JPS60200089A - Direct expansion type regenerative heat exchanger - Google Patents

Abstract

PURPOSE:To secure the velocity of freezer oil to return to a compressor and to decrease head loss as well, by constituting a heat exchanger pipe in such a manner that the number of pipes is increased or the diameter of a pipe is increased, in proportion to the drying degree of a cooling medium. CONSTITUTION:A heat exchanging pipe 13 to pass through a cooling medium is provided in a storage tank 11 in which a liquid 12 is stored. The heat exchanging pipe 13 is constituted in such a manner that the number of pipes is increased in proportion to the drying degree of a cooling medium, that is, an inlet 13a, where the drying degree of a cooling medium is small, is constituted by one pipe only, and the number of pipes is increased from two to three in accordance with the increase of drying degree, and the medium is discharged from an outlet 13b. In such a manner, the number of heat exchanger pipes 13 is increased in proportion to the ratio of capacity of cooling medium flowing through the heat exchanger pipes 13. With such an arrangement, the minimum velocity of freezer oil to return to a compressor is secured without fail, and head loss is decreased as well.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a direct expansion type heat exchanger for thermal storage, and more specifically, a heat exchange pipe through which a refrigerant flows is arranged in a heat storage tank, and the water in the heat storage tank is This invention relates to a heat storage heat exchanger that stores heat in a liquid by exchanging heat between the liquid and a refrigerant.

[Background of the invention]

The conventional direct expansion type heat storage heat exchanger, as shown in Fig. 1,
A compressor that compresses the refrigerant is installed inside a heat storage tank 1 that stores a liquid 2 such as water, and the heat exchange pipe 3 through which the refrigerant flows consists of pipes with the same diameter from the inlet 3a to the outlet 3b. Since a small amount of refrigerant oil is contained in the refrigerant and sent out from the refrigerant for lubricating the inside of the compressor, it is necessary to circulate this refrigerant oil together with the refrigerant through the refrigeration cycle and return it to the compressor. For this purpose, it is necessary to maintain the flow rate of the refrigerant flowing through the heat exchange tube 3 above a certain level.
Since the pipes have the same diameter from the inlet 3a to the outlet 2b, the heat loss inside the heat storage tank 1 becomes large. In addition, in this heat exchanger, ice is applied to the outer periphery of the heat exchange tube 3 in summer, so if you want to use it for good heat exchange without increasing the thickness of the ice, the heat exchange tube 3 The length of the heat exchanger must be made considerably longer, and the entire heat exchanger becomes larger, resulting in an even larger radial loss. Therefore, in the conventional heat storage heat exchanger, there is a problem in that the suction pressure of the compressor is lower than the evaporation pressure, and the compressor must be operated at a low efficiency.

[Purpose of the invention]

An object of the present invention is to provide a direct expansion type heat storage heat exchanger that can secure a flow rate for returning refrigerating machine oil, reduce head loss, and operate the compressor at a point where the efficiency is high. .

[Summary of the invention]

The present invention is characterized in that the specific volume of the refrigerant flowing through the heat exchange tube is small in the dry part on the inlet side, but as it exchanges heat with the liquid in the heat storage tank and becomes dry, the specific volume increases. By focusing on heat exchange tubes, we configured heat exchange tubes with a type in which the number of pipes increases or the pipe diameter increases in proportion to the degree of dryness of the refrigerant, and at the same time, secures a refrigerant flow rate that can return refrigeration oil. This is designed to reduce head loss.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to FIG. Second
The figure shows a sectional view of a direct expansion type heat storage heat exchanger according to the present invention, where 11 is a heat storage tank that stores a liquid 12 such as water, and 13 is a heat storage tank that stores a liquid such as water. With exchange tube
The heat exchange tubes 13 have a shape in which the number of pipes increases in proportion to the degree of dryness of the refrigerant. To explain in detail, the inlet +3a side where the degree of dryness of the refrigerant is small is not connected to one pipe, the part where the degree of refrigerant is a little dry is not connected to two pipes, and the side where the degree of refrigerant is the highest is the outlet +3b side. consists of three pipes.

In the heat exchanger for heat storage according to the present invention, the number of pipes in the heat exchange tube 13 increases in proportion to the increase in the specific volume of the refrigerant flowing through the heat exchange tube 13, so that the refrigerating machine oil is returned to the compressor. The minimum flow velocity for this purpose is ensured, and head loss is reduced.

Therefore, the difference between the evaporation pressure and the compressor suction pressure can be reduced, and the compressor can be operated at a more efficient point.

FIG. 3 shows another embodiment of the present invention, and the difference from FIG. 2 is that the heat exchange tube is a heat exchange tube whose diameter increases in proportion to the degree of dryness of the refrigerant. 13'.

In this embodiment as well, the same functions and effects as those in FIG. 2 can be achieved.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to ensure the flow velocity for returning the refrigerating machine oil and at the same time reduce head loss, so that the compressor can be operated at a point where the efficiency is higher.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional direct expansion heat exchanger for heat storage, FIG. 2 is a sectional view showing an embodiment of the direct expansion heat exchanger of the present invention, and FIG. 3 is a sectional view showing an embodiment of the direct expansion heat exchanger for heat storage of the present invention. FIG. 7 is a sectional view showing another embodiment. 11... Heat storage tank 12... Liquid 13.13'...
・Heat exchange tube. Representative patent attorney Akihiro Takahashi

Claims (1)

[Claims] In a direct expansion heat storage heat exchanger that stores heat in a liquid by disposing a heat exchange pipe through which a refrigerant flows in a heat storage tank and exchanging heat between the liquid in the heat storage tank and the refrigerant, the heat exchanger A direct expansion type heat storage heat exchanger, characterized in that the tubes are configured with heat exchange tubes in which the number of pipes or the diameter of the pipes increases in proportion to the degree of dryness of the refrigerant.