JPH0592412U - NOx reduction device - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To provide a NO _x reduction device capable of effectively reducing NO _x at low cost. [Composition] A humidity detector 10 for detecting the humidity in the air,
An arithmetic control unit 11 that compares the humidity X detected by the humidity detector 10 with a reference humidity and outputs a control command Z when the detected humidity X is lower than the reference humidity;
The pump 7 is driven by the control command Z from the pump motor 8 and the supply pipe 1 that supplies air to the supercharger that supplies combustion air to the engine. And a spray nozzle 5 for spraying the water supplied by the above into the air introduced into the supply pipe 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

The present invention relates to a NO _x reduction device for an engine such as a generator or an automobile, especially a diesel engine.

[0002]

[Prior Art]

Nitrogen oxides contained in the exhaust gas of an engine (hereinafter, referred to as NO _x) becomes a cause of air pollution, recently, regulation of the emissions is strongly demanded from the authorities.

A catalyst is generally used to reduce NO _x , but the catalyst has a problem of cost.

Therefore, by utilizing the phenomenon that the NO _x emission rate decreases as the combustion air humidity increases, a NO _x reduction device has been proposed that mixes steam into the air introduced into the combustion chamber in the cylinder. ing.

[0005]

[Problems to be solved by the device]

By the way, although NO _x is reduced as the humidity of the combustion air becomes higher due to the inclusion of steam, on the other hand, when the temperature of the combustion air becomes higher, the absolute amount of oxygen flowing into the cylinder decreases and the combustion state deteriorates. However, there is a problem that the output limitation will develop.

Therefore, the above conventional device has a problem that even if the humidity is increased by injecting steam, the temperature of the steam itself is high, so that NO _x cannot be effectively reduced as a result.

[0007] The present invention has been made based on such background, and an object thereof is to provide a NO _x reducing device can be effectively reduced in N O _x at a low cost.

[0008]

[Means for Solving the Problems]

 The purpose of the above is to compare the humidity detector that detects the humidity in the air with the humidity detected by the humidity detector and the reference humidity, and to output a control command when the detected humidity is lower than the reference humidity. It is installed in the middle of a control device, a pump driven via an actuator by a control command from the arithmetic and control unit, and a supply pipe that supplies air to a supercharger that supplies combustion air to the engine. And a spray nozzle for spraying the water supplied by the pump onto the air introduced into the supply pipe.

[0009] The above object is achieved by comparing the concentration of NO _x detector for detecting the concentration of NO _x in the exhaust gas from the engine, and the concentration of NO _x concentration of NO _x detected by the detector and the reference concentration of NO _x when the detected concentration of NO _x is higher than the reference concentration of NO _x, and the arithmetic and control unit which outputs a control command, a pump driven through the actuator by the control command from the arithmetic and control unit, the combustion air to the engine By means of a second means provided with a spray nozzle which is installed in the middle of a supply pipe for supplying air to a supercharger for supplying water and which sprays water supplied by a pump into the air introduced into the supply pipe. To be achieved.

[0010] The above object is achieved by comparing the concentration of NO _x detector for detecting the concentration of NO _x in the exhaust gas from the engine, and the concentration of NO _x concentration of NO _x detected by the detector and the reference concentration of NO _x , the detected concentration of NO _x is is higher than the reference concentration of NO _x, and the arithmetic and control unit which outputs a control command, a pump driven through the actuator by the control command from the arithmetic and control unit, installed in the room Air that is provided in the middle of a branch duct that is connected to open the inlet and outlet of the duct body that sends air from the outside to the vicinity of the engine, and that introduces the water that is fed by the pump into the branch duct. Spray nozzle, a fan provided in the middle of the branch duct and driven by an actuator according to a control command from the arithmetic and control unit, and a branch duct. The is achieved by the third means and a damper that opens through the actuator by the control command from at least the spray nozzle is disposed upstream or downstream side and the arithmetic control apparatus.

Further, the above-mentioned object is to compare a humidity detector for detecting humidity in the air with a humidity detected by the humidity detector and a reference humidity, and when the detected humidity is lower than the reference humidity, a control command is issued. , A pump driven via an actuator by a control command from the arithmetic and control unit, and an inlet and an outlet to a duct main body for supplying air from the outside to the engine installed in the room. A spray nozzle provided in the middle of the branch duct connected so as to open and spraying the water fed by the pump onto the air introduced into the branch duct; and the spray nozzle provided in the middle of the branch duct. Installed at least upstream or downstream of the fan driven by an actuator in response to a control command from the control unit and the spray nozzle provided in the branch duct. And a damper opened via an actuator according to a control command from the arithmetic and control unit.

[0012]

[Action]

 In the first means, when the humidity detected by the humidity detector is lower than the reference humidity, the pump is driven by the control command from the arithmetic and control unit, and water is supplied to the spray nozzle. This water is sprayed from the spray nozzle into the supply pipe. As a result, the air introduced into the supply pipe is sent to the supercharger in a moistened state.

[0013] In the second means, when the high Ri by reference density detected concentration of NO _x in concentration of NO _x detector, the pump is driven by a control command from the arithmetic and control unit, water is supplied to the Supurenozu Le It This water is sprayed from the spray nozzle into the supply pipe. As a result, the air introduced into the supply pipe is sent to the supercharger in a moistened state.

[0014] In the third means, when the high Ri by reference density detected concentration of NO _x in concentration of NO _x detector, the damper is opened with the pump and the fan is driven by a control command from the arithmetic and control unit , Water is supplied to the spray nozzle by the pump, while air is supplied to the branch duct by opening the damper. The water supplied to the spray nozzle is sprayed in the branch duct and moistens the air in the branch duct. This moistened air merges with the air in the duct body from the outlet of the branch duct, and is sent to the vicinity of the engine from the outlet of the duct body.

In the fourth means, when the humidity detected by the humidity detector is lower than the reference humidity, the pump and the fan are driven and the damper is opened by the control command from the arithmetic and control unit, and the spray is sprayed by the pump. Water is supplied to the nozzle, while air is supplied to the branch duct from the duct body by opening the damper. The water supplied to the spray nozzle is sprayed in the branch duct and moistens the air in the branch duct. This moistened air merges with the air in the duct body from the outlet of the branch duct, and is sent to the vicinity of the engine from the outlet of the duct body.

[0016]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a control conceptual diagram of the NO _x reduction device according to the first embodiment, and corresponds to claim 1.

In the figure, 1 is a supply pipe connected to a supercharger (not shown), 2 is a filter provided at one end of the supply pipe 1, and is a filter for removing dust in the air indicated by a, and 3 is the middle of the supply pipe 1. It is a water storage section provided on the lower surface of the.

One end of a pipe 4 is connected to the bottom of the water storage unit 3, and a plurality of spray nozzles 5 are provided at the other end of the pipe 4, and the spray nozzles 5 are provided from the upper part of the supply pipe 1. It is arranged so as to face the water reservoir 3.

A filter 6 and a circulation pump 7 are provided in the middle of the pipe 4, and the circulation pump 7 is operated by driving a pump motor 8 to pass the water in the water storage portion 3 through the pipe 4 to the spray nozzle. 5 is sprayed toward the inside of the supply pipe 1.

A humidity detector 10 detects the humidity of the atmosphere. Since the NO _x concentration has a correlation inversely proportional to the humidity as described above, the NO _x concentration can be controlled by detecting the humidity.

Reference numeral 11 denotes an arithmetic and control unit composed of, for example, a CPU, and compares the humidity X detected by the humidity detector 10 with a reference humidity X ₀ preset in the arithmetic and control unit 11, and ΔX = X When −X ₀ <0, that is, when the detected humidity X is lower than the reference humidity X ₀ , the control command Z is output to drive the pump motor 8. In the figure, 9 is a mist separator that removes mist from air sprayed with water, and 12 is a water supply system.

In the apparatus configured as described above, when the humidity X detected by the humidity detector 10 is lower than the reference humidity X ₀ , the arithmetic and control unit 11 issues the control command Z as described above. As a result, the pump motor 8 is driven and the circulation pump 7 operates. Then, as described above, the water in the water storage section 3 circulates and is sprayed from the spray nozzle 5, mixes with the air introduced from the filter 2 to give humidity to the air, and the air with high humidity becomes mist. The mist is removed by the separator 9 and is sent from the upper supply pipe 1 to an engine (not shown) through a supercharger. Therefore, only the humidity rises without raising the temperature in the combustion chamber of the engine, and NO _x in the exhaust gas can be reduced.

Although a part of the sprayed water is recovered again in the water storage unit 3, the water is gradually reduced as a whole, so that the water is appropriately replenished by the replenishment system 12.

FIG. 2 is a control conceptual diagram of the NO _x reduction device according to the second embodiment, which corresponds to claim 3. In this embodiment, parts which can be regarded as the same as those of the first embodiment shown in FIG.

In the figure, 21 is a duct main body which is installed indoors and whose front end is open to the room, 22 is a louver provided at its inlet, 23 is a silencer provided downstream of the louver 22 and downstream of the filter 39. , 24 is a first fan that is installed on the downstream side of the silencer 23 and is rotationally driven by a motor 25 to convey the air taken in from the outside in the direction of the arrow b. 1, a branch duct connected to the lower side of the duct main body 21 on the upstream side of the fan 24, 27 is a container provided in the middle of the branch duct 26, and the head 5a of the spray nozzle 5 is stored at the bottom 27a of the container 27. The spray nozzle 5 is arranged in the container 27 with a distance from the upper surface of the sprayed water so as to face upward.

In the branch duct 26, dampers 28 and 29 for opening and closing passages are provided on the upstream side and the downstream side of the container 27, and are driven by motors 30 and 31, respectively. A second fan 32 is provided at the inlet of the container 27 of the branch duct 26, and is driven by a motor 33.

In addition to the pump motor 8, the motors 30, 31, 33 are driven by a control command Z from the arithmetic and control unit 11. The motor 25 is driven by a separate system, and the first fan 24 is always rotated in the duct body 21 during operation.

Reference numeral 34 designates an engine operated by taking in air sent by the duct main body 21, 35 designates a generator driven by the engine 34, 36 designates a chimney for discharging exhaust gas from the engine 34, and 37 designates from the engine 34. is connected to the middle of a pipe 38 leading to the chimney 36, a concentration of NO _x detector for detecting the NO _x concentration in the exhaust gas through the tube 38.

In such a device, when the NO _x concentration Y detected by the NO _x concentration detector 37 is lower than the reference concentration Y _{0, the} dampers 28 and 29 are closed and the air is humidified. Instead, the air is introduced from the duct body 21 into the room, and the air introduced into the room is sent into the combustion chamber of the engine 34 through the filter 2 and the supercharger.

However, when the detected NO _x concentration Y becomes higher than the reference concentration Y ₀ , the arithmetic and control unit 11 issues a control command Z to the motors 30, 31, 33 as well as the pump motor 8. Then, the dampers 28 and 29 are opened, and the second fan 32 rotates, so that a part of the outside air flows into the branch duct 26. Here, as in the case of the outside air, water is directed upward from the spray nozzle 5. The air, which has been sprayed with water and has become humid due to water spray, is carried from the branch duct 26 into the duct main body 21, supplied from the duct main body 21 into the room, and finally sent into the combustion chamber of the engine 34. It increases the humidity of combustion gas and suppresses temperature rise. This reduces the amount of NO _x in the exhaust gas discharged from the chimney 36.

When the NOx removal device is not used, as a general NO _x reduction measure, there is a method of delaying the maximum combustion temperature from the standard fuel injection angle by a few degrees at the crank angle. In this case, the fuel consumption for obtaining the same output increases as the delay of the fuel injection angle from the standard increases.

However, in the present embodiment, since the humidity of the air is increased by spraying water and the temperature rise of the combustion gas is suppressed to reduce NO _x , the crank angle is not delayed so much, that is, the fuel injection timing is delayed. It is possible to inject fuel at a crank angle that is approximately 1 ° more advanced than the engine that has taken countermeasures, and as a result, it is possible to minimize output reduction. Specifically, fuel consumption reduction of 1.5 to 2 g / kWh can be expected.

In the embodiment of FIG. 1 of the present invention, the humidity of the air is detected, and in the embodiment of FIG. 2, the NO _x concentration in the exhaust gas is detected, but the embodiment of FIG. The NO _x concentration in the exhaust gas can be detected by the method (Claim 2), and the humidity of the air can be detected by the example of FIG. 2 (Claim 4). It goes without saying that various changes can be made without departing from the scope of the invention.

[0035]

[Effect of the device]

According to the invention of claim 1, when the humidity in the air is lower than the reference humidity, the air introduced into the supply pipe for feeding the air to the supercharger is sprayed with water, and the request is made. According to the invention described in 2, when the NO _x concentration in the exhaust gas from the engine is higher than the reference concentration, water is sprayed on the air introduced into the supply pipe that feeds the air to the supercharger. Therefore, NO _x can be efficiently reduced without increasing the exhaust gas temperature.

According to the third aspect of the present invention, when the NO _x concentration in the exhaust gas from the engine is higher than the reference concentration, the air introduced into the branch duct provided in the duct body for feeding the air near the engine By spraying water onto the air to increase the humidity of the air, and letting this air join the air of the duct body, and according to the invention of claim 4, when the humidity in the air is lower than the reference humidity, the vicinity of the engine The temperature of the exhaust gas is increased by spraying water to the air introduced into the branch duct that supplies air to the duct to increase the humidity of the air and then combining this air with the air in the duct body. Therefore, NO _x can be efficiently reduced.

[Brief description of drawings]

FIG. 1 is a control conceptual diagram of a NO _x reduction device according to a first embodiment of the present invention.

FIG. 2 is a control conceptual diagram of a NO _x reduction device according to a second embodiment of the present invention.

[Explanation of symbols]

1 Supply Pipe 3 Water Reservoir 4 Pipe 5 Spray Nozzle 7 Circulation Pump (Pump) 8 Pump Motor (Actuator) 10 Humidity Detector 11 Arithmetic and Control Unit 21 Duct Body 26 Branch Duct 28, 29 Damper 30, 31, 33 Actuator (Motor) 32 fan 34 engine 37 NO _x concentration detector X humidity X ₀ reference humidity Y NO _x concentration Y ₀ reference concentration Z control command

Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location F02M 25/02 P 7114-3G

Claims (4)

[Scope of utility model registration request] 1. A humidity detector for detecting humidity in air,
Comparing the humidity detected by the humidity detector and the reference humidity,
When the detected humidity is lower than the reference humidity, an arithmetic and control unit that outputs a control command, a pump that is driven via an actuator by a control command from the arithmetic and control unit, and an excess air that supplies combustion air to the engine. A NO _x reduction device comprising a spray nozzle installed in the middle of a supply pipe for supplying air to a feeder and spraying water supplied by a pump onto the air introduced into the supply pipe. 2. A concentration of NO _x detector for detecting the concentration of NO _x in the exhaust gas from the engine, it compares the said concentration of NO _x concentration of NO _x detected by the detector and the reference concentration of NO _x, is detected When the NO _x concentration is higher than the reference NO _x concentration, an arithmetic and control unit that outputs a control command, and a pump that is driven via an actuator by a control instruction from the arithmetic and control unit,
A spray nozzle installed in the middle of a supply pipe for supplying air to a supercharger for supplying combustion air to the engine and spraying water supplied by a pump onto the air introduced into the supply pipe. A NO _x reduction device characterized by the above. 3. A concentration of NO _x detector for detecting the concentration of NO _x in the exhaust gas from the engine, it compares the said concentration of NO _x concentration of NO _x detected by the detector and the reference concentration of NO _x, is detected When the NO _x concentration is higher than the reference NO _x concentration, an arithmetic and control unit that outputs a control command, and a pump that is driven via an actuator by a control instruction from the arithmetic and control unit,
The water supplied from the pump to the branch duct, which is provided in the middle of the branch duct connected to open the inlet and the outlet of the duct main body for feeding the air from the outside to the engine installed in the room The spray nozzle for spraying the introduced air, the fan provided in the middle of the branch duct and driven through the actuator by a control command from the arithmetic and control unit, and the spray nozzle provided in the branch duct A NO _x reduction device, characterized by comprising a damper installed on the upstream side or the downstream side and opened via an actuator in response to a control command from the arithmetic and control unit. 4. A humidity detector for detecting humidity in air,
Comparing the humidity detected by the humidity detector and the reference humidity,
When the detected humidity is lower than the reference humidity, an arithmetic and control unit that outputs a control command, a pump that is driven via an actuator by a control command from the arithmetic and control unit, and an engine installed in the room from the outside A spray nozzle that is provided in the middle of a branch duct connected to the main body of the duct that supplies the air so as to open an inlet and an outlet, and sprays water fed by the pump onto the air introduced into the branch duct. A fan that is provided in the middle of the branch duct and is driven via an actuator in accordance with a control command from the arithmetic and control unit; and a spray nozzle provided in the branch duct that is installed at least upstream or downstream of the spray nozzle; A NO _x reduction device comprising a damper that opens via an actuator according to a control command from the arithmetic and control unit.