JPH05332633A - Composite freezer device - Google Patents

Abstract

PURPOSE:To construct a heat pump system having a high thermal efficiency. CONSTITUTION:Vapor generated at the first generator 1 is passed to a heater unit 2 of the second generator 11, thereafter the vapor is guided to the first evaporator 3, an external driving heat source 20 is applied as a driving heat source for the first generator 1, and the first thermal medium circulation passage 23 circulating between the first absorber unit 4 and the second generator 11. Heat of the thermal medium heated by the first absorber unit 4 and passing through the first thermal medium circulation passage 23 and heat generated by the first generator 1 and retained by the vapor transferred to the heater unit 2 are applied as a driving heat source for the second generator 11. At least one of the second condensor 12 and the second absorber unit 14 and the first evaporator 3 are connected by the second thermal medium circulation passage 24. The vapor applied as a heating source for the first evaporator 3 and generated by the second evaporator 3 is increased in its pressure by a mechanical compressor 31 and its condensing is carried out by the second absorbing unit 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combined refrigeration system, and more particularly to a double-effect absorption heat pump in which two absorption heat pump systems for the first effect and the second effect are combined, and further to a mechanical compressor. The present invention relates to a combined refrigeration system.

[0002]

2. Description of the Related Art With regard to this type of absorption heat pump, there are remarkable improvements in the system as well as improvements in the equipment. A typical example thereof is a double-effect heat pump.

The most efficient way of operating this double-effect heat pump system is to transfer the heat of the first condenser and the heat of the first absorber to the first generator. With such a configuration, by taking heat from the second condenser and the second absorber, it is possible to take out the heat quantity 4Q, which is four times the heat quantity Q given to the first generator, to the outside.

In order to establish this relationship, when the same effector is used for the first effect and the second effect, the temperatures of the first evaporator and the second evaporator are almost the same. Needs to increase the temperature of the first generator and increase the temperatures of the first condenser and the first absorber.

[0005]

However, in the case where the refrigerant and the absorbent are water-lithium bromide type, it can be established by increasing the temperature and concentration of the first generator, but the temperature in this case is 180 It becomes more than ℃ and the corrosion progresses and it cannot be put to practical use.

In the case of a water-ammonia system, it is necessary to operate under conditions of high temperature and low ammonia concentration, a high pressure vessel is required, and the equipment cost increases, and
For stable operation, reflux operation is required in the first generator in order to keep the generated vapor concentration constant. As a result, the thermal efficiency decreases.

[0007] Therefore, an object of the present invention is to solve the apparatus limitation and to construct a heat pump system having high thermal efficiency.

[0008]

SUMMARY OF THE INVENTION The above-mentioned problem is that the first generator, the first evaporator and the first absorber constitute a first absorption heat pump using a refrigerant and an absorbent, respectively, and a second generator. , A second condenser, a second evaporator, and a second absorber constitute a second absorption heat pump, and the vapor generated in the first generator is passed through the heater of the second generator,
The condensate is guided to the first evaporator, the external drive heat source is used as the drive heat source of the first generator, and a first heat medium circulation path that circulates between the first absorber and the second generator is configured. Second generation of heat of the heat medium heated in the first absorber and passing through the first heat medium circulation path, and heat of the vapor generated in the first generator and transferred to the heater of the second generator A heat source for driving the reactor, at least one of the second condenser and the second absorber, and the first
A second heat medium circulation path is connected to the evaporator to serve as a heating source for the first evaporator. Vapor generated in the second evaporator is boosted by a mechanical compressor and condensed in a second absorber. It can be solved by trying.

In this case, in the second heat medium circulation path, the heat medium passes through the second absorber and the second condenser in this order, and then the first heat medium.
It can be configured to reach the evaporator.

On the other hand, using a refrigerant and an absorbent, respectively,
The first generator, the first evaporator, and the first absorber constitute a first absorption heat pump, and the second generator, the second condenser, and the second
A second absorption heat pump is constituted by the evaporator and the second absorber, and the vapor generated by the first generator is converted into the second heat pump.
While passing through the heater of the generator, lead the condensate to the first evaporator, the external drive heat source as the drive heat source of the first generator,
A first heat medium circulation path that circulates between the first absorber and the second generator is configured, and heat of the heat medium that is heated by the first absorber and passes through the first heat medium circulation path, and the first heat medium circulation path. The heat of the vapor generated by the generator and transferred to the heater of the second generator is used as the driving heat source of the second generator, and the third heat transfer medium is provided between the second evaporator and the first evaporator. It is also possible to solve the problem by connecting with a circulation path and using it as a heating source for the first evaporator, and increasing the vapor generated in the second evaporator by a mechanical compressor to condense it in the second absorber. Here, the second absorber and the second condenser may be connected by a fourth heat medium circulation path. Further, the refrigerant and the absorbent in the first effect of the present invention are water-lithium bromide or TFE (tetrafluoroethylene) -E181 (tetraethylene glycol) having no vapor-liquid equilibrium.
Dimethyl ether), and the refrigerant and the absorbent in the second effect are water-ammonia or R1 in which the refrigerant has compressibility.
34a-E181.

[0011]

In the first aspect of the present invention, the absorption heat pump for the first effect and the absorption heat pump for the second effect are combined, and the heat of the second condenser and the second absorber is transferred to the first evaporator. Since it is used for heating, the operating temperature of the first absorber can be increased. Further, since the vapor generated in the second evaporator is compressed and pressurized by the mechanical compressor and guided to the second absorber, the operating pressure of the second absorber can be increased, and the second pressure is correspondingly increased. The operating temperature of the generator can be lowered, so that heat can be easily transferred from the first absorber having a high operating temperature to the second generator having a low operating temperature.

On the other hand, even if the operating temperature of the second generator is -40 ° C. (in the case of water-ammonia system), the compression ratio by the mechanical compressor is selected so that the condenser can be operated like a normal refrigerator. Since the refrigeration system can be constructed by increasing the pressure up to the intermediate pressure of the absorber without pressurizing to the pressure of, the power consumption of the mechanical compressor according to the present invention is the mechanical power of the refrigerator used in the conventional refrigeration system. Compared to the power consumption of the compressor,
It becomes about 1/2 to 1/3. Moreover, by using the mechanical compressor, the pressure of the second evaporator can be freely adjusted, and therefore the temperature of the second evaporator can also be freely adjusted within the range of -40 ° C to 0 ° C.

In the present invention, as another advantage of using the mechanical compressor, as in the second aspect of the present invention, as described above, the operating temperature of the second generator can be lowered, so that the medium temperature water is used. (About 50 to 60 ° C.) is supplied to the second generator, evaporation operation is performed in the first evaporator, and cold water is produced in the third circulation path between the first evaporator and the second evaporator. It can be carried out efficiently, and the coefficient of performance for obtaining cold water at 0 ° C to 10 ° C is 2.1 to 2.6, which is extremely high.

On the other hand, since steam, combustion gas or the like can be used as the heat source of the first generator, the coefficient of performance in the case of producing brine at -30 ° C. is 2.1, which is required for this. 47% of the energy is electric energy for driving the mechanical compressor, and the remaining 53% is heat energy for heat input to the first generator, both of which are more efficient than conventional absorption refrigerators. Target.

[0015]

EXAMPLES The present invention will be described in more detail by way of examples with reference to FIG. The first generator 1, the first evaporator 3, and the first absorber 4 constitute a first absorption heat pump, respectively using a refrigerant and an absorbent, and a second generator 11, a second condenser 12, and a second The evaporator 13 and the second absorber 14 constitute a second absorption heat pump. Here, a water-lithium bromide system can be used in the first effect, and a water-ammonia system can be used in the second effect.

The first generator 1 includes a suitable external drive heat source 2
0 is given from the outside and the vapor generated in the first generator 1 is passed through the supply line 21 to the heater 2 of the second generator 11 and then the condensate there is guided to the first evaporator 3. Is configured. Here, the heater 2 operates as a first condenser.

Further, a first heat medium circulation passage 23, which is circulated by a pump 22 between the first absorber 4 and the second generator 11, is constructed, and is heated by the first absorber 4 to circulate the first heat medium. The heat medium passing through the passage 23 and the heat of the vapor generated in the first generator 1 are used as the driving heat source of the second generator 11.

The vapor from the first generator 1 to the second generator 11 is condensed in the heater 2 and gives heat to the second effect system, and the condensed liquid condensed here is supplied to the first evaporator 3. It is guided and evaporated by the heat medium (heated water in this case) passing through the second heat medium circulation passage 24, which will be described later, and the evaporation vapor is transferred to the pipe line 50.
Is guided to the first absorber 4 via.

Between the first absorber 4 and the first generator 1,
A supply line 26 for the concentrated liquid due to the concentration in the first generator 1 by the circulation pump 25 and a return line 27 for the diluted liquid due to the absorption and condensation constitute a first exchange line. In this circulation exchange process, heat exchange between the concentrated liquid and the diluted liquid is performed by the first heat exchanger 28. Therefore, the vapor introduced into the first absorber 4 via the line 50 comes into contact with the concentrated liquid from the first generator 1 to be absorbed and condensed,
The condensation heat at this time is used as a heating heat source of the second generator 11.

The same applies to the second effect heat pump which is in charge of the low temperature side, and the evaporated refrigerant (in this case, ammonia vapor in this case) in the second generator 11 driven by receiving heat from the heater 2 and the first absorber 4 is driven. ) Is supplied to the second condenser 12 by the supply line 50, and the condensed liquid therein is guided to the second evaporator 13 by the supply line 30. Second evaporator 1
In 3, the heat absorbing source 38 is supplied and the ammonia vapor is evaporated. The evaporated ammonia vapor is compressed and pressurized by the mechanical compressor 31 and supplied to the second absorber 14 through the supply pipe 32. A circulation pump 33 is provided between the second absorber 14 and the second generator 11.
The concentrated liquid supply conduit 34 and the diluted liquid return conduit 35 constitute a second exchange passage. In this circulation process, heat exchange between the concentrated liquid and the dilute liquid is performed by the second heat exchanger 36.

On the other hand, the second absorber 14, the second condenser 12,
A second heat medium circulation path 24 connected in this order to the first evaporator 3 is configured. 37 is a pump for the circulation. In the second heat medium circulation path 24, the second absorber 1
Cooling pipe 14a at 4 and cooling pipe 1 at the second condenser 12
The heat is taken by the portion 2a and given to the first evaporator 3 for the first effect. If there is an excess, the heat exchanger 39
It is designed to be taken out as warm water 40 or the like.

In the case of the first embodiment, when heat is applied to the first evaporator 3, it may be applied from either the second absorber 14 or the second condenser 12.

In such a system, by appropriately selecting the temperature and pressure in the second evaporator 13 in the second effect of the water-ammonia system, the evaporation temperature there is -40 ° C to 0 ° C. Low temperatures in the range can be obtained.

By the way, conventionally, in the water-lithium bromide type absorption refrigerator, it is not possible to obtain a low temperature of 0 ° C. or lower, and in the water-ammonia system, there is a vapor-liquid equilibrium, so that the reflux operation is performed as described above. It was necessary and had poor thermal efficiency.

However, in constructing the second effect heat pump, since the refrigerant (ammonia) is compressed and boosted by the mechanical compressor 31, the second absorber 14 is used.
The operating pressure on the 2nd generator 11 correspondingly increases.
Temperature drops. Therefore, the second effect heat pump can be driven without the need for the reflux operation in the second generator, and the operation with high thermal efficiency can be performed. Then, the heat absorption source 38 that has passed through the heat transfer tube 13a of the second evaporator 13 finally has the low temperature heat source 3 in the range of -40 ° C to 0 ° C.
8a.

The above-mentioned mechanical compressor 31 can be driven by an internal combustion engine such as a gas engine, a gas turbine or a diesel engine. In this case, the heat of the exhaust gas is supplied to the first generator. By doing so, the operating efficiency (coefficient of performance) can be further increased.

In the present invention, the low temperature heat source 38a described above is used.
To obtain the low-temperature heat source 38a as cold water and obtain the hot water 40 of, for example, about 50 ° C. from the heat exchanger 39, thereby providing a heat pump for freezing or for producing hot / cold water. it can. When the mechanical compressor 31 is driven by the above-mentioned internal combustion engine, a highly efficient cogeneration system can be constructed.

Conventionally, for example, when the outside air temperature is about -5 to -20 ° C in a cold region, it is impossible to drive the absorption refrigerator using this heat, but the present invention According to the above, this is possible, and driving can be performed with a coefficient of performance of 2 or more.

In the present invention, for example, the coefficient of performance for obtaining hot water at 50 ° C. is 2.3, and the coefficient of performance for producing cold water at −20 ° C. is 1.3. Therefore, it is found that the coefficient of performance is higher than that of the conventional absorption refrigerator.

On the other hand, conventionally, in a factory or the like, 60 ° C.
The so-called medium-temperature water of a certain degree has a limited use in spite of its enormous amount, and in most cases it is currently discarded. Therefore, as shown in FIG.
The heat of the medium temperature water 41 at an intermediate temperature between the externally driven heat source 20 and the heat absorption source (heat absorption source passing through the third heat medium circulation path) is applied to the heater 4
By giving it via 2, the refrigerating capacity in the absorption heat pump of the second effect can be further enhanced.

In the example shown in FIG. 2, in the fourth heat medium circulation passage 45, the heat medium circulated by the circulation pump 37 is cooled in the cooling pipe 14a in the second absorber 14 and in the second condenser 12. The heat is taken away by the pipe 12a portion, and this heat is given as hot water 44 by the hot water heater 43 to be radiated to the outside. In addition, the third heat medium circulation path 46
In the above, the heat medium circulated by the circulation pump 47 passes through the cooling pipe 13 a in the second evaporator 13 and the first evaporator 3, and the cold water 49 is taken out by the heat exchanger 48.

Next, the effects of the present invention will be clarified by showing examples. (Embodiment 1) This embodiment 1 has a structure shown in FIG. 1, and is used as a refrigerant and an absorbent in the first effect, water-
Lithium bromide was used with water-ammonia in the second effect. As the driving heat source 20 from the outside, steam having a pressure (8 kgf / cm ² abs) is used, and the concentration, temperature and pressure in each device are as follows.

<First effect> Concentration (wt%) Temperature (° C) Pressure (mmHg) First generator 1 62 to 66 174 760 First condenser 2 Condensed water 100 760 First evaporator 3 Condensed water 40 55 1 Absorber 4 62 to 66 96 to 100 55 <Second effect> Concentration (wt%) Temperature (° C) Pressure (kgf / cm ² abs) Second generator 11 45 to 50 84 to 90 20.7 to 20.8 Second condensation Vessel 12 Drain 50 20.7 to 20.8 Second evaporator 13 Ammonia -10 3.08 to 3.10 Second absorber 14 45 to 50 89 to 90 6.0 to 6.2 On the other hand, as the intermediate compressor 31, a 250 KW screw type ammonia compressor (compression ratio) is used. 2.0-2.4, inhalation volume 4200-4600
kg / hr) was used. As a result, in the heat exchanger 39, water having an inlet temperature of 40 ° C can be heated to hot water having an outlet temperature of 50 to 52 ° C,
The total calorific value of the hot water was 3.26 × 10 ⁶ Kcal / hr. Second
The evaporation temperature in the evaporator was −10 ° C., and the production capacity of cold water 38a was 1.52 × 10 ⁶ Kcal / hr.

(Embodiment 2) This embodiment 2 has a structure shown in FIG. 2, and uses water-lithium bromide in the first effect and water-ammonia in the second effect as the refrigerant and the absorbent. I was there. As the driving heat source 20 from the outside, steam having a pressure of 10 kgf / cm ² abs, 8.54 × 10 ⁶ Kcal /
In addition to being supplied to the first generator 1 in hr, this was supplied to the second generator 11 at 7.0 × 10 ⁶ Kcal / hr in order to utilize the heat of the scrubber wastewater of the incinerator of the sewage treatment plant. The inlet temperature of the heater 42 is 75 ° C and the outlet temperature is 54 ° C. The temperature and pressure of each device are as follows.

[0035] <Second effect> Temperature (° C) Pressure (kgf / cm ² abs) Second generator 11 42 to 45 11.9 Second condenser 12 30 11.9 Second evaporator 13 7 5.6 Second absorber 14 30 to 36 6.7 On the other hand As the mechanical compressor 31, a 112 KW screw type ammonia compressor was used. As a result, 1 chilled water at 7 ℃
It was possible to obtain with a heat output of 8.0 × 10 ⁶ Kcal / hr. In this case, the coefficient of performance based on the calorific value is 2.1 based on the heat input standard excluding waste heat, and the capacity for cold water production is also high.

[0036]

As described above, according to the present invention, it is possible to construct a heat pump system having high thermal efficiency.

[Brief description of drawings]

FIG. 1 is a flow sheet of a first aspect of the present invention.

FIG. 2 is a flow sheet of a second aspect of the present invention.

[Explanation of symbols]

1 ... 1st generator, 2 ... heater (1st condenser), 3 ... 1st
Evaporator, 4 ... 1st absorber, 11 ... 2nd generator, 12 ... 2nd condenser, 13 ... 2nd evaporator, 14 ... 2nd absorber, 23
... 1st heat-medium circulation path, 24 ... 2nd heat-medium circulation path, 31 ... Mechanical compressor, 45 ... 4th heat-medium circulation path, 46 ... 3rd heat-medium circulation path.

Claims (5)

[Claims] 1. A first absorption heat pump comprising a first generator, a first evaporator, and a first absorber using a refrigerant and an absorbent, respectively, and a second generator, a second condenser, and a second condenser. Evaporator,
The second absorber constitutes a second absorption heat pump, the vapor generated in the first generator is passed through the heater of the second generator, and the condensate thereof is guided to the first evaporator so that an external drive heat source is provided. A first heat medium circulation path that circulates between the first absorber and the second generator is used as a driving heat source for the first generator, and the first heat medium circulation path is heated by the first absorber. The heat of the passing heat medium and the heat of the vapor generated in the first generator and transferred to the heater of the second generator are used as the driving heat source of the second generator, and the second condenser and the second absorber are used. At least one of the evaporators and the first evaporator are connected by a second heat medium circulation path to serve as a heating source for the first evaporator, and vapor generated in the second evaporator is pressurized by a mechanical compressor. A composite refrigeration system, characterized in that it is configured to condense in the second absorber. 2. The combined refrigerating apparatus according to claim 1, wherein in the second heat medium circulation path, the heat medium passes through the second absorber and the second condenser in this order and then reaches the first evaporator. 3. A first absorption heat pump comprising a first generator, a first evaporator, and a first absorber using a refrigerant and an absorbent, respectively, and a second generator, a second condenser, and a second condenser. Evaporator,
The second absorber constitutes a second absorption heat pump, the vapor generated in the first generator is passed through the heater of the second generator, and the condensate thereof is guided to the first evaporator so that an external drive heat source is provided. A first heat medium circulation path that circulates between the first absorber and the second generator is used as a driving heat source for the first generator, and the first heat medium circulation path is heated by the first absorber. The heat of the passing heat medium and the heat of the vapor generated in the first generator and transferred to the heater of the second generator are used as the driving heat source of the second generator, and the second evaporator and the first evaporator A third heat medium circulation path is connected to the reactor to serve as a heating source for the first evaporator, and the vapor generated in the second evaporator is pressurized by a mechanical compressor to be condensed in the second absorber. A composite refrigeration system characterized by having a configuration for achieving the above. 4. The combined refrigeration method according to claim 3, wherein the second absorber and the second condenser are connected by a fourth heat medium circulation path. 5. The refrigerant and absorbent in the first effect is water-lithium bromide or TFE-E181, and the second effect is
Water-ammonia or R1 is the refrigerant and absorbent in the effect.
34a-E181 is the combined refrigeration system according to claim 1 or 3.