JP3641763B2 - Solid corrosion inhibitor for absorption refrigerator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a solid corrosion inhibitor added to an absorption solution and an absorption refrigerator using the same in an absorption refrigerator having a circulation system of a refrigerant and an absorption solution.
[0002]
[Prior art]
As a corrosion inhibitor solid substance added to the absorption solution of the absorption refrigerator, for example, there is one disclosed in JP-A-6-221728. This corrosion inhibitor solid was prepared by mixing a first compound powder containing crystallization water and having a corrosion inhibitory effect with a second compound powder being a corrosion inhibitor, and making the mixture into a tablet by compression molding. Is. The first compound powder has at least one of lithium hydroxide, lithium chromate, cobalt chloride, and the like, and the second compound powder has at least one of lithium molybdate, lithium nitrate, lithium borate, and the like. It has one. In addition, the conventional absorption refrigerator is obtained by adding the above-mentioned corrosion inhibitor solid to the absorption solution in order to prevent corrosion inside the absorption refrigerator. This is because if the inside of the absorption refrigerator is corroded, a large amount of hydrogen gas is generated due to the corrosion reaction, the pressure in the absorption refrigerator is increased, and the refrigerating capacity is reduced. The addition of the solid substance of the corrosion inhibitor is performed at the same time as the absorption solution is charged at the factory shipment stage of the absorption refrigerator.
[0003]
[Problems to be solved by the invention]
However, since the conventional corrosion inhibitor solids become brittle and shattered in the absorption solution, there is a possibility that the fine powder of the corrosion inhibitor solids clogs the circulation system of the absorption solution. Then, the corrosion inhibitor solids in the absorption solution are consumed relatively quickly in proportion to the operation time of the absorption refrigerator and the corrosion inhibition effect is lost, and a large amount of hydrogen gas is generated by the corrosion reaction. , And the refrigeration capacity decreases in proportion to the operation time. In order to recover this decrease in refrigeration capacity, it was necessary to re-add the corrosion inhibitor solids to the absorbing solution.
[0004]
For this reason, it is necessary to add a corrosion inhibitor proactively in anticipation of when the corrosion inhibitor solids are consumed and the refrigeration capacity is reduced. The operation of the refrigerator had to be stopped once, and moreover, every time the corrosion inhibitor solids were consumed, a laborious operation had to be repeated.
[0005]
Furthermore, if the corrosion inhibitor solid is added at a high concentration in the initial stage such as the factory shipment stage in order to lengthen the re-addition period of the above-mentioned corrosion inhibitor solid, the optimum corrosion inhibition effect cannot be obtained, and vice versa. In some cases, corrosion may be accelerated, or the solubility of the absorption solution may not be able to cope with the dissolution of the corrosion inhibitor, and precipitates may be generated, obstructing the circulation of the absorption solution and hindering the operation of the absorption refrigerator. It was.
[0006]
The object of the present invention is to show a constant dissolution amount without embrittlement over a long period of time, maintain the circulation system of the absorption solution always well, and have no troubles such as shutdown of the absorption refrigerator, and easy to operate. It is to provide a solid corrosion inhibitor for an absorption refrigerator and an absorption refrigerator using the same.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the solid corrosion inhibitor for absorption refrigerator according to the present invention is obtained by kneading a first compound aqueous solution as a binder and a second compound powder as a corrosion inhibitor in a paste form. Heated and dried. A product obtained by kneading a first compound aqueous solution having a corrosion inhibitory effect and a second compound powder, which is a corrosion inhibitor, into a paste is heated and dried, so that a solid is easily formed. By using the material in the absorbent solution circulation system, it gradually dissolves without embrittlement over a long period of time, so it is possible to supplement the corrosion inhibitor consumed in the absorbent solution circulation system, and the absorption solution circulation. Keep the system always good.
[0008]
Further, in the solid corrosion inhibitor for absorption refrigerator, the first compound aqueous solution is a lithium bromide (LiBr) aqueous solution. In the case where the first compound aqueous solution is a lithium bromide aqueous solution, in addition to the action of the solid corrosion inhibitor for absorption refrigerators, the lithium bromide aqueous solution exhibits an appropriate binding force as a binder, and the solid matter becomes brittle. To prevent clogging due to powder spillage.
[0009]
In any one of the above-described corrosion inhibitor solids for an absorption refrigerator, the second compound powder is antimony trioxide (Sb ₂ O ₃ ). In the case where the second compound powder is diantimony trioxide, in addition to the action of any one of the above-described corrosion inhibitor solids for an absorption refrigerator, the corrosion of the circulating system of the absorption solution is surely suppressed.
[0010]
Further, the absorption refrigerator of the present invention is connected to a high-temperature regenerator, a separator, a low-temperature regenerator, a condenser, an evaporator, an absorber, a solution circulation pump, etc. to form a refrigerant and absorption solution circulation system, Corrosion inhibitor supply means having a container containing any one of the corrosion inhibitor solids for absorption refrigerators, the corrosion inhibitor supply means, a part of the absorption solution from the circulation system of the absorption solution to the container After the introduction, a part of the absorption solution is returned to the circulation system of the absorption solution. After the corrosion inhibitor supply means introduces a part of the absorption solution from the absorption system circulation system to the container, the part of the absorption solution is returned to the absorption solution circulation system without being embrittled for a long time. The corrosion inhibitor solids can be dissolved automatically so that the optimum concentration is always obtained, and the circulation system of the absorption solution is always maintained in good condition, and the absorption refrigerator is not shut down and corroded in the absorption refrigerator. And the capacity of the absorption refrigerator can be maintained over a long period of time.
[0011]
Furthermore, in the absorption refrigerator, the corrosion inhibitor supply means includes a flow rate adjusting unit that adjusts the flow rate of the absorbing solution introduced into the container. In the case where the corrosion inhibitor supply means has a flow rate adjusting unit for adjusting the flow rate of the absorbing solution introduced into the container, in addition to the action of the absorption refrigerator, the consumption of the corrosion inhibitor solids is always kept constant and absorbed. Maintain the corrosion inhibitor concentration in solution at the optimum value.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a solid corrosion inhibitor for an absorption refrigerator and an absorption refrigerator using the same according to the present invention will be described in detail with reference to the drawings.
[0013]
The solid corrosion inhibitor for absorption refrigerator according to the present embodiment is a solidified corrosion inhibitor, and includes a binder and a corrosion inhibitor. A paste prepared by kneading a first compound aqueous solution, which is a binder, and a second compound powder, which is a corrosion inhibitor, is heated and dried. Here, the first compound aqueous solution is preferably one having a corrosion inhibiting effect, and for example, a lithium bromide (LiBr) aqueous solution is preferable. The second compound powder is a corrosion inhibitor and, for example, diantimony trioxide is selected. The solid corrosion inhibitor for absorption refrigerator according to the present embodiment is a component of the absorption solution as a binder, and has a water-absorbing lithium bromide solution, and antimony trioxide as a corrosion inhibitor.
[0014]
As a solidification method, 5 g of diantimony trioxide and 15 g of a 60 wt% lithium bromide aqueous solution are mixed at a weight ratio of 1: 1 to 5 and kneaded into a paste. When this is put into a mold and heated at a temperature of 80 to 100 ° C. for 20 to 30 hours and dried, a solid corrosion inhibitor solid is formed. When the ratio of the aqueous lithium bromide solution is less than 1 with respect to diantimony trioxide, the mixture is difficult to form a paste. When the proportion of the aqueous lithium bromide solution exceeds 5 with respect to diantimony trioxide, it is easy to fluidize and it is difficult to form solids, and the amount of diantimony trioxide is small and the corrosion inhibiting effect is small for the volume of solids. Become. When the heating temperature is less than 80 ° C., the drying speed is slow and takes time. When the heating temperature exceeds 150 ° C., the boiling point of this mixture is approximately 150 ° C., so that boiling occurs and a solid solid cannot be obtained. FIG. 2 is a block diagram showing a dissolution test apparatus for measuring the dissolution characteristics of the corrosion inhibitor solids. In this dissolution test apparatus 2, the solution tank 3 with the flange 4 is filled with the solution 8, and the lid 5 is fixed and sealed with appropriate fastening means, and then the vacuum pulling tube 6 and the valve 7 provided on the lid 5. Thus, the inside of the solution tank 3 is evacuated . Further, in the above solution, the corrosion inhibitor solid material 1 of the present embodiment is placed at the bottom of the solution tank 3. The solution 8 is a lithium bromide (LiBr) aqueous solution (200 ml of a concentration of 60 wt% (LiOH 0.12 normal)), and the above-described corrosion inhibitor solids of the present embodiment ( Antimony trioxide and lithium bromide aqueous solution) or prior art corrosion inhibitor solids (antimony trioxide and cobalt chloride hexahydrate) are submerged.
[0015]
Then, the temperature of the solution 8 was set at two levels of 70 ° C. and 160 ° C., and the concentrations of antimony trioxide in the supernatant liquid with the passage of time were measured and compared. Here, the corrosion inhibitor solid of the present embodiment is formed by the above-described method, but the corrosion inhibitor solid of the prior art uses 5 g of antimony trioxide and 10 g of binder as a binder. Cobalt chloride hexahydrate was used and formed at a molding compression pressure of 500 kgf / cm ² , and the dimensions were compression formed into a cylinder of φ30 mm × 15 mm.
[0016]
FIG. 1 is a curve diagram showing the dissolution characteristics of the corrosion inhibitor solid according to the present embodiment and the corrosion inhibitor solid according to the prior art by the dissolution test apparatus 2 shown in FIG. The elapsed time (h) is plotted on the horizontal axis, and the concentration of diantimony trioxide (mg / l) in the solution is plotted on the vertical axis. Curve 31 (circle) indicates the case of the solid corrosion inhibitor of the present embodiment at the test temperature of 160 ° C. Curve 32 (Δ) indicates the case of the solid corrosion inhibitor of the prior art at the test temperature of 160 ° C. Further, each curve 33 (circle) indicates the corrosion inhibitor solid of the present embodiment at the test temperature of 70 ° C., and curve 34 (Δ) indicates the conventional corrosion inhibitor solid at the test temperature of 70 ° C. In the case of a thing, each is shown.
[0017]
The amount of dissolution of the corrosion inhibitor solid at 70 ° C. is almost the same between the curve 33 of the present embodiment and the curve 34 of the prior art. However, at 160 ° C., the curve 32 of the prior art has a remarkably fast dissolution rate, whereas the curve 31 using the solid corrosion inhibitor of the present embodiment has a substantially constant dissolution amount over a long period of time. Is shown.
[0018]
Furthermore, both of the conventional corrosion inhibitor solids (curves 32 and 34) became brittle and shattered in tens of hours, whereas the corrosion inhibitor solids of the present embodiment (curves 31 and 33). Was gradually dissolved from around the solid matter and did not become brittle even after 1000 hours.
[0019]
FIG. 3 is a system diagram of an embodiment of an absorption refrigerator according to the present invention. The absorption refrigerator 10 of the present embodiment is connected to a high temperature regenerator 11, a separator 13, a low temperature regenerator 14, a condenser 15, an evaporator 16, an absorber 17, a solution circulation pump 19, and two solution control valves 20. Then, a corrosion inhibitor supply means 21 having a container 24, 25 or 26 in which the refrigerant and absorbent solution circulation system is formed and containing the corrosion inhibitor solid material 1 for the absorption refrigerator of the present embodiment described above, 22 or 23 is provided. The corrosion inhibitor supply means 21, 22 or 23 is for gradually dissolving the corrosion inhibitor solid 1 into the solution, and the corrosion inhibitor supply means 21, 22 or 23 may be provided independently, They may be used in combination.
[0020]
Here, the high temperature regenerator 11 is made of LiBr or the like sent via the solution control valve 20 and heats a dilute solution containing a corrosion inhibitor. The separator 13 evaporates the moisture of the diluted solution heated by the high-temperature regenerator 11, separates the vapor and the absorbing solution, and thickens the absorbing solution to an intermediate concentration. The low temperature regenerator 14 further concentrates the intermediate concentration solution supplied from the separator 13 with steam supplied from the separator 13 to form a concentrated solution. The condenser 15 condenses the vapor supplied from the low temperature regenerator 14 into water that is a liquid refrigerant. The evaporator 16 evaporates the liquid refrigerant sent from the condenser 15 and cools a cooling water pipe (not shown) with the latent heat of evaporation. The absorber 17 absorbs the vapor evaporated in the evaporator 16 in the concentrated solution sent from the low temperature regenerator 14. The solution circulation pump 19 is a pump for circulating the absorption solution. The solution control valve 20 is a valve that controls the circulation flow rate of the absorbing solution.
[0021]
FIG. 4 is an enlarged view of a main part showing the corrosion inhibitor supply means 21 provided on the inlet side of the high temperature regenerator 11 of FIG. The corrosion inhibitor supply means 21 is provided in parallel to the pipe 12 for sending the dilute solution to the high temperature regenerator 11 in a bypass manner, and introduces a part of the dilute solution through the introduction pipe 27 to the inside of the container 24. After the corrosion inhibitor solid material 1 placed in the is dissolved, it is returned through the return pipe 28. Further, the corrosion inhibitor supply means 21 has a control valve 29 and a closing valve 30 which are flow rate adjusting parts for adjusting the flow rate of the absorbing solution introduced into the container 24. The control valve 29 and the closing valve 30 may be interchanged. The corrosion inhibitor supply means 22 in FIG. 3 has the same structure as the corrosion inhibitor supply means 21.
[0022]
FIG. 5 is a schematic diagram showing the structure of the corrosion inhibitor supply means 23 having the container 26 shown in FIG. The corrosion inhibitor supply means 23 includes a container 26 having a water tank shape as shown in FIG. 5 and is provided below the absorber 17. The container 26 is open at the top of the container 26 in order to receive the absorbing solution dripping from the absorber cooling water coil 18. A corrosion inhibitor solid 1 is placed in the container 26.
[0023]
Next, operation | movement of the absorption refrigerator of this Embodiment is demonstrated. First, the operation of the corrosion inhibitor supply means 21 shown in FIG. 4 will be described. The corrosion inhibitor supply means 21 introduces an absorbing solution having an appropriate flow rate into the container 24 and discharges the absorbing solution having a flow rate corresponding to the introduced flow rate to the high temperature regenerator 11. Thereby, the corrosion inhibitor solid 1 is dissolved in the absorption solution in the container 24, and the corrosion inhibitor is added to the circulation system of the absorption refrigerator. Here, the absorption solution flow rate introduced by the corrosion inhibitor supply means 21 is adjusted and set according to the temperature of the absorption solution, the dissolving power of the corrosion inhibitor solid material 1 and the like.
[0024]
Since the corrosion inhibitor supply means 21 shown in FIG. 4 introduces a relatively high-temperature absorption solution downstream of the high-temperature regenerator 11, the corrosion inhibitor solid material 1 that does not dissolve too much even at a relatively high temperature is used. Are suitable. On the other hand, the corrosion inhibitor supply means 22 is provided on the concentrated solution outlet side of the low-temperature regenerator and introduces an absorption solution having a temperature lower than that of the corrosion inhibitor supply means 21, so that the corrosion inhibitor solids that are easily dissolved even at a relatively low temperature. It is suitable for using the object 1.
[0025]
Next, the operation of the corrosion inhibitor supply means 23 shown in FIG. 5 will be described. The container 26 of the corrosion inhibitor supply means 23 receives the absorbing solution dripping from the absorber cooling water coil 18 and overflows the absorbing solution having a flow rate corresponding to the received amount toward the solution circulation pump 19 (not shown). Let it come out. Thereby, the corrosion inhibitor solid 1 is dissolved in the absorption solution in the container 26, and the corrosion inhibitor is added to the circulating absorption solution of the absorption refrigerator. Here, the absorption solution flow rate received by the container 26 can be adjusted by adjusting the open area of the upper part of the container 26.
[0026]
Furthermore, since the corrosion inhibitor supply means 23 introduces an absorption solution at a lower temperature than the corrosion inhibitor supply means 22 due to the installation position, it is easier to dissolve at a lower temperature than the corrosion inhibitor solids placed in the container 25. Suitable for using corrosion inhibitor solids 1.
[0027]
By providing the corrosion inhibitor supply means 23 in the absorber 17, the absorption refrigerator 10 of the present embodiment automatically compensates for the corrosion inhibitor consumed in the circulation system of the absorption solution by a long-term operation, Since the concentration of the corrosion inhibitor in the circulation system can be kept almost constant over a long period of time, corrosion in the absorption refrigerator main body can be suppressed and the life of the absorption refrigerator can be extended. Furthermore, the absorption refrigerator 10 can reduce the number of times of maintenance for restoring or maintaining the capacity.
[0028]
As described above, according to the absorption refrigerator of the present embodiment, the most suitable corrosion suppression is performed according to the relationship between the required amount of corrosion inhibitor replenishment and the dissolving power and corrosion inhibiting power of the corrosion inhibitor used. By providing the solid agent at a position where the absorbent solution circulation system is at an appropriate temperature, it can be replenished after the operation of the absorption refrigerator. Since the corrosion inhibitor solid material 1 of the present embodiment is gradually dissolved in the absorption solution over a long period of time, it can supplement the corrosion inhibitor consumed in the circulation system of the absorption solution. Life can be extended.
[0029]
【The invention's effect】
According to the solid corrosion inhibitor for absorption refrigerator of the present invention, since it gradually dissolves in the absorption solution over a long period of time, it can supplement the corrosion inhibitor consumed in the circulation system of the absorption solution and absorb Maintain a good circulation system of the solution at all times.
[0030]
In addition, according to the absorption refrigerator of the present invention, since the corrosion inhibitor solids are automatically added to the circulation system of the absorption solution, the absorption refrigerator is capable of suppressing corrosion in the absorption refrigerator for a long period of time. Is easy to drive.
[Brief description of the drawings]
FIG. 1 is a curve diagram showing the dissolution characteristics of an embodiment of a corrosion inhibitor solid for an absorption refrigerator according to the present invention together with the corrosion inhibitor solid for an absorption refrigerator according to the prior art.
FIG. 2 is a cross-sectional view of a dissolution test apparatus for measuring the dissolution characteristics of a corrosion inhibitor solid.
FIG. 3 is a system diagram of an absorption refrigerator according to the present invention.
4 is an enlarged view of a main part showing a corrosion inhibitor supply means provided on the high temperature regenerator inlet side of FIG. 3;
FIG. 5 is an enlarged view of a main part showing a corrosion inhibitor supply means provided in the absorber of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Corrosion inhibitor solid substance 10 Absorption freezer 11 High temperature regenerator 13 Separator 14 Low temperature regenerator 15 Condenser 16 Evaporator 17 Absorber 19 Solution circulation pump 21, 22, 23 Corrosion inhibitor supply means 24, 25, 26 Container 29 Control valve (flow rate adjuster)
30 Shut-off valve (flow rate adjuster)

Claims (5)

A solid corrosion inhibitor for an absorption refrigeration machine, which is obtained by heating and drying a paste prepared by kneading a first compound aqueous solution as a binder and a second compound powder as a corrosion inhibitor. . 2. The corrosion inhibitor solid for absorption refrigerators according to claim 1, wherein the first compound aqueous solution is a lithium bromide aqueous solution. 3. The corrosion inhibitor solid for absorption refrigerator according to claim 1, wherein the second compound powder is antimony trioxide. The absorption refrigerator according to any one of claims 1 to 3, wherein a high-temperature regenerator, a separator, a low-temperature regenerator, a condenser, an evaporator, an absorber, a solution circulation pump, and the like are connected to form a refrigerant and absorption solution circulation system. A corrosion inhibitor supply means having a container containing a solid substance for a corrosion inhibitor for absorption refrigerators, wherein the corrosion inhibitor supply means removes a part of the absorption solution from the circulation system of the absorption solution to the container. An absorption refrigerator, wherein a part of the absorption solution is returned to the circulation system of the absorption solution after being introduced into the system. 5. The absorption refrigerator according to claim 4, wherein the corrosion inhibitor supply means includes a flow rate adjusting unit that adjusts the flow rate of the absorbing solution introduced into the container.

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