JPH0355753B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a generator for a lithium monobromide water cooler/heater used in an air conditioner or the like.

As shown in Figs. 1 and 2, a conventional generator of this type has a combustion chamber 2 with a combustor 1 attached to the side thereof, and a combustion chamber 2 that is located almost vertically on the downstream side of this combustion chamber 2, that is, on the exhaust gas discharge side. , a group of evaporation tubes 3 arranged in a staggered manner, a liquid chamber 4 surrounding the combustion chamber 2 and having a solution outlet 6, and a solution inlet 7 and a solution inlet 7 integrally formed on the liquid chamber 4. It is composed of a gas-liquid separation chamber 5 having a refrigerant vapor outlet 8.

In the evaporative gas having the above structure, the combustion gas generated in the combustor 1 exchanges heat with the wall surface of the liquid chamber 4 by radiation and convection, and then exchanges heat with the evaporator tube group 3 mainly by convection. On the other hand, the solution is heated on the wall surface of the liquid chamber 4 and the evaporation tube group 3, generates refrigerant vapor, and flows into the gas-liquid separation chamber 5 as a gas-liquid two-phase upward flow, where it is separated into refrigerant vapor and solution. separated.
One of the refrigerant vapors flows out from the refrigerant vapor outlet 8 , the other refrigerant vapor generated and concentrated solution flows out from the solution outlet 6 , and the diluted solution flows in from the solution inlet 7 .

In such a generator, when the combustion gas flows from the combustion chamber 2 into the evaporator tube group 3, the adjacent evaporator tubes 3 in the first row in the evaporator tube group 3 as shown in FIG.
The flow rate is increased through the gap 9 between the combustion gases a and 3a, and the central portion having the maximum flow rate of the combustion gas directly collides with the front surface _3b1 of the second row of evaporation tubes 3b. For this reason, the front surface portion _3b1 becomes a stagnation portion, which increases the heat transfer coefficient and generates the maximum heat flow velocity, which not only causes local overheating, but also accelerates the progress of corrosion. Therefore, the life of the equipment will be shortened, the amount of non-condensable gas generated will increase, and the heat transfer coefficient of the condenser and absorber may decrease.

In order to eliminate the above-mentioned drawbacks, the conventional evaporator tubes 3a, 3a have had their gaps 9 enlarged to reduce the flow velocity of the combustion gas, which may lead to an increase in the size of the equipment. The disadvantage of increasing the size of such equipment is that the overall gas flow rate is reduced, and the heat transfer coefficient of the evaporator tube is reduced, so the heat transfer area must be increased, making the generator even larger.

In view of the above, an object of the present invention is to provide a generator for an absorption type water chiller/heater that is suitable for preventing local overheating of a group of evaporator tubes, increasing the overall average heat flow velocity, and achieving downsizing. .

The above object is achieved by offsetting the center of the evaporator tubes in the second row facing the gap with respect to the center line of the gap between adjacent evaporator tubes in the first row in the evaporator tube group. Ru.

With the above configuration, the combustion gas, which has been throttled and accelerated by the gap between adjacent evaporator tubes in the first row, directly collides with the off-center front surface of the evaporator tubes in the second row, resulting in stagnation. This prevents local overheating.

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

In Fig. 4, 1 is a combustor attached to the side of the combustion chamber 2, and 3 is a group of evaporator tubes arranged almost vertically in a staggered manner on the downstream side of the combustion chamber 2, that is, on the exhaust gas discharge side. As shown in FIG. 5, the evaporator tube group 3 includes evaporator tubes facing the gap 9 in the second row with respect to the center line A of the gap 9 between adjacent evaporator tubes 3a, 3a in the first row. It is arranged so that the center O of 3b is offset by a distance a in one direction (upward in the figure). The distance a is set to satisfy the following conditions.

S/2<a<D-S/2 (D: diameter of evaporation tube 3b) ...(1) Since the other structures are the same as the conventional example shown in FIGS. 1 and 2, the explanation and drawings are Omitted.

Since the present embodiment is configured as described above, the combustion gas is throttled when flowing through the gap 9 between the adjacent evaporator tubes 3a in the first row, and the flow velocity increases. This accelerated combustion gas directly collides with the front part 3b ₂ of the second row of evaporator tubes 3b, which is shifted by a distance a from the front central part 3b ₁ , so that no stagnation occurs and local overheating is prevented. , it is possible to prevent a decrease in the overall average heat transfer coefficient.

For example, when the solution temperature is about 150°C and the temperature of the combustion gas flowing into the evaporator tube group 3 is about 1000°C, in the conventional example (Fig. 3), the front central part 3b ₁ of the evaporator tube 3b in the second row The temperature is 30 to 50°C higher than the solution temperature, reaching 180°C, which is the limit temperature for corrosion progression.
On the other hand, according to the present embodiment (FIGS. 4 and 5), the front surface portion 3b ₂ is shifted from the front center portion 3b ₁ of the evaporation tube 3b.
The temperature of is only about 20°C higher than the solution temperature. As a result, a large amount of non-condensable gas is generated, and the temperature of the front section _3b2 is kept lower than 180°C, which is the limit temperature at which corrosion begins to rapidly progress, so overheating of the front section _3b2 is prevented. It can be prevented.

In another embodiment shown in FIG. 6, by moving the second row of evaporation tubes 3b to the center, the evaporation tubes 3b
The difference from the embodiment shown in FIG. 4 is that the center O of the evaporators 3a, 3a in the first row is shifted from the center line A of the opposing gap in the gap 9 between the adjacent evaporators 3a, 3a. Since the structure is the same, the explanation will be omitted.

With this configuration, the combustion gas whose flow velocity has been increased by being throttled in the gap 9 between the phosphor-containing evaporator tubes 3a in the first row is removed from the center of the front surface of the evaporator tubes 3b in the second row. Since it directly collides with the affected area, no stagnation occurs, which prevents local overheating and reduces the overall average heat transfer coefficient.

In the above embodiment, each tube 3a, 3b of the evaporation tube group 3
. . . used the same diameter, but in the other embodiment shown in FIG. By using a
b is arranged such that the center thereof is shifted from the center line of the gap 9 between adjacent evaporation tubes 3a, 3a in the first row. According to this embodiment configured in this way, it not only exhibits the same effect as the above embodiment, but also has a larger diameter of the second row of evaporator tubes 3b, so the heat transfer coefficient at the front surface is higher than that of thin evaporation tubes. This has the effect of further preventing local overheating.

As explained above, according to the present invention, the combustion gas, which has been throttled and accelerated by the gap between adjacent evaporator tubes in the first row, is directly directed to the front surface of the evaporator tubes in the second row, which is offset from the center. Because of the collision, it is possible to prevent the occurrence of stagnation, prevent local overheating, and increase the overall average heat flow rate, making it possible to downsize the generator.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a generator of a conventional absorption type water chiller/heater, FIG. 2 is a cross-sectional view taken along the - line in FIG. 1, and FIG. 3 is a diagram explaining the arrangement of the evaporation tubes in FIG. FIG. 4 is a cross-sectional view showing one embodiment of the generator of the absorption type water chiller/heater of the present invention, FIG. 5 is a diagram explaining the arrangement of the evaporation tubes of the same embodiment, and FIGS. FIG. 7 is a cross-sectional view showing another embodiment according to the present invention. 1... Combustor, 2... Combustion chamber, 3... Evaporator tube group, 3a, 3b... Evaporator tube, 9... Gap.

Claims (1)

[Claims] 1. A combustion chamber having a combustor, a group of evaporator tubes arranged in a staggered manner on the downstream side of the combustion chamber, a liquid chamber surrounding the combustion chamber, and an air chamber provided above the liquid chamber. In the generator consisting of a liquid separation chamber, the center of the second row of evaporation tubes facing the gap is offset with respect to the center line of the gap between adjacent evaporation tubes in the first row in the evaporation tube group. This is an absorption type water chiller/heater generator that is characterized by: 2. Let S be the gap between adjacent evaporator tubes in the first row in the evaporator tube group, D be the diameter of the evaporator tube in the second row, and a be the distance between the center of this evaporator tube and the center line of the gap. , the distance a is set to satisfy S/2<a<D-S/2, The generator for an absorption type water chiller/heater according to claim 1.