CN201983933U - System for testing thawing capability of SCR (selective catalytic reduction) system - Google Patents
System for testing thawing capability of SCR (selective catalytic reduction) system Download PDFInfo
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- CN201983933U CN201983933U CN2010206927530U CN201020692753U CN201983933U CN 201983933 U CN201983933 U CN 201983933U CN 2010206927530 U CN2010206927530 U CN 2010206927530U CN 201020692753 U CN201020692753 U CN 201020692753U CN 201983933 U CN201983933 U CN 201983933U
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Abstract
The embodiment of the utility model discloses a system for testing the thawing capability of an SCR (selective catalytic reduction) system. The SCR system comprises a urea tank, a urea pump, a urea nozzle and a urea pipeline, wherein the urea tank is provided with a passive heat exchanger, and the urea pipeline is provided with an electric heater. The testing system comprises a temperature control heating unit, an SCR post treatment electronic control unit ECU, detection equipment and data acquisition and processing equipment, wherein the temperature control heating unit carries out heating, supplies heat medium to the heat exchanger of the urea tank, and supplies the heat to a urea solution in the urea tank through heat medium circulation; the SCR post treatment electronic control unit ECU controls a working state of the SCR system to be detected and an electric heating state of the urea pipeline; the detection equipment comprises a temperature sensor used for detecting the temperature of the urea solution in the urea tank; and the data acquisition and processing equipment is in coupling with the detection equipment or the ECU and used for determining a thawing time according to a detection result and a predetermined standard of the detection equipment.
Description
Technical field
The utility model relates to the method for testing and the device of the ability of thawing of SCR system, relates to the method for testing and the device of the ability of thawing of urea box in the test SCR system and urea pipe particularly.
Background technology
Along with increasing rapidly of China's rapid economic development and vehicle population, the pressure of China environmental protection aspect is increasing.Stipulated to reduce the oxides of nitrogen of vehicular discharge in the atmosphere.A kind of known mode that generally adopts that realizes this target is to use SCR (Selective Catalytic Reduction, be called for short SCR) method, this method makes oxides of nitrogen reduce by a kind of reductive agent (normally ammonia) being injected gas outlet.The basic functional principle of SCR method commonly used is as follows in the vehicle at present: waste gas enters the gas outlet after booster turbine flows out, and by the injection unit that is installed on the gas outlet quantitative aqueous solution of urea is sprayed in the gas outlet with vaporific form simultaneously.Urea droplets issues in the high-temp waste gas effect that unboiled water is separated and pyrolytic reaction, generates needed reductive agent ammonia (NH3).Ammonia (NH3) optionally is reduced to nitrogen (N2) with the oxides of nitrogen in the exhaust (NOx) under the effect of catalyzer.By this SCR method, the oxides of nitrogen of the high concentration that transmitter produces in combustion process has obtained processing when leaving gas outlet.
Northern area in China, winter temperature are low especially usually, sometimes even reach subzero 30 to 40 degrees below zero.And in view of the normally used urea liquid of above-mentioned SCR system (for example 32.5wt% urea liquid) at low temperatures (for example-11 ℃) can freeze), if the urea liquid that freezes after the transmitter running can not dissolve as early as possible, then can not supply urea oxides of nitrogen in the solution removal tail gas causes exhaust to worsen.In order to guarantee tail gas emission compliance under cold snap, the urea box and the urea lines of the solution that is used to supply urea need have the good ability of thawing.Whether qualified the ability of thawing of this SCR system also becomes weighs SCR system an important test index.
In the prior art, to the test of the ability of thawing of urea box and urea pipe, carry out on engine pedestal, this test is also referred to as engine bench test.When engine bench test, engine pedestal must wholely be arranged in the low-temperature test storehouse.When the ability of thawing of the urea box that uses and urea pipe in the vehicle of test different model, need to change different engine pedestals.In addition, this test operation on engine pedestal is complicated, and cost is higher.
Therefore, need a kind of improved being used for urea box and urea pipe the thaw method of testing and the equipment of ability, it more flexibly, accurately and can effectively save cost.
The utility model content
According to an aspect of the present utility model, the test macro that provides a kind of urea liquid that is used for testing the SCR system to thaw ability, tested SCR system comprises urea box, urea pump, urea nozzle, and between urea box and the urea pump and the urea pipe between urea pump and the urea nozzle, described urea box has no source heat exchanger, described urea pipe has electric heater unit, described test macro comprises: the temperature control heating unit, the thermal medium that its heating provides to the heat exchanger of urea box, making provides heat by the urea liquid of thermal medium circulation in urea box; SCR aftertreatment electronic control unit ECU, it controls the duty of tested SCR system and the electrical heating state of urea pipe; Checkout equipment comprises the temperature sensor of the temperature of the urea liquid that is used for detecting urea box; Data acquisition process equipment, it is coupled to checkout equipment and/or ECU, is used for determining thawing time according to the testing result and the preassigned of checkout equipment.
According to an embodiment of the present utility model, described test macro is tested the thawing time of urea box under first test pattern.In described first test pattern, tested SCR system is set at low temperature environment, makes urea box freeze fully, and by ECU urea pump, urea nozzle and urea pipe is arranged under the normal operating conditions.Measurement comprises: regulate temperature control heating unit heat hot medium; Data acquisition process equipment reaches first threshold according to the temperature of the urea liquid that is detected and judges that the urea box bottom thaws successfully, thereby determines the preliminary thawing time of urea box; And/or data acquisition process equipment reaches the second threshold decision urea box according to the temperature of the urea liquid that is detected and fully thaws, thereby determine the abundant thawing time of urea box.
According to another embodiment of the present utility model, test macro is tested the thawing time of urea pipe under second mode of operation.In described second test pattern, tested SCR system is set at low temperature environment, makes urea pipe fully freeze, and urea box thaws in advance, and by ECU urea pump and urea nozzle is arranged under the normal operating conditions.In test: the control by ECU makes the electric heater unit of urea pipe be in heated condition; Data acquisition process equipment reaches the particular job state according to urea pump or nozzle and judges that urea pipe thaws successfully, thereby determines the thawing time of urea pipe.
According to another embodiment of the present utility model, test macro also comprises the thermal medium pump, is arranged on the pipeline between temperature control heating unit and the urea box, is used to provide the circulation of thermal medium.
According to another embodiment of the present utility model, test macro also comprises solenoid valve, is arranged on the pipeline between temperature control heating unit and the urea box, is used for realizing thermal medium round-robin break-make according to the control of ECU.
According to another embodiment of the present utility model, test macro also comprises: temperature and pressure transmitter is used for detecting the temperature and pressure of thermal medium cyclic process.
Description of drawings
By shown embodiment in conjunction with the accompanying drawings is elaborated, above-mentioned and other features of the present utility model will be more obvious.In the accompanying drawings, identical label is represented same or analogous parts, wherein:
Fig. 1 shows the synoptic diagram according to the test macro of the ability of thawing of the urea liquid in the test SCR system of an embodiment of the present utility model.
Fig. 2 shows the synoptic diagram according to the test macro of the ability of thawing of the urea liquid in the test SCR system of a preferred embodiment of the present utility model.
Fig. 3 shows the process flow diagram according to the method for testing of the ability of thawing of the urea liquid in the test SCR system of an embodiment of the present utility model.
Fig. 4 shows the process flow diagram according to the method for testing of the ability of thawing of the urea liquid in the test SCR system of another preferred embodiment of the present utility model.
Embodiment
Hereinafter, the urea box in the test SCR system that the utility model is provided by embodiment with reference to the accompanying drawings and urea pipe the are thawed test macro and the method for ability is described in detail.Should be appreciated that following embodiment only is illustrative, and not restrictive.
Before introducing test macro of the present utility model and method, at first briefly introduce tested SCR system.
The SCR system is divided into control module, urea dosage device and catalytic reaction unit three parts usually according to function.The control module of SCR system is called SCR aftertreatment electronic control unit (being called for short ECU), is mainly used to carry out the SCR control strategy, and it may integrate with engine electronic control unit.For example control the urea dosage device, so that spraying urea liquid is mapped in the exhaust airstream according to demand at regular time and quantity according to (these factors are indicated by sensor signal usually) such as NOx concentration in environment temperature, delivery temperature, urea level, urea temperature, urea pressure, the exhaust.The urea dosage device is used for the control according to ECU, and quantitative urea liquid is sprayed in the gas outlet with vaporific form.Urea droplets issues in the high-temp waste gas effect that unboiled water is separated and pyrolytic reaction, generates needed reductive agent ammonia (NH3).Ammonia (NH3) optionally is reduced to nitrogen (N2) with the oxides of nitrogen in the exhaust (NOx) under the effect of catalyzer.The part that above-mentioned reaction takes place in gas outlet is called the catalytic reaction unit.
The urea dosage device mainly comprises urea box, urea pump, urea nozzle and connecting line (also claiming urea pipe).Under the low temperature, the urea liquid in urea box and the urea pipe can freeze, and this will cause the urea dosage device can't operate as normal, carries out catalytic reduction reaction thereby can't be as required the urea liquid of ormal weight be sprayed into gas outlet.For fear of the problem that cold snap freezes to bring owing to urea liquid down, the urea dosage device also comprises heating component usually, is used for heating to urea box and urea pipe.
During engine running, when producing exhaust, can produce a large amount of heats, generally utilize the liquid coolant of the heat of transmitter that urea box is heated at present.For this reason, the heat exchanger of urea box is connected with the liquid circulation pipeline of engine, and this connection can be controlled by solenoid valve.Judging urea at ECU by urea box temperature sensor and/or environment temperature sensor (for example need thaw, temperature is less than or equal to first setting value, as-7 ℃) time, ECU can indicate and open solenoid valve, make and the urea liquid in the urea box to be thawed can the flow through heat exchanger of urea box of the engine coolant of heat.And when ECU detects the urea temperature and reaches higher temperature (for example, temperature is greater than or equal to second setting value, as 0 ℃) by the urea box temperature sensor, can close solenoid valve, thereby the transmitter liquid coolant no longer flows into the heat exchanger of urea box.Like this, can be so that the liquid temperature in the urea box keeps within the specific limits.
For urea pipe, normally dispose electric heater it is heated.Starting or stoping usually of this electric heater also controlled by ECU.
Urea nozzle is arranged on the gas outlet usually.When transmitter moved, Tail Pipe Temperature was very high, so can there be frozen problem in urea nozzle.
According to foregoing description, the urea liquid ability of thawing in the SCR system relates generally to the heating efficiency of urea box heat exchanger and electrical heating urea pipe as can be seen.
In the conventional test mode, be the ability of thawing of the urea liquid in the test SCR system on the transmitter stand.When engine bench test, engine pedestal must wholely be arranged in the low-temperature test storehouse.When the ability of thawing of the urea box that uses and urea pipe in the vehicle of test different model, need correspondingly change different engine pedestals.Such testing cost is high.In addition, this test operation on engine pedestal is complicated, and the factor that influences its result is very many.For example the individual performance of transmitter, the fault when moving or the like all can influence test result.
In order to overcome the shortcoming of above-mentioned conventionally test, of the present utility model proposed a kind of more flexibly, accurately and can effective cost-effective urea box well heater and the method for testing and the device of electrical heating urea pipe.
Main basic thought of the present utility model is: in test, need not dispose transmitter, and be to use temperature control heating unit simulated engine to provide the thermal medium of heat to test the ability of thawing of SCR system.Can realize being used for the temperature of the heating medium of urea box heat exchanger, the accurate adjusting of flow according to testing scheme of the present utility model, solve and in test process, used engine coolant to regulate the problem of difficulty as the heating medium of urea box well heater.And the temperature control heating unit can easily be simulated the medium of the heat that generates under the true ruuning situation of various types of engines, like this according to proving installation of the present utility model can test different types the SCR system.The SCR system auxiliary for air and non-air is auxiliary, and/or can use according to pilot system of the present utility model for the SCR system of the nozzle with mechanical valve or solenoid control and to test heating efficiency.
Following mask body is elaborated to each embodiment of the present utility model with reference to the accompanying drawings.
Fig. 1 shows the block diagram of test macro 100 of the ability of thawing of urea liquid that is used for testing the SCR system according to an embodiment of the present utility model.As shown in the figure, test macro 100 comprises temperature control heating unit 12, checkout equipment 13, ECU 14 and data acquisition process equipment 15.
The equipment under test 20 of test macro 100 is the SCR system.As mentioned above, the SCR system generally include urea box, urea pump, urea nozzle and connecting line (also promptly between urea box and the urea pump and the urea pipe between urea pump and the urea nozzle), and described urea box has no source heat exchanger, and described urea pipe has electric heater unit.The heat exchanger of urea box places in the urea box usually, preferably places the bottom of urea box.The electric heater unit of urea pipe is arranged around urea pipe usually.
Temperature control heating unit 12 is used to heat the thermal medium that the heat exchanger to urea box provides, to provide heat by the urea liquid of thermal medium circulation in urea box.
The thermal medium of supplying with the heat exchanger of urea box can be the circulating cooling liquid of temperature control heating unit, and it can be water or other the thermal medium that can be used as the transmitter liquid coolant.The outlet of the circulating cooling liquid of temperature control heating unit can directly or by valve be connected with the entrance and exit of urea box heat exchanger respectively with inlet.So, flow into the heat exchanger of urea box through the thermal medium (liquid coolant of instant heating) of temperature control heating unit heating, carry out heat interchange with urea liquid in the urea box, the thermal medium that turns cold then flows out from the outlet of heat exchanger again, flows to the temperature control heating unit again.So, can provide heat by the urea liquid in urea box by the thermal medium circulation, so that thaw.
Truth when the thermal behavior of temperature control heating unit should be moved with transmitter as much as possible is identical.For example, this can realize by the power of control temperature control heating unit, and the curve of the thermal power vs time when making the curve of thermal power vs time of temperature control heating unit move with transmitter is consistent.Perhaps, this also can be by control temperature control heating unit, makes consistent realization of round-robin temperature, pressure and/or flow velocity of thermal medium round-robin temperature, pressure and/or flow velocity and engine coolant.
SCR aftertreatment electronic control unit ECU 14 is used to control the duty of tested SCR system.ECU 14 serves as the control module of SCR system.ECU 14 can gather (these factors are indicated by sensor signal usually) such as NOx concentration in environment temperature, delivery temperature, urea level, urea temperature, urea pressure, the exhaust usually, and control the urea dosage device according to these factors, so that spraying urea liquid is mapped in the exhaust airstream according to demand at regular time and quantity.In according to embodiment of the present utility model, because purpose is in order to test the ability of thawing of SCR system, and not on real transmitter stand, to carry out test, therefore can be easily by ECU being set to satisfy other SCR conditions of work except that the test factor.Can get rid of of the influence of other factors like this to test result.For example, when test urea box thawing time, can simply the every other condition except that the urea temperature of urea box (for example NOx concentration in environment temperature, delivery temperature, urea level, urea pressure, the exhaust or the like) all be set to satisfy the SCR injection conditions.And the urea temperature of urea box will be obtained by the temperature sensor that is arranged in the urea box by ECU.Should be appreciated that preferably, when arranging more sensor in the test macro, ECU can be known various conditions (for example urea pressure, urea level or the like) from real sensor.
ECU can also control the heated condition of hot heating urea pipeline.Can easily, ECU make the electrical heating urea pipe be in heated condition or end heated condition by being set.
In addition, ECU can also control the operation of the miscellaneous part in this test macro.For example, when the circulation of the thermal medium of temperature control heating unit is when being connected with the heat exchanger of urea box by valve, whether the operation of all right operation valve of ECU heats urea box to control.
Because being connected in the connection of ECU and tested SCR system and various sensors and the actual vehicle is identical, at this no longer to well known to a person skilled in the art that technology is further elaborated.
Data acquisition process equipment 15 is coupled to checkout equipment 13, is used for determining thawing time according to the testing result and the preassigned of checkout equipment.Alternatively, data acquisition process equipment 15 can also be coupled to ECU 14, is used for obtaining from ECU the duty of the parts of SCR system, the duty of urea pump for example, and the duty of nozzle, or the like.Alternatively, checkout equipment 13 can pass through ECU and indirect coupling with data acquisition process equipment 15.Data acquisition process equipment 15 can be computing machine, and perhaps any other has the data acquisition process equipment of data-handling capacity.When the signal data that data of handling when data acquisition process equipment 15 and ECU or checkout equipment provide was incompatible, data acquisition process equipment 15 can also comprise the function of conversion of signals.
Described thawing time can comprise the thawing time of urea box thawing time and/or electrical heating urea pipe.According to embodiment of the present utility model, above-mentioned different thawing time can be measured independently.The urea box thawing time can be measured under the prerequisite that assurance electrical heating urea pipe fully heats.And the thawing time of electrical heating urea pipe can be measured under the prerequisite that urea box thaws fully.
Particularly, the urea box thawing time can for example comprise preliminary thawing time, i.e. the time of thawing bottom the urea box and needing.As mentioned above, this can be measured as from the temperature control heating unit and begin to be heated to the time that urea liquid temperature the urea box arrives above-mentioned first threshold.Perhaps, this for example can be measured as from the temperature control heating unit and begin to be heated to the time that urea pump or nozzle reach the particular job state.
Alternatively, the urea box thawing time can also comprise abundant thawing time, and this for example can be measured as from the temperature control heating unit and begin to be heated to the time that temperature the urea box reaches above-mentioned second threshold value.Perhaps this abundant thawing time can be measured as from the temperature control heating unit and begin to be heated to the time that urea box thaws fully.And thawing fully of urea box for example can be observed by naked eyes.
The thawing time of electrical heating urea pipe for example can be measured as, and under the prerequisite that urea box fully thaws, reaches time of particular job state from beginning to be heated to urea pump or nozzle.For example, when urea pump enters the build-up pressure state, perhaps nozzle enters spray regime, can judge that urea pipe thaws successfully.
Above-mentioned thawing time all can be used as (comprising electrical heating urea pipe thawing time, each urea box thawing time) indication of the ability of thawing of SCR system, perhaps can select the indication of its maximal value as the ability of thawing of SCR system.
Should be appreciated that test macro shown in Figure 1 only is for the example explanation, rather than restrictive.It can comprise various distortion.For example, preferably, system 100 comprises that also the thermal medium pump is used to provide the circulation of thermal medium.Preferably, system 100 can also comprise that solenoid valve is used for realizing thermal medium round-robin break-make according to the control of ECU.Perhaps, preferably, system 100 can also comprise temperature and pressure transmitter, is used for detecting the temperature and pressure of thermal medium cyclic process.
Test macro 100 can have some test patterns.For example, under first test pattern, can test the thawing time of urea box, comprise the initial thawing time of urea box and the abundant thawing time of urea box.And, the thawing time of test urea pipe in second test pattern.
Under any test pattern, in order to simulate cold snap, system under test (SUT) generally is placed in the low temperature environment, for example can be placed in the low temperature chamber.And other equipment, for example temperature control heating unit, SCR aftertreatment ECU and data acquisition process equipment etc. can place the normal temperature chamber.Can not need to adopt special low temperature resistant temperature control heating unit, ECU and data acquisition process equipment etc. like this, to save cost.
In first test pattern, tested SCR system is set at the low temperature environment time enough, makes urea box icing fully; By the ECU data are set, urea pump, urea nozzle and urea pipe are arranged under the normal operating conditions.For example, can make urea pump in running order, satisfy other all injection conditions (for example NOx concentration in delivery temperature, urea level, urea pressure, the exhaust or the like) except that the urea box temperature by the control of ECU.And, can be in the heated condition time enough by ECU control electrical heating urea pipe in advance, so that urea pipe thaws.Under this test pattern, can get rid of other factors to measuring the influence of urea box thawing time.Then, measure beginning.Regulate temperature control heating unit 12 beginning heat hot media.Data acquisition process equipment will reach first threshold according to the temperature of the urea liquid that checkout equipment detected and judge that the urea box bottom thaws successfully, thereby determine the preliminary thawing time of urea box.Alternatively, data acquisition process equipment can also reach the second threshold decision urea box according to the temperature of the urea liquid that checkout equipment detected and fully thaw, thereby determines the abundant thawing time of urea box.
In second test pattern, tested SCR system is set at the low temperature environment time enough, makes urea pipe freeze.Urea box thaws in advance.Preferably, can regulate the temperature control heating unit and keep heating to urea box, urea liquid does not freeze in the urea box to keep.For example can be so that the temperature of urea liquid is higher than thaw point, as 0 ℃ or more than.Can also urea pump, urea nozzle be arranged under the normal operating conditions by ECU is set.Then, measure beginning.Control by ECU makes the electric heater unit of urea pipe be in heated condition.Data acquisition process equipment enters particular job state (for example urea pump enters the build-up pressure state, and perhaps nozzle enters spray regime) according to urea pump or nozzle and judges that urea pipe thaws successfully, thereby determines the thawing time of urea pipe.
Fig. 2 shows the block diagram according to the test macro 200 of a preferred embodiment of the present utility model.As shown in the figure, similar with Fig. 1, the test macro 200 of Fig. 2 comprises temperature control heating unit 12, checkout equipment 13, SCR aftertreatment ECU 14 and data acquisition process equipment 15.At this, for these with system 100 in identical component no longer further specify.
Be that with the different of Fig. 1 Fig. 2 has specifically illustrated each parts of equipment under test.This tested SCR system comprises urea box 3, urea pump 5, urea nozzle 7, urea pipe 16 and urea container 6.Described urea box has no source heat exchanger (representing with the U type of overstriking in the drawings), and described urea pipe has electric heater unit (representing by the coil on the pipeline 16).Urea container 6 is used to deposit the urea liquid of urea nozzle ejection.This urea container is not necessary, if when for example nozzle is installed to be facing to freeing port in the test cabinet etc., this urea container can be omitted.Urea pump 5, urea nozzle 6 and urea pipe 16 constitute the SCR spraying system, are used to simulate actual injection situation.One of urea box 3 is used to deposit aqueous solution of urea, and the direct tested object of the ability of thawing as test.With
Be also that with the different of Fig. 1 test macro 200 also comprises: flowmeter 8, solenoid valve 9, thermal medium pump 11, temperature and pressure transmitter 4 etc.Wherein flowmeter 8 is used for detecting the flow of thermal medium circulation, and it can be arranged in the one or more positions in the thermal medium circulation.Thermal medium pump 11 is used to provide the round-robin thermal medium.Solenoid valve 9 opens or closes under the control of ECU, to be used to control the break-make of water cycle.Should be appreciated that these parts only are exemplary, as top described with reference to figure 1, flowmeter, solenoid valve and temperature and pressure transmitter etc. are all not necessarily.
As shown in Figure 2, a part of parts of test macro are set at (frame of broken lines shown in mark among the figure 2 illustrates) in the low temperature environment, and another part parts are set at (frame of broken lines shown in mark among the figure 1 illustrates) under the normal temperature environment.Be set up with low temperature environment in parts mainly comprise tested SCR system, comprise urea box 3, pressure-temperature sensor 4, urea pump 5, urea container 6, urea nozzle 7 etc.Miscellaneous part then is under the normal temperature environment.Preferably, in test, low temperature environment and normal temperature environment need to isolate, to avoid influencing test result.
Similar with test macro 100, test macro 200 also has some test patterns, can test the heating efficiency of urea box and the heating efficiency of urea pipe independently.And because in the test macro 200, the thermal medium of temperature control heating unit cycles through solenoid valve and is connected with the heat exchanger of urea box.Therefore, can constantly open and close the test of carrying out repeatedly the course of defrosting of urea box repeatedly by control electromagnetic valve.Its test process of brief description, and similarly partly no longer describe in detail with test macro 100.Under low temperature environment, make urea box icing fully, by the control of ECU, make urea pump 5 in running order, satisfy other all injection conditions except that the urea temperature of urea box 3, and make thermal medium pump 11 (for example, water pump) in running order.Open solenoid valve 9 this moment, the urea liquid that the thermal medium after heating begins to circulate in the urea box heats.By temperature and pressure transmitter acquired signal constantly, then according to the thermal behavior of the signal controlling temperature control heating unit of gathering with simulated engine.When the temperature that detects urea liquid reaches first temperature, can judge that promptly the urea box bottom thaws successfully, thereby determine the preliminary thawing time of urea box.Alternatively, when reaching specific duty, urea pump or nozzle can judge that when detecting the urea box bottom thaws successfully.Then, can continue heating, detect the time that urea box fully thaws.Then, ECU can control electromagnetic valve close, and makes no longer urea box to be heated.At low temperatures the some time, urea box may freeze once more.The temperature of the urea box that detects according to checkout equipment 13, ECU can open solenoid valve once more and urea box be heated allowing.Thereby the beginning test of thawing again.Therefore, can simulate under the actual low temperature environment, urea box adds thermoelectrical magnetic valve and constantly opens the process of thawing repeatedly of closing.
In addition, the thawing condition that test macro 200 can also analog electrical heating urea pipeline is tested the thawing time of urea pipe.Test macro is placed the enough time under the low temperature, make urea pipe freeze.And by temperature control heating unit heating urea case, make it thaw fully in advance.Then, the control by ECU makes the electrical heating urea pipe be in heated condition.Whether enter particular job state (for example urea pump enters the build-up pressure state or nozzle enters spray regime) by detection urea pump or nozzle and judge whether urea pipe thaws.Thereby can determine the thawing time of urea pipe.
Fig. 3 shows the process flow diagram of method of testing 300 of the ability of thawing of urea liquid that is used for testing the SCR system according to an embodiment of the present utility model.This method 300 can realize to measure the thawing time of urea box by test macro shown in Figure 1 100 or test macro 200 shown in Figure 2.As shown in the figure, in preparation process S310, tested SCR system is arranged under the low temperature environment, makes urea box icing fully, and urea pump, urea nozzle and urea pipe are arranged under the normal operating conditions by ECU.Begin test then.In step S320, by regulating the thermal medium that 12 heating of temperature control heating unit provide to the heat exchanger of urea box, to provide heat by the urea liquid of thermal medium circulation in urea box.In step 330, detect the temperature of the urea liquid in the urea box.In step S340, determine the thawing time of urea box according to testing result and preassigned.Then, method 300 finishes.Should be appreciated that the order that illustrates of above-mentioned steps is not represented sequencing.In test process, step S320 and step S330 carry out simultaneously.And data acquisition process equipment can be in real time or collected testing result among the step S330 termly, and according to collected testing result execution in step S340.
In step S340, can measure different thawing times according to different standards, comprise preliminary thawing time of urea box and/or the abundant thawing time of urea box.As mentioned above, data acquisition process equipment can arrive first threshold according to the urea liquid temperature in the detected urea box and judge that the urea box bottom thaws successfully, thereby determines the preliminary thawing time of urea box.Perhaps, data acquisition process equipment can judge that the urea box bottom thaws successfully according to urea pump or nozzle arrival particular job state, thereby determines the preliminary thawing time of urea box.The preliminary thawing time of this urea box can be measured as and begin to be heated to urea box bottom from the temperature control heating unit and thaw the time that success continued.
As an alternative or supplement, data acquisition process equipment can reach second threshold value (for example, 0 ℃) according to the temperature of the urea liquid that is detected and judge that urea box fully thaws, thereby determines the abundant thawing time of urea box.The abundant thawing time of this urea box can be measured as from the temperature control heating unit and begin to be heated to the time that urea box fully thaws and continued.
In a preferred embodiment, step S320 in the method 300 further comprises by the temperature and pressure in the cyclic process of temperature and pressure transmitter detection thermal medium, and, regulate the temperature control heating unit with the thermal medium circulatory condition under the simulated engine actual motion according to the testing result of described temperature and pressure transmitter.
Fig. 4 shows the thaw method of testing 400 of ability of the urea liquid that is used for testing the SCR system according to another embodiment of the present utility model.This method 400 can realize to measure the thawing time of urea pipe by test macro shown in Figure 1 100 or test macro 200 shown in Figure 2.As shown in the figure, in preparation process S410, tested SCR system is arranged at low temperature environment, makes urea pipe freeze; Urea box is thawed in advance.By ECU urea pump, urea nozzle are arranged under the normal operating conditions simultaneously.Begin test then.In step S420, the control by ECU makes the electric heater unit of urea pipe be in heated condition.In step S430, detect the duty of urea pump or nozzle.And, in step S440, reach the particular job state according to urea pump or nozzle and judge that urea pipe thaws successfully, thereby determine the thawing time of urea pipe.For example, enter the build-up pressure state according to urea pump, perhaps nozzle enters spray regime, can judge that urea pipe thaws successfully.Then, method 400 finishes.Should be appreciated that the order that illustrates of above-mentioned steps is not represented sequencing.In test process, step S420 and step S430 carry out simultaneously.And data acquisition process equipment can be in real time or collected testing result among the step S430 termly, and according to collected testing result execution in step S440.
Embodiment of the present utility model provides more flexibly, accurately and can effective cost-effective urea box well heater and the method for testing and the device of the ability of thawing of electrical heating urea pipe.By replacing engine can realize the accurate adjusting of heating medium temperature, flow with the temperature control heating unit, solved in test process and to have used engine coolant to regulate the problem of difficulty as heating medium, and can be as far as possible near the true ruuning situation of engine.And the test macro according to embodiment of the present utility model is easy and simple to handle, flexible, can obviously save testing expenses again, and can test urea box well heater and electrical heating urea pipe respectively, has increased the means of testing of SCR after-treatment system sub-unit.Embodiment of the present utility model can be totally independent of engine pedestal operation, and is easy to operate and can monitor in real time the situation of inside heating, can evaluate and test more accurately urea box and urea pipe course of defrosting.
Though described the utility model, should be appreciated that the utility model is not limited to disclosed embodiment with reference to the embodiment of considering at present.On the contrary, the utility model is intended to contain the interior included various modifications and the equivalent arrangements of spirit and scope of claims.The scope of following claim meets broad interpretation, so that comprise all such modifications and equivalent structure and function.
Claims (6)
1. a urea liquid that is used for testing the SCR system test macro of ability that thaws, it is characterized in that, tested SCR system comprises urea box (3), urea pump (5), urea nozzle (7) and between urea box and the urea pump and the urea pipe between urea pump and the urea nozzle (16), described urea box (3) has no source heat exchanger, described urea pipe (16) has electric heater unit, it is characterized in that described test macro comprises:
Temperature control heating unit (12), the thermal medium that its heating provides to the heat exchanger of urea box, making provides heat by the urea liquid of thermal medium circulation in urea box,
SCR aftertreatment electronic control unit ECU (14), it controls the duty of tested SCR system and the electrical heating state of urea pipe,
Checkout equipment (13) comprises the temperature sensor of the temperature of the urea liquid that is used for detecting urea box,
Data acquisition process equipment (15) is coupled to checkout equipment and/or ECU, is used for determining thawing time according to the testing result and the preassigned of checkout equipment.
2. test macro according to claim 1, it is characterized in that, test macro is tested the thawing time of urea box under first test pattern, wherein in described first test pattern, tested SCR system is set at low temperature environment, make urea box freeze fully, and by ECU with urea pump, urea nozzle and urea pipe are arranged under the normal operating conditions, temperature control heating unit (12) heat hot medium wherein, data acquisition process equipment (15) reaches first threshold according to the temperature of the urea liquid that is detected and judges that the urea box bottom thaws successfully, thereby determine the preliminary thawing time of urea box, and/or data acquisition process equipment (15) reaches the second threshold decision urea box according to the temperature of the urea liquid that is detected and fully thaws, thereby determine the abundant thawing time of urea box.
3. test macro according to claim 1 and 2, it is characterized in that, test macro is tested the thawing time of urea pipe under second mode of operation, wherein in described second test pattern, tested SCR system is set at low temperature environment, make urea pipe fully freeze, urea box thaws in advance, and urea pump and urea nozzle are arranged under the normal operating conditions by ECU, control by ECU makes the electric heater unit of urea pipe be in heated condition, wherein data acquisition process equipment (15) reaches the particular job state according to urea pump or nozzle and judges that urea pipe thaws successfully, thereby determines the thawing time of urea pipe.
4. test macro according to claim 1 is characterized in that, also comprises: thermal medium pump (11), be arranged on the pipeline between temperature control heating unit and the urea box, and be used to provide the circulation of thermal medium.
5. according to claim 1 or 4 described test macros, it is characterized in that, also comprise: solenoid valve (9), be arranged on the pipeline between temperature control heating unit and the urea box, be used for realizing thermal medium round-robin break-make according to the control of ECU.
6. according to claim 1 or 4 described test macros, it is characterized in that, also comprise: temperature and pressure transmitter (4) is used for detecting the temperature and pressure of thermal medium cyclic process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206927530U CN201983933U (en) | 2010-12-31 | 2010-12-31 | System for testing thawing capability of SCR (selective catalytic reduction) system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010206927530U CN201983933U (en) | 2010-12-31 | 2010-12-31 | System for testing thawing capability of SCR (selective catalytic reduction) system |
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|---|---|
| CN201983933U true CN201983933U (en) | 2011-09-21 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010206927530U Expired - Lifetime CN201983933U (en) | 2010-12-31 | 2010-12-31 | System for testing thawing capability of SCR (selective catalytic reduction) system |
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| CN (1) | CN201983933U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102147335A (en) * | 2010-12-31 | 2011-08-10 | 潍柴动力股份有限公司 | Method for testing unfreezing capacity of SCR (semiconductor control rectifier) system and system therefor |
| CN102808680A (en) * | 2012-07-27 | 2012-12-05 | 潍柴动力股份有限公司 | Control method for SCR system low-temperature thawing |
| CN103513593A (en) * | 2013-10-08 | 2014-01-15 | 潍柴动力股份有限公司 | Method and device for achieving control in double-controller scene |
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| CN111706420A (en) * | 2020-06-24 | 2020-09-25 | 安徽康明斯动力有限公司 | Control method for unfreezing and heating states of urea box |
| CN112347618A (en) * | 2020-10-21 | 2021-02-09 | 潍柴动力股份有限公司 | Method and device for determining urea thawing efficiency and storage medium |
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2010
- 2010-12-31 CN CN2010206927530U patent/CN201983933U/en not_active Expired - Lifetime
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102147335A (en) * | 2010-12-31 | 2011-08-10 | 潍柴动力股份有限公司 | Method for testing unfreezing capacity of SCR (semiconductor control rectifier) system and system therefor |
| CN102147335B (en) * | 2010-12-31 | 2013-08-14 | 潍柴动力股份有限公司 | Method for testing unfreezing capacity of SCR (semiconductor control rectifier) system and system therefor |
| CN102808680A (en) * | 2012-07-27 | 2012-12-05 | 潍柴动力股份有限公司 | Control method for SCR system low-temperature thawing |
| CN103513593A (en) * | 2013-10-08 | 2014-01-15 | 潍柴动力股份有限公司 | Method and device for achieving control in double-controller scene |
| CN103513593B (en) * | 2013-10-08 | 2016-01-13 | 潍柴动力股份有限公司 | The method and apparatus controlled is realized in dual controller scene |
| EP3219946A4 (en) * | 2014-11-13 | 2018-07-04 | Isuzu Motors Limited | Urea water injection system and method for preventing crystallization in urea water injection device |
| US10450922B2 (en) | 2014-11-13 | 2019-10-22 | Isuzu Motors Limited | Urea water injection system and method for preventing crystallization in urea water injection device |
| CN111706420A (en) * | 2020-06-24 | 2020-09-25 | 安徽康明斯动力有限公司 | Control method for unfreezing and heating states of urea box |
| CN111706420B (en) * | 2020-06-24 | 2021-05-04 | 安徽康明斯动力有限公司 | Control method for unfreezing and heating states of urea box |
| CN112347618A (en) * | 2020-10-21 | 2021-02-09 | 潍柴动力股份有限公司 | Method and device for determining urea thawing efficiency and storage medium |
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