JP2006090599A - Refrigerating apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating apparatus of excellent refrigerating efficiency using an air cycle that can acquire high refrigerating efficiency. <P>SOLUTION: The refrigerating apparatus 1 is composed of an adsorber 2a for dehumidifying moisture discharged from a refrigerating chamber 3; a compressor 2c for compressing dehumidified air supplied from the adsorber 2a through a dehumidified air supply line 2b; a waste heat recovering heat exchanger 2e for recovering the heat of compressed air discharged from the compressor 2c through a compressed air discharge line 2d; an expansion turbine 2g for adiabatically expanding heat-recovered air supplied from the waste heat recovering heat exchanger 2e through a heat-recovered air supply line 2f; and a refrigerating air supply line 2h for supplying the refrigerating chamber 3 with adiabatically expanded refrigerating air discharged from the expansion turbine 2g. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a refrigeration apparatus using an air cycle, and more particularly to a refrigeration apparatus using an air cycle that is excellent in refrigeration efficiency and can achieve high refrigeration efficiency.

There is a refrigeration apparatus that freezes an object to be frozen using an air cycle without using a refrigerant such as Freon.
As such a refrigeration apparatus, for example, one having a configuration described later is known. According to the refrigeration apparatus according to Conventional Example 1, as described above, since the object to be frozen can be frozen without using a synthetic refrigerant such as chlorofluorocarbon, interest in the global environment has increased in recent years. Attracted attention.

  That is, this is an air cycle cooling device, and this air cycle cooling device includes a circuit that performs an air cycle by sequentially connecting an expander, a heat exchanger, and a compressor. In this circuit, the first air is taken in as the working fluid of the air cycle. The taken-in 1st air is pressure-reduced below atmospheric pressure with an expander, and becomes low temperature. The first air having a low temperature exchanges heat with the second air in the heat exchanger. The second air is cooled by this heat exchange, and the cooled second air is supplied into the room for cooling. The first air that has absorbed heat from the second air by the heat exchanger is compressed to the atmospheric pressure by the compressor and discharged from the circuit. In this air conditioner, the expander is constituted by a turbine device, and the compressor is constituted by a turbo compressor. The impellers of the expander and the compressor are connected to each other by a turbine shaft. The turbine shaft is driven by a motor. Moreover, the expansion work when air expand | swells is comprised so that it may collect | recover as drive force of a compressor via a turbine shaft (for example, refer patent document 1).

  In the case of the air cycle cooling device according to Conventional Example 1, the air taken in is directly expanded by an expander. Since the taken-in air contains moisture, there is a problem that a part of the expansion work is taken away by the moisture as heat of condensation, and the expansion work cannot be recovered sufficiently. And since collection | recovery of expansion work becomes inadequate, the motive power for driving a compressor increases, and there existed a problem of causing a fall of COP (coefficient of performance) resulting from this.

  By the way, an air conditioner has been proposed in which the power required for air compression is reduced to improve COP. Hereinafter, an outline of the air conditioner according to the second conventional example will be described with reference to FIG. 4 of a schematic configuration diagram showing the configuration thereof. The code | symbol 40 shown in FIG. 4 is an air conditioning apparatus. The air conditioner 40 includes an air cycle unit 41, a dehumidifying mechanism 90 that is a dehumidifying means, and an internal heat exchanger 45. The air cycle unit 41 includes a cycle circuit 50. The cycle circuit 50 is configured such that an expander 52, a heat exchanger 60, and a compressor 51 are duct-connected in order, and endothermic air flows to perform an air cycle operation.

  The cycle circuit 50 includes an inlet duct 53 connected to the inlet side of the expander 52 and an outlet duct 54 connected to the outlet side of the compressor 51. One end of the inlet duct 53 opens to the outside, takes in outdoor air as heat absorption air, and supplies the taken heat absorption air to the expander 52. One end of the outlet duct 54 opens to the outside and discharges the heat absorption air from the compressor 51 to the outside. The compressor 51 and the expander 52 are connected by a rotating shaft 66 driven by a motor 65, and are configured to be driven by the motor 65. A heat absorption side passage 62 is defined in the heat exchanger 60. One end of the heat absorption side passage 62 is duct-connected to the expander 52 and the other end is connected to the compressor 51, and the heat absorption air flows inside. The heat exchanger 60 is configured to exchange heat between the heat absorption air in the heat absorption side passage 62 and the indoor air that is the air to be cooled.

The dehumidifying mechanism 90 is provided in the middle of the inlet duct 53 and the outlet duct 54.
The dehumidifying mechanism 90 includes a rotor member 91, a moisture absorbing unit 92, and a moisture releasing unit 93, and has the same configuration as a rotary type dehumidifier. The rotor member 91 has a disk shape and is configured to allow air to pass in the thickness direction. The rotor member 91 includes a solid adsorbent that adsorbs moisture, and constitutes a humidity medium that causes the air passing therethrough to contact the solid adsorbent.
Further, although not shown, the rotor member 91 is connected to a drive motor, and is configured to move between the moisture absorbing portion 92 and the moisture releasing portion 93 by being rotationally driven by the drive motor.
The solid adsorbent of the rotor member 91 is composed mainly of a porous inorganic compound.

As the inorganic compound, one that has a pore diameter of about 0.1 to 20 nm and adsorbs moisture is selected.
Since the hygroscopic portion 92 is disposed in the middle of the inlet duct 53, in the hygroscopic portion 92, the endothermic air in the inlet duct 53 passes through the rotor member 91, and the moisture in the endothermic air is solid adsorbed by the rotor member 91. Adsorbed to the agent. Thereby, the endothermic air is dehumidified. Since the moisture releasing portion 93 is disposed in the middle of the outlet duct 54, the heat absorbing air in the outlet duct 54 passes through the rotor member 91 and is adsorbed on the solid adsorbent of the rotor member 91 in the moisture releasing portion 93. The dehydrated moisture is desorbed and released into the endothermic air. Thereby, the solid adsorbent is regenerated.

According to the air conditioner 40 configured as described above, moisture in the endothermic air is removed in advance by the solid adsorbent of the rotor member 91. Therefore, since part of the expansion work is not lost to moisture as condensation heat, the expansion work can be sufficiently recovered. Since the expansion work is sufficiently collected, the power for driving the compressor does not increase, so there is no fear that the COP will decrease (see, for example, Patent Document 2).
Japanese Patent Application Laid-Open No. 5-238489 JP 2000-314569 A

  According to the air conditioner according to the above-described conventional example 2, as described above, a part of the expansion work is not lost to moisture as condensation heat, and the expansion work can be sufficiently recovered, which is excellent. . However, the refrigeration part in the air cycle is below the atmosphere, and process air cannot be directly blown into the freezer compartment. Accordingly, since a heat exchanger is required between the object to be frozen and the refrigeration unit, the refrigeration efficiency is lowered. Further, since the process air is cycled at a low pressure, a high refrigeration efficiency cannot be obtained.

  Accordingly, an object of the present invention is to provide a refrigeration apparatus that is excellent in refrigeration efficiency and that can obtain a high refrigeration efficiency.

  The present invention has been made in view of the above circumstances, and therefore, the means employed by the refrigeration apparatus according to claim 1 of the present invention in order to solve the above problems is a refrigeration apparatus for cooling an object to be cooled in a freezer compartment. A dehumidifying means for dehumidifying moisture in the air discharged from the freezer compartment, a compressor for compressing dehumidified air supplied from the dehumidifying means via a dehumidified air supply line, and a compressor for compressing the dehumidified air. Waste heat recovery heat exchanger that recovers the heat of the compressed air discharged through the air discharge line, and post-heat recovery air supplied from the waste heat recovery heat exchanger via the post-heat recovery air supply line And a refrigerating air supply line for supplying the refrigerating air after adiabatic expansion discharged from the expander to the freezing chamber.

  The means employed by the refrigeration apparatus according to claim 2 of the present invention is the refrigeration apparatus according to claim 1, wherein the waste heat recovery heat exchanger exchanges heat with the heat of the compressed air to obtain a high temperature. A dehumidifying agent regeneration air supply line for supplying air to the dehumidifying means is provided.

  The means employed by the refrigeration apparatus according to claim 3 of the present invention is the refrigeration apparatus according to any one of claims 1 and 2, wherein the dehumidified air flowing through the dehumidified air supply line and the heat recovery are provided. A heat recovery heat exchanger is provided in which heat is exchanged with the air after heat recovery flowing through the rear air supply line, and the air after this heat recovery is cooled.

The refrigeration apparatus according to claims 1 to 3 of the present invention compresses the dehumidified air discharged from the freezer compartment and dehumidified by the dehumidifying means with a compressor, and the heat of the compressed air is used as waste heat recovery heat. In this configuration, the air after heat recovery recovered by the exchanger is adiabatically expanded by an expander to obtain low-temperature freezing air.
Therefore, since the pressure of the professional air does not fall below the atmospheric pressure and the freezing air that has become low temperature due to adiabatic expansion can be directly supplied to the freezing room, the object to be frozen in the freezing room can be frozen. Efficiency is improved. In addition, because the pressure of the process air is high until it flows out from the air outlet of the freezer compartment and flows into the freezer inlet of the freezer compartment through the dehumidifying means, compressor, waste heat recovery heat exchanger, and expander High refrigerating capacity.

  The refrigeration apparatus according to claim 2 of the present invention includes a dehumidifying agent regeneration air supply line for supplying the dehumidifying means with the air heat-exchanged with the compressed air in the waste heat recovery heat exchanger. Therefore, waste heat can be effectively used for regeneration of the dehumidifying agent, and the temperature of the compressed air supplied to the expander can be lowered, so that the temperature of the refrigeration air after adiabatic expansion is lowered. Can do.

  The refrigeration apparatus according to claim 3 of the present invention includes dehumidified air discharged from the freezer compartment, dehumidified by the dehumidifying means and flowing through the dehumidified air supply line, and post-heat recovery air flowing through the post-heat recovery air supply line, The heat recovery heat exchanger is further provided for further cooling the air after the heat recovery. Accordingly, it is possible to supply lower-temperature compressed air to the expander, and to lower the temperature of the refrigerating air after adiabatic expansion. Can do.

  Hereinafter, the refrigeration apparatus according to Embodiment 1 of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram showing a configuration of a refrigeration apparatus according to Embodiment 1 of the present invention.

  Reference numeral 1 shown in FIG. 1 is a refrigeration apparatus using an air cycle according to Embodiment 1 of the present invention, and this refrigeration apparatus 1 includes an air cycle circuit 2 having a configuration to be described later. The air cycle circuit 2 includes an adsorber 2 a that is a dehumidifying means for dehumidifying moisture in the air discharged from the air outlet 3 a of the freezer compartment 3. The compressor 2c compresses the dehumidified air supplied from the adsorber 2a via the dehumidified air supply line 2b, and heat of the compressed air discharged from the compressor 2c via the compressed air discharge line 2d. The waste heat recovery heat exchanger 2e is recovered.

  Further, the heat exchanger 2e for waste heat recovery is provided with an expansion turbine 2g that is an expander for adiabatically expanding the air after heat recovery supplied via the air supply line 2f after heat recovery, and discharged from the expansion turbine 2g. The refrigerating air supply line 2h for supplying the refrigerating air after adiabatic expansion to the refrigerating air inlet 3b of the freezing chamber 3 is provided. The compressor 2c and the expansion turbine 2g are configured to be rotated by a rotating shaft 6 that is rotated by a drive motor 5 in the same manner as in the second conventional example.

Further, the refrigeration apparatus 1 dehumidifier regeneration that supplies dehumidifier regeneration air (hereinafter referred to as adsorbent regeneration air) that removes moisture adsorbed by an adsorbent (dehumidifier) (not shown) of the adsorber 2a. An adsorbent regeneration line 4 that is an air supply line is provided. The adsorbent regeneration line 4 communicates with the adsorber 2a via the waste heat recovery heat exchanger 2e, and the compressed air recovered by the waste heat recovery heat exchanger 2e Heat is exchanged with heat to generate high-temperature adsorbent regeneration air, and this adsorbent regeneration air is supplied to the adsorber 2a, and the adsorbent regeneration air containing moisture after regeneration of the adsorbent is discharged from the adsorber 2a to the atmosphere. It is configured to release inside.
The adsorber 2a is the same as the conventional one, and has a rotary configuration, and the adsorbent is a solid adsorbent mainly composed of a porous inorganic compound.

  Hereinafter, the operation mode of the refrigeration apparatus 1 according to the first embodiment of the present invention will be described. The air discharged from the air outlet 3a of the freezer compartment 3 is dehumidified by the adsorber 2a, and the dehumidified air is supplied to the compressor 2c via the dehumidified air supply line 2b. The supplied dehumidified air is compressed to a pressure about three times the atmospheric pressure by the compressor 2c, and the compressed air is supplied to the waste heat exchange heat exchanger 2e via the compressed air discharge line 2d. In this heat exchanger 2e for waste heat exchange, the compressed air raises the temperature of the air flowing through the adsorbent regeneration line 4 to a high temperature, and the compressed air becomes a low temperature. Flow into. And it is adiabatically expanded by this expansion turbine 2g, becomes freezing air having a temperature corresponding to the dehumidification rate, and flows into the freezing air inlet 3b of the freezing room 3 through the freezing air supply line 2h.

  In Embodiment 1 of the present invention, the air after heat recovery supplied to the expansion turbine 2g is dehumidified in advance, so that moisture does not condense and solidify during adiabatic expansion, and the air generated by dehumidification By lowering the saturation temperature, it is possible to supply cooler freezing air to the freezer compartment 3. The pressure of the refrigeration air after adiabatic expansion at the outlet of the expansion turbine 2g is the same as the atmospheric pressure. Therefore, since the refrigeration air having the same pressure as the atmospheric pressure can be directly blown and supplied to the object to be cooled, the heat exchange between the refrigeration apparatus and the object to be frozen can be performed rather than the indirect refrigeration method via the conventional heat exchanger. Efficiency is improved. In addition, waste heat can be effectively utilized for regeneration of the adsorbent, which is extremely economical.

  Next, a refrigeration apparatus according to Embodiment 2 of the present invention will be described with reference to the accompanying drawings. FIG. 2 is a schematic configuration diagram showing the configuration of the refrigeration apparatus according to Embodiment 2 of the present invention, and FIG. 3 is an explanatory diagram of the relationship between the refrigeration air temperature and the dehumidification rate (%) of the dehumidified air. The second embodiment is different from the first embodiment in that a heat recovery heat exchanger is provided in the air cycle circuit, and all other configurations are the same as those in the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and the differences will be mainly described with the same names.

  As well understood in the comparison between FIG. 1 and FIG. 2, the dehumidified air discharged from the air outlet 3a of the freezer compartment 3 and dehumidified by the adsorber 2a and flowing through the dehumidified air supply line 2b, and the heat There is provided a heat recovery heat exchanger 2i for exchanging heat with the air after heat recovery flowing through the post-recovery air supply line 2f and further cooling the air after heat recovery.

  Accordingly, the compressed air at a lower temperature can be supplied to the expansion turbine 2g, and the temperature of the refrigerating air after the adiabatic expansion can be lowered, so that the low-temperature refrigerating air is supplied from the freezer compartment. be able to.

  More specifically, as described in FIG. 2, the air discharged from the air outlet 3a of the freezing chamber 3 (0.1 MPa, −30 ° C., 1.74E−0.5 kg / kg) is adsorbed. The dehumidified air (-29.98 ° C, 1.0E-0.5kg / kg) flows into the heat recovery heat exchanger 2i through the dehumidified air supply line 2b and is dehumidified at 40 ° C. The air is supplied to the compressor 2c. The supplied dehumidified air at 40 ° C. is compressed by this compressor 2c to a pressure approximately three times the atmospheric pressure, and the compressed air (0.3 MPa, 132.4 ° C.) is compressed via the compressed air discharge line 2d. It is supplied to the heat exchanger 2e for waste heat exchange. In addition, kg / kg in 1.74E-0.5 kg / kg and 1.0E-0.5 kg / kg means the weight of water per 1 kg of air.

  In the heat exchanger 2e for waste heat exchange, the compressed air raises the temperature of the air flowing through the adsorbent regeneration line 4 to a high temperature of 39.7 ° C., and the post-heat recovery air supply line 2f is used as the post-heat recovery air. It flows into the heat recovery heat exchanger 2i through the heat exchange, becomes -30.3 ° C. by heat exchange, and flows into the expansion turbine 2g. And it is adiabatically expanded by this expansion turbine 2g, becomes freezing air (0.1 MPa, −70.9 ° C.) having a temperature corresponding to the dehumidification rate, and freezes the freezing room 3 through the freezing air supply line 2h. Flows into the air inlet 3b. The freezing air at the freezing air inlet 3b of the freezing chamber 3 is 0.1 MPa, −60 ° C., 1.0E−0.5 kg / kg.

The relationship of the refrigeration air temperature to the dehumidification rate (%) of the dehumidified air supplied to the compressor is indicated by taking the refrigeration air temperature (° C) on the vertical axis and the dehumidification rate (%) on the horizontal axis. The relationship is as shown in FIG. That is, according to FIG. 3, it is shown that the lower the temperature of the dehumidifying air supplied to the compressor, the lower the temperature of the freezing air that can be supplied to the freezing chamber 3.
More specifically, in Embodiment 2 of the present invention, when the dehumidification rate of the dehumidified air is 0%, the freezing air at about −57 ° C. is used, and when the dehumidification rate of the dehumidified air is 25%, about −65. When the dehumidification rate of the dehumidified air is 42%, the freezing air at about −70.9 ° C. can be supplied to the freezing chamber 3. The reason why the lower temperature freezing air can be supplied to the freezer compartment 3 is that the saturation temperature of the air decreases due to dehumidification.

  In the above, the case where the adsorbent of the adsorber 2a is a solid adsorbent mainly composed of a porous inorganic compound has been described as an example. However, for example, an absorbent such as lithium bromide, lithium hydrate, sodium hydroxide, or the like Alternatively, a separation membrane such as a gas separation membrane can be used.

It is a schematic block diagram which shows the structure of the freezing apparatus which concerns on form 1 of this invention. It is a schematic block diagram which shows the structure of the freezing apparatus which concerns on Embodiment 2 of this invention. FIG. 10 is an explanatory diagram of the relationship of the refrigeration air temperature to the dehumidification rate (%) of the dehumidified air according to the second embodiment of the present invention. It is a schematic block diagram which shows the structure of the air conditioning apparatus which concerns on the prior art example 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Refrigeration apparatus 2 ... Air cycle circuit, 2a ... Adsorber, 2b ... Dehumidified air supply line, 2c ... Compressor, 2d ... Compressed air supply line, 2e ... Heat exchanger for waste heat exchange, 2f ... Air after heat recovery Supply line, 2g ... expansion turbine, 2h ... refrigeration air supply line, 2i ... heat recovery heat exchanger 3 ... freezing room, 3a ... air outlet, 3b ... refrigeration air inlet 4 ... adsorbent regeneration line 5 ... electric Motor 6 ... Rotating shaft

Claims (3)

  A refrigeration apparatus for cooling an object to be cooled in a freezer compartment, comprising dehumidifying means for dehumidifying moisture in air discharged from the freezer compartment, and dehumidified air supplied from the dehumidifying means via a dehumidified air supply line Compressor to compress, waste heat recovery heat exchanger that recovers heat of compressed air discharged from this compressor through compressed air discharge line, and air supply after heat recovery from this waste heat recovery heat exchanger An expander that adiabatically expands the air after heat recovery supplied through the line, and a refrigerating air supply line that supplies the refrigerating air after adiabatic expansion discharged from the expander to the freezer compartment. A refrigeration apparatus characterized by that.   A dehumidifying agent regeneration air supply line for supplying high-temperature air, which has been heated to a high temperature by heat exchange with the heat of the compressed air in the waste heat recovery heat exchanger, is provided. Item 2. The refrigeration apparatus according to item 1. A heat recovery heat exchanger is provided that heat-exchanges dehumidified air flowing through the dehumidified air supply line and post-heat recovery air flowing through the post-heat recovery air supply line, and cools the air after heat recovery. The refrigeration apparatus according to any one of claims 1 and 2.

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