JPH063333B2 - Non-condensing gas removal device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a machine such as an absorption refrigerating machine or an absorption heat pump whose atmospheric pressure is kept at atmospheric pressure or less, and particularly to a machine corrosion caused by a solution in the machine. The present invention relates to an improvement of a non-condensable gas removing device (hereinafter referred to as this type of device) applied to a machine that generates hydrogen gas.

(B) Conventional technology As a conventional technology of this type of device, the other end of the non-condensable gas exhaust path on the atmosphere side is made of palladium metal that permeates hydrogen to the atmosphere side while being heated to a high temperature (200 ° C. or higher). Those equipped with a hydrogen gas discharge device (for example, Japanese Utility Model Publication No. 47-19
970) or a box containing a metal that absorbs hydrogen gas at room temperature or at high temperature and discharges it at a high temperature, which is provided in an exhaust passage for non-condensable gas by communicating with a vapor hydrogen gas discharge device (for example, Japanese Patent Publication No. 55-31387). No. publication) is known.

(C) Problems to be Solved by the Invention In the conventional device as described above, the joint between the hydrogen gas discharge device and the exhaust passage is made of a different metal (for example, palladium and copper, palladium and iron). , High temperature (200 ℃
Under the conditions above), the device is inferior in durability because it is easily corroded, and there is a problem that the vicinity of the joint is often damaged and the hermeticity cannot be maintained.

In view of this problem, the present invention has an object to provide a device of this type having excellent durability.

(D) Means for Solving the Problems The present invention, as a means for solving the above problems, includes a non-condensable gas exhaust path connecting a machine kept at atmospheric pressure or less and a vacuum pump or other exhaust device. This type of device is constructed by incorporating a metal hydride that intervenes a valve in the middle to occlude and release hydrogen at a pressure of atmospheric pressure or less near room temperature.

(E) Action In this type of device of the present invention, the hydrogen storage action and the hydrogen release action of the metal hydride are repeatedly exhibited at a lower temperature than the conventional one by the stoppage of the vacuum pump and other exhaust devices. Therefore, it is possible to discharge the non-condensable gas together with the hydrogen gas generated inside the machine to the outside of the machine, and to have the advantage of superior durability of the device compared to the conventional one that easily corrodes the exhaust passage under high temperature. Hold.

(F) Embodiments The drawings are schematic configuration diagrams showing an embodiment of an apparatus of this type according to the present invention. In the figure, (1) is a high temperature generator,
(2) is a separator, (3) is a generated condenser consisting of a low temperature generator (4) and a condenser (5), (6) is evaporative absorption consisting of an evaporator (7) and an absorber (8) Vessel, (9), (10) are low temperature and high temperature solution heat exchangers, (11) is a bubble pump for refrigerant liquid, (12) is a pump for absorbing liquid, and these are pipes (13) through which the refrigerant flows. , (14), (15),
(16), a pipe (17) for flowing down the refrigerant liquid, and a pipe (1 for returning the refrigerant liquid
8), (19), Pipes (20), (21), (22), (2
3), absorption liquid flow pipe (24), (25), (26), (27), pumping pipe
They are connected by (28) to form a circulation path for the refrigerant [water] and the absorption liquid [lithium bromide aqueous solution] similar to the conventional absorption refrigerator. Incidentally, (29) is a heat recovery device for recovering the heat of the refrigerant into the absorption liquid, and this heat recovery device is a bypass pipe (3
It was deployed in the middle of 0). Furthermore, (31) is a separator
A pipe for overflowing the absorbent that connects (2) and the low temperature generator (4).
A steam trap (32) is installed in the middle of this pipe.

Further, (33) is a pipeline connecting the separator (2) and the absorber (8), and a cold / hot switching valve (V ₀ ) is provided in this pipeline. Moreover, (34) is a conduit connecting the gas phase parts of these devices in order to flow the non-condensable gas in the generated condenser (3) to the evaporative absorber (6) side, and this conduit has a throttling mechanism. Other pressure regulators (3
5) is prepared.

(36) is the combustion heating chamber of the high temperature generator (1), (37) is a burner,
(38) is a heater of the low temperature generator (4), (39), (40) is a condenser (5), a cooler built in the absorber (8),
Further, (41) is a heat exchanger built in the evaporator (7). Incidentally, (42) is a heating coil of the bubble pump (11), and (43) is a heat exchange coil of the heat recovery unit (29).

(44) is a bleeding chamber connected to the vapor phase part of the evaporative absorber (6) by a bleeding pipe (a), and this bleeding chamber has a sprayer for the series liquid (45)
Is prepared. (46) is a temperature lowering device for lowering the temperature of the absorbing liquid in the container, and this temperature lowering device has a temperature decreasing coil (47) in which water flows. The cooling coil (47) has a water side pipe (4
8) and (49) are connected. (50) is a gas storage chamber for storing non-condensable gas. Also, (51) is a pipe from the absorption liquid reservoir (52).
(b) A container that keeps the liquid level in the container almost constant while allowing the absorption liquid sent by the pump (12) to overflow through the overflow pipe (d). The absorption liquid of (4) is made to flow down to the temperature lowering device (46). Then, the extraction chamber (44), the temperature reducer (46), the gas storage chamber (50) and the container (51) and the evaporation absorber (6) are pipes (b), (e),
(f), (g), (h), tube (u) having U-shaped portion and bleed tube
(a) and an overflow pipe (d) having a U-shaped portion are connected to form a non-condensable gas extraction device similar to the conventional extraction device.

Further, (53) is a reversing tank for absorbing liquid, and this level tank is divided into an absorbing liquid inlet side and an absorbing liquid side through a partition wall (54), and a pipe (u) is connected to the outlet side bottom part. On the other hand, the pipe (g) is connected to the inlet side, and the pipe (h) is connected to the uppermost part of the level tank (53). Further, a liquid level sensor (LS) for detecting the liquid level of the absorbing liquid is arranged on the absorbing liquid outlet side of the level tank (53). A pressure sensor (PS) is arranged in the gas storage chamber (50).

(55) is a device containing, for example, a zirconium-based metal hydride (X), and this device is provided with a heater (H). By appropriately selecting the composition of the zirconium-based metal hydride, the hydrogen storage action and the desorption action can be exhibited near room temperature, so the heater (H) is not always necessary [Chemical Engineering, Vol 2
8, No., 1983, P1 to 11, published by Kagaku Kogyo Co., Ltd.]. In addition, it is preferable that the metal hydride (X) is incorporated in the device (55) by interposing it between the partition plates (56) and (56) having a large number of minute holes.

And (P) is a vacuum pump, this vacuum pump and the device (55) are connected by a pipe (j) via a valve (V ₂ ), and
The device (55) and the gas storage chamber (50) are connected by a pipe (i) via a valve (V ₁ ).

(C) is a controller, and a pressure sensor (P
S) or the liquid level sensor (LS) signal controls opening / closing of the valves (V ₁ ) and (V ₂ ) and start / stop control of the vacuum pump (P). Note that the heater (H) may be started and stopped together with this control.

Next, the non-condensable gas removing device (hereinafter,
An operation example of this device) will be described.

With the above-mentioned bleeder, non-condensable gas such as hydrogen gas generated in the absorption chiller, air remaining in the absorption chiller or air entering the absorption chiller can be stored in the gas storage chamber (50 ). And the gas storage room
(50) Temperature where metal hydride (X) is inside pressure (eg normal temperature)
When the value reaches a value sufficiently higher than the equilibrium hydrogen town (at which the hydrogen pressure rises above this pressure and the hydrogen absorption starts in the metal hydride (X) above) (hereinafter referred to as the first set value), the pressure sensor The valve (V ₁ ) is opened by the signal of (PS). As a result, hydrogen gas is occluded by the metal hydride (X) and the internal pressure of the gas storage chamber (50) decreases. Then, the pressure inside the gas storage chamber (50) is close to the equilibrium hydrogen pressure of the metal hydride (X) (hereinafter referred to as the second
When it reaches the set value), the vacuum pump (P) is activated by the signal of the pressure sensor (PS), and then the valve (V ₂ ) is opened. As a result, the gas (hydrogen gas and other non-condensable gases) in the gas storage chamber (50) and the device (55) is exhausted, and the pressure in the gas storage chamber (50) and the device (55) decreases, and Accompanying this, hydrogen is dissociated from the metal hydride (X) to release hydrogen gas, and the hydrogen gas is also exhausted to the outside of the machine. And, the value below the hydrogen dissociation pressure of the metal hydride (X) [the pressure at which the hydrogen pressure drops and hydrogen starts to be released from the metal hydride (X) below this pressure] in the gas storage chamber (50). When (hereinafter, referred to as the third set value) is reached, the valves (V ₁ ) and (V ₂ ) are closed, and then the vacuum pump (P) is stopped. After that, hydrogen gas and the like can be removed by repeating the above operation. In this device, when the heater (H) is operated when the pressure-sensitive pressure of the pressure sensor (PS) reaches the second set value, more hydrogen can be dissociated, and more hydrogen can be released. There is an advantage that the metal hydride (X) can be occluded. For dogs, it is sufficient that the temperature of the heater (H) is about the same as or slightly higher than the temperature of the absorbing liquid. In addition, in the present invention, the level tank (L
Since the liquid level of S) also changes, it is possible to control by the liquid level sensor (LS) instead of the pressure sensor (PS).

In this device, the pressure sensor (PS) senses a partial pressure of gas other than hydrogen gas, but since this partial pressure is usually a small value, its effect is a minor sign.
Even in dogs, if a large amount of non-condensable gas other than hydrogen gas accumulates in the gas storage chamber (50), such as during trial operation, the first and second set values differ from the partial pressure of hydrogen gas, and the metal Hydride (X)
Although the hydrogen storage and desorption effects of the hydrogen are not exerted well, a large amount of non-condensable gas is also exhausted by the vacuum pump (P) and the internal pressure of the gas storage chamber (50) becomes 3rd as time elapses. In order to reach the set value, the above operation can be repeated thereafter. Therefore, this effect is only temporary, and hydrogen gas is also discharged outside the machine by the vacuum pump (P) together with the non-condensable gas, which adversely affects the performance of this device as a non-condensable gas removing device. It does not extend to. As the amount of air present in the absorbing liquid decreases, the cycle of opening and closing the valves (V ₁ ) and (V ₂ ) and starting / stopping the vacuum pump (P) also becomes longer, which does not adversely affect the life of this device. It does not reach.

In addition, this device does not necessarily have to include the valve (V ₁ ). If the valve (V ₁ ) is not provided, the pressure sensor (P
When the pressure detected in S) becomes higher than the second set value, the vacuum pump
(P) is activated to open the valve (V ₂ ), and when the pressure sensor (PS) becomes lower than the third set value, the valve (V ₂ ) is closed and the vacuum pump (P) is stopped.

In addition, in the present device, an ejector or the like may be used as the exhaust device of the non-condensable gas instead of using the vacuum pump (P), and the device (() is provided instead of providing the pressure chamber (PS) in the gas storage chamber (50). 55), the pipe (i) or the vapor phase part of the pipe (h).

Further, since this device operates near room temperature, it operates at high temperature and is less corrosive as in the conventional device having a joint such as a brazing part of dissimilar metals.

(G) Effect of the invention As described above, the non-condensable gas removing apparatus of the present invention comprises a metal hydride that performs hydrogen absorption and hydrogen desorption at a pressure of atmospheric pressure or less in the vicinity of normal temperature in the exhaust passage of the non-condensed gas, Moreover, since the internal pressure of this exhaust passage is adjusted by starting and stopping the exhaust system, the degree of corrosion is lower than that of the conventional one that constantly heats the palladium metal to a high temperature to allow hydrogen to permeate, and is durable. It is highly practical and has a high practical value because it can discharge non-condensable gases such as dissolved air other than hydrogen gas to the outside of the machine.

[Brief description of drawings]

The drawings are schematic structural explanatory views showing an embodiment of a non-condensable gas removing apparatus according to the present invention. (1) ... High temperature generator, (2) ... Separator, (3) ... Generating condenser, (6)
... Evaporative absorber, (8) ... Absorber, (12) ... Pump, (34) ... Pipe line, (44) ... Extraction chamber, (50) ... Gas storage chamber, (52) ... Absorption liquid reservoir, (53) ) ... Level tank, (55) ... Device, (C) ... Controller,
(P) ... Vacuum pump, (LS) ... Liquid level sensor, (PS)
... pressure _{sensor, (V 1), (V} 2) ... the valve, (X) ... metal hydride, (a), (g) , (h), (i), (j) ... tube.

Claims (2)

[Claims] 1. Hydrogen storage, hydrogen release, and room temperature in the middle of an exhaust passage connecting an absorption refrigerating machine or other machine kept under atmospheric pressure and a vacuum pump or other exhausting device for discharging non-condensable gas in the machine. An apparatus for removing non-condensable gas, characterized in that a metal hydride is provided in the vicinity under atmospheric pressure via a valve. 2. The non-condensable gas removing device according to claim 1, wherein opening / closing of the valve is switched and start / stop of the exhaust device is performed by an internal pressure of an exhaust passage in which the metal hydride is provided.