WO2016041339A1

WO2016041339A1 - Liquid jet metering unit and control method

Info

Publication number: WO2016041339A1
Application number: PCT/CN2015/076020
Authority: WO
Inventors: 郗大光; 张平; 杨延相
Original assignee: 浙江福爱电子有限公司
Priority date: 2014-09-19
Filing date: 2015-04-08
Publication date: 2016-03-24
Also published as: CN105484833A; CN105484833B; DE112015004242T5

Abstract

Disclosed are a liquid jet metering unit and a control method thereof, wherein the liquid jet metering unit comprises a jet unit and a metering controller (13), the jet unit comprises a solenoid device (18), a plunger pump (8) and a nozzle (23), the solenoid device (18) comprises a coil (19), a magnetic yoke (20) and a magnetic resistor, the plunger pump (8) comprises a plunger (12) and a sleeve (11), the plunger (12) and the sleeve (11) are matched to form a pressure delivery volume (9), the pressure delivery volume (9) is connected to a liquid inlet valve (16) and a liquid outlet valve (17), the metering controller (13) supplies a driving signal to the solenoid device (18), and the metering controller (13) comprises a detecting device capable of detecting state parameters of the solenoid device (18). The control method comprises an algorithm of using the state parameters to predict the effective output power of the solenoid device (18), and further comprises a method of taking the effective output power of the solenoid device (18) as a variable and performing closed loop control on the flow of the liquid jet metering unit, wherein the effective output power of the solenoid device (18) means directly applying a pressure to liquid in the pressure delivery volume (9) and forming energy required in jetting. The metering unit and its control method are widely applied, and have high control accuracy.

Description

Liquid injection metering unit and control method

Technical field

The invention belongs to the field of liquid metering technology, in particular to an engine related liquid injection metering technology, in particular to an engine fuel injection device, an engine exhaust gas purification NOx selective catalytic reduction (SCR) system, and a diesel engine exhaust particulate filter collector (DPF). ) fuel injection regeneration system and its control technology.

Background technique

Liquid jet metering has a wide range of applications in the chemical, medical and power machinery sectors, especially in the core technologies of internal combustion power.

As environmental issues become more prominent, energy conservation and emission reduction have become the most important themes in the engine industry. Many countries around the world are constantly introducing a series of engine and vehicle emission standards. For this, internal combustion engine-powered vehicles require better combustion control. And install an aftertreatment system to meet increasingly stringent emission requirements. For example, engines including spark-ignition small engines use electronically controlled fuel injection technology and exhaust three-way catalytic processing technology like automobile engines; diesel engines or lean-burning direct-injection gasoline engines to reduce harmful emissions in exhaust gas. Contaminants, for NOx pollutants, use NOx selective catalytic reduction (SCR=Selective Catalytic Reduction) technology for catalytic reduction in oxygen-rich environments; for particulate matter emissions from diesel engines, use diesel particulate filter traps (DPF=Diesel) Particulate Filter) technology.

All of these technologies involve the problem of liquid injection metering control. For gasoline injection technology, injection metering is required and feedback is required to control the amount of gasoline injection. For DPF regeneration technology, the amount of diesel fuel injected into the exhaust pipe upstream of the DPF is required to be injected; For the SCR technology, it is necessary to meter the NOx selective reducing agent upstream of the SCR catalyst, for example, a 32.5% by weight aqueous urea solution (also called diesel exhaust treatment solution DEF = Diesel Exhaust Fluid, or Add Blue Liquid AdBlue).

After entering the engine exhaust pipe, the DEF is decomposed into ammonia by the exhaust gas, mixed with the exhaust gas, and then enters the SCR catalytic converter. Under the action of the catalyst, the ammonia gas undergoes a catalytic reduction reaction with NOx in the engine exhaust gas to decompose NOx into harmless N2 and H2O. If the amount of DEF injection does not match the NOx content in the exhaust gas, then either NOx cannot be fully reduced and decomposed, the amount of emissions is increased, or a large amount of ammonia gas is discharged to the atmosphere, causing secondary pollution. Therefore, the SCR system necessarily requires a highly accurate SCR metering injection device.

For the SCR injection metering system, since the urea aqueous solution has electrical conductivity, the conventional injection metering system using a DC rotary electric pump as a power source cannot sneak into the working liquid. Therefore, most of the prior art uses an external diaphragm driven by a DC motor. The pump is the power source. The structure of this system is complicated. In addition to the reliability, it is also greatly affected by the environment. Especially in the low temperature environment, it requires complicated ice-melting auxiliary devices, and the after-sales service maintenance is also difficult.

In the engine field, specific techniques related to liquid injection metering include, but are not limited to, engine electronic fuel injection systems, including in-cylinder direct injection (GDI) and out-of-cylinder injection (MPI), and engine exhaust purification of nitrogen oxide selective catalytic reduction (SCR). ) Urea aqueous injection system, diesel exhaust particulate filtering (DPF) regenerative fuel injection system.

U.S. Patent No. 20090301067A1 discloses a DEF injection metering device in which a metering injection device is a solenoid-driven plunger pump nozzle mounted on an exhaust pipe and requires a low pressure pump to be added thereto. Working fluid is supplied from the DEF reservoir and requires cooling to work properly.

DPF regenerative fuel injection, in order to improve combustion efficiency to obtain the highest DPF temperature with minimum fuel consumption to achieve the purpose of burning off collected soot and other particulate matter, the injected diesel must be atomized well. However, most of the prior art uses low pressure injection technology. For example, the technical solution disclosed in the U.S. Patent (Publication No.: US2007/0033927) is borrowed. The basic principle of the gasoline inlet injection system and the structure of the fuel, the injection pressure is relatively low.

In general, engine-related injection metering techniques can be divided into three different types: mouth end control, pump end control, and nozzle-pump end mixing control. Among them, mouth end control has been widely used in fuel port injection system, nozzle-pump hybrid control has been widely used in fuel tank direct injection system, pump end control is applied to in-cylinder fuel direct injection, single cylinder gasoline engine fuel Jet and SCR systems, etc.

It is difficult in the prior art to unify the above applications to one type of actuator and metering method. One of the fundamental reasons is that the universally applied rotary low pressure gasoline pump cannot handle conductive media such as aqueous urea solution. While another solenoid plunger pump can handle conductive, non-conductive liquids, there are problems with accurate metering.

The solenoid plunger pump can be subdivided into two different configurations, a plunger-sleeve pump with plunger movement and a sleeve-plunger pump with sleeve movement. With regard to a plunger-sleeve pump for pumping fuel, US Patent No. 2,030, 155, 444 A1 discloses a metering control method, that is, a method of predicting a fuel injection amount by predicting the position of a plunger. However, since the fuel, especially gasoline, is highly volatile, the fluid entering the plunger sleeve usually contains a certain amount of steam or air, and there is no one-to-one correspondence between the amount of fuel injected and the position of the plunger. In addition, predicting the displacement of the plunger is as difficult as predicting the amount of fuel injection, and there are certain difficulties in implementation.

Therefore, regarding the solenoid plunger pump, whether it is a plunger-sleeve pump or a sleeve-plunger pump, it is very valuable to propose a simple structure and application method capable of simultaneously meeting a plurality of targets, and a unified measurement method. A job.

Summary of the invention

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide an actuator scheme capable of achieving pump end control, a versatile and compact structure, and a unified control metering method. These technical solutions and control methods can be widely applied to the design of liquid injection systems in diesel or gasoline engine exhaust gas purification SCR and DPF systems, and the design of spark ignition engine fuel injection systems, including inlet and in-cylinder direct injection systems. .

In order to achieve the above object, the present invention adopts the following technical solution, that is, a liquid injection metering unit and a control method, including an injection unit and a metering controller, the injection unit including a solenoid device, and a a plunger pump and a nozzle, the solenoid device comprising a coil, a yoke, a magnetoresistance and an armature, wherein the yoke and the armature are made of a magnetically permeable material, and the magnetic resistance is made of a non-magnetically permeable material, the plunger The pump comprises a plunger and a sleeve, the plunger and the sleeve cooperate to form a pressure delivery volume, the pressure delivery volume is connected to the inlet valve and the outlet valve, and the liquid is fed from the inlet valve into the pressure delivery volume from the outlet valve, the metering control The device provides a driving signal for the solenoid device, and the metering controller includes a monitoring device that can monitor the state parameters of the solenoid device, including an algorithm for predicting the effective output of the solenoid device by using the state parameter, including the effective output of the solenoid device. The work is a method of closed-loop control of the flow rate of the liquid injection metering unit. The efficient output work of the solenoid device refers to directly pressurizing the liquid in the pressure feed volume and forming the energy required for the injection.

For the control of the solenoid device, the most common method is to adopt the PWM simple driving method. This method does not feedback correction of the execution result of the solenoid, which may result in inconsistency between the target and the result, and often cannot be completely covered because of the liquid state. Factors such as changes (such as the occurrence of two-phase flow, etc.), changes in drive voltage, and changes in solenoid resistance have an effect on the execution results.

For the above liquid jet metering unit, an alternative solution is a sleeve-plunger pump structure, that is, including a return spring, the sleeve reciprocating under the driving of the solenoid device and the return spring, resulting in pressure feed Alternate changes in volume.

For the above liquid jet metering unit, another alternative is a plunger-sleeve pump structure, that is, including a return spring, the plunger reciprocating under the driving of the solenoid device and the return spring, resulting in pressure The change in the size of the delivery volume.

For the plunger-sleeve pump structure, a further refinement is that the plunger includes an armature, the armature is substantially a cylinder, and the armature includes through holes extending through the end faces. The through hole may have a certain taper, and the tapered hole expands toward the liquid pressure feeding direction for realizing the directional flow of the liquid in the inner space to cool the liquid injection metering unit and improve the stability of its operation.

The return spring in the above solution can be replaced by another solenoid device to provide the force required for the sleeve or plunger to return.

In the above solution, a high pressure pipe may be included between the discharge passage and the nozzle, and the high pressure pipe is made of a metal or polymer material, and may be a rigid pipe that is shaped or a flexible pipe that is bendable. In addition, the liquid from the reservoir needs to pass through a filter to enter the internal space of the liquid injection metering unit.

An alternative solution is to include a gas-liquid mixing chamber in which the liquid is first injected into the gas-liquid mixing chamber, and the liquid is mixed with the gas and then injected into the exhaust pipe of the engine through an injector. The ejector may be a simple orifice nozzle or a swirl nozzle without a nozzle valve. This solution can achieve the following different objectives for different applications: one is to facilitate liquid atomization and increase the oxygen content of the exhaust pipe, the second is to avoid blockage and damage of the liquid pipeline to the conveying pipeline, and the third is to avoid the solvent. For example, when the water evaporates, the crystals of the spray liquid such as the urea aqueous solution are precipitated to block the pipeline, and the fourth is to prevent the clogging of the nozzle by the coke component in the liquid.

With the above scheme, when the engine does not need to eject liquid, the high pressure gas continues to supply air to sweep off the residual liquid from the vapor-liquid mixing chamber to the injector.

Another injection scheme applied to the engine exhaust aftertreatment system is that the liquid is directly injected into the engine exhaust pipe from the nozzle through the high pressure pipe. If the injected liquid is DEF, in addition to the DEF required to reduce NOx emissions, a small amount of DEF may be injected to prevent the nozzle from overheating or clogging. In order to prevent the high pressure pipe from freezing, it is necessary to arrange the ice melting device along the high pressure pipe, for example, by electric heating or engine cooling water heating.

To predict the effective output of the solenoid device by means of energy balance, it is necessary to estimate the total energy output by the metering controller, estimate the power consumption of the solenoid resistor, and estimate the energy storage of the solenoid device. Thus, the effective output of the solenoid = the total energy output of the metering controller - the solenoid resistance power consumption - the solenoid device inductive energy storage - the flow resistance power consumption - the return spring energy storage.

The state parameters of the solenoid device can be selected to be the current through the coil and the voltage across the coil.

Specifically, the product of the current and voltage of the monitored coil is integrated with time to approximate the total energy output of the metering controller, and the product of the square of the current of the detected coil and the solenoid resistance is used to approximate the coil resistance with time integral. Power consumption, using the monitored solenoid current to calculate the energy storage of the solenoid device. The flow resistance power consumption of the liquid and the energy storage of the return spring can be simply handled as follows: a linear relationship with the injection amount after the start of the injection. The above energy balance relationship can be expressed in the following mathematical way:

Assume,

Q-liquid injection amount;

Wn is the effective output work of the solenoid device;

The total energy input by Et to the solenoid device, Et0 is Et corresponding to the start of injection;

Er is the coil resistor energy consumption, and Er0 is the Er corresponding to the start of the injection;

Ein is the energy storage of the current solenoid device, and Ein0 is the Ein corresponding to the start of the injection;

Wr is the fluid resistance power consumption, and Wr0 is the Wr corresponding to the start of the injection;

Es is the energy storage of the return spring, Es0 is the energy storage of the return spring when starting the injection, and Esi is the pre-storage energy of the return spring when the coil is energized.

Then,

Wn=η·Q, η is the proportional coefficient between the effective output power and the injection amount.

Wn=Et-Er-Ein-Wr-(Es-Esi),

Et0=Er0+Ein0+Wr0+(Es0-Esi),

Or, Wn=(Et-Et0)-(Er-Er0)-(Ein-Ein0)-(Wr-Wr0)-(Es-Es0),

The specific expressions are:

Et=int(Id·Vd),

Er=int(Id ² ·r), r is the resistance of the coil,

Ein=L·Id ² /2, L is the inductance of the solenoid device,

Es=K·X ² /2, K is the spring constant of the return spring, and X is the compression amount of the spring.

(Wr-Wr0)=ζ·Q, ζ is a proportional coefficient,

Above, int represents the integral of time after the coil is energized;

therefore,

Q=[(Et-Et0)-(Er-Er0)-(Ein-Ein0)-(Es-Es0)]/α, α=η+ζ.

The variables included in the right side of the above formula are the state parameters of the solenoid device that can be monitored in real time: Id, Vd, constant: r, K, L, and the undetermined coefficient α. Among them, α can be calibrated by the actual measurement of flow. If the above physical relationship is relatively complete, α should be a constant; L can be calibrated by actual measurement of multi-point flow by theoretical calculation or as undetermined coefficient.

According to practice, it is reasonable to treat the energy storage (Es-Es0) of the return spring to be proportional to Q, so that the formula for the injection quantity does not include the energy storage of the return spring.

Further, Er-Er0 and Ein-Ein0 can be simply processed separately or simultaneously to be proportional to the injection amount Q, so that the expression of the injection amount can be greatly simplified, that is,

Q=(Et-Et0)/μ, μ is a pending coefficient that can be calibrated by flow measurement. This simplified model is equivalent to fitting the injection flow rate by multiplying the product of current and voltage over time.

Above, regarding the fluid resistance power consumption of the liquid, a further refined model can also be used for approximation. For example, the resistance is proportional to the square of the relative flow velocity, and the undetermined coefficient involved can be performed by the multi-point flow test of the liquid jet metering unit. Calibration.

U.S. Patent No. 7,727,038 B2 discloses a more simplified method for directly fitting the injection flow rate with the integration of current versus time. The factors of the supply voltage variation are not considered here, especially the transient fluctuation of the voltage for the effective output of the solenoid device. influences.

Another option is: the time T3 required for the electromotive force to drop to the reference voltage after the coil is de-energized, defined as the state parameter of the solenoid device, and the effective output of the solenoid device has a good correspondence with T3, a simplified The correspondence is to treat T3 and the solenoid effective output work as a linear relationship.

If the flow rate of the liquid ejected per unit time is the control target, an alternative control mode is: keeping the injection quantity of the single pulse of the liquid injection metering unit unchanged, that is, fixing the effective output work of each pulse solenoid device, by changing The liquid injection metering unit operates at a frequency to achieve the goal. Another control mode is to keep the working frequency of the liquid injection metering unit constant, and achieve the goal by changing the effective output of the solenoid device. It is also possible to combine the two in such a way that the objective is achieved by varying the operating frequency of the liquid jet metering unit and the effective output of the solenoid device.

A method of measuring the level of liquid in a liquid storage tank is included: measuring the liquid level is indirectly measured by measuring the fluid resistance of the liquid to the moving parts of the plunger pump. The resistance of the liquid can be obtained by detecting the characteristics of the above solenoid state parameters.

The liquid injection metering unit and the control method thereof provided by the present invention can be applied to, but not limited to, the following three aspects, namely, a fuel injection metering device of an engine management system, a urea aqueous solution injection metering device for an engine aftertreatment SCR system, and an engine aftertreatment DPF. Active regenerative fuel injection metering device for the system. Other applications include engine fuel additive metered injection mixing devices, engine low temperature start assisted combustion injection devices, and the like.

The plunger pump of the present invention can be placed either inside the reservoir or outside the reservoir. For the SCR injection system, when the plunger pump is placed inside the reservoir, the device required for winter ice melting can be reduced. When the liquid injection metering unit is placed outside the reservoir, the filter can be integrated with the liquid injection metering unit, and the liquid can be passed from the bottom of the reservoir through the supply line to the filter by gravity or an additional low pressure pump. And then enter the liquid injection metering unit, and the liquid return port can reach the top of the liquid storage tank through the external liquid return pipe.

For the various schemes of the above liquid ejecting unit and the control method, a more practical application scheme is: a metering module comprising a bracket formed by a melting ice tube, the spraying unit is fixed at one end of the bracket, and the controller is fixed on the bracket The other end. This solution is particularly suitable for an injection system constituting an aqueous solution of SCR urea, which can be placed vertically or horizontally in a liquid storage tank, wherein one end of the fixed controller is fixed on the liquid storage tank, and the controller is exposed to the liquid storage tank One end of the fixed spray unit is located at the bottom of the liquid storage tank.

The present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

DRAWINGS

1 is a logic structural diagram of a liquid jet metering unit including a sleeve-plunger pump provided by the present invention.

2 is a logic structural diagram of a liquid jet metering unit including a plunger-sleeve pump provided by the present invention.

Figure 3a is an embodiment of a liquid jet metering unit including a sleeve-plunger pump provided by the present invention.

Figure 3b is an embodiment of a liquid jet metering unit including a plunger-sleeve pump provided by the present invention.

Figure 4 is a schematic diagram showing the measurement of the state parameter of the solenoid device of the liquid jet metering unit provided by the present invention.

Fig. 5a shows a solenoid device state parameter voltage measuring circuit of the liquid jet metering unit provided by the present invention.

Fig. 5b shows a solenoid device state parameter current measuring circuit of the liquid jet metering unit provided by the present invention.

6 is a logic diagram of active flow closed loop control of a liquid injection metering unit provided by the present invention.

Figure 7a is a physical definition of the solenoid device state parameter T3 of the liquid jet metering unit provided by the present invention.

Figure 7b is a measurement circuit diagram of the solenoid device state parameter T3 of the liquid injection metering unit provided by the present invention.

Figure 8 is a logic diagram of the flow passive closed loop control of the liquid injection metering unit provided by the present invention.

Figure 9a is a set of measured data based on a prediction of flow by a first energy model.

Figure 9b is a set of measured data based on a prediction of flow by a second energy model.

Figure 9c is a set of measured data based on a prediction of flow by a third energy model.

Figure 9d is a set of measured data based on a prediction of flow by a fourth energy model.

Figure 10 is an illustration of an application of the liquid jet metering unit of the present invention to an engine electrospray system.

Figure 11 is an illustration of an application of the liquid jet metering unit of the present invention to an SCR system.

Figure 12 is an illustration of an application of the liquid jet metering unit of the present invention to a DPF regeneration system.

Specific embodiment

As shown in FIG. 1 , a logic structural diagram of a liquid jet metering unit including a sleeve-plunger pump provided by the present invention includes a plunger pump 8 , a solenoid device 18 , a controller 13 , a nozzle 23 , and a return spring 10. Among them, the plunger pump device 8 includes a sleeve 11, a plunger 12, an inlet valve 16 and an outlet valve 17, and the sleeve 11 closely cooperates with the plunger 12 to form a pressure feed volume 9. The solenoid device 18 includes a coil 19, a yoke 20, a magnetic gap 21 and an armature 12a. The armature 12a and the sleeve 11 may be integrated into one body, and the armature 12a surrounds the sleeve 11 therein. The yoke 20 and the armature 12a are made of a magnetic conductive material, and the front end surface of the armature 12a is located in the magnetic gap. In the vicinity of 21, after the coil 19 is energized, the armature 12a and the sleeve 11 are driven by the solenoid device 18, and the forward movement causes the pressure feed volume 9 to be reduced, and the pressure in the pressure feed volume 9 is increased after being squeezed. Resulting that the liquid outlet valve 17 is opened, the liquid reaches the nozzle 23, under the action of the pressure, the nozzle 23 is opened, the liquid is ejected; the coil 19 is energized. After the end, under the action of the return spring 10, the sleeve 11 starts to move back. During the returning process, the inlet valve 16 is opened, and new liquid enters the pressure feed space 9 to prepare for the next cycle of injection.

As shown in FIG. 2, the logic structure diagram of the liquid injection metering unit including the plunger-sleeve pump provided by the present invention includes a plunger pump 8, a solenoid device 18, a controller 13, a nozzle 23, and a return spring. 10. Among them, the plunger pump device 8 includes a sleeve 11, a plunger 12, an inlet valve 16 and an outlet valve 17, and the plunger 12 closely cooperates with the sleeve 11 to form a pressure feed volume 9. The solenoid device 18 includes a coil 19, a yoke 20, a magnetic gap 21 and an armature 12a. The armature 12a is arranged coaxially with the plunger 12, the yoke 20 and the armature 12a are made of a magnetically permeable material, the front end face of the armature 12a is located near the magnetic gap 21, and after the coil 19 is energized, the armature 12a is coupled with the post. The plug 12 is driven by the solenoid device 18, and the forward movement causes the pressure feed volume 9 to be reduced, and the pressure of the liquid in the pressure feed volume 9 is increased after being squeezed, causing the liquid discharge valve 17 to open and the liquid to reach the nozzle 23, Under the action of the pressure, the nozzle 23 is opened and the liquid is ejected; after the coil 19 is energized, the plunger 12 starts to return to the position under the action of the return spring 10, and during the returning process, the inlet valve 16 is opened, and the new liquid enters. Pressing the space 9 prepares the injection for the next cycle.

In the liquid injection metering unit scheme provided in Figures 1 and 2, the outlet valve 17 is a one-way valve that is controlled by a differential pressure control switch, and the inlet valve 16 may be a one-way valve that is controlled by a differential pressure switch, or It is a spool valve controlled by a sleeve-plunger relative position, or a combination of a one-way valve that is controlled by a differential pressure control switch and a spooled valve that is controlled by a sleeve-plunger relative position.

As shown in FIG. 3a, a specific embodiment of a liquid-jet metering unit including a sleeve-plunger pump provided by the present invention comprises a solenoid device 18, a plunger pump 8, a return spring 10, a pump end 26, and a high pressure. Tube 25, nozzle 23, filter 31, low pressure volume 29 and output housing 37.

The solenoid device 18 includes a coil 19, a first inner yoke 20a, a second inner yoke 20d, an outer yoke 20b, an outer yoke end 20c, a magnetic gap 21 and an armature 12a. The outer yoke 20b is locked with the outer magnetic end portion 20c by plastic deformation of the projection 20b1, and the coil 19 is also fixed therein, and the first inner yoke 20a includes an inner exhaust passage 28 through which fluid can pass. The outer yoke 20b, the outer yoke end 20c, the first inner yoke 20a, and the second inner yoke 20d are each made of a magnetically permeable material, and the magnetic gap 21 is a non-magnetic material. The armature 12a is provided with a plurality of straight grooves 12e distributed in the circumferential direction to reduce the resistance of the reciprocating motion.

The plunger pump 8 includes a sleeve 11, a plunger 12, an inlet valve 16 and an outlet valve 17. The sleeve 11 cooperates closely with the plunger 12 to form a pressure feed volume 9. The sleeve 11 can be designed integrally with the armature 12a and use the same or different materials. The sleeve 11 is located inside the armature 12a and includes a plunger hole 27, an overflow hole 16b1, and a liquid inlet 30. The plunger 12 includes an end face 16b2, a discharge passage 12d, a restriction hole 12b located downstream of the discharge passage 12d, and a projection 12c at the end. The inlet valve 16 is a combination valve formed by a one-way valve 16a and a spool valve 16b. The one-way valve 16a is composed of a valve member 16a1, a valve spring 16a2 and a valve seat 16a3. The valve seat 16a3 can be integrally connected with the sleeve 11, and is a conical seat surface at and in communication with the inlet passage 30. The spool 16b includes an overflow hole 16b1 and an end surface 16b2 of the plunger 12. The opening and closing of the spool 16b is determined by the relative position of the plunger 12, and the spool 16b is closed when the plunger 12 is moved until the end face 16b2 exceeds the highest point of the overflow hole 12b. If the closing of the one-way valve 16a is later than the time when the overflow hole 16b1 is blocked, the process of starting the liquid feeding depends on the closing of the one-way valve 16a. On the contrary, the process of starting the liquid feeding depends on the overflow hole 16b1. Occlusion. The liquid discharge valve 17 is a one-way valve including an outlet valve member 17a, a discharge valve spring 17b, and an outlet valve seat 17c. The liquid outlet valve seat 17c is fixed to the plunger 12, and the fixing can be performed by tight fitting or welding.

The pump end 26 includes a pump end inlet port 26c, a support rod 26a and a limit member 26b. The inlet passage 30 allows the support rod 26a to extend into and contact the one-way valve member 16a1, and the limit member 26b is used to limit the electricity. The pivot 12a is returned to a position within a distance of the armature 12a from the pump end 26, the support rod 26a remains in contact with the one-way valve member 16a1 and prevents it from seating, so that on the one hand, when the armature 12a is returned to the initial position, the single The valve 16a is kept open so that the liquid has more time to enter the pressure feed volume 9. On the other hand, the gas in the pressure feed volume 9 can continue to pass over a distance that moves before the armature 12a moves away from the pump end 26. The check valve 16a is discharged to ensure the metering accuracy of the liquid.

The nozzle 23 is a ball valve type nozzle including a nozzle front valve seat 38, a hemispherical valve member 40, a nozzle rear valve seat 41, a nozzle valve spring 42, an injection hole 39, and the nozzle front valve seat 38 includes a spherical surface sealable with the hemispherical valve member 40. The conical seat surface, the nozzle rear valve seat 41 includes a plane which can form a seal with the plane of the hemispherical valve seat 43, the nozzle front valve seat 38 and the nozzle rear valve seat 41 are connected by welding, and a half is left in the connection. The ball valve member 40 opens the required movement space, and a filter 44 is provided at the entrance of the ball valve nozzle 23.

The high pressure pipe 25 includes a quick joint 25a that abuts the end boss 12c of the plunger 12 and a quick joint 25b that abuts the end boss 23a of the nozzle 23. The pump body 1 and the high pressure pipe 25 are sealed by an o-ring 32, and the nozzle 23 and the high pressure pipe 25 are sealed by an o-ring 33.

The filter 30 includes an inner skeleton 34, a filter mesh 35, and a filter lumen 36.

The working process of the liquid ejecting unit is as follows:

In the initial position of the movement, since the action of the return spring 10 abuts against the stopper 26b, the check valve 16a is in the open state due to the action of the support rod 26a, and the overflow hole 16b1 is in communication with the pressure feed volume 9, The gas-containing component easily escapes the pressure feed volume 9, and the pressure feed volume 9 is filled with liquid. When the armature 12a starts moving forward together with the sleeve 11 under the action of the electromagnetic force, part of the fluid in the pressure feed volume 9 is discharged through the inlet passage 30 and the overflow hole 16b1, including a part of the gas. When the armature 12a is moved by a certain distance, the overflow hole 16b1 is blocked by the surface of the plunger 12. The armature 12a continues to move, and the pressure feed volume 16 is continuously decreased. When the ball surface of the one-way valve member 16a1 is seated on the tapered valve seat 16a3, the liquid inlet check valve 16a is closed, and the pressure feeding process is started. The liquid pressure in the pressure feed volume 9 is gradually increased. When the pressure applied to the liquid discharge valve member 17a can overcome the force of the liquid discharge check valve spring 17b, the liquid discharge check valve 17 is opened, and the liquid enters the discharge passage 12d. The restrictor hole 12b enters the high pressure pipe 25 and passes through the filter net 44 to reach the hemispherical valve member 40. When the hemispherical valve member 40 is raised before and after the differential pressure rises to overcome the force of the nozzle valve spring 42, the hemispherical valve member 40 leaves the nozzle. The sealing cone of the front valve seat 38 is in close contact with the sealing plane of the nozzle rear valve seat 41, at which time the liquid is ejected through the orifice 39.

When the electromagnetic force acting on the armature 12a disappears, the armature 12a starts the return stroke under the action of the return spring 10, at which time the pressure drop is caused by the expansion of the pressure feed volume 9, and then the discharge check valve 17 is closed. The check valve 16a is opened, and the liquid quickly enters the pressure feed volume 9 under the action of the pressure difference. After the armature 12a continues to move for a certain stroke, firstly, the movement of the inlet valve member 16a1 is blocked by the support rod 26a, followed by the overflow hole. 16b1 is again in communication with the pressure feed volume 9, and part of the liquid can also enter the pressure feed volume 9 from the overflow hole 16b1, and the continued return of the armature 12a is blocked by the stopper 26b, and the cycle ends.

In the above process, the overflow hole 16b1 can also be redesigned so that the closing timing of the overflow hole 16b1 and the closing timing of the inlet valve 16a are reversed.

During the above work, the liquid enters the entire armature space 12d from the filter inner chamber 36 through the pump end inlet passage 26c, and enters the pressure feed volume 16 through the inlet passage 14, which is caused by the dissipation of heat and the partial liquid The evaporator space 12d evaporates, and the vaporized vapor enters the low pressure volume 29 from the internal exhaust passage 28 and is discharged to the outside through the discharge port 29a on the output end casing 37. The discharge port 29a includes a mounting step 29b for mounting the bubble tube to allow the gas to be more efficiently discharged from the pump body.

Figure 3b shows a further embodiment of the liquid-jet metering unit with a plunger-sleeve pump provided by the present invention. The main difference from the embodiment provided in Figure 3a is that the liquid-injecting metering unit 1 of the present embodiment employs a column. The plug 12 moves in synchronism with the armature 12a, and the sleeve 11 is fixed in a stationary structure. The armature 12a is substantially a cylindrical body and includes a through hole 45 penetrating both end faces. The through hole 45 may have a certain taper, and the tapered hole is expanded toward the liquid pressure feeding direction to achieve directional flow of the liquid in the internal space to cool the liquid jet metering unit 1 and improve the stability of its operation.

The armature 12a and the plunger 12 may be integral or may be transmitted by the connecting member 12b. The sleeve 11 is coaxially fixed to the output end housing 37, and the sleeve 11 is provided with a lateral overflow hole 16b1 and an axial straight plug hole 27 communicating. The plunger 12 is precision-slidably fitted in the sleeve 11, and its upper portion is always in contact with the armature 12a via the connecting member 12b. The overflow hole 16b1 and the plunger end surface 16b2 form the inlet valve 16. The liquid discharge valve 17 is composed of an outlet valve member 17a, The liquid outlet valve spring 17b and the liquid discharge valve seat 17c are a tapered surface that engages with the liquid discharge valve member 17a at the end 11a of the sleeve 11. The return spring 10 is disposed between the plunger 12 and the bottom of the armature space 12d.

The liquid entering from the liquid inlet port 46 enters the pressure feed volume 9 through the overflow hole 16b1, and when the armature 12a is driven downward by the electromagnetic force, the plunger 12 is pushed down by the connecting member 12b, once the suction overflow hole 16b1 is pressed by the plunger 12 The wall is blocked, the inlet valve 16 is closed, the pressure feed stroke is started, and the liquid pressure in the pressure feed volume 9 is increased, thereby opening the liquid discharge valve 17, and the pressure liquid enters the liquid outlet 47 and the high pressure pipe 25, and reaches the nozzle 23 once the pressure is reached. When the opening pressure of the nozzle 23 is exceeded, the nozzle sprays the liquid mist outward. The nozzle 23 can be a poppet valve that is opened by pressure.

During this process, the liquid entering through the liquid inlet port 46 together with the air bubbles therein can directly enter the discharge port 29a through the discharge port 28 (the bubble passage also allows liquid to pass) the armature space 12d and the through hole 45. Forming a return flow to remove heat.

FIG. 4 is a schematic diagram showing the measurement of the state parameters of the solenoid device of the liquid jet metering unit provided by the present invention, wherein a control main chip 13a is a single chip microcomputer, and a semiconductor switch tube 13b for controlling the solenoid device 19 is shown. A circuit 13c for measuring the current through the coil, a circuit 13d for measuring the voltage across the coil, and a T3 generating circuit 13e.

FIG. 5a shows a specific circuit for measuring the state parameter voltage of the solenoid device of the liquid jet metering unit provided by the present invention, which is a common voltage dividing circuit for measuring voltage, and includes two resistors 102.

Fig. 5b shows a solenoid device state parameter current measuring circuit of the liquid jet metering unit provided by the present invention, which is a circuit for measuring a common measuring current, which comprises an operational amplifier 101 and a corresponding resistor 102.

As shown in FIG. 6, the flow active closed loop control logic of the liquid injection metering unit provided by the present invention comprises the following steps:

Step 111: According to the multi-point flow test of the liquid injection metering unit, establish a relationship between the injection quantity Q and the effective output work Wn of the solenoid device (hereinafter referred to as the effective output work), which may be discrete data or may be based on discrete data. The fitted relationship, α is also calibrated, and then the data or relationship is stored in the controller 13;

Step 112, determining a target effective output work Wno according to the target injection amount Qo;

Step 113, the controller 13 applies a voltage to the coil 19 through the semiconductor switch tube 13b;

Step 114, collecting the current Id and the voltage Vd of the coil 19 according to a certain time interval;

Step 115, selecting a method provided by the present invention to calculate a current effective output work Wnc;

Step 116, comparing the target effective output work Wno with the current effective output work Wnc;

Step 117, if Wno-Wnc is smaller than an allowable small amount e, it means that the current injection target is achieved, and the driving is ended. Otherwise, continue driving and return to step 114 to continue real-time monitoring.

As shown in FIG. 7a, the physical parameter definition of the solenoid device state parameter T3 of the liquid jet metering unit provided by the present invention is that after the coil 19 is powered off, the induced electromotive force at both ends of the coil suddenly rises and then falls along the curve 103. When the voltage drops to a reference voltage Vf, the time interval from the power-off of the coil 19 to the current time is defined as T3, and the single-chip microcomputer 13a can obtain a specific value according to the measurement signal 104 of T3.

The measurement signal 104 of T3 can be generated by a circuit, as shown in FIG. 7b, the measurement circuit of the solenoid device state parameter T3 of the liquid injection metering unit provided by the present invention, wherein the reference voltage Vf is divided by the power supply voltage Vcc through the resistor Forming, referring to FIG. 4, the signal of one end M of the coil is connected to one input terminal of the operational amplifier 101a, Vd is connected to the other input end of the same operational amplifier 101a, and the output of the amplifier 101a is connected to one of the other operational amplifiers 101b. The input terminal, and the reference voltage Vf is connected to the other input terminal of the operational amplifier 101b, so that the T3 signal can be detected at the output of the operational amplifier 101b, which is a square wave signal (as shown in Fig. 7a).

Based on the T3 signal, as shown in FIG. 8, a passive closed-loop control logic for flow control of the liquid injection metering unit provided by the present invention can be designed, that is, including the following steps,

Step 121, according to the multi-point flow test of the liquid injection metering unit, establish a relationship between the injection quantity Q and T3, which may be discrete data, or may be a relationship that is fitted according to discrete data, and then the data or The relationship is pre-stored in the controller 13;

Step 122, the T1=f(T3) relationship of the liquid ejection metering unit is obtained through a simple experiment, and the differential relationship between T3 and T1 is obtained according to the discrete data, that is, dT1=df(dT3), and the data is discrete or Form, or fit into a function expression, a relational expression, which is pre-stored in the controller 13;

Step 123, according to the target injection amount Qo, determine the target T3, that is, T3o;

Step 124, according to the pre-stored relationship T1 = f (T3), estimate the drive pulse width T1 to achieve T3o;

Step 125, determining the dynamic correction amount dT1 of T1 according to the feedback information of the previous cycle;

Step 126, driving the coil 19 according to the pulse width T1 + dT1;

Step 127, collecting a signal value of T3;

Step 126, calculating the difference between the current T3 and the target T3, that is, dT3=T3o-T3;

Step 127, according to the relationship pre-stored in the controller 13 in step 122, calculate the correction amount dT1=df(dT3) of T1.

Returning to step 125, the information of dT1 is stored in the controller 13.

The above-mentioned passive closed-loop control of the injection amount of the liquid ejecting unit, although it is not formally impossible to accurately achieve the control target in the current pulse, since the interval between adjacent two pulses is short, the liquid ejecting unit itself and the surrounding fluid The state of the change during this period is negligible, so in fact, higher control accuracy can be obtained.

Figure 9a shows a set of measured data based on a first energy model and its linear fit relationship. The first energy model refers to Wn=Et-Et0, which ignores the energy consumption of the coil resistance, ignoring the solenoid. The inductive energy storage of the device ignores the liquid flow resistance power consumption and the energy storage of the return spring, and directly changes the total energy input to the solenoid device, that is, the total energy input and the input before the injection. The difference between the total energy is treated as the effective output of the solenoid device. The simplified energy model does not have a good linear relationship with the injection quantity Q, but it also has some practical significance because it can eliminate some of the state of the injection unit. Change the factors that affect the amount of injection.

FIG. 9b is a set of measured data and a linear fitting relationship thereof for predicting the flow rate based on the second energy model, and the second energy model is based on the first energy model, and the influence factor of the coil resistance energy consumption is increased. That is: Wn=(Et-Et0)-(Er-Er0). It can be seen that the prediction of the injection quantity Q based on the second energy model is improved relative to the first energy model, but is not significant.

Figure 9c is a set of measured data based on the prediction of the flow rate based on the third energy model. The third energy model is based on the second energy model and increases the influencing factor of the energy storage of the inductor, namely: Wn = (Et- Et0)-(Er-Er0)-(Ein-Ein0). It can be seen that the prediction based on the third energy model for the injection quantity Q has a high degree of precision.

Figure 9d is a set of measured data and a linear fit relationship based on the prediction of the flow rate based on the fourth energy model, the fourth energy model is associated with the effective output work and T3 as a linear relationship, that is, Wn = λ (T3-T30 ), where T30 is T3 at the beginning of injection, and λ is a pending coefficient that can be determined by flow measurement experiments. It can be seen from the measured results that the fourth energy model can give a better prediction result of the injection amount.

10 is an example of a liquid injection metering unit provided by the present invention applied to an engine electronic fuel injection system. The pump nozzle of the illustrated example may be the sleeve-plunger pump shown in FIG. 3a, and the application scheme shown in FIG. 3a is required. The sleeve-plunger pump is placed upside down, which is more advantageous for the elimination of air bubbles near the inlet valve 16a. Examples include a fuel tank 132, a plunger pump 8, a high pressure injection pipe 25, a nozzle 23, and a controller 13. The fuel tank 132 includes a mounting boss 132a that can be secured to the fuel tank mounting table by bolts 131 and sealed by a gasket 138. The filter 31 is located inside the fuel tank 132, and the nozzle 23 is mounted at the intake nozzle 134 of the engine 133 near the intake valve. The controller 13 also functions as an electrospray controller of the engine, drives the liquid jet metering unit 1 to operate via the cable 135, and meters the gasoline ejected through the nozzle 23, mixes with the air, and enters the cylinder 136 of the engine 133. Of course, the metering controller 13 also passes the cable 137 and the engine. Other mechanisms of the electronic control system are connected, such as engine angular sensor.

The liquid injection metering unit shown in this example can also be applied to a gasoline engine in-cylinder fuel direct injection system.

Figure 11 is an illustration of an application of the liquid jet metering unit of the present invention to an SCR system, which may be the sleeve-plunger pump of Figure 3a. Examples include a urea tank 141, a support 142, a metering injection unit 1, a controller 13, a mixing infusion tube 155, an injector 156, an exhaust line 157 with an SCR catalytic converter 159, along the exhaust The flow direction is sequentially arranged with a temperature sensor 158 and a NOx or ammonia gas sensor 160, which are respectively located on both sides of the catalytic converter 158.

The metering injection unit 1 includes a plunger pump 8, a high pressure pipe 25, a nozzle 23 and a bubble tube 145. The bubble discharging tube 145 extends to the top of the solution, and the filter end 146 is installed at the outlet end to ensure that the clean solution in the plunger pump 8 is not contaminated and the dirt is prevented from entering.

The bracket 142 includes respective sensors 144 (including a temperature sensor, a liquid level sensor, etc.), a plunger pump mounting table 144a for fixing the plunger pump 8, a circulating water heater 161, and a gas-liquid mixing chamber 148 at the other end of the bracket 142. Install the controller 13 on it. The bracket 142 is attached to the upper end surface 141a of the urea tank, and one end thereof is placed inside the urea tank 141 together with a plunger pump 8 fixed to the mounting table 144a, and the plunger pump 8 is extended to the bottom of the urea tank 141. The gas-liquid mixing chamber 148 includes an intake pipe joint 149 that communicates with the intake passage 150 for introducing high-pressure air, an infusion pipe joint 147 that communicates with the outlet passage 151, and a nozzle mounting passage 152 such that the nozzle 23 The orifice 39 extends through the mounting channel 152 into the interior of the mixing chamber 148 and is sealed by the bracket 142.

The injector 156 is mounted on the exhaust duct 157 and may be a simple orifice nozzle or a swirl nozzle without a nozzle valve. This solution can achieve the following different objectives for different applications: one is to facilitate liquid atomization and increase the oxygen content of the exhaust pipe, the second is to avoid the blockage and damage of the conveying pipeline caused by icing, and the third is to avoid evaporation of water. After the urea is precipitated, the pipeline is blocked, and the fourth is to avoid the clogging of the nozzle by the fuel coking.

The working process of the SCR system given by the present invention is as follows.

The metering controller 13 calculates the engine operating conditions sent from the engine main control unit (not shown), the exhaust gas temperature sensor 159, the NOx or ammonia gas sensor 160, the signals of the sensors 144 in the liquid storage tank, and the like. The required urea liquid flow rate is then judged whether the urea liquid injection system can work normally. If possible, the liquid injection metering unit 1 is controlled to operate, and the urea liquid in the liquid storage tank is pumped into the high pressure pipe 25 and then injected into the mixing by the nozzle 23. Cavity 148. At the same time, the high pressure air is mixed into the mixing chamber 148 via the pressure gauge 154, the solenoid valve 153, the intake pipe joint 149, and the intake port 150, and a spray valve is mixed therein, and a check valve can be installed between the solenoid valve 153 and the intake pipe joint 149. , allowing the airflow to pass in one direction. The mixed liquid enters the mixed infusion tube 155 through the discharge passage 151 and the infusion tube joint 147. Finally, the mixture is sprayed into the exhaust pipe 157 by the ejector 156. The urea liquid is pyrolyzed into ammonia gas under the action of the engine exhaust high temperature, and is uniformly mixed with the engine exhaust gas into the SCR catalytic converter 159. As a result, NOx will be efficiently decomposed into harmless N ₂ and H ₂ O to achieve the purpose of evolutionary exhaust.

During the above work, the controller 13 determines whether the urea liquid freezes according to the signal of the temperature sensor 144 in the liquid storage tank, and if there is ice, controls the water valve (not shown) to make the cooling water of the engine enter. The circulating water heater 161 in the reservoir is heated to melt the ice.

Figure 12 is an illustration of a liquid injection metering unit provided by the present invention for use in a DPF regeneration system, which may be the sleeve-plunger pump of Figure 3b. Examples include a sub tank 173, a plunger pump 8, a high pressure pipe 25, a nozzle 23, a controller 13, an exhaust pipe 170, a differential pressure sensor 180, and a temperature sensor 181. The controller 13 may be a metering module for receiving a working signal of the main control unit, or a control unit including a DPF system.

In the application example, a diesel particulate filter (DPF) 171 is installed on the exhaust pipe 170, an oxidizing catalyst DOC179 may be connected before the DPF, or a precious metal catalyst may be directly coated on the DPF filter in the DPF 171. The fuel (diesel) nozzle 23 of the regenerative DPF 171 is disposed upstream, and when the regeneration condition is reached, the fuel is injected into the engine exhaust pipe 170, and the remaining air in the engine exhaust 172 is combusted to exhaust the engine. The temperature of 172 rises and enters the DPF 171, thereby igniting the particulate matter mainly composed of soot collected in the DPF 171 to achieve the purpose of regenerating the DPF. In this system, the fuel injected from the nozzle 23 should be as small as possible, but the engine exhaust 172 must be brought to a sufficiently high temperature, so that the fuel atomization is required to be good and the distribution is reasonable. The nozzle 23 can be selected from a poppet type structure that is resistant to coking and pollution. A sub tank 173 is included, and the sub tank 173 is located above the liquid injection metering unit 1 so that the fuel in the sub tank 173 can enter the liquid injection metering unit 1 by gravity to form a normal oil supply. The return oil of the engine high pressure injection system (preferably in series) enters the sub tank 173 through the oil inlet 179 and then returns to the main fuel tank of the engine through the oil return port 178. The fuel of the auxiliary fuel tank 173 may also be directly from the low pressure fuel supply pump of the high pressure injection system of the engine, or may be taken from the main fuel tank of the engine by an additional pump (such as a vacuum pump) or gravity. At least one filter system is arranged between the engine main fuel tank and the liquid injection metering unit 1. If the low pressure oil return from the engine high pressure injection system, no additional filter may be needed, otherwise a fuel filter 31 may be arranged. The fuel tank 173 includes an oil inlet passage 179 connected to a diesel combustion system return line (not shown) and a return oil passage 178 connected to a main oil tank (not shown). The oil inlet of the plunger pump 8 is introduced into the fuel from the fuel auxiliary tank 173 and filtered through the filter 31 through the oil inlet pipe 175, and is pumped to the injection pipe 177 under the control of the controller 13, and then injected into the engine exhaust pipe from the nozzle 23. 170. The controller 13 simultaneously measures the amount of injected fuel, and determines whether the injected fuel amount is appropriate according to the detected engine operating condition, DPF pressure resistance, exhaust state, and DPF temperature (not shown), and whether it is necessary to continue. . The oil return of the plunger pump 8 is returned to the upper space of the fuel tank 173 through the oil return pipe 174. The liquid outlet 182 of the sub tank 173 is located at the bottom, and the liquid return port 177 is located at a higher position, so that the oil tank 173 can still operate normally with a small amount of oil storage.

The working process of the application application system is as follows:

The soot from the engine is filtered by the DPF 171 and gradually accumulated therein. As the amount of accumulated soot increases, the pressure difference ΔP before and after the DPF 171 gradually increases, and when the controller 13 detects that the ΔP is greater than the specific value by the differential pressure sensor 180 When the value (has or will affect the power output of the engine), and when the temperature sensor 181 detects that the temperature is greater than a specific value, it is determined by the throttle sensor signal of the engine or other communication means that the oxygen component in the engine exhaust pipe 172 is greater than a specific value. At this time, the controller 13 drives the liquid jet metering unit 1 to inject fuel into the engine exhaust pipe 172 through the nozzle 23, and the smaller the injection amount, the better, as long as it is possible to remove the soot in the DPF 171 by oxidation. The injection amount may be set in advance in the memory of the controller 13, or may be feedback controlled based on a sensor such as temperature, for example, an oxygen sensor may be added.

In the application example shown in Fig. 12, the oil supply to the oil inlet of the plunger pump 8 may be diesel fuel to which a combustion improver is added, for example, diesel fuel containing a ignition catalyst. In this case, the fuel tank 173 is used for regeneration. Fuel storage box.

In addition, the fuel metering injection unit of the present invention can also be used for quantitatively adding fuel additive to the fuel in the field, for example, instantaneously injecting a fuel carrying catalyst (FBC) into the main fuel of the diesel engine to reduce the ignition temperature of the diesel particulate matter, or Instantly inject a combustion improver into the DPF active regenerative fuel to reduce the ignition temperature of the mixture of regenerative fuel and engine exhaust, and the like.

The above examples are merely illustrative of the invention, but are not intended to limit the invention, and further modifications are possible within the scope of the invention.

Claims

A liquid injection metering unit and control method, comprising: an injection unit and a metering controller, the injection unit comprising a solenoid device, a plunger pump and a nozzle, the plunger pump comprising a column The plug and the sleeve, the plunger and the sleeve cooperate to form a pressure delivery volume, the pressure delivery volume is connected to the inlet valve and the outlet valve, and the liquid is discharged from the inlet valve into the pressure delivery volume from the outlet valve, and the metering controller is a screw The conduit device provides a drive signal, and the metering controller includes a monitoring device that monitors the status parameters of the solenoid device, including an algorithm for predicting the effective output of the solenoid device using the state parameter, including using the effective output of the solenoid device as a variable A method of closed-loop control of the flow rate of a liquid injection metering unit.
A liquid jet metering unit and control method according to claim 1, wherein said plunger pump includes a return spring, and the sleeve reciprocates under the driving of the solenoid device and the return spring, resulting in an alternate volume of the pressure feed volume. Variety.
A liquid jet metering unit and control method according to claim 1, wherein said plunger pump includes a return spring, and the plunger reciprocates under the driving of the solenoid device and the return spring, resulting in an alternate volume of the pressure feed volume. Variety.
The liquid jet metering unit and control method according to claim 3, wherein said plunger includes an armature, said armature being substantially a cylinder, and the armature includes a through hole penetrating both end faces.
A liquid jet metering unit and control method according to claim 2 or 4, wherein a high pressure pipe is included between the liquid discharge valve and the nozzle.
A liquid jet metering unit and control method according to claim 5, comprising a gas-liquid mixing chamber, wherein the liquid is sprayed into the gas-liquid mixing chamber by the nozzle, and the liquid is mixed with the gas liquid and then ejected through an injector. .
A liquid jet metering unit and control method according to claim 6 wherein said injector is a swirl nozzle.
A liquid injection metering unit and control method according to one of claims 1 to 7, wherein the state parameters of the solenoid device include current and voltage through the solenoid.
The liquid injection metering unit and control method according to claim 8, wherein the algorithm for predicting the effective output of the solenoid device comprises the steps of estimating the total energy output by the metering controller, and estimating the power consumption of the solenoid resistor. The step of estimating the energy storage of the solenoid device.
A liquid injection metering unit and control method according to claim 9 wherein the step of estimating the total energy output by the metering controller includes the step of integrating the product of the current and voltage of the monitored solenoid with time.
A liquid ejection metering unit and control method according to claim 10, wherein the step of estimating the power consumption of the coil resistor comprises integrating the product of the square of the current of the monitored solenoid and the solenoid resistance with time. step.
A liquid injection metering unit and control method according to claim 11 including the step of calculating the energy storage of the solenoid of the solenoid device using the monitored solenoid current.
A liquid jet metering unit and control method according to claim 12, characterized in that, under the condition of liquid injection, the coil resistance power consumption and the inductance energy storage of the solenoid device are respectively processed to be the injection amount with the liquid. Linear relationship.
The liquid injection metering unit and control method according to any one of claims 1 to 7, wherein the solenoid device state parameter includes a time T3 required for the electromotive force to drop to the reference voltage after the coil is de-energized, and the prediction is performed. The algorithm for effectively outputting power of the solenoid device includes the step of processing the effective output work of the solenoid device in a linear relationship with T3.
A liquid injection metering unit and control method according to any one of claims 1 to 14, wherein a flow target of the liquid injection metering unit per unit time is realized, and the effective output of the solenoid device is maintained by each pulse. Constantly, the operating frequency of the liquid jet metering unit is adjusted to achieve.
A liquid injection metering unit and control method according to any one of claims 1 to 14, wherein a flow rate target of the liquid injection metering unit per unit time is achieved, by maintaining the operating frequency of the liquid injection metering unit unchanged To achieve the goal by adjusting the effective output of each pulse of the solenoid device.
A liquid jet metering unit and control method according to any of claims 1-14, including a method of predicting a liquid level by measuring fluid resistance of the liquid to the plunger pump moving member.
A metering module comprising the liquid jet metering unit and the control method according to any one of claims 1-17, characterized in that it comprises a bracket formed by a melting tube, the spraying unit is fixed at one end of the bracket, and the controller Fixed to the other end of the bracket.