Technical Field
The present invention relates to an exhaust gas analyzing system for analyzing
exhaust gas discharged from, for example, an internal combustion engine such as vehicle
5 engine and an external combustion engine such as steam turbine.
Background Art
An exhaust gas analyzing system of this type is as shown in Patent Literature 1 and
10 includes an introduction port for introducing exhaust gas, an exhaust gas flow path connected
0 to the introduction port, sampling pumps provided on the exhaust gas flow path, and analysis
parts provided on the exhaust gas flow path.
Then, the above exhaust gas analyzing system, in which periodic maintenance such
15 as replacement of sampling pump needs to be performed, is configured in the conventional
method to perform maintenance by determination of whether or not maintenance such as
replacement is required with the use of cumulative operating time of the sampling pumps or
according to predetermined a periodic maintenance period without taking cumulative
operating time into consideration.
20
However, as stated above, when maintenance such as replacement of sampling pump
is performed by using the predetermined cumulative operating time or maintenance period,
deterioration of the sampling pumps due to deterioration over time may have been already out
of a permissible range even before a lapse of the predetermined cumulative operating time or
25 maintenance period. This means a deteriorated sampling pump is used until the end of the
predetermined cumulative operating time or maintenance period, whereby causing sampling
performance degradation and therefore resulting in analysis performance degradation in the
analyzing system, which is problematic.
2
Meanwhile, even after a lapse of the predetermined cumulative time or maintenance
period, deterioration of the sampling pump may still within a permissible range. In this case,
maintenance such as replacement of usable sampling pump is performed according to a lapse
of the predetermined cumulative operating time or maintenance period and a problem arises
5 with necessity of suspending measurement for unnecessary maintenance.
Citation List
Patent Literature
10 [Patent Literature 11 JPA Hei 1 1-14530
1 Summary of Invention
I
Technical Problem
15 The present invention was achieved to solve the above problems all at once and has
an intended object to allow determination of appropriate maintenance timing of sampling
pumps in an exhaust gas analyzing system.
Solution to Problem
a 20
Specifically, an exhaust gas analyzing system according to the present invention is
characterized by including an introduction port for introducing exhaust gas, a main flow path
with one end connected to the introduction port, sampling pumps provided in the main flow
path in order to sample exhaust gas sent from the introduction part, analysis parts provided on
25 the upstream side or downstream side of the sampling pumps in the main flow path in order
to analyze exhaust gas, main flow meters provided on the upstream side or downstream side
of the analysis parts in the main flow path in order to confirm whether exhaust gas flows
through the analysis parts with a flow rate required for analysis, and pump abnormality
determination parts for determining abnormality of the sampling pumps by detecting whether
or not pump flow rates of the sampling pumps obtained by using output values of the main
5 flow meters meet predetermined conditions of abnormal functioning.
Here, for the determination of whether or not pump flow rates of the sampling
pumps meet predetermined conditions of abnormal functioning, it is considered to determine,
for example, whether or not pump flow rates fall in predetermined abnormal flow rates or less
a 10 or whether or not decrements of pump flow rates per unit time (i.e. inclination in time
fluctuation) fall in predetermined abnormal values or less.
In such a system, the pump abnormality determination parts determine abnormality
of the sampling pumps by detecting whether or not pump flow rates obtained by using output
15 values of the main flow meters meet predetermined conditions of abnormal functioning,
whereby deterioration of the sampling pumps can be objectively determined so as to
determine appropriate maintenance timing. Therefore, defects (such as sampling
performance degradation and unnecessary maintenance) of pump maintenance caused by
using predetermined cumulative time and maintenance period according to the conventional
@ 20 method can be resolved.
In order to enable appropriate exhaust gas measurement by showing a user the
tendency of fluctuations of pump flow rates obtained from output values of the main flow
meters and predicting time left before pump flow rates meet predetermined conditions of
25 abnormal functioning, the pump abnormality determination parts desirably show secular
change of pump flow rates of the sampling pumps in a graph on a display. This will be able
4
to improve usability for a user such that a user can predict time left before reaching abnormal
flow rates by looking at secular change of pump flow rates shown in a graph and select
measurement which can be made within the remaining time in order to carry out
measurement continuously.
5
It is desirable to fbrther include an upstream-side openinglclosing valve and
downstream-side openinglclosing valves provided on the upstream side and the downstream
side of the sampling pumps in the main flow path, exhaust flow paths connected between the
sampling pumps and the downstream-side openinglclosing valves in the main flow path,
e 10 exhaust flow meters provided in the exhaust flow paths in order to measure exhaust flow
rates in the exhaust flow paths, and a leakage abnormality determination part for checking
leakage with the use of the exhaust flow rates while closing the upstream-side
openinglclosing valve and the downstream-side openinglclosing valves and activating the
sampling pumps. This does not require a leakage check conducted in the conventional
15 method by causing gas for checking to flow so that gas for checking is no longer needed and
running costs can be cut. It is also possible to check leakage in the flow paths disposed
between the upstream-side openinglclosing valve and the downstream-side openinglclosing
valves by using the sampling pumps whose maintenance timing is appropriately determined.
* 20 The leakage abnormality determination part desirably determines leakage
abnormality in the main flow path by calculating leakage rates corresponding to ratio of
pump flow rates of the sampling pumps to the exhaust flow rates and comparing the leakage
rates to a predetermined abnormal leakage rate. By thus determining abnormal leakage
using leakage rates corresponding to ratio of exhaust gas flow rates to pump flow rates (=
25 "exhaust flow rate" / "pump flow rate"), it is possible to detect leakage which affects
measurement of exhaust gas.
Advantageous Effect of Invention
According to the present invention thus configured, it is possible to determine
appropriate maintenance timing for the sampling pumps in the exhaust gas analyzing system
5 and prevent sampling performance degradation and unnecessary maintenance.
Brief Description of Drawings
Fig.1 is a diagram typically showing a structure of an exhaust gas analyzing system
10 according to the present embodiment; and
0 Fig.2 is a diagram showing a graph display on a display in the same embodiment.
Description of Embodiments
One embodiment of exhaust gas analyzing system according to the present invention
15 is explained below referring to drawings.
An exhaust gas analyzing system 1 of the present embodiment has an exhaust gas
analyzing apparatus, which is provided in a test chamber in which an engine for vehicle or
the like not shown is installed, for analyzing exhaust gas emitted from the engine, and a
20 central management apparatus provided in a measurement chamber partitioned from the test • chamber. Then, the exhaust gas analyzing apparatus and the central management apparatus
send and receive various kinds of data such as analysis data and schedule data tolfrom each
other via, for example, LAN.
25 Note that a plurality of analyzers that are analysis parts based on, for example
different measurement principles is mounted on the exhaust gas analyzing apparatus and each
of the analyzers can measure a component such as HC, NO,, CO, and C02 included in
exhaust gas.
Specifically, the exhaust gas analyzing system 1 is, as shown in Fig. 1, provided with
an introduction port 2 for introducing exhaust gas emitted from the engine, and a main flow
5 path 3 with one end connected to the introduction port 2.
The main flow path 3 includes a heated exhaust gas flow path 3a in which exhaust
gas introduced from the introduction port 2 is heated and the heated exhaust gas is guided to
an exhaust gas analyzing apparatus of a heating type, and a normal-temperature exhaust gas
10 flow path 3b in which exhaust gas introduced from the introduction port 2 is guided to an
exhaust gas analyzing apparatus of a normal temperature type without heating.
Here, the heating-type exhaust gas analyzing apparatus 4 connected to the heated
exhaust gas flow path 3a includes, for example, THC meter (i.e. hydrogen flame ionization
15 detector or FID), whereas the normal-temperature-type exhaust gas analyzing apparatus 4
connected to the normal-temperature exhaust gas flow path 3b includes, for example, CO
meter (i.e. non-dispersive infrared analyzer or NDIR), COz meter (i.e. non-dispersive infrared
analyzer or NDIR), and NOx meter (i.e. chemiluminescence densitometer or CLD).
20 The heated exhaust gas flow path 3a and the normal-temperature exhaust gas flow
0 path 3b are formed by branching off on the downstream side of the introduction port 2. A
dust removal filter F1 for removing dust in exhaust gas is provided on the upstream side of
the branch point.
25 One or a plurality of analyzer(s) 4x for analyzing predetermined components in
heated exhaust gas is provided on the downstream side of the heated exhaust gas flow path 3a.
Note that Fig. 1 shows the case where two of the analyzers 4x are provided, and in the case a
plurality of analyzers 4x are provided, the heated exhaust gas flow path 3a branches off into
7
branch paths 3al and 3a2 each of which is provided with the analyzer 4x.
The heated exhaust gas flow path 3a is also provided with a sampling pump PI for
sampling exhaust gas sent from the introduction port 2 and introducing to the analyzers 4x.
5 The sampling pump PI allows exhaust gas to flow through the heated exhaust gas flow path
3a with a predetermined constant flow rate and is controlled by a controller 100.
On the upstream side of the sampling pump PI, a main flow meter FM1 such as
pressure-type flow meter is provided to measure the flow rate of exhaust gas flown by the
10 sampling pump P1 through the heated exhaust gas flow path 3a. There is also a flow rate
0 control valve CVl provided on the upstream side of the main flow meter FM1 in order to
control the flow rate of exhaust gas sampled in the sampling pump PI. In addition, in the
middle of the heated exhaust gas flow path 3a toward the analyzers 4x, a hot hose (not
shown) for heating exhaust gas at, for example about 130°C and other components are
15 installed. There is also a pressure control valve (not shown) provided on the downstream
side of the sampling pump P1 in order to control the pressure of exhaust gas flowing into the
analyzers 4x, and an exhaust flow path for pressure regulation (not shown) is connected to
discharge exhaust gas to the outside via the pressure control valve. Owing to the arrangement
of the main flow meter FM1 on the upstream side of the sampling pump PI in the present
20 embodiment, it is unnecessary to provide a flow meter in the exhaust flow path for pressure • regulation in order to obtain a pump flow rate.
On the downstream side of the normal-temperature exhaust gas flow path 3b, one or
a plurality of analyzer(s) 4x is provided in order to analyze predetermined components in
25 normal-temperature exhaust gas. Note that Fig. 1 shows the case where two of the analyzers
4x are provided, and in the case a plurality of analyzers 4x are provided, the
normal-temperature exhaust gas flow path 3b branches off into branch paths 3bl and 3b2
each of which is provided with the analyzer 4x.
8
The normal-temperature exhaust gas flow path 3b also includes a sampling pump P2
for sampling exhaust gas sent from the introduction port 2 and introducing to the analyzers 4x.
The sampling pump P2 allows exhaust gas to flow through the normal-temperature exhaust
5 gas flow path 3b with a predetermined constant flow rate and is controlled by the controller
100.
A flow rate control valve CV2 is provided on the upstream side of the sampling
pump P2 in order to control the flow rate of exhaust gas sampled in the sampling pump P2.
10 A filter F2 is further provided on the upstream side of the flow rate control valve CV2 in
e order to remove components such as moisture included in exhaust gas. Water removed by
the filter F2 is drained to the outside via a drain path 5. A cooling unit CU for cooling
exhaust gas is also provided on the downstream side of the sampling pump P2 and dew
condensation water generated in the cooling unit CU is also drained to the outside via a drain
15 path 6. Note that the drain path 6 is provided with a drain pump TP such as tubing pump.
The normal-temperature gas flow rate 3b includes main flow meters FM2 and FM3
such as thermal flow meters provided on the upstream side of the analyzers 4x in the branch
paths 3bl and 3b2, each of which has the analyzer 4x, in order to measure exhaust gas
20 flowing through the analyzers 4x, respectively. These main flow meters FM2 and FM3 are
a arranged in the inside of the normal-temperature-type exhaust gas analyzing apparatus 4.
Here, the arrangement in the inside of the exhaust gas analyzing apparatus 4 includes two
states one of which is to accommodate or hold various analyzers 4x within a single frame in
the exhaust gas analyzing apparatus 4 and the other one is to hold the analyzers 4x by means
25 of rack or the like. The normal-temperature exhaust gas flow path 3b is also provided with a
pressure control valve (not shown) on the upstream side of the main flow meters FM2 and
FM3 in order to control the pressure of exhaust gas flowing into the analyzers 4x, and an
exhaust flow path 7 for pressure regulation is connected for the pressure control valve to
9
discharge exhaust gas to the outside. The pressure control valve also prevents exhaust gas
fiom flowing through the analyzers 4x more than necessary. The exhaust flow path 7 for
pressure regulation is also provided with an exhaust flow meter FM4 such as thermal flow
meter for measuring an exhaust flow rate.
Thus, the exhaust gas analyzing system 1 of the present embodiment has a
maintenance check function for checking maintenance of the sampling pumps P1 and P2
provided in the heated exhaust gas flow path 3a and the normal-temperature exhaust gas flow
path 3b of the main flow path 3 respectively, and a leakage check function for checking
10 leakage in the heated exhaust gas flow path 3a and the normal-temperature exhaust gas flow
path 3b.
Firstly, the maintenance check function is explained.
15 The maintenance check function for the sampling pump PI provided in the heated
exhaust gas flow path 3a is composed of the main flow meter FMl provided on the upstream
side of the sampling pump P1 and a pump abnormality determination part 8a which
determines abnormality of the sampling pump PI by detecting whether or not a pump flow
rate of the sampling pump P1 obtained from an output value of the main flow meter FMI
20 meets a predetermined condition of abnormal functioning.
The pump abnormality determination part 8a is composed of the controller 100
which is made of a general-purpose or exclusive computer having CPU, internal memory,
inputloutput interface, AD converter, display and other components.
Specifically, the pump abnormality determination part 8a calculates a pump flow rate
in the sampling pump P1 with the use of an exhaust gas flow rate obtained by the main flow
meter FMl. The heated exhaust gas flow path 3a is configured such that the main flow
10
meter FMl is provided on the upstream side of the sampling pump P1 in one heated exhaust
gas flow path 3a, whereby an exhaust gas flow rate which is a value measured in the main
flow meter FMl corresponds to a pump flow rate of the sampling pump PI. Then, the pump
abnormality determination part 8a determines whether the sampling pump PI is abnormal by
5 comparing a pump flow rate of the sampling pump P1 to a predetermined abnormal flow rate.
Here, when a pump flow rate falls in a predetermined abnormal flow rate or less, the pump
flow rate meets a predetermined condition of abnormal functioning.
The predetermined abnormal flow rate in the present embodiment is set in two stages.
10 That is, there are two kinds of predetermined abnormal flow rates including a first abnormal
0 flow rate Qxl corresponding to a predetermined flow rate reduced from an initial flow rate of
exhaust gas flown by the sampling pump P1 through the heated exhaust gas flow path 3a, and
a second abnormal flow rate Qx2 corresponding to a predetermined flow rate reduced from
the first abnormal flow rate Qxl. The first abnormal flow rate Qxl indicates it is not the
15 maintenance timing of the sampling pump P1 yet but the maintenance period comes close
shortly. Meanwhile, the second abnormal flow rate Qx2 indicates the sampling pump P1
falls in the maintenance timing with a minimum flow rate required for the analyzers 4x.
Then, the pump abnormality determination part 8a notifies a user of precaution when
20 an exhaust gas flow rate obtained by the main flow meter FM1 is less than the first abnormal m flow rate Qxl. Therefore, the user can find out the maintenance timing of the sampling
pump PI is not far away. The pump abnormality determination part 8a also gives the user
an alarm when an exhaust gas flow rate obtained by the main flow meter FMl is less than the
second abnormal flow rate Qx2. Therefore, a user can find out the sampling pump P1 falls
25 in the maintenance timing.
The pump abnormality determination part 8a also shows a pump flow rate of the
sampling pump P1 in a graph on the display as shown in Fig. 2. At this time, a precaution
11
line L1 corresponding to the first abnormal flow rate Qxl and an alarm line L2 corresponding
to the second abnormal flow rate Qx2 are shown on the graph. By thus showing the trend of
fluctuations of a pump flow rate in the sampling pump P1 to a user in a graph, it is made
possible to predict time left before a pump flow rate reaches the abnormal flow rates (Qxl
5 and Qx2) and appropriately perform measurement of exhaust gas.
A maintenance check function for the sampling pump P2 provided in the
normal-temperature exhaust gas flow path 3b is composed of the plural main flow meters
FM2 and FM3 provided in the branch paths 3bl and 3b2 respectively on the downstream side
10 of the sampling pump P2, the exhaust flow meter FM4 provided in the exhaust flow path 7 m for pressure regulation, and a pump abnormality determination part 8b for determining
whether the sampling pump P2 is abnormal by detecting whether or not a pump flow rate of
the sampling pump P2 obtained from output values of the plural main flow meters FM2 and
FM3 and the exhaust flow meter FM4 meets a predetermined condition of abnormal
15 fbnctioning.
The pump abnormality determination part 8b is composed of the controller 100 in
the same manner as the pump abnormality determination part 8a of the heated exhaust gas
flow path 3a.
20
a Specifically, the pump abnormality determination part 8b calculates a pump flow
rate in the sampling pump P2 from exhaust gas flow rates obtained by the plural main flow
meters FM2 and FM3 and an exhaust flow rate obtained by the exhaust flow meter FM4.
More precisely, the pump abnormality determination part 8b calculates a total value by
25 adding exhaust gas flow rates obtained by the plural main flow meters FM2 and FM3 and an
exhaust flow rate obtained by the exhaust flow meter FM4 and use the total value as the
pump flow rate. Then, the pump abnormality determination part 8b determines whether the
sampling pump P2 is abnormal by comparing the pump flow rate to a predetermined
12
abnormal flow rate. Here, when the pump flow rate falls in the predetermined abnormal
flow rate or less, the pump flow rate meets a predetermined condition of abnormal
functioning. Note that the abnormality determination method in the pump abnormality
determination part 8b is the same as the pump abnormality determination part 8a.
5
Next, the leakage check function is explained.
In the leakage check fbnction of the present embodiment, a leakage check is
conducted for both the heated exhaust gas flow path 3a and the normal-temperature exhaust
10 gas flow path 3b simultaneously. Specifically, the leakage check function is composed of an
0 upstream-side openinglclosing valve V 1 and downstream-side openinglclosing valves V2 and
V3 provided on the upstream side and the downstream side of the sampling pumps P1 and P2
respectively in the main flow path 3, exhaust flow paths 9 and 10 connected between the
sampling pump PI and the downstream-side openinglclosing valve V2 and between the
15 sampling pump P2 and the downstream-side openinglclosing valve V3 respectively in the
main flow path 3, exhaust flow meters FM5 and FM6 provided in the exhaust flow paths 9
and 10 in order to measure flow rates in the exhaust flow paths 9 and 10 respectively, and a
leakage abnormality determination part 11 for checking leakage with the use of exhaust flow
rates obtained by the exhaust flow meters FM5 and FM6 while closing the upstream-side
20 openinglclosing valve Vl and the downstream-side openinglclosing valves V2 and V3 and rn activating the sampling pumps P1 and P2.
The upstream-side openinglclosing valve V1, which should be desirably arranged
close to the downstream side of the introduction port 2, is provided between the introduction
25 port 2 and the dust removal filter F1 on the upstream side of the branch point of the exhaust
gas flow paths 3a and 3b in the present embodiment. Note that the upstream-side
opening/closing valve Vl may also be provided in each of the exhaust gas flow paths 3a and
3b on the upstream side thereof. It should also be noted that the upstream-side
13
opening/closing valve V1 is a solenoid valve controlled by the controller 100.
The downstream-side opening/closing valve V2 of the heated exhaust gas flow path
3a is also provided between the sampling pump P1 and the branch point of the branch paths
5 3al and 3a2 in the heated exhaust gas flow path 3a. Meanwhile, the downstream-side
opening/closing valve V3 of the normal-temperature exhaust gas flow path 3b is provided
between the sampling pump P2 ,and the cooling unit CU in the normal-temperature exhaust
gas flow path 3b. Note that the downstream-side opening/closing valves V2 and V3 are
solenoid valves controlled by the controller 100.
Then, the exhaust flow path 9 of the heated exhaust gas flow path 3a is connected
between the sampling pump PI and the downstream-side opening/closing valve V2 in the
heated exhaust gas flow path 3a. The exhaust flow path 9 is provided with an
opening/closing valve V4 and the exhaust flow meter FM5 in this order. Meanwhile, the
15 exhaust flow path 10 of the normal-temperature exhaust gas flow path 3b is connected
between the sampling pump P2 and the downstream-side openingJclosing valve V3 in the
normal-temperature exhaust gas flow path 3b. The exhaust flow path 10 is provided with an
openinglclosing valve V5 and the exhaust flow meter FM6 in this order. Note that the
opening/closing valves V4 and V5 are solenoid valves controlled by the controller 100.
20
The leakage abnormality determination part 11 is composed of the controller 100
made of general-purpose or exclusive computer having CPU, internal memory, inputloutput
interface, AD converter, display and other components. Note that the leakage abnormality
determination part 11 may also be composed of a controller which is physically separated
25 from the controller 100 to constitute the pump abnormality determination parts 8a and 8b.
Specifically, the leakage abnormality determination part 11 causes, in a leakage
check process, the upstream-side opening/closing valve Vl and the downstream-side
14
openinglclosing valves V2 and V3 to close, and the opening/closing valves V4 and V5
provided in the exhaust flow paths 9 and 10 respectively to open. Then, the sampling
pumps P1 and P2 are activated to discharge gas from flow paths disposed between the
upstream-side opening/closing valve VI and the sampling pumps PI and P2. Then, output
5 values sent from the exhaust gas flow meters FM5 and FM6 at this time are obtained. Note
that an output value of the exhaust flow meter FM5 is zero when there is no leakage between
the upstream-side opening/closing valve V1 and the sampling pump P1 in the heated exhaust
gas flow path 3a. An output vale of the exhaust flow meter FM6 is also zero when there is
no leakage between the upstream-side openinglclosing valve V1 and the sampling pump P2
10 in the normal-temperature exhaust gas flow path 3b. The present embodiment is configured a to perform a leakage check on the upstream side of the sampling pumps P1 and P2 by the
leakage check function in measurement of exhaust gas because impact of leakage is more
significant on the upstream side of the sampling pumps PI and P2 that are accompanied by a
negative pressure.
15
The leakage abnormality determination part 11 also obtains, before the leakage
check process, an exhaust gas flow rate (i.e. pump flow rate on the heated side) in
measurement obtained by the main flow meter FMI in the heated exhaust gas flow path 3%
and a total value (i.e. pump flow rate on the normal temperature side) calculated by adding
20 exhaust gas flow rates in measurement obtained by the plural main flow meters FA42 and
FM3 and an exhaust flow rate in measurement obtained by the exhaust flow meter FM4 in the
normal-temperature exhaust gas flow path 3b.
Then, the leakage abnormality determination part 11 calculates, in the heated exhaust
25 gas flow path 3a, a leakage rate which is a ratio of a pump flow rate on the heated side to an
exhaust flow rate (or leakage flow rate) obtained by the exhaust flow meter FM5, and
determines leakage abnormality in the heated exhaust gas flow path 3a by comparing the
leakage rate to a predetermined abnormal leakage rate (e.g. 0.5%). The leakage abnormality
15
determination part 11 also calculates, in the normal-temperature exhaust gas flow path 3b, a
leakage rate which is a ratio of a pump flow rate on the normal-temperature side to an
exhaust flow rate (or leakage flow rate) obtained by the exhaust flow meter FM6, and
determines leakage abnormality in the normal-temperature exhaust gas flow path 3b by
5 comparing the leakage rate to a predetermined abnormal leakage rate (e.g. 0.5%).
When the leakage abnormality determination part 1 I thus determines leakage
abnormality in the heated exhaust gas flow path 3a or the normal-temperature exhaust gas
flow path 3b, a display to notifjr a user of leakage abnormality is shown on the display.
The reason why an output value of the main flow meter FMl is not used for an
exhaust flow rate (leakage rate) in a leakage check in the heated exhaust gas flow path 3a is
because the flow rate of exhaust gas belongs to a different flow rate range from the flow rate
of leakage and it is not possible to accurately measure a leakage flow rate in the main flow
15 meter FMl whose measurement range is large.
In the exhaust gas analyzing system 1 which is thus configured according to the
present embodiment, the pump abnormality determination parts 8a and 8b determine
abnormality of the sampling pumps P1 and P2 by calculating pump flow rates in the sampling
20 pumps PI and P2 with the use exhaust gas flow rates obtained by the main flow meters FM1,
FM2, and FM3 and comparing the pump flow rates to predetermined abnormal flow rates,
whereby making it possible to determine deterioration of the sampling pumps P1 and P2
objectively so as to determine appropriate maintenance timing. It is therefore possible to
resolve defects (such as sampling performance degradation and unnecessary maintenance) of
25 pump maintenance caused by using predetermined cumulative operation time and
maintenance period according to the conventional method. Also, because pump flow rates
are calculated by using output values of the main flow meters FM1, FM2 and FM3 for
measuring the flow rate of exhaust gas flowing through the analyzers 4x, it is unnecessary to
16
separately arrange a measurement instrument for measuring pump flow rates of the sampling
pumps P1 and P2 so that appropriate maintenance timing can be determined without making
the system structure complicated.
5 In addition, owing to the leakage abnormality determination part 11 which
determines abnormal leakage by using leakage rates corresponding to ratio of pump flow
rates to leakage flow rates (= "leakage flow rate" / "pump flow rate on the heated side" and
"leakage flow rate" / "pump flow rate on the normal temperature side"), leakage which
affects measurement of exhaust gas can be preferably detected.
10
m Note that the present invention is not limited to the above embodiment.
For example, as opposed to the configuration in the above embodiment in which one
main flow meter is provided on the upstream side of the sampling pump in the heated exhaust
15 gas flow path 3a, the main flow meter may be provided on the downstream side of the
sampling pump or a plurality of main flow meters may also be provided in a plurality of
brunch paths to which a plurality of analyzers is connected one by one.
Although the main flow path branches off into two paths including the heated
20 exhaust gas flow path and the normal-temperature gas flow path in the above embodiment,
0 the main flow path may also be provided as a heated exhaust gas flow path or a
normal-temperature exhaust gas flow path without branching off, or may also branch off into
more than two heated exhaust gas flow paths or more than two normal-temperature exhaust
gas flow paths.
25
Instead of showing pump flow rates of the sampling pumps in a graph on the display,
it may be configured, without displaying a graph, to notify a user of precaution when pump
flow rates fall in the first abnormal flow rate or less and give a user an alarm when pump
17
flow rates fall in the second abnormal flow rate or less.
The leakage function is not limited to calculate leakage rates to compare to
predetermined abnormal leakage rates, and may compare exhaust flow rates (leakage flow
5 rates) obtained from the exhaust flow meters to predetermined leakage flow rates
(thresholds).
Furthermore, the leakage check may be carried out by providing pressure sensors
between the upstream-side opening/closing valve and the sampling pumps and using pressure
10 values that are obtained by activating the sampling pumps while closing the upstream-side
• opening/closing valve.
In addition, although the leakage check is carried out for both the heated exhaust gas
flow path and the normal-temperature exhaust gas flow path simultaneously in the present
15 embodiment, it may be carried out for each of the exhaust gas flow paths. Leakage check
for both the heated exhaust gas flow path and the normal-temperature exhaust gas flow path
may also be carried out by closing the upstream-side opening/closing valve V1 and the
downstream-side opening/closing valves V2 and V3 and activating only the sampling pump
provided in one of the exhaust gas flow paths. For a leakage rate obtained at this time, for
20 example, a ratio (= "leakage flow rate" P'pump flow rate on the heated side" + "pump flow
a rate on the normal temperature side") of a leakage flow rate to a pump flow rate on the heated
side and a pump flow rate on the normal temperature side is considered.
The controller may also be provided with a necessary flow rate determination part in
25 which whether or not exhaust gas flows through the analyzers with a flow rate required for
measurement is determined by obtaining output values sent from the main flow meters.
The exhaust gas analyzing system may be provided with an introduction port for
18
introducing exhaust gas, a main flow path with one end connected to the introduction port,
sampling pumps provided in the main flow path in order to sample exhaust gas sent from the
introduction port, analysis parts provided on the upstream side or downstream side of the
sampling pumps in the main flow path in order to analyze exhaust gas, an upstream-side
5 opening/closing valve and downstream-side opening/closing valves provided on the upstream
side and the downstream side of the sampling pumps in the main flow path, exhaust flow
paths connected between the sampling pumps and the downstream-side opening/closing
valves in the main flow path, exhaust flow meters provided in the exhaust flow paths in order
to measure exhaust flow rates in the exhaust flow paths, and a leakage abnormality
10 determination part for checking leakage with the use of the exhaust flow rates while closing
the upstream-side openingtclosing valve and the downstream-side openinglclosing valves and
activating the sampling pumps. With this system, running costs can be cut because the
conventional leakage check conducted by causing gas for checking to flow is unnecessary
and therefore gas for checking is no longer needed. It is also possible to conduct a leakage
15 check in flow paths disposed between the upstream-side opening.closing valve and the
downstream-side openingJclosing valves by using the sampling pumps whose maintenance
timing is appropriately determined.
Although the above embodiment is provided for analyzing exhaust gas in the engine,
20 it may also be used for analyzing exhaust gas emitted &om an external combustion engine
a such as steam turbine.
In addition the above, the present invention is not limited to the above embodiment
and can also be modified variously in a range without deviating from the gist of the present
25 invention.
Reference Signs List
1 Exhaust gas analyzing system
19
2 Introduction port
3 Main flow path
4x Analyzer (Analysis part)
P 1, P2 Sampling pump
5 FMl, FM2, FM3 Main flow meter
V1 Upstream-side opening/closing valve
V2, V3 Downstream-side opening/closing valve
8% 8b Pump abnormality determination part
9, 10 Exhaust flow path
10 FMS,FM6 Exhaust flow meter
@ 11 Leakage abnormality determination part

CLAIMS
We claim :
1. An exhaust gas analyzing system (I) comprising:
5 an introduction port (2) for introducing exhaust gas;
a main flow path (3) with one end connected to the introduction port;
a sampling pump (PI, P2) provided in the main flow path in order to sample exhaust
gas sent from the introduction port;
an analysis parts (4x) provided on the upstream side or downstream side of the
10 sampling pump in the main flow path in order to analyze exhaust gas;
a main flow meter (FM1, FM2, FM3) provided on the upstream side or downstream
side of the analysis parts in the main flow path in order to confirm whether exhaust gas flows
through the analysis parts with a flow rate required for analysis; and
a pump abnormality determination part (8% 8b) for determining abnormality of the
15 sampling pump by detecting whether or not a pump flow rate of the sampling pump obtained
by using output values of the main flow meters meets predetermined conditions of abnormal
functioning.
2. The exhaust gas analyzing system as claimed in claim 1, wherein the pump
20 abnormality determination part shows secular change of the pump flow rate of the sampling
pump in a graph on a display.
3. The exhaust gas analyzing system as claimed in claim 1, comprising:
an upstream-side opening/closing valve (Vl) provided on the upstream side of the
25 sampling pump in the main flow path;
a downstream-side opening/closing valve (V2, V3) provided on the downstream side
of the sampling pump in the main flow path;
an exhaust flow path (9, 10) connected between the sampling pump and the
2 1
downstream-side opening/closing valve in the main flow path;
an exhaust flow meter (FM5, FM6) provided in the exhaust flow path in order to
measure an exhaust flow rate in the exhaust flow path; and
a leakage abnormality determination part (1 1) for checking leakage with the use of
5 the exhaust flow rate while closing the upstream-side openinglclosing valve and the
downstream-side openinglclosing valve and activating the sampling pump.
4. The exhaust gas analyzing system as claimed in claim 3, wherein the leakage
abnormality determination part determines leakage abnormality in the main flow path by
10 calculating a leakage rate corresponding to ratio of the pump flow rate of the sampling pump
a to the exhaust flow rate and comparing the leakage rate to a predetermined abnormal leakage
rate.