Technical Field
The present invention relates to an exhaust gas analyzing apparatus for measuring
exhaust gas discharged from an internal combustion engine of an automobile and the like.
5 The present invention also relates to an exhaust gas analyzing system for the internal
combustion engine and a method of operating the system, and is characterized by especially
an operation at start-up.
Background Art
To measure exhaust gas discharged from the internal combustion engine of the
automobile and the like, according to a conventional method, a vehicle mounted on a chassis
dynamo apparatus is travelled according to a predetermined travelling mode by an automatic
- operating robot, discharged exhaust gas is collected by a constant-volume sampling device,
15 and the collected sample gas is supplied to an exhaust gas analyzing apparatus equipped with
a plurality of different gas analyzers having different measurement principles, and is
measured for each component (Patent Literature I).
Each of the gas analyzers mounted in the exhaust gas analyzing apparatus includes
20 heating equipment such as a hot hose and a heater, and at measurement, a main body of the
gas analyzer and an exhaust gas introduction line are heated to respective analyzable
temperatures predetermined according to specifications.
However, it is unsuitable to heat them to the respective predetermined analyzable
25 temperatures during operations other than analysis in terms of costs. For this reason, the
conventional apparatuses are configured such that the heating state can be switched among
2
three following phases: (1) an "OFF mode" in which both the gas analyzer main body and the
exhaust gas introduction line are not heated, (2) a "pause mode" in which the gas analyzer
main body is regulated to have an analyzable temperature of about 191°C, and the exhaust
gas introduction line is regulated to have a predetermined intermediate temperature (about
5 100°C) that is lower than the analyzable temperature, and (3) a "standby mode" in which both
of the gas analyzer main body and the exhaust gas introduction line are regulated to have the
analyzable temperature.
However, from the viewpoint of the recent severe energy supply situation and
10 environmental load, it has been demanded to regulate the heating state more finely.
Nevertheless, once heating of the gas analyzer main body is stopped and its temperature
lowers, even when heating is restarted and the temperature returns to the initial value, it takes
time for the analyzer main body to be stably put into an analyzable state without any drift.
Specifically, when the heating state is switched from the "OFF mode" to the "standby mode",
15 it takes at least six hours to regain a stable state.
A plurality of analyzing units and an exhaust gas sampling line, which constitute the
exhaust gas analyzing system of the internal combustion engine, each are further equipped
with a temperature regulating mechanism formed of a hot hose, a heater, or the like, and at
20 analysis, temperatures of the analyzing units and the exhaust gas sampling line are kept to a
specified analyzing temperature (for example, about 19 1 "C) according to the specifications.
As described above, the specified analyzing temperature is substantially high, and it
takes a long time (for example, a few hours in the case of starting at normal temperatures) to
25 stably attain the specified analyzing temperature from a start of the operation of the
temperature regulating mechanism.
3
Some analyzing units such as a hydrogen flame ionization detector and a
chemiluminescent NO meter may require dedicated gas (analyzing gas) for analysis of the
exhaust gas. For example, to analyze the exhaust gas, the hydrogen flame ionization
5 detector requires hydrogen gas, and the chemiluminescent NO meter requires ozone gas.
In such analyzing units, in addition to temperature stabilization, for example,
stabilization of the flow rate of the analyzing gas and purge of inside remaining gas are
needed and thus, unless a predetermined time (for example, a few dozen minutes) elapses
a 10 from a start of the introduction of the analyzing gas, the stable analyzing operation cannot be
performed.
I Accordingly, to attain the state in which exhaust gas analysis can be immediately
I started (hereinafter referred to as standby mode), at least, it is necessary to operate the
15 temperature regulating mechanism in advance to attain the specified analyzing temperature,
and start the introduction of the analyzing gas to keep the analyzing units in the
stably-operable state.
Thus, conventionally, the operations of the temperature regulating mechanism and
20 the introduction of the analyzing gas are simultaneously started and then, proceed in parallel,
thereby reducing the time required to attain the standby mode.
For example, Patent Literature 2 describes a scheduler for automatically setting
operation timings of the exhaust gas analyzing apparatus and the dynamo, which are used in
25 an automobile test, to efficiently spend time for the test. When receiving a command of
standby mode from the scheduler, the exhaust gas analyzing apparatus starts the operation of
4
the temperature regulating mechanism and the introduction of the analyzing gas at the same
time.
However, since a temperature stabilizing time taken by the temperature regulating
5 mechanism is generally longer than a time that elapses before the analyzing units become
stably operable from the start of the introduction of the analyzing gas, during a time elapses
before the temperature becomes stable after the analyzing units become stably operable, the
analyzing units are in a waiting state in despite of the introduction of the analyzing gas,
uselessly consuming the analyzing gas.
a 10 Citation List
Patent Literature
[Patent Literature I] JPA 201 0-276473
[Patent Literature 21 JPA 2002-7 1 524
15
Summary of Invention
Technical Problem
Thus, the present invention intends to provide an exhaust gas analyzing apparatus
20 capable of achieving fiuther energy saving and rapidly starting analysis. The present
invention also provides an exhaust gas analyzing system capable of achieving hrther energy
saving.
Solution to Problem
25
That is, an exhaust gas analyzing apparatus according to a first aspect of the present
5
invention includes an analyzer main body for analyzing exhaust gas; an exhaust gas
introducing part for guiding the exhaust gas from an exhaust pipe passing the exhaust gas
therethrough to the analyzer main body; a heater for heating the analyzer main body and a
heater for heating the exhaust gas introducing part; and a temperature regulating mechanism
5 for controlling the heaters to regulate temperatures of the analyzer main body and the exhaust
gas introducing part, wherein a first mode which has the temperature regulating mechanism
regulate the temperatures of the analyzer main body and the exhaust gas introducing part to
an analyzable temperature that is a predetermined temperature allowing a start of analysis of
the exhaust gas, or a second mode which has the temperature regulating mechanism
0 10 regulate the temperature of the analyzer main body to the analyzable temperature and turning
off the heater for the exhaust gas introducing part can be selected. According to the present
invention, the term "OFF" means the substantial OFF state, and includes a state in which a
minute waiting current flows.
15 With such configuration, the temperature regulating mechanism can select the
second mode of regulating the temperature of the analyzer main body to the analyzable
temperature and turning off the heater for the exhaust gas introducing part. Therefore,
further energy saving can be achieved as compared to the conventional "pause mode". In
addition, by reheating the exhaust gas introducing part, the state can be rapidly shifted to the
20 analyzable state.
According to the present invention, a third mode which has the temperature
regulating mechanism regulate the temperature of the analyzer main body to the analyzable
temperature, and the exhaust gas introducing part to an intermediate temperature as a
25 predetermined temperature, the predetermined temperature being lower than the analyzable
temperature can krther be selected.
A fourth mode which has the temperature regulating mechanism turn off all of the
heaters can further be selected.
5 An exhaust gas analyzing system according to a second aspect of the present
invention includes one or more analyzing units for analyzing exhaust gas sampled from an
exhaust pipe of an internal combustion engine while using analyzing gas other than the
exhaust gas; and a temperature regulating mechanism for regulating a temperature of the
analyzing units andlor an exhaust gas sampling line, and prior to analysis of the exhaust gas,
a 10 introduction of the analyzing gas is started with a delay of predetermined time from the start
of the operation of the temperature regulating mechanism.
The start of the operation of the temperature regulating mechanism is not limited to
the start of the operation from power-on, and for example, includes the start of the
15 temperature regulating operation from a predetermined state where the intermediate
temperature is maintained toward a target stable temperature.
To minimize consumption of the analyzing gas and power consumption of the
I
temperature regulating mechanism prior to the standby mode, preferably, prior to the start of
/ 20 the analysis of the exhaust gas, the introduction of the analyzing gas is started with a delay of
predetermined time from the operation start time point of the temperature regulating
mechanism such that a temperature stabilizing time point as a time point when the
temperature regulated by the temperature regulating mechanism reaches a predetermined
stable temperature range for the first time after the start of the operation of the temperature
25 regulating mechanism substantially coincides with an analyzable time point as a time point
when the analyzing units can start stable analysis for the first time after the start of the
7
introduction of the analyzing gas.
A specific embodiment includes one or more analyzing units for analyzing exhaust
gas sampled from an exhaust pipe of an internal combustion engine while using analyzing
5 gas; a temperature regulating mechanism for regulating a temperature of the analyzing units
and/or an exhaust gas sampling line; a temperature stabilizing time point acquiring part for
acquiring a temperature stabilizing time point as a time point when the temperature regulated
by the temperature regulating mechanism reaches a predetermined stable temperature range
for the first time after the start of the operation of the temperature regulating mechanism; a
10 stable-operation required time storing part for storing a stable-operation required time as a
required time taken until the analyzing units are put into a predetermined stable state allowing
the units to start stable analysis for the first time after the start of introduction of the
analyzing gas; and a control part for, prior to the start of the exhaust gas analysis, operating
the temperature regulating mechanism, acquiring the temperature stabilizing time point from
15 the temperature stabilizing time point acquiring part, acquiring the stable-operation required
time from the stable-operation required time storing part, and calculating an introduction start
time point of the analyzing gas such that a stable-analysis enabling time point when the
analyzing units can start stable analysis for the first time after the start of the introduction of
the analyzing gas substantially coincides with the temperature stabilizing time point.
Specific examples of the analyzing units include a hydrogen flame ionization
detector using hydrogen gas as the analyzing gas and a chemiluminescent NO meter using
ozone as the analyzing gas.
25 The exhaust gas analyzing system according to the second aspect of the present
invention includes one or more analyzing units for analyzing exhaust gas sampled from an
8
exhaust pipe of an internal combustion engine while using analyzing gas; and a temperature
regulating mechanism for regulating a temperature of the analyzing units and/or an exhaust
gas sampling line, and prior to the start of the analysis of the exhaust gas, an operation start
time point of the temperature regulating mechanism and an introduction start time point of
5 the analyzing gas are set such that a temperature stabilizing time point as a time point when
the temperature regulated by the temperature regulating mechanism reaches a predetermined
stable temperature range for the first time after the start of the operation of the temperature
regulating mechanism substantially coincides with an analyzable time point as a time point
when the analyzing units can start stable analysis for the first time after the start of the
10 introduction of the analyzing gas.
With such configuration, in the case where the temperature stabilizing time obtained
by the temperature regulating mechanism is longer than time needed until the analyzing units
can start to stable operate after the start of the introduction of the analyzing gas and vice
15 versa, the operation start time point of the temperature regulating mechanism can be
substantially coincided with the introduction start time point of the analyzing gas, achieving
the same effect.
Advantageous Effects of Invention
According to the first aspect of the present invention, since further energy saving can
be achieved, and the temperature of the analyzer main body is kept at the analyzable
temperature at all times to maintain the analyzable state, analysis can be rapidly performed
merely by reheating the exhaust gas introducing part, resulting in efficient exhaust gas
I I 25 analysis.
According to the second aspect of the present invention, since time when the
analyzing units wait until the temperature becomes stabilized while the analyzing gas is
introduced can be shortened than conventional technique, consumption of the analyzing gas
can be reduced.
5
Brief Description of Drawings
Fig. 1 is a schematic overall view showing an exhaust gas analyzing system in
accordance with an embodiment of a first aspect of the present invention;
10 Fig. 2 is a fluid circuit diagram of a first measuring device (exhaust gas analyzing
apparatus) in the embodiment;
Fig. 3 is a table showing various heating modes in the embodiment;
Fig. 4 is a hnctional block diagram of a device controller and the first measuring
device (exhaust gas analyzing apparatus) in the embodiment;
15 Fig. 5 is an overall configuration view of an analyzing system of a second aspect of
the present invention;
Fig. 6 is a configuration principle view of the exhaust gas general analyzing
apparatus in the embodiment;
Fig. 7 is a configuration principle view of a chemiluminescent NO meter in the
20 embodiment;
Fig. 8 is a configuration principle view of a hydrogen flame ionization detector in
the embodiment;
Fig. 9 is a circuit configuration view of an information processor in the embodiment;
and
25 Fig. 10 is a timing chart showing an operation timing of temperature regulating
mechanism and the introduction of analyzing gas in the embodiment.
10
Description of Embodiments

5 An embodiment of the present invention will be described below with reference to
figures.
Fig. 1 schematically shows an entire exhaust gas analyzing system 1 in accordance
with this embodiment. The exhaust gas analyzing system 1, as shown in this figure,
includes a chassis dynamometer 2, an automatic driving device 3, a test automatic manager 5,
a plurality of exhaust gas measuring devices 4, and a device manager 6. A vehicle VH can
be travelled on the chassis dynamometer 2 in a pseudo manner, and performances of the
vehicle VH, such as fuel consumption and exhaust gas components, can be tested.
Each of the parts will be described below. The chassis dynamometer 2 includes a
uniaxial rotating drum 21, a motor and a flywheel (not shown) that apply loads on the
rotating drum 21, and a dynamo controller 22 for controlling them. The rotating drum 21
and the motor or the flywheel are placed in a pit below a floor F of a test chamber 10, and a
top of the rotating drum 21 is exposed from an opening formed on the floor F of the test
chamber 10. Driving wheels of the vehicle VH are located at test positions immediately
above the top of the rotating drum 21 such that the vehicle VH can travel as if it actually
travels. The dynamo controller 22 is accommodated in a measurement chamber provided,
for example, adjacent to the test chamber 10. The test chamber 10 and the measurement
chamber (and the pit) are collectively referred to as a cell.
The automatic driving device 3 includes a driving robot (not shown) that is mounted
in a cabin of the vehicle VH and drives an accelerator, a brake, and a clutch, and a robot
controller 31 that is connected to the driving robot and controls the driving robot, and the
automatic driving device 3 sends various command signals to the robot controller 3 1, thereby
controlling the driving robot to cause the vehicle VH to automatically travel in one or more
5 travelling modes such as a 10 mode and a LA mode. The robot controller 31 is
accommodated in, for example, the measurement chamber.
Though not described in detail, the test automatic manager 5 basically serves to set a
schedule of a travelling test. Examples of setting the schedule of the travelling test include
a 10 setting of a test mode and a test date, more detailed setting of vehicle behaviors such as
vehicle speed and engine rotating speed, and setting of a measurement target and
measurement timing. The test automatic manager 5 is provided with a communication port,
and the measuring devices 4, the chassis dynamometer 2, and the automatic driving device 3
are connected to the test automatic manager 5 so as to be intercommunicable in a wired or
15 wireless manner.
When the operator sets the schedule in this manner, the test automatic manager 5
appropriately transmits the command signal to the chassis dynamometer 2, the automatic
driving device 3, and the device manager 6 according to the schedule, and controls them such
20 that the test is made as scheduled.
Although one device manager 6 is connected to the test automatic manager 5 in Fig.
1, a plurality of device managers 6 may be connected to the test automatic manager 5. In
this case, the test automatic manager 5 can perform scheduling for each of the device
25 managers 6.
The exhaust gas measuring devices 4 (hereinafter also referred to merely measuring
devices 4) are devices used to measure the exhaust gas, and include, for example, a device
configured of one or more gas analyzers as unit equipment to measure exhaust gas
components, and a device such as a constant-volume sampling device that makes
5 pretreatment of measuring exhaust gas components.
In this embodiment, plural types of measuring devices 4 are adopted. For example,
a first measuring device 41 including a plurality of different gas analyzers having different
measurement principles, a second measuring device 42 as a constant-volume sampling device,
10 a third measuring device 43 as an EGR rate measuring device, and a fourth measuring device
44 as an ultrasonic flow rate meter are provided. Examples of the gas analyzer include an
FID for measuring THC, a CLD for measuring NOx, and an NDIR for measuring CO and
COz.
15 As shown in Fig. 2, the first measuring device 41 includes an analyzing part 412
including one or more types of gas analyzers S1, S2 and a sampling part 41 1 for sampling
exhaust gas from a sampling pipe connected to an exhaust pipe of the vehicle VH via an
exhaust gas introduction pipe L1, and the sampling part 41 1 is connected to the analyzing
part 412 via a connection pipe L2. The gas analyzers S1, S2 in Fig. 2 are hydrogen flame a 20 ionization detectors.
In the first measuring device 41, the exhaust gas introduction pipe L1 and the
connection pipe L2 are provided with hot hoses 413, 415 for heating the pipes to
predetermined temperatures, respectively, and the sampling part 41 1 and the analyzing part
25 412 are provided with heaters 4 14, 4 16, and 417 for heating their internal equipment and
internal flow paths to respective predetermined temperatures. In this embodiment, targets to
13
be heated are heated by the hot hoses 4 13, 4 15 and the heaters 4 14, 4 16, and 4 17 to about
19 1 "C as the analyzable temperature.
As shown in Fig. 3, the hot hoses 4 13, 41 5 and the heaters 4 14, 4 16, and 41 7 are
5 configured to be in one of four types of heating modes: an "OFF mode", a "sleep mode", a
"pause mode" and a "standby mode". In the "OFF mode", all of the hot hoses 4 13,4 15 and
the heaters 4 14,4 16, and 4 17 are not operated. In the "sleep mode", the heaters 4 16,4 17 for
the analyzing part 412 is regulated to have the analyzable temperature (about 191°C in this
embodiment), and the hot hoses 4 13,4 1 5 and the heater 4 14 for the sampling part 4 1 1 are not
10 operated. In the "pause mode", the heaters 4 16, 4 17 for the analyzing part 4 12 are regulated
to have the analyzable temperature, while the hot hoses 413, 415 and the heater 414 for the
sampling part 41 1 are regulated to have the predetermined intermediate temperature (about
100°C in this embodiment) that is lower than the analyzable temperature. In the "standby
mode", all of the hot hoses 4 13, 4 15 and the heaters 414, 4 16, and 4 17 are regulated to have
15 the analyzable temperature (about 19 1 "C in this embodiment).
Each of the devices 4 includes a sensor for measurement and a local computer
built-in, and the local computer functions as a calculating part for performing correction and
calibration of an output value from the sensor to calculate a measurement value indicating the a 20 amount of each component and for calculating the device performance value from the
measurement value, and a communicating part for transmitting the measurement value and
the device performance value, which are calculated by the calculating part, to the device
manager 6 according to a predetermined protocol.
25 The local computer further includes a mode control part 402 for receiving the
command signal from the device manager 6 and controlling an operation mode (measurement
14
mode, calibration mode, purge mode, etc.) and a status mode (sleep mode, standby mode,
etc.) of the exhaust gas measuring devices 4, a calibrating part for calibrating the sensor, or a
local storing part for storing device status information of the measuring devices 4 up to now,
such as pump pressure information indicating a suction pressure of a built-in pump,
5 sensitivity information related to the sensitivity of the sensor, accumulated operating time
information indicating accumulated operating time of each part, and inspection date
identifying information for identifLing a predetermined inspection time and date of the
measuring devices 4.
r) 10 As shown in Fig. 4, the local computer of the first measuring device 41 functions as
a device-side transmittinglreceiving part 401 and a mode control part 402.
The device manager 6 is configured by installing a predetermined program into, for
example, a general-purpose computer, and physically includes a CPU, a memory, a display,
15 an input means (keyboard, mouse, or the like) 64, and a communication interface. The CPU
and peripheral devices cooperate according to the program stored in the memory such that the
device manager 6 functions as a connection/disconnection monitoring part, a device indicator
display part and a device information acquiring part, as shown in Fig. 4, in this embodiment
as well as a transmittinglreceiving part 61, a heating mode data storing part 62, and a data
20 managing part 63. The device manager 6 is provided with a communication port, and the
measuring devices 4 are connected to the device manager 6 so as to be intercommunicable in
a wired or wireless manner.
Each part of the device manager 6 will be described below in detail.
25
The heating mode data storing part 62 is set in a predetermined area of the memory,
15
and stores heating mode data indicating the heating state of each gas analyzer. As shown in
Fig. 3, the heating mode data consists of four types of data (1) OFF mode data indicating that
all of the hot hoses 4 13, 4 15 and the heaters 4 14, 4 16, and 4 17 are not operated, (2) sleep
mode data indicating that the heaters 416, 41 7 for the analyzing part 412 are regulated to
5 have the analyzable temperature (about 19 1 "C in this embodiment), while the hot hoses 4 13,
415 and the heater 414 for the sampling part 41 1 are not operated, (3) pause mode data
indicating that the heaters 416, 417 for the analyzing part 412 are regulated to have the
analyzable temperature, while the hot hoses 41 3,415 and the heater 414 for the sampling part
41 1 are regulated to have the predetermined intermediate temperature (about 100°C in this
10 embodiment) that is lower than the analyzable temperature, and (4) standby mode data
indicating that all of the hot hoses 4 13,4 1 5 and the heaters 4 14,4 16, and 4 1 7 are regulated to
have the analyzable temperature (about 191°C in this embodiment).
The data managing part 63 manages various types of data. For example, the data
15 managing part 63 acquires the heating mode data selected by the operator or previously I
determined from the heating mode data storing part 62.
The transmittinglreceiving part 61 is formed of a communication interface, and
transmits the selected heating mode data to the first measuring device 41.
a 20
Next, a method of regulating the heating state of the first measuring device 41
having the above-mentioned configuration will be described.
First, the operator selects the heating mode on an initial screen (not shown)
25 displayed on the display of the device manager 6 by use of the input means 64. Then, the
data managing part 63 acquires the heating mode data selected by the operator from the
16
heating mode data storing part 62.
Then, the transmittinglreceiving part 61 transmits the heating mode data acquired
from the data managing part 63 to the first measuring device 4 1.
5
The first measuring device 41 receives the heating mode data transmitted from the
device-side transmittinglreceiving part 401, and the mode control part 402 controls ONIOFF
and temperatures of the hot hoses 4 1 3,4 15 and the heaters 4 14,4 16 and 4 17.
10 In this embodiment thus configured, by providing the sleep mode as the heating
mode, the hot hose 41 3 for the exhaust gas introduction pipe Ll, the hot hose 415 for the
connection pipe L2, and the heater 414 for the sampling part 411 can be stopped while
keeping the temperatures of the heaters 4 1 6, 4 1 7 for the analyzing part 4 12 to the analyzable
temperature. Therefore, further energy saving can be achieved as compared to the case of
15 using the conventional pause mode, and analysis can be rapidly performed by merely
reheating the hot hose 4 13 for the exhaust gas introduction pipe L 1, the hot hose 4 15 for the
connection pipe L2, and the heater 4 14 for the sampling part 4 1 1.
The first aspect of the present invention is not limited to the above-mentioned
20 embodiment.
In the embodiment, the heating mode data is stored in the device manager.
However, the heating mode data may be held in the first measuring device (exhaust gas
analyzing apparatus), and when the first measuring device is connected to the device manager,
25 the device manager may read the heating mode data.
In the embodiment, the hydrogen flame ionization detector is shown as an example
of the gas analyzer regulated to have the analyzable temperature in the sleep mode.
However, the gas analyzer may be a CLD-type NOx meter.
5 The first aspect of the present invention may be variously modified without
deviating from its subject matter.

Another embodiment of the present invention will be described below with respect
a 10 to figures.
As shown in Fig. 5, the exhaust gas analyzing system 10 in accordance with this
embodiment serves to sample the exhaust gas of the automobile internal combustion engine,
and analyze and calculate the component concentration and fuel consumption, and includes a
15 plurality of exhaust gas analyzing apparatuses 12 and an information processor 13 for
receiving and analyzing measurement data from each of the analyzing apparatuses 12 and
controlling the operation of each of the exhaust gas analyzing apparatuses 12 to manage the
apparatuses together.
20 Examples of the analyzing apparatuses 12 include a CVS apparatus and an EGR
measuring apparatus, or an exhaust gas general analyzing apparatus having plurality of
exhaust gas analyzing units 15, 16.
The exhaust gas general analyzing apparatus will be described herein in detail.
As shown in Fig. 6, the exhaust gas general analyzing apparatus includes an exhaust
18
gas sampling line 14 for sampling the exhaust gas, a plurality of analyzing units 15, 16 for
analyzing the exhaust gas introduced via the sampling line 14, and a temperature regulating
mechanism for keeping temperatures of the analyzing units 15, 16 and the sampling line 14 at
respective predetermined temperatures.
As the analyzing units 15, 16, the chemiluminescent nitrogen oxide analyzer 16
(hereinafter also referred to as chemiluminescent NO meter 16) and the hydrogen flame
ionization detector 15 are provided.
The chemiluminescent NO meter 16 measures the concentration of a nitrogen oxide
contained in the exhaust gas. Specifically, as shown in Fig. 7, all NOx contained in the
exhaust gas is converted into NO by an NO converter 161, and the NO is mixed with ozone
as analyzing gas emitted from an ozone generator 162 in a reaction tank 163 to generate
chemical reaction. A light detector (not shown) detects and outputs the intensity of light
generated through this reaction. In this embodiment, a path 16a for guiding the exhaust gas
to the reaction tank 163 through the NO converter 16 1 and a path 16b for guiding the exhaust
gas directly to the reaction tank 163 are provided in parallel. Then, by selectively guiding
the exhaust gas to the reaction tank 163 through either the path 16a or the path 16b by means
of a valve 165, the concentration of only NO contained in the exhaust gas, as well as the
concentration of NOx except for NO through taking a difference can be measured.
As shown in a principle view in Fig. 8, in the hydrogen flame ionization detector 15,
sampled exhaust gas is mixed with hydrogen gas as analyzing gas and supporting gas (air) at
a certain ratio, the mixture is burned in a combustion chamber (chimney) 15 1 in the presence
of an electric field, a current generated from ionized THC contained in the sample gas is
collected by a collector 152, the current is amplified by an amplifier 153, and the amplified
19
current is outputted. The amount (concentration) of THC can be calculated fiom the current
value.
As shown in Fig. 6, the temperature regulating mechanism (not shown) includes
5 heating means (not shown) such as a hot hose forming the sampling line 14 connecting the
analyzing units 15, 16 to the exhaust gas pipe and a heater for heating equipment in the
analyzing units 15, 16 and internal flow paths, and a heat-generation controller (not shown)
such as a thermistor for controlling the heating value of the heating means, and controls the
temperature of each target to be heated in the order of a thermometer TMl provided in the
a 10 sampling line and thermometers TM2 provided in the analyzing units 15, 16 by use of the
heat-generation controller.
The information processor 13 serves to manage the analyzing apparatuses 12 as
described above, and for example, in a state prior to the start of the analysis of the exhaust
15 gas, can control the temperature regulating mechanism to set the analyzing apparatuses 12 to
one of the heating modes: the "OFF mode", the "sleep mode", the "pause mode" and the
"standby mode". The "OFF mode" refers to a state where the temperature regulating
mechanism is not operated. The "sleep mode" refers to a state where main bodies (the
reaction tank 163 of the chemiluminescent NO meter 16 and the chimney1 5 1 of the hydrogen
20 flame ionization detector 15) of the analyzing units 15, 16 are regulated to have the specified
analyzing temperature (about 191 "C in this embodiment), while the temperatures of the hot
hose and the internal flow paths of sampling line 14 are not regulated. The "pause mode"
refers to a state where the main bodies of the analyzing units 15, 16 are regulated to have the
specified analyzing temperature (about 19 1 "C in this embodiment), and the hot hose and the
25 internal flow paths are regulated to have the predetermined intermediate temperature (about
100°C in this embodiment) that is lower than the specified analyzing temperature. The
20
"standby mode" refers to a state where the each part has the specified analyzing temperature
and the exhaust gas can be immediately analyzed.
In the above-mentioned standby mode, the information processor 13 operates the
5 temperature regulating mechanism, opens the predetermined valve so that the analyzing gas
is introduced into the analyzing units 15, 16.
Specifically, when receiving a command to switch the heating mode to the standby
mode from the operator or another apparatus, the information processor 13 starts to operate
a 10 the temperature regulating mechanism immediately or after a certain period of time, obtains a
required time taken until each part reaches a range of the specified analyzing temperature on
the basis of a value of the thermometer TMl, TM2, and after the start of operation, obtains a
temperature stabilizing time point that is a time point when the temperature regulated by the
temperature regulating mechanism reaches the range of the specified analyzing temperature
15 on the basis of the obtained required time, and starts to introduce the analyzing gas with a
delay of a predetermined time from an operation start time point of the temperature regulating
mechanism such that the temperature stabilizing time point substantially coincides with a
stable-analysis enabling time point that is a time point when the analyzing units 15, 16 can
start stable analysis after the start of the introduction of the analyzing gas.
Thus, as shown in Fig. 9, this information processor 13 has hnctions as a
temperature stabilizing time point acquiring part 13 1, a stable-operation required time storing
part 132, and a control part 133. These parts are acquired by operations of the CPU and
peripheral devices according to the predetermined program stored in the memory.
25
Next, the information processor 13 will be described below in detail while
2 1
describing the above-mentioned parts.
First, the control part 133 accepts the input of the standby mode command, and
causes the temperature regulating mechanism to be in the standby mode.
5
Next, using the start of the operation of the temperature regulating mechanism as a
trigger, the temperature stabilizing time point acquiring part 131 acquires the temperature
stabilizing time point that is the time point when the temperature regulated by the temperature
regulating mechanism reaches the range of the specified analyzing temperature from the
a 10 operation start time point on the basis of the value of the thermometer TMl, TM2.
Specifically, for example, the temperature stabilizing time that is the time point the
temperature reaches the range of the specified analyzing temperature is previously stored in
the memory for each temperature prior to the start of the operation, and the temperature
stabilizing time is added to the operation start time point of the temperature regulating
15 mechanism. The temperature stabilizing time stored in the memory is set to a value that
varies according to the mode immediately before the standby mode.
Meanwhile, the control part 133 acquires a stable-operation required time previously
stored in the stable-operation required time storing part 132 set in a predetermined area of the
20 memory, that is, a required time taken until the analyzing units 15, 16 are put into a
predetermined stable state in which the units can start stable analysis after the start of the
introduction of the analyzing gas. The stable state refers to a state where gas in cells of the
analyzing units is substituted and becomes stable.
25 Next, the control part 133 calculates an analyzing-gas introduction start time point
by subtracting the stable-operation required time from the temperature stabilizing time point,
22
and starts to introduce the analyzing gas at the calculated introduction start time point. The
analyzing units 15, 16 may be validated or activated at an appropriate timing.
As a result, as shown in Fig. 10, the stable-analysis enabling time point that is the
5 time point when the analyzing units 15, 16 can start stable analysis after the start of the
introduction of the analyzing gas coincides with the temperature stabilizing time point,
shifting to the standby mode at the time point (standby completion time point).
In this embodiment thus configured, there never causes the case where the analyzing
10 units 15, 16 is in the waiting state for temperature stabilization during the introduction of the
analyzing gas and conversely, where the stabilization of the analyzing units 15, 16 after the
introduction of the analyzing gas is waited in the temperature stable state. Therefore,
consumption of the analyzing gas as well as power consumption of the temperature
regulating mechanism before the standby state can be minimized.
15
The second aspect of the present invention is not limited to the embodiment.
For example, when there are the plural types of analyzing units 15, 16 as in the
embodiment, the operation of the temperature regulating mechanisms of the analyzing units
20 15, 16 may be started upon the receipt of the standby mode command. However, the
analyzing units 15, 16 may be different from each other in the temperature stabilizing time.
In this case, one of the analyzing units 15, 16 may wait for completion of standby of the other
of the analyzing units 15, 16, leading to energy loss. In such case, for example, the
temperature regulating mechanism of one of the analyzing units 15, 16 with a longer time
25 needed to achieve the standby mode may be operated first and with a delay of a certain period
of time, the temperature regulating mechanism of the other of the analyzing units 15, 16 may
23
be operated, such that the standby completion time points of the analyzing units 15, 16
coincide with each other.
The temperature stabilizing time point acquiring part 131 may calculate the
5 temperature stabilizing time point from a temperature rise curve obtained by means of the
temperature regulating mechanism.
Without the acquisition of the temperature stabilizing time point, for example, the
analyzing gas may be introduced when the temperature regulated by the temperature
10 regulating mechanism becomes a temperature that is lower than the specified analyzing
temperature by a predetermined temperature. In this case, through a prior test, the
predetermined temperature may be set such that a time elapsed until the predetermined
temperature reaches the specified analyzing temperature is substantially equal to the
stable-operation required time of the analyzing units 15, 16.
15
The stable-analysis enabling time point does not necessarily coincide with the
temperature stabilizing time point accurately. Indeed, in this manner, both the consumption
of the analyzing gas and the power consumption of the temperature regulating mechanism
can be minimized. However, even when the stable-analysis enabling time point is slightly
20 shifted fiom the temperature stabilizing time point, by at least introducing the analyzing gas
after the start of the operation of the temperature regulating mechanism and before the
temperature stabilizing time point, energy consumption can be reduced compared to that in
conventional simultaneous-start case.
25 In the case where the temperature stabilizing time obtained by the temperature
regulating mechanism is shorter than the stable-operation required time of the analyzing units
24
15, 16 from the introduction of the analyzing gas, the temperature regulating mechanism
operation start time point may be delayed from the analyzing-gas introduction start time
point.
5 The second aspect of the present invention is not limited to the embodiment, and
may be variously modified without deviating from its subject matter.
Reference Signs List
1 : exhaust gas analyzing system
S 1, S2: gas analyzer
L1: exhaust gas introduction pipe
L2: connection pipe
413,415: hot hose
414,416,417: heater
402: mode control part
10: exhaust gas analyzing system
12 1 : exhaust pipe
15, 16: analyzing units
14: exhaust gas sampling line
TM 1, TM2: thermometer
13 1 : temperature stabilizing time point acquiring part
132: stable-operation required time storing part
133: control part

CLAIMS
We claim:
1. An exhaust gas analyzing apparatus comprising:
5 an analyzer main body for analyzing exhaust gas;
an exhaust gas introducing part for guiding the exhaust gas from an exhaust pipe
passing the exhaust gas therethrough to the analyzer main body;
a heater for heating the analyzer main body and a heater for heating the exhaust gas
introducing part; and
a 10 a temperature regulating mechanism for controlling the heaters to regulate
temperatures of the analyzer main body and the exhaust gas introducing part, wherein
a first mode which has the temperature regulating mechanism regulates the
temperatures of the analyzer main body and the exhaust gas introducing part to an analyzable
temperature that is a predetermined temperature, thereby allowing a start of analysis of the
15 exhaust gas, or a second mode which has the temperature regulating mechanism regulates the
temperature of the analyzer main body to the analyzable temperature and turning off the
heater for the exhaust gas introducing part can be selected.
2. The exhaust gas analyzing apparatus as claimed in claim 1, wherein
0 20 a third mode which has the temperature regulating mechanism regulates the
temperature of the analyzer main body to the analyzable temperature, and the exhaust gas
introducing part to an intermediate temperature as a predetermined temperature, the
predetermined temperature being lower than the analyzable temperature can hrther be
selected.
25
3. The exhaust gas analyzing apparatus as claimed in claim 1, wherein
26
a fourth mode which has the temperature regulating mechanism turn off all of the
heaters can fbrther be selected.
4. An exhaust gas analyzing system comprising:
5 one or more analyzing units for analyzing exhaust gas sampled from an exhaust pipe
of an internal combustion engine while using analyzing gas; and
a temperature regulating mechanism for regulating a temperature of the analyzing
units and/or a exhaust gas sampling line, wherein
prior to analysis of the exhaust gas, introduction of the analyzing gas is
10 started with a delay of a predetermined time from a start of the operation of the temperature
regulating mechanism.
5. The exhaust gas analyzing system as claimed in claim 4, wherein
prior to the start of the analysis of the exhaust gas, the introduction of the analyzing
15 gas is started with the delay of the predetermined time from the operation start time point of
the temperature regulating mechanism such that a temperature stabilizing time point as a time
point when the temperature regulated by the temperature regulating mechanism reaches a
predetermined stable temperature range for the first time after the start of the operation of the
temperature regulating mechanism substantially coincides with an analyzable time point as a
8 20 time point when the analyzing units can start stable analysis for the first time after the start of
the introduction of the analyzing gas.
6. The exhaust gas analyzing system as claimed in claim 4, wherein
a hydrogen flame ionization detector using hydrogen gas as the analyzing gas and a
25 chemiluminescent NO meter using ozone as the analyzing gas are adopted as the analyzing
units.
7. An exhaust gas analyzing system comprising:
one or more analyzing units for analyzing exhaust gas sampled from an exhaust pipe
of an internal combustion engine while using analyzing gas;
a temperature regulating mechanism for regulating a temperature of the analyzing
units andlor an exhaust gas sampling line;
a temperature stabilizing time point acquiring part for acquiring a temperature
stabilizing time point as a time point when the temperature regulated by the temperature
regulating mechanism reaches a predetermined stable temperature range for the first time
after a start of the operation of the temperature regulating mechanism;
a stable-operation required time storing part for storing a stable-operation required
time as a required time taken until the analyzing units are put into a predetermined stable
state allowing the units to start stable analysis for the first time after a start of introduction of
the analyzing gas; and
a control part for, prior to start of the exhaust gas, operating the temperature
regulating mechanism, acquiring the temperature stabilizing time point from the temperature
stabilizing time point acquiring part, acquiring the stable-operation required time from the
stable-operation required time storing part, and calculating an introduction start time point of
the analyzing gas such that a stable-analysis enabling time point when the analyzing units can
start stable analysis for the first time after the start of the introduction of the analyzing gas
substantially coincides with the temperature stabilizing time point.
8. A method of operating an exhaust gas analyzing system comprising one or more
analyzing units for analyzing exhaust gas sampled from an exhaust pipe of an internal
combustion engine while using analyzing gas; and
a temperature regulating mechanism for regulating a temperature of the analyzing
28
units andor an exhaust gas sampling line, wherein
prior to a start of analysis of exhaust gas, introduction of the analyzing gas is started
with a delay of a predetermined time from a start of the operation of the temperature
regulating mechanism.
5
9. An exhaust gas analyzing system comprising:
one or more analyzing units for analyzing exhaust gas sampled from an exhaust pipe
of an internal combustion engine while using analyzing gas; and
a temperature regulating mechanism for regulating a temperature of the analyzing
a 10 units andor an exhaust gas sampling line, wherein
prior to the start of the analysis of the exhaust gas, an operation start time point of
the temperature regulating mechanism and an introduction start time point of the analyzing
gas are set such that a temperature stabilizing time point as a time point when the temperature
regulated by the temperature regulating mechanism reaches a predetermined stable
15 temperature range for the first time after the start of the operation of the temperature
regulating mechanism substantially coincides with an analyzable time point as a time point
when the analyzing units can start stable analysis for the first time after the start of the
introduction of the analyzing gas.