JPS6152902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field> The present invention relates to an improvement of a refrigeration cycle equipped with a compressor, a condenser, an evaporator, and the like.

<Prior Art> FIG. 1 is a schematic diagram of a conventional refrigeration cycle of a vapor compression refrigerator, in which A shows a compressor, B shows a condenser, C shows a pressure reducing device, and D shows an evaporator.

In addition, Fig. 2 is a Mollier diagram of the refrigeration cycle shown in Fig. 1, and symbols a', b', c', and d' are the first
Symbols a, b, c, and d in the figure correspond to the states of the respective parts of the refrigeration cycle.

In the above refrigeration cycle, in this method, the refrigerant liquid and flash gas discharged from the pressure reducing device C are sent together to the evaporator D, but since the flash gas generally has a significantly large specific volume, it occupies most of the space inside the evaporator D. As a result, the ratio of the area in contact with the refrigerant liquid where evaporation occurs is small, resulting in a disadvantage that the performance is reduced. In addition, since the heat transfer of gases such as flash steam is very small, the heat exchange between evaporators 2 and 2 is poor, and the pressure loss in evaporator 2 and the piping from evaporator 2 to the compressor is large due to the flash gas. There was a drawback.

Here, a system has been proposed in which only liquid refrigerant is introduced into the evaporator by interposing a gas-liquid separator during the cycle, and gas-phase refrigerant is introduced into the suction side of the compressor. However, in this case, only liquid refrigerant is introduced into the evaporator, so the drawbacks caused by the flash gas mentioned above can be overcome, but since the liquid refrigerant introduced into the evaporator is within the saturated range, The latent heat of vaporization that could be taken from the air was not very large.

<Purpose> The present invention has been made in view of the above points, and an object of the present invention is to increase the refrigerating capacity by bringing the refrigerant introduced into the evaporator into a supercooled state.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to FIGS. 3 to 5.

FIG. 3 is a schematic diagram of a refrigeration cycle according to the present invention,
FIG. 4 is a detailed view of the jet device provided in the refrigeration cycle, and FIG. 5 is a Mollier diagram of the refrigeration cycle shown in FIG. 3.

In this FIG. 3, 1 is a compressor, 2 is a condenser provided on the discharge side of this compressor,
15 is an evaporator provided on the discharge side of this condenser. A is a gas-liquid separation supercooling circuit connected to the discharge side of this condenser, and this circuit A is connected to an ejector 3 connected to the condenser 2 on the inflow side and to the discharge side of this ejector 3. A gas-liquid separator 9 separates the gas-liquid two-phase refrigerant discharged from the ejector 3 into gas-phase refrigerant and liquid-phase refrigerant; a gas discharge passage 12 connected to the upper part of the separator 9 to introduce the refrigerant into the evaporator 15; 9 bottom 11 and evaporator 15
a liquid discharge passage 12 provided between the liquid refrigerant, a discharge passage 14 provided on the side of the separator 9 to derive a part of the liquid refrigerant in the liquid separator 9, and a discharge side of this discharge passage 14. A pressure reducing mechanism 13 such as a capillary tube connected to the refrigerant connected to the discharge side of the pressure reducing mechanism 13 and discharged from the pressure reducing mechanism 13 and the liquid refrigerant in the gas-liquid separator 9 exchange heat. Heat exchanger 7 installed in gas-liquid separator 7 and this heat exchanger 7
and a return path 16 for returning the refrigerant discharged from the ejector to the low pressure portion of the ejector 3.

As shown in FIG. 3, the ejector 3 is comprised of a nozzle 5 that ejects high-pressure refrigerant that has flowed in from the suction port 4 to reduce the pressure to a low pressure, and a low-pressure section 17 that is a space from which the refrigerant is ejected from the nozzle 5. A connection port 8 for connecting the return path 16 is provided above the low pressure section 17.

Now, the operation of the refrigeration cycle configured as described above will be explained with reference to the pi diagram shown in FIG.

First, high-temperature, high-pressure gas (a → b) discharged from the compressor 1 is condensed in the condenser 2 and becomes a liquid (b
→c). In this state, the refrigerant is in a gas-liquid mixed state at medium temperature. Next, this gas-liquid mixed refrigerant is transferred to the ejector 3.
The high-pressure refrigerant is ejected from the nozzle 5 through the suction port 4 to reduce the pressure (c-d), but in this state d, the refrigerant is affected by the suction effect of the ejector 3 (the pressure generated when the high-pressure refrigerant is reduced in pressure). The refrigerant in the state e (described later) is mixed with the refrigerant in the state e (described later), which is sucked through the connection port 8 by the suction effect based on the reduced energy (suction effect based on the reduced energy), and becomes the state f, and while passing through the low pressure section 17, the pressure increases slightly to become g. and is introduced into the gas-liquid separator 9.
The refrigerant in the state g introduced into the gas-liquid separator 9 is separated into a gas-phase refrigerant a and a liquid-phase refrigerant h, and the gas-phase refrigerant a is led out to the suction side of the compressor 1 through the gas discharge passage 12. Most of the liquid phase refrigerant h is discharged from the liquid discharge passage 11, and a portion is led out from the outlet 14 by the suction effect of the ejector 3. The refrigerant led out from this outlet 14 changes from the state h to the state j by passing through the pressure reducing mechanism 13, and at the same time as the pressure is reduced, the temperature decreases due to the pressure reduction, and the liquid refrigerant in the gas-liquid separator 9 It becomes a low-temperature, low-pressure refrigerant. This low-temperature, low-pressure refrigerant is transferred to the heat exchanger 7.
Here, it exchanges heat with the liquid refrigerant in the state h in the gas-liquid separator 7, and as a result, a part of the refrigerant passing through the heat exchanger 7 is vaporized by the heat exchange and becomes e. The temperature rises to h, while the others remain in the liquid state, and the vapor phase e and liquid phase h are introduced into the ejector 3 again in a mixed form. On the other hand, by being cooled, the liquid refrigerant h in the gas-liquid separator 9 is supercooled from the state h to the state i, and therefore the liquid refrigerant h discharged from the liquid discharge passage 11 is The refrigerant is discharged in this supercooled state i, and only this supercooled liquid refrigerant is introduced into the evaporator 15. The liquid phase refrigerant introduced into the evaporator 15 in this state of i is (i _a
-i _i ) It absorbs heat by kal and evaporates to become a gas phase refrigerant a, which is introduced into the compressor 1 again. The same operation is repeated below.

Therefore, if the cycle has the above configuration, the condenser 2
The gas-liquid mixed refrigerant drawn out from the refrigerant is depressurized in the ejector 3 and then separated into a gas-phase refrigerant and a liquid-phase refrigerant in the gas-liquid separator 9, of which only the liquid-phase refrigerant is introduced into the evaporator 15. Therefore, there is no adverse effect of heat exchange due to the gas phase heat medium in the evaporator 15, and the heat exchange rate in the evaporator 15 can be dramatically improved. Moreover, the liquid refrigerant introduced into the evaporator 15 is supercooled using a part of the refrigerant drawn out from the gas-liquid separator 9, so that the refrigerant introduced into the evaporator 15 is i _a - i _i During heat exchange in the evaporator 15, more heat ((i _{a −i} (i _a − i _i ) > (i _a ′ − i _d ′) [see Figures 2 and 5]), and as a result, the refrigeration capacity increases. It turns out. Furthermore, the refrigerant that cools the gas-liquid separator 15 uses the energy when the high-pressure refrigerant discharged from the condenser is reduced to a low pressure, that is, the refrigerant is extracted using the high-pressure energy of the refrigerant ( (ejector effect), no extra burden is placed on the compressor 1 for this cooling, and there is no need to take the trouble to use a compressor with a large capacity. Furthermore,
The amount of supercooled circulating refrigerant introduced into the evaporator 15 is determined by the gas-phase refrigerant being discharged from the gas discharge passage 12 in the gas-liquid separator 9, and a portion of the liquid refrigerant being discharged from the depressurization mechanism 13 through the discharge passage 14. Since it is led out to the heat exchanger 7 and supplied to the ejector 3 again, the amount of circulation is reduced compared to the conventional system in which the subcooling circuit A is not provided. Therefore, the liquid discharge path 11
Since the piping resistance proportional to the flow rate can be reduced, the pressure loss in the liquid discharge path 11 of the refrigerant led from the gas-liquid separator 9 to the evaporator 15 can be reduced, and the evaporation capacity can be improved. and improve the coefficient of performance. Therefore, in the cycle of this embodiment, for example, as in a separate air conditioner, only the evaporator 15 is placed indoors as an indoor unit, and the rest are placed outdoors as an outdoor unit, and they are connected by a relatively long liquid discharge path 11. This can greatly contribute to reducing pressure loss between indoor and outdoor units.

<Effects> According to the present invention, the compressor, condenser,
In a refrigeration cycle in which evaporators are connected in sequence, an ejector with a condenser connected to the inflow side, a gas-liquid separator connected to the discharge side of this ejector, and a gas-liquid separator connected to the discharge side of this ejector are installed between the condenser and the evaporator. a gas discharge passage for introducing the gas phase refrigerant in the liquid separator to the compressor inlet side; a liquid discharge passage for introducing the liquid refrigerant in the gas-liquid separator to the evaporator; and a liquid refrigerant in the gas-liquid separator. a depressurization mechanism connected to the discharge side of the depressurization mechanism, and a depressurization mechanism connected to the discharge side of the depressurization mechanism to conduct heat exchange with the liquid refrigerant in the gas-liquid separator. A gas-liquid separation supercooling circuit is provided, which consists of a heat exchanger disposed in the heat exchanger and a return path for reintroducing the refrigerant discharged from the heat exchanger to the ejector, so that the refrigerant discharged from the condenser is By reducing the pressure of the refrigerant and separating the refrigerant into gas and liquid, only the liquid refrigerant can be introduced into the evaporator in a supercooled state.

Therefore, since there is no flash gas in the evaporator, the heat exchange rate in the evaporator increases, and
Because the refrigerant introduced into the evaporator is supercooled, more heat can be taken from the atmosphere than in the conventional cycle in which refrigerant that is not supercooled and is in the saturated region is introduced into the evaporator. As a result, in conjunction with the improvement in the heat exchange rate described above, the refrigerating capacity of the evaporator can be dramatically improved. Moreover, when supercooling the refrigerant, the refrigerant in the gas-liquid separator is drawn out using the high-pressure energy of the refrigerant, and the drawn-out refrigerant is further reduced in pressure to lower its temperature and separated into gas and liquid. Since the refrigerant in the container 9 is subcooled, no extra burden is placed on the compressor even if a subcooling circuit is inserted in the circuit.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional refrigeration cycle for a vapor compressor, Fig. 2 is a Moller diagram of the refrigeration cycle of Fig. 1, Fig. 3 is a schematic diagram of a refrigeration cycle according to the present invention, and Fig. 4 is a schematic diagram of a refrigeration cycle according to the present invention. FIG. 5 is a detailed view of the jet device provided in the refrigeration cycle, and is a Mollier diagram of the refrigeration cycle shown in FIG. 3. 1: Compressor, 2: Condenser, 3: Jet device, 4: Suction port, 5: Nozzle, 6: Discharge port, 7:
Heat exchanger, 9: gas-liquid separator.

Claims (1)

[Scope of Claims] 1. In a refrigeration cycle in which a compressor, a condenser, and an evaporator are connected in sequence, an ejector having a condenser connected to the inflow side between the condenser and the evaporator, and a discharge of this ejector. a gas-liquid separator connected to the gas-liquid separator, a gas discharge passage for introducing the gas-phase refrigerant in the gas-liquid separator into the compressor inlet side, and a gas-liquid separator for introducing the liquid refrigerant in the gas-liquid separator into the evaporator. a discharge passage, a discharge passage for discharging a part of the liquid refrigerant in the gas-liquid separator, a pressure reduction mechanism connected to the discharge side of the discharge passage, and a gas-liquid separator connected to the discharge side of the pressure reduction mechanism. A gas-liquid separation supercooling system comprising a heat exchanger disposed within the separator to exchange heat with the liquid refrigerant inside the separator, and a return path for reintroducing the refrigerant discharged from the heat exchanger into the ejector. A circuit is provided, and this gas-liquid separation supercooling circuit reduces the pressure of the refrigerant discharged from the condenser and separates the refrigerant into gas and liquid, so that only the liquid refrigerant is introduced into the evaporator in a supercooled state. Refrigeration cycle.