KR20090128342A - An 4pass tube-fin type heat exchanger using refrigerant containing hfo 1234yf - Google Patents

Abstract

PURPOSE: An air conditioning system for a vehicle using a 4 pass tube-fin type evaporator using HFO 1234yf material refrigerant is provided to acquire evaporator performance even using HFO 1234yf material refrigerant. CONSTITUTION: An air conditioning system for a vehicle comprises a compressor, a condenser, an expansion valve, and an evaporator(100). The evaporator comprises a plurality of tubes(20), fins(30), a pair of header tanks(10), and more than one baffle. The fins inserted between the tubes increases a heat transfer area with air which is flowed between the tubes. The header tanks coupled with both ends of the tubes distribute heat exchange media composed of HFO 1234yf. The height of the tubes ranges from 2.4889mm to 4.082mm, and the flow of the heat exchange media is composed of 4paths.

Description

HFO 1234ｙｆ Automotive air conditioning system using a 4-pass tube-pin type evaporator using a refrigerant [An 4Pass Tube-Fin Type Heat Exchanger using Refrigerant containing HFO 1234yf}

The present invention relates to a vehicle air conditioning system using a 4-pass tube-pin type evaporator using an HFO 1234yf material refrigerant, and more particularly, to use an HFO 1234yf material refrigerant having properties different from those of the conventional refrigerant. The design of a vehicle air conditioning system using a four-pass tube-pin type evaporator to achieve the performance.

As environmental problems are raised around the world, the use of substances harmful to the environment is gradually being banned or excluded. In particular, in refrigerants essential for air conditioning and cooling systems, materials such as CFC-based refrigerants, which contain chlorine components, are increasingly regulated due to their ozone depleting properties.

A typical cooling system consists of an evaporator that absorbs heat from the surroundings, a compressor that compresses the refrigerant, a condenser that releases heat to the surroundings, and an expansion valve that expands the refrigerant. In the cooling system, the gaseous refrigerant flowing from the evaporator to the compressor is compressed at a high temperature and high pressure in the compressor, the liquefied heat is released to the surroundings in the process of liquefaction of the compressed gaseous refrigerant passing through the condenser, the liquefaction The refrigerant passes through the expansion valve again to become a low-temperature and low-pressure wetted vapor state, and then flows back into the evaporator and vaporizes, thereby cooling the ambient air by absorbing vaporization heat from the surroundings, thereby forming a cooling cycle. FIG. 1B is a simplified illustration of the p-h diagram of this general air conditioning system.

In such a cooling system, the actual heat transfer is a refrigerant, and it is natural that the material used as the refrigerant should have high heat transfer characteristics. In the case of the conventional CFC-based refrigerants, such heat transfer characteristics are pointed out that they have a harmful effect on the environment, and their use is regulated. Therefore, various studies on new refrigerants that can replace conventional refrigerants and Development is active. In order for new refrigerants to be able to replace conventional refrigerants, they must have the same or superior level of heat transfer characteristics, chemical stability, non-flammability and lubrication compatibility as compared to conventional refrigerants, as well as eco-friendliness. Is true.

Korean Patent Publication No. 2007-0004654 ("fluorine substituted olefin containing composition", hereinafter referred to in the prior art) discloses a new refrigerant having excellent performance enough to replace the conventional refrigerant as described above. The refrigerant using HFO 1234yf material among the refrigerants proposed in the prior art is hereinafter referred to as 1234yf refrigerant. The term "HFO-1234" is used herein to refer to all tetrafluoropropenes. Among the tetrafluoropropenes are HFO-1234yf and cis- and trans-1,1,1,3-tetrafluoropropene (HFO-1234ze). HFO-1234 compound is a known substance and is registered in the Chemical Abstracts database. US Patent No. 2,889,379; By 4,798,818 and 4,465,786 discloses a fluorine-containing C ₃ compounds are a large variety of saturated or unsaturated halogen catalyst vaporized, it is described with respect to the production of propene fluoroalkyl such as CF ₃ CH = CH _2. EP 974,571 also discloses contacting 1,1,1,3,3, -pentafluoropropane (HFC-245fa) with a chromium-based catalyst in high temperature, vapor phase, or in liquid phase, KOH, NaOH, Ca (OH). ₂ ) or 1,1,1,3-tetrafluoropropene is described by contact with an alcohol solution of Mg (OH) ₂ .

1 (A) is a p-h diagram of the R-134a refrigerant and the 1234yf refrigerant, which are representative refrigerants widely used in the related art. As shown, the ph diagrams of the R-134a refrigerant and the 1234yf refrigerant are different from each other. More specifically, the physical properties of the 1234yf refrigerant and the operating pressure / operating temperature in the air conditioning system have values similar to those of the conventional R-134a refrigerant. However, the latent heat of evaporation of the 1234yf refrigerant is about 30% smaller than the latent heat of evaporation of the R-134a refrigerant, and it can be seen that more refrigerant flow rate is required to have a heat dissipation performance equivalent to that of the R-134a refrigerant.

In the past, many studies have been conducted to optimize the performance of the evaporator, that is, the amount of heat radiation, the pressure drop, and the like in an evaporator using a refrigerant such as R-134a. However, in the case of the 1234yf refrigerant, as shown in FIG. 1 (A), since the evaporator using the 1234yf refrigerant has the same performance as that of the conventional refrigerant, it is very different from the conventional refrigerant. Naturally, it requires a completely different design from the evaporator. In fact, when 1234yf refrigerant is used in an evaporator with the same specifications as an evaporator using R-134a refrigerant, the refrigerant flow rate must be increased to obtain equivalent heat dissipation performance. The refrigerant pressure drop is excessively increased, and thus the overall performance of the air conditioning system is greatly reduced.

That is, while the 1234yf refrigerant is an environmentally friendly material as compared to the R-134a refrigerant as described above, it has been pointed out that the 1234yf system has a lower performance than the R-134a system, and much research and development is required to overcome this. The point is well known. In order to overcome such a performance difference, various variables can be optimized in the system, and considering the economic cost increase caused by the system change, it is desirable to have the best performance improvement without large design changes compared to the existing system. The point is natural. At this time, the present invention seeks to find a solution that can satisfy the demand for improving the performance by optimizing the numerical range of the evaporator components, that is, without significant design changes compared to the existing system.

Therefore, the present invention has been made to solve the problems of the prior art as described above, the object of the present invention is a HFO 1234yf material refrigerant with a completely different physical properties from the conventional refrigerants such as R-134a, CO ₂ In the evaporator using the, to provide a vehicle air conditioning system using a four-pass tube-pin type evaporator using the HFO 1234yf material refrigerant having a design matter optimized for the material properties of the refrigerant.

An air conditioning system for a vehicle using a four-pass tube-pin type evaporator using the HFO 1234yf material refrigerant of the present invention for achieving the above object, the compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10, The heat exchange medium is a refrigerant comprising a HFO 1234yf material, the tube height H _t has a value in the range of 2.489mm to 4.082mm, the flow of the heat exchange medium is a tube-pin type evaporator (100) consisting of four passes; Characterized in that consisting of a refrigerant circuit comprising a. At this time, it is more preferable that the tube height H _t has a value within the range of 2.875 mm to 3.711 mm.

Alternatively, a vehicle air conditioning system using a four-pass tube-pin type evaporator using the HFO 1234yf material refrigerant of the present invention includes a compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10, The heat exchange medium is a refrigerant comprising a HFO 1234yf material, the tube hydraulic diameter D _t has a value in the range of 0.780mm to 1.839mm, the flow of the heat exchange medium is a tube-pin type evaporator (100) consisting of four passes; Characterized in that consisting of a refrigerant circuit comprising a. At this time, it is more preferable that the tube hydraulic diameter D _t has a value within the range of 0.946 mm to 1.775 mm.

Alternatively, a vehicle air conditioning system using a four-pass tube-pin type evaporator using the HFO 1234yf material refrigerant of the present invention includes a compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10. The heat exchange medium is a refrigerant comprising HFO 1234yf material, and the acid or bone number FPDM of the fins per decimeter has a value in the range of 63.439 to 88.897, and the flow of the heat exchange medium is a 4-pass tube-pin type evaporator. 100; Characterized in that consisting of a refrigerant circuit comprising a. At this time, the FPDM more preferably has a value in the range of 65.190 to 88.897.

In addition, the evaporator 100 has a first tube group (①-4) to the fourth tube group (④-4) is formed between the baffles provided in the upper and lower tanks of the first row and the second row, the heat exchange The medium is characterized in that passing through the first tube group (①-4) to the fourth tube group (④-4) in sequence.

According to the present invention, in a vehicle air conditioning system using a four-pass tube-pin type evaporator using the HFO 1234yf material refrigerant, the HFO 1234yf material refrigerant is completely different from the conventional refrigerants such as R-134a, CO _2, etc. Therefore, by solving the problem that the best performance can not be obtained with the conventional evaporator, there is an effect of optimizing the performance of the evaporator, that is, the amount of heat radiation and pressure drop. That is, according to the evaporator of the present invention, the same level of performance as the conventional evaporator can be obtained while using the 1234yf refrigerant.

In particular, according to the present invention, it is possible to maintain the same level of performance as compared to an evaporator using a refrigerant such as R-134a while using a refrigerant having excellent eco-friendliness, to secure the evaporator performance and at the same time obtain a high eco-friendliness There is a big effect that can be done. In addition, it was well known that the conventional 1234yf system is inferior in performance to the R-134a system, and in order to overcome this, there may be a problem of economic cost increase due to the design change as a whole, but in the case of the present invention, only the design value of the evaporator is used. By changing only the range, a 1234yf system can be obtained that achieves the same level of performance as the R-134a system.

Hereinafter, a vehicle air conditioning system using a 4-pass tube-pin type evaporator using the HFO 1234yf material refrigerant according to the present invention having the configuration as described above will be described in detail with reference to the accompanying drawings.

Figure 2 shows the shape of a typical tube-pin type evaporator. The general tube-pin type evaporator 100 includes a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction; A fin (30) interposed between the tubes (20) and increasing a heat transfer area with air flowing between the tubes (20); A pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows; It is made, including.

In such tube-pin type evaporators, the refrigerant generally consists of four passes or six passes. Figure 3 shows a form in which a four-pass refrigerant flow in the tube fin type evaporator. As shown in FIG. 2, the tube-pin type evaporator is generally composed of two rows, and in FIG. 3, each row is separated to simplify the display of the refrigerant flow, and the tank and tube parts are simplified. As shown in FIG. 3, in the case of four passes, two different directions of refrigerant flow are generated per column, and four refrigerant flow directions are formed as a whole. In order to switch the refrigerant flow in this way, as illustrated in a simplified manner in FIG. 3, the tank is provided with a baffle 40 inserted at an appropriate position. That is, in the four-pass evaporator, the first tube group (①-4) to the fourth tube group (④-4) is formed with the baffles provided in the upper and lower tanks of the first row and the second row, and the heat exchange medium is The first tube group (①-4) to the fourth tube group (④-4) is to pass sequentially.

An embodiment of the refrigerant flow in the four-pass evaporator as shown in FIG. 3 will be described in more detail as follows. First, as shown in FIG. 3, the side into which the refrigerant flows in is the first row, and the side through which the refrigerant is discharged into the second row. The reference numerals of the lower tanks are denoted by 11b, the second row upper tanks are denoted by 12a, and the second row lower tanks are denoted by reference numeral 12b. Further, reference numerals of the first row tubes are denoted by 21 and reference numerals of the second row tubes are denoted by 22. At this time, the baffle 40 is provided with one in each tank as shown. The refrigerant flow in the four-pass evaporator flows into the first row upper tank 11a, and the front part of the baffle 40 provided in the first row upper tank 11a of the first row upper tank 11a-the first. First tube group (①-4) that is part of the row tube 21-First row lower tank 11b-Second tube group (②-4) which is part of the first row tube 21-First row upper tank 11a After passing through the tank and tube of the first row by sequentially passing through the rear portion of the baffle 40 provided in the first row of the upper tank (11a) of the first row, and now flows to the second row, the second row of the upper tank (12a) Rear portion of the baffle 40 provided in the second row upper tank 12a of the second row; the third group of tubes (③-4); and the second row of the lower row tanks 12b; (22) part of the fourth tube group ④-4-the second row of tanks by sequentially passing the front portion of the baffle 40 provided in the second row of upper tanks 12a of the second row of upper tanks 12a; After passing through the tube, it is discharged from the second row upper tank 12a.

Of course, a four pass evaporator does not necessarily constitute a flow path in this manner. For example, as long as the flow path is configured so that the coolant flows into four passes, such as the inflow and discharge of the coolant from the lower tank, the coolant flow may be performed in some different forms from the example of FIG. 3. A pass evaporator can be included.

In the case of 4 pass and 6 pass, even though the same refrigerant and the same size evaporator are used, the heat exchange characteristics are different. Therefore, in order to optimize the characteristics such as heat dissipation performance and pressure drop, it is necessary to distinguish how many passes the refrigerant flows. . In the present invention, the heat exchange performance of the four-pass tube-pin type evaporator as shown in FIG. 3 is to be optimized. Therefore, the term 'evaporator' below indicates that it refers to a four-pass tube-pin type evaporator.

Figure 4 shows each detailed shape of the evaporator. 4 (A) shows a part of the evaporator core consisting of the tube 20 and the fin 30, FIG. 4 (B) shows a cross section of the tube 20, and FIG. 4 (C) ) Is a cross-sectional view of the section AA ′ of FIG. 2, ie, a portion in which the width center line of the header tank 10 is cut in the longitudinal direction. As shown in FIG. 4C, a partition wall extending in the longitudinal direction to separate the inside of the header tank 10 is formed in a widthwise centerline portion of the header tank 10, and on the partition wall according to a flow path design. Communication holes may be formed.

As shown in FIGS. 4A and 4B, the height of the tube 20 is referred to as H _t . In addition, the sum of the areas of the respective portions of the tube 20 passing through the heat exchange medium, that is, the flow path area of the tube 20 is S _t . In addition, the sum of the circumferential lengths of each portion (that is, the flow area area portion) through which the heat exchange medium flows on the tube 20 end surface, that is, the receiving length is referred to as L _t . In addition, the area of the communication hole shown in FIG. At this time, the hydraulic diameter D _t of the tube 20 is 4S _t / L _t . Tubes used in the evaporator using the conventional R-134a refrigerant has a variety of types, such as extruded, folded, welded, etc., but also in the evaporator using the HFO 1234yf refrigerant of the present invention extruded, folded Various types of tubes, such as welded type, can be applied.

In the present invention, more than a predetermined ratio (98% to 99%) of the heat dissipation performance compared to the evaporator using the R-134a refrigerant, a predetermined ratio (90% to 95%) or less of the refrigerant pressure drop, and an equivalent level of the air pressure drop (100%) Each design parameter value of the evaporator using 1234yf refrigerant, which is below), was optimized. Tube height H _t ranges from 1.4mm to 3.6mm, tube hydraulic diameter D _t ranges from 0.97mm to 1.89mm, and FPDM (number of peaks or valleys per pin in one decimeter, 10cm (1 / 10m)) ranges from 60 to 84 , Through the performance test with a combination of parts of 110mm ² ~ 450mm ² to obtain a result graph as shown in Figs. 5-7, based on this, each design to optimize the performance of the evaporator using 1234yf refrigerant The numerical value of the variable was obtained. In each of the graphs of FIGS. 5 to 7, the heat radiation performance Q, the refrigerant pressure drop amount dP _ref , and the air pressure drop amount dP _air are 100 kW (measured value-minimum value among measured values) / maximum value among measured values. The values are expressed as dimensionless values.

There are two types of tests: unit test and air conditioner system test. Single unit test is to test the performance by circulating the refrigerant while the inlet and outlet pressure of the evaporator is fixed, and the air conditioner system test is to test the performance while changing the condition of the compressor RPM and intake air in the air conditioner system mounted on the actual vehicle. will be. In this case, a good result in a single product test does not necessarily give a good result in a system test because it is affected by driving conditions.

FIG. 8A is a graph illustrating a relationship between a single component heat dissipation performance and an air conditioning system performance (discharge air temperature) according to various types of HFO 1234yf cores, and FIG. 8B is a single component refrigerant pressure drop amount and an air conditioning system performance according to various types of HFO 1234yf cores (FIG. Discharge air temperature). The graphs of FIGS. 8A and 8B are results for a single unit test, and each result will be described in more detail below.

FIG. 8A shows a result of a single-piece test on various types of HFO 1234yf cores having different heat dissipation performance. In FIG. 8A, the x-axis shows heat dissipation performance according to various types of cores, and the y-axis shows discharge air temperature. As a performance indicator, the lower the better. Each result graph shown in FIG. 8A shows the discharge air temperature for each traveling speed of the vehicle. As can be seen from the graph, the heat dissipation performance of the unit is optimal at 99% or more, and the performance is deteriorated at 99% or less.

FIG. 8B shows a result of a single unit test on various types of cores for HFO 1234yf having different refrigerant pressure drop amounts. In FIG. 8B, the x-axis is a refrigerant pressure drop amount according to various types of cores, and the y-axis is also the discharge air temperature. In addition, each result graph also shows the discharge air temperature according to the traveling speed of the vehicle. Also in the graph of FIG. 8B, it can be seen that the coolant-side pressure drop amount of the single part deteriorates rapidly at all conditions except for an idle state.

In the present invention, through the system test, the heat dissipation performance and the refrigerant pressure drop amount in the core for R-134a is set to 100% with respect to the heat dissipation performance and the refrigerant pressure drop amount showing the optimal system performance in using the core for the HFO 1234yf. The extent was calculated and the range of tube height, hydraulic diameter, and FPDM of the evaporator corresponding to the% value of the heat radiation performance and the refrigerant pressure drop amount was determined.

5 is a graph showing the relationship between the tube height H _t , the heat dissipation performance, and the refrigerant pressure drop in the evaporator using the HFO 1234yf refrigerant. The heat radiation performance Q and the refrigerant pressure drop amount dP _ref vary greatly as shown in FIG. 5 with the change of the tube height H _t , but the air pressure drop amount dP _air is not shown. Did.

In FIG. 5A, the heat dissipation performance Q is 99% or more and the refrigerant pressure drop dP _ref is 90% or less as compared with an evaporator using a R-134a refrigerant. . As shown, the upper limit of the tube height H _t is determined to be 3.711 mm by the heat dissipation performance (Q) constraint, and the lower limit of the tube height H _t is determined to be 2.875 mm by the refrigerant pressure drop (dP _ref ) constraint. do.

In FIG. 5B, the heat dissipation performance Q is 98% or more and the refrigerant pressure drop dP _ref is 95% or less as compared with an evaporator using the R-134a refrigerant. . Determining the lower limit of the heat radiation performance (Q) by the upper limit value of the constraint tube height H _t is decided to 4.082mm, the refrigerant-side pressure drop (dP _ref) by the constraint tube height H _t is a 2.489mm, as illustrated do.

That is, it is preferable that the tube height H _t of the evaporator using the 1234yf refrigerant has a value within the range of 2.489 mm to 4.082 mm (heat dissipation performance (Q) of 98% or more, refrigerant side pressure drop (dP _ref ) of 95% or less), It is more preferable to have a value (99% or more of heat radiation performance Q and 90% or less of refrigerant | coolant side pressure drops (dP _ref )) in the range of 2.875 mm-3.711 mm.

6 is a graph showing the relationship between the tube hydraulic diameter D _t , the heat dissipation performance, and the refrigerant pressure drop in the evaporator using the HFO 1234yf refrigerant. As the tube hydraulic diameter D _t changes, the heat radiation performance Q and the refrigerant pressure drop dP _ref vary greatly as shown in FIG. 6, but the air pressure drop dP _air does not change significantly. Did not do it.

FIG. 6 (A) shows a range in which the heat dissipation performance Q is 99% or more and the refrigerant pressure drop dP _ref is 90% or less as compared with an evaporator using the R-134a refrigerant. . As shown, the upper limit of the tube hydraulic diameter D _t is determined to be 1.775 mm by the heat dissipation performance (Q) constraint, and the lower limit of the tube hydraulic diameter D _t is 0.946 mm by the refrigerant pressure drop (dP _ref ) constraint. Is determined.

In FIG. 6B, the heat dissipation performance Q is 98% or more and the refrigerant pressure drop dP _ref is 95% or less as compared with an evaporator using a R-134a refrigerant. . , The heat radiation performance (Q) by the constraint tube upper limit value of the hydraulic diameter D _t is decided to 1.839mm, the refrigerant-side pressure drop (dP _ref) tube hydraulic diameter D _t by the constraint, as illustrated, the lower limit value is set to 0.780 Determined in mm.

That is, it is preferable that the tube hydraulic diameter D _t of the evaporator using the 1234yf refrigerant has a value within the range of 0.780 mm to 1.839 mm (heat dissipation performance (Q) of 98% or more, and refrigerant pressure drop (dP _ref ) of 95% or less). It is more preferable to have a value (99% or more of heat radiation performance Q and 90% or less of refrigerant | coolant side pressure drops (dP _ref )) in the range of 0.946 mm-1.775 mm.

7 is a graph illustrating a relationship between FPDM, heat dissipation performance, and air pressure drop in an evaporator using HFO 1234yf refrigerant. As the FPDM changes, the heat radiation performance Q and the air pressure drop dP _air vary greatly as shown in FIG. 7, but the coolant pressure drop dP _ref is not shown.

In Fig. 7A, the heat dissipation performance Q is 99% or more, and the air pressure drop dP _air is equal to, or 100% or less, compared with the evaporator using the R-134a refrigerant. It is shown. As shown, the upper limit of the FPDM is determined to be 88.897 by the _air pressure drop (dP _air ) constraint condition, and the lower limit of the FPDM is determined to be 65.190 by the heat dissipation performance (Q) constraint.

In FIG. 7B, the heat dissipation performance Q is 98% or more and the air pressure drop dP _air is equivalent to that of the evaporator using the R-134a refrigerant. It is shown. As shown, the upper limit of the FPDM is determined to be 88.897 by the _air pressure drop (dP _air ) restriction condition, and the lower limit of the FPDM is determined to be 63.439 by the heat radiation performance (Q) restriction condition.

That is, the FPDM of the evaporator using the 1234yf refrigerant preferably has a value within the range of 63.439 to 88.897 (heat dissipation performance (Q) of 98% or more, air side pressure drop (dP _air ) of 100% or less), and is within the range of 65.190 to 88.897. It is more preferable to have a value (99% or more of heat radiation performance (Q) and 100% or less of _air pressure drop (dP _air )).

In summary, the numerical range of each design variable of the evaporator using the 1234yf refrigerant is preferably determined as shown in Table 1 below.

-More than 98% of heat dissipation performance-Less than 95% of pressure drop in refrigerant (dP _ref )-Less than 100% of pressure drop in _air (dP _air ) -More than 99% of heat dissipation performance-Less than 90% of pressure drop on refrigerant (dP _ref )-Less than 100% of pressure drop on _air (dP _air ) Tube height (H _t , mm) 2.489-4.082 2.875-3.711 Tube Hydraulic Diameter (D _t , mm) 0.780 ~ 1.839 0.946-1.775 FPDM 63.439 ~ 88.897 65.190-88.897

The present invention is not limited to the above-described embodiments, and the scope of application of the present invention is not limited to those of ordinary skill in the art to which the present invention pertains without departing from the gist of the present invention as claimed in the claims. Of course, various modifications can be made.

1 is a p-h diagram of a R-134a refrigerant and a HFO 1234yf material refrigerant.

2 is a form of a four pass tube-pin type evaporator.

3 shows an example of refrigerant flow in a tube-pin type evaporator.

4 is a detailed shape of each of the evaporator.

5 is a graph of the relationship between the tube height Ht and the heat radiation performance and the refrigerant pressure drop.

6 is a graph of the relationship between the tube hydraulic diameter Dt and the heat radiation performance and the refrigerant pressure drop.

7 is a graph of the relationship between the FPDM and the heat radiation performance and air pressure drop.

8A is a graph illustrating a relationship between a single part heat dissipation performance and an air conditioning system performance (discharge air temperature) according to various types of cores;

8B is a graph illustrating a relationship between single component refrigerant pressure drop and air conditioner system performance (discharge air temperature) according to various types of cores;

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

100: evaporator 10: header tank

20: Tube 30: Pin

Claims (7)

compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10, The heat exchange medium is a refrigerant comprising a HFO 1234yf material, Tube height H _t has a value within the range of 2.489 mm to 4.082 mm, the flow of the heat exchange medium is a tube-fin type evaporator 100 consisting of four passes; Vehicle air conditioning system using a four-pass tube-pin type evaporator using the refrigerant HFO 1234yf material refrigerant, characterized in that consisting of a refrigerant circuit comprising a. The method of claim 1, wherein the tube height H _t is A vehicle air conditioning system using a four-pass tube-pin type evaporator using HFO 1234yf material refrigerant, characterized by a value in the range of 2.875 mm to 3.711 mm. compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10, The heat exchange medium is a refrigerant comprising a HFO 1234yf material, Tube hydraulic diameter D _t has a value within the range of 0.780 mm to 1.839 mm, the flow of the heat exchange medium is a tube-fin type evaporator 100 consisting of four passes; Vehicle air conditioning system using a four-pass tube-pin type evaporator using the refrigerant HFO 1234yf material refrigerant, characterized in that consisting of a refrigerant circuit comprising a. The tube hydraulic diameter D _t is A vehicle air conditioning system using a four-pass tube-pin type evaporator using HFO 1234yf material refrigerant, characterized in that it has a value in the range of 0.946 mm to 1.775 mm. compressor; Condenser; Expansion valves; And a plurality of tubes 20 arranged in parallel at regular intervals in parallel to the air blowing direction, and fins 30 increasing the heat transfer area with air interposed between the tubes 20 and flowing between the tubes 20. And a pair of header tanks 10 coupled to both ends of the tube 20 through which a heat exchange medium flows, and at least one baffle 40 provided in the header tanks 10, The heat exchange medium is a refrigerant comprising a HFO 1234yf material, Acid or bone number FPDM of fins per decimeter has a value in the range of 63.439 to 88.897, the flow of the heat exchange medium is a four-pass tube-pin type evaporator (100); Vehicle air conditioning system using a four-pass tube-pin type evaporator using the refrigerant HFO 1234yf material refrigerant, characterized in that consisting of a refrigerant circuit comprising a. The method of claim 5, wherein the FPDM A vehicle air conditioning system using a four-pass tube-pin type evaporator using HFO 1234yf material refrigerant, characterized in that it has a value in the range of 65.190 to 88.897. The evaporator 100 according to any one of claims 1 to 6, wherein the evaporator 100 The first tube group (①-4) to the fourth tube group (④-4) is formed with the baffles provided in the upper and lower tanks of the first row and the second row, and the heat exchange medium is the first tube group ( A vehicle air conditioning system using a four-pass tube-pin type evaporator using HFO 1234yf material refrigerant, characterized in that it passes sequentially through (1-4) to the fourth tube group (4-4).

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