JP3066828B1 - Ammonia refrigeration system leakage ammonia elimination device - Google Patents

Abstract

A leak ammonia abatement system for an ammonia refrigeration system that does not damage the refrigeration system and does not corrode pipes and valves when an ammonia leak accident occurs. SOLUTION: In a first plate type heat exchanger 2, heat of seawater and heat of fresh water are exchanged, and in a second plate type heat exchanger 3, the heat of fresh water cooled by seawater and the high pressure and high temperature refrigerant are exchanged. In the third plate heat exchanger 4, the heat exchanges with the heat of the liquefied refrigerant and the heat of the fresh water circulating between the air-conditioning heat exchanger 5 in the third plate heat exchanger 4 after the expansion valve 12. Cold air is blown to 64. When ammonia leaks, compressed air is blown by opening and closing the plurality of spray ports 19 provided in the air pipe 17 disposed above the refrigerator compartment 1 and the electromagnetic valve 18,
Or shut off the ventilation. The air and the air mixture are exhausted to the outside of the refrigerator 1 from the discharge port 20 and the duct 21 provided at the upper part of the refrigerator room 1, and the air is taken in from the suction port 23 provided below the refrigerator room 1. did.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for removing leaked ammonia from an ammonia refrigeration system for air-conditioning (cooling) a living room of a ship.

[0002]

2. Description of the Related Art In a living room in a ship, an air conditioning system is provided to keep the living room at a comfortable temperature, and an ammonia refrigeration system using ammonia as a cooling medium for cooling is conventionally used. This type of ammonia refrigerating apparatus compresses, expands, and circulates ammonia as a refrigerant, and cools the ammonia using heat of vaporization when the ammonia expands. Ammonia has a specific gravity of 0.6167＠15/4° C., a boiling point of −33.35 ° C., a flash point of 0 ° C. or less, and a freezing point of −7.
7.7 ° C, vapor pressure 3psig ＠ -30 ° C, 50psi
ng ＠ 0 ° C., 290 psing ＠ + 50 ° C., steam specific gravity is about 0.6, viscosity is 0.207 cp ＠ 20 ° C., ignition point is 6
It is a colorless liquefied gas with an explosion limit of 51 ° C and an explosion limit of 16% to 25%.

FIG. 2 is a schematic configuration diagram of a conventional ammonia refrigerating apparatus using a refrigerant having such properties.
50 is a refrigerator room, 51 is a seawater pipe through which seawater flows, 52 is a seawater pump that pumps seawater into the seawater pipe 51, and 53 is a tube-type first heat exchange in which a spiral tube is provided. , A refrigerant pipe for circulating ammonia as a refrigerant, 55 a compressor for compressing a refrigerant circulating in the refrigerant pipe, 56
Is an expansion valve for reducing the pressure of the refrigerant compressed by the compressor 55, 57 is a second heat exchanger similar to the first heat exchanger, 58 is a fresh water pipe through which fresh water circulates, 59 is
A fresh water pump for circulating fresh water in the fresh water pipe 58, 60 is an air conditioner heat exchanger, and 61 is a blower that blows cool air having undergone heat exchange by the air conditioner heat exchanger 60. Reference numeral 62 denotes an air conditioner room in which the air-conditioning heat exchanger 60 and the blower 61 are disposed, 63 denotes a ventilation path through which the cool air flows, 64 denotes a steering room for performing air conditioning (cooling), a passenger compartment, and the like. It is a plurality of living rooms including.

In the air conditioning (cooling) of the living room 64 or the like by the ammonia refrigeration apparatus, seawater pumped by the seawater pump 52 flows through the seawater pipe 51, and the ammonia circulated through the refrigerant pipe 54 by the heat of the seawater. The ammonia cooled and cooled by the first heat exchanger 53 takes away the heat of the fresh water circulating through the fresh water pipe 58 and vaporizes by the second heat exchanger 57. At this time, the fresh water is cooled by the heat of vaporization. The cooled fresh water exchanges heat with the air by the air-conditioning heat exchanger 60, and the cooled air is blown by the blower 61, and cool air is blown to each living room 64 through the ventilation passage 63.

In the above-described conventional ammonia refrigerating apparatus, for example, cracks or leaks from joints occur in pipes or the like in which ammonia as a refrigerant circulates, and the refrigerator compartment 5
Assuming an accident where ammonia leaks to zero,
Leaked ammonia reacts with acids, including oxidants, causing serious burns when liquids come into contact with the human body, and high concentrations of ammonia vapors cause severe irritation when in contact with skin and, when inhaled by the human body, can cause respiratory tract damage. Attention must be paid to the use of ammonia, as it can cause severe irritations that can cause dyspnea, adverse effects on the heart, and permanent damage to the lungs. For this reason, the refrigerator room 50 must be provided with a leaked ammonia exclusion facility for immediately removing leaked ammonia based on NKRule (Nippon Kaiji Kyokai (Classification Rules)).

For this reason, as shown in FIG. 2, when this kind of ammonia refrigeration apparatus is used, the water sprinkler 6
5. A water pipe 66, a valve 67 for opening and closing the water pipe 66 to send and stop water, a plurality of water pipes provided on the water pipe 66 for dispersing water for dissolving leaked ammonia to form ammonia water. A sprinkler 68 provided below the refrigerator compartment 50, a drain pipe 69 through which the ammonia water flows, and a drain pump 70 for draining the ammonia water out of the drain pipe 69 from the drain pipe 69. It is supposed to be provided. Further, a tray 50a for storing the ammonia water is provided on a floor portion of the refrigerator room 50, and the ammonia water stored in the tray 50a is sucked from one end of the drain pipe 69 and drained. It has become.

That is, since ammonia dissolves in water and is stabilized, the valve 67 of the water pipe 66 is opened to send water to the water pipe 66, and water is sprinkled from the sprinkler 68 into the refrigerator room 50. Ammonia is dissolved in water to form ammonia water. The ammonia water collects in the tray 50a of the refrigerator compartment 50, is sucked by the drain pump 70, drained out of the drain pipe 69 out of the boat, and is removed.

[0008]

However, the ammonia refrigeration apparatus as described above uses a tube type heat exchanger in which tubes are formed in a spiral shape for the first heat exchanger and the second heat exchanger. Therefore, a large amount (about 70 kg) of ammonia as a refrigerant was required. A large amount of ammonia
In the unlikely event that a leak occurs due to an accident or the like, it is assumed that the crew and passengers will be greatly damaged as described above. In addition, the above-described ammonia refrigeration system is designed to sprinkle water and dilute it as ammonia water when a large amount of ammonia is leaked due to an accident or the like. Equipment is required. In such a case, copper or its alloy, aluminum or its alloy, galvanized (electroplated) surface, phenolic resin or polyester resin will corrode even though it is diluted ammonia water,
There is a problem that the drain pipe, the valve, the drain pump, and the like are corroded. Furthermore, if the above-mentioned leaked ammonia exclusion equipment is specified, water or seawater is required to dilute the ammonia, and when diluting with water, a large amount of water should be prepared in case of an accident that should not occur. Must be loaded and stored in advance, and when diluted with seawater, facilities such as pumping seawater are required, and pipes, water pipes, sprinklers, etc. through which seawater flows are included in seawater. In order to prevent corrosion and clogging due to salt and impurities, it is necessary to perform maintenance work on these facilities at all times. In addition, a problem can be assumed in which water is sprayed on the main body device including the electric device due to water spray, and the device is damaged.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and an ammonia refrigeration system using a small amount of ammonia to be used as a refrigerant is arranged in a living room while performing the same cooling as before. Even in the event of an accident, a leak ammonia exclusion facility was installed to dilute the leaked ammonia with compressed air and exhaust it outside the ship, without damaging the main unit, and drain pumps and drains for draining the ammonia water. An object of the present invention is to provide a leakage ammonia elimination device of an ammonia refrigeration device that does not corrode valves and the like provided on pipes and drainage pipes.

[0010]

According to a first aspect of the present invention, there is provided an ammonia refrigeration apparatus for exchanging heat between seawater heat flowing through a seawater pipe and freshwater heat circulating through a circulation pipe. A first plate heat exchanger, the heat of low-temperature fresh water circulating through the circulation pipe heat exchanged by the first plate heat exchanger, and a small amount of refrigerant circulating through the refrigerant pipe to become high temperature by the compressor. A second plate heat exchanger that exchanges heat with the heat of the refrigerant,
A small amount of refrigerant is heat-exchanged by the second plate heat exchanger, and a small amount of refrigerant circulates through the refrigerant pipe and circulates between the heat of the refrigerant cooled by the expansion valve and the air-conditioning heat exchanger that cools the air. In a refrigerator room in which a third plate heat exchanger for exchanging heat with fresh water is arranged, a portion above the refrigerator room
With multiple spray outlets to blow out compressed air
An air pipe, provided on the air pipe,
Ventilation of compressed air or compressed air to the air pipe in closed state
A solenoid valve for closing air flow, and a predetermined upper portion of the refrigerator compartment
Air and air mixing in the refrigerator room
Discharge port and duct for discharging gas outside the specified refrigerator room
Provided below the refrigerator compartment and evacuated from outside the refrigerator compartment.
And a suction port for taking in air , wherein the leaked ammonia is removed by ventilation. Claim 2 of the present application
The invention according to claim 1, wherein in the leakage ammonia elimination apparatus for the ammonia refrigeration apparatus according to claim 1, the refrigerator compartment
Ventilation fan that ventilates the air or air mixture
It is characterized by being provided in one of the duct and the intake port .

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing the structure of an ammonia refrigerating apparatus according to the present invention. FIG. 1 is a schematic configuration diagram of a leakage ammonia elimination apparatus of an ammonia refrigeration apparatus according to the present invention. In the drawing, reference numeral 1 denotes a refrigerator room provided on a ship, where an ammonia refrigeration apparatus is disposed; A first plate heat exchanger for heat exchange between seawater and fresh water provided for the purpose of avoiding mixing of seawater, 3 is a second plate heat exchanger composed of a flat plate using a small amount of ammonia, and 4 is A three-plate heat exchanger, 5 is an air-conditioning heat exchanger that is provided in the air-conditioning room 62 and sends cold air to each living room, 6 is a seawater pipe, 7 is a seawater pump, and 8 is a circulation pipe, as in the prior art. , 9
A circulation pump for circulating fresh water through the circulation pipe 8;
Is a refrigerant pipe through which ammonia as a refrigerant circulates;
, A compressor, 12 is an expansion valve, 13 is a chilled water pipe, 14 is a chilled water pump for circulating fresh water through the chilled water pipe 13, 15 is provided in the air conditioning heat exchanger 5,
It is a blower that blows cool air. The cool air blown from the blower 15 is supplied to a plurality of living rooms 64 including a steering room, a crew room, and the like for performing air conditioning (cooling) from the air conditioner room 62 through a ventilation path 63 through which the cool air flows, as in the related art. It is configured to be blown.

According to the NKRule (Nippon Kaiji Kyokai (Classification Regulations)), the refrigerator compartment 1 has a dedicated compartment separated by a confidential partition wall and deck so that leaked ammonia does not leak to other compartments for safety. And
The installation section is a dedicated section on the ship that is not adjacent to the living room, the wheelhouse, and the control room, and is separated by a confidential bulkhead and deck. At least two or more doors are installed as far as possible, It is stated that at least one of the doors must be provided with an opening on the directly exposed deck. In this embodiment, the number of doors is one because the amount of ammonia used is small. Be placed. The first plate heat exchanger 2 cools fresh water circulating through the circulation pipe 8 by heat of seawater flowing through the seawater pipe 6. This is provided in order to prevent seawater containing many impurities and highly corrosive from contaminating the heat exchanger through which ammonia circulates or directly corroding the heat exchanger when performing heat exchange.

The second plate type heat exchanger 3 uses the heat of the fresh water circulating through the circulation pipe 8 to heat the refrigerant pipe 10
The cooling medium circulating is cooled. The third plate heat exchanger 4 cools the fresh water circulating through the cold water pipe 13 by the heat of the refrigerant circulating through the refrigerant pipe 10. This is because when the ammonia leaks from the refrigerant pipe 10, the heat of the fresh water cooled by the ammonia is converted into cold air by the air-conditioning heat exchanger 5 so that the cold air mixed with the ammonia is not blown to the living room 64. The air is sent to the living room 64 at 15.

The refrigerant pipe 10 is a pipe through which ammonia as a refrigerant circulates between the second plate type heat exchanger 3 and the third plate type heat exchanger 4. In this embodiment, the refrigerant pipe The amount of ammonia circulating through 10 is
It is about 7kg. This refrigerant pipe 10 has a lower limit of 70 kg / cm ² on the high pressure side of the refrigerant (ammonia) between the compressor 11 and the expansion valve 12, and has a lower limit of 70 kg / cm ² on the low pressure side of the refrigerant (ammonia) between the expansion valve 12 and the compressor 11. Those that can withstand 15 kg / cm ² are used.

The compressor 11 is provided on the refrigerant pipe 10 through which the refrigerant circulates from the third plate heat exchanger 4 to the second plate heat exchanger 3. Is compressed to a high temperature and a high pressure. The expansion valve 12 is provided on the refrigerant pipe 10 through which the refrigerant circulates from the second plate heat exchanger 3 to the third plate heat exchanger 4. The liquid ammonia (refrigerant) is squeezed and expanded to create a low-temperature, low-pressure gas-liquid mixed state. This refrigerant is vaporized in the third plate heat exchanger 4, and heat exchange (cools the fresh water) with the fresh water by the heat of vaporization.

Next, the cooling of the living room by the ammonia refrigeration system having the above-described configuration will be described. To cool the living room 64, the ammonia refrigeration system is driven and the compressor 1
1 and the expansion valve 12 are driven to circulate the refrigerant (ammonia) in the refrigerant pipe 10. This refrigerant (ammonia) becomes high pressure and high temperature by the compressor 11, and exchanges heat with the heat of fresh water circulating through the circulation pipe 8 in the second plate heat exchanger 3 to be cooled. The fresh water circulating in the circulation pipe 8 is cooled by the heat exchange with the heat of the seawater flowing through the seawater pipe 6 in the first plate heat exchanger 2, returned to the second plate heat exchanger 3, and returned to the refrigerant ( Ammonia).

The refrigerant (ammonia) cooled in the second plate type heat exchanger 3 has a low pressure and low temperature in the expansion valve 12, and exchanges heat with fresh water circulating in the cold water pipe 13 in the third plate type heat exchanger 4. Is performed to cool the fresh water. The air blown to the living room is cooled by the air-conditioning heat exchanger 5 with the cooled fresh water. The cooled air is supplied to the blower 15
Is blown to each living room 64 through the ventilation passage 63. As described above, by using the plate heat exchangers such as the first plate heat exchanger 2, the second plate heat exchanger 3, and the third plate heat exchanger 4, the refrigerant circulating through the refrigerant pipe 10 is used. The amount of used is small, and heat exchange is performed efficiently.

The ammonia refrigerating apparatus according to the present embodiment is a plate-type heat exchanger that requires a small amount of refrigerant, and has the following equipment for excluding leaked ammonia in case ammonia leaks. Is provided. Less than,
The leaked ammonia elimination equipment will be described. In FIG. 1, 1
6 is a spraying device, 17 is an air pipe, 18 is an electromagnetic valve for sending air to the air pipe 17, and 19 is a plurality of spray ports provided in the air pipe 17. Reference numeral 20 denotes a discharge port provided in a ceiling portion as a predetermined upper position of the refrigerator compartment 1, reference numeral 21 denotes a duct provided from the discharge port 20 to an external predetermined exhaust position, and reference numeral 22 denotes a duct 2
The large-capacity ventilation fan 23 provided at 1 is an intake port provided below the refrigerator room 1.

An air pipe 17 is provided so as to communicate from the upper portion of the ammonia refrigeration apparatus to an air tank (not shown) provided outside the refrigerator chamber 1 and containing compressed air (not shown). When the solenoid valve 18 provided on the air pipe 17 is opened, the air pipe 17 is opened from an air tank (not shown).
The air is ventilated. The solenoid valve 18 is linked to an ammonia leak sensor (not shown) provided in the refrigerator compartment 1, so that the ammonia concentration in the refrigerator compartment 1 is 150
The electromagnetic valve 18 is configured to open when the amount becomes ppm or more. A plurality of spray ports 19 are provided in the air pipe 17, and compressed air is supplied from above the ammonia refrigerating apparatus (especially near the center of the refrigerant pipe 10) to dilute the leaked ammonia into ammonia mixed air. 10m
Spray at ³ / h.

The discharge port 20 is provided so as to discharge the diluted ammonia mixed air to the outside. In this embodiment, since the vapor specific gravity of ammonia is 0.6, which is lighter than air, the refrigerator compartment 1 To quickly discharge the diluted ammonia. The duct 21 is provided in communication with the discharge port 20, and discharges the diluted ammonia to the outside. This duct 21
According to KRule (Nippon Kaiji Kyokai (Classification Regulations)), the nearest air intake or opening such as a residential area, a service area, and a control place is at least 10 m horizontally and at least 4 m vertically from the exposed deck. The outlet must be provided at a position, and in the present embodiment, it is arranged based on this.

The ventilation fan 22 is provided in the ventilation path of the duct 21 and always (about 30 times / hour) forcibly discharges the diluted ammonia in the refrigerator room 1 from the duct 21 to the atmosphere. The ventilation fan 22 has an ability to reduce the ammonia concentration of 150 ppm or more leaked into the refrigerator compartment 1 by the ventilation fan 22 to 25 ppm or less within 1 to 7 minutes. The ventilation fan 22 and the duct 21
According to NKRule, since a structure that does not emit sparks must be used, an aluminum or magnesium alloy that may cause sparks should not be used in combination with an iron-based material. A material based on the above is used. The intake port 23 is provided below the refrigerator compartment 1 away from the discharge port 20 and the duct 21, and takes in fresh air into the refrigerator compartment 1.

Next, a description will be given of a situation in which the leaked ammonia is removed by the leaked ammonia removing equipment having the above-described configuration when an accidental ammonia leak accident is assumed in the refrigerator room 1. When the ammonia leaks into the refrigerator compartment 1, an ammonia leak sensor (not shown) senses the ammonia, and the circulation pump 9, the compressor 11,
The expander 12, the chilled water pump 14, etc. are stopped, and the ammonia refrigeration system is stopped. Next, the solenoid valve 18 linked with the ammonia leak sensor (not shown) opens, and compressed air
An air pipe 17 flows through a compressed air tank (not shown) and blows out from the spray port 19 into the refrigerator compartment 1.

When the ammonia leaking into the refrigerator compartment 1 is liquid ammonia, it is diluted by the atmosphere and is further vaporized quickly by compressed air (boiling point: −33.35 ° C.).
The vaporized ammonia is diluted with compressed air, and when the leaked ammonia is ammonia vapor, the ammonia is diluted with compressed air as it is, and the diluted ammonia is discharged from the discharge port 20 and the duct 21 into the atmosphere. Is discharged. At this time, the diluted ammonia in the refrigerator compartment 1 is quickly and forcibly discharged into the atmosphere by the ventilation fan 22 provided in the duct 21 to be eliminated, and the inside of the refrigerator compartment 1 is Fresh air is taken in from the air inlet 23.

In the above embodiment, the spraying device 16 for spraying the air for diluting the ammonia is provided at the upper part of the refrigerator compartment and the air is sprayed downward. It may be provided below the machine room and air may be sprayed upward to dilute ammonia, or air may be sprayed from the side, and if the ammonia can be efficiently diluted and exhausted, the spraying device 16 Is not particularly limited. In the above embodiment, the ventilation fan 22 provided in the duct 21 is operated to constantly exhaust the refrigerator compartment 1, but when ammonia leaks into the refrigerator compartment 1, an ammonia leakage sensor is used. (Not shown), the exhaust capacity of the ventilation fan 22 may be increased to increase the exhaust volume of the refrigerator compartment 1. In the above embodiment, the ventilation fan 22 is provided in the duct 21 and the diluted ammonia is discharged from the refrigerator compartment 1 to the atmosphere. However, the ventilation fan 22 is provided in the intake port 23 for taking in fresh air. Alternatively, fresh air may be rapidly and forcibly taken in by the ventilation fan.

[0025]

As described above, the leaked ammonia removing device of the ammonia refrigeration system of the present application performs heat exchange between seawater and fresh water with the first plate heat exchanger, and the second plate heat exchanger 3 Since the heat exchange between the fresh water and the refrigerant is performed in the third plate type heat exchanger 4, the amount of the highly dangerous ammonia used in the refrigeration system itself can be greatly reduced, and the safer one can be obtained. can do. If the amount of ammonia used in this way is small,
Even if ammonia leaks, the leaked ammonia is diluted with air and the low-concentration ammonia is exhausted, so that it can be quickly removed from the refrigerator compartment to the outside of the ship. Can also ensure high security. According to the leakage ammonia elimination apparatus of the ammonia refrigeration apparatus according to the present invention, water is not sprayed on the refrigeration apparatus at the time of leakage of ammonia as in the related art, so that damage such as malfunction or failure of electric equipment or the like due to water spray may occur. Disappears. Also, at the time of leakage, even if ammonia is exhausted into the atmosphere, since the global warming potential and ozone depletion potential of ammonia are zero, they are small, so they can be flown to the sea as in the past, There is an advantage that the environment is less polluted, and even when the ammonia water is discharged, the water distribution pipes and valves of the ship are not corroded.
Furthermore, the refrigerator compartment is provided with an exhaust outlet, duct, ventilation fan, and an intake port for taking in fresh air, and the refrigerator compartment is constantly ventilated, so even if ammonia leaks, high concentrations can be achieved. And the safety and comfort of passengers and crew members are improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of an ammonia refrigeration apparatus according to one embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional ammonia refrigeration apparatus.

[Explanation of symbols]

 1. Refrigerator room 2. First plate heat exchanger 3. Second plate heat exchanger 4. Third plate heat exchanger 5. Heat exchanger for air conditioning 6. Seawater pipe 7.・ ・ Seawater pump 8 ・ ・ Circulation pipe 9 ・ ・ Circulation pump 10 ・ ・ Refrigerant pipe 11 ・ ・ Compressor 12 ・ ・ Expansion valve 13 ・ ・ Cold water pipe 14 ・ ・ Cold water pump 15 ・ ・ Blower 16 ・ ・ Spraying device 17 ・ ・Air pipe 18. Electromagnetic valve 19 Spray port 20 Outlet 21 Duct 22 Ventilation fan 23 Inlet

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F25B 49/02 F25B 1/00

Claims (2)

(57) [Claims] 1. A first plate heat exchanger for exchanging heat between seawater flowing through a seawater pipe and heat of fresh water circulating through a circulation pipe, wherein the first plate heat exchanger is heat-exchanged by the first plate heat exchanger. A second plate heat exchanger that exchanges heat between low-temperature fresh water circulating through the circulation pipe and a small amount of refrigerant circulating through the refrigerant pipe and the heat of the refrigerant heated by the compressor. The heat exchanged by the heat exchanger, a small amount of refrigerant circulates through the refrigerant pipe, and the heat of the refrigerant cooled by the expansion valve and the heat of fresh water circulating between the air-conditioning heat exchanger that cools the air. In a refrigerator room in which a third plate heat exchanger for heat exchange is arranged , a pipe is provided above the refrigerator room to blow out compressed air.
An air pipe having a number of spray ports, and compressed air is provided to the air pipe in an open state.
Ventilation or ventilation of compressed air to the air pipe in the closed state
A solenoid valve to be closed; and a solenoid valve provided at a predetermined position above the refrigerator compartment,
Exhaust air and air mixture inside the refrigerator room
A discharge port and a duct, which are provided below the refrigerator compartment and allow air to be supplied from outside the refrigerator compartment.
A leak ammonia removing device for an ammonia refrigeration system, comprising: a suction port for taking in air ; 2. The air or air mixture in the refrigerator room.
Connect the ventilation fan that ventilates the body to the duct and the suction
The leakage ammonia elimination device for an ammonia refrigeration system according to claim 1, wherein the leakage ammonia elimination device is provided in any of the air holes .