JP4356939B2 - Leaky ammonia removal method and apparatus - Google Patents

Description

  In the heat pump using ammonia gas as a refrigerant, such as refrigeration equipment or air-conditioning equipment, the present invention prevents the diffusion of ammonia gas to the outside when ammonia gas leaks without requiring large equipment or initial cost. The present invention relates to a detoxification method and a detoxification device that can be used.

While countermeasures against ozone layer destruction and prevention of global warming have been strongly demanded, in the air conditioning and refrigeration fields, not only defluorocarbons from the viewpoint of ozone layer destruction but also recovery of alternative refrigerant HFC from the viewpoint of global warming There is an urgent need to improve the energy effect.
In order to satisfy the above requirements, use of ammonia, hydrocarbons, air, carbon dioxide, etc., which are natural refrigerants, is conceivable, and ammonia refrigerants are often used in large-scale cooling / refrigeration facilities. Small-scale cooling and refrigeration facilities such as refrigerated warehouses, cargo handling rooms, and processing rooms associated with facilities are also tending to increase the introduction of ammonia as a natural refrigerant.

  The ammonia refrigerant used in the cooling and refrigeration equipment has zero ozone depletion coefficient, zero global warming coefficient, low price, high COP, high heat transfer coefficient, high critical temperature and pressure, easy detection at leakage, expansion valve For the advantages such as no clogging, great freezing effect, toxicity, high compressor discharge temperature, soluble in water and corrosive, copper-based materials cannot be used, not dissolved in oil, There are disadvantages such as.

  By the way, in this kind of refrigeration / air-conditioning equipment, if the refrigerant pipe cracks due to a sudden disaster or accident, for example, ammonia may leak, so the leaked ammonia gas was detoxified. After that, an abatement device that can be released into the atmosphere will be provided, and it is legally required as an abatement provision.

Conventionally, a refrigerator unit using an ammonia refrigerant is installed in a dedicated machine room or in a casing. There are a watering method and a scrubber method in the abatement device.
Patent Document 1 (Japanese Patent Laid-Open No. 6-229644) discloses a water spray type ammonia abatement apparatus. FIG. 3 is a vertical sectional elevation view of this device.
In FIG. 3, this ammonia absorption chiller is provided with a cold water branch pipe 014 in the vicinity of the outlet of the cold water pump 09 of the cold water supply pipe 011, and the branch pipe 014 is connected to the upper space of the chiller main body 01 via the control valve 013. It connects with the watering nozzle 015 provided in. In this ammonia absorption chiller, the aqueous ammonia solution in the ammonia vapor generator 02 is heated by the burner 06 and is converted into high-pressure ammonia vapor and led to the condenser 03. The ammonia cooled and reliquefied by the air cooling fan 07 is decompressed by the orifice type expansion valve 016 and vaporized by the evaporator 04.

  Further, ammonia is dissolved in water by the absorber 05 to become an aqueous ammonia solution, and returned to the generator 02 by the aqueous solution pump 08. When ammonia gas leaks from a part of the circuit through which ammonia circulates, the control valve 013 is immediately opened. The cold water pressurized and supplied by the cold water pump 09 is sprinkled through the cold water branch pipe 014 from the water nozzle 015 into the space where the ammonia gas exists, and absorbs the leaked ammonia gas.

  Patent Document 2 (Japanese Patent Laid-Open No. 2001-347127) discloses a scrubber-type ammonia abatement system. This abatement system, when applying ammonia as a refrigerant in a refrigeration / air conditioning facility, introduces ammonia leaked from the refrigeration unit of this facility to a closed space such as a scrubber before releasing it into the atmosphere, where carbon dioxide and water To produce a salt such as ammonium carbonate or ammonium hydrogen carbonate, which is detoxified.

JP-A-6-229644 JP 2001-347127 A

However, in the case of the watering method, since a method of directly spraying water to the refrigerator unit as in Patent Document 1 has been conventionally employed, the device is immersed in water, and thus it is necessary to make the electrical equipment waterproof.
In addition, rust is generated on the surface of the apparatus, causing failure, and when water is sprinkled on the refrigerant enclosure pipe and piping, there is a problem that the heat is evaporated and the refrigerant evaporates to promote the leakage of ammonia. A huge amount of water is required.
On the other hand, in the case of the scrubber method disclosed in Patent Document 2, a large-scale facility for scrubber processing is required separately from the refrigerator unit, and there is a problem of increasing the facility cost.

  FIG. 4 is a non-known water spray type ammonia abatement apparatus proposed by the present inventors before reaching the present invention, and this apparatus will be described below as a comparative example. 4, reference numeral 021 denotes a dedicated machine room or a dedicated casing in which a heat pump unit including a compressor 022, an evaporator 023, a condenser 024, an air heat exchanger coil 033, and the like is installed. Reference numeral 025 denotes another casing provided at the upper portion of the casing 021. Inside the casing 025, a ventilation duct 027 for ventilating the atmosphere in the casing 021 and an air heat exchanger coil 033 are provided on the floor 026. Yes. A fan 028 that sucks the atmosphere in the casing 021 is provided inside the ventilation duct 027, and an electric shutter 029 that closes when ammonia gas leaks inside the casing 021 is provided at the outlet 027 a of the ventilation duct 027.

  030 is a ventilation fan that ventilates the air heat exchanger coil 033 through an opening provided in the fan frame 031. Reference numeral 032 is a watering nozzle distributed in the vicinity of the ceiling inside the casings 021 and 025, and water for watering is supplied to the watering nozzle 032 from a water tank 034 provided under the floor of the casing 021 through a pipe (not shown). The Reference numeral 035 denotes an air vent / electric shutter. Normally, air in the casing 021 is sucked by the fans 028 and 030 to ventilate the casing 021, and outside air is introduced from the air vent / electric shutter 035.

  In such an apparatus, when the refrigerator unit in the casing 021 is operating normally, the fans 028 and 030 are operated and air is ventilated through the electric shutter 029, but leakage of ammonia from the unit is detected. At that time, the ventilation fan 030 and the fan 028 immediately stop operating, and the electric shutter 029 and the ventilation opening / electric shutter 035 close their openings so that the casing 021 and the ventilation duct 027 are sealed from the outside, and at the same time, the casings 021 and 025 are closed. Water is sprinkled from the watering nozzles 032 arranged in a distributed manner.

As a result, the sprinkled water absorbs the leaked ammonia gas, and the absorbed liquid that has absorbed the ammonia gas is returned to the water tank 034 through a pipe (not shown), thus preventing the release of ammonia gas from the casings 021 and 025. , Leaked ammonia can be removed.
Since FIG. 4 is an example of a heat pump, the ammonia gas leakage in the casing 021 and the ammonia gas leakage in the casing 025 are respectively sprinkled up and down, but if the heat pump is not used, there may be no upper casing 025.

  However, in the apparatus of this comparative example, it is possible to prevent the leaked ammonia gas from diffusing out of the casings 021 and 025, but still water is directly sprayed to the refrigerator unit, and the above-mentioned problem is solved. In addition, since water is sprayed to both the casings 025 and 021, a huge amount of water is required.

  In view of the problems of the prior art, the present invention eliminates the above-mentioned problems by realizing ammonia detoxification that does not spray water directly on the refrigerator unit, and does not require large-scale equipment and initial cost. To propose an ammonia detoxification method capable of reducing ammonia and detoxifying ammonia while reliably preventing leakage of ammonia from the compartment where the refrigerator unit is installed, and an apparatus for realizing the method With the goal.

The ammonia detoxification method of the present invention achieves the above-mentioned object,
In the ammonia abatement method in which ammonia gas leaked from a refrigerator or heat pump using ammonia as a refrigerant is absorbed by the sprinkled water, the interior of the compartment provided adjacent to the compartment where the refrigerator or heat pump is installed Sprinkle water into a sealable abatement zone that communicates with the water to absorb ammonia gas.
A negative pressure corresponding to the disappearance of the ammonia gas volume is formed by absorption of ammonia gas in the detoxification section, and the ammonia gas is sucked out from the section where the refrigerator or heat pump is installed, and the ammonia gas is discharged from the section to the outside. It is characterized by preventing leakage.

In the method of the present invention, when ammonia gas leaks, the inside of the abatement zone is sprinkled in the abatement zone adjacent to and connected to the same zone without watering in the zone where the refrigerator or heat pump is installed. The ammonia gas is absorbed in water, the ammonia gas is drawn in, and water is sprinkled in the abatement zone to absorb the ammonia gas in the sprinkled water.
When ammonia gas is absorbed into water, it loses its volume and creates a negative pressure corresponding to that volume. As a result, the inside of the abatement zone becomes a negative pressure, and air containing ammonia gas further flows into the abatement zone from the zone where the refrigerator or heat pump is installed, thereby further promoting the elimination of ammonia.

Therefore, the higher the concentration of the leaked ammonia gas, the more the ammonia gas is removed by flowing into the abatement zone. The inside of the abatement zone can be sealed, and a negative pressure is maintained by the loss of volume of ammonia gas (the higher the concentration, the more negative the pressure). Therefore, ammonia is placed outside the chiller or heat pump installation zone and the abatement zone. There is no leakage.
Note that the abatement section has a structure that can be sealed to the outside as soon as ammonia leaks in a section where a refrigerator or the like is installed. For example, an ammonia detection sensor and an electric shutter that closes the opening immediately after a signal from the detection sensor is input in the abatement zone may be provided.

In the method of the present invention, a circulation system in which water that has absorbed ammonia gas is returned to a water tank that is a supply source of water spray may be employed, or water that has absorbed ammonia gas may be discharged to another treatment facility.
In the method of the present invention, preferably, the concentration of ammonia gas evaporated from the ammonia gas absorption water is detected, and the amount of water spray is increased or decreased based on the detected value.

The apparatus of the present invention includes a refrigerator or a heat pump that is installed in a specific section and uses ammonia as a refrigerant, and water that absorbs ammonia gas leaked from the refrigerator or heat pump as an apparatus for carrying out the method of the present invention. In a leaky ammonia abatement apparatus comprising a nozzle for watering, a water tank for supplying water to the nozzle and a pump,
An abatement zone provided adjacent to the specific zone and sealable when ammonia gas leaks;
A communication port for sucking ammonia gas leaked from the compartment where the refrigerator or heat pump is installed in the abatement zone;
A watering nozzle disposed inside the abatement section is provided.

  The method of the present invention can be carried out using the device of the present invention. That is, when leakage of ammonia gas is detected in a specific section where a refrigerator or a heat pump is installed, the specific section and the abatement section are immediately sealed, and water spraying is started in the abatement section. The ammonia gas is absorbed into the water by the water spray, and the detoxification section becomes negative pressure by the volume of the ammonia gas, and the ammonia gas is further sucked to promote the detoxification.

  The apparatus of the present invention preferably includes a sensor that detects the concentration of ammonia gas that evaporates from the ammonia gas absorption water, and a controller that increases or decreases the amount of water sprayed from the watering nozzle based on the detected value. The amount of water spray is increased or decreased based on the detected ammonia value. As a result, the amount of detoxifying water that has absorbed ammonia gas can be reduced, and the amount of sprinkling can be saved thereby, so that the time for detoxification can be extended.

  According to the method of the present invention, the ammonia gas is absorbed in water by spraying water in a sealable abatement zone provided adjacent to a compartment where a refrigerator or a heat pump is installed and communicating with the inside of the compartment. By forming a negative pressure corresponding to the disappearance of the ammonia gas volume by absorption of ammonia gas in the harmed compartment, the ammonia is sucked from the compartment where the refrigerator or heat pump is installed to further promote the detoxification. Can be reliably prevented from leaking from the installation section and the abatement section of the refrigerator or the like.

Further, since water is not sprinkled in the compartment where the refrigerator or heat pump is installed, each device constituting the refrigerator or heat pump is not submerged, and there is no need to worry about the occurrence of rust and electric leakage. Further, it is possible to prevent the refrigerant from being vaporized by the heat of the water spray and causing further leakage of ammonia.
In the method of the present invention, preferably, the amount of detoxified water that has absorbed ammonia gas by detecting the concentration of ammonia gas that evaporates from the ammonia gas absorption water and increasing or decreasing the amount of water spray based on the detected value. Can be reduced, and the amount of watering can be saved, so that the time for abatement can be extended.

  Further, according to the apparatus of the present invention, an abatement zone that is provided adjacent to a specific zone where a refrigerator or a heat pump is installed and can be sealed when ammonia gas leaks, and the refrigerator or heat pump is installed in the abatement zone. The method according to the present invention is carried out without requiring large-scale equipment and initial cost, by providing a communication port for sucking ammonia gas leaked from the section and a watering nozzle arranged inside the abatement section. Therefore, the effect by implementing the above-mentioned method of this invention can be show | played.

Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.
FIG. 1 is a vertical sectional elevational view showing a first embodiment of the ammonia abatement apparatus of the present invention, and FIG. 2 is a block diagram showing a control system of the first embodiment.

In FIG. 1, 1 is a casing in which a heat pump unit composed of a compressor 2, an evaporator 3, a condenser 4, an air heat exchanger coil 13 and the like is installed, and 5 is a spray nozzle 12 and 15 It is the casing which comprises the installed abatement zone. Reference numeral 7 denotes a ventilation duct that sucks the atmosphere in the casing 1 from a communication port (not shown) provided on the floor surface 6 of the casing 5. A watering nozzle 15 is installed. A U-shaped tube 18 is provided at the lower part of the water storage unit 17, and is configured to seal the inside of the ventilation duct 7 when water sprinkled in the water storage unit 17 accumulates.
Inside the ventilation duct 7, a fan 8 for sucking the atmosphere in the casing 1 and an electric shutter 9 at the outlet 7a of the ventilation duct 7 are provided to form an ammonia abatement zone.

Reference numeral 19 denotes an ammonia concentration detector that detects leakage of ammonia inside the casing 5, and as shown in FIG. 2, when ammonia is detected in the casing 5, the control device 20 automatically detects the electric shutter 9. The drive motor 21 is driven to close the electric shutter 9 and the operation of the ventilation fan 10 and the fan 8 is stopped.
Reference numeral 22 denotes a drain pipe that returns water that has been sprinkled in the casing 5 and absorbed ammonia to the water tank 14, and the opening thereof is open to the floor surface 6 of the casing 5. A water supply pump 23 is provided in a supply pipe 24 that supplies water stored in the water tank 14 to the watering nozzles 12 and 15 when ammonia leaks.

As shown in FIG. 2, the control device 20 is configured to control the driving of the pump 23 based on the detection value of the detector 19 and adjust the amount of water spray supplied to the water spray nozzle 15.
The watering nozzle 12 is necessary when applied to a heat pump as in this embodiment, and performs watering against leakage of ammonia gas from the air heat exchanger coil 13 or the like. The watering nozzle 12 is not particularly required when it is not a heat pump.

In the apparatus according to the first embodiment, when the refrigerant unit installed in the casing 1 is operating normally, the fan 8 and the ventilation fan 10 are operated to open the casing 1 from the opening provided in the fan frame 11. The air inside flows through the casing 5 to the outside of the casing. On the other hand, the outside air flows into the casing 1 from the air vent / electric shutter 16 to circulate the air.
In normal operation, of course, there is no water spray from the water spray nozzle 12 or 15.

  When the ammonia concentration detector 19 detects the leakage of ammonia, the control device 20 immediately issues a command to the drive device 21 of the electric shutter 9 and the vent / electric shutter 16 to open the electric shutter 9 and the vent / electric shutter 16. Is closed, a command is issued to the drive device 26 of the fan 8 and the ventilation fan 10, and the fan 8 and the ventilation fan 10 are stopped. As a result, the casing 1 and the inside of the ventilation duct 7 are sealed, and an operation command is issued from the control device 20 to the drive motor 25 of the pump 23, and watering is started from the watering nozzle 15.

  Inside the ventilation duct 7, the ammonia gas leaked by the start of watering is absorbed by the watering, and when the ammonia gas is absorbed by the watering, its volume is lost, and thereby the inside of the ventilation duct 7 becomes negative pressure and the casing 1 Air containing ammonia further flows from the inside through the ventilation duct 7. This further promotes ammonia detoxification. The watering nozzle 12 performs watering when ammonia gas leaks from the air heat exchanger coil 13.

The higher the leaked ammonia gas amount in the casing 1, the more ammonia gas flows into the ventilation duct 7 and the amount of ammonia gas absorbed by the water spray increases, so the negative pressure in the casing 1 is maintained (high As the concentration becomes negative, the pressure inside the casing 1 becomes negative, so that ammonia does not leak out of the casing 1.
Further, in the first embodiment, water w that has been sprinkled into the water storage part 17 in the ventilation duct 7 and absorbed ammonia is collected, and the inside of the ventilation duct 7 is sealed. As a result, the inside of the casing 1 is completely sealed, and ammonia gas does not leak to the outside.

Further, the ammonia concentration detector 19 detects the concentration of ammonia gas evaporated from the ammonia-absorbed water inside the casing 5, and the control device 20 controls the rotational speed of the drive motor 25 of the pump 23 according to the detected value. The discharge amount of the pump 23 is controlled, and the amount of water sprayed from the water spray nozzle 15 is increased or decreased. That is, when the ammonia concentration is high, the watering amount is increased, and when the ammonia concentration is low, the watering amount is decreased.
As a result, the amount of ammonia-absorbed water can be reduced, and the time for performing the detoxification operation can be extended.

Thus, according to the first embodiment, since water is not sprinkled on the casing 1 in which the refrigerator unit is installed, each device constituting the refrigerator unit is not submerged, and there is a concern about the occurrence of rust, leakage, etc. In addition, it is possible to prevent the refrigerant from being vaporized by the heat of the water spray and further causing leakage of ammonia.
In addition to providing the ventilation duct 7 as an abatement casing separately from the casing 1 in which the refrigerator unit is installed, it is possible to achieve the abatement effect without requiring large facilities and expensive initial costs, Leakage of ammonia out of the casing can be reliably prevented.

  If the heat pump unit is not as in the first embodiment, the casing 5 is not necessary, and it is only necessary to provide a receptacle for the water distribution pipe 22 from the U-shaped pipe 18. In that case, the ammonia concentration detector 19 detects the detoxified water transpiration concentration in the vicinity of the receptacle of the water distribution pipe 22.

  According to the present invention, by realizing ammonia detoxification that does not sprinkle water directly on the refrigerator unit, each device constituting the refrigerator unit is not submerged, and there is a concern about the occurrence of rust, leakage, etc. It is possible to prevent the refrigerant from evaporating due to the heat of water spray and prevent further leakage of ammonia, without requiring large equipment and initial cost, and to reduce the amount of water spray, An ammonia detoxification method and detoxification apparatus capable of detoxifying ammonia while reliably preventing leakage of ammonia from the compartment where the heat pump is installed can be realized.

It is a vertical elevation view of the first embodiment of the device of the present invention. It is a block diagram of the control apparatus of the first embodiment. It is a vertical section which shows the conventional ammonia abatement apparatus. It is a vertical sectional elevation view of the ammonia abatement apparatus proposed by the present inventors before reaching the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat pump installation casing 2 Compressor 3 Evaporator 4 Condenser 5 Casing 6 Floor surface 7 Ventilation duct (abatement casing)
8 fans
9 Electric Shutter 10 Ventilation Fan 11 Fan Frame 12, 15 Watering Nozzle 13 Air Heat Exchanger Coil 14 Water Tank
16 Ventilation / electric shutter 17 Water storage 18 U-shaped pipe 19 Ammonia concentration detector 22 Drain pipe 23 Supply pump 24 Water supply pipe w Water storage

Claims (4)

In the ammonia abatement method in which ammonia gas leaked from a refrigerator or heat pump using ammonia as a refrigerant is absorbed by the sprinkled water, the interior of the compartment provided adjacent to the compartment where the refrigerator or heat pump is installed Sprinkle water into a sealable abatement zone that communicates with the water to absorb ammonia gas.
A negative pressure corresponding to the disappearance of the ammonia gas volume is formed by absorption of ammonia gas in the detoxification section, and the ammonia gas is sucked out from the section where the refrigerator or heat pump is installed, and the ammonia gas is discharged from the section to the outside. Leakage ammonia abatement method characterized by preventing leakage.   2. The leaked ammonia abatement method according to claim 1, wherein the concentration of ammonia gas evaporated from the ammonia gas absorption water is detected, and the amount of water spray is increased or decreased based on the detected value. A refrigerator or heat pump installed in a specific section and using ammonia as a refrigerant, a nozzle for spraying water that absorbs ammonia gas leaked from the refrigerator or heat pump, and a water tank and a pump for supplying water to the nozzle In the leakage ammonia abatement device provided,
An abatement zone provided adjacent to the specific zone and sealable when ammonia gas leaks;
A communication port for sucking ammonia gas leaked from the compartment where the refrigerator or heat pump is installed in the abatement zone;
A leaking ammonia abatement apparatus comprising a watering nozzle disposed inside the abatement section.   4. The sensor according to claim 3, further comprising: a sensor that detects a concentration of ammonia gas that evaporates from the ammonia gas absorption water; and a controller that increases or decreases the amount of water sprayed from the water spray nozzle based on the detected value. Leaky ammonia abatement device.

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