JP2001174078A - Controlling device of outlet-side refrigerant of evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a means that can sufficiently secure the performance of an evaporator, can make uniform the temperature distribution of an air-side outlet, can suppress the pressure loss of a refrigerant side for preventing the amount of the circulation of a refrigerant from being reduced, and can introduce the refrigerant to a compressor as a super heat gas in a refrigeration cycle using a temperature-type expansion valve as the reduced pressure expansion means of a liquid refrigerant being sent to the evaporator. SOLUTION: In a refrigerant channel 6a from the outlet of an evaporator 5 to a thermally sensitive part 42 of a temperature-type expansion valve 41, a heating means 8A is interposed, where the heating means 8 adds super heat to a refrigerant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a refrigerant at an evaporator outlet side in a refrigeration cycle in which a temperature type expansion valve is interposed in a refrigerant flow path at an evaporator inlet side.

[0002]

2. Description of the Related Art Generally, in a refrigeration cycle of a car air conditioner or the like, as shown in FIG. 5, a high-temperature and high-pressure gas refrigerant discharged from a compressor (1) enters a condenser (2) and is forcibly removed from outside air. It cools by heat exchange, condenses and liquefies, flows into the receiver tank (3) in a supercooled (subcooled) state, and only the liquid refrigerant is discharged from the receiver tank (3).
It is rapidly expanded by the decompression and expansion means (4), enters the evaporator (5), and in the process of flowing as a low-pressure and low-temperature mist-like refrigerant, takes away latent heat for evaporation from the surrounding air and evaporates vigorously. The cooled air is sent to a required part to perform a cooling action.

[0003] The refrigerant that has exited the evaporator (5) is returned to the compressor (1), and is sent again to the condenser (2) as a high-temperature and high-pressure gas refrigerant as described above. The refrigerant entering (1) must be completely gaseous in order to prevent liquid compression. For this reason, in a refrigeration cycle using a temperature type expansion valve as the pressure reducing expansion means (4),
Based on the temperature of the outlet refrigerant detected via the temperature-sensitive cylinder (4a) provided near the evaporator outlet in the refrigerant flow path (6) from the evaporator (5) to the compressor (1), the evaporator ( 5) The orifice opening of the expansion valve is set so that the vicinity of the outlet side in the inside becomes a superheat portion, and the refrigerant is led out as superheat gas (superheated steam) from the outlet of the evaporator (5). It is common.

[0004]

However, when the superheat section is formed in the evaporator as described above, the latent heat component of the liquid refrigerant component cannot be used for heat exchange in the superheat section. As the temperature distribution at the air side outlet becomes non-uniform, the pressure loss on the refrigerant side increases due to the sudden increase in specific volume in the superheat section,
This causes a reduction in the amount of circulating refrigerant, resulting in a reduction in the performance of the evaporator, and also has a problem in that the degree of freedom in design is reduced due to restrictions on the configuration of the refrigerant circuit in the evaporator.

SUMMARY OF THE INVENTION In view of the above circumstances, the present invention provides a refrigeration cycle using a temperature-type expansion valve as a means for reducing and expanding a liquid refrigerant sent to an evaporator. Aiming to provide a means for making the temperature distribution uniform, suppressing pressure loss on the refrigerant side, preventing a decrease in the amount of refrigerant circulating, and guiding the refrigerant as a superheat gas to the compressor. I have.

[0006]

In order to achieve the above object, the present invention is directed to a refrigeration cycle in which a temperature type expansion valve is interposed in a refrigerant flow path on the inlet side of an evaporator. The gist of the present invention is a control device for an evaporator outlet-side refrigerant, in which a heating means for applying superheat to the refrigerant is interposed in a refrigerant flow path from the to a temperature-sensitive part of a temperature-type expansion valve.

That is, according to the above configuration, the superheat can be applied to the refrigerant flowing through the refrigerant flow path by the heating means interposed in the refrigerant flow path from the outlet of the evaporator to the temperature sensing portion of the temperature type expansion valve. Therefore, it is possible to guide the refrigerant as a superheat gas to the compressor without forming a superheat section inside the evaporator. Therefore, by controlling the superheat portion in the evaporator to be reduced or removed by the temperature type expansion valve, the latent heat component of the liquid refrigerant component is used for heat exchange to the vicinity of the outlet in the evaporator. By setting, the temperature distribution at the air-side outlet can be made uniform, and the pressure loss on the refrigerant side can be suppressed to improve the intrinsic performance of the evaporator.

According to the second aspect of the present invention, in the control device for the refrigerant on the evaporator outlet side according to the first aspect, the heating means is a heater, so that the refrigerant guided to the compressor is surely a superheat gas. It becomes possible.

According to a third aspect of the present invention, in the control device for an evaporator outlet-side refrigerant according to the first aspect, the refrigerant flow path from the outlet of the evaporator to the temperature-sensitive portion of the thermal expansion valve is provided with air to the evaporator. A pipe is provided via the inflow area, and a heat receiving fin is provided at a portion of the pipe passing through the air inflow area, and the heating means is provided between the inlet air to the evaporator and the refrigerant via the heat receiving fin. Heat exchange is to be performed. In this case, since the inlet air flowing into the evaporator can be used as a heat source for taking superheat outside the evaporator, it is not necessary to use a separate heating heat source.

According to a fourth aspect of the present invention, in the control apparatus for an evaporator outlet-side refrigerant according to the first aspect, the refrigerant pipe extending from the condenser to the thermal expansion valve, and the temperature sensing of the thermal expansion valve from the evaporator outlet. The heating means performs heat exchange between the refrigerants in the two pipes at the pipe contact portion. In this case, the refrigerant flowing in the refrigerant pipe from the condenser to the temperature type expansion valve has a high temperature and a high pressure, whereas the refrigerant flowing in the refrigerant pipe from the outlet of the evaporator to the temperature sensitive part of the temperature type expansion valve has a low temperature. Since the temperature difference is large at low pressure, the heat exchange at the pipe contact area
The refrigerant in the latter pipe can be surely turned into a superheat gas, and the refrigerant in the former pipe also has an increased degree of subcooling (supercooling).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a control device for an evaporator outlet-side refrigerant according to the present invention will be specifically described below with reference to the drawings. 1 shows a first embodiment, FIG. 2 shows a second embodiment, FIG. 3 shows a third embodiment, and FIG. 4 shows a fifth embodiment.

In the first embodiment shown in FIG. 1, an inlet-side refrigerant flow path (7) from the condenser (not shown) side to the inlet of the evaporator (5), and a compressor from the outlet of the evaporator (5). An expansion valve unit (40) including a temperature-sensitive part (42) of a temperature-type expansion valve (41) is attached to a portion close to the outlet-side refrigerant flow path (6) toward a machine (not shown). Side refrigerant channel (6)
In the middle of the refrigerant flow path (6a) from the evaporator (5) to the temperature sensing part (42) of the temperature-type expansion valve (41) in the heater (8).
A) is interposed.

In the second embodiment shown in FIG. 2, the flow path configuration including the expansion valve unit (40) of the inlet side refrigerant flow path (7) and the outlet side refrigerant flow path (6) is the same as that of the first embodiment. Same as above, except that a heater (8B) is attached to the outside of the evaporator (5), and the refrigerant flow path (6a) from the outlet of the evaporator (5) passes through the heater (8B) to the outside. To reach the temperature sensing part (42) of the temperature type expansion valve (41).

In the constructions of the first and second embodiments, the superheat is given to the refrigerant exiting the evaporator (5) by heating by the heaters (8A) and (8B), and the refrigerant is completely superheated. Compressor (not shown) as gas
Can lead to Therefore, in the evaporator (5), the superheat portion inside the evaporator (41) is controlled so as to be reduced or removed by the temperature type expansion valve (41). By making the evaporator usable for replacement, it is possible to equalize the temperature distribution at the air-side outlet and suppress the pressure loss at the refrigerant side, thereby improving the intrinsic performance of the evaporator.

The type of the heaters (8A) and (8B) is not particularly limited, but an electrothermal type is recommended because it is structurally simple and easy to mount. In particular, as the heater (8) interposed in the middle of the refrigerant channel (6a) as in the first embodiment, the simplest method is to wind a heating wire around the pipe of the channel (6a). Then
It is desirable to control the output of these heaters (8A) (8B) in accordance with the refrigerant flow rate so as to keep the superheat of the refrigerant constant.

In the third embodiment, as shown in FIG. 3 (A), as in the first and second embodiments, an inlet-side refrigerant flow path (7) leading to the inlet of the evaporator (5) is provided. An expansion valve unit (40) including a temperature-sensitive portion (42) of a temperature-type expansion valve (41) is attached to a portion where the refrigerant flow path (6) on the outlet side from the outlet of the evaporator (5) approaches. ing. Thus, the piping (61) of the refrigerant flow path (6a) from the evaporator (5) to the temperature sensing part (42) of the temperature type expansion valve (41) in the outlet side refrigerant flow path (6) is shown in FIG. As shown by the large arrow (9), the heat exchange air passing through the evaporator (5) passes through the air inflow area (90) to the evaporator (5) and passes through the air inflow area (90). A heat receiving fin (10A) is provided in the portion.

In the configuration of the third embodiment, the inlet air before the heat exchange in the air inflow area (90) is much higher than the temperature of the refrigerant exiting the evaporator (5). When the refrigerant flowing through the air passes through the air inflow area (90), the refrigerant exchanges heat with the inlet air through the heat receiving fins (10A), thereby leading the refrigerant to a compressor (not shown) as a superheat gas. it can. Therefore, similarly to the first and second embodiments, the superheated portion inside the evaporator (5) is controlled by the thermal expansion valve (41) so as to be reduced or eliminated, and the air side outlet is controlled. The inherent performance of the evaporator can be improved by making the temperature distribution uniform and suppressing the pressure loss on the refrigerant side.

The heat receiving fin (10) shown in FIG.
A) shows a flange-shaped radial fin. Instead, a strip-shaped fin (10B) radially arranged around a pipe (61) as shown in FIG. Various forms of heat receiving, such as meandering fins (10C) arranged so as to sandwich the flat part (61a) of the pipe (61) and providing the cover (11) on the outside as shown in FIG. Fins can be employed.

In the fourth embodiment shown in FIG. 4, as in the first to third embodiments, the inlet-side refrigerant flowing from the condenser (2) to the inlet of the evaporator (5) via the receiver tank (3). The temperature-sensitive part (41) of the temperature-type expansion valve (41) is located in a portion where the flow path (7) and the outlet-side refrigerant flow path (6) from the outlet of the evaporator (5) to the compressor (1) are close to each other. An expansion valve unit (40), including 42), is mounted. The evaporator (5) in the outlet-side refrigerant flow path (6) is connected to the thermal expansion valve (41).
A pipe contact part (12) is provided in the middle of the refrigerant flow path (6a) up to the temperature sensing part (42). In the pipe contact part (12), the pipe (61) of the refrigerant flow path (6a) is provided. ) Is configured to be in contact with a pipe (71) extending from the receiver tank (3) in the introduction-side refrigerant flow path (7) to the temperature-type expansion valve (41).

In the structure of the fourth embodiment, the refrigerant flowing in the pipe (71) has a high temperature and a high pressure, while the refrigerant flowing in the pipe (61) has a low temperature and a low pressure and a large temperature difference. Both pipes (61) at the pipe contact area (12)
Heat exchange is performed between the refrigerant flowing in (71) and piping (61)
The refrigerant inside receives the heat to surely become a superheat gas, and the refrigerant in the pipe (71) is deprived of heat, and the degree of subcooling (supercooling) increases. In this case, the superheat section in the evaporator (5) can be reduced or eliminated to improve the intrinsic performance of the evaporator as in the first to third embodiments, but the temperature type expansion valve (41) can be used. The subcooling of the liquid refrigerant supplied to the evaporator (5) is also high.
Therefore, the evaporator (5) exhibits more excellent heat exchange performance.

In the present invention, the evaporator (5)
Heating means other than those exemplified in the first to fourth embodiments may be used as a heating means interposed in the refrigerant flow passage from the outlet of the thermostatic expansion valve (41) to the temperature sensing portion (42) of the temperature type expansion valve (41). Various heating means can be employed. In the first to fourth embodiments, the temperature type expansion valve (41) and its temperature sensing part (42) are integrated into the expansion valve unit (40). It may have a separated configuration. Further, there is no particular limitation on the type and structure of the evaporator (5).

[0022]

According to the first aspect of the present invention, there is provided a refrigeration cycle using a temperature type expansion valve as a means for reducing and expanding a liquid refrigerant to be sent to an evaporator.
Since a heating means for applying superheat to the refrigerant is interposed in the refrigerant flow path from the outlet of the evaporator to the temperature-sensitive part of the temperature-type expansion valve, the refrigerant can be provided without forming a superheat part inside the evaporator. To the compressor as a superheat gas, and the temperature-type expansion valve controls the superheat section in the evaporator to be reduced or eliminated, making the temperature distribution at the air side outlet uniform and In addition, the pressure loss on the refrigerant side can be suppressed to prevent a decrease in the amount of circulating refrigerant, thereby improving the intrinsic performance of the evaporator.

According to the second aspect of the present invention, in the evaporator outlet-side refrigerant control device, since a heater is used as the heating means, superheat can be reliably applied to the refrigerant guided to the compressor.

According to the third aspect of the present invention, in the control device for the refrigerant on the outlet side of the evaporator, the refrigerant flow path from the outlet of the evaporator to the temperature sensing part of the temperature type expansion valve flows into the evaporator. Since the heat is exchanged between the refrigerant and the inlet air to the evaporator through the heat receiving fins provided in the air inflow area of the pipe, the heat exchange is performed outside the evaporator. Therefore, there is no need to use a separate heat source for heating in order to take the superheat, and there is an advantage that an increase in operating cost due to the heating means can be avoided.

According to the fourth aspect of the present invention, in the control device for the refrigerant on the outlet side of the evaporator, the refrigerant pipe from the condenser to the thermal expansion valve, and the temperature sensing part of the thermal expansion valve from the outlet of the evaporator. And superheat is applied to the refrigerant in the latter pipe by simultaneously exchanging heat between the refrigerants in both pipes at this contact portion, and at the same time, the refrigerant in the former pipe is Since the degree of subcooling is increased, the performance of the evaporator is further improved.

[Brief description of the drawings]

FIG. 1 is a refrigerant circuit diagram showing an evaporator outlet-side refrigerant control device according to a first embodiment of the present invention.

FIG. 2 is a refrigerant circuit diagram showing an evaporator outlet-side refrigerant control device according to the second embodiment.

FIG. 3 shows a control device for the evaporator outlet side refrigerant according to the third embodiment, FIG. 3 (A) is a refrigerant circuit diagram, and FIG. 3 (B) is a longitudinal section showing another configuration of a heat receiving fin used in the control device. Side view,
(C) is a side view which shows further another structure of the heat receiving fin.

FIG. 4 is a refrigerant circuit diagram of the entire refrigeration cycle showing the control device for the evaporator outlet-side refrigerant according to the fourth embodiment.

FIG. 5 is a refrigerant circuit diagram showing a basic principle of a refrigeration cycle.

[Explanation of symbols]

1 ... Compressor 2 ... Condenser 3 ... Receiver tank 5 ... Evaporator 40 ... ······· Expansion valve unit 41 ······ Temperature expansion valve 42 ··········································································································································· 6a ························ Piping 7 ······················ Introducing refrigerant path (condenser) …………………………………………………………………………………… Pipes 8A, 8B… ················ Heat exchange air 90 ········ ... Air inflow area 10A to 10C ... Heat receiving fins (Heating means) 12 ... Pipe contact part (Heating means)

Claims (4)

[Claims] In a refrigeration cycle in which a temperature type expansion valve is interposed in a refrigerant flow path on an evaporator inlet side, a supercooled refrigerant flows in a refrigerant flow path from an outlet of the evaporator to a temperature sensing part of the temperature type expansion valve. An evaporator outlet-side refrigerant control device including a heating means for applying heat. 2. The heating device according to claim 1, wherein said heating means is a heater.
A control device for an evaporator outlet-side refrigerant as described in the above. 3. A refrigerant flow path from an outlet of the evaporator to a temperature sensing part of the temperature type expansion valve is piped through an air inflow area to the evaporator, and a portion of the pipe passing through the air inflow area. The evaporator outlet-side refrigerant control device according to claim 1, wherein a heat receiving fin is provided, and the heating means exchanges heat between the refrigerant and the inlet air to the evaporator via the heat receiving fin. . 4. A piping contact portion between a refrigerant pipe extending from a condenser to a thermal expansion valve and a refrigerant piping extending from an outlet of an evaporator to a temperature-sensitive section of the thermal expansion valve, wherein the heating means is connected to the piping. The evaporator outlet-side refrigerant control device according to claim 1, wherein heat exchange is performed between the refrigerants in the two pipes at the contact portion.