JP2000205787A - Water heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heat exchanger capable of preventing water from being frozen in a shell. SOLUTION: In a shell 23 where left and right opposite ends are closed with a tube plate 35, and there are disposed in parallel a refrigerant supply tube 7 and a same return tube 11 directed left and right therein there are alternately provided an upward baffle 25A having a communication section 25a on an upper portion and a downward baffle plate 25B having a communication section 25b on a lower portion. Further, there are provided a water inlet tube 21 and an outlet tube 27 left and right on a lower portion of the shell 23, and there is further provided a water communication through-hole 43 in a lower portion of the upward buffle plate 25A located upstream a refrigerant at least in the refrigerant forward tube in the baffle plates.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for exchanging heat between a refrigerant and water, and more particularly to a chiller water heat exchanger.

[0002]

2. Description of the Related Art An example of a conventional water heat exchanger is shown in FIGS. The refrigerant 1 enters the inflow chamber 5 through the refrigerant inlet pipe 3, flows into the return chamber 9 through the plurality of refrigerant outgoing pipes 7 in the shell 23, and returns through the refrigerant return pipe 11 to the outflow chamber. The refrigerant flows out of the refrigerant outlet pipe 15 through the outlet 13.

On the other hand, water 19 is supplied from a water inlet pipe 21 to a shell 2.
3, flows through a zigzag water channel formed by the plurality of baffle plates 25, flows out of the water outlet pipe 27, and exchanges heat with the refrigerant 1 while the water 19 flows zigzag. .

In the conventional water heat exchanger, as shown in FIG. 5, a water inlet pipe 21 and a water outlet pipe 27 are provided horizontally on the side of the shell 23, and water is fed into the shell from the side.

In the above-described conventional water heat exchanger, a stagnant area 29 where the flow of water stagnates and vortices are likely to be formed downstream of the base of the baffle plate 25 and near the communicating part of the water inlet pipe 21.
Exists on the upstream side of the refrigerant forward pipe 7 through which the low-temperature refrigerant passes, in the stagnation region 29, the water in the stagnation region 29 is excessively cooled and easily frozen, and when the frozen ice grows, the water heat exchanger Function is reduced.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a water heat exchanger capable of preventing freezing of water inside a shell.

[0007]

In order to achieve the above-mentioned object, a water heat exchanger according to the present invention has left and right ends closed by tube sheets, and has therein a refrigerant forward pipe and a return pipe formed in the left and right direction. Are provided side by side in a shell in which an upward baffle plate having a communicating portion at an upper portion and a downward baffle plate having a communicating portion at a lower portion are alternately provided in the left-right direction in the shell, and water inlet pipes are provided on the left and right of the lower portion of the shell. And the same outlet pipe, and a through hole for water circulation is provided at least in the lower part of the upward baffle plate located on the upstream side of the refrigerant in the refrigerant outgoing pipe in the baffle plate.

[0008]

FIG. 1 shows an embodiment of a water heat exchanger according to the present invention.
Description will be made based on specific examples shown in FIGS. As shown in FIGS. 1 and 2, the water heat exchanger of this embodiment has a cylindrical shell 23 whose right and left ends are closed by tube sheets 35, 35, respectively. A number of refrigerant outgoing pipes 7 and refrigerant return pipes 11 are disposed (in the left-right direction)
3 is supported by legs 33.

The left and right tube plates 35, 35 have end plates 3 respectively.
End chambers 37, 9 closed by 7a, 9a are provided, and the inside of the left end chamber 37 is divided into two upper and lower chambers by a partition plate 41, the lower chamber is the inflow chamber 5, and the upper chamber is the outflow chamber 13 The right end chamber 9 is a return chamber.

A coolant inlet pipe 3 communicating with the inflow chamber 5 and a coolant outlet pipe 15 communicating with the outflow chamber 13 are provided in the end plate 37a of the left end chamber. An inlet pipe 21 is provided in the vertical direction, and a water outlet pipe 27 is provided vertically in a lower portion on the right end side.

A plurality of baffle plates are provided inside the shell 23.
Baffle plate 25A having a
b, the upper baffle plate 25A and the lower baffle plate 25B are alternately arranged from the left end to the right end in the figure to form a zigzag water flow path vertically. Each baffle plate 25A, 2
A plurality of refrigerant outward pipes 7 and a refrigerant return pipe 11 penetrate through 5B.

The baffle plates 25A and 25B are supported at their left ends by support rods 12 fixed to a left tube plate 35, and adjacent baffle plates are separated by a predetermined distance by spacer tubes 14 and 14 fitted on the support rods. I keep it. The support rod is, for example, a screw rod, and a nut 16 is provided at the right end.
Is fitted to hold the baffle plate.

However, of the upward baffle plate 25A,
At the most upstream portion of the refrigerant outward pipe 7, that is, at the left end portion in the figure, a through hole 43 for water circulation is provided near the lower wall surface.
Has been opened.

In the water heat exchanger having the above configuration,
The refrigerant sent from the refrigerant inlet pipe 3 to the refrigerant outgoing pipe 7 through the inflow chamber 5 exchanges heat with the water 19 in the shell 23, enters the upper refrigerant return pipe 11 from the return chamber 9, and in this refrigerant return pipe. The refrigerant also exchanges heat with water, is sent to the outflow chamber 13, and flows out of the refrigerant outlet pipe 15 to the outside.

On the other hand, water 19 is supplied from water inlet pipe 21 to shell 2.
3 into the upper part from below, and a plurality of communication parts 25a, 2
Baffle plates 25A, 5b are alternately turned upside down.
5B, and flows in a zigzag manner in the vertical direction to generate a turbulent flow, so that the heat exchange with the refrigerant passing through the refrigerant forward pipe 7 and the refrigerant return pipe 11 is sufficiently performed.

A part of the water sent into the shell is formed in a through hole 4 formed in the base of the upward baffle plate 25A at the left end in the figure.
3, water does not stay around the base of the baffle plate 25A.

When R407C having an evaporation temperature of 0 to -18 ° C. is used as the refrigerant and the inlet temperature of water is 13 to 5 ° C. and the outlet temperature is 7 to 2 ° C., the evaporation temperature of the refrigerant is determined by heat exchange with water. , Immediately evaporates into steam, and further heat exchange increases the temperature to superheated steam.

Therefore, by connecting the water inlet pipe 21 directly below the shell 23, a water stagnation area near the upper wall surface of the tube sheet 35 is formed above the inside of the shell 23, which is the back side of the water inlet pipe 21. However, the refrigerant return pipe 11 in this stagnation area
Most of the refrigerant passing therethrough is heated superheated steam, so that there is almost no risk of water freezing.

Further, although the low temperature from the inflow chamber 5 passes through the refrigerant outgoing pipe 7, the most upstream side of the refrigerant outgoing pipe 7 is still cooled just after flowing into the shell from the water inlet pipe 21. Since relatively hot water flows, there is little risk of freezing.

Further, since the through hole 43 is formed in the baffle plate 25A on the most upstream side, no stagnation area is formed below the baffle plate 25A, and there is no possibility of freezing.

Therefore, even when a refrigerant having a large temperature gradient such as a refrigerant of the R407 series is used, freezing of water in the shell is prevented.

In the above-described embodiment, the through hole 43 formed in the baffle plate is provided with the upward baffle plate 2 on the most upstream side.
Although it is formed only at the lower part of 5A, it may be formed on another upward baffle plate 25A.

Further, instead of providing the return chamber 9 at the end of the shell 23, the return chamber 9 may be omitted by connecting the refrigerant forward pipe 7 and the refrigerant return pipe 11 with a bend pipe or a header. Furthermore, although the case where R407C is used as the refrigerant has been described, other refrigerants can be used.

[0024]

As described above, according to the present invention,
By communicating the water inlet pipe to the lower part of the shell, it is possible to send relatively high-temperature water that has not yet been cooled to the most upstream part of the refrigerant outward pipe, that is, to the part where the coldest refrigerant passes, In addition, it is possible to make it difficult for a water stagnation area to be generated in that portion, and thus it is possible to prevent water from freezing.

A through hole is formed at a lower portion of an upward baffle plate protruding upward from a lower wall surface inside the shell, which is located at least on the most upstream side of the refrigerant flowing through the refrigerant outgoing pipe, that is, at the lowest temperature portion. Since it is open, it is possible to eliminate water stagnation at the base on the back side of the baffle plate,
Therefore, freezing of water at the base of the baffle plate can be prevented.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an embodiment of a water heat exchanger according to the present invention.

FIG. 2 is a partially broken plan view of the water heat exchanger.

3A is a left side view of FIG. 1, FIG. 3B is a longitudinal sectional view taken along line BB, FIG. 3C is a longitudinal sectional view taken along line CC, and FIG.
-D line longitudinal sectional view.

FIG. 4 is an enlarged longitudinal front view showing a support structure of a baffle plate.

FIG. 5 is a front view showing a part of a conventional water heat exchanger in a cutaway manner.

FIG. 6 is a left side view of the water heat exchanger.

[Explanation of symbols]

 Reference Signs List 3 refrigerant inlet 5 inflow chamber 7 refrigerant outgoing pipe 9 return chamber 11 refrigerant return pipe 13 outflow chamber 15 refrigerant outlet 21 water inlet pipe 23 shell 25A upward baffle plate 25B downward baffle plate 25a communication part 25b communication part 27 water outlet pipe 29 stagnant area 35 Tube plate 39 End plate 43 Through hole

Claims (1)

[Claims] 1. An upper baffle plate having a communicating portion at an upper part, a lower baffle plate having a communicating part at an upper part, and a lower part at a lower part in a shell in which left and right ends are closed by tube sheets, and a refrigerant outgoing pipe and a return pipe are formed side by side. A downward baffle plate having a communicating part is provided alternately in the left-right direction in the shell, water inlet pipes and outlet pipes are provided on the left and right of the lower part of the shell, and at least upstream of the refrigerant in the refrigerant outgoing pipe in the baffle plate. A water heat exchanger provided with a through hole for water circulation at the bottom of the upward baffle plate located at