JP2835805B2 - Absorption refrigerator and corrosion inhibitor solids for absorption refrigerator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion inhibitor to be added to a solution for transferring heat in an absorption refrigerator (hereinafter, simply referred to as a solution), and a method for controlling the concentration of the corrosion inhibitor in the solution. Related to a device that keeps constant.

[0002]

2. Description of the Related Art In a conventional absorption refrigerator, a corrosion inhibitor is added to a solution in order to prevent corrosion inside the absorption refrigerator. This is because when the inside of the absorption refrigerator is corroded, a large amount of hydrogen gas is generated by the corrosion reaction, the pressure inside the absorption refrigerator increases, and the refrigeration capacity decreases. Then, the addition of the corrosion inhibitor is performed at the same time as the introduction of the solution at the factory shipping stage of the absorption refrigerator. As the corrosion inhibitor, lithium chromate, lithium molybdate, and lithium nitrate are mainly used.

[0003]

However, in the conventional absorption refrigerator described above, the corrosion inhibitor in the solution is consumed in proportion to the operation time of the absorption refrigerator, and the corrosion inhibiting effect is reduced. The refrigeration capacity decreases in proportion to the operation time. In order to recover this decrease in refrigeration capacity,
It is necessary to re-add the corrosion inhibitor to the solution. In addition, anticipating when the corrosion inhibitor will be consumed and the refrigeration capacity will decrease,
It is necessary to preventively add a corrosion inhibitor. In addition, in the conventional absorption refrigerator, the operation of the absorption refrigerator must be temporarily stopped in order to re-add the corrosion inhibitor, and a time-consuming operation is repeatedly performed every time the corrosion inhibitor is consumed. I had to.

On the other hand, if the corrosion inhibitor is added at a high concentration at an initial stage such as a factory shipment stage in order to lengthen the period of re-addition of the above-mentioned corrosion inhibitor, an optimum corrosion inhibitory effect cannot be obtained.
Conversely, corrosion is promoted, or the solubility of the solution cannot correspond to the dissolution of the corrosion inhibitor, and precipitates are generated to hinder circulation of the solution, which hinders the operation of the absorption refrigerator.

The present invention provides a method for automatically adding a corrosion inhibitor solid to an absorption refrigerator capable of maintaining the concentration of the corrosion inhibitor in a solution of the absorption refrigerator constant, and automatically adding the corrosion inhibitor to a solution circulation system. And to provide an absorption refrigerator.

[0006]

The solid corrosion inhibitor for an absorption refrigerator according to the present invention comprises a first compound powder containing water of crystallization and having a corrosion inhibitory effect, and a second compound powder as a corrosion inhibitor. Are mixed, and the resulting mixture is compression-molded into tablets.

[0007] The solid substance of the corrosion inhibitor for an absorption refrigerator according to the present invention is characterized in that the first compound powder comprises lithium hydroxide (monohydrate), lithium chromate (dihydrate), and cobalt chloride. (Hexahydrate) and cupric chloride (dihydrate).

[0008] In addition, the solid corrosion inhibitor for an absorption refrigerator of the present invention, wherein the second compound powder is lithium molybdate, lithium nitrate, lithium borate, lithium tungstate, lithium phosphate, And at least one of antimony trioxide.

[0009] The absorption refrigerator of the present invention comprises: an introduction part for introducing a part of the solution from a circulation system of the solution for transferring heat;
A tank portion for temporarily storing the introduced solution, and a discharge portion for returning the solution from the tank portion to the solution circulation system,
It is characterized by having a corrosion inhibitor feeder which incorporates a solid formed by compressing and solidifying a corrosion inhibitor into the tank portion.

Further, the absorption refrigerator according to the present invention is characterized in that the solid substance contained in the tank portion is a corrosion inhibitor solid substance for the absorption refrigerator.

Further, in the absorption refrigerator of the present invention,
It is characterized by having a flow rate adjusting unit for adjusting the flow rate of the solution to be introduced.

[0012]

In the absorption refrigerator according to the present invention, the corrosion inhibitor solid is placed in a solution circulation system such as a corrosion inhibitor feeder before starting operation. Then, the solid corrosion inhibitor gradually dissolves in the solution in the solution circulation system over a long period of time to supplement the corrosion inhibitor consumed in the solution circulation system. Thereby, the concentration of the corrosion inhibitor in the solution of the absorption refrigerator is kept near a certain optimum value over a long period of time.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment is a corrosion inhibitor solid obtained by solidifying a corrosion inhibitor. The corrosion inhibitor solid includes a binder containing water of crystallization that can serve as a binder for forming the solid and having a corrosion inhibitory effect, and a corrosion inhibitor.

The binder is selected from lithium hydroxide (monohydrate), lithium chromate (dihydrate), cobalt chloride (hexahydrate), cupric chloride (dihydrate) and the like. Use at least one. As the corrosion inhibitor, at least one of lithium molybdate, lithium nitrate, lithium borate, lithium tungstate, lithium phosphate, antimony trioxide and the like is used.

The binder powder composed of the above-mentioned components and the corrosion inhibitor powder are sufficiently mixed, and the mixed powder is subjected to compression molding to obtain a solid corrosion inhibitor as a tablet.
When the mixed powder of the binder and the corrosion inhibitor is compressed, water of crystallization is released from the binder, and moderate humidity is applied to the entire mixed powder to form a strong solid.

Next, the characteristics of the corrosion inhibitor solid according to the present embodiment will be described. FIG. 1 is a graph showing the dissolution characteristics of the solid corrosion inhibitor according to the present embodiment. FIG. 2 is a graph showing the dissolution characteristics of another solid corrosion inhibitor according to the present embodiment. FIG. 3 is a block diagram showing a dissolution test apparatus for measuring the dissolution characteristics of the corrosion inhibitor solid according to the present embodiment.

The dissolution test device shown in FIG. 3 is a device for measuring the dissolution characteristics of the corrosion inhibitor solid, and the dissolution characteristics of the corrosion inhibitor solid shown in FIGS. 1 and 2 are measured using this device. It was measured. The dissolution test apparatus includes a solid object installation container 31,
It comprises a solution tank 32, a solution circulation pump 33, a regenerator 34, an electric heater 35, an electromagnetic flow meter 36, a pipe 37, a pipe 38, a flow control valve 39 and a flow control valve 40.

Further, the dissolution test device is provided as a circulating solution,
20 liters of LiBr having a concentration of 60 wt% (LiOH
0.12). In the circulating solution, the same amount of corrosion inhibitor as the corrosion inhibitor solid as the test object was dissolved beforehand before the test. And the circulating solution has a temperature of 120
° C and the circulation flow rate is 1400 (l / hr)
The tube 38 was set to 10 (l / hr).

The concentration of the corrosion inhibitor in the circulating solution was measured using the dissolution test apparatus configured as described above, with and without the corrosion inhibitor solid 30 installed in the solid installation container 31, and the corrosion inhibitor concentration was measured. The effect of the inhibitor solid 30 was confirmed. 1 and 2 are graphs showing the test results of the corrosion inhibitor solid 30 by the dissolution test apparatus shown in FIG. 3, and the effect of the corrosion inhibitor solid 30 appears.

FIG. 1 shows a molding compression pressure of 500 kg / cm 2 using 10 g of antimony trioxide as a corrosion inhibitor and 20 g of cobalt chloride (hexahydrate) as a binder.
² is a test result of the corrosion inhibitor solid 30 formed in ² .
This corrosion inhibitor solid 30 has a size of φ30 mm × 15.
mm.

In FIG. 1, the curve of “with Sb solids” indicates that the above-mentioned corrosion inhibitor solids 30 are mixed with the solids installation container 31.
2 shows the concentration of antimony trioxide in the circulating solution at each test time when the sample was installed in the test sample. The curve of “Co solids present” indicates that the above-described corrosion inhibitor solids 30 were added to the solids installation container 31.
2 shows the concentration of cobalt chloride in the circulating solution at each test time when the sample was installed in the test sample. On the other hand, the curve of “No Sb solid” shows the antimony trioxide concentration of the circulating solution at each test time when the corrosion inhibitor solid 30 was not installed in the solid installation container 31. The curve of “No Co solid” indicates the concentration of cobalt chloride in the circulating solution at each test time when the corrosion inhibitor solid 30 was not installed in the solid installation container 31.

From these curves, it can be seen that the corrosion inhibitor solid 30
It can be seen that the rate of decrease in the concentration of the corrosion inhibitor with respect to the elapse of the test time is significantly smaller in the case where is installed in the solid matter installation container 31 than in the case where it is not installed.

FIG. 2 shows a molding compression pressure of 750 K using 6 g of lithium molybdate as a corrosion inhibitor and 24 g of lithium chromate (dihydrate) as a binder.
5 is a test result of the corrosion inhibitor solid 30 formed at g / cm ² . The size of the corrosion inhibitor solid 30 is φ30 mm.
It was compression-formed into a cylindrical shape of × 15 mm.

In FIG. 2, the curve “Mo solids present” indicates that the above-mentioned corrosion inhibitor solids 30 are connected to the solid installation container 31.
Shows the concentration of lithium molybdate in the circulating solution at each test time when the sample is installed in the test sample. The curve “Cr solids present” indicates the lithium chromate concentration of the circulating solution at each test time when the above-described corrosion inhibitor solids 30 were installed in the solids installation container 31. On the other hand, the curve of “No Mo solid” shows the concentration of lithium molybdate in the circulating solution at each test time when the corrosion inhibitor solid 30 was not installed in the solid installation container 31. The curve of “No Cr solid” shows the lithium chromate concentration of the circulating solution at each test time when the corrosion inhibitor solid 30 was not installed in the solid installation container 31.

From these curves, it can be seen that the corrosion inhibitor solid 30
It can be seen that the rate of decrease in the concentration of the corrosion inhibitor with respect to the elapse of the test time is significantly smaller in the case where is installed in the solid matter installation container 31 than in the case where it is not installed. In the case of “Mo solids present”, the initial concentration is 2000
Since the time is maintained for more than the time, it is understood that if the optimum concentration is set in the initial stage, the concentration can be maintained for a long period of time.

As a result, the corrosion inhibitor solid of the present embodiment is not completely dissolved in the solution at the start of the operation of the absorption refrigerator, or the corrosion inhibitor, which has no effect even if dissolved, is dissolved in the solution of the absorption refrigerator. It can be kept in the circulation. And since the corrosion inhibitor solids gradually dissolve in the solution over a long period of time, the corrosion inhibitor exhausted in the solution circulation system can be supplemented, and the equipment life of the absorption refrigerator can be extended. .

The second embodiment is an absorption refrigerator having a corrosion inhibitor supplying device for supplying a corrosion inhibitor in the solution circulation system of the absorption refrigerator. FIG. 4 is a block diagram illustrating an absorption refrigerator according to a second embodiment. The absorption refrigerator shown in FIG. 4 includes a corrosion inhibitor supply unit 41, 45, 48, a high temperature regenerator 42, a separator 43, a low temperature regenerator 44, a condenser 46, an absorber 47, and an evaporator 49. , A solution circulation pump 50 and a solution control valve 51.

The corrosion inhibitor feeders 41, 45, and 48 are devices for gradually dissolving the corrosion inhibitor solids, which are formed by compressing and solidifying the corrosion inhibitor, into the solution. The corrosion inhibitor solid is the corrosion inhibitor solid according to the first embodiment. The high-temperature regenerator 42 includes the solution control valve 5
1 is for heating a dilute solution made of LiBr or the like and passed through 1 and containing a corrosion inhibitor. Separator 43
Is to evaporate the moisture of the dilute solution heated by the high-temperature regenerator 42 and separate the vapor from the solution to thicken the solution to an intermediate concentration. The low-temperature regenerator 44 includes a separator 43.
The intermediate concentration solution supplied from the separator 43 is further concentrated by the vapor supplied from the separator 43 into a concentrated solution.
The condenser 46 condenses the steam supplied from the low-temperature regenerator 44 into water. The evaporator 49 evaporates water, which is a refrigerant sent from the condenser 46, and cools a chilled water pipe (not shown) with the latent heat of evaporation. Absorber 47
Is for absorbing the vapor evaporated in the evaporator 49 into the concentrated solution sent from the low-temperature regenerator 44. The solution circulation pump 50 is a pump for circulating the solution. The solution control valve 51 is a valve that controls the circulation flow rate of the solution.

FIG. 5 shows the corrosion inhibitor supply device 41 shown in FIG.
It is a schematic diagram showing the structure of. The corrosion inhibitor supply device 41 includes:
The bypass pipe is connected in parallel to a pipe for sending the solution to the high temperature regenerator 42, and introduces and discharges a part of the solution. In the corrosion inhibitor feeder 41, a corrosion inhibitor solid 52 is placed. Further, the corrosion inhibitor supply unit 45 has the same structure as the corrosion inhibitor supply unit 41, and is provided on a pipe for sending a concentrated solution from the low-temperature regenerator 44 to the absorber 47.

FIG. 6 shows the corrosion inhibitor supply unit 48 shown in FIG.
It is a schematic diagram showing the structure of. Corrosion inhibitor supply 48
This is a container having a water tank shape as shown in FIG. 6 and is provided below the absorber 47. The corrosion inhibitor supply 48 is then open at the top of the container to introduce the solution dripping from the absorber coil. Further, in the corrosion inhibitor supply device 48, a corrosion inhibitor solid 61 is placed.

Next, the operation of this embodiment will be described.
First, the operation of the corrosion inhibitor supply device 41 shown in FIG. 5 will be described. The corrosion inhibitor supply device 41 introduces an appropriate flow rate of the solution into the inside, and discharges the solution at a flow rate corresponding to the introduced flow rate toward the high-temperature regenerator 42. As a result, the corrosion inhibitor solids 52 dissolve into the solution in the corrosion inhibitor feeder 41, and the corrosion inhibitor is added to the circulating solution of the absorption refrigerator. Here, the flow rate of the solution introduced by the corrosion inhibitor feeder 41 is adjusted and set according to the temperature of the solution, the dissolving power of the corrosion inhibitor solid 52, and the like.

Further, since the corrosion inhibitor feeder 41 introduces a solution having a relatively high temperature depending on the installation position, the corrosion inhibitor solid which is not easily dissolved unless the temperature is relatively high is used as the corrosion inhibitor solid 52. Suitable for use.

On the other hand, since the corrosion inhibitor supplier 45 introduces a solution at a lower temperature than the corrosion inhibitor supplier 41 due to the installation position, it is necessary to use a corrosion inhibitor solid which is easily dissolved even at a relatively low temperature. Are suitable.

Next, the operation of the corrosion inhibitor supply unit 48 shown in FIG. 6 will be described. The corrosion inhibitor supply device 48 receives the solution dripping from the absorber coil, and overflows the solution at a flow rate corresponding to the received amount toward the solution circulation pump 50. As a result, the corrosion inhibitor solids 61 dissolve into the solution in the corrosion inhibitor feeder 48, and the corrosion inhibitor is added to the circulating solution of the absorption refrigerator. Here, the flow rate of the solution received by the corrosion inhibitor supply unit 48 can be adjusted by adjusting the open area of the upper part of the container of the corrosion inhibitor supply unit 48.

Since the corrosion inhibitor feeder 48 introduces a solution at a lower temperature than the corrosion inhibitor feeder 45 due to the installation position, the corrosion inhibitor feeder 48 removes the solid solution contained in the corrosion inhibitor feeder 45. It is also suitable to use a corrosion inhibitor solid that is easily dissolved at a low temperature as the corrosion inhibitor solid 61.

Thus, the absorption refrigerator of this embodiment is
The corrosion inhibitor consumed in the solution circulation system over a long period of operation is automatically compensated for, and the concentration of the corrosion inhibitor in the solution circulation system can be kept almost constant for a long period of time. Corrosion in the main body of the machine can be suppressed, and the life of the absorption refrigerator can be extended. In addition, the absorption refrigerator of the present embodiment can reduce the number of maintenance calls for recovering or maintaining the capacity.

It is to be noted that the solution of the corrosion inhibitor is appropriately selected depending on the amount of the corrosion inhibitor to be supplied in the absorption refrigerator and the dissolving power and corrosion inhibiting power of the solid corrosion inhibitor used. It can be installed at a position in the solution circulation system that is at a temperature.

[0039]

As described above, according to the present invention, the corrosion inhibitor solid gradually dissolves in the solution over a long period of time, so that the corrosion inhibitor exhausted in the solution circulation system is supplemented. Can be. In addition, the corrosion inhibitor supply device can hold the corrosion inhibitor in the solution circulation system of the absorption refrigerator and automatically add the corrosion inhibitor to the solution circulation system. With these, the present invention can maintain the corrosion inhibitor concentration in the solution circulation system in the absorption refrigerator at an optimum value over a long period of time, so that corrosion in the absorption refrigerator over a long period can be suppressed. The capacity of the absorption refrigerator can be maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a graph showing the dissolution characteristics of a solid corrosion inhibitor according to a first embodiment of the present invention.

FIG. 2 is a graph showing the dissolution characteristics of another solid corrosion inhibitor according to the first embodiment of the present invention.

FIG. 3 is a block diagram showing a dissolution test apparatus for measuring the dissolution characteristics of a corrosion inhibitor solid.

FIG. 4 is a block diagram showing an absorption refrigerator according to a second embodiment of the present invention.

FIG. 5 is a schematic view showing the structure of a corrosion inhibitor supplier 41 in FIG.

FIG. 6 is a schematic diagram showing the structure of a corrosion inhibitor supplier 48 in FIG.

[Explanation of symbols]

 30, 52, 61 Corrosion inhibitor solids 41, 45, 48 Corrosion inhibitor supply unit 42 High temperature regenerator 43 Separator 44 Low temperature regenerator 46 Condenser 47 Absorber 49 Evaporator 50 Solution circulation pump 51 Solution control valve

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) F25B 47/00 C01D 15/00

Claims (4)

(57) [Claims] 1. A first material containing water of crystallization and having a corrosion inhibiting effect.
A solid corrosion inhibitor for absorption refrigerators, characterized in that the compound powder of (1) and a second compound powder as a corrosion inhibitor are mixed, and the mixture is compression-molded into tablets. 2. The corrosion inhibitor solid for absorption chillers according to claim 1, wherein the first compound powder comprises lithium hydroxide (monohydrate) and lithium chromate (dihydrate). ,
Cobalt chloride (hexahydrate) and cupric chloride (dihydrate)
A corrosion inhibitor solid for an absorption refrigerator comprising at least one of the following. 3. The solid of the corrosion inhibitor for an absorption refrigerator according to claim 1, wherein the second compound powder comprises lithium molybdate, lithium borate, lithium tungstate, lithium phosphate, A solid corrosion inhibitor for an absorption refrigerator comprising at least one of antimony oxide. 4. An introduction section for introducing a part of the solution from a circulating system of a solution for transferring heat, a tank section for temporarily storing the introduced solution, and a tank section for temporarily storing the introduced solution. In an absorption refrigerator having a discharge part for returning a solution and a corrosion inhibitor container containing a solid formed by compression-forming a corrosion inhibitor and solidifying in the tank part , the introduction part introduces
An absorption refrigerator comprising a flow rate adjusting section for adjusting a flow rate of a solution .