JPH0557508B2 - - Google Patents

Description

[Detailed description of the invention] (a) Field of industrial application The present invention relates to an improvement of a cooling/heating switching type absorption refrigerator equipped with a device for exhausting hydrogen gas in non-condensable gas remaining inside the machine to the outside of the machine. .

(B) Prior Art In an absorption refrigerator, an absorption liquid (for example, a lithium bromide aqueous solution or aqueous ammonia) inside the machine reacts with metals that are constituent members of the equipment to generate hydrogen gas. It is generally known that this hydrogen gas remains in the machine as a non-condensable gas and becomes a factor in reducing the capacity of the absorption refrigerator.

Therefore, in absorption refrigerators, for example,
As explained in Japanese Patent Application No. 47-19970, a method has conventionally been employed in which hydrogen gas in a non-condensable gas tank is discharged into the atmosphere using a hydrogen gas exhaust device comprising a palladium tube and a heater.

However, in this conventional means, when the evaporator and absorber are operated at an internal pressure of about 6 to 8 mmHg, the hydrogen gas in the non-condensable gas tank can be discharged well. When the evaporator and absorber are operated at an internal pressure of about 130 mmHg, as is the case, the absorption liquid in the absorption refrigerator may enter the hydrogen gas exhaust system, and the palladium tubes of this equipment may become contaminated with the absorption liquid. There was a risk that the performance of the hydrogen gas exhaust system would deteriorate significantly.

(c) Purpose of the Invention The present invention prevents absorption liquid from entering a hydrogen gas exhaust system (hereinafter referred to as a dehydrogenation gas system) during heating operation, and prevents absorption liquid from entering the non-condensable gas during both heating and cooling operation. The object of the present invention is to provide a cooling/heating switching type absorption refrigerator equipped with a device that can efficiently discharge hydrogen gas.

(d) Structure of the Invention The present invention provides a gas extraction device for extracting non-condensable gas from an evaporator and/or absorber, and a gas storage chamber (non-condensable gas tank) for storing the extracted non-condensable gas.
In a cooling/heating switching absorption refrigerating machine (hereinafter referred to as this type of absorption refrigerating machine), a pressure equalizing pipe with a valve that is opened during heating operation is connected to the gas storage chamber and the evaporator and/or absorber. In addition, a dehydrogenation gas device consisting of a palladium hydrogen discharge tube and a heater for raising the temperature of this tube is connected to the gas storage chamber and the bleed chamber of the gas bleed device.

According to the present invention, during heating operation of this type of absorption refrigerator, the valve of the pressure equalization pipe is opened and the pressure in the gas storage chamber, evaporator, and absorber becomes approximately the same, so that the evaporator is lower than during cooling operation. Even if the absorber is operated with a high internal pressure, the absorbed liquid in the absorber can be prevented from entering the dehydrogenation gas apparatus via the gas storage chamber. In addition, in this type of absorption refrigerator according to the present invention, hydrogen gas in the gas storage chamber or the gas storage chamber and the bleed chamber can be exhausted during cooling operation by the dehydrogenation gas device connected to these chambers; Since the hydrogen gas that sometimes collects in the bleed chamber of the gas bleed device can be exhausted by the dehydrogen gas device connected to the bleed chamber, hydrogen gas can be efficiently discharged during both cooling and heating operations.

(e) Embodiment The drawing is a schematic structural explanatory diagram showing an embodiment of this type of absorption refrigerator according to the present invention, in which 1 is a high-temperature generator, 2 is a generated condensation machine consisting of a low-temperature generator 3 and a condenser 4. 5 is an evaporator-absorber consisting of an evaporator 6 and an absorber 7; 8 and 9 are high-temperature and low-temperature solution heat exchangers; 10 and 11 are pumps for refrigerant liquid and absorption liquid, respectively; flowing pipe 1
2, 13 Pipe 14 for refrigerant liquid to flow down, pipes 15, 16 for refrigerant liquid to flow back, pipes 17, 1 for absorption liquid to be sent
8. By the pipes 19, 20 through which the absorption liquid flows, the pipes 21, 22 through which the absorption liquid flows, the pipe 23 through which refrigerant vapor flows with a cooling/heating switching valve _V1 , and the pipe 24 through which the absorption liquid flows downward with a cooling/heating switching valve _V2 . The refrigerant (water) is connected to the conventional cooling/heating switching type absorption refrigerator.
and a circulation path for an absorption liquid (lithium bromide aqueous solution). 25 is the combustion heating chamber of the high temperature generator 1, 26, 26... are pipes through which combustion gas flows, 27 is the heater of the low temperature generator 3, 28 is the heat exchanger of the evaporator 6, and 29, 30 are the condensers 4, respectively. , the cooler of the absorber 7; 31 and 32 are the refrigerant reservoirs of the condenser 4 and the evaporator 6, respectively; 33 and 34 are the absorption fluid reservoirs of the low temperature generator 3 and the absorber 7, respectively; 35, 36, and 37
is an eliminator, 38 and 39 are water flowing pipes that connect the heat exchange unit (not shown) on the air conditioning side and the heat exchanger 28, and 40, 41, and 42 are connected in series with the coolers 30 and 29. This is a pipe through which cooling water flows.

In the cooling/heating switching type absorption refrigerator configured as described above (hereinafter referred to as this machine), during cooling, the cooling/heating switching valve V ₁ , an absorption refrigeration cycle is formed by operating with _V2 closed,
The latent heat of vaporization of the refrigerant liquid dispersed in the heat exchanger 28 lowers the temperature of the water in the heat exchanger 28 and sends it to the heat exchange unit on the air conditioning side. In addition, during cooling, the cooling/heating switching valves V ₁ and V ₂ are opened, the pump 10 is stopped, and the flow of cooling water to the coolers 30 and 29 is cut off. The refrigerant vapor generated in the generator 1 is caused to flow into the evaporator-absorber 5 via the pipe 23, and the heat released when the refrigerant vapor that has flowed into the evaporator-absorber 5 is condensed in the heat exchanger 28 causes the heat exchanger 28 to be heated. The water is heated and sent to the heat exchange unit on the air conditioning side. The refrigerant condensed in the heat exchanger 28 fell into the refrigerant reservoir 32, further overflowed from the refrigerant reservoir 32 to the absorption fluid reservoir 34, and flowed from the high temperature generator 1 into the absorption fluid reservoir 34 via the pipe 24. The pump 11 along with the absorption liquid passes through the pipes 17 and 18 to the high temperature generator 1.
be returned to.

Reference numeral 43 denotes a bleed chamber connected to the gas phase portion of the evaporative absorber 5 through a bleed pipe a, and this bleed chamber is equipped with an absorption liquid dispersion device 44. Reference numeral 45 denotes a temperature riser that lowers the temperature of the absorption liquid in the vessel, and this temperature riser has a built-in heating coil 46 through which water flows. In addition,
Water side pipes 38' and 39' are connected to the heating coil. 47 is a gas storage chamber for storing non-condensable gas. Reference numeral 48 denotes a container in which the absorption liquid sent by the pump 11 from the absorption liquid reservoir 34 via the pipe b overflows through the overflow pipe c, while keeping the liquid level in the container almost constant. A substantially constant amount of absorption liquid is allowed to flow down from the temperature dropper 45 to the cooling device 45. The bleed chamber 43, the temperature reducer 45, the gas storage chamber 47, the container 48, and the absorber 7 include pipes b, d, e, f, g, a pipe h having a U-shaped part, a bleed pipe a, and a U-shaped part. A non-condensable gas bleed system similar to a conventional gas bleed system is constructed by connecting the two through an overflow pipe c having a .

i is a pressure equalizing pipe that connects the gas storage chamber 47 and the evaporative absorber 5 and has a valve V ₃ in the middle that is opened only during heating operation of the machine.

Reference numeral 49 denotes a dehydrogenation gas device, in which an electric heater or other heater 50 is arranged in the center, and gas collection chambers 51, 52 are arranged on both sides. 52 each has a hydrogen release tube 5 made of palladium or its alloy.
3 and 54 are inserted so as to sandwich the heater 50 therebetween. It goes without saying that the walls of the gas collection chambers 51 and 52 and the outer walls of the hydrogen discharge tubes 53 and 54 are airtightly connected by means such as welding or brazing. Then, the gas collection chamber 5 of the dehydrogenation gas device 49
1 and the gas storage chamber 47 are connected by a gas conduit j, and the gas collection chamber 52 of the dehydrogenation gas device 49
and the gas phase part of the bleed chamber 43 are connected by a gas conduit k.

Next, an example of the operation of the dehydrogenation gas device will be described together with the gas extraction operation during cooling operation and heating operation of the present machine equipped with the gas extraction device and dehydrogenation gas device configured as described above.

During cooling operation, the absorption liquid (dilute absorption liquid) whose concentration has been reduced by absorbing refrigerant while being lowered in temperature by the cooling water in the absorber 7 becomes about 35°C, for example, and accumulates in the absorption liquid reservoir 34, and is pumped by the pump 11. It is then sent to the container 48 via pipe b. The dilute absorption liquid that has flowed into the container 48 flows down to the temperature reducer 45 via the pipe d and is returned to the absorption liquid reservoir 34 via the overflow pipe c.
The dilute absorption liquid that has flowed into the temperature lowering device 45 has a temperature of about 20° C. due to the water flowing into the temperature lowering coil 46 at about 12° C., for example.
The temperature is lowered to ℃, and the sparge 4 in the bleed chamber 43 is passed through the pipe e.
Flows down to 4. Then, a dilute absorption liquid at about 20° C. is sprayed into the bleed chamber 43. Note that the water that has undergone heat exchange with the dilute absorption liquid is heated to, for example, about 15° C. and is returned to the pipe 39. The temperature of the absorption liquid sprayed into the bleed chamber 43 is approximately 15°C lower than the temperature of the diluted absorption liquid in the absorption liquid reservoir 34, and its saturated vapor pressure is also lower, so the internal pressure of the bleed chamber 43 is lower than the internal pressure of the evaporator absorber 5. kept low. Incidentally, the internal pressure of the bleed chamber 43 is about 3 mmHg, and the internal pressure of the evaporator absorber 5 is about 6 mmHg. Therefore, the evaporative absorber 5
The non-condensable gas containing hydrogen gas inside is extracted into the bleed chamber 43 via the bleed pipe a along with the refrigerant vapor. The extracted refrigerant vapor is absorbed by the dilute absorption liquid spread in the bleed chamber 43, and the non-condensable gas is absorbed into the pipe f along with the absorption liquid whose concentration has further decreased by absorbing the refrigerant (hereinafter referred to as dilute solution). It reaches pipe g while flowing down. The non-condensable gas that has reached the pipe g floats up the pipe g, reaches the gas storage chamber 47, and is stored in this gas storage chamber. On the other hand, the dilute solution is passed through the pipe h to the absorption liquid reservoir 34.
Return to

Then, the non-condensable gas in the gas storage chamber 47 is transferred to the gas collection chamber 51 of the dehydrogenation gas device 49 via the gas conduit j.
The hydrogen gas in the non-condensable gas that has reached this gas collection chamber is released into the atmosphere via the hydrogen release pipe 53. Here, the principle of releasing hydrogen gas in the dehydrogenation gas device 49 [this principle is well known]. ]
Explain briefly. When the hydrogen release tube 53 made of palladium or its alloy is heated to a high temperature by activating the heater 50 (for example, by energizing an electric heater), the hydrogen gas contained in the non-condensable gas is converted to atomic hydrogen on the surface of the tube 53. dissociates into The atomic radius of atomic hydrogen is very small compared to the atomic radius of other noncondensable gases. A hydrogen atom is made up of one proton and one electron, and the radius of the proton is 1.5×
10 ^-5 Å, and hydrogen is slightly larger. On the other hand, for example, the lattice constant of palladium is
3.88 Å, hydrogen permeates the palladium wall by intralattice diffusion. Furthermore, other non-condensable gases and the atmosphere do not dissociate on the palladium wall, so they cannot pass through the palladium wall. Therefore, the hydrogen gas in the gas collection chamber 51 is released into the atmosphere through the hydrogen release pipe 53.

Furthermore, hydrogen gas in the bleed chamber 43 is also released into the atmosphere through the hydrogen release pipe 54 based on the same principle.

In addition, the on-off valve connected to the gas storage chamber 47
A pipe m with a V ₄ is for appropriately discharging non-condensable gases other than hydrogen gas, and a vacuum pump (not shown) is installed in this pipe m. However, since this machine is manufactured to ensure sufficient airtightness at the welded parts of the machine and the connection parts with the pumps 10 and 11, the non-condensable gas normally stored in the gas storage chamber 47 Most of the gas becomes hydrogen gas. Therefore, in this machine, there is little need to discharge non-condensable gas using a vacuum pump, and by operating the dehydrogenation gas device 49, the pressure inside the gas storage chamber 47 can be reduced during cooling operation or when the operation is stopped. The saturated vapor pressure of the absorption liquid in Incidentally, the internal pressure of the gas storage chamber 47 is normally maintained at about 6 to 10 mmHg.

During heating operation, for example, when the heat exchanger 28 is operated so that the water inlet and outlet temperatures are approximately 55°C and 50°C, the internal pressure of the evaporator absorber 5 is approximately 130 mmHg, and the temperature of the absorption liquid in the absorption liquid reservoir 34 is approximately The temperature will be 85℃. In this case, the temperature of the absorption liquid that has flowed into the temperature lowering device 45 is lowered to, for example, approximately 70° C. by the water that flows into the temperature lowering coil 46 at approximately 50° C. During heating operation, the pressure inside the bleed chamber 43 is lower (approximately 70 mmHg) than in any of the other components, and the non-condensable gas in the evaporator absorber 5 is extracted and collected in the bleed chamber 43.

By the way, during heating operation, a dilute solution with a higher temperature (e.g. 70°C) flows into pipe g than during cooling operation,
Moreover, the internal pressure of the evaporator-absorber 5 is about 120 mmHg higher than that during cooling operation. For this reason, in the case of the conventional device that does not have the pressure equalizing tube i, there is a large risk that the dilute solution in the tube g will rise to the gas storage chamber 47, and the high temperature dilute solution is kept at a low pressure of about 6 to 10 mmHg. It violently boils and flashes in the gas phase portion of the pipe g or in the gas storage chamber 47, which had been hanging down. Then, the small droplets of the dilute solution that flash and scatter enter the gas collection chamber 51 via the gas conduit j, and enter the hydrogen release pipe 5.
It contaminates 3. Further, during the heating operation, the internal pressure of the high temperature generator 1 is lower than that during the cooling operation, and the absorption liquid level in the absorption liquid reservoir 34 is lower than that during the cooling operation. Therefore, in the case of a small conventional device, when the gas storage chamber 47 begins to be filled with absorption liquid, the level of the absorption liquid in the absorption liquid reservoir 34 drops extremely, causing cavitation of the pump 11.

On the other hand, in this machine, the valve _V3 of the pressure equalizing pipe i is opened during heating operation to make the internal pressure of the gas storage chamber 47 the same as the internal pressure of the evaporator absorber 5, thereby preventing the dilute solution from rising and flashing. Therefore, in this machine, contamination of the hydrogen discharge pipe 53 and cavitation of the pump 11 can be reliably prevented. In addition,
In this machine, during heating operation, hydrogen gas is hardly stored in the gas storage chamber 47, so although hydrogen gas is not sufficiently exhausted through the hydrogen discharge pipe 53, hydrogen gas collects in the bleed chamber 43. flows into the gas collection chamber 52 via the gas conduit k and is exhausted through the hydrogen discharge pipe 54. Therefore, hydrogen gas can be discharged to the outside of the machine even during heating operation.

In addition, as shown by the two-dot chain line in the figure, dehydrogenation gas devices 49' and 49'' are provided, and during heating operation, only the dehydrogenation gas device 49'' is operated and the bleed chamber 4
During cooling operation, the hydrogen gas collected in the dehydrogenation gas device 49' or both devices 4 is released.
9', 49'' may be operated to release hydrogen gas.In addition, in a cooling/heating switching type absorption refrigerator, the absorption in the high temperature generator 1 is normally lower during cooling operation than during heating operation. Since it is necessary to raise the temperature of the liquid, more hydrogen gas is generated. Therefore, it is preferable to operate both devices 49' and 49'' during cooling operation.

Although the embodiment shown in the drawings describes the case where the present invention is applied to a double-effect absorption refrigerator, it goes without saying that the present invention can be applied to a single-effect absorption refrigerator. It is also possible to apply the present invention to a cooling/heating switching type absorption refrigerator that switches to a system.

(F) Effects of the Invention As described above, in this type of absorption refrigerator according to the present invention, during heating operation, the hydrogen gas that collects in the bleed chamber with the lowest pressure is released into the atmosphere by the dehydrogenation gas device, and Since the hydrogen gas in the gas storage chamber or the gas storage chamber and the bleed chamber is released during cooling operation, the hydrogen gas in the non-condensable gas can be efficiently discharged to the outside of the machine during both cooling and heating operations.

Furthermore, in this type of absorption refrigerator according to the present invention, the gas storage chamber and the evaporative absorber are pressure-equalized during heating operation, so that flashing of the absorption liquid in or near the gas storage chamber can be prevented. is possible,
It is possible to reliably prevent the dehydrogenation gas device connected to the gas storage chamber from being contaminated by the absorption liquid, and to maintain good performance of the dehydrogenation gas device.

[Brief explanation of the drawing]

The drawing is a schematic structural diagram showing an embodiment of this type of absorption refrigerator according to the present invention. 1... High temperature generator, 2... Generation condenser, 3...
Low temperature generator, 4... Condenser, 5... Evaporative absorber,
6...evaporator, 7...absorber, 8,9...high temperature,
Low temperature solution heat exchanger, 10, 11...pump, 28
...Heat exchanger, 29,30...Cooler, 34...
Absorption liquid reservoir, 38, 39...tube, 40, 41, 4
2...Pipe, 43...Bleed chamber, 45...Cooler, 4
7... Gas storage chamber, 48... Container, 49, 49',
49″... Dehydrogenation gas device, 51, 52... Gas collection chamber, 53, 54... Hydrogen release pipe, a... Bleed pipe, b... Pipe, c... Overflow pipe, d,
e, f, g, h... tube, i... pressure equalizing tube, m...
Pipe, V ₁ , V ₂ ... Cooling/heating switching valve, V ₃ ... Valve, V ₄ ...
Open/close valve.

Claims (1)

[Claims] 1 Palladium that is equipped with a gas extraction device that extracts non-condensable gas from the evaporator and/or absorber and a gas storage chamber that stores the extracted non-condensable gas, and that permeates and releases hydrogen in the non-condensable gas. A dehydrogenation gas device consisting of a hydrogen discharge pipe made of a hydrogen discharge pipe or a heater for raising the temperature of this pipe is connected to the gas storage chamber and the bleed chamber of the gas bleed device by a gas pipe, and a valve that is opened during heating operation. A cooling/heating switching type absorption refrigerator characterized in that a pressure equalizing pipe having a pressure equalizing pipe is connected to a gas storage chamber and an evaporator and/or an absorber.