JP2000292040A - Method and apparatus for preventing leakage of ammonia - Google Patents

Abstract

PROBLEM TO BE SOLVED: To completely prevent leakage of ammonia of a refrigerant of an ammonia absorption hot and chilled water generator from a load side equipment of an indoor unit. SOLUTION: An ammonia sensor 13 is provided in a secondary refrigerant circulating channel for connecting an evaporator heat exchanger 4a of an ammonia absorption hot and chilled water generator to a load side equipment 10, a detection signal of the sensor is inputted to an automatic controller 21. When the sensor detects the ammonia of a predetermined concentration, the controller 21 stops the operation of the generator, and closes shut-off valves 14, 15 provided in the channel. Simultaneously, by stopping operation of a secondary refrigerant circulating pump 7 or opening a secondary refrigerant discharge valve 16, a harm of the ammonia leakage is further completely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ammonia absorption chiller or an ammonia absorption chiller / heater in which, when ammonia used as a refrigerant leaks into a secondary refrigerant, the ammonia-containing secondary water is subjected to the ammonia mixing. Refrigerant (generally water or brine) circulates and flows to the load side equipment,
The present invention relates to a method for preventing a heat exchanger of a load-side device from being corroded or adversely affecting the health of people around the load-side device, and a device for the same. The ammonia absorption chiller is used as a cooling device or a refrigeration device. By providing a directional control valve for switching the refrigerant flow path, the ammonia absorption chiller can be used for cooling / heating as an ammonia absorption chiller / heater. The present invention is applicable to both the ammonia absorption chiller and the ammonia absorption chiller / heater.

[0002]

2. Description of the Related Art FIG. 6 is a schematic sectional view showing an example of an absorption refrigerator in which an aqueous ammonia solution is circulated in a closed circulation system.
It is explanatory drawing of a function. The aqueous ammonia solution in the generator 1 is heated by the burner 2 and is divided into ammonia vapor and an aqueous ammonia solution. The concentration of the aqueous ammonia solution from which the ammonia vapor has been separated becomes low (for convenience of explanation, this is referred to as dilute aqueous ammonia). The ammonia vapor is guided to the condenser 3 and is cooled by the cooling fan F while flowing through the meandering pipeline acting as a heat exchanger, and is condensed into ammonia liquid. The latent heat of vaporization generated at this time is taken away by the cooling of the cooling fan. The ammonia liquid liquefied in the condenser 3 is decompressed by the expansion valve and sent to the evaporator 4, where it is vaporized in the coiled pipe acting as a heat exchanger to become ammonia vapor. By the above-mentioned vaporization, latent heat of vaporization is taken away, and the temperature of ammonia vapor decreases. On the other hand, the dilute ammonia water formed by generating ammonia vapor in the generator 1 is guided to the upper part of the absorber 5 through the expansion valve, and is rained down from the spray 5s in a shower shape. The ammonia vapor vaporized in the evaporator 4 is also guided into the absorber 5. The absorber 4
The dilute ammonia water that rains inside absorbs the ammonia vapor introduced from the evaporator 4. At this time, the generated latent heat of heat is dissipated into the atmosphere by the cooling fins 5a to prevent the pressure inside the absorber from rising, and the ammonia vapor generated in the evaporator 4 is continuously introduced into the absorber 5. The ammonia aqueous solution that has become concentrated by absorbing the ammonia vapor in the absorber 5 accumulates at the bottom of the absorber 5 and is returned to the generator 1 by the solution pump 6. The returned aqueous ammonia solution is heated by the burner 2 to generate ammonia vapor as described above, and thereafter, these operations are repeated to form a refrigeration cycle. The circulation path formed by connecting the generator 1, the condenser 3, the coil tube in the evaporator 4, and the absorber 5 described above with reference to FIG. 6 forms a closed system, and is strictly airtight. Is kept. In the closed system, ammonia and water repeatedly undergo a phase change between a gas phase and a liquid phase, and accordingly, heat is absorbed and released. Brine (secondary refrigerant) is circulated in the evaporator 4 in which heat is absorbed by the vaporization of the ammonia vapor, and heat exchange is performed with the low-temperature ammonia vapor in the coil tube. The above-mentioned brine is sucked into the secondary refrigerant circulation pump 6, is pressure-fed as shown by an arrow A, and is supplied to a load-side device (for example, a fan coil unit 8). The brine refluxed from the fan coil unit 8 as shown by the arrow B is guided to the vicinity of the top of the evaporator 4 and is allowed to rain. The brine flows down while contacting the outer peripheral surface of the coil tube through which the ammonia vapor flows, and is deprived of heat to a low temperature. As described above, the brine is cooled by the evaporator 4 to a low temperature while being circulated by the secondary refrigerant circulation pump, the heat is absorbed by the fan coil unit, and the temperature is increased. Then, the cooling is performed again, and this function is continuously repeated, thereby performing a cooling (cooling) function of a cooling object (for example, room air) via the fan coil unit.

[0003] Absorption refrigerating machines may cause abnormal operation due to various reasons such as mixing of air and an increase in cooling water temperature. In order to detect or predict such an abnormality, in the related art, a thermometer and a pressure gauge are arranged at a plurality of locations in a pipeline of a circulation system, and a failure is diagnosed based on a temperature and a pressure state. A technique for performing the above-described diagnosis by an automatic arithmetic circuit and a technique for automatically displaying and recording a diagnosis result have been developed and are known. However, it has not yet been studied to detect leakage of ammonia as a refrigerant into brine (or water) as a secondary refrigerant, and to prevent harm based on the detection result.

[0004]

The problem that the cooling and heating functions deteriorate due to damage, aging, or deterioration of some of the equipment constituting the ammonia absorption chiller or the ammonia absorption chiller / heater. Although research has been conducted on improvements in the prior art, the problem that leaked ammonia is toxic must be addressed from a different viewpoint. Ammonia is used as a medicine to neutralize local stimulants, stimulants, and bee venom (formic acid). When ammonia gas is inhaled, it stimulates the nasal mucosa, causing vasoconstriction and blood pressure increase by nerve action. . Also,
It may act on the eyes and cause visual impairment. The maximum permissible limit of ammonia gas in air is set to 1/10000. In FIG. 6 described above, the components drawn by solid lines are generally configured as outdoor units, and the load-side devices 8 drawn by chain lines are configured as outdoor units. For this reason,
Even if ammonia gas leaks in the outdoor unit, it is immediately diffused into the atmosphere, so there is no risk of causing any other serious problem.In contrast, ammonia gas leakage from the outdoor unit causes a poisoning accident. There is no fear. From this point of view, the High Pressure Gas Safety Association's voluntary standard states that ammonia gas is mixed in the secondary refrigerant (generally water or brine (main component water)) that is circulated and sent to the load-side equipment that is an outdoor unit. There must be no harm. " The above voluntary standards divide the ammonia into six stages from the most dangerous mode (a) to the least hazardous mode (f) based on the type of refrigerant system, and on the other hand, Then, based on the application category in which the refrigeration system is to be installed, ammonia is categorized into four stages from application A, which should be severely contraindicated, to application D, which can be the most forgiving, and the above-mentioned style classification (a to
Limiting conditions are defined for each of the combinations of f) and the use categories (A to D).

[0005] Fig. 7 is a chart schematically illustrating the expansion type of the refrigeration, the structure of the refrigerant part, and the structure of the heat exchange part for a to c of the six types of styles in the self-regulation of the refrigeration system. It is. FIG. 8 is a table schematically depicting and comparing the expansion type of the refrigerant, the structure of the refrigerant part, and the structure of the heat exchange part with respect to d to f of the six style divisions in the self-regulation of the refrigeration system. Among the application categories to be considered in comparison with the above chart, in the application category A including hospitals, nurseries, etc., from the direct inflation type of the style category a to the indirect inflation / sealing type of the style category d are unconditionally prohibited. In addition, the indirect expansion / ventilation closed type of the mode category e and the double indirect expansion type of the mode category f are allowed with a limited amount of refrigerant charging. In the use category B including theaters, department stores, hotels, and the like, among the use categories, the condition that the refrigerant charging amount is 2.5 kg or less is applied to the style categories a to d. The capacity of kilograms is equivalent to a large type for residential use or a minimum type for business use, and is strictly strictly prohibited except for general residential use. In the use category C including the office and the factory and the use category D including the refrigerated warehouse, the use category is eased as compared with the use category B, but even in these use categories C and D, As for the air conditioning equipment for improving the living environment of humans, the amount of refrigerant charged is limited to 2.5 kilograms or less as in the above-described application category B.

[0006] Summarizing the above self-regulation in a very general manner and extracting matters related to the present invention, the indirect inflation / sealing type of the style division d and the indirect inflation / ventilation sealing of the style category e are classified into two types. There are strict walls (indicated by thick dividing lines) between them, and depending on the style above this wall, medium and large air conditioners cannot be manufactured. The present invention has been made in view of the above circumstances, and is applied to an indirect expansion / closed type (d) ammonia absorption chiller / heater, and has a safety comparable to the indirect expansion / ventilation closed type (e). It is an object of the present invention to provide a technology for preventing harm of ammonia leakage, which can obtain the following. When the present invention is applied to the indirect expansion / ventilation sealing type (e), its safety can be further improved.

[0007]

The basic principle of the present invention created to achieve the above object will be briefly described with reference to FIG. 1 corresponding to an embodiment of the present invention. In order to completely prevent ammonia, which is a refrigerant, from leaking from the load-side device 10 as an indoor unit, a secondary connecting the evaporator heat exchange section 4a of the ammonia absorption chiller / heater to the load-side device 10 is connected. An ammonia sensor 13 is provided in the refrigerant circulation channel, and a detection signal of the ammonia sensor is input to the automatic control device 21. When the ammonia sensor detects a predetermined concentration of ammonia, the operation of the ammonia absorption chiller / heater is stopped. And a shut-off valve 1 provided in the secondary refrigerant circulation passage.
Close 4,15. In conjunction with this, the secondary refrigerant circulation pump 7
By stopping the operation of the fuel cell and opening the secondary refrigerant discharge valve 16, it is possible to more completely prevent the danger of ammonia leakage.

[0008] Based on the principle described above, claim 1
The configuration of the method according to the present invention is a generator that generates an ammonia vapor by heating an aqueous ammonia solution, a means for heating the generator, a condenser that cools and liquefies the ammonia vapor generated by the generator, An evaporator that evaporates the ammonia liquid while exchanging heat with the ammonia liquid generated by the condenser and the secondary refrigerant, and an ammonia vapor that is vaporized by the evaporator are referred to as "the ammonia vapor in the generator. Aqueous ammonia solution diluted by its generation "
An absorber for absorbing ammonia vapor in the absorber, a solution pump for returning and circulating a concentrated aqueous ammonia solution to the generator, and receiving heat exchange in the evaporator. A refrigerant circulating pump for sucking and discharging the secondary refrigerant and circulating the secondary refrigerant, and a load-side device for receiving the secondary refrigerant circulating therethrough, or an ammonia absorption chiller or a component flowing through the above-described components. In the ammonia absorption chiller / heater further comprising a directional control valve for switching the path, the secondary refrigerant which receives heat exchange in the evaporator and is sent to the load side device is preferably used in the evaporator heat exchange unit. In the vicinity of the outflow port, the presence or absence of "change in the electrical properties of the secondary refrigerant or change in the chemical or physical properties caused by mixing of ammonia into the secondary refrigerant" is monitored. Detects contamination In this case, the operation of the secondary refrigerant circulation pump is stopped, the flow of the secondary refrigerant in the load-side device is stopped, the heating of the generator is stopped to suppress the generation of ammonia vapor, and the solution pump is stopped. It is characterized by stopping the operation. According to the above-described method of the first aspect of the present invention, when ammonia leaks and mixes into the secondary refrigerant in the heat exchange section of the evaporator, electrical, chemical, or Since the physical change is monitored, the leak of ammonia is immediately and reliably detected. The above-described monitoring of ammonia leakage is performed during the supply of the secondary refrigerant from the evaporator to the load-side device, and the operation of the secondary refrigerant circulation pump is stopped when leakage or mixing of ammonia is detected. And the flow of the secondary refrigerant in the load-side equipment is stopped.
The secondary refrigerant affected by the mixing of ammonia in the heat exchange section of the evaporator does not reach the load side equipment. Among the reasons that ammonia is contraindicated to be mixed into the secondary refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment. This is because the copper pipes that are used are attacked by ammonia and the ammonia is toxic and causes eye and respiratory problems. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

According to a second aspect of the present invention, in addition to the constituent elements of the first aspect of the present invention, at the same time as the operation of the secondary refrigerant circulation pump is stopped or immediately after the operation is stopped, The flow of the secondary refrigerant in the circulation path is completely shut off by the valve means, and the secondary refrigerant containing ammonia is removed.
It is characterized in that the next refrigerant is not allowed to flow into the load side equipment. According to the second aspect of the present invention described above, the secondary refrigerant circulating flow is stopped by stopping the secondary refrigerant circulating pump.
By doing so more reliably, the reliability of ensuring safety can be improved. There are various types of liquid pumps. When the pump stops, there is a type that almost completely shuts off between the suction port and the discharge port of the pump (for example, a piston pump). There is also a pump (for example, a centrifugal pump or the like) in which a connection between a suction port and a discharge port is made in a pump. At the moment when the entrainment of the secondary refrigerant circulation pump driving motor is cut off by detecting the incorporation of ammonia, the secondary refrigerant circulation pump also has rotational inertia, and the secondary refrigerant also has flow energy. There are 2
Even if the drive motor is de-energized to stop the secondary refrigerant circulation pump, the circulating flow of the secondary refrigerant does not always stop immediately. Therefore, in the ammonia absorption chiller / heater having a configuration in which the circulating flow of the secondary refrigerant is continued for a while after the pump stops, when the circulating flow of the secondary refrigerant is shut off by the valve means by applying the second aspect, Maintenance of safety is further ensured. If the valve closing operation timing of the valve means precedes the stop of the secondary refrigerant circulation pump, there is a possibility that an abnormally high pressure may occur in a part of the secondary refrigerant circulation flow path. Is performed at the same time as or immediately after the stop of the secondary refrigerant circulation pump, so that there is no possibility of generating an abnormally high pressure.

A third aspect of the present invention provides a method according to the first or second aspect of the present invention, further comprising a lowest point in the circulation path of the secondary refrigerant or a part similar thereto. A secondary refrigerant discharge valve is provided in
At the highest point in the circulation path of the secondary refrigerant or at a place similar thereto, an open expansion tank is provided, or an atmosphere release valve is provided to stop the operation of the secondary refrigerant circulation pump. , Air is introduced from the above-mentioned open type expansion tank or air release valve and the discharge valve is opened,
It is characterized in that the secondary refrigerant is discharged from the circulation flow path, and the secondary refrigerant is not left at least in the load-side device. According to the invention method of the third aspect described above, not only does the flow of the secondary refrigerant in the load-side device be cut off, but the secondary refrigerant in the load-side device is discharged and removed from the load-side device. The danger of leaking ammonia from the load-side device, which is an indoor unit, into the room is completely eliminated. In this case, not only the discharge valve is opened but also smooth discharge of the secondary refrigerant is not performed unless air at atmospheric pressure is introduced into the secondary refrigerant flow path in the load-side device. However, an open expansion valve is provided. If it is, it acts as an air inlet. Therefore, in the present invention, when the above-mentioned open type expansion valve is not provided, an air release valve for opening and communicating the secondary refrigerant circulation path to the atmosphere is provided so that the secondary refrigerant in the load-side device can be quickly supplied. So that it can be discharged to

According to a fourth aspect of the present invention, there is provided a generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, and cooling the ammonia vapor generated by the generator. A condenser to liquefy,
An evaporator that evaporates the ammonia liquid while exchanging heat with the ammonia liquid generated by the condenser and the secondary refrigerant, and an ammonia vapor that is vaporized by the evaporator are referred to as "ammonia vapor in the generator. An absorber that absorbs into the `` aqueous ammonia aqueous solution that has been diluted '' and a solution pump that absorbs the ammonia vapor in the above absorber and returns the concentrated aqueous ammonia solution to the generator and circulates it. A secondary refrigerant circulation pump for sucking, discharging, and circulating the secondary refrigerant having undergone heat exchange in the evaporator;
A load-side device that receives a circulating supply of the next refrigerant, or an ammonia-absorbing chiller-heater comprising the above components and a directional control valve for switching a flow path. Regarding the secondary refrigerant in the open tank provided in the middle of the circulation flow path of the secondary refrigerant, "the change in the electrical properties of the secondary refrigerant, which occurs when ammonia is mixed into the secondary refrigerant, or Change of chemical or physical properties "to monitor the presence or absence, if ammonia contamination is detected, stop the operation of the secondary refrigerant circulation pump,
The method is characterized in that the flow of the secondary refrigerant in the load-side device is stopped, the heating of the generator is stopped to suppress the generation of ammonia vapor, and the operation of the solution pump is stopped. According to the method of the invention described above, when ammonia leaks and mixes into the secondary refrigerant in the heat exchange section of the evaporator, the secondary refrigerant is electrically, chemically, or chemically mixed by the ammonia. Since the physical change is monitored, the leak of ammonia is immediately and reliably detected. In addition, since the mixing of ammonia in the open tank is monitored, the monitoring of ammonia is performed under the atmospheric pressure, and the monitoring can be performed by a non-pressure-resistant ammonia sensor. Monitoring of the ammonia leak above
The operation is performed in an open tank provided in the middle of the secondary refrigerant supply from the evaporator to the load side device, and the operation of the secondary refrigerant circulation pump is stopped when leakage or mixing of ammonia is detected. Then, since the flow of the secondary refrigerant in the load-side device is stopped, the secondary refrigerant affected by the mixing of ammonia in the heat exchange section of the evaporator does not reach the load-side device. Among the reasons that ammonia is contraindicated to be mixed into the secondary refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment. This is because the copper pipes that are used are attacked by ammonia and the ammonia is toxic and causes eye and respiratory problems. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

A fifth aspect of the present invention provides a method for generating ammonia vapor by heating an aqueous ammonia solution, means for heating the generator, and cooling the ammonia vapor generated by the generator. A condenser to liquefy,
An evaporator that evaporates the ammonia liquid while exchanging heat with the ammonia liquid generated by the condenser and the secondary refrigerant, and an ammonia vapor that is vaporized by the evaporator are referred to as "ammonia vapor in the generator. An absorber that absorbs into the `` aqueous ammonia aqueous solution that has been diluted '' and a solution pump that absorbs the ammonia vapor in the above absorber and returns the concentrated aqueous ammonia solution to the generator and circulates it. A secondary refrigerant circulation pump for sucking, discharging, and circulating the secondary refrigerant having undergone heat exchange in the evaporator;
A load-side device that receives a circulating supply of the next refrigerant, or an ammonia-absorbing chiller-heater comprising the above components and a directional control valve for switching a flow path. Regarding the secondary refrigerant in the open tank provided in the middle of the circulation path of the secondary refrigerant, "the change in the electrical properties of the secondary refrigerant, which occurs when ammonia is mixed into the secondary refrigerant, or Monitoring the presence or absence of a change in chemical or physical properties, and if ammonia contamination is detected, introduces the secondary refrigerant in the open tank into the load-side equipment while continuing to operate the secondary refrigerant circulation pump. And the pipe for introducing the secondary refrigerant in the load-side device into the heat exchange section inlet of the evaporator is shut off by closing the valve means, and the secondary refrigerant circulation pump sucks the pipe. Evaporates the discharged secondary refrigerant The heat exchanger and the open tank of the vessel are circulated and circulated, and the "bypass valve connected in parallel with the load-side equipment" is circulated. According to the above-described method of the present invention, when ammonia leaks and mixes into the secondary refrigerant in the heat exchange section of the evaporator, the ammonia is mixed with ammonia.
Since the electrical, chemical, or physical change of the secondary refrigerant is monitored, the leak can be detected immediately and reliably.
The above-described monitoring of the ammonia leakage is performed in an open tank provided in the middle of the secondary refrigerant supply from the evaporator to the load side device, and when the leakage or mixing of ammonia is detected, While continuing the operation of the secondary refrigerant circulation pump, the flow path of the secondary refrigerant is switched and circulated to the open tank and the evaporator heat exchange unit, and the load side device is bypassed. The secondary refrigerant affected by ammonia does not reach the load-side device.
The secondary refrigerant affected by the mixing of ammonia is circulated through the open tank, where the ammonia is diffused into the atmosphere and the ammonia concentration is reduced. 2
Among the reasons contraindicated in mixing ammonia into the next refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment Copper pipes are attacked by ammonia,
Also, the ammonia is toxic and causes damage to eyes and respiratory organs. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

According to a sixth aspect of the present invention, there is provided a generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, and cooling the ammonia vapor generated by the generator. A condenser to liquefy,
An evaporator that evaporates the ammonia liquid while exchanging heat with the ammonia liquid generated by the condenser and the secondary refrigerant, and an ammonia vapor that is vaporized by the evaporator are referred to as "ammonia vapor in the generator. An absorber that absorbs into the `` aqueous ammonia aqueous solution that has been diluted '' and a solution pump that absorbs the ammonia vapor in the above absorber and returns the concentrated aqueous ammonia solution to the generator and circulates it. A secondary refrigerant circulation pump for sucking, discharging, and circulating the secondary refrigerant having undergone heat exchange in the evaporator;
A load-side device that receives a circulating supply of the next refrigerant, or an ammonia-absorbing chiller-heater comprising the above components and a directional control valve for switching a flow path. An ammonia sensor that detects a change in the electrical properties of the secondary refrigerant when ammonia is mixed in the secondary refrigerant, or an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or the secondary refrigerant An ammonia sensor for detecting a change in physical properties of the ammonia sensor is provided, and an automatic control device for receiving an output signal of the ammonia sensor and controlling the secondary refrigerant circulation pump is provided. When the value reaches a predetermined ammonia concentration, a command signal for the automatic control device to stop the operation of the secondary refrigerant circulation pump,
And a command signal for stopping the operation of the means for heating the generator, and a command signal for stopping the operation of the solution pump, and the ammonia absorption chiller or the ammonia absorption chiller / warmer. In the secondary refrigerant circulation pipe connecting the evaporator heat exchange section and the load side equipment of the heat exchanger, in the middle of the pipe from the outlet of the evaporator heat exchange section to the inlet of the load side equipment, The above-mentioned ammonia sensor is connected near the evaporator heat exchange section, and is characterized in that it is connected. According to the apparatus of the sixth aspect described above, ammonia is contained in the secondary refrigerant in the evaporator heat exchange section (which may function as a condenser heat exchange section) of the ammonia absorption chiller or the ammonia absorption chiller / heater. When leaked and mixed, the ammonia sensor detects the leak of ammonia, and the automatic control device operates to stop the heating of the ammonia aqueous solution in the generator, and the circulation of the secondary refrigerant is stopped.
There is no fear that the secondary refrigerant mixed with ammonia reaches the load-side device. The load-side equipment is generally an indoor unit, and is affected by ammonia because its heat exchanger pipe is made of copper. For this reason, it is extremely undesirable for the secondary refrigerant containing ammonia harmful to the human body to flow through the load-side device. Further, according to the device of the present invention, the danger that the ammonia-containing secondary refrigerant flows through the load-side device is completely prevented.

According to a seventh aspect of the present invention, in addition to the constituent elements of the sixth aspect of the present invention, the evaporator heat exchange section of the ammonia absorption chiller or the ammonia absorption chiller / heater and the load-side equipment are provided. A shut-off valve that is electromagnetically opened and closed is inserted and connected in the middle of the secondary refrigerant circulation line that connects the above, and when the detection value of the ammonia sensor reaches a predetermined ammonia concentration, An automatic controller outputs a command signal for closing the shut-off valve, thereby eliminating the forced circulation flow of the secondary refrigerant in the load equipment. According to the device of the seventh aspect described above, the effect of preventing harm in the device of the sixth aspect is further ensured. In other words, in the device according to claim 6, when ammonia is detected in the secondary refrigerant by the ammonia sensor,
The operation of the secondary refrigerant circulating pump is stopped to prevent the ammonia-containing secondary refrigerant from circulating and flowing to the load-side device. Thus, the flow of the secondary refrigerant in the secondary refrigerant circulation line is completely blocked by closing the shutoff valve. For this reason, the flow continuation due to the rotational inertia of the pump and the flow energy of the circulating flow is prevented, and the flow of the secondary refrigerant is immediately stopped.

According to an eighth aspect of the present invention, in addition to the constituent elements of the seventh aspect of the present invention, in addition to the constituent elements of the seventh aspect of the present invention, the secondary refrigerant circulation line connecting the evaporator heat exchange section and the load-side equipment is provided. Is provided with an expansion tank, and / or an electromagnetically actuated air release valve is connected thereto, and preferably at least the load-side device is located at the lowest point in the secondary refrigerant circulation line. An electromagnetically operated secondary refrigerant discharge valve is provided at a position lower than the secondary refrigerant flow path, and when the detection value of the ammonia sensor reaches a predetermined ammonia concentration, the automatic control device A command signal for opening the secondary refrigerant discharge valve is output, and when the expansion tank is not provided, the air release valve is used together with the above-mentioned secondary refrigerant discharge valve opening command signal. Command signal to open And force, characterized in that so allowed to naturally flow out of the load-side apparatus secondary refrigerant of the load in the device by gravity. Claim 8 described above.
According to the device of the invention, it is possible to more completely prevent the corrosion of the heat exchange pipe of the load-side device and the ammonia leakage from the load-side device. That is, when it is detected that ammonia leaks or mixes into the secondary refrigerant, the operation of the secondary refrigerant circulation pump is stopped or the circulation flow of the secondary refrigerant is stopped by a shut-off valve, so that ammonia leakage is caused. In this claim, the secondary refrigerant in the load-side device is discharged, and the entire amount of the secondary refrigerant in the secondary refrigerant flow path of the load-side device is replaced with air. The effect of harm prevention is more complete.

According to a ninth aspect of the present invention, there is provided a generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, and cooling the ammonia vapor generated by the generator. A condenser to liquefy,
An evaporator that evaporates the ammonia liquid while exchanging heat with the ammonia liquid generated by the condenser and the secondary refrigerant, and an ammonia vapor that is vaporized by the evaporator are referred to as "ammonia vapor in the generator. An absorber that absorbs into the `` aqueous ammonia aqueous solution that has been diluted '' and a solution pump that absorbs the ammonia vapor in the above absorber and returns the concentrated aqueous ammonia solution to the generator and circulates it. A secondary refrigerant circulation pump for sucking, discharging, and circulating the secondary refrigerant having undergone heat exchange in the evaporator;
A load-side device that receives a circulating supply of the next refrigerant, or an ammonia-absorbing chiller-heater comprising the above components and a directional control valve for switching a flow path. An ammonia sensor that detects a change in the electrical properties of the secondary refrigerant when ammonia is mixed in the secondary refrigerant, or an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or the secondary refrigerant An ammonia sensor for detecting a change in physical properties of the ammonia sensor is provided, and an automatic control device for receiving an output signal of the ammonia sensor and controlling the secondary refrigerant circulation pump is provided. When the value reaches a predetermined ammonia concentration, a command signal for the automatic control device to stop the operation of the secondary refrigerant circulation pump,
And a command signal for stopping the operation of the means for heating the generator, and a command signal for stopping the operation of the solution pump, and the ammonia absorption chiller or the ammonia absorption chiller / warmer. In the secondary refrigerant circulation pipe connecting the evaporator heat exchange section of the heat exchanger and the load side equipment, "2" in the middle of the pipe from the outlet of the evaporator heat exchange section to the inlet of the load side equipment. An open tank that has an inflow portion for the next refrigerant and an outflow portion separated from the inflow portion, and is not shielded from the atmosphere. It is characterized in that it detects ammonia in the secondary refrigerant or in the secondary refrigerant in the pipeline near the open tank.
According to the above-described device of the ninth aspect, when ammonia leaks and mixes into the secondary refrigerant in the evaporator heat exchange section, the secondary refrigerant circulates and flows into the open tank first. Then, the mixture of ammonia is detected by the ammonia sensor. When the entry of ammonia is detected, the secondary refrigerant circulation pump is stopped by the operation of the automatic control device, and the circulation flow of the secondary refrigerant disappears before the ammonia-containing secondary refrigerant reaches the load-side device. At this time, since a substantial amount of the secondary refrigerant is stored in the open tank, the secondary refrigerant flows into the open tank, is diluted, the flow velocity is reduced, and slowly flows toward the open tank outlet. . For this reason, there is a large time margin for the ammonia sensor to detect the entry of ammonia and for the automatic control device to stop the secondary refrigerant circulation pump or stop the heating of the generator to suppress the generation of ammonia vapor. . In addition, a non-pressure-resistant ammonia sensor can be used, so an inexpensive sensor is sufficient.

According to a tenth aspect of the present invention, there is provided a generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, and cooling the ammonia vapor generated by the generator. A condenser for liquefaction, an evaporator for evaporating the ammonia liquid while exchanging heat between the ammonia liquid and the secondary refrigerant generated in the condenser, and an ammonia vapor vaporized by the evaporator, An absorber that absorbs into the ammonia aqueous solution that has become diluted due to the generation of ammonia vapor in the vessel, and the ammonia aqueous solution that has absorbed the ammonia vapor in the above-mentioned absorber and returned to the above-described generator. A solution pump for circulating the secondary refrigerant, a secondary refrigerant circulating pump for sucking and discharging the secondary refrigerant having undergone heat exchange in the evaporator, and circulating the secondary refrigerant. Receiving load-side equipment, and an ammonia absorption chiller / water heater comprising: or an ammonia absorption chiller / heater configured by adding a directional control valve for switching a flow path to the above-described components, wherein ammonia is contained in the secondary refrigerant. When mixed, an ammonia sensor that detects a change in the electrical properties of the secondary refrigerant, or an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or a change in the physical properties of the secondary refrigerant An ammonia sensor to be detected is configured, and an automatic control device to which a signal detected by the ammonia sensor is input is provided, and at least one of a secondary refrigerant inflow portion and a secondary refrigerant outflow portion of the load-side device is provided. Provided on one side, and when the detection value of the ammonia sensor reaches a predetermined ammonia concentration, the valve is closed by the automatic control device. An electromagnetically operated shut-off valve, and an electromagnetically operated shut-off valve that is connected in parallel with the load-side device and is opened by the automatic control device when a predetermined ammonia concentration is reached, and In the secondary refrigerant circulation line connecting the evaporator heat exchange part of the ammonia absorption chiller or the ammonia absorption chiller / heater and the load side equipment, the outlet of the evaporator heat exchange part is connected to the inlet of the load side equipment. In the middle of the pipeline leading to, "an open tank that has an inflow portion of the secondary refrigerant and an outflow portion separated from the inflow portion and is not shielded from the atmosphere" is provided, An ammonia sensor detects ammonia in the secondary refrigerant in the open tank or in the secondary refrigerant in a pipe near the open tank. According to the device of the tenth aspect described above, when ammonia is mixed in the secondary refrigerant, the ammonia sensor detects this, the automatic control device opens and closes the valve mechanism, and the secondary refrigerant is The load-side device is bypassed. That is, the load-side device is separated from the circulation flow of the secondary refrigerant, and the danger of ammonia leaking from the load-side device is completely prevented. The secondary refrigerant that has bypassed the load-side equipment is circulated and flows between the evaporator heat exchange section and the open tank, and comes into contact with the atmosphere in the open tank to emit ammonia vapor. Is suppressed.

According to an eleventh aspect of the present invention, in addition to the constituent elements of the sixth to tenth aspects of the present invention, the automatic control device includes a detection signal of an ammonia sensor and a diagnosis start trigger signal. An input unit for inputting
A storage unit for storing data, a calculation unit for calculating a judgment value based on a change in past data, a comparison unit for comparing and judging a judgment value and a current value, and comparing stored data in a time series to reduce sensor deterioration. A sensor self-diagnosis unit for judging, and an output unit for outputting a signal to the outside, and the output unit includes an ammonia leak alarm, an ammonia sensor deterioration alarm, a diagnosis mode, and a stop of a chiller or a chiller / warmer. Signal 2
It has a function of outputting at least one or more of a next refrigerant circulation pump stop signal, a shutoff valve closing signal, and a discharge valve opening signal. According to the apparatus of the eleventh aspect described above, the method of the inventions according to the first to fifth aspects can be automatically performed, and the effect thereof can be sufficiently exhibited. In particular, not only can the harm prevention device be automatically operated, but also the operation status of the harm prevention device can be displayed in real time as needed, and maintenance advice information can be displayed.

[0019]

FIG. 2 is a schematic piping system diagram showing three examples of an embodiment of a harm prevention device configured to carry out a method for harm prevention of ammonia leakage according to the present invention, and a control system is additionally shown. (A) depicts the most basic embodiment, (B) depicts an embodiment in which a shut-off valve is provided in the circulation path of the secondary refrigerant, and (C) depicts the secondary refrigerant. An embodiment provided with a means for discharging to the outside of the circulation system is illustrated. FIG. 2 (A),
The heat exchange part of the evaporator described with reference to FIGS. 7 and 8 is shown with a reference numeral 4a in common with (B) and (C). This is a device where heat exchange is performed. Therefore, it is a place where it cannot be said that there is no opportunity for ammonia to leak into the two-phase refrigerant. In the present invention, even when ammonia leaks at this location, the ammonia-containing 2 Do not allow the next refrigerant to reach. This figure 2 (A), (B), (C)
Is a secondary refrigerant circulation pump,
The next refrigerant circulates and flows as indicated by arrows i and j. Reference numeral 13 denotes an ammonia sensor. As the ammonia sensor of the present example, a known instrument of a type that detects the mixing of ammonia by measuring the electric conductivity of the secondary refrigerant is applied. In addition, for example, a well-known instrument of a type that measures Ph to detect mixing of ammonia can be applied.
A well-known instrument of a type for measuring physical properties such as vapor pressure equilibrium may be used. In short, it suffices if the change in the electrical properties of the secondary refrigerant or the change in the chemical or physical properties caused by the incorporation of ammonia can be monitored to detect the incorporation of ammonia into the secondary refrigerant. However, since the secondary refrigerant contains impurities, and the content may change irregularly, it is hardly affected by the contained impurities or the effect can be corrected. It is desirable to use properties (for example, electrical conductivity, hydrogen ion concentration, etc.) that change to In addition, even if the property is affected by impurities, it can be used if the influence of the impurities is known in advance and a change can be clearly detected by mixing ammonia.

The output signal of the ammonia sensor 13 is input to the automatic control device 21. The detailed structure of this automatic control device will be described later with reference to FIG. (FIG. 2 (A)
When the detection value of the ammonia sensor 13 reaches a predetermined ammonia concentration, the automatic control device 21 stops the outdoor unit part (the constituent part shown in FIG. 6 described above) of the ammonia absorption chiller / heater, The secondary refrigerant circulation pump 7 is stopped. The above-mentioned "predetermined ammonia concentration" means "predetermined set value", and since this set value indicates that the ammonia concentration has reached a certain value, the "ammonia concentration" (Hereinafter the same). In the present embodiment, the stop of the absorption chiller / heater (FIG. 6) is not a so-called emergency stop, but a normal stop operation, so that the burner 2 is stopped and the solution pump 6 is stopped. The reason is that the application of the present invention prevents harm related to ammonia leakage, so that even if ammonia is mixed in the secondary refrigerant, it is not enough to perform an emergency stop. As understood from FIG. 2 (A), when the secondary refrigerant mixed with ammonia in the evaporator heat exchange part 4a flows in the direction of arrow i, the ammonia refrigerant 13 As a result, ammonia mixing is detected and the circulating flow can be stopped, so that there is no possibility of leakage from the load-side device 10, which is an indoor unit, indoors.

In the example of FIG. 2B, the aforementioned FIG.
In addition to the structural functions described above, a forward shutoff valve 14 and a return shutoff valve 15 are interposed and connected in the circulation flow path of the secondary refrigerant, and when ammonia contamination is detected, the shutoff valves 14 and 15 are closed. Is ventured. Generally, when the ammonia absorption chiller / heater is operating normally, the circulating flow of the secondary refrigerant has inertia,
Since the secondary refrigerant circulation pump 7 has rotary inertia, the circulation flow of the secondary refrigerant may not immediately disappear even if the drive motor (not shown) of the secondary refrigerant circulation pump is turned off. When the shut-off valve is provided as in the embodiment of FIG. (B), when the ammonia leakage is detected, the circulation flow of the secondary refrigerant is immediately lost, and the ammonia-containing secondary refrigerant reaches the load-side device 10. Can be completely prevented.
FIG. 2 (C) shows an example in which the safety is further enhanced as compared with the above-mentioned FIG. 2 (B). In addition to the configuration shown in FIG. A secondary refrigerant discharge valve 16 is provided at a position lower than the secondary refrigerant flow path of the load-side device 10). At the same time as closing the shutoff valves 14 and 15, the secondary refrigerant discharge valve 16 is opened and the load-side device 10 is opened.
The secondary refrigerant inside is discharged. Thereby, the load-side device 10
Prevention of ammonia from leaking is absolutely necessary. However,
In order to allow the secondary refrigerant in the load-side device 10 to flow out smoothly and quickly from the secondary refrigerant discharge valve 16, the open expansion tank 1
The presence of one is required. For example, when a closed expansion tank 11 'as shown in FIG. 1A is used, an atmosphere release valve 19 is provided at the highest point in the secondary refrigerant circulation line or at a position similar thereto. When the secondary refrigerant discharge valve 16 is opened, the atmosphere release valve 19 is also opened. As a result, the secondary refrigerant in the load-side device 10 is replaced with air, and flows down into the secondary refrigerant processing tank 17. If the secondary refrigerant processing tank 17 is provided in a place with good ventilation outdoors, and it is permissible to gradually diffuse the ammonia contained in the secondary refrigerant into the atmosphere, long-term diffusion is required. If the ammonia concentration is lowered, it may be possible to discharge the sewage. Depending on the circumstances, it can be rendered harmless by adding an ammonia neutralizing agent.

FIG. 1 is a system diagram schematically illustrating a typical embodiment of a hazard prevention device for ammonia leakage according to the present invention. The automatic control device 21 receives a detection signal from the ammonia sensor 13, and outputs the outdoor unit portion (corresponding to FIG. 6) of the ammonia absorption chiller / heater, the forward cutoff valve 14, and the return cutoff valve 1.
5, a command signal is given to the secondary refrigerant circulation pump 7, the secondary refrigerant discharge valve 16, and the atmosphere release valve 19.

FIG. 3 is a system diagram showing an embodiment different from the above-mentioned FIG. 3, in which the present invention is applied to an ammonia absorption chiller / heater having an open tank. An example of a method for automatically controlling the pump is described.
An example of a system provided with a secondary refrigerant discharge valve is illustrated. The reference numeral 8 denotes an open tank, which is located in the circulation path of the secondary refrigerant, in the middle of the flow path from the evaporator heat exchanger 4a to the load-side device 10, preferably near the evaporator heat exchanger 4a. Provided. The open tank 8 is a component similar to the expansion tank 11 shown in FIGS. 1 and 2 described above. However, in the expansion tank 11, the inlet and outlet of the secondary refrigerant are the same. If the liquid level in the expansion tank 11 does not change, the flow of the secondary refrigerant does not occur in the tank. In contrast, the open tank 8 has an inflow portion and an outflow portion separated from each other. The secondary refrigerant inside is flowing.

An ammonia sensor 13 is provided in the open tank 8 as close to the inlet of the secondary refrigerant as possible. Although not shown, as a modified example of the present embodiment, an ammonia sensor 13 can be provided near the open tank 8 and provided in the circulation line of the secondary refrigerant (for example, an ammonia sensor is provided near point s in the figure). May be). The detection signal of the ammonia sensor 13 is input to the automatic control device 21, which controls the outdoor unit of the ammonia absorption chiller / heater and the secondary refrigerant circulation pump 7.

Considering the embodiment of FIG. 3A in comparison with the embodiment of FIG. 2A described above, an open tank 8 is provided instead of the sealed expansion tank 11 'of the previous example. The other points are the same or similar. When the ammonia sensor 13 is provided in or near the open tank, the ammonia sensor does not need to be a pressure-resistant type. Therefore, it is economical because an inexpensive non-pressure resistant ammonia sensor is sufficient. In this case, the ammonia sensor 13 can be provided above the liquid level in the open tank.

In the embodiment of FIG. 3B, a secondary refrigerant discharge valve 16 and a secondary refrigerant processing tank 17 are added as compared with the embodiment of FIG. 3A. These constituent members are the same or similar to those in FIG. 2C described above. However, in the embodiment of FIG. 3B, since the open tank 8 is provided, the atmosphere release valve 19 cooperating with the secondary refrigerant discharge valve 16 (see FIG. 2C).
The air can be introduced into the load-side device 10 without providing the air conditioner. Other operations are the same as those in FIG.

FIG. 4 is a piping system diagram showing another embodiment different from the above, but the illustration of the control system is omitted due to space limitations. FIG. 4A shows an open tank, a shutoff valve, and a bypass valve. (B) depicts a method in which an air release valve and a secondary refrigerant discharge valve are further provided. In FIG. 4, an automatic control device 21 similar to that in FIG. 3 described above is provided, and a detection signal of the ammonia sensor 13 is input. The harm prevention device of this embodiment is operated as follows by the automatic control device (not shown). (See FIG. 4 (A).) When the ammonia sensor 13 does not detect the incorporation of ammonia and the outdoor unit of the ammonia absorption chiller / heater is operating normally, the outgoing side of the circulation line of the secondary refrigerant (evaporation) The forward shutoff valve 14 connected to the pipeline of the heat exchanger 4a to the load side device 10) is open and connected in parallel to the load side device and the forward shutoff valve 14. The bypass valve 18 is closed. As a result, the apparatus according to the present embodiment normally performs the normal cooling and heating functions without being affected by the addition of the outward path shutoff valve 14 and the bypass valve 18.

When the ammonia sensor 13 detects the incorporation of ammonia, the outgoing cutoff valve 14 is closed while the operation of the secondary refrigerant circulating pump 7 is continued without stopping the operation (the blacked out portion in FIG. ), And the bypass valve 18 is opened (open in the figure indicates opening). Thereby, as easily understood from the figure, the secondary refrigerant circulates through the open tank 8 as shown by the arrow m without flowing through the load-side device 10. At the same time, the outdoor unit of the ammonia absorption chiller / heater is normally stopped (not an emergency stop) as in the embodiment of FIG. 2 described above, the heating of the generator is stopped, and the generation of ammonia vapor is suppressed. . On the other hand, since the secondary refrigerant circulation flow indicated by the arrow m is continued, the ammonia mixed in the secondary refrigerant diffuses into the atmosphere when flowing through the open tank, and the ammonia concentration in the secondary refrigerant gradually decreases. The embodiment shown in FIG. 4B is different from the embodiment shown in FIG. 4A in that a return path shutoff valve 15 and a secondary refrigerant discharge valve 16 are added. These two valves are the same components as those in the embodiment of FIG. 2C, and the secondary refrigerant discharge valve 16 is
A secondary refrigerant processing tank 17 is provided. This embodiment (FIG. 4)
In (B)), an open tank 8 is provided.
4, the air release valve 19 for introducing air to be replaced with the secondary refrigerant in the load side device 10.
Is provided. According to the embodiment of FIG. 4B, since the secondary refrigerant in the load-side device 10 is discharged, FIG.
The harm prevention of ammonia leakage from the load-side device 10 is more perfect than the embodiment of FIG.

FIG. 5 is a block diagram showing the configuration of the automatic control device shown in FIGS. 1 and 2 and input signals. A detection signal from the ammonia sensor 13 is input to the input unit 21a, and an operation signal of the secondary refrigerant circulation pump 7 is input as a diagnosis start trigger signal (while the chiller / heater is stopped). To avoid unnecessary monitoring). The storage unit 21b stores the data, and the calculation unit 21c calculates the determination value based on the past data fluctuation. The comparison unit 21d compares and determines the determination value and the current value. The sensor self-diagnosis unit 21e compares the stored data in a time series to determine whether or not the ammonia sensor has deteriorated and its degree. The output unit 21f outputs a command signal to devices to be controlled based on the determination in the comparison unit 21d. In response to the diagnostic mode 21h, the display unit 21g displays an operation state such as "during determination", "monitoring", or "during discharge of secondary refrigerant". As described above, the operation signal of the secondary refrigerant circulation pump 7 is used as a trigger signal for starting diagnosis (monitoring). However, even after the leakage of ammonia is detected, the operation of the secondary refrigerant circulation pump 7 is stopped. Since the diagnostic operation must be continued, the external output after detecting the ammonia contamination is a self-holding circuit (not shown).
Thus, the output is made even after the secondary refrigerant pump is stopped. When an electric conductivity measuring instrument is used as the ammonia sensor, the electric conductivity of the secondary refrigerant varies depending on “temperature” and “additive of secondary refrigerant” or “impurity of secondary refrigerant”. The characteristics related to the electric conductivity etc. of the ammonia absorption chiller / heater are stored for a certain period,
A judgment value is calculated based on the fluctuation state, the calculated value is compared with a current value, and a signal is output to the outside.

[0030]

As described above, according to the embodiment of the present invention, the structure and function of the present invention are clarified. According to the method of the present invention, ammonia is contained in the secondary refrigerant in the heat exchange section of the evaporator. Is leaked and mixed, the electrical, chemical or physical change of the secondary refrigerant due to the mixed ammonia is monitored, so that the leak of ammonia can be detected immediately and surely. Monitoring of the ammonia leak above
The operation of the secondary refrigerant circulation pump is stopped during the secondary refrigerant supply from the evaporator to the load side device, and when the leakage or mixing of ammonia is detected, the operation of the secondary refrigerant circulation pump is stopped. Since the flow of the secondary refrigerant is stopped, the secondary refrigerant affected by the mixing of ammonia in the heat exchange section of the evaporator does not reach the load-side device. Among the reasons that ammonia is contraindicated to be mixed into the secondary refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment. This is because the copper pipes that are used are attacked by ammonia and the ammonia is toxic and causes eye and respiratory problems. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

According to the second aspect of the present invention, the secondary refrigerant circulation pump can be stopped more reliably by stopping the secondary refrigerant circulation pump, and the reliability of ensuring safety can be improved. There are various types of liquid pumps. When the pump stops, there is a type that almost completely shuts off between the suction port and the discharge port of the pump (for example, a piston pump). There is also a pump (for example, a centrifugal pump or the like) in which a connection between a suction port and a discharge port is made in a pump. Then, at the moment when the entrainment of the secondary refrigerant circulation pump driving motor is cut off when the mixing of ammonia is detected, the secondary refrigerant circulation pump also has a rotational inertia, and the secondary refrigerant also has flow energy. Therefore, even if the energization of the drive motor is stopped to stop the secondary refrigerant circulation pump, the circulation flow of the secondary refrigerant does not always stop immediately. Therefore, in the ammonia absorption chiller / heater having a configuration in which the circulating flow of the secondary refrigerant is continued for a while after the pump stops, when the circulating flow of the secondary refrigerant is shut off by the valve means by applying the second aspect, Maintenance of safety is further ensured. If the valve closing operation timing of the valve means precedes the stop of the secondary refrigerant circulation pump, there is a possibility that an abnormally high pressure may occur in a part of the secondary refrigerant circulation flow path. Is performed at the same time as or immediately after the stop of the secondary refrigerant circulation pump, so that there is no possibility of generating an abnormally high pressure.

According to the third aspect of the invention, not only is the flow of the secondary refrigerant in the load-side equipment shut off, but also the secondary refrigerant in the load-side equipment is discharged and removed from the load-side equipment. There is no danger of ammonia leaking from the load-side equipment into the room. In this case, not only the discharge valve is opened but also smooth discharge of the secondary refrigerant is not performed unless air at atmospheric pressure is introduced into the secondary refrigerant flow path in the load-side device. However, an open expansion valve is provided. If it is, it acts as an air inlet. Therefore, in the present invention, when the above-mentioned open type expansion valve is not provided, an air release valve for opening and communicating the secondary refrigerant circulation path to the atmosphere is provided so that the secondary refrigerant in the load-side device can be quickly supplied. So that it can be discharged to

According to the present invention, when ammonia leaks and mixes into the secondary refrigerant in the heat exchange section of the evaporator, the secondary refrigerant is electrically, chemically or physically mixed by the ammonia. Since the target change is monitored, the leak of ammonia can be immediately and reliably detected. In addition, since the mixing of ammonia in the open tank is monitored, the monitoring of ammonia is performed under the atmospheric pressure, and the monitoring can be performed by a non-pressure-resistant ammonia sensor. The above-described monitoring of the ammonia leakage is performed in an open tank provided in the middle of the secondary refrigerant supply from the evaporator to the load-side device, and when the leakage or mixing of ammonia is detected. Since the operation of the secondary refrigerant circulation pump is stopped and the flow of the secondary refrigerant in the load-side equipment is stopped, ammonia is mixed in the heat exchange section of the evaporator.
The next refrigerant does not reach the load side device. Among the reasons that ammonia is contraindicated to be mixed into the secondary refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment. This is because the copper pipes that are used are attacked by ammonia and the ammonia is toxic and causes eye and respiratory problems. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

According to the fifth aspect of the present invention, when ammonia leaks and mixes into the secondary refrigerant in the heat exchange section of the evaporator, the secondary refrigerant is electrically, chemically or physically mixed by the ammonia. Since changes are monitored, leaks are detected immediately and reliably. The above-described monitoring of the ammonia leakage is performed in an open tank provided in the middle of the secondary refrigerant supply from the evaporator to the load side device, and when the leakage and mixing of the ammonia are detected, While continuing the operation of the secondary refrigerant circulation pump, the secondary refrigerant flow path is switched, circulated to the open tank and the evaporator heat exchange section, and the load side device is bypassed.
The secondary refrigerant affected by the mixing of ammonia in the heat exchange section of the evaporator does not reach the load side equipment. The secondary refrigerant affected by the mixing of ammonia is circulated through the open tank, where the ammonia is diffused into the atmosphere and the ammonia concentration is reduced. Among the reasons that ammonia is contraindicated to be mixed into the secondary refrigerant, the largest one is that ammonia has severe corrosiveness to copper and constitutes a heat exchanger in the load side equipment. This is because the copper pipes that are used are attacked by ammonia and the ammonia is toxic and causes eye and respiratory problems. From this point of view, the practical value of preventing the ammonia from reaching the load-side equipment, which is an indoor unit, is enormous in practical use even in the event of an ammonia leak due to the application of the present invention. Contribute to the development of the ammonia absorption chiller / heater industry through ensuring the safety of water heaters.

According to the sixth aspect of the present invention, ammonia leaks into the secondary refrigerant in the evaporator heat exchange section (which may function as a condenser heat exchange section) of the ammonia absorption chiller or the ammonia absorption chiller / heater. If mixed, the ammonia sensor detects the leakage of ammonia, activates the automatic control device to stop the heating of the aqueous ammonia solution in the generator, and stops the circulation of the secondary refrigerant. 2 which was mixed
There is no fear that the next refrigerant reaches the load-side device. The load-side equipment is generally an indoor unit, and is affected by ammonia because its heat exchanger pipe is made of copper. For this reason,
It is extremely undesirable for the secondary refrigerant containing ammonia harmful to the human body to flow through the load-side device. Further, according to the device of the present invention, the danger that the ammonia-containing secondary refrigerant flows through the load-side device is completely prevented.

According to the device of the present invention, the effect of preventing harm in the device of the present invention is further ensured. In other words, in the device according to the sixth aspect, when ammonia is detected in the secondary refrigerant by the ammonia sensor, the operation of the secondary refrigerant circulation pump is stopped, and the ammonia-containing secondary refrigerant circulates to the load-side device. In the present invention, the above two items are defined.
In conjunction with the stoppage of the operation of the secondary refrigerant circulation pump, the flow of the secondary refrigerant in the secondary refrigerant circulation line is completely prevented by closing the shutoff valve. For this reason, the flow continuation due to the rotational inertia of the pump and the flow energy of the circulating flow is prevented, and the flow of the secondary refrigerant is immediately stopped.

According to the eighth aspect of the present invention, it is possible to more completely prevent the corrosion of the heat exchange pipe of the load-side device and the ammonia leakage from the load-side device. That is, when it is detected that ammonia leaks or mixes into the secondary refrigerant, the operation of the secondary refrigerant circulation pump is stopped or the circulation flow of the secondary refrigerant is stopped by a shut-off valve, so that ammonia leakage is caused. In this claim, the secondary refrigerant in the load-side device is discharged, and the entire amount of the secondary refrigerant in the secondary refrigerant flow path of the load-side device is replaced with air. The effect of harm prevention is more complete.

According to the ninth aspect of the present invention, when ammonia leaks and mixes into the secondary refrigerant in the evaporator heat exchange section, the secondary refrigerant first flows into the open tank because it circulates and flows. Here, mixing of ammonia is detected by the ammonia sensor. When the entry of ammonia is detected, the secondary refrigerant circulation pump is stopped by the operation of the automatic control device, and the circulation flow of the secondary refrigerant disappears before the ammonia-containing secondary refrigerant reaches the load-side device. At this time, since a substantial amount of the secondary refrigerant is stored in the open tank, the secondary refrigerant flows into the open tank, is diluted, the flow velocity is reduced, and slowly flows toward the open tank outlet. . For this reason, there is a large time margin for the ammonia sensor to detect the entry of ammonia and for the automatic control device to stop the secondary refrigerant circulation pump or stop the heating of the generator to suppress the generation of ammonia vapor. . In addition, a non-pressure-resistant ammonia sensor can be used, so an inexpensive sensor is sufficient.

According to the tenth aspect of the present invention, when ammonia is mixed in the secondary refrigerant, the ammonia sensor detects this, the automatic control device opens and closes the valve mechanism, and the secondary refrigerant is loaded. Side equipment is bypassed. That is, the load-side device is separated from the circulation flow of the secondary refrigerant, and the danger of ammonia leaking from the load-side device is completely prevented. The secondary refrigerant that bypasses the load-side device
Since it is made to circulate and flow between the evaporator heat exchange section and the open tank and makes the open tank contact the atmosphere to diffuse ammonia vapor, an increase in the ammonia concentration in the secondary refrigerant is suppressed.

According to the apparatus of claim 11, claim 1 is as follows.
In addition, the method according to the fifth aspect of the present invention can be carried out automatically, and its effect can be fully exhibited. In particular, it not only automatically activates the harm prevention device,
If necessary, the operating status of the harm prevention device can be displayed in real time, and maintenance advice information can be displayed.

[Brief description of the drawings]

FIG. 1 is a system diagram schematically illustrating a typical embodiment of an ammonia leakage harm prevention device according to the present invention.

FIG. 2 is a diagram in which a control system is added to a schematic piping system diagram showing three examples of an embodiment of a harm prevention device configured to carry out a harm prevention method of ammonia leakage according to the present invention, A) depicts the most basic example and (B) depicts 2
Drawing an embodiment in which a shut-off valve is provided in the circulation flow path of the secondary refrigerant,
(C) illustrates an embodiment in which means for discharging the secondary refrigerant out of the circulation system is provided.

FIG. 3 is a system diagram showing an embodiment different from that of FIG. 3 described above, in which the present invention is applied to an ammonia absorption chiller / heater provided with an open tank. An example of a control method is illustrated, and (B) illustrates an example of a method in which a secondary refrigerant discharge valve is provided.

FIG. 4 is a piping system diagram showing an embodiment different from the above, but the illustration of a control system is omitted due to space limitations, and FIG. 4 (A) shows a system provided with an open tank, a shutoff valve, and a bypass valve. (B) depicts a system further provided with an air release valve and a secondary refrigerant discharge valve.

FIG. 5 is a block diagram showing the configuration of the automatic control device shown in FIGS. 1 and 2 and input signals.

FIG. 6 is a schematic cross-sectional view showing an example of an absorption refrigerator of a type in which an aqueous ammonia solution is circulated in a closed circulation system, and is an explanatory view of a structure and functions in which arrows indicating flow directions are added to a schematic sectional view.

FIG. 7 is a table schematically depicting and comparing the expansion type of the refrigeration, the structure of the refrigerant part, and the structure of the heat exchange part with respect to a to c of the six types of style classification in the self-regulation of the refrigeration system.

FIG. 8 is a table schematically depicting and comparing the expansion form of the refrigerant, the structure of the refrigerant part, and the structure of the heat exchange part with respect to d to f of six style divisions in the self-regulation of the refrigeration system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Generator, 2 ... Burner as a heating means, 3 ... Condenser, 4 ... Evaporator, 4a ... Evaporator heat exchange part, 5 ... Absorber,
6 ... Solution pump, 7 ... Secondary refrigerant circulation pump, 8 ... Open tank, 9 ... Intermediate heat exchanger, 10 ... Load-side equipment, 11 ... Open expansion tank, 11 '... Closed expansion tank, 12
... Secondary refrigerant circulation line, 13 ... Ammonia sensor, 14 ...
Outgoing cutoff valve, 15 ... Return cutoff valve, 16 ... Secondary refrigerant discharge valve, 17 ... Secondary refrigerant treatment tank, 18 ... Bypass valve provided in parallel with load side equipment, 19 ... Atmosphere release valve, 20 ...
Air breather, 21 ... Automatic control device, 21a ... Detection signal and trigger signal input unit, 21b ... Storage unit, 21c
... Arithmetic operation unit, 21d ... comparison unit, 21e ... sensor self-diagnosis unit, 21f ... output unit, 21g ... display unit, 21h ... diagnosis mode, b ... arrow indicating the outward path of secondary refrigerant, b ... return path of secondary refrigerant Arrows shown, F: cooling fan for condenser.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Keiji Tachibana 3-9-2, Kanda Ogawamachi, Chiyoda-ku, Tokyo Inside Hitachi Cooling Systems Co., Ltd. (72) Inventor Kyoichi Sekiguchi Kyotodai Kida, Tsuchiura City, Ibaraki Prefecture 1-9-1 Hitachi Building System Co., Ltd. New Product Development Group (72) Inventor Joe Higo 3-9-2 Kanda Ogawamachi, Chiyoda-ku, Tokyo F-term (Ref.) 3L093 EE17 GG00 HH11 HH15 HH19 JJ06 KK01 LL05

Claims (11)

[Claims] 1. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and the condenser An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as “the ammonia vapor is generated in the generator. An ammonia solution that absorbs ammonia vapor in the absorber, and a solution pump that absorbs the ammonia vapor in the absorber and returns the concentrated ammonia aqueous solution to the generator for circulation. A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. In the ammonia absorption chiller / heater or the ammonia absorption chiller / heater obtained by adding a directional control valve for switching a flow path to the above-described components, heat is exchanged by the evaporator and is sent to the load side device. About the secondary refrigerant to be performed, desirably in the vicinity of the outlet of the evaporator heat exchange unit, “a change in the electrical properties of the secondary refrigerant that occurs when ammonia is mixed into the secondary refrigerant, or
Change of chemical or physical properties ", and monitor the presence or absence of ammonia contamination, stop the operation of the secondary refrigerant circulation pump, and stop the flow of the secondary refrigerant in the load side equipment, A method for preventing the danger of ammonia leakage, comprising stopping heating of the generator to suppress the generation of ammonia vapor and stopping the operation of the solution pump. 2. At the same time as the operation of the secondary refrigerant circulation pump is stopped or immediately after the operation is stopped, the flow of the secondary refrigerant in the circulation path is completely shut off by valve means to contain ammonia. 2. The method for preventing ammonia leakage according to claim 1, wherein the secondary refrigerant is not allowed to flow into the load-side equipment. 3. A secondary refrigerant discharge valve is provided at a lowest position or a position similar thereto in the secondary refrigerant circulation flow path, and at a highest position or in the secondary refrigerant circulation flow path. An open expansion tank or an air release valve is provided at a location corresponding to this, and when the operation of the secondary refrigerant circulation pump is stopped, air is released from the open expansion tank or the air release valve. And the discharge valve is opened to discharge the secondary refrigerant from the circulation flow path so that the secondary refrigerant does not remain at least in the load-side device. How to prevent the hazards of ammonia leaks described. 4. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as “the ammonia vapor is generated in the generator. An aqueous solution that absorbs ammonia vapor in the absorber, returns a concentrated aqueous ammonia solution to the generator, and circulates the solution; and A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. In the ammonia absorption chiller or the ammonia absorption chiller / heater obtained by adding a directional control valve for switching a flow path to the above-described components, an open tank provided in the middle of a circulation flow path of the secondary refrigerant is provided. "The change in the electrical properties or the change in the chemical or physical properties of the secondary refrigerant that occurs when ammonia is mixed into the secondary refrigerant"
Monitoring the presence or absence of ammonia, and when detecting ammonia contamination, stops the operation of the secondary refrigerant circulation pump, stops the flow of the secondary refrigerant in the load-side device, and stops the heating of the generator to release ammonia vapor. A method for preventing the danger of ammonia leakage, wherein the generation of water is suppressed and the operation of the solution pump is stopped. 5. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and the condenser An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as “the ammonia vapor is generated in the generator. An aqueous solution that absorbs ammonia vapor in the absorber, returns a concentrated aqueous ammonia solution to the generator, and circulates the solution; and A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. An ammonia absorption chiller or an ammonia absorption chiller / heater obtained by adding a directional control valve for switching a flow path to the above-mentioned components, wherein an open tank provided in the middle of a circulation flow path of the secondary refrigerant. Of the secondary refrigerant in the above, "a change in the electrical properties, or a change in the chemical or physical properties of the secondary refrigerant, which occurs when ammonia is mixed into the secondary refrigerant"
Monitoring the presence or absence of ammonia, when detecting ammonia contamination, a pipeline for introducing the secondary refrigerant in the open tank into the load-side equipment while continuing operation of the secondary refrigerant circulation pump, and
A pipe line for introducing the secondary refrigerant in the load-side device to the heat exchanger inlet of the evaporator is closed by closing a valve means, and the secondary refrigerant circulated by the secondary refrigerant circulation pump is sucked and discharged. Circulating the heat exchange section and the open tank of the evaporator and circulating, and circulating the "bypass valve connected in parallel with the load-side device" to prevent ammonia leakage. . 6. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and a condenser for cooling the ammonia vapor generated by the generator. An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as "the ammonia vapor was generated in the generator. An ammonia solution that absorbs ammonia vapor in the absorber, and a solution pump that absorbs the ammonia vapor in the absorber and returns the concentrated ammonia aqueous solution to the generator for circulation. A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. An ammonia absorption chiller / heater or an ammonia absorption chiller / heater comprising the above components and a directional control valve for switching a flow path, when ammonia is mixed in the secondary refrigerant,
An ammonia sensor that detects a change in the electrical properties of the secondary refrigerant, an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or an ammonia sensor that detects a change in the physical properties of the secondary refrigerant is configured. And an automatic control device that receives the output signal of the ammonia sensor and controls the secondary refrigerant circulation pump is provided. When a detection value of the ammonia sensor reaches a predetermined ammonia concentration, The automatic controller outputs a command signal for stopping the operation of the secondary refrigerant circulation pump, a command signal for stopping the operation of the means for heating the generator, and a command signal for stopping the operation of the solution pump. And the evaporator heat exchange section of the ammonia absorption chiller or the ammonia absorption chiller / heater and the load side equipment are connected to each other. In the following secondary refrigerant circulation pipeline, in the middle of the pipeline from the outlet of the evaporator heat exchange unit to the inlet of the load side device, preferably located near the evaporator heat exchange unit, An ammonia leak harm prevention device, wherein the ammonia sensor is connected. 7. A shut-off valve, which is electromagnetically opened and closed, is provided in the middle of a secondary refrigerant circulation line connecting the evaporator heat exchange part of the ammonia absorption chiller or the ammonia absorption chiller / heater to the load side equipment. When the detection value of the ammonia sensor reaches a predetermined ammonia concentration, the automatic control device outputs a command signal for closing the shut-off valve and outputs a command signal for closing the shut-off valve. 7. The ammonia leakage harm prevention device according to claim 6, wherein the forced circulation flow of the secondary refrigerant is eliminated. 8. An expansion tank is provided in the middle of a secondary refrigerant circulation line connecting the evaporator heat exchange section and the load-side device, and / or an electromagnetically operated air release valve is connected. An electromagnetically actuated secondary refrigerant discharge valve is provided at the lowest point of the secondary refrigerant circulation line, preferably at least at a position lower than the secondary refrigerant flow path of the load-side device. When the detected value of the ammonia sensor reaches a predetermined ammonia concentration, the automatic control device outputs a command signal for opening the secondary refrigerant discharge valve, and When the tank is not provided, a command signal for opening the atmosphere release valve is output together with the above-described command signal for opening the secondary refrigerant discharge valve, and the secondary refrigerant in the load-side device is removed by gravity. Natural spill out of the load side equipment 8. The ammonia leak harm prevention device according to claim 7, wherein the device is adapted to be closed. 9. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and a condenser for cooling the ammonia vapor generated by the generator. An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as “the ammonia vapor is generated in the generator. An aqueous solution that absorbs ammonia vapor in the absorber, returns a concentrated aqueous ammonia solution to the generator, and circulates the solution; and A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. An ammonia absorption chiller / heater or an ammonia absorption chiller / heater comprising the above components and a directional control valve for switching a flow path, when ammonia is mixed in the secondary refrigerant,
An ammonia sensor that detects a change in the electrical properties of the secondary refrigerant, an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or an ammonia sensor that detects a change in the physical properties of the secondary refrigerant is configured. And an automatic control device that receives the output signal of the ammonia sensor and controls the secondary refrigerant circulation pump is provided. When a detection value of the ammonia sensor reaches a predetermined ammonia concentration, The automatic controller outputs a command signal for stopping the operation of the secondary refrigerant circulation pump, a command signal for stopping the operation of the means for heating the generator, and a command signal for stopping the operation of the solution pump. And the evaporator heat exchange section of the ammonia absorption chiller or the ammonia absorption chiller / heater and the load side equipment are connected to each other. In the secondary refrigerant circulation line that continues, in the middle of the line from the outlet of the evaporator heat exchange unit to the inlet of the load-side device, "the inflow part of the secondary refrigerant is separated from the inflow part. An open tank that has an outflow portion and is not shielded from the atmosphere. The ammonia sensor detects that the secondary refrigerant in the open tank or the secondary refrigerant in a pipe near the open tank. An ammonia leakage harm prevention device characterized by detecting ammonia in a secondary refrigerant. 10. A generator for heating an aqueous ammonia solution to generate ammonia vapor, means for heating the generator, a condenser for cooling and liquefying the ammonia vapor generated by the generator, and a condenser for cooling the ammonia vapor generated by the generator. An evaporator that evaporates the ammonia liquid while causing heat exchange between the ammonia liquid and the secondary refrigerant generated in the above step, and an ammonia vapor that has been vaporized by the above evaporator is referred to as “the ammonia vapor is generated in the generator. An aqueous solution that absorbs ammonia vapor in the absorber, returns a concentrated aqueous ammonia solution to the generator, and circulates the solution; and A secondary refrigerant circulation pump that sucks, discharges, and circulates the secondary refrigerant that has undergone heat exchange in the vessel, and a load-side device that receives the secondary refrigerant in a circulating manner. An ammonia absorption chiller / water heater, or an ammonia absorption chiller / heater comprising the above components and a directional control valve for switching a flow path, wherein when ammonia is mixed into the secondary refrigerant,
An ammonia sensor that detects a change in the electrical properties of the secondary refrigerant, an ammonia sensor that detects a change in the chemical properties of the secondary refrigerant, or an ammonia sensor that detects a change in the physical properties of the secondary refrigerant is configured. And an automatic control device that receives a signal detected by the ammonia sensor is provided, and at least one of a secondary refrigerant inflow portion and a secondary refrigerant outflow portion of the load-side device is provided on one side, When the detection value of the ammonia sensor reaches a predetermined ammonia concentration, an electromagnetically operated shut-off valve that is operated to close by an automatic control device, and is connected in parallel with the load-side device to reach a predetermined ammonia concentration. An electromagnetically operated shut-off valve that is operated to open by the automatic control device, and Line connecting the evaporator heat exchange part of the steamer or the ammonia absorption chiller / heater to the load side equipment, from the outlet of the evaporator heat exchange part to the inlet of the load side equipment in the secondary refrigerant circulation pipeline In the middle of the "open tank having an inflow portion of the secondary refrigerant and an outflow portion separated from the inflow portion, and not shielded from the atmosphere" is provided, the ammonia sensor, A device for preventing danger of ammonia leakage, wherein the device detects ammonia in the secondary refrigerant in the open tank or in the secondary refrigerant in a pipeline near the open tank. 11. An automatic control device comprising: an input unit for inputting a detection signal of an ammonia sensor and a diagnosis start trigger signal; a storage unit for storing data; and a determination value based on a change in past data. An arithmetic unit that performs a comparison between a judgment value and a current value, a sensor self-diagnosis unit that compares stored data in a time series to judge sensor deterioration, and an output unit that outputs a signal to the outside. And the output unit outputs an ammonia leak alarm, an ammonia sensor deterioration alarm, a diagnostic mode, a chiller or chiller / warmer stop signal, a secondary refrigerant circulation pump stop signal, a shutoff valve close signal, and a discharge valve open signal. 11. The danger of ammonia leakage according to claim 6, having a function of outputting at least one of them. Prevention device.