Laminated Heat Exchanger

Abstract

An evaporator implemented by a laminated heat exchanger includes a refrigerant inlet header section, a refrigerant outlet header section, and plural inter mediate header sections. A sixth intermediate header section includes a refrigerant channel allowing refrigerant flow in the longitudinal direction thereof and whose downstream end with respect to the refrigerant flow direction is closed, and causes refrigerant to dividedly flow into a plurality of refrigerant flow tube portions. Refrigerant that has flown into the refrigerant inlet header section from a refrigerant inlet flows into the refrigerant outlet header section through the refrigerant flow tube portions and through the intermediate header sections and flows out from a refrigerant outlet. A resistive plate portion within the sixth intermediate header section blocks the refrigerant channel thereof extending in the longitudinal direction thereof. A resistive hole in the resistive plate portion imparts resistance to refrigerant that flows through the refrigerant channel.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is an application filed under 35 U.S.C. § 111(a) claiming the benefit pursuant to 35 U.S.C. § 119(e)(1) of the filing date of Provisional Application No. 60 / 609,831 filed Sep. 15, 2004 pursuant to 35 U.S.C. § 111(b).TECHNICAL FIELD [0002] The present invention relates to a laminated heat exchanger, and more particularly to a laminated heat exchanger used as an evaporator of a vehicle air conditioner, which is a refrigeration cycle on board a vehicle. [0003] Herein and in the appended claims, the upper, lower, left-hand, and right-hand sides of FIGS. 1, 3, and 11 will be referred to as “upper,”“lower,”“left,” and “right,” respectively. The downstream side of flow (represented by arrow X in FIGS. 1 and 11) of air is referred to as the “front,” and the opposite side as the “rear.”BACKGROUND ART [0004] A laminated heat exchanger that is conventionally used widely as an evaporator of a vehicle air conditioner includes a plur...

AI Technical Summary

Benefits of technology

[0027] According to the laminated heat exchanger of par. 1), the resistive portion is provided in at least one of the refrigerant-flow-dividing header sections so as to impart resistance to refrigerant that flows through the refrigerant channel extending in the longitudinal direction of the refrigerant-flow-dividing header section, so that there can be reduced the quantity of refrigerant that flows beyond the resistive portion in the refrigerant-flow-dividing header section. Accordingly, in the case where the laminated heat exchanger is used as an evaporator of a vehicle air conditioner, even when air-velocity distribution becomes nonuniform on the upstream side with respect to the air flow direction, and consequently air velocity drops in a region corresponding to the downstream side of the resistive portion with respect to the refrigerant flow direction in the refrigerant-flow-dividing header section, an extreme drop in the temperature of air that has passed through the region can be prevented. Thus, the temperature distribution of discharged air can be rendered uniform. Further, in the region where air velocity becomes low, freezing of condensed water on the surfaces of refrigerant flow tube portions and fins can be prevented.

[0028] The laminated heat exchanger of par. 2) allows the resistive portion to be formed relatively easily.

[0029] The laminated heat exchanger of par. 3) allows the resistive plate portion having the resistive hole to be provided relatively easily. Also, leakage of refrigerant from the flat, hollow member having the flat plate can be reliably prevented. Further, the metal plates used to form the flat, hollow member having the flat plate can be identical with those used to form other flat, hollow members, so that the manufacturing cost is lowered.

[0030] The laminated heat exchanger according to any one of pars. 4) to 9) can finely control the flow rate of refrigerant flowing through individual regions thereof in accordance with the nonuniform air-velocity distribution on the upstream side with respect to the air flow direction.

[0031] The laminated heat exchanger of par. 10) can reliably reduce the flow rate of refrigerant that flows beyond the resistive portion in the refrigerant-flow-dividing header section.

[0032] The laminated heat exchanger of par. 11) enables uniformly divided flow of refrigerant into the refrigerant flow tube portions connected to a portion of the refrigerant-flow-dividing header section that is located downstream of the resistive plate portion. When the resistive plate portion is provided within the refrigerant-flow-dividing header section, the velocity of refrigerant that has passed through the resistive hole of the resistive plate portion increases. This causes difficulty for refrigerant to flow into the refrigerant flow tube portion located in the vicinity of the resistive plate portion. However, provision of the guide portion facilitates entry of refrigerant into the refrigerant flow tube portion located in the vicinity of the resistive plate portion. As a result, uniformity can be established in terms of divided flow of refrigerant into the refrigerant flow tube portions connected to a portion of the refrigerant-flow-dividing header section that is located downstream of the resistive plate portion.

Problems solved by technology

In this case, a vehicle-air-conditioner evaporator implemented by a laminated heat exchanger featuring uniformly divided flow of refrigerant into all refrigerant flow tube portions may involve a problem in that the temperature distribution of discharged air; i.e., the temperature distribution of air that has passed the evaporator, may become nonuniform along the left-right direction.

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