JP2009127920A - Refrigerating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating apparatus capable of remarkably increasing refrigerating capability using an expansion mechanism of a simple structure. <P>SOLUTION: In this refrigerating apparatus, a condenser 2 including a compressor 1 and a blower 2a and an evaporator 3 including an expansion mechanism 10 and a blower 3a are connected in series by refrigerant pipelines 4, 5, 6, 7 to constitute a closed-loop refrigerant circulating circuit. The expansion mechanism 10 is constituted of a cylindrical housing 11 and a vortex tube 13 concentrically disposed in the housing 11, a refrigerant is jetted from a nozzle formed in the vortex tube 13 in the tangential direction in the vortex tube 13 to generate a vortex flow in the vortex tube 13, and the vortex flow is released from the end of the vortex tube 13 to expand the refrigerant. A pre-expansion valve 8 is disposed in the refrigerant pipeline 5 connecting the condenser 2 and the expansion mechanism 10. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vapor compression refrigeration apparatus using an expansion mechanism using eddy currents.

  The refrigeration apparatus liquefies the high-pressure refrigerant compressed by the compressor by heat exchange in the condenser to form a high-temperature condensed refrigerant, expands the condensed refrigerant by expansion means, generates a low-temperature refrigerant, and converts the low-temperature refrigerant into the evaporator The required cooling is performed by the latent heat of vaporization at that time. As the expansion means of this refrigeration apparatus, those using a throttle mechanism have been mainstream, and those using a narrow tube such as a capillary tube and those using an ejector that is expanded by a high-speed jet jet are known. .

In Patent Documents 1 and 2, a vortex tube is provided as an expansion means on the downstream side of the condenser in the refrigerant circulation circuit, and the evaporation capacity is improved by bringing the expansion of the condensed refrigerant close to isentropic expansion in the vortex tube. A freezing device has been proposed.
JP-A-8-303879 JP-A-8-313072

  The refrigeration apparatuses proposed in Patent Documents 1 and 2 both use a vortex tube vortex as a means for heat separation, but have a problem that it is difficult to use in a general-purpose refrigeration cycle. The vortex tube thermally separates the refrigerant into a high temperature and a low temperature by a vortex, and has a disadvantage that the flow rate of the low-temperature refrigerant decreases because the primary refrigerant is divided into two to generate the low-temperature refrigerant. And since the structure which returns the high temperature refrigerant | coolant which came out of the vortex tube to the upstream of a condenser is employ | adopted, there exists a contradiction that a refrigerant | coolant is returned to the higher one from a low pressure.

  Therefore, the present applicant has previously proposed an expansion mechanism as shown in FIG. 8 (in Japanese Patent Application Nos. 2006-136502 and 2007-154684). Here, the expansion mechanism shown in FIG. 8 will be described.

  FIG. 8 is a cross-sectional view of the expansion mechanism previously proposed by the present applicant. The illustrated expansion mechanism 110 is configured by concentrically incorporating a vortex tube 113 in a cylindrical outer cylinder 111, and this vortex The upper outer periphery of the tube 113 is supported on the inner peripheral surface of the outer cylinder 111 by a ring-shaped support plate 112. The inside of the outer cylinder 111 is partitioned into a chamber S1, an expansion chamber S2, and a liquid reservoir S3 from above by the support plate 112 and a ring-shaped baffle plate 114 disposed below the support plate 112. Here, the lower end of the vortex tube 113 opens into the expansion chamber S2, and a zone separator 115 is provided at the opening. The zone separator 115 separates the vacuum region R1 formed at the center of the vortex tube 113 from the gas-liquid separation region R2 below the opening end of the vortex tube 113 in the expansion chamber S2, and has an upper end. The portion faces the lower end in the vortex tube 113, and a minute cylindrical gap is formed between them.

  By the way, a plurality of slits (not shown) are radially formed in the baffle plate 114, and a plurality of baffle plates 116 are radially arranged in the upper part of the liquid reservoir S3 below the baffle plate 114. It is installed.

  The vortex tube 113 has an upper end opening covered with a cover 117, and a plurality of nozzles 118 (only one is shown in FIG. 8) opening in the chamber S1 are provided in a tangential direction on the outer periphery of the upper end. It has been. A suction pipe 119 is inserted into the upper central portion of the vortex tube 113 from above through the upper wall of the outer cylinder 111 and the cover 117, and the lower end of the suction pipe 119 is inserted into the vortex tube 113. It is open.

  Further, a port 120 that opens to the chamber S1 and a port 121 that opens to the expansion chamber S2 are provided on the outer peripheral portion of the outer cylinder 111, and a port 122 that opens to the liquid reservoir S3 is provided at the center of the lower end of the outer cylinder 111. A rectifier 123 is provided on the outer periphery of the vortex tube 113 between the port 121 and the gas-liquid separation zone R2 in the vertical direction in the expansion chamber S2.

  Thus, although not shown, the refrigeration apparatus is configured by connecting a compressor, a condenser, the above expansion mechanism, and an evaporator with a refrigerant pipe to form a closed-loop refrigerant circulation circuit. The refrigerant piping led out from the side is connected to the inlet side of the condenser, and the refrigerant piping led out from the outlet side of the condenser is connected to the port 120 of the expansion mechanism 110. The refrigerant piping led out from the port 122 of the expansion mechanism 110 is connected to the inlet side of the evaporator, and the refrigerant piping led out from the outlet side of the evaporator is connected to the suction pipe 119 of the expansion mechanism 110. The refrigerant pipe leading out from the port 121 of the expansion mechanism 110 is connected to the suction side of the compressor.

  However, the expansion mechanism 110 shown in FIG. 8 has a drawback that the structure is complicated.

  The present invention has been made in view of the above problems, and an object thereof is to provide a refrigeration apparatus capable of significantly increasing the refrigeration capacity using an expansion mechanism having a simple structure.

  In order to solve the above-mentioned object, the invention according to claim 1 is a refrigeration in which a compressor, a condenser including a blower, an expansion mechanism, and an evaporator including a blower are connected in series by a refrigerant pipe to form a closed-loop refrigerant circulation circuit. In the apparatus, the expansion mechanism includes a cylindrical housing and a vortex tube arranged concentrically in the housing, and refrigerant is jetted into the vortex tube in a tangential direction from a nozzle formed in the vortex tube. Thus, a vortex is generated in the vortex tube, and the refrigerant is expanded by releasing the vortex from the end of the vortex tube.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, a pre-expansion valve is arranged in a refrigerant pipe connecting the condenser and the expansion mechanism.

  The invention according to claim 3 is the invention according to claim 2, wherein the pre-expansion valve is an electronic expansion valve.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein a baffle is provided between an end of the vortex tube in the housing of the expansion mechanism and a refrigerant outlet. To do.

  The invention according to claim 5 is the invention according to claim 4, characterized in that the baffle is constituted by a baffle stay or a net-like member arranged radially.

  According to the first aspect of the present invention, the refrigerant can be isentropically expanded by the expansion mechanism, the pressure loss of the refrigerant in the expansion mechanism can be kept small, and the flow rate of the refrigerant supplied to the evaporator can be reduced as much as possible. Since the refrigerant enthalpy difference can be further increased and the refrigerant temperature can be lowered, a refrigerating apparatus having a large refrigerating capacity and high efficiency can be obtained.

  In addition, since the expansion mechanism has no moving parts and has a simple structure, the durability of the expansion mechanism can be improved and the expansion mechanism can be applied to various refrigerants. Even with this expansion mechanism, since the conventional refrigeration cycle can be used almost as it is, it is possible to easily improve the refrigeration apparatus currently in operation to a highly efficient one having a large refrigeration capacity.

  According to the second aspect of the invention, since the high-pressure liquid refrigerant is adiabatically expanded by the pre-expansion valve before the refrigerant is introduced into the expansion mechanism, the refrigerant does not completely evaporate in the evaporator 3 and remains liquid refrigerant. It is possible to prevent the occurrence of the problem of being sucked by the compressor and cope with load fluctuations.

  According to the third aspect of the present invention, since the pre-expansion valve is an electronic expansion valve that can be artificially controlled by program control, occurrence of hunting can be prevented.

  According to the fourth and fifth aspects of the present invention, since the baffle is provided in the liquid reservoir at the bottom of the housing, the swirling movement of the refrigerant is prevented by the baffle, and the liquid refrigerant accumulated in the liquid reservoir is normally discharged from the refrigerant outlet. And is stably supplied to the evaporator, and is used for evaporation in the evaporator to perform required cooling.

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

  FIG. 1 is a refrigerant circuit diagram showing a basic configuration of a refrigeration apparatus according to the present invention, and FIG. 2 is a cross-sectional view of an expansion mechanism of the refrigeration apparatus.

  As shown in FIG. 1, the refrigeration apparatus according to the present embodiment includes a compressor 1, a condenser 2 including a blower 2a, an evaporator 3 including a blower 3a, and an expansion mechanism 10 according to the present invention. , 6 and 7 to form a closed loop refrigerant circulation circuit. A pre-expansion valve 8 is provided in the middle of the refrigerant pipe 5.

  Next, details of the configuration of the expansion mechanism 10 will be described with reference to FIG.

  The expansion mechanism 10 includes a cylindrical container-shaped housing 11, and the inside of the housing 11 is partitioned into upper and lower chambers S 1 and an expansion chamber S 2 by a partition wall 12. A cylindrical vortex tube 13 extending downward from the center of the upper wall of the housing 11 is accommodated concentrically in the housing 11, and the vortex tube 13 penetrates the partition wall 12. Extends to the expansion chamber S2, and its lower end opens into the expansion chamber S2.

  Further, two nozzles 14 communicating with the chamber S1 and the inside of the vortex tube 13 are formed in a tangential direction with respect to the inner peripheral surface of the vortex tube 13 at the upper end of the vortex tube 13 facing the chamber S1. .

  Further, a port 15 that opens to the chamber S1 is provided on the outer periphery of the upper end of the housing 11, and the refrigerant pipe 5 extending from the condenser 2 is connected to the port 15 (see FIG. 1). Further, a port 16 that opens to the expansion chamber S <b> 2 is provided in the center of the bottom wall of the housing 11, and the refrigerant pipe 6 connected to the evaporator 3 is connected to the port 16.

  Next, the operation of the refrigeration apparatus provided with the expansion mechanism 10 having the above configuration will be described below with reference to the Mollier diagram shown in FIG.

When the compressor 1 is driven by an electric motor (not shown) which is a drive source, the gas refrigerant is compressed by the compressor 1 (compression stroke), and the state (pressure P ₂ , enthalpy i ₂ ) shown in FIG. ) Is discharged to the refrigerant pipe 4, and this gas refrigerant is introduced into the condenser 2 through the refrigerant pipe 4.

In the condenser 2, the high-temperature and high-pressure gas refrigerant releases the condensation heat Q ₂ to the outside air, changes its state from a to b in FIG. 3 and liquefies (condensation process), and the state (pressure) shown in FIG. P ₂ and enthalpy i ₃ ) liquid refrigerant. Note that the heat release amount (condensation heat) Q _{2 at} this time is represented by (i ₂ −i ₃ ).

Then, the high-pressure liquid refrigerant liquefied in the condenser 2 as described above undergoes adiabatic expansion (equal enthalpy expansion) in the pre-expansion valve 8 in the process of flowing through the refrigerant pipe 5, and b → e (pressure P shown in FIG. 3). ₂ ′, enthalpy i ₃ ) (pre-expansion stroke), the air is introduced into the chamber S 1 in the housing 11 from the port 15 of the expansion mechanism 10. In the pre-expansion valve 8, a part of the refrigerant condensed in the condenser 2 undergoes adiabatic expansion, the temperature thereof drops to some extent, and the gas is mixed into a gas-liquid mixture and the volume is increased and sent to the expansion mechanism 10. It is done.

  In the expansion mechanism 10, the high-pressure liquid refrigerant introduced into the chamber S <b> 1 is ejected tangentially from the two nozzles 14 into the vortex tube 13 to form a vortex that rotates at high speed on the inner wall surface of the vortex tube 13. The wall surface static pressure in the vortex tube 13 increases. Accordingly, a low pressure portion is generated by the vortex in the center portion of the vortex tube 13, and the gas refrigerant freely flows into the vortex tube 13 from the expansion chamber S2 due to this low pressure portion. As a result, the pressure on the wall surface in the vortex tube 13 further increases.

Thus, the wall static pressure that has risen due to the vortex flow in the vortex tube 13 is released at a stretch at the open end of the vortex tube 13 and falls, so that the refrigerant drops in temperature and blows out into the expansion chamber S2. That is, the pressure energy of the refrigerant is converted into kinetic energy by the nozzle 14, the vortex flow in the vortex tube 13 formed by the kinetic energy is converted into wall surface static pressure, and the wall surface static pressure is released at a stroke, whereby the refrigerant is The isentropic expansion (expansion stroke) changes to e → c (pressure P ₁ , enthalpy i ₄ ) shown in FIG. When a throttle such as an expansion valve is used as the expansion mechanism, the refrigerant performs adiabatic expansion (isoenthalpy expansion) whose state changes from b → c ′ (pressure P ₁ , enthalpy i ₃ ) in FIG.

Thus, the refrigerant expanded in the expansion chamber S <b> 2 of the expansion mechanism 10 is introduced from the port 16 opened at the lower end of the housing 11 into the evaporator 3 through the refrigerant pipe 6. Then, in the evaporator 3, the low-temperature and low-pressure liquid refrigerant takes the heat of evaporation Q1 from the surroundings and changes its state from c → d in FIG. 3 to evaporate (evaporation process), and the state d (pressure P ₁ , endalpy i ₁ ) Gas refrigerant. The evaporator 3 cooled by evaporation of liquid refrigerant in is performed, the heat absorption amount at the time of evaporation (latent heat of evaporation) Q ₁ is represented by (i ₁ -i _4), use the aperture such expansion valve as an expansion mechanism In this case, as described above, the refrigerant performs adiabatic expansion (isoenthalpy expansion) whose state changes from b → c ′ (pressure P ₁ , enthalpy i ₃ ) in FIG. In contrast, in the present embodiment, as described above, the refrigerant is isentropically expanded in the expansion mechanism 10 and changes its state from e → c (pressure P ₁ , enthalpy i ₄ ) in FIG. The endothermic amount Q2 increases by Δi (= i ₃ −i ₄ ), and the refrigeration capacity of the refrigeration apparatus is increased accordingly.

The gas refrigerant evaporated in the evaporator 3 is sucked into the compressor 1 through the refrigerant pipe 7, the compressor 1, gas refrigerant in the state shown in FIG. 3 d (pressure P _1, enthalpy i ₁₎ Is compressed by the compressor 1 and changes in state from d → a (pressure P ₂ , enthalpy i ₂ ) in FIG. 3 (compression stroke), and thereafter the same operation as described above is repeated. Here, the required power (motor output) L of the compressor 1 is represented by (i ₂ −i ₁ ) in FIG.

  Thus, in the refrigeration apparatus according to the present invention, the refrigeration cycle described above is repeated, and the required refrigeration is performed by the heat absorption accompanying the evaporation of the refrigerant in the evaporator 3, but according to the present embodiment, The following effects can be obtained.

  That is, in the present embodiment, since the expansion mechanism 10 that expands the refrigerant in an isentropic manner is used, the pressure loss of the refrigerant in the expansion mechanism 10 is suppressed to be small, and the flow rate of the refrigerant supplied to the evaporator 3 is reduced as much as possible. In addition, the enthalpy difference of the refrigerant can be further increased, the refrigerant temperature can be lowered, and a refrigerating apparatus having a large refrigerating capacity and high efficiency can be obtained.

  In addition, since the expansion mechanism 10 has no moving parts, the durability of the expansion mechanism 10 can be improved, and the expansion mechanism 10 can be applied to a wide variety of refrigerants. Since the conventional refrigeration cycle can be used almost as it is, it is possible to easily improve the currently operating refrigeration apparatus to a highly efficient one having a large refrigeration capacity.

In addition, although the pre-expansion valve 8 is provided in the present embodiment, the opening degree of the pre-expansion valve 8 is controlled based on the temperature and pressure of the refrigerant flowing through the refrigerant pipe 7 on the secondary side of the evaporator 3. By doing so, it is possible to prevent the problem that the refrigerant does not completely evaporate in the evaporator 3 and is sucked into the compressor as the liquid refrigerant, and to cope with load fluctuations. Both the mechanical type and the electronic type can be used for the pre-expansion valve 8, but the occurrence of hunting can be prevented by using an electronic type that can be artificially controlled by program control. Benefits are gained.
Next, another embodiment of the expansion mechanism will be described with reference to FIGS.

  4 is a cross-sectional view of an expansion mechanism according to another embodiment, FIG. 5 is a cross-sectional view showing the flow of refrigerant in the expansion mechanism, FIG. 6 is a cross-sectional view taken along line AA in FIG. 5, and FIG. It is sectional drawing of such an expansion mechanism, In these figures, the same code | symbol is attached | subjected to the same element as what was shown in FIG. 2, and the reexplanation about them below is abbreviate | omitted.

  The expansion mechanism 10 ′ shown in FIGS. 4 to 6 is characterized in that a baffle 18 is provided in a liquid reservoir at the bottom in the housing 11, and as shown in FIG. Then, eight baffle stays 19 are arranged radially at an equiangular pitch.

  Thus, in the expansion mechanism 10 ′ according to the present embodiment, the jet of refrigerant injected from the nozzle 14 into the vortex tube 13 forms a vortex 31 in the vortex tube 13 as shown in FIG. Since the vortex 31 is pressed against the inner wall of the vortex tube 13 by centrifugal force, the wall surface static pressure of the vortex tube 13 increases. When the refrigerant blows out from the vortex tube 13 into the expansion chamber S2, when the refrigerant is released from the inner wall as the regulating wall of the vortex tube 13, the wall surface static pressure disappears, and at the same time, the refrigerant temperature also drops rapidly. The refrigerant blows out into the expansion chamber S2 in a gas-liquid mixed state.

  As described above, the refrigerant that has been released from the restriction by the inner wall of the vortex tube 13 and has fallen in temperature falls as a swirling flow 32 along the inner wall of the expansion chamber S2 while decelerating. Then, the lowered refrigerant flows into the liquid reservoir 17 through the gap between the inner wall of the expansion chamber S2 and the baffle 18, and further flows into the port 16 of the expansion mechanism 10, but in the liquid reservoir 17, the swirling flow 32 of the refrigerant. Is stopped by the baffle stay 19 because its turning motion is hindered.

  Incidentally, in the case where the swirling movement of the refrigerant in the liquid reservoir 17 is not blocked, the liquid refrigerant forms a swirling flow, that is, a vortex, and the port 16 disposed in the central portion becomes a low pressure at the center of the vortex. A phenomenon in which the refrigerant hardly flows out from the port 16 occurs.

  Thus, in the expansion mechanism 10 according to the present embodiment, the baffle 18 is provided in the liquid reservoir 17 at the bottom in the housing 11, and the swirling movement of the refrigerant is prevented by the baffle 18. The liquid refrigerant normally flows out from the port 16 and is supplied to the evaporator 3 (see FIG. 1) through the refrigerant pipe 6 and is subjected to evaporation in the evaporator 3 to perform required cooling.

  Of the refrigerant that has flowed into the expansion chamber S2, the gas refrigerant rises toward the low pressure portion formed in the central portion of the vortex tube 13 to cause an upward flow 33, which further increases the pressure in the low pressure portion and the vortex flow 31. Since it strongly presses against the inner wall of the vortex tube 13, it acts to further increase the wall surface static pressure of the vortex tube 13.

  In addition, the expansion mechanism 10 ″ shown in FIG. 7 is characterized in that a mesh member is installed as a baffle 18 ′ at the bottom of the housing 11, and the baffle 18 ′ made of this mesh member also allows the refrigerant in the expansion chamber S2 to flow. The revolving motion can be prevented, and the same effect as described above can be obtained.As the mesh member, any member having a baffle function can be used. Thus, it is possible to use a collection of thin metals, a continuous foam made of a material that is stable against the refrigerant, and the like.

It is a refrigerant circuit diagram which shows the basic composition of the freezing apparatus which concerns on this invention. It is sectional drawing of the expansion mechanism of the freezing apparatus which concerns on this invention. It is a Mollier diagram which shows the state change of the refrigerant | coolant in the freezing apparatus which concerns on this invention. It is sectional drawing of the expansion mechanism which concerns on another form. It is sectional drawing which shows the state of the flow of the refrigerant | coolant in the expansion mechanism which concerns on another form. It is the sectional view on the AA line of FIG. It is sectional drawing of the expansion mechanism which concerns on another form. It is sectional drawing of the conventional expansion mechanism.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 2a Condenser blower 3 Evaporator 3a Evaporator blower 4-7 Refrigerant piping 8 Pre expansion valve 10 Expansion mechanism 10 ', 10 "Expansion mechanism 11 Housing 12 Partition wall 13 Vortex tube 14 Nozzle 15, 16 port 17 liquid reservoir 18, 18 'baffle 19 baffle stay 31 vortex flow 32 swirl flow 33 upward flow S1 chamber S2 expansion chamber

Claims (5)

In a refrigeration apparatus that forms a closed-loop refrigerant circulation circuit by connecting a compressor, a condenser including a blower, an expansion mechanism, and an evaporator including a blower in series with a refrigerant pipe,
The expansion mechanism is composed of a cylindrical housing and a vortex tube concentrically arranged in the housing, and a refrigerant is jetted in a tangential direction from the nozzle formed in the vortex tube into the vortex tube. A refrigeration apparatus characterized in that a vortex is generated in a pipe and the vortex is released from an end of the vortex pipe to expand the refrigerant.   The refrigerating apparatus according to claim 1, wherein a pre-expansion valve is disposed in a refrigerant pipe connecting the condenser and the expansion mechanism.   The refrigerating apparatus according to claim 2, wherein the pre-expansion valve is an electronic expansion valve.   The refrigeration apparatus according to any one of claims 1 to 3, wherein a baffle is provided between an end of the vortex tube in the housing of the expansion mechanism and a refrigerant outlet.   5. The refrigeration apparatus according to claim 4, wherein the baffle is configured by a baffle stay or a net-like member arranged radially.

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