KR20010108738A - The refrigerator being possessed of ejector as expansion apparatus - Google Patents

Abstract

A refrigerator provided with an ejector as an expander according to the present invention includes: an evaporator for absorbing heat from outside after the low pressure liquid refrigerant is introduced into the low pressure gas refrigerant; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser for cooling the high temperature and high pressure gas refrigerant compressed by the compressor to discharge the low temperature and high pressure liquid refrigerant; In the refrigerator consisting of an expander for expanding the low temperature and high pressure liquid refrigerant condensed in the condenser to make a low pressure liquid refrigerant to the evaporator,

The inflator is provided with an ejector for injecting a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid flowing out of the evaporator so as to be discharged at an appropriate pressure, and the evaporator is branched into two strands at the refrigerant outlet, respectively, and the compressor and the ejector are respectively. Characterized in that the conduit is configured so that the refrigerant flows into the furnace.

A refrigerator equipped with an ejector as the expander according to the present invention can circulate a refrigerant at the same mass flow rate, and can absorb more heat from inside and release it to the outside, while designing the same amount of heat absorption. In this case, the mass flow rate can be reduced to reduce the work of the compressor, and consequently, the performance coefficient of the refrigerator can be improved.

Description

The refrigerator being possessed of ejector as expansion apparatus}

The present invention relates to a refrigerator, and more particularly, to increase the coefficient of performance of a refrigerator by using an ejector instead of an expansion valve, which is used as an expander in a conventional refrigerator including a compressor, a condenser, an expander, and an evaporator according to a flow of a refrigerant. Relates to a refrigerator configured to be.

Meanwhile, the refrigerator operates by applying a phase change material called a refrigerant, and an evaporator, a compressor, a condenser, and an expander constituting the refrigerator are entirely connected, and the refrigerant is circulated without leakage in the connected system. As the refrigerant undergoes a phase change process, heat is absorbed at a certain place, and a process of releasing at another place is continuously performed to obtain a desired temperature at a specific place.

1 is a system configuration diagram of a conventional refrigerator.

Referring to FIG. 1, a conventional refrigerator includes an evaporator 10, a compressor 11, a condenser 12, and an expansion valve 13.

The evaporator 10 is installed in a place where a low temperature is to be maintained and is a device in which a low pressure liquid refrigerant absorbs external heat to become a low pressure gas refrigerant.

The compressor 11 is a device for compressing the evaporated low-pressure gas refrigerant to a high-temperature, high-pressure gas refrigerant, the device to induce the flow of the refrigerant in the refrigeration refrigeration system as a whole.

The condenser 12 is a device that cools the compressed high-temperature high-pressure gas refrigerant to a low-temperature high-pressure liquid refrigerant.

The inflator 13 is a device that expands the low-temperature, high-pressure liquid refrigerant by using a capillary tube to form a low-pressure liquid refrigerant.

Referring to the flow of heat absorbed or released in the above components, the heat absorbed by the evaporation of the refrigerant in the evaporator 10 is dissipated by the condensation of the refrigerant in the condenser 12 to eventually achieve the effect of cooling, This process will be explained on the diagram of PH, which is mainly used in thermodynamic refrigeration cycles, along with a description of the flow of refrigerant.

2 is a P-H diagram of a conventional refrigerator.

Referring to FIG. 2, the low-pressure gas refrigerant ST 1 discharged from the evaporator (see 10 of FIG. 1) becomes a high-temperature, high-pressure gas refrigerant ST 2 while passing through the compressor (see 11 of FIG. 1). The amount of work applied (W) is the product of the mass flow rate (m kg / s) and the change in enthalpy ((h _2- h ₁ ) kcal / kg), which is expressed by the following equation (1).

W (kcal / s) = m (kg / s) * (h ₂ -h ₁ ) (kcal / kg)

The high temperature and high pressure gas refrigerant (ST 2) passing through the compressor (see 11 of FIG. 1) discharges heat through the condenser (see 12 of FIG. 1), and the total heat quantity (Q _H ) discharged is the mass flow rate ( m kg / s) times the change in enthalpy ((h _3- h ₂ ) kcal / kg), which is expressed as Equation 2 below.

Q _H (kcal / s) = m (kg / s) * (h ₃ -h ₂ ) (kcal / kg)

The low temperature and high pressure liquid refrigerant (ST 3) passing through the condenser (see 12 of FIG. 1) is expanded through the expander (see 13 of FIG. 1), and serves to reduce the pressure while maintaining the same enthalpy in the expansion process. Therefore, the refrigerant ST 3 passing through the condenser (see 12 in FIG. 1) and the refrigerant ST 4 passing through the expander (see 13 in FIG. 1) are the same (h ₄ = h ₃ ) in enthalpy.

Finally, the heat is absorbed while passing through the evaporator (10 in FIG. 1), wherein the amount of heat absorbed (Q _L ) is the enthalpy (h ₄ ) of the refrigerant (ST 4) passing through the expander (see 13 in FIG. 1). ) And the enthalpy difference of the enthalpy (h ₁ ) of the refrigerant (ST 1) passing through the evaporator (see 10 in FIG. 1), which is expressed by Equation 3 below.

Q _L (kcal / s) = m (kg / s) * (h ₁ -h ₄ ) (kcal / kg)

When the efficiency of the refrigerator is obtained through Equations 1, 2, and 3, the efficiency of the refrigerator is utilized by a coefficient of performance (hereinafter referred to as COP), which is absorbed by the evaporator (see 10 in FIG. 1). The calorific value Q _L is defined as the value divided by the amount of work W consumed by the compressor (see 11 of FIG. 1), and is represented by Equation 4 below.

COP = Q _L / W

The higher the coefficient of performance (COP), the higher the performance of the refrigerator. In order to improve the coefficient of performance, the compressor (see 11 of FIG. 1) reduces the work (W) or the evaporator (see 10 of FIG. 1) absorption heat quantity. (Q _L ) must be increased. However, in the conventional refrigerator, the enthalpy (h ₃ ) before passing through the expansion valve (13 in FIG. 1) and the enthalpy (h ₄ ) after passing through the expansion valve (see 13 in FIG. 1) are capillaries. Therefore, the expansion loss is caused, there was a limit to increase the evaporator (see 10 in Figure 1) absorption heat (Q _L ). In other words, as shown in Equation 3, the enthalpy (h ₄ ) in ST 4 (see FIG. 2) cannot be reduced, thereby improving performance of the entire refrigerator.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a refrigerator capable of further improving the coefficient of performance (COP) by absorbing more heat under the same conditions.

1 is a system configuration diagram of a conventional refrigerator.

2 is a P-H diagram of a conventional refrigerator.

3 is a view schematically showing an ejector.

4 is a configuration diagram of a first embodiment of a refrigerator equipped with an ejector according to the present invention.

5 is a P-H diagram of a first embodiment of a refrigerator equipped with an ejector according to the present invention.

6 is a configuration diagram of another embodiment of a refrigerator having an ejector according to the present invention.

<Description of the symbols for the main parts of the drawings>

10, 35 ............ Evaporator 11, 31 ........ Compressor

12, 32 ............ Condenser 13 ............ Expansion valve

21..Moving fluid inlet port 22 ............ Suction fluid inlet port

27.Fluid outlet 23 ............ Nozzle section

24.Mixing section

25..Constant Area Section

26.Diffuser Section 33.Ejector

34..Gas Separator 41, 42, 43 ........ Valve

In order to achieve the above object, a refrigerator provided with an ejector as an expander according to the present invention comprises: an evaporator configured to absorb external heat and discharge the gas into a low pressure gas refrigerant after a low pressure liquid refrigerant is introduced; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser for cooling the high temperature and high pressure gas refrigerant compressed by the compressor to discharge the low temperature and high pressure liquid refrigerant; In the refrigerator consisting of an expander for expanding the low temperature and high pressure liquid refrigerant condensed in the condenser to make a low pressure liquid refrigerant to the evaporator,

The expander is composed of an ejector for driving the high-pressure driving fluid discharged from the condenser and the suction fluid of the low pressure discharged from the evaporator so as to be discharged at an appropriate pressure, the evaporator is divided into two strands at the refrigerant outlet, respectively, the compressor and the ejector Characterized in that the conduit is configured so that the refrigerant flows into.

3 is a view schematically showing the ejector.

Referring to Figure 3, when explaining the configuration of the ejector as a key element in the refrigerator provided with the ejector (Ejector) according to the present invention, the ejector has three holes, one in the front, side, the rear as a whole The hole in the drive fluid inlet 21, the hole in the side is the suction fluid inlet 22, the hole in the rear is the fluid outlet (27).

In addition, the configuration of the ejector together with the flow of the fluid, the configuration of the ejector can be divided into four zones, first, the nozzle section (Nozzle Section) 23 is the driving fluid inlet 21 and enlarged contraction The nozzle is sequentially accelerated to a supersonic state as the high-pressure driving fluid passes, and the pressure of the driving fluid is lower than that of the suction fluid due to the increased speed.

A mixing section 24 is provided after the nozzle section 23, and the mixing section 24 opens the suction fluid inlet 22 due to the pressure of the lowered driving fluid. The driving fluid and the suction fluid are mixed with each other by the suction fluid of the low pressure through each other, and maintain the supersonic speed as in the nozzle section 23.

A constant area section 25 is provided after the mixing section 24. The constant area section 25 is a straight tube with no change in cross-sectional area, in which it enters the supersonic state. Due to the difference between the pressure of the fluid and the pressure of the outlet, a vertical shock wave is generated.

After the constant area section 25, there is a diffuser section 26, which is a part of the fluid discharge, which is in the form of a tube, which reduces the velocity of the fluid as it passes through. And the pressure is raised.

With reference to the ejector described above will be described an embodiment in which a refrigerator equipped with an ejector as an inflator according to the present invention can exhibit the most desirable effect.

4 is a configuration diagram of a first embodiment of a refrigerator provided with an ejector as an expander according to the present invention.

Referring to FIG. 4, a refrigerator equipped with an ejector as an expander according to the present invention passes through a compressor (31) and a compressor (31) for making a low temperature low pressure gas refrigerant into a high temperature and high pressure gas refrigerant. Condenser (32) for cooling the gas of high temperature and high pressure to form a liquid refrigerant of low temperature and high pressure, using a low temperature and high pressure liquid refrigerant passed through the condenser (32) as a driving fluid, evaporator After the evaporation at (35), a low pressure gas refrigerant is used as the suction fluid, and the ejector 33 is replaced with an inflator which makes the proper pressure, and the proper pressure passed through the ejector 33 is measured. The liquid and gaseous mixed refrigerant is separated only from the refrigerant in the liquid state, and the liquid refrigerant is sent to the evaporator 35 and the gaseous refrigerant is sent to the compressor 31. (Separator) (34) An evaporator 35 for absorbing heat by evaporating the filtered liquid refrigerant, and valves 41 and 42 for adjusting the flow rate of individual pipes connecting the various components so that the refrigerator is normally operated. It consists of 43.

However, even if the gas-liquid separator 34, the valves 41, 42, 43 are deleted, only the surface of the refrigerator, such as the coefficient of performance of the refrigerator, is involved, and the operation of the refrigerator is not affected.

As an expander according to the present invention having the above configuration, a refrigerator provided with an ejector will be described based on the flow of refrigerant.

5 is a P-H diagram of a refrigerator provided with an ejector as an expander according to the present invention.

Referring to FIG. 5, a portion of the low-temperature low-pressure gas refrigerant ST 10 that passes through the gas-liquid separator (see 34 in FIG. 4) and the evaporator (see 35 in FIG. 4) in turn may be configured to use a compressor (see 31 in FIG. 4). While passing through the high-temperature, high-pressure gas refrigerant (ST 20), while passing through the compressor (see 31 of Figure 4) the high-temperature, high-pressure gas refrigerant (ST 20) is passed through the condenser (see 32 in Figure 4) The heat is lost to the low temperature and high pressure liquid refrigerant (ST 30), the refrigerant passing through the condenser (see 32 in Figure 4) to become a low temperature and high pressure liquid refrigerant (ST 30) enters the ejector 33, the role of the driving fluid Part of the low-pressure gas refrigerant (ST 10) passing through the evaporator (see 35 of FIG. 4) enters the ejector (see 33 of FIG. 4) and serves as an intake fluid, thereby ejecting the ejector (33 of FIG. 4). Eventually becomes a low-temperature, low-pressure gas-liquid mixed refrigerant (ST 40), and is released from the ejector (see 33 in FIG. 4). The gas-liquid mixed refrigerant (ST 40) is separated from the gas and liquid in the gas-liquid separator (see 34 of FIG. 4), respectively, and the gas refrigerant (ST 10) flows into the compressor (see 31 of FIG. 4) to complete the cycle. The liquid refrigerant ST 50 flows into the evaporator (see 35 in FIG. 4), and the evaporator (see 35 in FIG. 4) heats the liquid refrigerant ST 50 separated from the gas-liquid separator (see 34 in FIG. 4). The vaporized gas refrigerant ST 10 is absorbed and evaporated into the low pressure gas refrigerant ST 10. The vaporized gas refrigerant ST 10 is branched at the outlet of the evaporator 35, partly used as the suction fluid of the ejector 33, and partly introduced into the compressor 31. To complete the cycle.

With reference to the flow of the refrigerant as described above will be described in detail with reference to Figure 4 and Figure 5 the ejector portion of the refrigerator equipped with the ejector according to the present invention.

The ejector 33 is a low-temperature, high-pressure liquid refrigerant (ST 30) discharged from the condenser 32 is introduced into the drive fluid, the low-pressure gas refrigerant (ST 10) discharged from the evaporator 35 is introduced into the suction fluid In addition, the driving fluid and the suction fluid is mixed and discharged to the low-pressure gas-liquid mixed refrigerant (ST 40). The characteristic role of the ejector 33 is different from the capillary tube which has been mainly used as a conventional expander. It is not a process.

Since the process of the ejector 33 is not an equal enthalpy process, the enthalpy becomes smaller than the state after expansion (ST 60) when the conventional capillary tube is applied. This process is further strengthened through the gas-liquid separator (see 34 in FIG. 4) so that only the refrigerant enthalpy (ST 50) in the liquid state (50) is introduced into the evaporator 35.

On the other hand, by explaining the role of the valve 41, 42, 43 to control the flow rate of the individual pipes and the amount of flow rate controlled thereby, the conventional flower and the refrigerator provided with the ejector to the expander according to the present invention the same flow flow Refer to Table 1 below to give a reason to think.

sign Justice m ₁ Gas Flow Separator Outflow Refrigerant Flow m ₂ Flow rate of refrigerant entering the evaporator m ₃ Flow rate of incoming refrigerant from the evaporator to the compressor m _c Flow rate of incoming refrigerant to the compressor

Table 1 shows the flow rates of the individual pipes.

Referring to Tables 1, 4, and 5, the flow rate (m ₂ ) flowing into the evaporator 35 and the flow rate (m ₃ ) flowing into the compressor 31 from the evaporator 35 are defined in Table 1. As it is, the flow rate (m ₂ -m ₃ ) flowing out of the evaporator 35 to the ejector 33 is easily derived based on the symbols defined in Table 1 above. Based on the calculation formula for the flow rate of the pipeline, it can be adjusted as shown in Equation 5 to adjust the amount of flow rate flowing through the pipeline by adjusting the valve 41, 42, 43 to adjust the flow rate of the pipeline.

m ₁ = m ₂ -m ₃

That is, the flow rate m ₁ of the gas-liquid separator 34 and the outflow gas refrigerant may be the same as the flow rate flowing out of the evaporator 35 to the ejector 33.

When the equation (5) is modified, the equation (6) will be described.

m ₂ = m ₃ + m ₁

The inflow flow rate (m _c ) of the compressor is equal to the sum of the flow rate (m ₁ ) of the gaseous gas separator (35) outflow gas refrigerant and the flow rate (m ₃ ) flowing from the evaporator (35) to the compressor (31). When expressed as shown in Equation (7).

m _c = m ₃ + m ₁

Comparing Equation 6 and Equation 7 it can be seen that the inflow flow rate (m ₂ ) to the evaporator is the same as the inflow flow rate (m _c ) to the compressor.

That is, by adjusting the valves 41, 42, 43, the same amount of flow rate is controlled to flow through the evaporator 35 and the compressor 31 like the flow path of the single path of the conventional refrigerator.

Based on the control state for the flow of the flow rate described above in detail to the amount of heat absorption of the conventional refrigerator and the refrigerator provided with the ejector to the expander according to the present invention.

Referring to Equations 3 and 5, the heat absorption amount in the conventional refrigerator (Q _L (kcal / s) = m (kg / s) * (h _ST10- h _ST60 ) (kcal / kg) and the present invention When comparing the heat absorption amount (Q _L (kcal / s) = m (kg / s) * (h _ST10- h _ST50 ) (kcal / kg)) of the refrigerator equipped with the ejector with the corresponding expander, the flow rate is equally controlled Since it is a state, referring to the change in enthalpy, it can be seen that the amount of heat absorption of the refrigerator provided with the ejector is increased according to the present invention.

In addition, calculating the increase (Q _I ) of the heat absorption amount of the refrigerator equipped with the ejector according to the present invention is given by the following equation (8).

Q _I (kcal / s) = m (kg / s) * (h _ST60 -h _ST50 ) (kcal / kg)

However, in order for the above interpretation to be applied correctly, the amount of refrigerant flowing into the evaporator should be the same in the refrigerator provided in the ejector according to the conventional refrigerator and the expander according to the present invention. Such a control method is described through Equations 5 to 8 above. There is a bar.

In addition, by varying the control method of the valve 41, 42, 43, it is possible to obtain even higher efficiency.

As described above, unlike the related art, since the refrigerator provided with the ejector according to the present invention has an increased heat absorption amount Q _L at a low temperature, the coefficient of performance mentioned in Equation 4 is increased.

Comparing the above-described coefficient of performance (COP) in a refrigerator equipped with an ejector according to the present invention and the conventional refrigerator is represented by the equations (9) and (10).

COP = Q _L / W is the conventional refrigerator,

COP = m * (h _ST10 -h _ST60 ) / W

COP = Q _L / W is a refrigerator provided with an ejector to the expander according to the present invention,

COP = m * (h _ST10 -h _ST50 ) / W

Comparing Equations 9 and 10, since one (W) of the compressor has the same flow rate, the coefficient of performance (COP) is greater than the coefficient of performance (COP) of the conventional refrigerator in the refrigerator provided with the ejector according to the present invention. Able to know.

As another embodiment of the refrigerator provided with the ejector according to the present invention will be described a refrigerator using an expander to which the ejector and the expansion belt are applied at the same time.

6 is a configuration diagram of a second embodiment of a refrigerator provided with an ejector according to the present invention.

Referring to Fig. 6, the first and second embodiments of the refrigerator having an ejector according to the present invention are similar in overall configuration, but the ejector 33 and the gas-liquid separator 34 are characteristic parts of the second embodiment. The expansion valve 36 is inserted between the two, but when the expansion valve 36 is inserted incompletely expanded in the ejector 33, the expansion can be more surely. .

As the expansion valve 36 is added as described above, the decompression becomes accurate, thereby enabling the state of the desired refrigerant to be more accurately realized.

As described above, the refrigerator provided with the ejector as the expander according to the present invention can circulate the refrigerant at the same mass flow rate, while absorbing more heat and dissipating more heat to the outside while maintaining the same work of the compressor. In the case of design, the mass flow rate can be reduced to reduce the work of the compressor, and consequently, there is an advantage of improving the performance coefficient of the refrigerator.

Claims (5)

An evaporator for absorbing external heat and discharging the low pressure liquid refrigerant to a low pressure gas refrigerant; A compressor for compressing the low pressure gas refrigerant evaporated in the evaporator and discharging the gas refrigerant to high temperature and high pressure gas refrigerant; A condenser for cooling the high temperature and high pressure gas refrigerant compressed by the compressor to discharge the low temperature and high pressure liquid refrigerant; In the refrigerator consisting of an expander for expanding the low temperature and high pressure liquid refrigerant condensed in the condenser to make a low pressure liquid refrigerant to the evaporator, The inflator is composed of an inflator for injecting a high-pressure driving fluid discharged from the condenser and a low-pressure suction fluid flowing out of the evaporator to be discharged at an appropriate pressure, respectively, and the evaporator is branched into two strands at the refrigerant outlet, respectively. Refrigerator provided with an ejector to the inflator, characterized in that the conduit is configured so that the refrigerant flows into the furnace. The method of claim 1, And at least one side of the pipe branch branched from the outlet of the evaporator is provided with an ejector as an inflator. The method of claim 1, And a gas-liquid separator is installed between the ejector and the evaporator so that the liquid refrigerant flows into the evaporator and the gas refrigerant flows into the compressor. The method of claim 3, wherein The outlet of the gas-liquid separator, a pipe that flows out from the evaporator to the compressor, a pipe for adjusting the flow rate in the pipe flows out from the evaporator to the ejector is provided with an ejector provided with an expander. The method according to claim 1 or 4, And an expansion valve is inserted at an outlet of the ejector to more precisely control the depressurization of the refrigerant.