KR101152435B1 - Hot Air Heat Pump System of Air Cycle - Google Patents

Abstract

The present invention relates to a hot air pump pump system of an air cycle, in the cooling mode, the air circulating through the air cycle is passed through the expander to obtain a cooling effect, and in the heating mode through the expansion valve to obtain a heating effect, It is an object of the present invention to provide an air cycle hot air pump system capable of simultaneously cooling and heating the system.

In order to achieve the above object, the present invention, in the air cycle including a compressor (11), a high temperature heat exchanger (12), an expander (13) and a regenerator (17), the compressor (11) and the On the circulation path of the air between the high temperature heat exchanger 12, a branch point 19 is provided, in which a part of the air branches in the circulation and is directly supplied to the air conditioning space 15, and the branch point 19 and the air conditioning space are provided. On the circulation path of the air between the (15) and the expansion valve (18) is provided for expanding the air in isoenthalpy, characterized in that for controlling the amount of air branching at the branch point (19) by the branch amount adjusting means. It is done.

Air cycle, hot air pump system, expansion valve, divergence control

Description

Hot Air Heat Pump System of Air Cycle

1 is a conceptual diagram of a conventional refrigeration cycle,

2 is a schematic configuration diagram of an air cycle as a closed system,

3 is a TS diagram of the air cycle of FIG.

4 is a schematic configuration diagram of an air cycle as an open system,

5 is a schematic configuration diagram of an air cycle as an open system equipped with a regenerator;

Figure 6 is a schematic diagram showing an embodiment of a hot air pump system according to the present invention,

Figure 7 is a schematic diagram showing another embodiment of a hot air pump system according to the present invention,

8 is a TS diagram in the hot air pump system according to the present invention.

* Description of the symbols for the main parts of the drawings *

11 ... compressor 12 ... high temperature heat exchanger

13 ... Inflator 15 ... HVAC

17 Regenerator 18 Expansion valve

19 ... Junction 20 ... First valve

21 ... 2nd valve 22 ... 3 way valve

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot air heat pump system of an air cycle, and more particularly, in a cooling mode, air is circulated through an air cycle to an expander to obtain a cooling effect. In the heating mode, an expansion valve is passed to obtain a heating effect, and the present invention relates to an air cycle hot air pump system capable of simultaneously cooling and heating in one system.

Generally, a refrigerating machine used for refrigerating or freezing foods includes a refrigeration cycle in which a refrigerant is phase-changed into a gas phase and a liquid phase, and air cooling of the air blown into the air-conditioning space is carried out by absorption and release of latent heat. Apply.

1, a conceptual diagram of a conventional refrigeration cycle is shown.

In a conventional refrigeration cycle, R-134a is used as a refrigerant, and as shown in FIG. 1, the refrigerant is compressed at a high temperature and a high pressure in the compressor 1, and then condensed in a liquid state in the condenser 2. The condensed refrigerant is passed through the expansion valve (3) to expand easily to vaporize, and then the expanded refrigerant is evaporated in the evaporator (4), through the refrigerant passing through the evaporator (4) and the evaporator (4) The freezing effect is obtained by heat exchange with air supplied to the air conditioning space.

R-134a, which is a refrigerant used in the conventional refrigeration cycle as described above, is known to be the main culprit of environmental degradation such as global warming, and therefore, its use is expected to be suppressed and gradually banned.

Therefore, interest in the development of alternative refrigerants to replace the R-134a is increasing, and accordingly CO ₂ and R-152a have been discussed as the next-generation alternative refrigerants.

However, since CO ₂ requires a high operating pressure, all parts applied to the refrigeration cycle must be newly developed for high pressure, and thus the cost of the parts can be changed by changing the thickness of the material and changing the specifications to improve the pressure resistance. There is a problem that this rises.

On the other hand, the R-152a has the advantage that the parts used in the existing refrigeration cycle using the R-134a can be used as it is, but R-152a itself is ASHRAE (American Society of Heating, Refrigerating and Air-conditioning Engineers) Since it belongs to the A2 group (refrigerant group having a slightly flammable) among the prescribed refrigerant groups, there is a problem that it is somewhat unstable to use as a general refrigerant.

Therefore, by using a new cycle that replaces the conventional refrigeration cycle rather than replacing the refrigerant itself as described above, efforts to develop a new system that is environmentally friendly, safe and efficient.

The most promising one of these alternative cycles is the air cycle using the reverse-Brighton cycle.

An air cycle is a system that uses a gaseous fluid, in particular air, as a refrigerant, and is a cycle in which a refrigeration effect is obtained by operating a Brayton cycle, which is a kind of gas power cycle, in reverse.

The biggest advantage of the air cycle is that there is no problem of environmental destruction such as ozone layer destruction and global warming, which were problems of the existing refrigerants because air is used as the refrigerant.

2 shows a schematic configuration diagram of the air cycle, and FIG. 3 shows a TS diagram of the air cycle.

2 and 3, the basic principle of the air cycle is as follows.

The overall circulation of the air cycle includes: (i) a compression process (a → b) in which the air is compressed in the compressor (11) to increase its pressure and temperature, and ii) the compressed high pressure and high temperature air is a high temperature heat exchanger (12). ) Is transferred to the external heat source 15 and the temperature decrease process (b → c) in which the temperature decreases under isostatic conditions, and iii) the air having a lowered temperature is expanded in the expander 13 so that the pressure and temperature are increased. Descending expansion process (c → d), and Ⅳ) Temperature rising process in which the temperature and pressure lowered air receives heat from the external heat source 16 in the low temperature heat exchanger 14 and the temperature rises under isostatic conditions. d → a).

At this time, a compression work for driving the compressor is required in the compression process (a → b), and an expansion work is generated from the expander in the expansion process (c → d), thereby reducing the required power of the compressor by returning it to the compressor. Can be.

In addition, in the temperature lowering process (b → c) or the temperature raising process (d → a), the external heat sources 15 and 16 correspond to air conditioning spaces. It serves to heat or cool the space.

Cooling capacity (Q) and Coefficient of Performance (COP) of the entire air cycle can be expressed as follows.

<Equation 1>

Until now, the description has been made of the sealed system, but in the air cycle, since the air itself becomes a refrigerant, an open system that directly uses the cycled air for cooling can be considered.

4 shows a schematic configuration diagram of an air cycle as an open system.

As shown in FIG. 4, the air cycle as an open system has no low-temperature heat exchanger 14, and cooling can be realized by directly supplying cool air flowing out of the expander 13 directly to the air conditioning space 15. .

On the other hand, in order to improve the efficiency of the system, an air cycle as an open system equipped with a regenerator can be considered.

5 shows a schematic diagram of an air cycle as an open system equipped with a regenerator.

In this case, as shown in FIG. 5, the air whose temperature is lowered in the high temperature heat exchanger 12 is heat-exchanged in the regenerator 17 and the cold air that is circulated from the air conditioning space 15 and returns. Further reduced and introduced into the inflator 13, the air expanded through the inflator 13 is further reduced than without the regenerator 17.

Therefore, since the temperature of the air exiting the expander 13 is further reduced as compared with the case where there is no regenerator 17, a higher cooling or freezing effect can be obtained.

However, since the conventional air cycle does not have a structure capable of simultaneously cooling and heating, there is a demand for an air cycle capable of simultaneously cooling and heating in one system by a simpler configuration.

The present invention has been made to solve the above-described problems, in the cooling mode to pass the air circulating the air cycle to the expander to obtain a cooling effect, in the heating mode to pass the expansion valve to obtain a heating effect, It is an object of the present invention to provide a hot air pump system of an air cycle capable of simultaneously cooling and heating in one system by a simpler configuration.

In order to achieve the above object, the present invention provides a compressor for compressing air circulating in a cycle, a high temperature heat exchanger for exchanging air compressed by the compressor with an external heat source, and inflating air from the high temperature heat exchanger. An air cycle comprising an expander for supplying a space, and a regenerator for heat exchange between air flowing into the compressor from the air conditioning space and air moving from the high temperature heat exchanger to the expander. On the circulation path of the air between the tiles, a branching point is provided in which part of the air branches in the middle of the circulation and is directly supplied to the air conditioning space. On the circulation path of the air between the branch point and the air conditioning space, the air is enthalpy. Expansion valve is provided to expand to, by the branch amount adjusting means Characterized by controlling the amount of air to be branched from the starting point.

Here, the separation amount adjusting means includes a first valve for adjusting the amount of air moving from the branch point to the high temperature heat exchanger, and a second valve for adjusting the amount of air moving from the branch point to the expansion valve. Configured; Located at the branch point, preferably comprises a three-way valve for controlling the amount of air moving from the branch point to the high temperature heat exchanger and the amount of air moving from the branch point to the expansion valve at the same time.

Best Mode for Carrying Out the Invention An embodiment of an air cycle hot air pump system according to the present invention will now be described in detail with reference to the drawings.

FIG. 6 is a schematic configuration diagram of one embodiment of a hot air pump system according to the present invention, and FIG. 7 is a schematic diagram of another embodiment of a hot air pump system according to the present invention. A block diagram is shown, and in FIG. 8, a TS diagram of a hot air pump system according to the present invention is shown.

In the cooling mode, the embodiment shown in Fig. 6 uses two valves as branch amount adjusting means for branching air at a branch point between the compressor and the high temperature heat exchanger and adjusting the amount of air branched at the branch point. The air is passed through the expander to obtain a cooling effect, and in the heating mode, the expansion valve is passed to obtain a heating effect, thereby simultaneously cooling and heating in one system.

Since the principle of operation of the entire air cycle has already been described, it will be omitted and the branching of the air, the branch amount adjusting means and the expansion valve corresponding to the features of the present invention will be described in detail.

As shown in FIG. 6, the compressed air in the compressor 11 encounters the branch point 19 on the way to the high temperature heat exchanger 12.

Some of the air at the branch point 19 may continue to the high temperature heat exchanger 12, and some may be supplied directly to the air conditioning space 15.

On the moving path of air from the branch point 19 to the air conditioning space 15, an expansion valve 18 for isoenthalpy expansion of air is provided.

The branching amount of air at the branch point 19 can be adjusted by the branching amount adjusting means, and in FIG. 6, two valves are used as the branching amount adjusting means.

The two valves are provided on a first valve 20 located on a moving path from the branch point 19 to the high temperature heat exchanger 12 and on a moving path from the branch point 19 to the expansion valve 18. By configuring the located second valve 21, it is possible to adjust the branching amount of air.

Referring to the operation relationship of each component in this embodiment configured as described above are as follows.

In the cooling mode for achieving the cooling or refrigerating effect, the first valve 20 is opened and the second valve 21 is closed, centering on the branch point 19.

Therefore, the air flow is controlled by the air conditioning space 15 → regenerator 17 → compressor 11 → first valve 20 → high temperature heat exchanger 12 → regenerator 17 → expander as in the conventional air cycle. 13) → Since the air conditioning space 15 is in the order, the cooling or refrigeration effect can be obtained in the air conditioning space 15.

On the other hand, in the heating mode for obtaining the heating or warming effect, the first valve 20 is closed and the second valve 21 is opened, centering on the branch point 19.

Therefore, the air flows in the order of the air conditioning space 15 → regenerator 17 → compressor 11 → second valve 20 → expansion valve 18 → air conditioning space 15, and thus the air conditioning space 15 In the heating or heating effect can be obtained.

At this time, the regenerator 17 does not play a role of regeneration and is merely an air passage.

On the other hand, in the embodiment shown in Fig. 7, the three-way valve 22 located on the branch point 19 is used as the branch amount adjusting means.

The three-way valve 22 simultaneously adjusts the amount of air moving from the branch point 19 to the high temperature heat exchanger 12 and the amount of air moving from the branch point 19 to the expansion valve 18.

Therefore, in the cooling mode for achieving the cooling or refrigerating effect, the air exiting the compressor 11 is moved to the high temperature heat exchanger 12 via the three-way valve 22.

In this case, the air flows from the air conditioning space 15 to the regenerator 11 to the compressor 11 to the three-way valve 22 to the high temperature heat exchanger 12 to the regenerator 17 to the expander 13 to the air conditioning space 15. ), The cooling or refrigeration effect can be obtained in the air conditioning space 15.

On the other hand, in the heating mode for obtaining the heating or warming effect, the air exiting the compressor 11 is moved to the expansion valve 18 via the three-way valve 22.

Therefore, the air flows in the order of the air conditioning space 15 → regenerator 11 → compressor 11 → three-way valve 22 → expansion valve 18 → air conditioning space 15. Thus, heating or warming effect can be obtained.

8 shows a TS diagram in the present invention.

Referring to FIG. 8, in the present invention, the principle of simultaneously performing cooling and heating in one system may be more easily understood.

In the cooling mode, as in the conventional air cycle, the cooling or refrigeration effect is obtained through the process of (f → a → b → e → c → d).

In contrast, the heating mode undergoes a process of (a → b → c ').

Here, the process of (b → c ') corresponds to an isenthalpy expansion process in the expansion valve 18. In this isenthalpy expansion process, since the temperature does not decrease greatly, the exit c' side of the expansion valve 18 is The temperature becomes higher than the temperature at the inlet a side of the compressor 11.

Therefore, by supplying the air from the expansion valve 18 to the air conditioning space 15, it is possible to obtain the heating or warming effect of the air conditioning space (15).

The heating performance at this time can be expressed by the following equation.

<Equation 2>

The heating efficiency is always expressed as the following equation due to the enthalpy loss Δh ₃ generated when the air expands through the expansion valve 18, and therefore always has a value less than 1.0.

<Formula 3>

In the cooling mode and the heating mode, the difference between the inflator 13 and the inflation valve 18 is that the work occurs in the inflator 13 so that the change in inflation causes an isentropic change while in the inflation valve 18 Since it does not occur, the change in expansion causes isoenthalpy change.

Therefore, since the temperature does not drop greatly in the expansion at the expansion valve 18, it can be utilized as a heat source.

That is, in the cooling mode, the high-pressure air is expanded with isentropy to sufficiently reduce the temperature to obtain a cooling or refrigeration effect. In the heating mode, the high-pressure air is expanded with isoenthalpy to lower the temperature without significantly reducing the temperature. Or warming effect.

As described above, according to the hot air pump system of the air cycle according to the present invention, in the cooling mode, the air circulating through the air cycle is passed through the expander to obtain a cooling effect, and in the heating mode, the expansion valve is passed to obtain a heating effect. Therefore, the simpler configuration can provide an air cycle hot air pump system that can simultaneously perform cooling and heating in one system.

In addition, the present invention can be used as a commercial refrigerator or warmer, there is an effect that can provide a hot air pump system of the air cycle that can be used at the same time in the summer and winter for home or vehicle use.

Claims (3)

A compressor 11 for compressing air circulating in the cycle, a high temperature heat exchanger 12 for exchanging air compressed by the compressor 11 with an external heat source, and an air conditioner after expanding the air from the high temperature heat exchanger Between the inflator 13 supplied to the space 15 and the air flowing from the air conditioning space 15 into the compressor 11 and the air moving from the high temperature heat exchanger 12 to the expander 13. In an air cycle comprising a regenerator 17 for heat exchange, On the circulation path of the air between the compressor 11 and the high temperature heat exchanger 12, a branch point 19 is provided in which part of the air branches in the middle of circulation and is directly supplied to the air conditioning space 15. On the circulation path of the air between the branch point 19 and the air conditioning space 15, there is provided an expansion valve 18 for expanding the air by isenthalpy, Hot air heat pump system of the air cycle, characterized in that for controlling the amount of air branched from the branch point (19) by the branch amount adjusting means. The method of claim 1, The branch amount adjusting means includes a first valve 20 for adjusting an amount of air moving from the branch point 19 to the high temperature heat exchanger 12, and a branch valve 19 moving from the branch point 19 to the expansion valve 18. Hot air pump pump system of the air cycle characterized in that it comprises a second valve (21) for adjusting the amount of air. The method of claim 1, The branch amount adjusting means is located at the branch point 19 to move the amount of air moving from the branch point 19 to the high temperature heat exchanger 12 and to the expansion valve 18 from the branch point 19. Hot air pump system of the air cycle comprising a three-way valve (22) for controlling the amount of air at the same time.

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