JP4002507B2 - NH3 heat pump - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat pump that uses ammonia gas as a refrigerant, and relates to a system configuration that minimizes the amount of ammonia gas that leaks when the ammonia gas leaks, and to an NH ₃ heat pump that includes a means for eliminating leaked ammonia gas.
[0002]
[Prior art]
Recently, from the viewpoint of protecting the global environment and preventing global warming, refrigerators and air conditioning heat pumps that use natural refrigerants such as ammonia gas that have both zero ozone depletion potential and global warming potential are widely used. Has been.
However, ammonia gas has the following advantages and disadvantages in addition to the fact that there is no concern about environmental pollution. That is,
Advantages include low cost, high COP, good thermal conductivity, high cooling efficiency, and easy detection at the time of leakage.
Disadvantages include toxicity, flammability (but flame retardant), corrosivity, and the inability to use copper-based materials.
In other words, when ammonia gas leaks, it is necessary to keep the amount of air leaked low from the viewpoint of safety and health due to the above-mentioned drawbacks, and to keep the atmosphere air at the lower limit of ignition.
[0003]
With regard to the recovery of the refrigerant gas and the like, proposals relating to “refrigerant gas control device of heat pump system” have been made. (For example, refer to Patent Document 1.)
In the heat pump system using NH ₃ and other water-soluble refrigerants, the above proposal collects the refrigerant gas leaked into the machine room in the state of gas to prevent malfunction of equipment, occurrence of rust and corrosion, and operation It is intended to improve efficiency and reduce operating costs.
[0004]
As shown in FIG. 3, the control apparatus includes an ice storage room that includes a machine room 56 including a compressor 53, a condenser 54, and an expansion valve 55, and an evaporator 52 that sends out high-pressure refrigerant from the machine room. 57. A gas suction line is formed which communicates from the gas phase portion of the machine chamber 56 and the ice heat storage chamber 57 to the liquid phase portion of the ice heat storage chamber to form an evaporator, and the machine chamber side gas suction pipe 58 and the ice heat storage chamber side are provided. A gas suction line 59 is provided, and the leakage of NH ₃ refrigerant gas in the machine room is detected by the detection pipe 60 and input to the control device 61. The air flow distributor 62 is controlled by the control device, and the NH in the machine room 56 is controlled. According to the amount of leakage of the _three gases, the gas suction ratio from the machine chamber 56 and the ice heat storage chamber 57 is controlled to be ejected from the ejection pipe 64 through the blower 63, and the leaked gas is made into the liquid phase of the ice heat storage chamber 57. It is intended to capture.
[0005]
Further, as an improvement plan of the above proposal, for example, a proposal related to an “evaporation condensation type ammonia refrigeration unit” has been proposed. (For example, refer to Patent Document 2.)
In this proposal, ammonia gas is recovered using the high solubility of ammonia gas in water, and the water for dissolution is used to improve the COP of the refrigeration unit by using the cooling water of the evaporative condenser. The purpose is to provide a refrigeration unit capable of collecting the leaked gas that also contributes.
[0006]
As shown in FIG. 4, the refrigeration unit is formed as an integrated package of an upper storage chamber 72 a and a lower storage chamber 73 a, and the upper and lower boundaries are hermetically sealed. A push-in fan 71 is provided on the lower left side of the upper storage chamber 72a, a recess is provided in the lower portion of the push-in fan to form a cold water tank 74, and cold water is assembled from the cold water tank and sprayed to the condenser 72 from the coolant spray nozzle 72b. Thus, an evaporative condenser is formed.
The upper storage chamber 72a is provided with a condenser 72 for condensing ammonia gas, a cooling water spray nozzle 72b, and the pushing fan 71.
The lower storage chamber 73a is provided with a compressor 70 for compressing ammonia gas, an oil separator 70a and related accessories to form a machine room, and a dynamic manufacturing device 75 for forming a load outside the machine. is there.
There is provided a guide channel 76 that vertically passes through the airtight boundary between the suction side of the push-in fan 71 and the lower storage chamber 73a and collects ambient air in the lower storage chamber 73a, which is a machine room, The atmospheric air in the lower storage chamber is sucked in as shown by a one-dot chain line, and then pushed into the condenser 72 as shown by a two-dot chain line through the pushing fan 71, and the atmosphere in the lower storage chamber which is the machine room When there is leakage of ammonia gas in the air, the sprayed cooling water of the cooling water spray nozzle 72b is collected and stored in the cold water tank 74 for detoxification.
[0007]
Moreover, in the refrigerant | coolant collection | recovery apparatus coped with when the refrigerant | coolant leakage occurs in the said refrigerating cycle, there exists a proposal regarding the prevention means of the backflow to the refrigerating cycle of the refrigerant | coolant once collect | recovered, for example. (For example, refer to Patent Document 3.)
The above proposal suggests that if an adsorbent or absorbent is used to recover hydrocarbons or ammonia leaked from the refrigeration cycle, the temperature of the recovered refrigerant will rise due to the pressure drop in the refrigeration cycle and the adsorbent heat generation in the adsorbent filling section. However, this problem was made in order to solve this problem. Thereafter, the collection container is hermetically shut off.
[0008]
Moreover, as an ammonia removal system in the refrigeration cycle, for example, there are proposals described below. (For example, refer to Patent Document 4.)
The above proposal introduces ammonia gas leaked from the refrigerator unit into a closed space such as a scrubber before release into the atmosphere, and reacts it with carbon dioxide and water to produce ammonium carbonate or ammonium hydrogen carbonate, etc. This salt is produced and detoxified.
[0009]
[Patent Document 1]
JP-A-8-136096 [Patent Document 2]
JP 11-30460 A [Patent Document 3]
JP 2001-174108 A [Patent Document 4]
JP 2001-347127 A
[Problems to be solved by the invention]
By the way, as seen in the prior art, the conventional ammonia gas leakage countermeasures are limited only to the removal of the leaked ammonia gas, and any countermeasures other than stopping the compressor are taken to stop the leakage. I didn't come. An object of the present invention is to provide an NH ₃ heat pump that not only removes the leaked ammonia gas, but also actively separates the leaked part and systematically separates the liquid receiving part having a large amount of refrigerant. .
[0011]
[Means for Solving the Problems]
Therefore, the NH ₃ heat pump of the present invention is
In a heat pump comprising a compressor, a condenser, an evaporator, a receiver, a pressure reducing device, and related accessories, and using ammonia gas as a refrigerant and having a means for eliminating leaked ammonia gas,
A return refrigerant gas introduction path from an air heat exchanger that operates for the evaporator and a return refrigerant gas introduction path from a water heat exchanger that also operates for the evaporator are connected to the suction side of the compressor. Each is provided with a shut-off valve, and either the air heat exchanger or the water heat exchanger where ammonia gas has leaked is separated from the heat pump cycle system,
A configuration in which a three-way valve is provided on the discharge side of the compressor and the compressed gas is sent out to the heat exchanger side where the ammonia gas does not leak is configured to minimize the amount of generated leakage.
[0012]
In the present invention described above, an air heat exchanger and a water heat exchanger, which are concerned about leakage of ammonia gas, are provided with a shut-off valve from the compressor suction side in order to separate the heat exchanger in which a leakage accident has occurred from the heat pump cycle system. In addition to disconnecting, the discharge side of the compressor is switched and sent to the heat exchanger that is not disconnected, and the leakage heat exchanger is separated and disconnected from the cycle system to minimize the amount of ammonia leakage. is there.
[0013]
For example, as shown in FIG. 2A, a compressor 80, an air heat exchanger 81, a water heat exchanger 82, a liquid receiver 83, a gas side four-way valve 84, a liquid side four-way valve 85, an expansion valve 86, etc. In the conventional air heat source heat pump including the refrigerant, the refrigerant vapor evaporated in the air heat exchanger 81 is routed to the intake side of the compressor 80 by the gas side four-way valve 84 during the heating operation in which hot water is taken out from the water heat exchanger 82. Forming.
In the above circuit configuration, when an ammonia gas leakage accident occurs in the air heat exchanger 81, the expansion valve 86 immediately shifts to a disconnected state, but on the suction side of the air heat exchanger 81 and the compressor 80, Since the circuit to be connected is not provided with a shutoff valve, the air heat exchanger 81 in which a leakage accident has occurred cannot be separated from the cycle system and excluded. Therefore, ammonia gas leakage continues and damage increases. In the present invention, a shut-off valve is provided in the introduction path to the compressor via the gas side four-way valve, and the air heat exchanger that has caused the leakage accident is separated and separated.
[0014]
As shown in FIG. 2B, as in FIG. 2A, the compressor 80, the air heat exchanger 81, the water heat exchanger 82, the liquid receiver 83, the gas side four-way valve 84, the liquid In a conventional air heat source heat pump including a side four-way valve 85, an expansion valve 86, etc., the refrigerant vapor evaporated in the water heat exchanger 82 is compressed by the gas side four-way valve 84 during the cooling operation in which the cold water is taken out from the water heat exchanger 82. An introduction path to the suction side of the machine 80 is formed.
In the above circuit configuration, when an ammonia gas leakage accident occurs in the water heat exchanger 82, the expansion valve 86 immediately shifts to a disconnected state, but on the suction side of the water heat exchanger 82 and the compressor 80, Since the circuit to be connected is not provided with a shut-off valve, the water heat exchanger 82 in which a leakage accident has occurred cannot be separated from the cycle system and excluded. As a result, leakage continues. In the present invention, a shut-off valve is provided in the introduction path to the compressor via the gas side four-way valve, and the water heat exchanger that has caused the leakage accident is separated and separated.
[0015]
In the NH ₃ heat pump of the present invention,
The liquid receiver is provided with a shut-off valve at the inlet side inlet from the air heat exchanger and the water heat exchanger to the liquid receiver, and makes the liquid receiver independent of the heat pump cycle system when ammonia gas leaks Is preferred.
[0016]
In the above invention, when ammonia gas leaks, a check valve or a shut-off valve is provided at the inlet of a liquid receiver that holds most of the refrigerant in the refrigerant system, and is separated from the cycle system to be independent.
[0017]
And also in the NH ₃ heat pump of the present invention,
The abatement means is preferably configured by water spray abatement.
[0018]
The invention described above describes the means for eliminating leaked gas, and is preferably provided with the necessary water spray removing means.
[0019]
And also in the NH ₃ heat pump of the present invention,
The detoxification means preferably has a detoxification water tank and is configured to inject leaked gas or store dissolved ammonia water.
[0020]
In the invention described above, the abatement means is preferably provided with a detoxification water tank, and leakage gas is blown into the water tank or ammonia gas-dissolved water is stored.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the form of the Example of this invention is demonstrated with the example of illustration. However, unless otherwise specified, the dimensions, shapes, relative positions, and the like of the components described in this embodiment are merely illustrative examples, and are not intended to limit the scope of the present invention. Absent. The details of the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an NH ₃ heat pump according to the present invention.
[0022]
As shown in FIG. 1, the NH ₃ heat pump of the present invention has a structure formed by an integrated package composed of an upper storage chamber 20b and a lower storage chamber 20a.
The lower storage chamber 20a has a structure in which a compressor 30, a water heat exchanger 32, a liquid receiver 33, an expansion valve 36 and related accessories are built in to form a machine room,
The upper storage chamber 20b has a structure in which an air heat exchanger 31 provided with a suction fan 31a and an outside air intake port 20d are provided.
A boundary 20c made of an airtight member is provided between the upper storage chamber 20b and the lower storage chamber 20a, and a penetration portion that leads to the upper storage chamber is provided in the boundary 20c, and the electric shutter 15a and the ventilation are provided in the penetration portion. A fan 15 is provided to guide outside air taken in through the electric shutter 16 of the lower storage chamber 20a to the upper storage chamber 20b along the arrow A, and is sucked together with outside air B taken in from the outside air intake port 20d in the upper storage chamber 20b. It is configured to ventilate through the fan 31a.
[0023]
The ammonia gas leak detectors 14a and 14b are provided in the upper spaces of the upper storage chamber 20b and the lower storage chamber 20a, respectively, and are configured to detect gas leakage in each space, and upstream of the suction fan 31a and A non-illustrated water spray nozzle (not shown) is provided at the suction port of the ventilation fan 15 to dissolve and remove the leaked ammonia gas by water spray. Each is provided and collected.
[0024]
The present invention is provided with two-way valves 10a and 10b in place of the above-described conventional four-way valve switching circuit, in addition to the above-described ammonia gas detoxifying structure, and is provided with an air heat exchanger 31 or a water heat exchanger 32. The introduction of ammonia gas returning to the suction side of the compressor 30 is shut off, and the air heat exchanger 31 or the water heat exchanger 32 is connected in parallel to the two-way valve from the discharge side of the compressor 30 via the check valve 13. It is set as the structure which provides the three-way valve 11 sent out to either of these.
Further, the check valve 12 is provided on the refrigerant liquid introduction side of the liquid receiver 33, and the liquid receiver that stores a large amount of refrigerant liquid is separated from the heat pump cycle system and separated.
[0025]
That is, when ammonia gas leaks during the heating operation in which hot water is taken out from the water heat exchanger 32, the air heat exchanger 31 is moved to the water heat exchanger 32 side of the two-way valve 10a, the expansion valve 36, and the three-way valve 11. The liquid receiver 33 is separated from the circuit system by the check valve 12, the liquid supply electromagnetic valve, and the expansion valve 36.
[0026]
When ammonia gas leaks during cooling operation in which cold water is taken out from the water heat exchanger 32, the water heat exchanger 32 is switched to the air heat exchanger 31 side of the two-way valve 10b, the expansion valve 36, and the three-way valve 11. Thus, the liquid receiver 33 is separated from the heat pump cycle system by the check valve 12, the liquid supply electromagnetic valve, and the expansion valve 36.
[0027]
In addition, when the ammonia gas detector 14a provided in the upper storage chamber 20b detects leakage of ammonia gas, the ammonia gas detector provided in the lower storage chamber is activated by operating the water spray abatement device provided in the air heat exchanger. When the gas leakage in the lower storage chamber 20a is detected by 14b, the electric shutters 15a and 16 are closed and the water spray abatement device is operated.
When the occurrence of leakage is detected, the compressor 30 immediately stops operation.
[0028]
【The invention's effect】
With the above configuration, the present invention has the following effects.
In addition to detoxifying the leaked ammonia gas, it is possible to actively separate the leaked part and make the liquid receiving part having a large amount of refrigerant independent from the heat pump system, thereby minimizing the leakage of ammonia gas.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of an NH ₃ heat pump according to the present invention.
2A is a diagram showing a circuit configuration during heating operation of a conventional air heat source heat pump, and FIG. 2B is a diagram showing a circuit configuration during cooling operation of the air heat source heat pump shown in FIG.
FIG. 3 is a diagram showing a configuration of a refrigerant gas control device of a conventional heat pump system.
FIG. 4 is a diagram showing a schematic configuration of a conventional evaporative condensation type ammonia refrigeration unit.
[Explanation of symbols]
10a, 10b Two-way valve 11 Three-way valve 12, 13 Check valve 14a, 14b Ammonia gas leak detector 15 Ventilation fan 15a, 16 Electric shutter 20a Lower storage chamber 20b Upper storage chamber 20c Boundary 20d Outside air intake

Claims (3)

In a heat pump comprising a compressor, a condenser, an evaporator, a receiver, a pressure reducing device, and related accessories, and using ammonia gas as a refrigerant and having a means for eliminating leaked ammonia gas,
A return refrigerant gas introduction path from an air heat exchanger that operates for the evaporator and a return refrigerant gas introduction path from a water heat exchanger that also operates for the evaporator are connected to the suction side of the compressor. Each is provided with a shut-off valve, and is configured to separate either the air heat exchanger or the water heat exchanger where ammonia gas leaked from the heat pump cycle system,
The NH is characterized in that a three-way valve is provided on the discharge side of the compressor, and the compressed gas is sent to the heat exchanger side where the ammonia gas does not leak, so that the amount of generated leakage is minimized. ₃ heat pump. The liquid receiver is provided with a shut-off valve at the inlet side inlet from the air heat exchanger and the water heat exchanger to the liquid receiver, and makes the liquid receiver independent of the heat pump cycle system when ammonia gas leaks The NH ₃ heat pump according to claim 1, wherein The NH ₃ heat pump according to claim 1, wherein the abatement means is constituted by water spray abatement.

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