JPS5849519Y2 - Shell-and-tube heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to a type of heat exchanger having a plurality of heat exchanger tubes between tube sheets.

For example, in a type of heat exchanger having multiple stages of heat transfer tubes between tube sheets on both sides, such as a surface condenser, when there is a change in the flow rate of the fluid flowing in the heat transfer tubes, the flow velocity in the heat transfer tubes changes accordingly.

As the flow rate decreases, heat transfer deteriorates and foreign matter deposits (
(deposits) may cause corrosion.

Also, as the flow velocity increases, erosion corrosion is more likely to occur.

This invention attempts to suppress such flow rate changes as much as possible through simple valve operations, thereby eliminating the drawbacks of conventional devices that cause problems such as reduced heat transfer and corrosion.

The diagram will be explained.

FIG. 1 shows a conventional heat exchanger, in which 1 is a shell-and-tube heat exchanger, 2 is an inlet chamber, 3 is an outlet chamber, 4 is a fluid inlet pipe, and 5 is an outlet pipe.

The fluid enters the inlet chamber 2 through the inlet pipe 4, passes through the heat transfer water tube section 6, enters the outlet chamber 3, and exits through the outlet pipe 5.

In this conventional configuration, when the flow rate changes, the flow velocity also changes accordingly, causing various troubles as described above.

Therefore, it has been considered to use a plurality of heat exchangers 1, 1' as shown in FIG.

An inlet branch pipe 4' is branched from the inlet pipe 4 that enters the heat exchanger 1, and the outlet pipe 5 is taken out from the heat exchanger 1. It merges with the outlet pipe 5.

A valve 7 is provided on the inlet branch pipe 4', and a valve 8 is provided on the outlet pipe 5'.

When the flow rate is low, the valves 7 and 8 are closed and only the heat exchanger 1 is used, and when the flow rate is increased, the valves 7 and 8 are opened and both the heat exchangers 1 and 1' are used in parallel.

However, although this method can suppress changes in flow velocity, it does not avoid the disadvantage that it is uneconomical because the heat exchanger 1' is not used in some cases.

FIG. 3 shows the shell-and-tube heat exchanger 10 of this invention.
The inlet chamber is divided into chambers 12 and 12' by a partition wall 11, and an inlet pipe 14 is introduced into one of the inlet chambers 12, and an inlet branch pipe 14' is branched from the inlet pipe 14.
enters the other inlet side chamber 12'.

An outlet pipe 15 comes out from the outlet side chamber 16, and an outlet branch pipe 15' comes out from the chamber 12' into which the inlet branch pipe was introduced or the inlet branch pipe 14' and merges with the outlet pipe 15.

The inlet branch pipe 14' has a valve 17, the outlet pipe 15 immediately after leaving the chamber 16 has a valve 18, and the outlet branch pipe 15' has a valve 1.
9 are provided respectively.

13 is a heat exchanger tube section.

The heat exchanger of this invention has such a structure, and when the flow rate is large, the valves 17 and 18 are opened, and the valve 19 is kept closed.

Therefore, the fluid enters the inlet side chambers 12 and 12' from the inlet pipe 14 and the inlet branch pipe 14', and enters the heat exchanger tube section 13.
It flows through the outlet side chamber 16 and exits from the outlet pipe 15.

When the flow rate decreases, valves 17 and 18 are closed and valve 19 is opened.

Then, the fluid flows from the inlet pipe 14 to the inlet side chamber 1.
2, flows through the heat transfer tube section, and valve 18 is closed, so
In the chamber 16, the flow is reversed and flows again in the opposite direction through the heat exchanger tube section, returns to the chamber 12', passes through the outlet branch pipe 15', and exits from the outlet pipe 15.

When the flow rate decreases in this way, the flow becomes a two-pass flow, and the flow path area is halved, so even if the flow rate decreases, the flow velocity does not change.

Conversely, if there is a possibility that the flow rate will increase, plan for two passes at first, and when the flow rate increases to a certain level, open valves 17 and 18, close valve 19, and switch to one pass flow. I'll do what I do.

This invention has such a configuration, and is capable of suppressing changes in flow velocity due to changes in flow rate as much as possible with a simple configuration.

Note that the chamber is generally also called an ice chamber when the fluid is a liquid, and is called a chamber when the fluid 1 is a gas.

Liquid gas can also be used in this heat exchanger. Valve 17.1
A three-way valve may be used instead of 9.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a conventional heat exchanger, FIG. 2 is an explanatory diagram of a case where two heat exchangers are used in parallel, and FIG. 3 is an explanatory diagram of the heat exchanger of this invention. Explanation of symbols 1, 1'...Heat exchanger, 2...
... Entrance side chamber, 3... Outlet side chamber, 4... Inlet pipe, 4'... Artificial branch pipe, 5... Outlet pipe, 5'...Outlet branch pipe, 6...Heat transfer tube, 7, 8...Valve,
10...Heat exchanger of this invention, 11...
・Bulkhead, 12.12'...Population side chamber,
13... Heat exchanger tube section, 14... Inlet pipe,
14'...Inlet branch pipe, 15...Outlet pipe, 15'...Outlet branch pipe, 16...
Outlet side chamber, 17, 18. 19... Valve.

Claims (1)

[Scope of utility model registration request] In a type of heat exchanger in which a plurality of heat transfer tubes are provided between tube sheets on both sides, the inlet side chamber is partitioned by a partition wall, an inlet tube and an inlet branch pipe are introduced into each of the divided chambers, and an outlet tube is introduced into the outlet side chamber. Then, take out the outlet branch pipe from the inlet side chamber or the inlet branch pipe where the artificial branch pipe was introduced and merge it with the outlet pipe, and the inlet branch pipe,
A multi-tube heat exchanger characterized in that an outlet pipe and an outlet branch pipe are each provided with a valve.