JPH07318195A - Absorption type refrigerating equipment - Google Patents

Abstract

PURPOSE:To enable execution of a high-load operation by a small-sized generator and also reduction of production of a nitrogen oxide by a construction wherein a flat combustion chamber having aerated combustion type burner provided is combined with a large number of combustion gas flow passage pipes juxtaposed inside a heating vessel. CONSTITUTION:A totally aerated burner 6 is used as a heating source in absorption type refrigerating equipment, and therefore the dimension in the vertical direction of a combustion chamber 60 can be minimized. The flat combustion chamber 60 is combined with multipipe type combustion gas flow passage pipes 55 provided inside a vertical type cylindrical heating vessel 5 for a bottom plate 52 of which the ceiling wall of the combustion chamber 60 is used, and therefore a combustion gas flows rapidly into the combustion gas flow passage pipes 55 to be subjected to heat exchange and cooled down. Therefore a time of staying of the combustion gas in a high- temperature state is shortened and a nitrogen oxide is produced little. Since the center of the bottom plate 52 is formed in the shape of a spherical shell being protruberant upward, the combustion gas flows to the center along a spherical surface and flows smoothly into the combustion gas flow passage pipes 55. Accordingly, production of the nitrogen oxide is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigeration system using an aqueous solution of ammonia, lithium bromide or the like as a working fluid.

[0002]

2. Description of the Related Art An absorption refrigerating apparatus using an aqueous solution of ammonia, lithium bromide or the like heats the aqueous solution with a generator to generate a vapor of a refrigerant such as ammonia, and liquefy the vapor of the refrigerant with a condenser, It flows into the low-pressure evaporator through the expansion valve, and the freezing action is performed. The refrigerant evaporated again in the evaporator is absorbed in the aqueous solution diluted by the evaporation of the refrigerant in the absorber. The aqueous solution having a high concentration due to this absorption is circulated through the generator by a pump. In this type of absorption refrigeration system, the working fluid is generated by the generator at 10 atm or more,
Since it has a high temperature and high pressure of about 200 ° C, it is applied to relatively large refrigeration equipment.

[0003]

However, it is desired to increase the load of the absorption refrigeration system and reduce the size of the absorption refrigeration system to apply it to a home air conditioner / hot water supply device. An object of the present invention is to provide an absorption refrigeration system that can be operated under a high load with a small generator and that can reduce the generation of nitrogen oxides.

[0004]

SUMMARY OF THE INVENTION According to the present invention, a generator for generating a mixed working fluid vapor of a refrigerant and an absorbing fluid from a working fluid obtained by mixing a refrigerant and an absorbing fluid, and rectifying the mixed working fluid vapor. A rectifier for concentrating the refrigerant component, a condenser for condensing the gas refrigerant component of the concentrated mixed working fluid vapor, an evaporator for evaporating the liquid refrigerant condensed by the condenser, and an evaporator for the evaporator In an absorption type refrigerating apparatus including an absorber that absorbs the refrigerant vapor in diluted working fluid, the generator contains the working fluid therein, and a vertical cylindrical heating container provided with a bottom plate. , A flat combustion chamber provided under the bottom plate of the heating container and having a full primary (air combustion type) burner installed therein, and a number of lower holes formed in the bottom plate and the upper part of the heating container. Connected with the formed upper hole and arranged side by side in the heating container Characterized in that comprising a number of combustion gas flow pipe. In the configuration according to claim 2, the bottom plate has a central spherical shell portion that bulges upward, the plurality of lower holes are opened in the central spherical shell portion, and the multiple upper holes are the heating container. It is characterized in that it is formed on the outer peripheral upper part.

[0005]

In this absorption refrigerating apparatus, since all primary burners are used as the heat source, the vertical dimension of the combustion chamber can be minimized. Further, since the flat combustion chamber is combined with the multi-tube combustion gas passage pipe in the vertical cylindrical heating container having the bottom wall of the ceiling wall of the combustion chamber as the heating container, the combustion gas is quickly discharged. Then, the heat is exchanged by flowing into the combustion gas passage pipe to cool the combustion gas. Therefore, the residence time of the combustion gas in the high temperature state is shortened, and the generation of nitrogen oxide is small. In the configuration of claim 2, since the center of the bottom plate is formed in a spherical shell shape that bulges upward, the combustion gas tends to flow to the center along the spherical surface, and smoothly flows into the combustion gas passage pipe. Therefore, the residence time is further shortened, and the generation of nitrogen oxide can be reduced.

[0006]

EXAMPLE FIG. 7 and FIG. 8 show a cooling and heating water heater 100 using an absorption type refrigeration system using an aqueous ammonia solution as a working fluid.
Indicates. The heating / cooling water heater 100 is a generator 1 for generating ammonia gas, a heat source side heat exchanger 11 that acts as a condenser during the cooling operation shown in FIG. 7, and acts as an evaporator during the heating operation shown in FIG. 8, and during the cooling operation. A utilization side heat exchanger 3 that functions as an evaporator and a condenser during heating operation, and an absorber 4 are provided.

An inter-refrigerant heat exchanger 2 for exchanging heat between the liquid refrigerant and the gas refrigerant is arranged between the heat source side heat exchanger 11 and the use side heat exchanger 3. A rectifier 12 and a dephlegmator 13 are sequentially stacked above the generator 1.

These devices are connected by a working liquid flow passage, and a passage is formed in the working liquid flow passage that connects the demultiplexer 13, the heat source side heat exchanger 11, the inter-refrigerant heat exchanger 2, and the use side heat exchanger 3. A first four-way switching valve 21 and a second four-way switching valve 22 for switching are provided. The inter-refrigerant heat exchanger 2 is a double-tube heat exchanger composed of an inner pipe 2a and an outer pipe 2b. The inner pipe 2a has a liquid refrigerant dedicated flow passage, and the outer pipe 2b has a gas refrigerant dedicated flow. It is a road.

The first four-way switching valve 21 allows the gas refrigerant from the generator 1 to flow into the heat source side heat exchanger 11 during the cooling operation, and absorbs the gas refrigerant from the outer pipe 2b of the inter-refrigerant heat exchanger 2. Flow into vessel 4. During the heating operation, the gas refrigerant from the generator 1 is switched into the utilization side heat exchanger 3 and the gas refrigerant from the heat source side heat exchanger 11 is caused to flow into the absorber 4 during the heating operation.

The second four-way switching valve 22 allows the gas refrigerant from the use side heat exchanger 3 to flow into the outer pipe 2b side of the inter-refrigerant heat exchanger 2 during the cooling operation, and to the outside of the inter-refrigerant heat exchanger 2. Tube 2b
A gas refrigerant is caused to flow into the absorber 4. During the heating operation, the gas refrigerant from the generator 1 is switched to flow into the utilization side heat exchanger 3 and the outer pipe 2 of the inter-refrigerant heat exchanger 2 is switched during the heating operation.
The gas refrigerant from b is allowed to flow into the absorber 4.

As shown in FIGS. 1 to 5, the generator 1 includes a heating container 5 and a gas burner 6. The heating container 5 heats an aqueous ammonia solution (ammonia dilute solution), which is a dilute solution, to about 200 ° C. at 10 to 20 atmospheres to boil and generate a mixed vapor of ammonia and water. The heating container 5 is provided with a vertical cylinder body 51 having an entire upper surface opened to communicate with a rectifier to be described later, and a bottom plate 52 welded to a lower portion of the cylinder body 51.

The bottom plate 52 has a central spherical shell 5 bulging upward.
a, a cylindrical portion 5b extending downward from the outer periphery of the central spherical shell portion 5a, and a collar-shaped portion 5c extending outward from the lower end of the cylindrical portion 5b, the outer periphery of the collar-shaped portion 5c. Is the cylindrical body 51
Is welded to the lower inner wall of the. The bottom plate 52 may have a flat plate shape, but the reason why the central portion of the bottom plate 52 is formed in a spherical shell shape in this embodiment is that the bottom plate 52 has a thin thickness and can withstand the high pressure in the heating container.

A dilute solution outflow pipe 20 for letting out a dilute ammonia solution into the center of the heating vessel 5 and supplying it to the absorber 4.
Is inserted from the top to the bottom. Below the bottom plate 52 is a combustion chamber 60 of the gas burner 6, and a forced draft type primary combustion plate type gas burner 6 is attached to the bottom of the combustion chamber 60. The central spherical shell portion 5a of the bottom plate 52 is provided with a total of 32 lower holes 53 on the quadruple concentric circles, eight at equal intervals. In the upper part of the vertical cylindrical body 51, eight upper and lower holes 54 are vertically arranged in four stages at a total of 32 upper holes 54.
Has been opened. As in this embodiment, by forming the upper holes 54 in four stages in the upper and lower four steps at equal intervals, the pipe space is made compact and the pipe diameter is increased (heat exchange area of the heat exchange area while maintaining proper intervals between the pipes). Increase) is possible.

On the outer circumference of the heating container 5, an outer cylinder 7 forming a cylindrical closed space 70 is coaxially provided on the outer circumference of the heating container 5. The outer cylinder 7 includes a cylindrical body 71, an annular upper plate 72 that closes the upper end of the cylindrical body 71, and an annular lower plate 73 that closes the lower end of the cylindrical body 71. A heat insulating material 74 is stretched on the inner peripheral wall of the cylindrical body 71. Cylinder 71
Further, an exhaust port 75 communicating with a lower end of a combustion gas retention passage 77, which will be described later, provided in the cylindrical closed space 70 is opened at the lower end of the heat insulating material 74, and an exhaust pipe 76 is provided so as to project in the horizontal direction. The exhaust port 75 may be provided in the annular lower plate 73 and the exhaust cylinder 76 may be provided so as to project downward.

An annular combustion gas retention passage 77 is formed between the inner peripheral wall of the heat insulating material 74 and the outer peripheral wall of the heating container 5. Corrugated fins 56 as heat absorption fins are provided in the middle of the outer peripheral wall of the heating container 5 in the vertical direction by shifting a half pitch.
It is located in the combustion gas retention passage 77 joined to the step by brazing or the like. In the heating container 5, 32 combustion gas passage tubes 55 bent in an inverted L shape are arranged in parallel vertically. The lower end of each combustion gas passage pipe 55 is a lower hole 53.
And the upper end is welded to the upper hole 54.
And the upper part of the combustion gas retention passage 77.

In this generator 1, the combustion gas generated by the all-primary air combustion of the gas burner 6 flows from the combustion chamber 60 to the upper portion of the combustion gas retention passage 77 through the 32 combustion gas passage pipes 55. . The combustion gas that has entered the combustion gas retention passage 77 comes down while coming into contact with the corrugated fins 56, and is discharged to the outside through the exhaust port 75 and the exhaust pipe 76. During this time, the heat generated by the gas burner 6 is transmitted to the internal working fluid via the bottom plate 52 of the heating container 5, and then heats the working fluid via the tube wall of the combustion gas passage tube 55.
The remaining thermal energy is absorbed by the corrugated fins 56 and the cylindrical body 51 and is supplied to the hydraulic fluid.

As described above, the generator 1 has a small physique and an extremely large heat transfer area, and since the contact time between the combustion gas and the heat transfer surface is long, the heat efficiency is 80% at maximum.
Can be increased to the extent. Along with this, the combustion load can be increased, and a high refrigerating capacity as a refrigerating device can be obtained. Since the flat combustion chamber 60 is combined with the multi-tube combustion gas passage pipe 55 in the vertical cylindrical heating container 5 having the ceiling wall of the combustion chamber 60 as the bottom plate 52 as the heating container 5. The combustion gas quickly flows into the combustion gas passage pipe 55 for heat exchange, and the combustion gas is cooled. Therefore, the residence time of the combustion gas in a high temperature state is shortened, and the generation of nitrogen oxides is small. In particular, since the bottom plate 52 has a spherical shell shape with the center thereof bulging upward, the combustion gas tends to flow to the center along the spherical surface, and flows smoothly into the combustion gas passage pipe 55.
Therefore, the residence time is further shortened, and the generation of nitrogen oxide can be reduced.

FIG. 6 is a graph of measured data of the air-fuel ratio of the air-fuel mixture and the generation of nitrogen oxides. In the figure, a is a flow of the combustion gas to the outer circumference of the heating container 5 for heat exchange, and when the combustion gas flow pipe 55 is not provided, a is a bottom plate 52 serving as a ceiling wall of the flat combustion chamber 60 of the present invention. The case where the lower hole 53 of the combustion gas passage pipe 55 is provided in FIG. From this graph, it can be seen that the gas burner 6 of the present invention produces less nitrogen oxides even with a premixed gas that is close to the stoichiometric air-fuel ratio. Therefore, the generation of nitrogen oxides can be maintained at a low level even under the combustion condition where the excess air ratio is close to 1.0.

As shown in FIG. 1, FIG. 4 and FIG. 5, the gas burner 6 is a ceramic circular combustion plate 61 in which a large number of flame holes are formed in a predetermined pattern, and the combustion plate 61 is formed into the cylindrical body 51. And a combustion plate holding frame 62 for attaching to the lower end of the. The combustion plate holding frame 62 is provided with a fitting cylindrical portion 6A at the center thereof, and has an outer periphery serving as a fastening edge 6B to a flange 57 provided on the lower end surface of the cylindrical body 51. A combustion plate 61 and a perforated plate 63 for achieving a uniform distribution of the air-fuel mixture are fitted into the fitting cylindrical portion 6A, and the combustion plate 6 is inserted into the fitting plate 6A.
The edge of the upper surface of 1 is pressed by an annular edge metal 61A. Above the combustion plate 61, an ignition electrode S and a misfire detection frame rod F are mounted so as to penetrate the cylindrical body 51.

On the lower surface of the combustion plate holding frame 62, there is fastened a casing 64 which also serves as a mixing pipe for combustion air and fuel gas. A rectangular cylindrical air introduction passage 65 is provided in the casing 64 in the tangential direction, and a gas nozzle pipe 66 having a plurality of gas ejection holes 6C on the downstream side is inserted into the air introduction passage 65 so as to intersect with each other. ing. Combustion air is supplied from the blower B to the air introduction passage 65, and fuel gas is supplied from the gas source G to the gas nozzle pipe 66.

A cup-shaped portion 6E having an upper opening 6D facing the lower surface of the combustion plate 61 is provided in the casing 64.
And an inner / outer communication port 6F opened on the side wall of the cup-shaped portion 6E
A mixture gas flow path forming member 67 including a vertical plate-shaped partition wall plate 6G protruding outward from an edge of the inner / outer communication port 6F is fitted. The partition wall plate 6G comes into contact with one of the most downstream end edges of the air introducing passage 65 to partition the inside of the casing 64, and between the air introducing passage 65 and the outer periphery of the cup-shaped portion 6E and the inner periphery of the casing 64. The mixing flow path 6 that goes around the annular flow path 68, enters the cup-shaped portion 6E from the communication port 6F, passes through the porous plate 63, and reaches the lower surface of the combustion plate 61.
9 is formed.

Since the mixing channel 69 is formed longer by the annular channel 68, the length for complete premixing can be formed in a compact size. As a result, it is possible to burn the air-fuel mixture with a uniform and lean air-fuel ratio, and it is possible to reduce the generation of nitrogen oxides. The annular space between the outer periphery of the cylindrical portion 5b of the bottom plate and the inner periphery of the cylindrical body 51 is filled with hydraulic fluid to form a water jacket 50 that surrounds the outer periphery of the combustion chamber 60. The water jacket 50 covers the cylindrical body 51 on the outer periphery of the combustion chamber 60 so that the heat of the combustion gas in the combustion chamber 60 is absorbed by the water jacket 50, so that the heat of the combustion gas is absorbed by the cylindrical body 51. The loss released to the outside is prevented and high thermal efficiency is obtained.

Next, the operation of the cooling / heating water heater 100 will be described. When the working fluid in the heating container 5 of the generator 1 is heated by the gas burner 6, a mixed vapor of ammonia as a refrigerant and water as an absorbing fluid is generated from the working fluid, and the mixed vapor passes through the rectifier 12. Rise. In this rectification unit 12, five storage tanks 1A to 1E are formed, and the working liquid (ammonia concentrated solution) supplied from the absorber 4 to the generator 1 is sequentially transferred from the upper storage tank to the lower tank. Run down to the storage shelf.

In the rectifier 12, every time the mixed vapor of ammonia and water rising from below passes through each storage rack, the water is condensed and mixed due to the temperature drop caused by the contact with the concentrated ammonia solution from above. Ammonia concentration in steam rises. The mixed vapor concentrated in the rectifier 12 is further endothermic by the upper partial condenser 13 and water is condensed and separated to become about 99.8% ammonia gas.

[Cooling operation, see FIG. 7] As shown in FIG.
This gas refrigerant is supplied to the first four-way switching valve 21 as indicated by an arrow L.
And is supplied to the heat source side heat exchanger 11 which functions as a condenser. In the heat source side heat exchanger 11, it is air-cooled by the fan Fa to release the heat of condensation and liquefy to become ammonia liquid (liquid refrigerant). This liquid refrigerant is the inner tube 2 of the heat exchanger 2 between refrigerants.
After being decompressed by the capillary tube 23 acting as a decompression mechanism through a, it flows into the utilization side heat exchanger (acting as an evaporator) 3 of the double pipe structure.

The liquid refrigerant exchanges heat with the use side heat medium (water in this embodiment) supplied from the indoor unit in the use side heat exchanger 3 by driving the pump P1 through the use side heat medium passage 31. Then, it evaporates (water is cooled and becomes a cooling heat source for cooling), and again becomes a gas refrigerant. This gas refrigerant is used in the second four-way switching valve 2
2 is sent to the outer pipe 2b of the inter-refrigerant heat exchanger 2 through which the liquid refrigerant (passing inside the inner pipe 2a) from the heat source side heat exchanger 11 is pre-cooled and itself preheated, and then the first It is fed to the absorber 4 via the four-way switching valve 21 and the second four-way switching valve 22.

This gas refrigerant is again absorbed in the working fluid supplied from the generator 1 to the absorber 4 in the absorber 4. That is, a sprayer 42 for the working fluid is provided at the uppermost stage in the container 41 of the absorber 4, and the heat exchanger from the generator 1 to the heat exchanger in the rectifier is provided to the sprayer 42 as indicated by an arrow L1. The working liquid (3% ammonia dilute solution) is supplied through the capillary tube 24 that is cooled by 26 and acts as a pressure reducing mechanism.

The diluted ammonia solution is sprayed from the sprayer 42 in the container 41, absorbs the gas refrigerant supplied from the heat exchanger 3 on the use side into the container 41, and drops into the liquid pool 43 at the bottom of the container 41. To do. The working liquid (concentrated ammonia solution) in the liquid pool 43 is supplied by the pump P2 to the arrow L2 in FIG.
, L3 is pumped. During this period, the heat exchanger 25 of the partial condenser 13 and the absorber 4 for recovering absorbed heat
After being heat-exchanged and heated by the heat exchanger 44 inside, the rectifier 1
It is supplied to the uppermost liquid storage shelf 1A in 2.

[Heating operation, see FIG. 8] As shown in FIG.
The first four-way switching valve 21 and the second four-way switching valve 22 are switched, and the gas refrigerant (ammonia gas) flowing through the refrigeration circuit
The flow direction of is switched. The gas refrigerant (concentration 99.8%) generated in the partial condenser 13 passes through the first four-way switching valve 21 and the second four-way switching valve 22 as shown by the arrow L4, and is used side heat acting as a condenser. The heat flows into the exchanger 3, passes through the use-side heat medium flow passage 31, exchanges heat with the use-side heat medium (water in this embodiment) supplied from the indoor unit, and condenses. The water is heated by this and becomes a heat source for heating in the indoor unit.

The refrigerant liquefied in the use side heat exchanger 3 is decompressed by the capillary tube 23, and then is supplied to the heat source side heat exchanger 11 acting as an evaporator through the inner pipe 2a of the inter-refrigerant heat exchanger 2. And evaporates, and further the first four-way switching valve 2
1, outer tube 2b of heat exchanger 2 between refrigerants, second four-way switching valve 22
And is supplied to the absorber 4. The generation, rectification, and partial condensation of the water-ammonia mixed vapor in the generator 1 and the like and the absorption of the ammonia gas refrigerant in the absorber are the same as in the cooling operation shown in FIG. The flow of (concentrated ammonia solution and diluted ammonia solution) is the same as in FIG. 7.

In this embodiment, in the absorber 4, in addition to the heat exchanger 44 for recovering the absorbed heat, a heat exchanger 45 for a heat source such as hot water supply and a heat exchanger 46 for both cooling and heating are provided. The heat exchanger 45 for a heat source such as hot water supply is connected to the hot water supply tank 14, the bath 15, the bathroom dryer 16 and the like via the pump P3 to form a hot water supply cycle using hot water as a heat medium.

On the inlet side and the outlet side of the cooling / heating heat exchanger 46, the branch outward path 3 branched from the use side heat medium flow path 31 at the outlet of the use side heat exchanger 3 via the three-way switching valve V1.
2 and a branch return path 33 that joins the downstream side of the three-way switching valve V1.
And the sides are connected respectively. The outlet side of the pump P4 in the cooling water flow path 35 connecting the heat radiation heat exchanger 34 and the pump P4 is connected to the branch outward path 32 via the three-way switching valve V2, while the cooling water flow path 35 is connected.
The inlet side of the heat dissipation heat exchanger 34 is
Is connected via a three-way switching valve V3.

In the cooling operation, the three-way switching valves V2 and V3 are opened on the cooling water flow path 35 side and closed on the branch outward path 32 and branch return path 33 sides as shown in FIG. As shown in FIG.
It is controlled so that the side is closed and the branch outward path 32 and the branch return path 33 are opened. Therefore, during the cooling operation, the heat medium for heating / cooling 46 is not supplied with the heat medium on the use side, but the cooling water is supplied from the heat exchanger 34 for heat radiation, and during the heating operation, the heat exchanger 46 is supplied to the heat exchanger 46. Is supplied with the heat medium on the use side, and the cooling water from the heat exchanger 34 for heat radiation is not supplied. Although the bottom plate 52 of the heating container 5 is bulged upward in the above embodiment, the nitrogen oxide can be reduced, which is the object of the present invention, if the bottom plate 52 is bulged upward.

[Brief description of drawings]

FIG. 1 is a front sectional view of a generator of an absorption refrigerating apparatus according to the present invention.

FIG. 2 is a perspective view of an upper portion of the heating container.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a sectional view taken along line BB of FIG.

FIG. 5 is an assembly diagram of a gas burner.

FIG. 6 is a graph showing data on the amount of nitrogen oxides generated in a gas burner.

FIG. 7 is a schematic configuration diagram of an air conditioner using an absorption refrigeration system.

FIG. 8 is a schematic configuration diagram of a cooling / heating apparatus using an absorption refrigeration apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Generator 4 Absorber 5 Heating container 6 Gas burner 7 Outer cylinder 5a Central spherical shell part 5b Cylindrical part 5c Collar part 12 Fractionator 13 Fractionator (condenser) 52 Bottom plate 53 Lower hole 54 Upper hole 55 Combustion gas Flow tube 60 Combustion chamber

Claims (2)

[Claims] 1. A generator for generating a mixed working fluid vapor of a refrigerant and an absorbing fluid from a working fluid obtained by mixing a refrigerant and an absorbing fluid, and a rectifier for rectifying the mixed working fluid vapor to concentrate a refrigerant component. A condenser for condensing the gas refrigerant component of the concentrated mixed working fluid vapor; an evaporator for evaporating the liquid refrigerant condensed by the condenser; and a refrigerant vapor evaporated by the evaporator in a diluted working fluid. In an absorption type refrigerating apparatus having an absorber for absorbing the liquid, the generator contains a working liquid contained therein, a vertical cylindrical heating container having a bottom plate, and a bottom plate of the heating container. The heating container provided with a flat combustion chamber in which all primary burners are installed, and a number of lower holes formed in the bottom plate and an upper hole formed in the upper part of the heating container are connected to each other. Characterized by a number of combustion gas flow passages arranged side by side Absorption type refrigerating apparatus to. 2. The bottom plate according to claim 1, wherein the bottom plate has a central spherical shell portion bulging upward, the plurality of lower holes are formed in the central spherical shell portion, and the plurality of upper holes are formed by the heating. An absorption type refrigerating apparatus, which is formed on an upper part of an outer periphery of a container.