JPH0345892A - Separate type heat exchanger - Google Patents

Abstract

PURPOSE:To largely improve thermal exchanging performance and to reduce its cost by directing refrigerant flow at the time of operation as a condenser from a heat exchanger of a downstream side toward a heat exchanger of an upstream side, forming a heat transfer tube of the exchanger of the downstream side with inner grooves, and forming a heat transfer tube of the exchanger of the upstream side as an inner smooth tube. CONSTITUTION:High temperature and high pressure refrigerant gas is introduced from a refrigerant inlet tube 1 into a heat transfer tube 6 with inner grooves of a heat exchanger 4 of a downstream side, heat is radiated through fins 7 so that the gas is condensed, the refrigerant is liquefied while moving from the exchanger 4 to a heat exchanger 3 of an upstream side, and its supercooling degree is accelerated toward a refrigerant outlet tube 2 in an inner smooth heat transfer tube 5 of the exchanger 3. Here, since the fins 7 are separated from the exchangers 4, 3, thermal conduction through the fins 7 is substantially thermally insulated, supercooled refrigerant in the tube 5 near the tube 2 of the exchanger 3 is not substantially affected by the thermal influence of the high temperature refrigerant of the tube 6 with the inner grooves near the tube 1, and the supercooling degree can be sufficiently provided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an air/refrigerant heat exchanger used for space heating.

Conventional technology Conventionally, in order to improve the performance of this type of indoor heat exchanger for heating, the shape of the fins was modified to improve the heat transfer coefficient on the air side. In order to improve heat transfer efficiency, heat transfer tubes, which serve as refrigerant passages, are grooved on the inside to improve heat transfer efficiency, and heat exchange efficiency is improved by connecting grooves in heat transfer tubes so that the flow of refrigerant is in the opposite direction to the flow of air. There is something to do.

Problems to be Solved by the Invention However, in order to further improve the performance of an indoor heat exchanger for heating, it is necessary to increase the degree of supercooling of the liquid refrigerant flowing out from the heat exchanger as a condenser. There is a problem in that a sufficient degree of supercooling cannot be achieved due to heat conduction from the high temperature heat transfer tube on the inflow side to the heat transfer tube on the outflow side through the fins. In addition, adopting internally grooved tubes to improve the heat transfer coefficient of heat transfer tubes increases costs, and increases the flow resistance on the refrigerant side, which increases the energy cost required for heat transfer. be.

The present invention solves such conventional problems, and aims to sufficiently improve the degree of subcooling of a heat exchanger as an AIL device, improve performance, and suppress increases in material costs and running costs.

Means for Solving the Problems In order to solve the above problems, the separate heat exchanger of the present invention has the following features:
The fin-tube heat exchangers are arranged separately on the windward side and the leeward side, and the refrigerant flow when acting as an a-detector flows from the leeward side heat exchanger to the windward side heat exchanger. The heat exchanger tubes of the heat exchanger are grooved tubes on the inside, and the heat exchanger tubes of the windward side heat exchanger are smooth tubes on the inside.

Function The present invention has the above-described configuration, so that when it acts as a condenser, the liquid refrigerant part is located on the windward side, so it exchanges heat with the inflowing air before temperature rise, and the part on the leeward side through which the high temperature refrigerant passes. Since the fins are separated and thermally insulated, the degree of supercooling can be increased and heat exchange performance is greatly improved. In addition, the heat exchanger tubes in the leeward side heat exchanger are grooved tubes on the inside, which contributes to improving the heat transfer coefficient especially in the two-phase region of the refrigerant. Even if a grooved tube is used, the effect on improving the heat transfer coefficient is small, and the flow path resistance increases. Therefore, by using a tube with a smooth inner surface, it is possible to reduce the material cost and the energy cost required for heat transfer.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings.

In Figures 1 and 2, ■ is the refrigerant inlet pipe of the heat exchanger that acts as a condenser, 2 is the refrigerant outlet pipe, 3 is the windward heat exchanger, 4 is the leeward heat exchanger, and 5 is the calm. 6 is a heat exchanger tube with a smooth inner surface of the upper heat exchanger, 6 is a heat exchanger tube with an inner groove of the leeward heat exchanger, and 7 is a fin arranged in parallel at regular intervals perpendicular to each heat exchanger tube 5, 6. . The windward heat exchanger 3 and the leeward heat exchanger 4 are arranged with separate fins 7, so that the refrigerant flow when acting as a condenser is from the leeward heat exchanger 4 to the windward heat exchanger 3. The heat exchanger tubes are connected so as to flow, and the windward side heat exchanger 3 is connected to the heat exchanger tube 5 with a smooth inner surface.
The leeward heat exchanger 4 is a heat exchanger tube with internal grooves.

In the above configuration, when acting as a condenser, high temperature and high pressure refrigerant gas is passed from the refrigerant inlet pipe 1 to the leeward heat exchanger 4.
The refrigerant enters the inner grooved heat exchanger tube 6, radiates heat through the fins 7, and condenses.The refrigerant progresses to liquefy as it moves from the leeward heat exchanger 4 to the windward heat exchanger 3, and the refrigerant liquefies the inner surface of the windward heat exchanger 3. In the smooth heat exchanger tube 5, the degree of supercooling is accelerated as it approaches the refrigerant outlet pipe 2. Here, since the fins 7 of the leeward side heat exchanger 4 and the windward side heat exchanger 3 are separated, heat conduction through the fins 7 is almost thermally insulated from each other.
The supercooled refrigerant liquid in the smooth inner surface heat transfer tube 5 near the refrigerant outlet pipe 2 of the windward heat exchanger 3 is affected by the heat of the high temperature refrigerant in the inner grooved heat transfer tube 6 near the refrigerant inlet pipe 1 of the leeward heat exchanger 4. This results in a sufficient degree of supercooling.

In addition, the leeward side heat exchanger 4 has a heat exchanger tube with an inner grooved heat exchanger tube 6.
This increases the effect of improving the heat transfer coefficient, especially in the process of condensation and liquefaction in the two-phase region of the refrigerant. Since the effect on improving the heat transfer coefficient is small and the flow path resistance is increased, the heat exchanger tube 5 with a smooth inner surface can reduce the material cost and the energy cost required for heat transfer.

Effects of the Invention As described above, the separate heat exchanger of the present invention provides the following effects.

The fin-tube heat exchangers are arranged separately on the windward side and the leeward side, and the refrigerant flow when acting as a condenser flows from the leeward side heat exchanger to the windward side heat exchanger. The heat exchanger tubes in the heat exchanger are grooved tubes on the inside, and the heat exchanger tubes in the upwind side heat exchanger are smooth tubes on the inside, so the liquid refrigerant part when acting as a condenser is on the windward side, so it flows in. Because it exchanges heat with the air before temperature rise, and because it is thermally insulated from the part on the leeward side through which high-temperature refrigerant passes and is not affected by heat conduction, a large degree of supercooling can be obtained, and heat exchange performance is improved. Significantly improved. Furthermore, since the heat exchanger tubes of the windward side heat exchanger have smooth inner surfaces, the material cost can be reduced, and since the flow path resistance is reduced, the energy cost required for heat transfer can also be reduced.

[Brief explanation of drawings]

FIG. 1 shows a refrigerant flow path structure t2. of a separate heat exchanger in an embodiment of the present invention. 2 are cross-sectional configuration diagrams of the separation type heat exchanger. 1... Refrigerant artificial piping, 2... Refrigerant outlet piping, 3... Windward side heat exchanger, 4...
Downward side heat exchanger, 5...Smooth inner surface heat exchanger tube, 6.
... Heat exchanger tube with internal groove, 7 ... Fin.

Claims (1)

[Claims] A heat exchanger consisting of a group of fins arranged in parallel at regular intervals and a group of heat transfer tubes that are perpendicular to the fin groups and through which a refrigerant flows are arranged on the windward side and the leeward side with respect to the airflow to exchange heat, The refrigerant flow when acting as a condenser is configured to flow from the leeward heat exchanger to the windward heat exchanger, and the heat exchanger tube group of the leeward heat exchanger is a tube with internal grooves. The heat tube group is a separate heat exchanger with smooth inner surfaces.