JPH0446340B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a direct-fired dual-effect absorption chiller/heater,
In particular, the present invention relates to a water chiller/heater suitable for improving the cooling coefficient of performance.

[Conventional technology]

FIG. 2 shows a system diagram of a conventional direct-fired dual-effect absorption chiller/heater. In FIG. 2, a high temperature regenerator 1 heats a dilute solution using a heating source 2, and sends an intermediate concentration solution and high temperature, high pressure superheated steam to a separator 3. Separator 3 separates refrigerant vapor and intermediate concentrated solution. The refrigerant vapor is sent to the low temperature regenerator 4 via the steam pipe, and the intermediate concentration solution is sent to the high temperature solution heat exchanger 11 via the liquid feed pipe. The intermediate concentration solution entering the high temperature solution heat exchanger 11 exchanges heat with the dilute solution sent to the high temperature regenerator 1 to warm the dilute solution, and then is sent to the low temperature regenerator 4 via the outlet pipe.

The refrigerant vapor that has entered the low-temperature regenerator 4 heats the intermediate concentration solution from the high-temperature heat exchanger 11, and then is led to the condenser 5 through an outlet pipe. In addition, low temperature regenerator 4
The intermediate concentration solution in the tank becomes a concentrated solution and refrigerant vapor by heating, and the refrigerant vapor is led to the condenser 5 through the vapor pipe. Meanwhile, the concentrated solution is led to the low temperature solution heat exchanger 10.

Now, the refrigerant vapor that has entered the low-temperature regenerator 4 is condensed into a condensate liquid, and is led to the condenser 5 via the outlet pipe. The liquid is cooled by the evaporator 7 and distributed through the distribution pipe into the low-pressure evaporator 7.

The liquid refrigerant dispersed in the evaporator 7
Inside, the cooling water flowing through the cold water heat exchanger 8 is cooled and evaporated, and flows into the absorber 9.
On the other hand, the concentrated solution led from the low temperature regenerator 4 to the low temperature solution heat exchanger 10 is cooled by exchanging heat with the dilute solution pumped to the low temperature solution heat exchanger 10 by the circulation pump 17, and then absorbed. It is dispersed in the container 9.

The concentrated solution spread in the absorber 9 is cooled by the cooling water heat exchanger 6 and absorbs the refrigerant vapor flowing from the evaporator 7 to become a dilute solution. This diluted solution is sucked by the circulation pump 17 via the return pipe 18, and the low temperature solution heat exchanger 10,
High temperature regenerator 1 again via high temperature solution heat exchanger 11
sent to. Thereafter, operations similar to those described above are repeated.

In this way, in the conventional dual-effect absorption chiller/heater, during cooling operation, the high-temperature, high-pressure superheated steam generated in the high-temperature regenerator 1 is used as a heating source for the low-temperature regenerator 4, thereby increasing the cooling performance coefficient. We are trying to improve the quality of our products.

[Problem that the invention seeks to solve]

In the above-mentioned conventional hot and cold water machine, the superheated steam generated in the high temperature regenerator 1 enters the low temperature regenerator 4 under the pressure state (600 to 700 mmHg) in the high temperature regenerator 1. on the other hand,
The temperature of the intermediate concentrated solution from the high-temperature regenerator 1 is lowered in a high-temperature solution heat exchanger, and the pressure is reduced in a low-temperature regenerator 4 to a pressure sufficient to remove the latent heat of superheated steam and condense it. Thus, the refrigerant vapor that serves as a heating source for the low-temperature regenerator 4 is condensed at a pressure of 600 to 700 mmHg, and enters the condenser 5 from the low-temperature regenerator 4 as a high-temperature condensed refrigerant of 90 to 100°C. In order to cool the refrigerant in such a state to the saturation temperature of 40 to 45° C. in the condenser 5, the sensible heat it possesses is wastefully discharged into the outside air by the cooling water.

Therefore, an object of the present invention is to provide a dual-effect water chiller/heater that can improve the cooling coefficient of performance by efficiently recovering heat.

[Means for solving problems]

In order to solve the above-mentioned problems, the present invention provides a direct-fired dual-effect absorption chiller/heater that uses heat exchange between the high-temperature condensed refrigerant from the low-temperature regenerator and the combustion air taken in from the outside. An air preheater is provided between a low temperature regenerator and a condenser for preheating, and the condensed refrigerant is transferred to the low temperature regenerator by heat exchange between the condensed refrigerant from the air preheater and the exhaust gas from the heating source. an exhaust gas heat exchanger installed in the exhaust gas passage for heating; and a steam ejector installed upstream of the low-temperature regenerator to draw refrigerant vapor from the air preheater using the high-temperature refrigerant vapor from the high-temperature regenerator as a driving source. It is characterized by having the following.

[Effect]

According to the present invention having the above configuration, the refrigerant vapor used as a heating source in the low-temperature regenerator becomes a high-temperature condensed refrigerant and enters the air preheater. The air preheater exchanges heat with the high-temperature condensed refrigerant and the combustion air taken in by a blower or the like to lower the temperature of the high-temperature condensed refrigerant. On the other hand, the combustion air reaches a high temperature and causes a combustion reaction with the fuel at the heating source. The condensed refrigerant, now at a low temperature, is reduced in pressure and sent to the condenser, but a portion of it is sucked from the outlet side of the air preheater by the action of the steam ejector and sent to the exhaust gas heat exchanger.
In this exhaust gas heat exchanger, heat exchange is performed between the drawn-in low-temperature, low-pressure condensed refrigerant and the high-temperature exhaust gas in the exhaust gas path. At this time, since the condensed refrigerant has a low pressure and a low temperature, the high temperature exhaust gas can be lowered to a low temperature, and even a part of the latent heat of the water vapor in the exhaust gas can be taken. Therefore, by using this amount of heat again as a heating source for the low-temperature regenerator, the amount of refrigerant generated in the low-temperature regenerator can be increased. By recovering heat in this way, the overall efficiency can be increased.

〔Example〕

Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a system diagram of a direct-fired dual-effect absorption chiller/heater according to the present invention. In FIG. 1, the same parts as in FIG. 2 are designated by the same reference numerals, and the description of FIG. 2 will be omitted here.

The main differences between FIG. 1 and FIG. 2 are as follows. That is, an air preheater 13 is provided between the low temperature regenerator 4 and the condenser 5, and the exhaust gas path 12
An exhaust gas heat exchanger 16 is provided therein, and a steam ejector 15 is provided between the separator 3 and the low-temperature regenerator 4.

The air preheater 13 exchanges heat between the high-temperature condensed refrigerant from the low-temperature regenerator 4 and the combustion air 14 taken in from outside by a blower or the like, and uses the high-temperature condensed refrigerant as a heating source to generate the combustion air 14. This is for preheating. The preheated combustion air 14 is sent to the burner 2, which is a heating source, through piping, and subjected to a combustion reaction with fuel. On the other hand, the outlet pipe of the air preheater 13 is branched in a direction different from the pipe heading toward the condenser 5, and is connected to the inlet side of the exhaust gas heat exchanger 16 via a pipe 19.

The exhaust gas heat exchanger 16 exchanges heat between the condensed refrigerant drawn from the air preheater 13 and the exhaust gas sucked through the pipe 19. Its outlet side is connected to a steam ejector 15.

The steam ejector uses high-temperature refrigerant vapor from the separator 3 as a driving source to suck condensed refrigerant from the air preheater 13, and also sucks high-temperature refrigerant vapor generated in the exhaust gas heat exchanger 16 as a heating source for the low-temperature regenerator 4. belongs to.

Next, the effect will be explained. Note that the effects related to the same parts as in Figure 2 have been described above, so they will be omitted here.
Parts related to the present invention will be explained.

The refrigerant vapor used as a heating source in the low-temperature regenerator 4 becomes a high-temperature condensed refrigerant and passes through the air preheater 13.
to go into. In the air preheater 13, the high-temperature condensed refrigerant exchanges heat with the combustion air 14 taken in by a blower or the like to lower the temperature of the high-temperature condensed refrigerant, while the combustion air 14A becomes high temperature and is heated in the burner 2 serving as the heating source. Causes a combustion reaction with fuel. The condensed refrigerant, now at a low temperature, is depressurized and sent to the condenser 5,
A part of it is sucked from the outlet side of the air preheater 13 by the action of the steam ejector 15, and is transferred to the exhaust gas heat exchanger 1.
Sent to 6. In the exhaust gas heat exchanger 16, heat exchange is performed between the drawn-in low-temperature, low-pressure condensed refrigerant and the high-temperature exhaust gas in the exhaust gas path 12. At this time, since the condensed refrigerant has a low pressure and a low temperature, the high temperature exhaust gas can be lowered to a low temperature, and even a part of the latent heat of the water vapor in the exhaust gas can be taken. Therefore, by using this amount of heat again as a heating source for the low-temperature regenerator 4, the amount of refrigerant generated in the low-temperature regenerator 4 can be increased. By recovering heat in this way, the overall efficiency can be increased.

The above action will be specifically explained using numerical values as follows. Assuming that the temperature of the condensed refrigerant from the low-temperature regenerator 4 is 100°C, the temperature of the outlet refrigerant becomes 40°C due to the heat exchange action in the air preheater 13.
Due to this temperature drop, per unit weight of refrigerant
A calorific value of 60Kcal/Kg is obtained in 14A of combustion air. 2.5Kg/h per 1Rt in high temperature regenerator 1
Assuming that Rt refrigerant is generated, 2.5 per Rt
×60=150Kcal/h・Rt of heat can be obtained. Also, when the exhaust gas temperature is lowered from 200℃ to 50℃ in the exhaust gas heat exchanger 16, it varies depending on the fuel used, but in the case of propane gas, 1Rt
It is possible to obtain 14.4% of the latent heat of water vapor in the exhaust gas as a sensible heat amount of 185Kcal/h・Rt from the exhaust gas.
Therefore, a latent heat amount of 28 Kcal/h・Rt can be obtained. As a result, the amount of heat obtained from the exhaust gas in the exhaust gas heat exchanger 16 is 185 + 28 = 1 Rt.
It becomes 213Kcal/h・Rt. The aforementioned air preheater 13
When combined with , the amount of heat obtained per 1Rt is
150+213=363Kcal/h・Rt, this value is approximately
This means a 10% increase in efficiency.

〔Effect of the invention〕

As described above, according to the absorption chiller/heater of the present invention, by providing an air preheater, an exhaust gas heat exchanger, and a steam ejector, heat that was conventionally wasted wasted into the atmosphere can be efficiently recovered. It is possible,
It is possible to improve the efficiency of the system and improve the cooling coefficient of performance.

[Brief explanation of drawings]

FIG. 1 is a system diagram of a dual-effect absorption chiller/heater according to the present invention, and FIG. 2 is a system diagram of a conventional dual-effect absorption chiller/heater. 1... High temperature regenerator, 2... Burner, 3... Separator, 4... Low temperature regenerator, 5... Condenser, 6... Cooling water heat exchanger, 7... Evaporator, 8... Cold temperature Water heat exchanger, 9... Absorber, 10... Low temperature solution heat exchanger, 11... High temperature solution heat exchanger, 12... Exhaust gas path, 13... Air preheater, 14... Combustion air,
10A... Preheated combustion air, 15... Steam ejector, 16... Exhaust gas heat exchanger, 17... Circulation pump, 18... Return piping, 19... Piping.

Claims (1)

[Scope of Claims] 1. In a direct-fired dual-effect absorption chiller/heater, the combustion air is heated to a low temperature in order to preheat the combustion air by heat exchange between the high-temperature condensed refrigerant from the low-temperature regenerator and the combustion air taken in from the outside. an air preheater provided between the regenerator and the condenser; and an exhaust gas path for generating refrigerant vapor to the low temperature regenerator by heat exchange between the condensed refrigerant from the air preheater and the exhaust gas from the heating source. and a steam ejector provided at a stage upstream of the low-temperature regenerator to suck refrigerant vapor from the air preheater using high-temperature refrigerant vapor from the high-temperature regenerator as a driving source. A direct-fired dual-effect absorption chiller/heater characterized by: