JPH0346750B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an exhaust gas treatment device for neutralizing exhaust gas from an engine using petroleum fuel containing sulfur.

(Prior Art) FIG. 3 shows a conventional engine-driven air conditioner Z ₀ using a gas engine 101 as a power source. This air conditioner Z ₀ has an indoor heat exchanger 107
outdoor unit X ₀ with outdoor heat exchanger 1
It consists of two units: an outdoor unit _Y0 with 10 units.

The outdoor unit X ₀ has a casing 116 separated by a partition plate 119 into two upper and lower chambers, that is, a heat exchange chamber 117 located above the partition plate 119 and a heat exchange chamber 117 located above the partition plate 119 .
The heat exchanger chamber 117 is divided into two chambers, an engine chamber 118 located below 9, and an outdoor unit 107, an outdoor fan 113, a four-way valve 105, an accumulator 106, an outdoor solenoid valve 108, and an outdoor expansion valve are installed in the heat exchange chamber 117. 109 and a cooling water pump 122, and a gas engine 101 and a compressor 104 driven by the gas engine 101 are installed in the engine room 118.
and an exhaust heat exchanger 102 and an exhaust muffler 103 connected to the exhaust port of the gas engine 101, respectively. Further, the exhaust pipe 134 of the exhaust silencer 103 includes a tail pipe 1 that passes through the heat exchanger chamber 117 in the vertical direction through the inside of the outdoor heat exchanger 107.
29 is installed. Further, the exhaust heat exchanger 102 is connected to a separately installed hot water tank 121 via a cooling water pipe 123.

On the other hand, indoor unit Y ₀ has indoor heat exchanger 1.
10, indoor fan 115, and indoor solenoid valve 111
and an indoor expansion valve 112.

This air conditioner Z ₀ performs a heating operation or a cooling operation by driving a compressor 104 with a gas engine 101. Now this air conditioner Z ₀
To briefly explain the operation of the refrigerant, taking heating operation as an example, during heating operation, the high temperature and high pressure refrigerant gas compressed in the compressor 104 passes through the four-way valve 105 and reaches the indoor unit _Y0 . It condenses in the indoor heat exchanger 110 of ₀ , generates condensation heat, and performs a predetermined heating effect. Indoor heat exchanger 1
The liquid refrigerant condensed at 10 is transferred to the indoor expansion valve 1
12 to the _indoor heat exchanger 107 of the outdoor unit and returns to the compressor 104 for a series of heating cycles.

On the other hand, exhaust gas discharged from the gas engine 101 during operation of the gas engine 101 passes from the exhaust heat exchanger 102 to the exhaust muffler 103 and is discharged to the outside from the tail pipe 129. At this time, the high-temperature exhaust gas discharged from the gas engine 101 exchanges heat with engine cooling water in the exhaust heat exchanger 102, and then gradually expands and compresses in the exhaust silencer 103. The gas temperature is lowered, and in particular, the tail pipe 129 is further cooled because the atmospheric temperature is low (in winter) and an endothermic action (evaporation action) takes place in the outdoor heat exchanger 107. Therefore, the water vapor contained in the exhaust gas is removed from the exhaust heat exchanger 10.
2. The condensed water is condensed in the exhaust muffler 103 and the tail pipe 129, and is discharged to the outside through the first drain pipe 125 and the second drain pipe 124, and the exhaust gas is discharged to the outside from the tail pipe 129. Ru.

However, in this way, the exhaust heat exchanger 102, the exhaust silencer 103, and the tail pipe 129 are connected in series,
Moreover, in an exhaust system in which the exhaust muffler 103 and the tail pipe 129 are arranged upward, the exhaust muffler 103
Since the flow in the tail pipe 129 becomes a downward flow, the communication pipes 132 and 13 inside the exhaust silencer 103
3 lower end portions 132a, 133a and throttle passage 135
A, 135B, 135C, the exhaust silencer 1
The exhaust gas flow blowing upward through the inside of 03 collides with the condensed water flowing downward, producing unpleasant low-frequency sounds such as gurgling (increase in noise).

On the other hand, according to experiments conducted by the present inventors, it has been confirmed that by removing the tail pipe 129, which has a large condensing effect, the amount of condensation is drastically reduced, and the low-frequency sound from the exhaust system is accordingly reduced. For example, engine speed N = 2000 rpm, heated room (number of indoor units)
Noise level and tail pipe 129 when the tail pipe 129 is installed under the conditions of n = 2 and outside temperature T = 7°C
What is the noise level when the outdoor unit is removed?
When measured at a position 1m in front of X ₀ , tail pipe 1
The noise level, which was 55.5 dB when the tail pipe 129 was installed, was reduced to 54 dB by removing the tail pipe 129. Therefore, it can be said that in order to reduce engine exhaust noise, the tail pipe 129 may be removed.

However, when the tail pipe 129 is removed, the exhaust gas is directly discharged from the exhaust muffler 103 into the heat exchanger chamber 117, which is made of acid-sensitive materials such as aluminum, copper, or iron. Since the outdoor heat exchanger 107, the fan drive motor 114, or the casing 116 are directly exposed to water vapor in the exhaust gas or water droplets (condensed water) due to dew condensation of the water vapor, there is a risk that each of these devices will be corroded and damaged. That is, petroleum fuels such as natural gas and light oil contain sulfur, and in particular, sulfur-based odorants are added to natural gas for gas leak detection. Therefore, when fuel such as natural gas containing sulfur is combusted, strong acidic substances such as sulfuric acid or hydrochloric acid are produced by the reaction between the sulfur-based substances in the fuel and water, and as a result, the moisture in the exhaust gas ( Water vapor) exhibits strong acidity with a pH of approximately 3 to 4 (in the case of natural gas).

The above-mentioned problems caused by condensation of water vapor in the exhaust gas occur when the air conditioner Z ₀ is operated in heating mode, in other words, when the outside temperature is low, such as in winter, and when the air conditioner is operated in cooling mode. In other words, it hardly occurs when the outside temperature is high, such as in summer.

Note that the water in the hot water tank 121 is combined with the combustion heat recovered by the gas engine 101 and the exhaust heat exchanger 10.
It is heated by the exhaust heat recovered in step 2.

(Object of the Invention) In view of the problems of conventional exhaust gas treatment devices as described above, the present invention aims to suppress corrosion damage to equipment as much as possible and improve its durability by neutralizing exhaust gas. The present invention has been developed for the purpose of providing an exhaust gas treatment device that reduces exhaust noise by suppressing the generation of low-frequency sounds caused by collision between condensed water and exhaust gas flow.

(Structure of the Invention) The exhaust gas treatment device of the present invention includes a neutralizing agent that acts to neutralize exhaust gas by contacting the exhaust gas in a treatment chamber having an exhaust inlet and an exhaust outlet. A mixture layer and a thermal conductor layer made of a suitable thermal conductor are arranged in a multilayered manner in the flow direction of the exhaust gas, and a drainage is provided at the bottom of the processing chamber for discharging condensed water condensed in the processing chamber. It is characterized by the formation of a mouth.

(Example) Hereinafter, the case where the exhaust gas treatment device of the present invention is applied to the exhaust system of a gas engine of a gas engine-driven air conditioner will be explained as an example. The overall system diagram of Z is shown. This air conditioner Z has almost the same overall structure as the conventional air conditioner Z ₀ (see Fig. 3), which differs only in a part of the exhaust system. For parts, only briefly explain the parts and avoid overlapping explanations.

In FIG. 1, the symbol X is an outdoor unit, and the symbol Y is an indoor unit. The outdoor unit X and the indoor unit Y constitute an air conditioner Z. or,
Reference numeral 1 is a gas engine for driving the compressor 4, 2 is an exhaust heat exchanger, 3 is an exhaust silencer, 5 is a four-way valve, 6 is an accumulator, 7 is an outdoor unit, 8 is an outdoor solenoid valve, and 9 is an indoor unit. 1 is an outer expansion valve; 10 is an indoor heat exchanger; 11 is an indoor solenoid valve; 12 is an indoor expansion valve; 13 is an outdoor fan; 14 is a fan motor;
5 is an indoor fan, 16 is a casing of outdoor unit
7 and a bulkhead plate that partitions the engine compartment 18, 21 is a hot water tank, 22 is a cooling water pump, 23 is a cooling water pipe, 24 is a first discharge pipe for discharging condensed water in the exhaust heat exchanger 2, 25 is an exhaust silencer This is a second drain pipe for discharging condensed water in the vessel 3.

An exhaust gas treatment device 40 according to an embodiment of the present invention is attached to an exhaust pipe 34 that projects upward from the exhaust muffler 3. This exhaust gas treatment device 40
As shown in an enlarged view in FIG. 2, there is an outer case 41 in the shape of a closed container, and a cylindrical container with a bottom that is fitted into the outer case 41 and forms a substantially annular closed space 44 between the outer case 41 and the outer case 41. Processing case 47 consisting of inner case 42
(The closed space 4 inside this processing case 47
4 is a processing chamber for the exhaust gas G, and in the following description, this closed space 44 will be referred to as the processing chamber 44.
). The outer case 41 has a lower outer peripheral surface 41
Exhaust outlets 4 of appropriate size are arranged at equal intervals in the circumferential direction at a.
3, 43..., and a drain port 46 of an appropriate diameter is formed on the bottom surface 41b, respectively. Also, the inner case 42
A large number of exhaust gas inlet ports 45, 45, . This processing case 47 is attached to the mounting bolt 49 with the inner case 42 fitted to the outside of the exhaust pipe 34 of the exhaust silencer 3.
It is fixed by Therefore, the exhaust gas G discharged from the exhaust silencer 3 flows into the processing chamber 44 through the exhaust gas inlet ports 45, 45... of the inner case 42, and then crosses the processing chamber 44 in the radial direction. while flowing down, and is discharged to the outside from the exhaust ports 43, 43, . . . of the outer case 41.

Furthermore, inside the processing chamber 44, a cylindrical inner thermal conductor layer 52 filled with a stainless wire mesh is arranged from the inner peripheral surface side to the outer peripheral surface side of the processing chamber 44 so as to cross the flow of the exhaust gas G. A cylindrical neutralizing agent layer 51 filled with magnesium and a cylindrical outer heat conductor layer 53 filled with a stainless wire mesh are laminated in three layers. Note that the degree of filling of the stainless wire mesh in the inner thermal conductor layer 52 and the outer thermal conductor layer 53 is set so that the flow resistance of exhaust gas can be suppressed to a predetermined value or less.

Further, the drain port 46 formed on the bottom surface 41b of the processing case 47 is directly communicated with the outside via the third drain pipe 26 without passing through the inside of the exhaust silencer 3.

When the exhaust gas treatment device 40 configured as described above is attached to the exhaust pipe 34 of the exhaust muffler 3, the exhaust gas G discharged from the exhaust muffler 3 flows into the processing chamber 44 from the exhaust gas inlets 45, 45... After flowing into the exhaust gas G, it is discharged to the outside from the exhaust outlets 43, 43, . Since it is cooled by the styrene wire mesh 53, the water vapor contained in the exhaust gas G is sequentially condensed in each of the heat conductor layers 52 and 53, and at the same time comes into contact with the magnesium in the neutralizer layer 51. The strongly acidic water is neutralized and becomes neutral condensed water W, which is discharged from the drain port 46 through the third drain pipe 26 to the outside. Therefore, the exhaust outlets 43, 43...
The exhaust gas G discharged to the outside through the heat exchanger chamber 17 contains almost no water vapor containing sulfur components, and therefore the exhaust gas G is discharged from the heat exchanger chamber 17 to the outdoor side. Direct contact with equipment such as the heat exchanger chamber 7 and the fan motor 114, which are made of acid-resistant materials, will hardly cause corrosion damage to these equipment.

In addition, since the condensed water W discharged to the outside is neutralized by a neutralizing agent, even if it comes into contact with other equipment during discharge, it will not corrode these equipment. do not have. Furthermore, since this condensed water W does not flow into the exhaust silencer 3 through which high-temperature exhaust gas G flows, unlike the conventional structure shown in FIG. 3, it is heated by the exhaust gas G and its acid concentration is condensed. There is no fear that it will happen. That is, the condensed water W is always discharged to the outside in a neutralized state.

Furthermore, the condensed water W condensed in the processing chamber 44 is directly transferred to the third drain pipe 26 from the processing chamber 44.
As in the conventional structure shown in FIG. 3, the condensed water W flows downward through the exhaust muffler 3 and the exhaust gas flows upward through the exhaust muffler 3. and the lower ends 32a, 33a of the communicating pipes 32, 33 or the throttle passages 35A, 35
This eliminates the possibility of collision at B and 35C and generation of unpleasant low frequency sounds.

As mentioned above, this exhaust gas treatment device 40 condenses the moisture in the exhaust gas G to form condensed water W, which is further neutralized by the neutralizing agent, so that the engine For engine-driven air conditioners equipped with gas engines that use natural gas, which has a particularly high sulfur content (including odorants) as fuel, and are surrounded by devices and equipment made of acid-resistant materials. Particularly remarkable results are obtained when applied.

(Effects of the Invention) The exhaust gas treatment device of the present invention has a neutralizing agent layer and a thermal conductor layer arranged in a multi-layered manner in the flow direction of exhaust gas in the treatment chamber, so that strong acids contained in the exhaust gas can be removed. This system condenses the water vapor in the heat conductor layer, neutralizes it in the neutralization layer, and discharges it to the outside, so that the exhaust gas discharged from the engine is directly released to the outside without being neutralized. There is no possibility that peripheral equipment will be corroded and damaged by strongly acidic moisture in the exhaust gas, unlike in the case of exhaust gas, and the durability of the entire device equipped with the engine is improved.

Furthermore, the condensed water contained in the exhaust gas is discharged directly from the processing chamber to the outside without being returned to the exhaust system such as an exhaust silencer.
Unlike the conventional example shown in Fig. 3, low-frequency noise is hardly generated due to the collision between the condensed water flowing into the exhaust muffler and the exhaust gas flow, and the exhaust noise of the engine is reduced accordingly. Another effect is that quiet operation is possible.

[Brief explanation of drawings]

FIG. 1 is an overall system diagram of an engine-driven air conditioner equipped with an exhaust gas treatment device according to an embodiment of the present invention, FIG. 2 is an enlarged vertical sectional view of a portion of FIG. 1, and FIG.
The figure is an overall system diagram of an engine-driven air conditioner with a conventional structure. 43...Exhaust outlet, 44...Processing chamber, 45...
Exhaust gas inlet, 46... Drain port, 51... Neutralizing agent layer, 52, 53... Heat conductor layer, G... Exhaust gas, W... Condensed water.

Claims (1)

[Claims] 1 Exhaust inlet 45, 45... and exhaust outlet 43, 4
3, a neutralizing agent layer 51 made of a neutralizing agent that acts to neutralize the exhaust gas G by contact with the exhaust gas G, and a thermal conductor layer 51 made of a suitable thermal conductor. 52 and 53 are arranged in a multilayered manner in the flow direction of the exhaust gas G, and a drain port 46 is formed at the bottom 44a of the processing chamber 44 for discharging condensed water W condensed in the processing chamber 44. An exhaust gas treatment device characterized by: