Amb_Press is the ambient pressure, Intakeman_Spec_humidity is the intake manifold specific humidity, Water_Flow is the water flow rate, Air_Flow is the air flow rate, Intake_Man_Sat_Vapor_Press is the intake manifold saturated vapor pressure, Intake_Man_Temp is the intake manifold temperature, Intake_Man_Vapor_Press is the vapor pressure in the intake manifold, IntakeMan_Spec_Humidity the specific humidity in the intake manifold, Intake_Man_Press the pressure in the intake manifold, Intake_Man_Rel_Humidity the relative humidity in the intake manifold and Dew_Temp the dew point temperature.In some embodiments, the scaling factors a, b, c, d, e, and f may vary depending on the various parameters and / or system requirements. In some embodiments, a is equal to 6.122, b is equal to 17.67, c is equal to 243.5, d is equal to 0.622, e is equal to 0.378, and f is equal to 6.112. Note that the exemplary embodiments described herein are not limited to any of the aforementioned values.

[0036] The limit circuit 144 is configured to determine a condensation margin limit. In some embodiments, the condensation margin limit is a user-defined, calibratable constant. For example, the condensation margin limit may be a temperature value (e.g., a temperature defined in degrees Celsius). The condensation margin limit may be calibrated upon installation of the engine system 10, determined at regular intervals (e.g., seasonally), or determined continuously. In some embodiments, the condensation margin limit is user-selectable and may be selected from a value of approximately five degrees Celsius (5°C) or approximately ten degrees Celsius (10°C). In some embodiments, the condensation margin limit also includes an associated pressure value, which may be determined similarly to the condensation margin limit temperature.In some embodiments, a condensation margin limit is determined based on a dew point temperature limit and output to the HMI 184.

[0037] In some embodiments, the condensation margin pressure is about 2 bar or about 4 bar. In some embodiments, the condensation margin limit may include other temperatures and pressures as desired for the particular engine system 10. The condensation margin limit may be determined based on the dew point temperature limit, and the fluid flow rate may be determined based on the dew point temperature limit and the condensation margin limit. In some embodiments, the limit circuit 144 is configured to determine the following parameters: a. Cond_Margin (C) = Intake_Man_Temp - Dew_Temp b. Dew_Temp_Max (C) = Intake_Man_Temp - Cond_Margin_Limit c. Intake_Man_Vapor_Press_Max (mbar) = f*EXP((Dew_Temp_Max*b) / (Dew_Temp_Max+c)) d. Intake_Man_Spec_Humidity_Max (kg / kg) =((d* Intake_Man_Vapor_Press_Max) / (Intak e_Man_Press-e* Intake_Press_Max)) e. Water_Flow_Max (kg / s) = (Intake_Man_Spec_Humidity_Max - Amb_Spec_Humidity) * Air_Flow, where Cond_Margin is the condensation margin limit, Dew_Temp_Max is the maximum dew point temperature, Intake_Man_Spec_Humidity Max is the maximum specific humidity in the intake manifold, Intake_Man_Vapor_Press_Max is the maximum vapor pressure in the intake manifold, and Water_Flow_Max is the maximum water flow rate. In some embodiments, the scaling factors b, c, d, e, and f may be the same numerical values ​​as those described above or different.

[0038] Output circuit 148 is configured to communicate with pump VFD 184, HMI 180, VFD fault reset 168, and solenoid valve 66 to control operation of liquid injection system 30 based on the determinations described above. In some embodiments, output circuit 148 provides the Water_Flow_Max value to solenoid valve 66 so that humidification is increased. This, in turn, results in reduced emissions output from engine system 10 while reducing or preventing the formation of condensate in manifold 26. Therefore, such control allows for, and may be implemented to reduce, emissions, including, but not limited to, NOx emissions.

[0039] As in Fig. 3, the controller 100 is configured to provide a process flow 200 that includes receiving an automatically generated NOx target in step 204 and a manual NOx target in step 208. In step 212, the controller 100 selects either the automatically generated NOx target or the manual NOx target and provides the selected target to a summation block 216. A summation / subtraction block 220 receives the dew point temperature and the maximum allowable dew point temperature (e.g., Dew_Temp_Max) and provides the processed parameters to a PI (proportional and integral) control step 224 that includes an anti-wind-up function (e.g., eliminating error accumulation as limits are approached). The outputs of the PI control step 224 are provided to the summation block 216.Thus, the liquid injection system is configured to operate in either a manual or an automatic mode, which either manually receives a NOx target value (e.g., through manual input by a user) or automatically provides and maintains closed-loop NOx control, including determining the liquid flow rate to achieve the NOx target value.

[0040] The summed parameters from the NOx target value and the PI control step 224 are provided to a summation / subtraction block 228 and processed using NOx feedback (e.g., from the NOx sensor 192). The summation / subtraction block 228 provides a current parameter list indicating the target NOx, the current dew point temperature, the current maximum allowable dew point temperature (e.g., Dew_Temp_Max), and the current NOx performance of the engine system 10. The output of the summation / subtraction block 228 is processed by a PI control step 232, which includes an anti-wind function, and the parameters are provided to a summation block 236.In some embodiments, the NOx target is received and used to determine one or more liquid flow rates based on the NOx target and a measured NOx performance of the liquid-injected engine system, or a condensation margin threshold that may be automatically determined based on the NOx target.

[0041] In step 240, the boost pressure is used to query a fluid flow forward table and return a target fluid flow for injection. The returned target fluid flow value is provided to summation block 236. Summing block 236 then determines the water control parameters based on the received target fluid flow value and the parameters provided by PI control step 232. Process flow 200 includes two separate PI control steps 224 and 232, which provide separate PI controls for automatic and manual modes of operation and allow separate boosts. In some embodiments, a single PI control may be implemented.

[0042] In step 248, a flow command upper limit is determined based at least in part on the boost pressure. The flow command upper limit is provided to a minimum function 244, which serves to limit the target fluid flow rate obtained from summation block 236. Thus, the fluid flow rate is limited by a flow command upper limit.

[0043] In some embodiments, a NOx target value is received and used to determine a fluid flow rate to achieve the target. For example, minimum function 244 outputs a final fluid flow rate value that should be injected into engine 10 to achieve the NOx target value. In step 252, the final fluid flow rate value is used to query a pump speed / flow table, and a flow command for the pump VFD is output to pump VFD 184.

[0044] In some embodiments, one or more of the lookup tables discussed in process flow 200 may be replaced by machine learning or AI. In some embodiments, various parameters may be used to determine the final fluid flow value.

[0045] In some embodiments, a method for controlling a liquid injection system for an engine is provided. The method includes receiving temperature information indicative of a temperature within an air intake; receiving humidity information indicative of an intake air humidity at the air intake; receiving pressure information indicative of an air pressure within the air intake; determining a dew point temperature limit based on the temperature information, the humidity information, and the pressure information; determining an exhaust emission performance; determining a liquid flow rate based on the dew point temperature limit, the liquid flow rate allowing a reduction in the exhaust emission performance; and controlling at least one pump or water solenoid valve to provide the liquid flow rate.These and other aspects are discussed below with reference to . Fig. 4 described.

[0046] As in Fig. 4, a method 300 for determining control outputs of the controller 100 includes receiving inputs of the controller 100 in step 304. The inputs include one or more of the following: an engine load limit determination that the kW output of the engine system 10 is above a threshold (e.g., about 50%) in step 308, an engine speed limit determination that a revolutions per minute (RPM) value is greater than a threshold (e.g., about 90% of a rated engine speed) in step 312, a determination that a coolant temperature is greater than a lower limit in step 316, a determination that the coolant temperature is less than an upper limit in step 320, a determination that a NOx dew point has been reached in step 324, a determination that a low water level is off in step 328, a determination that a communication error is off in Step 332, a determinationthat an injected water pressure is below an upper limit in step 336, a determination that an exhaust stack temperature is greater than a lower limit in step 340, a determination that the exhaust stack temperature is below an upper limit in step 344, a determination that the injected water pressure is greater than a lower limit in step 348, a determination that the controller 100 is in an automatic mode in step 352, a determination that the controller 100 is in a manual mode in step 356, and a determination whether an automatic mode or a manual mode is selected in step 360.

[0047] In some embodiments, in manual mode, the liquid injection system 30 turns on the water pump 46 and maintains closed-loop NOx control at the user-specified target value when the liquid injection conditions are met.

[0048] The processors 108 are configured to prevent the pump or valve from providing the fluid flow rate if one or more fluid injection conditions are not met and to allow the pump or valve to provide the fluid flow rate if one or more fluid injection conditions are met.

[0049] If the liquid injection conditions are not met, the water return solenoid valve 66 is placed in a return position, and the water pump 46 is turned off until the liquid injection conditions are met again. Liquid injection is limited to a threshold (e.g., a maximum) determined by the condensation margin calculation, regardless of user request. In automatic mode, the liquid injection system 30 turns on the water pump 46 and maintains closed-loop NOx control at the maximum value determined by the condensation margin calculation when the liquid injection conditions are met.If the fluid injection conditions are not met, the water return solenoid valve 66 is moved to the return position and the water pump 46 is turned off until the fluid injection limits are met. Controller 100 processes inputs 308-360 in step 304 and determines the control parameters in step 364.

[0050] In some embodiments, inputs 308-360 are used to determine the conditions for liquid injection. Generally, such conditions indicate when liquid injection can be performed without significant condensation (among other undesirable phenomena). In some embodiments, the conditions include: a) the kW load is greater than a calibratable threshold in step 308, b) the engine speed is greater than a calibratable threshold in step 312, and c) the NOx sensor dew point reached signal is equal to 1. Each condition may include a calibratable hysteresis to reduce or prevent noise (e.g., signal chatter) near the thresholds.Thus, the method includes preventing the water pump and the water solenoid valve from providing the liquid flow rate when the liquid injection conditions are not met and allowing the water pump and the water solenoid valve to provide the liquid flow rate when the liquid injection conditions are met, wherein the liquid injection conditions include an engine load greater than an engine load limit, an engine speed greater than an engine speed limit, and a NOx sensor dew point reached signal is received from a NOx sensor.

[0051] In some embodiments, storage device 112 is configured to store instructions that, when executed by one or more processors, cause the one or more processors to receive dew point temperature information indicative of a dew point temperature at a manifold; receive dew point pressure information indicative of a dew point pressure within the manifold; and determine the dew point temperature limit based on the temperature information, the humidity information, the pressure information, the dew point temperature information, and the dew point pressure information.

[0052] As in Fig. 5, the method 300 also includes receiving humidity and temperature sensor inputs in step 368. The method 300 further includes determining a dew point temperature in step 372. In step 376, an intake manifold temperature is received from the controller 100. In step 380, a condensation margin limit is received from the controller 100. As described above, the condensation margin limit is a calibratable value that may be automatically generated, user-selected, or determined using lookup tables or machine learning techniques. In some embodiments, the condensation margin limit is determined based on information entered by a user. In step 384, a subtraction function is implemented to process the received intake manifold temperature and the condensation margin limit.

[0053] In step 388, a PI control function processes the output of the subtraction function of step 384 and the outputs of the dew point calculator of step 372. In step 392, a condensation margin calculator determines the condensation margin temperature. In some embodiments, the condensation margin temperature corresponds to the limit temperature for operation of the liquid injection system 30. The condensation margin calculator is configured to determine the condensation margin temperature based on the intake manifold pressure and the outputs of the dew point temperature calculation of step 372. In step 396, the condensation margin temperature is displayed on the HMI 180.

[0054] As in Fig. 6, the method 300 also includes receiving boost pressure information in step 400 and converting the boost pressure information into flow rate information in step 404. In step 408, the flow rate information is provided to an adder function. In step 412, a flow limit (e.g., a maximum flow limit) is determined based on the boost pressure information. In step 416, a flow-to-speed converter receives information from the adder function from step 408 and the maximum flow limit from step 412 and outputs a rotational speed (RPM) value. In some embodiments, pump speed information is output to the HMI 180.

[0055] In step 420, NOx information from NOx sensor 192 is provided to controller 100. In step 424, it is determined whether a NOx dew point has been reached. In step 428, the measured NOx value is compensated for pressure and calibration errors. In step 432, the NOx information is displayed on HMI 180.

[0056] In step 436, the automatic settings for the NOx content are received and then in step 440, in addition to the outputs of the PI function block from step 388, Fig. 5 of an adder function. In some embodiments, the automatic NOx level settings may be predefined, e.g., hard-coded. The combined NOx level automatic settings and PI function outputs are provided to a PI function in step 444. The compensated NOx level outputs from step 428 are also provided to the PI function in step 444. The PI function outputs are then provided to an OR function in step 448.

[0057] In step 452, the manual settings of the NOx value are received via user input on the HMI 180 and then in step 546, in addition to the outputs of the PI function block from step 388, Fig. 5 to an adder function. The combined NOx level automatic settings and PI function outputs are provided to a PI function in step 460. The compensated NOx level outputs from step 428 are also provided to the PI function in step 460. The PI function outputs are then provided to an OR function in step 448.

[0058] The NOx parameters and information selected by the OR function in step 448 are provided to the addition function in step 408 and influence the determination of the speed in step 416.

[0059] In step 464, the control parameters from step 364 are then Fig. 4 and processed for injection in the controller. If the control parameters are not met in step 468, commands are sent to the solenoid valve 66 in step 472 to close and stop liquid injection. For example, if the control parameters are not met, it is assumed that the conditions for water injection are not met. Such conditions (i.e., conditions where the control parameters are not met) are an indication that water injection may result in condensation in the manifold. If the control parameters are not met in step 468, the pump VFD 184 is controlled not to rotate the motor 50, so no pump pressure is provided.

[0060] If the control parameters in step 480 are met (e.g., if the conditions for liquid injection are met and do not result in condensation in the manifold), commands are sent to start the VFD 184 pump. In step 484, the VFD 184 is commanded to start the pump 54 and provide water pressure. In step 486, the solenoid valve 66 is commanded to open and provide liquid injection.

[0061] In step 488, the speed output from step 416 is provided to the pump VFD 184 to control the pump pressure and speed. In step 492, the actual motor speed (RPM) and current are displayed on the HMI 180. The HMI 180 may have a display interface, such as a touchscreen, monitor, or other device with a display screen.

[0062] The systems and methods discussed above provide for a determination of a dew point temperature limit that serves as a threshold temperature and pressure at which condensation is likely to form in an engine intake manifold. The systems and methods determine a condensation limit below which condensation could occur in the manifold (e.g., 10°C). A liquid injection system is then controlled to minimize NOx emissions while maintaining conditions outside the condensation limit. This allows the systems and methods to significantly improve the engine system's ability to reduce NOx emissions. Furthermore, such a reduction in NOx emissions is achieved while simultaneously preventing the formation of condensate in the manifold, thereby reducing the adverse effects of liquid condensation.

[0063] It should be noted that the term "exemplary" and variations thereof, as used herein to describe various embodiments, is intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such terms are not intended to imply that such embodiments are necessarily exceptional or superlative examples).

[0064] The term "coupled" and variations thereof, as used herein, means the connection of two elements directly or indirectly to one another. Such a connection may be stationary (e.g., permanent or fixed) or movable (e.g., removable or detachable). Such a connection may be achieved by coupling the two elements directly to one another, by coupling the two elements using one or more separate intermediate elements, or by coupling the two elements using an intermediate element that is formed as a single unitary body with one of the two elements. When "coupled" or variations thereof are modified by an additional term (e.g., directly coupled), the general definition of "coupled" provided above is modified by the unambiguous meaning of the additional term (e.g.,"Directly coupled" means the connection of two links without a separate intermediate link), which results in a narrower definition than the general definition of "coupled" provided above. Such coupling can be mechanical, electrical, or fluidic. For example, a circuit A "coupled" to a circuit B can mean that circuit A communicates directly with circuit B (i.e., without an intermediate link) or communicates indirectly with circuit B (e.g., via one or more intermediate links).

[0065] References to the positions of elements (e.g., "top," "bottom," "upper," "lower") are used herein merely to describe the orientation of various elements in the figures. It should be noted that the orientation of various elements may vary in other exemplary embodiments, and such variations are intended to be encompassed by the present disclosure.

[0066] Although in Fig. 2, various circuits with particular functionality are illustrated, the controller 100 may include any number of circuits to perform the functions described herein. For example, the activities and functions of the circuits of the controller 116 may be combined into multiple circuits or into a single circuit. Additional circuits with additional functions may also be included. In addition, the controller 100 may also control other activities beyond the scope of the present disclosure.

[0067] As mentioned above and in one configuration, the “circuitry” may be embodied in a machine-readable medium for execution by various types of processors, such as the processor 108 of Fig.2. An identified circuit of executable code may, for example, comprise one or more physical or logical blocks of computer instructions, which may be organized, for example, as an object, procedure, or function. However, the executable files of an identified circuit need not be physically located in one place, but may consist of various instructions stored in different locations which, when logically linked together, form the circuit and accomplish the circuit's stated purpose. A circuit of computer-readable program code may consist of a single instruction or many instructions, and may even be distributed across several different code segments, different programs, and multiple storage devices.Similarly, operational data may be identified and represented within circuits, and may be embodied in any suitable form and organized in any suitable type of data structure. The operational data may be collected as a single data set or distributed across various locations, including various storage devices, and may exist, at least in part, solely as electronic signals in a system or network.

[0068] While the term "processor" is briefly defined above, the terms "processor" and "processing circuitry" should be interpreted broadly. As previously mentioned, the "processor" may be implemented as one or more general-purpose processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), or other suitable electronic data processing components structured to execute instructions provided by memory. The one or more processors may take the form of a single-core processor, a multi-core processor (e.g., a dual-core processor, a triple-core processor, a quad-core processor, etc.), a microprocessor, etc. In some embodiments, the one or more processors may be external to the system; for example, the one or more processors may be a remote processor (e.g., a cloud-based processor).Alternatively or additionally, the one or more processors may be internal and / or local to the system. In this regard, a particular circuit or its components may be located locally (e.g., as part of a local server, a local computer system, etc.) or remotely (e.g., as part of a remote server such as a cloud-based server). For this purpose, a "circuit," as described herein, may include components distributed across one or more locations.

[0069] Embodiments within the scope of the present disclosure include program products comprising machine-readable media on which machine-executable instructions or data structures are stored. Such machine-readable media may be any available media accessible by a general-purpose or special-purpose computer or other machine having a processor. Such machine-readable media may include, for example, RAM, ROM, EPROM, EEPROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of machine-executable instructions or data structures and that can be accessed by a general-purpose or special-purpose computer or other machine having a processor. Combinations of the above media also fall within the scope of machine-readable media.

[0070] Although a particular sequence of method steps is illustrated in the figures and descriptions, the order of these steps may vary from the illustrations and descriptions unless otherwise stated above. Also, two or more steps may be performed simultaneously or partially simultaneously unless otherwise stated above. Such variations may depend, for example, on the software and hardware systems chosen and on the designer's choices. All such variations are within the scope of the disclosure. Likewise, software implementations of the described methods may be carried out using standard programming techniques with rule-based logic and other logic to perform the various connecting steps, processing steps, comparing steps, and decision steps.

[0071] The terms "about" or "approximately" before a numerical value mean the value plus or minus a range of 10% or 15% of the value, as used herein. As will be understood by one of skill in the art, all ranges recited herein also include all possible subranges and combinations of subranges thereof, etc. As will be understood by one of skill in the art, all expressions such as "up to," "at least," "greater than," "less than," and the like include the recited number and refer to ranges that can subsequently be subdivided into subranges as described above. Finally, as one of skill in the art will understand, a range includes each individual element.

[0072] It is important to note that the structure and arrangement of the engine system 10 as shown in the various exemplary embodiments are illustrative only. Furthermore, any element disclosed in one embodiment may be incorporated or used in any other embodiment disclosed herein. Although only one example of an element from one embodiment that may be incorporated or used in another embodiment has been described above, it should be understood that other elements of the various embodiments may be incorporated or used in any of the other embodiments disclosed herein.

Claims

[1] Liquid injection system for an engine system, consisting of: one or more processing circuits comprising one or more memory devices coupled to one or more processors, the one or more memory devices configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to receive temperature information indicating a temperature in an air intake; Receive humidity information indicating the humidity at the air inlet; to receive pressure information indicating air pressure in the air intake; determine a dew point temperature limit based on the temperature information, the humidity information and the pressure information; to determine an exhaust emission performance; to determine a liquid flow rate based on the dew point temperature limit, the liquid flow rate allowing a reduction in exhaust emission performance; and to control at least one pump or valve to provide the fluid flow. [2] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to achieve a NOx target; and to determine the liquid flow rate to achieve the NOx target. [3] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: prevent the pump and / or valve from providing the fluid flow if one or more fluid injection conditions are not met; and allow the pump and / or valve to provide fluid flow when one or more fluid injection conditions are met. [4] A liquid injection system according to claim 3, wherein the one or more liquid injection conditions comprise: an engine load that exceeds an engine load limit; an engine speed that is greater than an engine speed limit; and Receiving a NOx sensor dew point reaching signal. [5] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: To determine a limit for condensation margin based on the dew point temperature limit; and to determine the liquid flow rate based on the dew point temperature limit and the condensation margin limit. [6] The liquid injection system of claim 5, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to determine the condensation margin limit based on information entered by a user. [7] The liquid injection system of claim 5, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to achieve a NOx target; and to automatically determine the condensation margin limit based on the NOx target. [8] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: receive manifold temperature information indicating a manifold temperature at a manifold; receive manifold pressure information indicating a manifold pressure within the manifold; and to determine the dew point temperature limit based on the temperature information, the humidity information, the pressure information, the manifold temperature information and the manifold pressure information. [9] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to control the pump by sending control commands to a variable frequency drive to provide fluid flow. [10] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: To determine a limit for condensation margin based on the dew point temperature limit; and to output the condensation range limit value to a human-machine interface. [11] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: To output information about the pump motor speed per minute to a human-machine interface. [12] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to limit the fluid flow rate by setting an upper limit of a flow instruction. [13] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: receive the temperature information, the humidity information, and the pressure information from a combination sensor of the engine system, the combination sensor being configured to sense the relative humidity, the temperature, and the pressure. [14] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: operate the liquid injection system in an automatic mode that automatically provides a NOx target; and maintain a closed NOx control loop that determines the fluid flow rate to achieve the NOx target. [15] The liquid injection system of claim 1, wherein the one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: to operate the liquid injection system in a manual mode that receives a NOx target manually entered by a user; and maintain a closed NOx control loop that determines the fluid flow rate to achieve the NOx target. [16] Liquid injection engine system comprising: a water distributor; a water tank; a water pump fluidly coupled to the water tank; a water solenoid valve that selectively connects a water injection nozzle to the water pump; and a controller designed to: determine a dew point temperature limit based on temperature, pressure and humidity information from the water distributor; to determine a limit for condensation margin based on the dew point temperature limit; to determine a liquid flow rate based on the dew point temperature limit and the condensation margin limit; and to control the water pump and the water solenoid valve to provide the fluid flow to the water injector. [17] A liquid injection engine system according to claim 16, wherein the controller is further configured to: receives a NOx target; and the liquid flow rate is determined based on the NOx target and a measured NOx performance of the liquid-injected engine system. [18] A method of controlling a liquid injection system for an engine, comprising: Receiving temperature information indicating a temperature in an air inlet; Receiving humidity information indicating the humidity at the air inlet; Receiving pressure information indicating air pressure in the air inlet; Determining a dew point temperature limit based on the temperature information, the humidity information, and the pressure information; Determination of exhaust emission performance; Determining a liquid flow rate based on the dew point temperature limit, the liquid flow rate allowing a reduction in exhaust emission performance; and Control of at least one pump or water solenoid valve to provide fluid flow. [19] The method according to claim 18 further comprises: Preventing the water pump and water solenoid valve from providing fluid flow when fluid injection conditions are not met; and Allow the water pump and water solenoid valve to provide fluid flow when fluid injection conditions are met, where the conditions for liquid injection include: an engine load that exceeds an engine load limit; an engine speed that is greater than an engine speed limit; and Receiving a NOx sensor dew point reaching signal from a NOx sensor. [20] The method according to claim 19 further comprises displaying at least information from the NOx sensor on a human-machine interface.

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