JP4301747B2 - Absorption refrigerator vacuum holding device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an absorption refrigerator using an absorption refrigeration cycle, and more particularly to a technique for extracting non-condensable gas in the absorption refrigeration cycle and maintaining the vacuum state of the absorption refrigeration cycle for a long period of time.
[0002]
[Prior art]
Since the absorption refrigeration cycle uses a highly corrosive absorbing liquid, when corrosion occurs in the absorption refrigeration cycle, insoluble non-condensable gas such as hydrogen gas is generated.
The non-condensable gas generated in the absorption refrigeration cycle is gradually accumulated in the absorber having the lowest internal pressure in the absorption refrigeration cycle. For this reason, the presence of non-condensable gas increases the internal pressure of the absorber and the evaporator. As a result, the boiling point of the refrigerant in the evaporator rises, the evaporation capacity decreases, and the refrigeration capacity of the absorption refrigeration cycle decreases.
[0003]
Therefore, conventionally, extraction means for extracting non-condensable gas generated in the absorption refrigeration cycle to the outside of the absorption refrigeration cycle and preventing an increase in the internal pressure of the absorber and the evaporator has been used. The noncondensable gas extracted to the outside of the absorption refrigeration cycle by the extraction means is stored in the noncondensable gas tank.
[0004]
[Problems to be solved by the invention]
The inside of the non-condensable gas tank is in a low pressure because it communicates with the absorber or the evaporator through the extraction means, and a large amount of non-condensable gas cannot be stored in the inside of the non-condensable gas tank. Therefore, it was necessary to periodically discharge the non-condensable gas accumulated in the non-condensable gas tank, which was troublesome. Therefore, if the internal pressure in the non-condensable gas tank is increased to increase the absolute amount of non-condensable gas that accumulates in the non-condensable gas tank, a part of the non-condensable gas is dissolved in the absorption liquid due to the increase in pressure, and the absorption refrigeration again The internal pressure in the non-condensable gas tank cannot be increased because it returns to the cycle.
[0005]
In addition, a technology is known in which a vacuum pump is connected to a non-condensable gas tank, and the non-condensable gas accumulated inside the non-condensable gas tank is discharged to the outside by periodically operating the vacuum pump. Since the cost of installation increases significantly, only a small portion of it is implemented.
[0006]
OBJECT OF THE INVENTION
The present invention has been made in view of the above circumstances, and its object is to eliminate the need for maintenance to discharge the non-condensable gas accumulated in the non-condensable gas tank to the outside without causing a significant increase in cost. Or it is in providing the vacuum holding | maintenance apparatus of the absorption refrigerator which can reduce the frequency | count of a maintenance.
[0007]
[Means for Solving the Problems]
The vacuum holding device of the absorption refrigerator of the present invention employs the following technical means in order to achieve the above object.
[Means of Claim 1]
The vacuum holding device of the absorption refrigerator is
a) heating means for heating the absorbent;
b) A regenerator that vaporizes a part of the absorbing liquid by heating the absorbing liquid by the heating means, a condenser that cools and liquefies the vaporized refrigerant generated in the regenerator, and a liquefied refrigerant that is liquefied by the condenser. An absorption refrigeration cycle comprising an evaporator that evaporates under low pressure, an absorber that absorbs vaporized refrigerant evaporated in the evaporator into an absorption liquid, and a solution pump that pumps the absorption liquid in the absorber to the regenerator;
c) a non-condensable gas tank for storing non-condensable gas inside;
d) a discharge valve provided at the upper portion of the non-condensable gas tank, for discharging the non-condensable gas inside the non-condensable gas tank to the outside;
e) extraction means for guiding noncondensable gas in the absorption refrigeration cycle to the noncondensable gas tank;
f) a check valve provided in a gas riser pipe that guides the non-condensable gas extracted by the extraction means to the non-condensable gas tank, and allows a fluid to flow only from the extraction means side to the non-condensable gas tank;
g) a check valve bypass pipe that bypasses the check valve, communicates the upstream side and the downstream side of the check valve, and flows the solution downstream of the check valve to the upstream side of the check valve; ,
h) Connected in the middle of the check valve bypass pipe, the absorption liquid pumped by the solution pump is led into the non-condensable gas tank through the check valve bypass pipe, and the liquid level in the non-condensable gas tank is raised. A solution pump tube to be
i) provided at a connection portion between the check valve bypass pipe and the solution pump pipe;
The solution pump pipe communicates with the downstream side of the check valve bypass pipe, and the first mode closes the upstream side of the check valve bypass pipe. The solution pump pipe is closed and the upstream side of the check valve bypass pipe is upstream. And a three-way switching valve that performs switching in the second mode for communicating the side and the downstream side.
[0008]
[Means of claim 2]
The vacuum holding device for an absorption refrigerator according to claim 1 is:
A low-level liquid level sensor provided in the middle of the check valve bypass pipe for detecting a liquid level drop in the non-condensable gas tank;
And a controller that controls the discharge valve and the three-way switching valve to discharge the non-condensable gas in the non-condensable gas tank when the low level liquid level sensor detects a drop in the liquid level.
[0009]
[Means of claim 3]
The vacuum holding device for an absorption refrigerator according to claim 2 is:
A high-level liquid level sensor for detecting an increase in the liquid level in the non-condensable gas tank, and the control device detects the discharge valve and the three-way switching valve when the high-level liquid level sensor detects an increase in the liquid level. To finish the discharge operation of the non-condensable gas in the non-condensable gas tank.
[0010]
[Operation and effect of the invention]
[Operation and effect of claim 1]
When discharging the non-condensable gas accumulated in the non-condensable gas tank to the outside, the three-way switching valve is switched to the first mode. Then, the solution pumped by the solution pump is supplied into the non-condensable gas tank through the solution pump pipe, the liquid level in the non-condensable gas tank rises, and the non-condensable gas is compressed to a high pressure. At this time, by opening the discharge valve, the high-pressure non-condensable gas stored inside the non-condensable gas tank is discharged to the outside of the non-condensable gas tank (for example, in the atmosphere). At this time, since the pressure in the non-condensable gas tank is larger than the atmospheric pressure, air does not enter the non-condensable gas tank, and the vacuum state in the non-condensable gas tank is maintained.
When the discharge of the non-condensable gas is completed, the three-way switching valve is switched to the second mode. Then, the solution supplied into the non-condensable gas tank is flowed to the upstream side of the check valve via the check valve bypass pipe, that is, the extraction means side, and the inside of the non-condensable gas tank becomes low pressure and extracted by the extraction means. Non-condensable gas is easily collected.
[0011]
As described above, in the present invention, since the non-condensable gas stored in the non-condensable gas tank can be discharged to the outside, the degree of vacuum in the absorption refrigeration cycle can be maintained over a long period of time. It is possible to prevent a reduction in the capacity of the absorption refrigeration cycle due to gas.
Moreover, in this invention, the non-condensable gas stored inside the non-condensable gas tank can be discharged outside even during the operation of the absorption refrigeration cycle.
[0012]
Furthermore, in the present invention, the non-condensable gas stored inside the non-condensable gas tank is discharged to the outside by the discharge pressure of the solution pump mounted in the absorption refrigeration cycle. This is unnecessary, and the number of maintenance can be eliminated or reduced without incurring a significant cost increase.
[0013]
[Operation and effect of claim 2]
When the non-condensable gas stored in the non-condensable gas tank increases, the stored non-condensable gas lowers the liquid level. When the low level liquid level sensor detects a decrease in the liquid level in the non-condensable gas tank, the control device automatically discharges the non-condensable gas. As described above, the non-condensable gas discharging operation is automatically performed, so that the non-condensable gas discharging operation is not troublesome.
[0014]
[Operation and effect of claim 3]
The liquid level in the non-condensable gas tank rises due to the discharge operation of the non-condensable gas. When the high level liquid level sensor detects that the liquid level in the non-condensable gas tank has risen to a predetermined level or higher, the control device automatically finishes discharging the non-condensable gas. For this reason, there is no problem that the solution supplied into the non-condensable gas tank leaks to the outside through the discharge valve.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described based on two examples and modifications.
[Configuration of the first embodiment]
1 to 6 are drawings for explaining the first embodiment, and FIG. 1 is a schematic configuration diagram of an absorption type air conditioner that performs indoor air conditioning using an absorption refrigerator.
[0016]
(Outline explanation of absorption type air conditioner)
The absorption type air conditioner includes an outdoor unit 1 and an indoor unit 2, and the outdoor unit 1 includes a refrigerator main body 3 and a cooling tower 4. Each mounted electric functional component is controlled by a control device 5. Is done.
The refrigerator main body 3 is mainly formed of stainless steel and forms an absorption cycle using a lithium bromide aqueous solution as a refrigerant and an absorption liquid. The heating means 6 for heating the absorption liquid and a double-effect absorption A refrigeration cycle 7.
[0017]
(Description of heating means 6)
The heating means 6 of this embodiment is a gas combustion device that burns gas as fuel to generate heat, and heats the absorbing liquid by the generated heat. The gas burner 11 performs gas combustion, and gas is supplied to the gas burner 11. It comprises a gas supply means 12 that supplies gas, a combustion fan 13 that supplies combustion air to the gas burner 11, and the like.
Then, the heat obtained by the gas combustion of the gas burner 11 is used to heat the boiling device 14 of the absorption refrigeration cycle 7 and heat the low-concentration absorbing liquid (hereinafter, low liquid) supplied into the boiling device 14. Is provided.
[0018]
(Description of absorption refrigeration cycle 7)
The absorption refrigeration cycle 7 includes a boiling device 14 that is heated by the heating means 6, and the low liquid supplied into the boiling device 14 is heated to vaporize (evaporate) the refrigerant (water) contained in the low liquid. ) By using the high temperature regenerator 15 to be an intermediate concentration absorbing liquid (hereinafter referred to as “medium liquid”) and the condensation heat of the vaporized refrigerant in the high temperature regenerator 15, using the pressure difference from the high temperature regenerator 15 side. From the low temperature regenerator 16, the high temperature regenerator 15 and the low temperature regenerator 16 which heats the supplied intermediate liquid and vaporizes the refrigerant contained in the intermediate liquid to make the intermediate liquid a high-concentration absorption liquid (hereinafter, high liquid). The condenser 17 that cools and liquefies the vaporized refrigerant (water vapor), the evaporator 18 that evaporates the liquefied refrigerant (water) liquefied by the condenser 17 under a pressure close to vacuum, and the evaporator 18 evaporates. Absorption by which vaporized refrigerant is absorbed by the high liquid obtained by the low temperature regenerator 16 It consists of 19 Metropolitan.
[0019]
(Description of high temperature regenerator 15)
The high-temperature regenerator 15 includes the above-described boiling device 14 that heats the low liquid by the heating unit 6, and the boiling cylinder 21 that extends upward from the boiling device 14. The vaporized refrigerant that has been boiled in the boiling device 14 and the boiling cylinder 21 and vaporized from a low liquid is blown out from the boiling cylinder 21 into the high-temperature regeneration case 22 having a cylindrical container shape. The high-temperature vaporized refrigerant blown into the high-temperature regeneration case 22 is cooled by the wall of the high-temperature regeneration case 22 by removing heat as vaporization heat at the time of evaporation of the medium liquid in the low-temperature regenerator 16 to be liquefied refrigerant (water )become.
[0020]
Inside the boiling cylinder 21 of this embodiment is arranged a cup-shaped partition container 21a for storing the medium liquid after being blown into the boiling cylinder 21 and the refrigerant is vaporized, and the intermediate liquid stored in the inside is stored. It is supplied to the low temperature regenerator 16 through the middle liquid pipe 23. The middle liquid pipe 23 is provided with a throttle means (not shown) such as an orifice. When the cooling / heating switching valve 53 (to be described later) is closed, this throttling means allows the medium liquid to flow while maintaining the pressure difference between the high-temperature regenerator 15 and the low-temperature regenerator 16, and when the cooling / heating switching valve 53 is opened, Almost no flow.
Further, an absorption liquid return plate 21b is provided on the upper portion of the partition container 21a, and is provided so that the absorption liquid blown out in the boiling cylinder 21 is guided into the partition container 21a.
[0021]
In order to insulate the inside of the high-temperature regeneration case 22 from the medium liquid in the boiling cylinder 21 after the refrigerant in the low liquid is vaporized by being heated by the boiling device 14, and the liquefied refrigerant (water) stored around the inside. In addition, a heat insulating gap 24 is provided around the boiling cylinder 21.
The liquefied refrigerant (water) liquefied in the high temperature regeneration case 22 and separated to the outside of the boiling cylinder 21 is guided to the condenser 17 through the liquid refrigerant pipe 25 connected to the lower part.
[0022]
(Description of low temperature regenerator 16)
The low temperature regenerator 16 includes a cylindrical container-shaped low temperature regeneration case 31 that covers the high temperature regeneration case 22. The low temperature regenerator 16 injects the intermediate liquid supplied through the intermediate liquid pipe 23 toward the ceiling portion of the high temperature regeneration case 22.
Since the temperature in the low temperature regeneration case 31 is lower than the temperature in the high temperature regeneration case 22, the pressure in the low temperature regeneration case 31 is lower than the pressure in the high temperature regeneration case 22. For this reason, the intermediate liquid supplied from the intermediate liquid pipe 23 into the low temperature regeneration case 31 is likely to evaporate. Then, when the medium liquid is injected into the ceiling portion of the high temperature regeneration case 22, the medium liquid is heated by the wall of the high temperature regeneration case 22, and a part of the refrigerant contained in the medium liquid evaporates to become a vaporized refrigerant, and remains. Becomes high liquid.
[0023]
Here, the upper side of the low-temperature regeneration case 31 communicates with the upper side of the annular container-shaped condensing case 32 via the communication portion 33. For this reason, the vaporized refrigerant evaporated in the low temperature regeneration case 31 is supplied into the condensation case 32 through the communication portion 33.
On the other hand, the high liquid falls to the lower part of the low temperature regeneration case 31 and is supplied to the absorber 19 through the high liquid pipe 34 connected to the lower part of the low temperature regeneration case 31.
A ceiling plate 35 is provided on the upper side in the low temperature regeneration case 31, and a gap 36 through which the vaporized refrigerant passes is provided between the outer peripheral end of the ceiling plate 35 and the low temperature regeneration case 31.
[0024]
(Description of condenser 17)
The condenser 17 is covered with a condensing case 32 having an annular container shape. Inside the condensing case 32, a condensing heat exchanger 37 for cooling and liquefying the vaporized refrigerant in the condensing case 32 is disposed. The condensing heat exchanger 37 is an annular coil in which cooling water flows. Then, the liquefied refrigerant supplied from the low-temperature regenerator 16 into the condensation case 32 is cooled and liquefied by the condensation heat exchanger 37, and is dropped below the condensation heat exchanger 37.
[0025]
On the other hand, the refrigerant is supplied to the lower side of the condensing case 32 through the liquid refrigerant pipe 25 from the high temperature regenerator 15 described above. In addition, when this supply refrigerant | coolant is supplied in the condensation case 32, it is reboiled from the difference in pressure (the inside of the condensation case 32 is a low pressure of about 70 mmHg), and is supplied in a state where the vaporized refrigerant and the liquefied refrigerant are mixed. Is done. The liquefied refrigerant liquefied in the condensation case 32 is guided to the evaporator 18 via the liquid refrigerant supply pipe 38.
[0026]
(Description of the evaporator 18)
The evaporator 18 is provided in the lower part of the condensation case 32 together with the absorber 19, and is covered with an annular container-shaped evaporation / absorption case 41 provided around the low temperature regeneration case 31. An evaporation heat exchanger 42 for evaporating the liquefied refrigerant supplied from the condenser 17 is disposed outside the evaporation / absorption case 41. The evaporating heat exchanger 42 is an annular coil, in which cold / hot water (heat medium) supplied to the indoor unit 2 flows. The liquefied refrigerant supplied from the condenser 17 via the liquid refrigerant supply pipe 38 is supplied to the annular refrigerant spreader 43 via the refrigerant boiling device 43a disposed at the upper part of the evaporation heat exchanger 42, The refrigerant is spread on the evaporation heat exchanger 42 from the refrigerant spreader 43.
[0027]
Since the inside of the evaporation / absorption case 41 is maintained almost in a vacuum (for example, 6.5 mmHg), the boiling point is low, and the liquefied refrigerant sprayed on the evaporation heat exchanger 42 is very easily evaporated. The liquefied refrigerant sprayed on the evaporation heat exchanger 42 evaporates by removing the heat of vaporization from the heat medium flowing in the evaporation heat exchanger 42.
As a result, the heat medium flowing in the evaporation heat exchanger 42 is cooled. The cooled heat medium is guided to the indoor unit 2 to cool the room.
[0028]
(Description of absorber 19)
The absorber 19 is covered with the evaporation / absorption case 41 as described above. In the absorber 19, an absorption heat exchanger 44 that cools the high liquid supplied from the high liquid pipe 34 is disposed inside the evaporation / absorption case 41. The absorption heat exchanger 44 is an annular coil, and is supplied with cooling water for cooling the high liquid sprayed on the coil. The cooling water that has passed through the absorption heat exchanger 44 passes through the condensation heat exchanger 37 of the condenser 17 and is then guided to the cooling tower 4 to be cooled. Then, the cooling water cooled by the cooling tower 4 is led to the absorption heat exchanger 44 again.
[0029]
On the other hand, on the upper part of the absorption heat exchanger 44, an annular absorption liquid spraying tool 45 that disperses the high liquid supplied from the high liquid pipe 34 to the absorption heat exchanger 44 is disposed. While the high liquid sprayed on the absorption heat exchanger 44 travels down the coil surface of the absorption heat exchanger 44 and falls downward from above, the vaporized refrigerant generated by evaporation in the evaporation heat exchanger 42 is removed. Absorb. As a result, the absorption liquid that has dropped to the bottom of the evaporation / absorption case 41 becomes a low liquid with a low concentration.
[0030]
Inside the evaporation / absorption case 41, a cylindrical partition wall 46 is disposed between the evaporation heat exchanger 42 and the absorption heat exchanger 44. The cylindrical partition wall 46 communicates with the inside of the evaporation / absorption case 41 only at the upper side, and the vaporized refrigerant generated by the evaporator 18 is introduced into the absorber 19 through the upper part of the cylindrical partition wall 46. It is burned.
[0031]
Further, a low liquid pipe 47 for supplying low liquid at the bottom of the evaporation / absorption case 41 to the boiling device 14 is connected to the bottom of the evaporation / absorption case 41. The low liquid pipe 47 is provided with a solution pump 48 for allowing the low liquid to flow from the evaporation / absorption case 41 in a substantially vacuum state toward the boiling device 14.
[0032]
(Description of components other than the above in the absorption refrigeration cycle 7)
Reference numeral 51 shown in FIG. 1 denotes a high temperature heat exchanger 51 a that exchanges heat between the middle liquid flowing from the inside of the boiling cylinder 21 to the low temperature regenerator 16 and the low liquid flowing from the absorber 19 to the boiler 14, and the low temperature regenerator 16. It is a heat exchanger in which a high-temperature liquid flowing to the absorber 19 and a low-temperature heat exchanger 51b that exchanges heat between the low liquid flowing from the absorber 19 to the boiling device 14 are integrated.
The high temperature heat exchanger 51a cools the intermediate liquid flowing from the boiling cylinder 21 to the low temperature regenerator 16, and conversely heats the low liquid flowing from the absorber 19 to the boiling device 14. The low temperature heat exchanger 51b cools the high liquid flowing from the low temperature regenerator 16 to the absorber 19, and conversely heats the low liquid flowing from the absorber 19 to the boiling device 14.
[0033]
Further, the absorption refrigeration cycle 7 of the present embodiment is provided with a heating operation means for performing a heating operation in addition to the cooling operation by the above-described operation.
The heating operation means includes a heating pipe 52 that guides the absorbing liquid having a high temperature from the lower part of the partition container 21 a to the lower part of the evaporator 18, and a cooling / heating switching valve 53 that opens and closes the heating pipe 52. The cooling / heating switching valve 53 is opened during heating operation, guides the high-temperature absorption liquid into the evaporation / absorption case 41, and heats the cold / hot water flowing in the evaporation heat exchanger 42 of the evaporator 18.
[0034]
(Explanation of indoor unit 2)
The indoor unit 2 forcibly exchanges heat between the indoor heat exchanger 54 installed indoors, the cold / hot water that has passed through the evaporator 18 that flows through the indoor heat exchanger 54, and the room air, and the air after the heat exchange And an indoor fan 55 for blowing out into the room.
The indoor heat exchanger 54 is connected to a cold / hot water circuit 56 for circulating cold / hot water, and the cold / hot water circuit 56 is provided with a cold / hot water pump 57 for circulating cold / hot water. The cold / hot water pump 57 is driven by a dual-purpose motor that drives the solution pump 48.
[0035]
(Description of cooling tower 4)
The cooling tower 4 flows the cooling water that has been heated through the absorber 19 and the condenser 17 from the upper side to the lower side, exchanges heat with the outside air while flowing, and dissipates heat. The cooling water is cooled by evaporating to remove the heat of vaporization, and includes a cooling water fan 61 that promotes evaporation and cooling of the cooling water. A cooling water circuit 62 for circulating cooling water is connected to the cooling tower 4, and the cooling water is circulated by a cooling water pump 63.
[0036]
(Cooling operation by absorption refrigeration cycle 7)
In the absorption refrigeration cycle 7, when the heating unit 6 heats the boiling device 14, the high temperature regenerator 15 extracts vaporized refrigerant from the low liquid, and the low temperature regenerator 16 extracts high liquid from the medium solution. .
The vaporized refrigerant taken out by the high-temperature regenerator 15 and the low-temperature regenerator 16 is condensed and liquefied by the condenser 17, and then sprayed to the evaporation heat exchanger 42 of the evaporator 18. It evaporates by removing heat of vaporization from cold and hot water. For this reason, the cooled / warm water that has passed through the evaporation heat exchanger 42 and is cooled is supplied to the indoor heat exchanger 54 of the indoor unit 2 to cool the room.
[0037]
The vaporized refrigerant evaporated in the evaporator 18 passes over the cylindrical partition wall 46 and flows into the absorber 19.
On the other hand, in the absorber 19, the high liquid taken out by the low-temperature regenerator 16 is dispersed in the absorption heat exchanger 44, and the vaporized refrigerant flowing from the evaporator 18 is absorbed by this high liquid. The absorption heat generated when the vaporized refrigerant is absorbed by the high liquid is absorbed by the absorption heat exchanger 44 to prevent a decrease in absorption capacity.
Note that the high liquid that has absorbed the vaporized refrigerant by the absorber 19 becomes a low liquid and is sucked by the solution pump 48 and is returned to the boiling device 14 again, and the above cycle is repeated.
[0038]
(Description of non-condensable gas collection means)
The absorption air conditioner includes non-condensable gas collecting means for collecting and storing non-condensable gas such as hydrogen generated due to corrosion in the absorption refrigeration cycle 7 outside the absorption refrigeration cycle 7. The configuration of the non-condensable gas collecting means will be described with reference to FIGS. 2 to 5 in addition to FIG.
The non-condensable gas collecting means includes an extraction means 70 for extracting the non-condensable gas of the absorption refrigeration cycle 7 to the outside, and a non-condensable gas tank 71 for storing the non-condensable gas extracted to the outside by the extraction means 70.
[0039]
The extraction means 70 includes an ejector 72 that mixes the non-condensable gas accumulated in the lower part of the absorber 19 into the absorption liquid pumped from the solution pump 48, and a gas-liquid that separates the non-condensable gas from the absorption liquid mixed with the non-condensable gas. And a separator 73.
The ejector 72 includes a bleed pipe 74 a that guides the non-condensable gas stored in the lower part of the absorber 19 into the ejector 72, and a part of the absorption liquid pumped from the solution pump 48 in the suction opening 75 in the ejector 72. The non-condensable gas is sucked from the suction opening 75 together with the absorbing liquid by the spraying force of the absorbing liquid sprayed from the nozzle 76. The absorbing liquid is pumped to the nozzle 76 via an ejector low liquid pipe 77 branched from the low liquid pipe 47.
[0040]
The gas-liquid separator 73 is disposed below the ejector 72 and the non-condensable gas tank 71, and separates the absorption liquid flowing out from the nozzle 76 communicating with the suction opening 75 and the sucked non-condensable gas, The separated gas is guided to the non-condensable gas tank 71 and the separated absorption liquid is returned into the absorption refrigeration cycle 7.
The gas-liquid separator 73 of this embodiment is connected to the lower part of the non-condensable gas tank 71 and has an outer tube 78 having a J or U shape whose other end covers and closes the nozzle 76 of the ejector 72 and one end. Is provided with a suction opening 75 facing the nozzle 76, and the other end is constituted by an inner pipe 79 having a J-shape or U-shape opening in the rising portion on the non-condensable gas tank 71 side in the outer pipe 78.
A portion of the outer pipe 78 that guides the non-condensable gas discharged from the inner pipe 79 to the non-condensable gas tank 71 corresponds to the gas rising pipe 80.
[0041]
(Operation of extraction means 70)
In the absorption refrigeration cycle 7, corrosion occurs little by little by the action of a highly corrosive absorbing solution, and non-condensable gas such as hydrogen gas is generated. The generated non-condensable gas collects in the absorber 19 having a low pressure.
During operation of the absorption refrigeration cycle 7, a part of the absorbing liquid pumped from the solution pump 48 is discharged from the nozzle 76 into the suction opening 75. At this time, the non-condensable gas in the absorber 19 is sucked into the suction opening 75 due to the ejector effect of the absorbing liquid. The absorbing liquid mixed with the non-condensable gas sucked into the suction opening 75 is gas-liquid separated by the gas-liquid separator 73, and the separated non-condensable gas is guided to the non-condensable gas tank 71 through the gas rising pipe 80. The separated absorption liquid is returned into the evaporator 18 through a solution return pipe 74b that connects the outer pipe 78 and the inside of the absorber.
[0042]
(Description of gas discharge device)
A gas discharge device is provided for discharging the non-condensable gas accumulated in the non-condensable gas tank 71 into the atmosphere. This gas discharge device discharges the non-condensable gas accumulated in the non-condensable gas tank 71 so that the non-condensable gas can be always supplied into the non-condensable gas tank 71, and the evaporator 18 in the absorption refrigeration cycle 7. In addition, the vacuum state of the absorber 19 is always kept, and the performance of the absorption refrigeration cycle 7 is kept high.
[0043]
This gas discharge device guides the absorption liquid pumped by the solution pump 48 into the non-condensable gas tank 71, raises the liquid level of the non-condensable gas tank 71, and discharges the non-condensable gas accumulated inside to the outside. A solution pump pipe 81 for supplying the absorption liquid pumped by the solution pump 48 into the non-condensable gas tank 71, and the absorption liquid supplied from the solution pump pipe 81 into the non-condensable gas tank 71 through the gas-liquid separator 73. And a check valve 82 for preventing return to the absorber 19.
This check valve 82 is provided in the gas riser pipe 80 that guides the non-condensable gas separated by the gas-liquid separator 73 to the non-condensable gas tank 71 and is non-condensed from the gas-liquid separator 73 side (upstream side). The fluid is allowed to flow only on the gas tank 71 side (downstream side).
[0044]
In addition, the gas riser pipe 80 bypasses the check valve 82, communicates the upstream side and the downstream side of the check valve 82, and allows the gas-liquid separator 73 to absorb the absorption liquid supplied into the non-condensable gas tank 71. A check valve bypass pipe 83 is connected to return to the absorption refrigeration cycle 7.
On the other hand, the solution pump pipe 81 described above is connected in the middle of the check valve bypass pipe 83, and the connection portion between the solution pump pipe 81 and the check valve bypass pipe 83 is opposite to the solution pump pipe 81. A first mode in which the downstream side of the check valve bypass pipe 83 communicates and the upstream side of the check valve bypass pipe 83 is closed; the solution pump pipe 81 is closed; and the upstream side and the downstream side of the check valve bypass pipe 83 Is provided with a three-way switching valve 84 that can be switched between the second mode and the second mode. The three-way switching valve 84 is an electromagnetic switching valve that operates by energization control, and is set to the first mode when energized and set to the second mode when energization is stopped.
[0045]
That is, when the three-way switching valve 84 is switched to the first mode, the solution pump pipe 81 is opened to supply the absorption liquid pumped by the solution pump 48 into the non-condensable gas tank 71 and upstream of the check valve bypass pipe 83. The side is closed, and the trouble that the absorbing liquid flows to the upstream side of the check valve 82 is prevented.
Further, when the three-way switching valve 84 is switched to the second mode, the solution pump pipe 81 is closed, the supply of the absorption liquid pumped from the solution pump 48 is shut off, and the upstream side and the downstream side of the check valve bypass pipe 83 are blocked. The absorbing liquid supplied in the non-condensable gas tank 71 with the sides communicating can flow to the upstream side of the check valve 82.
[0046]
A discharge valve 85 for discharging the non-condensable gas in the non-condensable gas tank 71 to the outside is provided at the upper part of the non-condensable gas tank 71. The discharge valve 85 is an electromagnetic on-off valve that is operated by energization control, and is set to a state where the valve is opened while energized to discharge non-condensable gas, and is closed when the energization is stopped. It is.
In this embodiment, an example in which the non-condensable gas discharged from the non-condensable gas tank 71 is released to the atmosphere is shown.
[0047]
On the other hand, in this embodiment, a low level liquid level sensor 86 is provided for detecting that the noncondensable gas in the noncondensable gas tank 71 is increased and the liquid level is lowered by a predetermined amount or more. The low level liquid level sensor 86 is provided in the middle of the check valve bypass pipe 83 as shown in FIGS. 2 to 5, but provided at other positions such as the lower part in the non-condensable gas tank 71. Also good. The low level liquid level sensor 86 of this embodiment uses a switch that is turned ON when the liquid level is lowered.
Further, in this embodiment, when the liquid level rises by the absorbing liquid supplied into the non-condensable gas tank 71 via the solution pump pipe 81, the high level liquid level that detects that the liquid level has reached a predetermined amount or more is detected. A sensor 87 is provided in the upper part of the non-condensable gas tank 71. The high level liquid level sensor 87 of this embodiment uses a switch that is turned on when the liquid level rises.
[0048]
The gas discharge device is operated by a three-way switching valve 84 and a discharge valve 85. The three-way switching valve 84 and the discharge valve 85 are controlled based on detection results of the low level liquid level sensor 86 and the high level liquid level sensor 87. It is controlled by the device 5. In this embodiment, the gas discharge device is operated during the operation of the absorption refrigeration cycle 7 to discharge the non-condensable gas in the non-condensable gas tank 71. An operation example of the gas discharge device is shown in FIG. The operation will be described with reference to FIG. 5 and FIG.
[0049]
(Explanation of operation of gas discharge device)
During the operation of the absorption refrigeration cycle 7, it is determined whether or not the low level liquid level sensor 86 is turned on (step S1). If the result of this determination is NO, as shown in FIG. 2, the liquid level has not dropped to the low level liquid level sensor 86, and step S1 is repeated.
When the amount of non-condensable gas in the non-condensable gas tank 71 increases and the liquid level decreases to the position of the low level liquid level sensor 86 as shown in FIG. 3, the determination result in step S1 becomes YES. Then, the control apparatus 5 operates a gas discharge apparatus. That is, the three-way switching valve 84 is turned on to switch to the first mode (step S2), the discharge valve 85 is turned on to open the valve (step S3), and then whether or not the high level liquid level sensor 87 is turned on. A determination is made (step S4).
[0050]
While the determination result in step S4 is NO, the three-way switching valve 84 is switched to the first mode and the discharge valve 85 is opened. When the three-way switching valve 84 is switched to the first mode, the solution pump pipe 81 communicates with the downstream side of the check valve bypass pipe 83 and the upstream side of the check valve bypass pipe 83 is shut off. As a result, the absorption liquid is supplied from the solution pump pipe 81 into the non-condensable gas tank 71, the liquid level in the non-condensable gas tank 71 rises, and the non-condensable gas is compressed to a high pressure. At this time, since the discharge valve 85 is opened, the high-pressure non-condensable gas accumulated in the non-condensable gas tank 71 is discharged to the atmosphere via the discharge valve 85. At this time, since the pressure in the non-condensable gas tank 71 is larger than the atmospheric pressure, air does not enter the non-condensable gas tank 71 and the vacuum state in the non-condensable gas tank 71 is maintained.
[0051]
When the liquid level of the absorbing liquid in the non-condensable gas tank 71 rises and the liquid level rises to the position of the high level liquid level sensor 87 as shown in FIG. 4, the determination result in step S4 becomes YES. Then, the control device 5 stops the gas discharge device. That is, the discharge valve 85 is turned off to close it (step S5), and the three-way switching valve 84 is turned off to switch to the second mode (step S6).
Then, as shown in FIG. 5, the solution pump pipe 81 is closed, and the check valve bypass pipe 83 communicates the upstream and downstream of the check valve 82. Then, the absorption liquid supplied into the non-condensable gas tank 71 is sucked into the evaporator 18 via the check valve bypass pipe 83, the gas-liquid separator 73, and the solution return pipe 74 b and returned to the absorption refrigeration cycle 7. It is.
As a result, the pressure in the non-condensable gas tank 71 decreases, so that the non-condensable gas tank 71 returns to a state where non-condensable gas is easily stored.
[0052]
[Effects of Examples]
As shown in the above operation, when the amount of non-condensable gas in the non-condensable gas tank 71 is automatically checked during the operation of the absorption refrigeration cycle 7 and the amount of the non-condensable gas increases from a predetermined amount, The discharge device is automatically operated to discharge the non-condensable gas stored in the non-condensable gas tank 71 to the outside.
For this reason, the vacuum degree in the absorption refrigeration cycle 7 can be maintained over a long period of time, and a reduction in the capacity of the absorption refrigeration cycle 7 due to non-condensable gas can be prevented.
[0053]
Since the non-condensable gas stored in the non-condensable gas tank 71 is discharged to the outside by the discharge pressure of the solution pump 48 mounted in the absorption refrigeration cycle 7, a dedicated exhaust gas for discharging the non-condensable gas is provided. No vacuum pump is needed. For this reason, it is possible to eliminate maintenance for discharging the non-condensable gas accumulated in the non-condensable gas tank 71 to the outside without causing a significant cost increase.
[0054]
Every time the amount of the non-condensable gas stored in the non-condensable gas tank 71 reaches a predetermined amount, the non-condensable gas in the absorption refrigeration cycle 7 is repeatedly discharged to the atmosphere. Even if the airtightness of the collecting means is lowered, the inside of the absorption refrigeration cycle 7 can always be kept in a vacuum. In other words, the airtightness required for the absorption refrigeration cycle 7 and the non-condensable gas collecting means can be reduced.
[0055]
[Second Embodiment]
A second embodiment will be described with reference to FIG. In the second embodiment, a non-condensable gas tank 71 having the same diameter as the gas riser pipe is provided on the upper part of the gas riser pipe 80, and the upper part of the gas riser pipe 80 may be used as the non-condensable gas tank 71. .
By providing in this way, the amount of gas stored in the non-condensable gas tank 71 is reduced, so that the frequency of discharge work increases. However, the outdoor unit 1 on which the non-condensable gas tank 71 is mounted can be made compact.
[0056]
[Modification]
In the above embodiment, the discharge valve 85 is constituted by an electromagnetic opening / closing valve, and the valve opening control is performed by the control device 5. However, using a mechanical opening / closing valve that closes the valve by the biasing force of the spring, When the liquid level in the non-condensable gas tank 71 is raised and the internal pressure rises to a predetermined value or more, the non-condensable gas stored in the non-condensable gas tank 71 may be discharged to the outside.
In the above embodiment, an example in which the ejector 72 is used as an example of the extraction means 70 has been shown. However, the non-condensable gas is extracted outside the absorption refrigeration cycle 7 using another extraction means such as an auxiliary absorber. Also good.
[0057]
In the above embodiment, a double effect type is shown as an example of the absorption refrigeration cycle 7, but a single effect type or a triple effect type of triple effect or more may be used. Moreover, when injecting the middle liquid into the low temperature regenerator 16, the example of injecting from above the low temperature regenerator 16 has been shown, but it may be injected from below.
[0058]
Although the gas burner 11 is used as a heating source of the heating means 6, an oil burner or an electric heater may be used, or exhaust heat from another device (for example, an internal combustion engine) may be used.
Although the example which provided the heat exchanger 37 for condensation, the heat exchanger 42 for evaporation, and the heat exchanger 44 for absorption in the coil shape was shown, other types of heat exchangers, such as a tube-and-fin and a laminated heat exchanger, were shown. May be used.
[0059]
As an example of the absorbing solution, an aqueous lithium bromide solution is shown as an example. However, as another aqueous salt solution, for example, a ternary aqueous solution obtained by adding lithium iodide to an aqueous lithium bromide solution may be used. Other absorbents such as an aqueous ammonia solution using water as the agent may be used.
As an example of the heat medium, tap water is used and shared with the cooling water of the cooling water circuit. However, other heat medium such as antifreeze or oil different from the cooling water of the cooling water circuit may be used.
[0060]
Although an example in which the low level liquid level sensor 86 is arranged in the middle of the check valve bypass pipe 83 is shown, it may be arranged in the gas rising pipe 80.
The low level liquid level sensor 86 may be abolished, and a non-condensable gas discharge operation may be periodically started using a timer.
The high level liquid level sensor 87 may be abolished, and the discharge operation may be terminated when a certain time has elapsed since the start of the discharge operation of the non-condensable gas using a timer.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a main part of an absorption refrigerator (first embodiment).
FIG. 2 is an operation explanatory view of the gas discharge device (first embodiment).
FIG. 3 is an operation explanatory view of the gas discharge device (first embodiment).
FIG. 4 is an operation explanatory view of the gas discharge device (first embodiment).
FIG. 5 is an operation explanatory view of the gas discharge device (first embodiment).
FIG. 6 is a flowchart showing the operation of the gas discharge device (first embodiment).
FIG. 7 is a schematic view of a gas discharge device (second embodiment).
[Explanation of symbols]
5 Control device
6 Heating means
7 Absorption refrigeration cycle
15 High temperature regenerator
16 Low temperature regenerator
17 Condenser
18 Evaporator
19 Absorber
48 Solution pump
70 Extraction means
71 Noncondensable gas tank
80 Gas riser
81 Solution pump pipe
82 Check valve
83 Check valve bypass pipe
84 Three-way switching valve
85 Discharge valve
86 Low level liquid level sensor
87 High level liquid level sensor

Claims (3)

a) heating means for heating the absorbent;
b) A regenerator that vaporizes a part of the absorbing liquid by heating the absorbing liquid by the heating means, a condenser that cools and liquefies the vaporized refrigerant generated in the regenerator, and a liquefied refrigerant that is liquefied by the condenser. An absorption refrigeration cycle comprising an evaporator that evaporates under low pressure, an absorber that absorbs vaporized refrigerant evaporated in the evaporator into an absorption liquid, and a solution pump that pumps the absorption liquid in the absorber to the regenerator;
c) a non-condensable gas tank for storing non-condensable gas inside;
d) a discharge valve provided at the upper portion of the non-condensable gas tank, for discharging the non-condensable gas inside the non-condensable gas tank to the outside;
e) extraction means for guiding noncondensable gas in the absorption refrigeration cycle to the noncondensable gas tank;
f) a check valve provided in a gas riser pipe that guides the non-condensable gas extracted by the extraction means to the non-condensable gas tank, and allows a fluid to flow only from the extraction means side to the non-condensable gas tank;
g) a check valve bypass pipe that bypasses the check valve, communicates the upstream side and the downstream side of the check valve, and flows the solution downstream of the check valve to the upstream side of the check valve; ,
h) Connected in the middle of the check valve bypass pipe, the absorption liquid pumped by the solution pump is led into the non-condensable gas tank through the check valve bypass pipe, and the liquid level in the non-condensable gas tank is raised. A solution pump tube to be
i) provided at a connection portion between the check valve bypass pipe and the solution pump pipe;
The solution pump pipe communicates with the downstream side of the check valve bypass pipe, and the first mode closes the upstream side of the check valve bypass pipe. The solution pump pipe is closed and the upstream side of the check valve bypass pipe is upstream. A three-way switching valve for switching the second mode for communicating the side and the downstream side;
An absorption refrigerator vacuum holding device comprising: In the vacuum holding device of the absorption refrigerator according to claim 1,
A low-level liquid level sensor provided in the middle of the check valve bypass pipe for detecting a liquid level drop in the non-condensable gas tank;
When the low level liquid level sensor detects a drop in the liquid level, a control device that controls the discharge valve and the three-way switching valve to discharge the non-condensable gas in the non-condensable gas tank;
An absorption refrigerator vacuum holding device comprising: The vacuum holding device for an absorption refrigerator according to claim 2 is:
A high-level liquid level sensor for detecting an increase in the liquid level in the non-condensable gas tank, and the control device detects the discharge valve and the three-way switching valve when the high-level liquid level sensor detects an increase in the liquid level. The vacuum holding device for an absorption refrigeration machine, wherein the discharge operation of the non-condensable gas in the non-condensable gas tank is completed by controlling

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