JPH1030859A - Absorption type heat pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize fluctuations in a vapor-liquid contact area even when the flow rate of an absorption liquid is subjected to fluctuations by constituting a flow-down surface of the absorption liquid which carries out a fractionating action in contact with vapor liquid contact while flowing down in a rectifier with a mesh surface having a capillary effect. SOLUTION: In a regenerator 31, the liquid condensed on the outside surface of a partial condenser 42 drops therefrom and is collected in a liquid dispersion device 41D laid out below the partial condenser 42. The liquid collected together at the liquid dispersion device 41D soaks into a metal net plate 41F inserted into an opening on the bottom of the liquid dispersion device 41D and spreads over the whole body of the metal net plate 41F by the effect of a capillary tube and drops. Due to this phenomenon, both surfaces of the metal net plate 41F are turned in a drenched state with an absorption liquid. Even when the flow rate of the absorption liquid is reduced, the contact area of vapor and liquid can be maintained at a larger value compared with the reduction in the flow rate. It is, therefore, possible to widen the flow rate range capable of maintaining a definite vapor liquid contact area even when the amount of rising vapor is changed and provide a stable rectification effect.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption heat pump using water-ammonia as a working medium, and more particularly to a rectifier used for removing water contained in generated ammonia vapor and increasing the concentration of refrigerant. The present invention relates to an absorption heat pump that takes into account the improvement of the efficiency of the heat pump.

[0002]

2. Description of the Related Art FIG. 6 shows the structure of a general absorption heat pump using water-ammonia as a working medium (absorbing liquid). The illustrated absorption heat pump includes a regenerator unit 31 for separating an absorption liquid (strong solution) into a refrigerant vapor and a weak solution, a condenser 32 for condensing and liquefying the refrigerant vapor separated by the regeneration unit 31, and the condenser An evaporator 35 that introduces the liquid refrigerant 46 generated at 32 through a refrigerant heat exchanger 33 and an expansion valve 34 and evaporates by heat exchange with a heat medium;
And an absorption unit 36 for introducing the refrigerant vapor evaporated in 5 through the refrigerant heat exchanger 33 and absorbing the refrigerant vapor into a weak solution.

The regenerator unit 31 of the absorption heat pump
Is a decomposing device 42, a rectifying device 41 arranged in order from the top,
The weak solution heat exchanger 40 and the regenerative heat input device 39 are configured to include the regenerator unit container 38 in which the weak solution heat exchanger 40 and the regenerative heat input device 39 are provided.
8 is connected to the bottom. The condenser 32 is a tube-body type having a heat exchanger 45 forming a cooling fluid flow path as a tube side flow path and a refrigerant flow path as a body side flow path. It is connected to the upper end of the body-side flow path of the vessel 32.

[0004] The absorption unit 36 is configured to include an absorption liquid dispersing device 51, an absorption heat recovery heat exchange unit 52, an absorption heat radiation unit 53 arranged in order from the top, and an absorption unit container 50 in which these are housed. The bottom of the absorption unit container 50 is connected to the upper end (input side) of the decomposer 42 via the solution circulation pump 37. The outlet side of the solution circulation pump 37 is connected to the upper end (inlet side) of the separator 42, and the suction side of the solution circulation pump 37 is connected to the bottom of the absorption unit container 50. The upper end (outside) of the absorption heat recovery heat exchange section 52 is connected to the middle position of the rectifier 41 of the regenerator unit container 38, and the lower end (entrance side) of the absorption heat recovery heat exchange section 52 is provided.
Is connected to the lower end (outside) of the decompressor 42. Further, a pressure reducing valve 57 is connected to the upper end (outlet side) of the weak solution heat exchanger 40 of the regenerator unit 31, and the outlet side of the pressure reducing valve 57 is connected to the absorbent dispersion device 51.

[0005] The evaporator 35 is a tube-body type having a heat exchanger 48 forming a heat medium flow path as a tube side flow path and a refrigerant flow path as a body side flow path.
The lower end (outside) of the body-side flow path of the condenser 32 is connected to the heating fluid flow path of the refrigerant heat exchanger 33 and the expansion-valve 34, and is provided at the top of the body-side flow path of the evaporator 35. 47. The body side flow path of the evaporator 35 is connected to the absorption unit container 5 via the heated fluid flow path of the refrigerant heat exchanger 33.
0 is connected to the lower part.

[0006] The regenerator unit 31 includes a solution circulating pump 3
7 is separated into a refrigerant vapor and a weak solution (a solution having a low refrigerant concentration) 55 having a high refrigerant concentration and supplied through a decomposer 42 and an absorption heat recovery heat exchange section 52. The weak solution is sent out to the body side flow path of the condenser 32 and the weak solution is sent out to the weak solution heat exchanger 40 in which the weak solution is housed.

[0007] The condenser 32 cools and condenses the refrigerant vapor sent from the regenerator unit 31 into the body side flow path with the heat medium passed through the tube side flow path (heat exchanger 45) to form a liquid refrigerant. . The generated liquid refrigerant passes through the heating fluid flow path of the refrigerant heat exchanger 33 and the expansion valve 34, is guided to the refrigerant dispersion device 47 provided in the evaporator 35, and drops on the outer surface of the heat transfer wall of the heat exchanger 48. Is done. The liquid refrigerant dropped on the outer surface of the heat transfer wall of the heat exchanger 48 removes heat of the heat medium flowing in the heat exchanger 48 and evaporates. The evaporated refrigerant vapor is introduced into the bottom of the absorption unit container 50 via the fluid passage to be heated of the refrigerant heat exchanger 33.

The absorption liquid (strong solution) 43 a stored at the bottom of the absorption unit container 50 is pressurized by the solution circulating pump 37, is heated through the decompressor 42 of the regenerator unit 31, and is further absorbed by the absorption unit 36. Heat recovery heat exchange section 52
Is introduced into the heat exchange channel from the lower inlet of the heat exchanger. The absorption liquid (strong solution) 55 that has passed through the absorption heat recovery heat exchange section 52 is introduced into the middle stage of the rectifier 41 of the regenerator unit 31. The absorption liquid (strong solution) introduced into the middle stage of the rectifier 41 of the regenerator unit 31 is separated into refrigerant vapor and a weak solution by the regeneration processing of the regenerator unit 31. The weak solution separated and collected at the bottom of the regenerator unit container 38 is supplied to the absorbent dispersion device 51 provided at the top of the absorption unit 36 via the weak solution heat exchanger 40 and the pressure reducing valve 57.

[0009] The operation of the device thus constructed will be described below. The absorbing liquid (weak solution) introduced to the top of the absorbing unit container 50 is sprayed inside the container (body side) by the absorbing liquid spraying device 51. The sprayed absorbing liquid flows down along the outer surface of the heat transfer wall of the absorption heat recovery heat exchange section 52 or falls down in space. In the process, the absorbing liquid comes into contact with and absorbs the refrigerant vapor passing through the absorbing and radiating section 53, whereby the refrigerant concentration of the absorbing liquid is gradually increased. The absorption heat generated by the absorption of the refrigerant vapor is the absorption liquid (strong solution) flowing inside the absorption heat recovery heat exchange unit 52.
And is used as part of the heat required for the regeneration action.

The absorbing liquid that has passed through the area of the absorption heat recovery heat exchange section 52 flows down the outer surface of the heat transfer wall of the absorption heat radiation section 53 or falls down in the space. In the process, the absorbing liquid comes into contact with and absorbs the refrigerant vapor introduced into the absorption container, thereby further increasing the refrigerant concentration of the absorbing liquid. The absorbed heat generated at this time is taken into the heat medium flowing in the heat exchange channel of the absorbed heat radiating section 53. The absorption liquid that has passed through the absorption heat radiation section 53 becomes an absorption liquid (strong solution) having a low temperature and a high refrigerant concentration, and accumulates at the bottom of the absorption unit container 50.

The absorption liquid (strong solution) accumulated at the bottom of the absorption unit container 50 is pressurized by the solution circulation pump 37, introduced into the heat exchange flow path of the decomposer 42 and heated, and then described above. The heat is introduced into the heat exchange channel of the absorption heat recovery heat exchange section 52 from the lower entrance of the absorption heat recovery heat exchange section 52. The absorbing liquid (strong solution) introduced into the heat exchange flow path flows toward the upper part, and is heated by the above-mentioned absorption heat to approach the upper outlet and rises in temperature, and starts boiling when reaching the saturation temperature,
Further, the refrigerant concentration is decreased while increasing the temperature.

In the absorption heat recovery heat exchange section 52, the absorbing liquid which has become a gas-liquid two-phase flow by boiling is absorbed by the absorption heat recovery heat exchange section 5.
2 is sent to the rectifier 41 of the regenerator unit 31 from the upper outlet. The two-phase flow absorbing liquid introduced into the rectifier 41 is separated into vapor (a mixture of ammonia vapor and water vapor) and the absorbing liquid. The vapor increases the refrigerant concentration in the process of ascending the concentration stage 41b of the rectifier 41, and performs heat exchange with the low-temperature absorbent (strong solution) in the decomposer 42 to further condense and remove moisture, thereby removing the refrigerant vapor. After the purity is increased, it is supplied to the condenser 32. In the uppermost part of the regenerator unit 31, a part of the refrigerant vapor is condensed by the decomposer 42 and flows down to the rectifier 41, where it contacts the rising vapor to increase the refrigerant purity of the vapor. I do.

On the other hand, in the process of moving down the recovery stage 41a of the rectifier 41, the separated absorbent contacts the vapor rising from below, the refrigerant concentration decreases, and the weak solution heat exchanger 40
When passing through the outer surface of the regenerator / heat input device 39 and the outer surface of the regenerative heat input device 39, the liquid becomes an absorbent having a low refrigerant concentration (weak solution) and collects at the bottom of the regenerator unit container 38. The absorbing liquid (weak solution) collected at the bottom of the regenerator unit container 38 passes through the internal flow path of the weak solution heat exchanger 40 and the pressure reducing valve 57 as described above, and the absorbing liquid spraying device 51 at the top of the absorbing unit 36. Supplied to Absorbent liquid (weak solution) collected at the bottom of the regenerator unit container 38
Further, the steam is heated by the regeneration heat input device 39 to generate steam (a mixture of ammonia vapor and steam), and this steam comes into contact with the absorbing liquid flowing down in the process of ascending the recovery stage 41a of the rectifier 41. Increase the refrigerant concentration.

Thus, the absorption step and the regeneration step are repeated, and in the process, the evaporator 35 or the absorption / radiation section 53
From the system, cold or warm heat is taken out of the system.

In the high-efficiency GAX cycle, as described above, the absorption liquid having a high ammonia concentration flowing in the absorption heat recovery heat exchange section 52 is boiled in the absorption heat recovery heat exchange section 52 to perform heat recovery. In this case, the maximum temperature in the regenerator is high, and the load on the rectification operation increases.

As a structure of a general rectifier, a structure having a shelf structure shown in FIG. 6 or a structure in which a filler such as a Raschig ring is inserted is used.

[0017]

However, the range of the optimum value of the combination of the flow rates of the absorbing liquid and the vapor is narrow in the tray, and the rectification operation becomes insufficient when the flow rate is changed by the capacity control or the like. There was a problem. Further, in order to solve this, in Japanese Patent Application Laid-Open No. Hei 5-280830, the shelf is provided with a flow rate adjusting function. However, these additional functions complicate the device.

On the other hand, the one in which a filler such as a Raschig ring is inserted has a simple structure and is often used for rectification operations. There was a problem that the contact of the liquid became poor.

An object of the present invention is to secure a stable gas-liquid contact area and maintain the rectification effect even when the flow rate of the absorption liquid and the flow rate of the vapor of the absorption heat pump change.

[0020]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a rectifying section for rectifying a vapor generated from an absorbing liquid in which a refrigerant and an absorbent are mixed to concentrate a refrigerant component. , A condenser for condensing the concentrated refrigerant vapor, an evaporator for evaporating the liquid refrigerant condensed in the condenser, and an absorber for absorbing the refrigerant vapor evaporated in the evaporator into an absorbent. And a unit, wherein the rectifier has a mesh surface arranged vertically along a liquid flow lower surface of the gas-liquid contact portion thereof. And

The liquid that rectifies the vapor by gas-liquid contact with the vapor rising from below spreads over the entire mesh surface by the capillary effect of the mesh surface while flowing down along the mesh surface, and the gas flows on both sides of the mesh surface. Performs rectification as a liquid contact surface. Even if the liquid flow rate decreases, it spreads over the entire mesh surface due to the capillary effect, and both sides of the mesh surface become gas-liquid contact surfaces, so that a wide gas-liquid contact area can be secured.

The material constituting the mesh surface may be not only metal but also plastic, ceramic or the like. Further, the mesh surface may be formed by a combination of a plurality of meshes formed of any of metal, plastic, and ceramic. When the mesh surface is formed by a wire mesh, relatively closed ones, such as a plain woven wire mesh and a tatami woven wire mesh, easily cause a capillary effect.

The mesh surface may be formed in a cylindrical shape or a flat plate shape. In the case of a cylindrical shape, it is desirable to change the radius of the tube and to arrange a plurality of tubes concentrically, and in the case of a plate shape, it is preferable to arrange a plurality of tubes in parallel.

Regardless of whether the mesh surface is formed in a cylindrical shape or a flat plate shape, the upper end of the mesh surface is inserted and fixed in an opening at the bottom of a dish-shaped liquid distribution device for temporarily storing liquid, and is temporarily fixed to the liquid distribution device. It is preferable that the stored liquid flow down to the mesh surface through the opening. With this configuration, the liquid temporarily stored in the liquid distribution device easily spreads over the entire mesh surface.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration of an absorption heat pump to which the present invention is applied. The heat pump shown in FIG.
Is different from the heat pump shown in FIG.
Since only the structure of the rectifier 41 provided in 1 is provided, the other structures are denoted by the same reference numerals as in FIG. 6 and the description thereof is omitted.

The rectifying device 41 includes a liquid dispersing device 41D disposed below the condensing device 42 and a dish-like liquid disposed at a position where the absorbing liquid (strong solution) 55 is supplied from the absorbing unit 36. A dispersing device 41C, a wire mesh plate 41F formed in a cylindrical shape and disposed concentrically below the liquid dispersing device 41D with the axis up and down, and an axial line formed vertically below the liquid dispersing device 41C also formed in a cylindrical shape. And a wire mesh plate 41E concentrically arranged in the direction. The liquid dispersion device 41D and the wire mesh plate 41F constitute a concentration unit 41b, and the liquid dispersion device 41C and the wire mesh plate 41E constitute a recovery unit 41a.

The wire mesh is a plain weave wire mesh shown in FIG. 2, but any wire mesh such as a tatami weave wire mesh may be used as long as it is relatively tight.
A plurality of these wire meshes were overlaid and brought into close contact with each other by crimping or sintering to form a wire mesh plate. This was processed into a plurality of cylinders having different radii, then cut to a predetermined length, arranged concentrically, and joined to the lower surface of the liquid dispersion device.

In FIG. 1, the liquid dispersing device 41D and the wire mesh plate 41F, and the liquid dispersing device 41C and the wire mesh plate 41E are shown in a separated form.
In order to make the shape of E easy to understand, it is drawn in a separated form, and is actually connected. FIG. 3 shows the state of the connection between the liquid dispersion device and the wire mesh plate. A notch is formed in the upper part of the wire mesh plate, and its protruding portion is inserted and fixed in a groove-shaped opening formed in the bottom surface of the liquid dispersion device. Although not shown in FIGS. 1 and 3, on the bottom surface of the liquid dispersion device,
As shown in FIG. 4, a plurality of short pipes 49 penetrating the bottom face are mounted, and form a vertical flow path for steam.

In the regenerator unit 31 having the above configuration,
The liquid condensed on the outer surface of the condensing device 42 drops from there and collects in the liquid dispersion device 41D disposed below the condensing device 42. The liquid collected in the liquid dispersion device 41D is supplied to the liquid dispersion device 4D.
It seeps into the wire mesh plate 41F inserted into the opening on the bottom surface of the 1D, spreads over the wire mesh plate 41F, and descends. The wire mesh plate 41F is formed by laminating several wire meshes, and the capillarity effect becomes remarkable when they are brought into close contact with each other, so that the absorbing liquid permeates so as to be sucked into the wire mesh plate 41F. The vapor rises between the wire mesh plate and the wire mesh plate and between the wire mesh plate and the inner peripheral surface of the regenerator unit container 38, and comes into contact with the absorbing liquid descending the wire mesh plate 41F to be subjected to rectification to increase the ammonia concentration. Go. The absorbent passed through the concentrating unit 41b is supplied to the liquid dispersing device 4 of the collecting unit 41a.
Collected in 1C. The absorption liquid collected in the liquid dispersion device 41C passes through the absorption heat recovery heat exchange unit 52, and is mixed with the absorption liquid (strong solution) whose temperature has been raised by heat recovery. Similarly, the mixed absorbing liquid is supplied from the liquid dispersion device 41C to the collecting section 41a.
And descends along the wire mesh plate 41E. In this descending process, the descending absorbing liquid comes into contact with steam generated by heating in the regenerative heat input device 39, releases ammonia, and lowers its own ammonia concentration.

As described above, since the wire mesh plate is used for the absorption liquid flow path (the lower surface of the flow) of the rectifier, the absorption liquid penetrates the wire mesh plate and spreads down by the capillary effect, and descends. Even when the state becomes wet with the absorbing liquid and the flow rate of the absorbing liquid decreases, the gas-liquid contact area can be maintained at a value larger than the rate of decrease in the flow rate. Therefore, even if the flow rate of the absorbing liquid flowing down and the amount of steam rising change, the flow rate range in which a constant gas-liquid contact area can be maintained is widened, and a stable rectification effect can be obtained.

Although the wire mesh plate is cylindrical in the above embodiment, the wire mesh plate may be formed in a flat plate shape instead of a cylindrical shape so that a plurality of the metal wire plates are suspended in parallel. The pitch) may also be set freely according to the planned flow rates of the absorbing liquid and steam.

The mesh surface may be formed by forming a mesh exhibiting a capillary effect by using a plastic, ceramic, or the like instead of the wire mesh, or a combination of nets formed of these different materials may be used. The flow lower surface of the liquid may be configured.

[0033]

According to the present invention, since the lower surface of the absorbing liquid which performs the rectifying action by gas-liquid contact while flowing down in the rectifier is constituted by a mesh surface having a capillary effect, the flow rate fluctuation of the absorbing liquid Even if there is, fluctuation of the gas-liquid contact area can be reduced,
The rectification action can be maintained stably.

[Brief description of the drawings]

FIG. 1 is a system diagram showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a plan view showing details of a portion of the embodiment shown in FIG. 1;

FIG. 3 is a perspective view showing details of a part of the embodiment shown in FIG. 1;

FIG. 4 is a plan view showing details of a part of the embodiment shown in FIG. 1;

FIG. 5 is a perspective view showing an example of the related art.

FIG. 6 is a system diagram showing an example of the related art.

[Explanation of symbols]

31 Regenerator unit 32 Condenser 33 Refrigerant heat exchanger 34 Expansion valve 35 Evaporator 36 Absorption unit 37 Solution circulation pump 38 Regenerator unit container 39 Regeneration heat input device 40 Weak solution heat exchanger 41 Rectifier 41a Rectifier Recovery stage 41b Concentration stage of rectifier 41C Liquid dispersion device of recovery stage 41D Liquid dispersion device of concentration stage 41E Wire mesh plate of recovery stage 41F Wire mesh plate of concentration stage 42 Decompressor 43a Absorbent (strong solution) 44 Refrigerant vapor 45 Heat exchanger 46 Liquid refrigerant 47 Refrigerant dispersing device 48 Heat exchanger 49 Short tube 50 Absorbing unit container 51 Absorbing liquid dispersing device 52 Absorbing heat recovery heat exchanging unit 53 Absorbing and radiating unit 55 Absorbing liquid (strong solution) 57 Pressure reducing valve

Claims (9)

[Claims] 1. A regenerator unit having a rectifier unit for rectifying a refrigerant component by rectifying an absorbent vapor generated from an absorbent mixture of a refrigerant and an absorbent, and condensing the concentrated refrigerant vapor. A condenser, an evaporator that evaporates the liquid refrigerant condensed in the condenser, and an absorber unit that absorbs the refrigerant vapor evaporated in the evaporator into an absorbent, in an absorption heat pump configured to include: An absorption type heat pump, wherein the rectifier has a mesh surface arranged along a vertical direction as a liquid flow lower surface of the gas-liquid contact portion. 2. The absorption heat pump according to claim 1, wherein the mesh surface is made of a mesh made of any one of metal, plastic, and ceramic. 3. The absorption heat pump according to claim 1, wherein the mesh surface is made of a combination of meshes made of any of metal, plastic, and ceramic. 4. The absorption heat pump according to claim 1, wherein the mesh surface is formed of a mesh made of at least two of metal, plastic, and ceramic. 5. The absorption heat pump according to claim 1, wherein the mesh surface is made of a combination of meshes made of any two or more of metal, plastic, and ceramic. 6. The absorption heat pump according to claim 1, wherein the mesh surface is formed in a cylindrical shape. 7. The absorption heat pump according to claim 1, wherein the mesh surface is formed in a flat plate shape. 8. An upper end of a cylindrical mesh surface is inserted and fixed in an opening at the bottom of a dish-shaped liquid distribution device for temporarily storing liquid, and the liquid temporarily stored in the liquid distribution device passes through the opening. The absorption heat pump according to claim 6, wherein the heat pump is configured to flow down to a mesh surface. 9. An upper end of a flat plate-shaped mesh surface is inserted and fixed in an opening at the bottom of a dish-shaped liquid distribution device for temporarily storing liquid, and the liquid temporarily stored in the liquid distribution device passes through the opening. The absorption heat pump according to claim 7, wherein the absorption heat pump is configured to flow down to a mesh surface.