JP6218659B2 - Refrigeration air conditioner - Google Patents

Description

  The present invention relates to a refrigeration air conditioner.

  In a refrigeration air conditioner having a refrigeration cycle in which a compressor, a condenser, an expansion valve, and an evaporator are connected in an annular shape, outside air is blown to the evaporator by a fan to exchange heat with the refrigerant inside the evaporator, and then used for air conditioning. Supply. Further, in the evaporator, when the outside air passes, moisture contained in the outside air is condensed, and water droplets (drain water) are generated on the surface of the evaporator.

  Thus, the condensed water generated in the evaporator is drained as it is (for example, refer to Patent Document 1) or reused (for example, refer to Patent Document 2). In Patent Document 2 in which condensed water is reused, condensed water is dropped directly onto the condenser, and the refrigerant in the condenser is cooled by heat exchange by the latent heat of vaporization of the condensed water. Thus, the heat exchange efficiency of the condenser is improved by exchanging the refrigerant in the condenser with the condensed water in addition to the heat exchange with the condenser cooling air.

Japanese Patent Laying-Open No. 2008-39208 (page 7, FIG. 1) JP 2010-175171 A (7th page, FIG. 2)

  During operation at high loads during summertime when the outdoor air temperature is high, the refrigerating capacity required to lower the air supplied from the refrigerating and air-conditioning apparatus to the air conditioning application to the target temperature increases. In order to make up for this necessary capacity, it is necessary to increase the compressor capacity in the refrigeration cycle, resulting in excessive overall unit power. Then, although the method of reusing the condensed water which generate | occur | produced with the evaporator can be considered, patent document 1 does not show about reuse of condensed water in the first place. Moreover, in patent document 2, although shown about reuse of condensed water, the method of reducing the required cooling capacity of a refrigerating cycle is not shown.

  This invention is made | formed in view of such a point, and it aims at obtaining the refrigerating air-conditioning apparatus which can reduce the required cooling capacity of a refrigerating cycle by reuse of condensed water.

The refrigerating and air-conditioning apparatus according to the present invention includes a compressor, a condenser, a decompression device, and an evaporator. And a heat exchange device that is configured by a tank in which condensed water generated by the evaporator is stored, and that exchanges heat with each other through independent channels that do not mix with the air blown by the blower. Is.

  According to the present invention, the required cooling capacity can be reduced by reusing condensed water.

It is a figure which shows the refrigerant circuit of the refrigerating air conditioning apparatus which concerns on Embodiment 1 of this invention. It is action | operation explanatory drawing of the heat exchanger for condensed water of the refrigerating air conditioning apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the principal part containing the condensed water tank of the refrigeration air conditioning apparatus which concerns on Embodiment 2 of this invention. It is a figure which shows the structure of the principal part containing the heat exchanger for condensed water of the refrigeration air conditioning apparatus which concerns on Embodiment 3 of this invention. It is effect | action explanatory drawing of the refrigerating air conditioning apparatus which concerns on Embodiment 3 of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the embodiments described below. Moreover, what attached | subjected the same code | symbol in each figure is the same or it corresponds, and this is common in the whole text of a specification. Furthermore, the forms of the constituent elements appearing in the entire specification are merely examples and are not limited to these descriptions. Further, the level of temperature, pressure, etc. is not particularly determined in relation to absolute values, but is relatively determined in terms of the state, operation, etc. of the system, apparatus, etc.

Embodiment 1 FIG.
1 is a diagram showing a refrigerant circuit of a refrigeration air-conditioning apparatus according to Embodiment 1 of the present invention.
The refrigeration air conditioner includes a compressor 1, a condenser 2, an expansion valve 3 that is a decompression device, and an evaporator 4, and includes a refrigeration cycle that is connected by refrigerant piping. The refrigerating and air-conditioning apparatus further includes a fan 5 that is a blower that blows air to the evaporator 4 and a heat exchanger 6 for condensed water.

  In the present invention, the condensed water generated in the evaporator 4 is reused so that the amount of moisture in the air flowing into the evaporator 4 is not changed on the upstream side of the evaporator 4, and the condensed water and the evaporator 4 are changed. Heat is exchanged with the air flowing into the air, and a heat exchanger 6 for condensed water is arranged on the upstream side of the evaporator 4 as a heat exchange device. In addition, as a method of reusing condensed water for heat exchange with air, for example, there is a method of supplying heat to the porous plate and exchanging heat by passing air through the porous plate. However, in this method, moisture of condensed water is added to the air. In the present invention, such a method is not adopted, and a heat exchange is performed between the condensed water and the air flowing into the evaporator 4 by a method that does not change the amount of moisture in the air flowing into the evaporator 4 as will be described later. Let

  The heat exchanger 6 for condensed water is comprised by the fin tube type heat exchanger which has a heat exchanger tube and a fin, and is comprised so that condensed water may pass the inside of a heat exchanger tube. In other words, the condensed water heat exchanger 6 exchanges heat with each other through independent channels in which the condensed water generated in the evaporator 4 and the air blown by the fan 5 are not mixed with each other. It has become. With this configuration, as described above, heat exchange with condensed water is performed by a method in which the amount of moisture in the air flowing into the evaporator 4 does not change.

  Moreover, the evaporator 4 is also comprised with a fin tube type heat exchanger. The condenser 2 may be any heat exchanger that exchanges heat between the refrigerant and the heat medium supplied as an external heat source and dissipates heat to the heat medium, and may be a finned tube heat exchanger or a plate-type heat exchanger. It is good also as an exchanger.

The operation of the refrigeration air conditioner configured as described above will be described.
In the refrigeration cycle, the refrigerant discharged from the compressor 1 flows into the condenser 2, exchanges heat with a heat medium such as air passing through the condenser 2, and flows out as a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that has flowed out of the condenser 2 is decompressed by the expansion valve 3 to become a low-pressure two-phase refrigerant, and flows into the evaporator 4. The low-pressure two-phase refrigerant that has flowed into the evaporator 4 exchanges heat with the air passing through the evaporator 4 by the fan 5 to become a low-pressure gas refrigerant, and is sucked into the compressor 1 again.

  On the other hand, the air passing through the evaporator 4 by the fan 5 is cooled by exchanging heat with the refrigerant in the evaporator 4 and supplied to the air conditioning application as supply air. Here, moisture in the air passing through the evaporator 4 is condensed on the surface of the fins of the evaporator 4. This condensed water is guided to a heat exchanger 6 for condensed water provided on the air upstream side of the evaporator 4.

  The air flowing into the condensed water heat exchanger 6 by the fan 5 is cooled by exchanging heat with condensed water in the condensed water heat exchanger 6. As described above, the condensed water heat exchanger 6 is composed of a finned tube heat exchanger, and the air supplied from the fan 5 to the condensed water heat exchanger 6 is condensed water without adding condensed water. It is cooled by exchanging heat with it and supplied to the evaporator 4. The air flowing into the evaporator 4 is further cooled by exchanging heat with the refrigerant in the evaporator 4 and supplied to the air conditioning application. The condensed water after heat exchange with the air from the fan 5 in the condensed water heat exchanger 6 is discharged to the outside.

  FIG. 2 is an operation explanatory diagram of the heat exchanger for condensed water of the refrigeration air-conditioning apparatus according to Embodiment 1 of the present invention, and shows an air diagram. The horizontal axis is the dry bulb temperature [° C.], and the vertical axis is the absolute humidity [kg / kg (DA)]. In FIG. 2, the temperature of the air discharged from the fan 5 to the heat exchanger 6 for condensed water is 42 ° C. and the supply temperature of the supply air supplied to the air-conditioning application during high load operation where the outdoor air temperature is high in summer. The example in case (target temperature) is 13 degreeC is shown. Further, in FIG. 2, the curve passing through the points B and C is an air diagram of the first embodiment provided with the heat exchanger 6 for condensed water, and the curves passing through the points A, B and C are for condensed water. The air diagram of the comparative example which is not provided with the heat exchanger 6 is shown. In addition, the specific numerical value of each temperature shown here is only an example, and changes according to actual use conditions.

  About 42 ° C. fan air (point A) discharged from the fan 5 to the condensed water heat exchanger 6 is heated by the condensed water in the condensed water heat exchanger 6 and the absolute humidity remains unchanged. Cool to 40 ° C. (point B). The air cooled in the condensed water heat exchanger 6 is then supplied to the evaporator 4, and heat exchange with the refrigerant in the evaporator 4 causes the temperature to drop to the supply temperature, and moisture in the air condenses. This reduces the absolute humidity (point C).

  Here, when this Embodiment 1 is compared with a comparative example, the state of the air flowing into the evaporator 4 is changed from the dry bulb temperature of 42 ° C. without changing the absolute humidity due to the heat exchange effect by the reuse of the condensed water. It can be lowered to about 40 ° C. Therefore, in reducing the air flowing into the evaporator 4 to the supply temperature, the specific enthalpy difference (Δ specific enthalpy) between the inlet side and the outlet side of the evaporator 4 required in the first embodiment becomes Δh1, It is possible to lower the specific enthalpy difference Δh2 of the example.

  The cooling capacity is obtained by multiplying the air volume and the Δ ratio enthalpy. Here, assuming that the air flow is the same, the condensed water is reused in the heat exchanger 6 for condensed water, so that the Δ ratio enthalpy is reduced as described above. be able to. The dehumidification amount is obtained by multiplying the air volume and the absolute humidity difference (Δ absolute humidity).

  As described above, according to the first embodiment, the required cooling capacity in the evaporator 4 can be suppressed by reusing condensed water, so that the capacity of the compressor 1 in the refrigeration cycle can be reduced. Thus, the power of the entire unit can be reduced. For example, in a general refrigeration air conditioner of 60 horsepower, it is necessary in the first embodiment when cooling the fan air (point A) of about 42 ° C. sent from the fan 5 to the supply temperature (target temperature) 13 ° C. The specific enthalpy difference (Δ specific enthalpy) between the inlet side and the outlet side of the evaporator 4 becomes Δh1 = 50 kg / kJ, and the specific enthalpy difference Δh2 = 53 kg / kJ of the comparative example is about 6%. Capability can be reduced. Therefore, it is possible to configure a refrigerating and air-conditioning apparatus that can cope with a high load when the outdoor air temperature is high in summer while suppressing the overall power of the unit.

  In addition, since the installation position of the heat exchanger 6 for condensed water should just be an upstream from the evaporator 4, the upstream of the fan 5 and a downstream are not ask | required.

Embodiment 2. FIG.
In the first embodiment, the heat exchanger 6 for condensed water is used as the heat exchange device, but in the second embodiment, a condensed water tank is used.

  FIG. 3 is a diagram illustrating a configuration of a main part including a condensed water tank of the refrigeration air-conditioning apparatus according to Embodiment 2 of the present invention. Other configurations of the refrigeration air conditioner are the same as those in FIG. In the following, the second embodiment will be described focusing on the differences from the first embodiment.

  The condensed water tank 7 is arranged on the air upstream side of the evaporator 4 in the same manner as the condensed water heat exchanger 6. Then, the condensed water generated in the evaporator 4 is accumulated, and the compressed air sent out from the fan 5 is exchanged with the condensed water before flowing into the evaporator 4. The condensed water tank 7 is configured to have a size that does not block the flow path from the fan 5 to the evaporator 4, and performs heat exchange between the air from the fan 5 and the condensed water in the condensed water tank 7. The condensed water tank 7 is also configured to exchange heat with air without adding condensed water, like the condensed water heat exchanger 6.

  In the heat exchanger 6 for condensed water, the condensed water after heat exchange with the air from the fan 5 is discharged outside. The effect of providing the condensed water tank 7 is the same as that of the first embodiment. The installation position of the condensed water tank 7 may be on the upstream side of the evaporator 4 as in the first embodiment, so that the upstream side and the downstream side of the fan 5 are not limited.

  As described above, according to the second embodiment, the same effects as those of the first embodiment can be obtained.

Embodiment 3 FIG.
In the first and second embodiments, the evaporator 4 is a single-stage cooling, but the third embodiment is a multi-stage cooling including a plurality of evaporators 4.

  FIG. 4 is a diagram showing a configuration of a main part including a heat exchanger for condensed water of the refrigeration air conditioner according to Embodiment 3 of the present invention. Other configurations of the refrigeration air conditioner are the same as those in FIG. In the following, the third embodiment will be described focusing on the differences from the first embodiment.

  In the first and second embodiments, there is one refrigeration cycle, but the refrigeration air-conditioning apparatus of the third embodiment includes a plurality of independent refrigeration cycles. Here, two refrigeration cycles, a refrigeration cycle having a compressor 1A, a condenser 2A, an expansion valve 3A and an evaporator 4A, and a refrigeration cycle having a compressor 1B, a condenser 2B, an expansion valve 3B and an evaporator 4B are performed. I have. And the evaporator group 40 is comprised by evaporator 4A, 4B of each refrigeration cycle. Here, the air upstream side is the evaporator 4A, and the air downstream side is the evaporator 4B.

  And the refrigerating air-conditioning apparatus of Embodiment 3 is provided with the heat exchanger 6 for condensed water in the air upstream of the evaporator group 40 similarly to Embodiment 1. FIG. Here, an example in which the condensed water heat exchanger 6 is arranged upstream of the fan 5 is shown, but the condensed water heat exchanger 6 may be upstream of the evaporator group 40 and upstream of the fan 5. The side and the downstream side are not important. Moreover, it is good also as the condensed water tank 7 of Embodiment 2 instead of the heat exchanger 6 for condensed water.

  FIG. 5 is an operation explanatory diagram of the refrigeration air-conditioning apparatus according to Embodiment 3 of the present invention, and shows an air diagram. The horizontal axis is the dry bulb temperature [° C.], and the vertical axis is the absolute humidity [kg / kg (DA)]. FIG. 5 shows that the temperature of the air flowing into the condensed water heat exchanger 6 by the fan 5 is 42 ° C. during the high load operation when the outdoor air temperature is high in summer, and the supply temperature of the supply air supplied to the air conditioning application ( An example in which the target temperature is 0 ° C. is shown. Further, in FIG. 5, the curve passing through the points B and C is an air diagram of the third embodiment provided with the heat exchanger 6 for condensed water, and the curves passing through the points A, B and C are for condensed water. The air diagram of the comparative example which is not provided with the heat exchanger 6 is shown. In addition, the specific numerical value of each temperature shown here is only an example, and changes according to actual use conditions.

  As the fan 5 rotates, the fan air (point A) at about 42 ° C. flows into the heat exchanger 6 for condensed water, and is cooled to about 40 ° C. without changing the absolute humidity by heat exchange with the condensed water ( Point B). The air cooled by the heat exchanger 6 for condensed water is then supplied to the evaporator 4A, where heat is exchanged with the refrigerant of the evaporator 4A, the temperature is lowered to about 12 ° C., and moisture in the air is condensed. By doing so, the absolute humidity decreases (point D). The air after passing through the evaporator 4A is supplied to the evaporator 4B, exchanges heat with the refrigerant of the evaporator 4B, the temperature decreases to about 0 ° C., and the moisture in the air condenses to further reduce the absolute humidity. Lower (point E).

  Here, the case where the heat exchanger 6 for condensed water is provided and the case where the heat exchanger 6 is not provided are considered to have the same cooling capacity in the evaporator 4A on the upstream side of the air, that is, two evaporators 4A and 4B. In the configuration of FIG. 4 provided with the heat exchanger 6 for condensed water, the specific enthalpy difference Δh11 of the evaporator 4A is cooled to the point C without providing the heat exchanger 6 for condensed water, and the air is cooled by one evaporator. In the case where the specific enthalpy difference Δh21 is the same as that in the case, the cooling capacity originally necessary for the evaporator 4 as a whole can be spared by heat exchange with the condensed water on the upstream side of the evaporator 4A. That is, by using this surplus cooling capacity (= air volume × Δh3), the air supplied to the evaporator 4B is further cooled by the evaporator 4A on the upstream side of the air and then supplied to the evaporator 4B. The cooling capacity and the dehumidification amount in the evaporator 4B can be suppressed as compared with the case where the heat exchanger 6 for condensed water is not provided.

  In the example of FIG. 5, the specific enthalpy difference (Δ specific enthalpy) between the inlet side and the outlet side of the evaporator 4 </ b> B is such that the condensed water heat exchanger 6 is not provided by using the condensed water heat exchanger 6. The specific enthalpy difference Δh22 is reduced to the specific enthalpy difference Δh12, and the cooling capacity can be suppressed by “air volume × Δh3”. Further, the dehumidifying amount can be suppressed by “air volume × ΔSH”. That is, in reducing the fan air to the supply temperature, the specific enthalpy difference required for the entire evaporator group 40 is reduced by Δh3 by providing the heat exchanger 6 for condensed water, so this specific enthalpy difference Δh3 min. The specific enthalpy required for the evaporator 4B on the downstream side of the air in the evaporator group 40 can be lowered, and the cooling capacity in the evaporator 4B can be suppressed.

  As described above, according to the third embodiment, in addition to obtaining the same unit power reduction effect as in the first embodiment, the dehumidification amount in the evaporator 4B on the downstream side in the air flow direction can be reduced. Moreover, it becomes possible to suppress the amount of frost formation as the whole evaporator group 40. FIG. For example, in a general refrigerating and air-conditioning apparatus having 120 horsepower, when the fan air (point A) of about 42 ° C. sent from the fan 5 is cooled to the supply temperature (target temperature) 0 ° C., the air in Embodiment 3 is used. Assuming that the cooling capacity in the upstream refrigeration cycle (evaporator 4A) is the same, the dehumidification amount generated in the evaporator 4B = 54 L / h, the dehumidification amount in the comparative example = 61 L / h, and the downstream evaporator The amount of dehumidification generated in 4B can be reduced by about 11%. Thereby, the amount of frost formation of the evaporator 4B can be reduced.

  Here, the case of two-stage cooling has been described as an example, but the same effect can be obtained even with a multi-stage cooling method having more than two stages.

  1, 1A, 1B compressor, 2, 2A, 2B condenser, 3, 3A, 3B expansion valve, 4, 4A, 4B evaporator, 5 fan, 6 heat exchanger for condensed water, 7 condensed water tank, 40 evaporation Instrument group.

Claims (3)

A refrigeration cycle having a compressor, a condenser, a decompression device and an evaporator, in which the refrigerant circulates;
A blower for blowing air to the evaporator;
It is arranged on the air upstream side of the evaporator and is composed of a tank in which condensed water generated in the evaporator is stored, and passes through independent flow paths that do not mix with the air blown by the blower. A refrigeration air conditioner comprising a heat exchange device for heat exchange. A plurality of refrigeration cycles having a compressor, a condenser, a pressure reducing device, and an evaporator, in which refrigerant circulates;
A blower for blowing air to an evaporator group composed of a plurality of the evaporators of the plurality of refrigeration cycles;
It is arranged on the air upstream side of the evaporator group, and is composed of a tank in which condensed water generated in the evaporator group is stored, and passes through an independent flow path that does not mix with the air blown by the blower. A refrigerating and air-conditioning apparatus, comprising: The refrigerating and air-conditioning apparatus according to claim 2, wherein the cooling capacity of the evaporator on the downstream side of the plurality of evaporators is reduced by the cooling capacity obtained by the heat exchange device.

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