JPS5841A - Heat exchanger utilizing pipe heater - Google Patents

Abstract

PURPOSE:To prevent after-boiling, as well as to prevent a trouble occurring during heat exchanging, by interconnecting the suction port of an ejector, provided to the top part of a heater, to the outlet of a heater, by an interconnecting pipe with a liquid reservoir, in a heat exchanger to supply hot water, using a pipe heater of inside and outside piping type. CONSTITUTION:A fluid is fed into a heat exchanger from a pipe 17 by opening of a valv 19, and a heater 4 is charged with electricity by the closing of a flow switch 18. The fluid is jetted into a flow path 20 through an inlet 8, a flow path 9, and a jet nozzle 12, and flowing out from an outlet 16, with the lowering of the pressure at a suction port 13. At this time, the fluid flows to an outlet 16, a liquid reservoir 15, and a suction port 13 by the function of an ejector 11, while the flow rate of a flow path 12 is increased, so that the heat exchanging rate is also increased. The flow of fluid is stopped by closing a valve 19. The temperature of fluid is increased by the heating capacity of a heater 1, when a switch 18 is opened, but the fluid in a flow path 9 can radiate heat from an outer tube 7, and the fluid in a flow path 20 is naturally convected through the suction part 13, the liquid reservoir 15, and the outlet 16, so that the over- rising temperature in the fluid can be prevented.

Description

[Detailed description of the invention] The present invention is a hot water supply using a hollow pipe heater.

The present invention relates to a heat exchanger in a device that heats a liquid, such as a space heater.

The hollow tube pipe heater in such a heat exchanger has the great advantage of being able to obtain a large heat exchange area with a small volume when exchanging heat with the liquid. The drawback is that the temperature of the liquid accumulated inside cannot be prevented from rising rapidly due to the heat capacity of the heater. In other words, since the liquid is inside the hollow seal, almost no heat can be dissipated, and the temperature of the liquid increases accordingly.

As mentioned above, if the temperature of the liquid rises rapidly, the high-temperature liquid will be ejected when the system is stopped and used again, so there is a risk of burns if the system is used as a heat exchanger for water, such as in a water heater.

The present invention has a configuration in which the liquid flows in from the outer wall side of the heater and flows out through the inner wall, an ejector is provided at the top of the heater, and a communication pipe is provided that communicates the suction port of the ejector with the outlet of the heater. To provide a heat exchanger using a hollow heater which prevents after-boiling with a simple structure without impeding heat exchange of the heater by providing a liquid reservoir part in the middle of the communication pipe.

An embodiment of the present invention will now be described in detail.

FIG. 1 is a diagram showing an example of a pipe heater.

The pipe heater 1 has an outer wall 2 and an inner wall 3, and the inner wall 3 is a hollow penetrating pipe. The heater 4 is embedded between the outer wall 2 and the inner wall 3. A flange 5 necessary for the construction is integrally attached to a suitable part of the knobbic heater 1.

FIG. 2 shows a cross-sectional view of a heat exchanger using the pipe heater 1. On the outside of the pipe heater 1, an outer cylinder 7 sealed by an O-ring 6 of the flange 5 is attached to the flange 5. A liquid inlet 8 is provided in the outer cylinder 7 near the flange 5, and a first flow path 9 is formed between the liquid inlet 8 and the outer wall 2 of the tube heater 1. An ejector 11 is formed in a top portion 10 of the pipe heater 1, with the inner wall 3 serving as a guide wall.

This ejector 11 is formed by a jet nozzle 12 and a suction port 13 located at its center. The suction port 13 is connected to a communication pipe 14, and in the middle of the communication pipe 14,
A liquid volume of 9 parts 15 is provided. The other end of the communication pipe 14 is communicated with the outlet 16 of the nob heater 1 . The operation of the above configuration will be described below.

A pipe 17 for supplying liquid is connected to the liquid inlet 8 via a flow switch 18, and the outlet 16 is provided with a valve 19 for opening and closing the flow of the liquid. The flow switch 18 is wired so that it is energized when there is a liquid flow in the heater 4, and is not energized when there is no flow. Now, when the valve 19 is opened, liquid is supplied from the pipe 17, the flow switch 18 is closed, and the heater 4 is energized. The liquid flows through the first channel 9 from the liquid inlet 8 and is ejected from the jet nozzle 12 into the second channel 2Q formed by the inner wall 3.

At this time, due to the configuration of the ejector 11, the flow of the jet nozzle 12 causes the jet nozzle 1 to enter the suction port 13.
A pressure lower than that of 2 is generated. The flow that has entered the second flow path 2o flows out from the outlet 16 via the valve 19 while causing a pressure drop. Since the liquid is heated by the heater 4, the liquid heater 1 reaches a high temperature and applies heat to the liquid through the inner wall 3 and outer wall 2 to raise the temperature and cause the liquid to flow out from the valve 19. At this time, the flow of the communication pipe 14 is
Since the pressure at the suction port 13 is lowered by the zero action, the liquid is pulled from the outlet 16 and a liquid flow is created from the outlet 16 to the suction port 13 via the liquid measuring section 15.

Therefore, the flow of liquid passing through the second flow path 20 is
This increases the apparent amount of liquid flowing in from 7, and the heat exchange between the inner wall 3 and the fluid increases by the amount of liquid that increases.

Next, when the valve 19 is closed, the liquid no longer flows in from the pipe 17, the flow switch 18 is opened, and the power supply to the heater 4 is stopped. At this time, the liquid in the first flow path 9 and the second flow path 20 is heated by the heat capacity of the pipe heater 1.

Even if the liquid in the first channel 9 is heated in a stationary state, heat is radiated from the outer cylinder 7 by thermal convection, and an excessive temperature rise is prevented. In the second flow path 20, the heated liquid has a lower density and rises, enters the communication pipe 14 from the suction port 13, and flows through the liquid measuring section 15 to the communication pipe 14 and the outlet 16 through natural convection. Occur. Due to this natural convection, the liquid in the liquid metering section 16 flows in from the outlet 16, thereby preventing the liquid in the second flow path 2o from rising excessively in temperature. The above operation prevents an excessive rise in liquid temperature due to the heat capacity of pipe heater 1, which occurs when the flow of liquid is stopped. Now, if only the communication pipe 14 is installed without the ejector 11, there will be no pressure drop in the ejector 11, so the flow in the first flow path 9 will be
The flow is distributed between the second flow path 20 and the communication pipe 14, and the communication pipe 1
The amount of liquid in the second flow path 20 is reduced by the amount of liquid flowing into the second flow path 20,
The amount of heat exchanged between the inner wall 3 and the liquid decreases, causing an abnormal temperature rise in the pipe heater 1. This is because the amount of heat from the pipe heater 1 cannot be effectively transferred to the liquid. On the other hand, when the ejector 11 is provided, the amount of liquid in the second flow path 20 increases, and effective heat exchange can be performed. Therefore, even if the communication pipe 14 is provided, it will not impede the heat exchange of the pipe heater 1, and the communication pipe 14 can sufficiently fulfill its role even when the liquid flow is stopped.

The present invention can minimize the rise in liquid temperature when the flow of liquid in the inner tube of the pipe heater is stopped, so no abnormal temperature rise occurs and liquid at an appropriate temperature is always supplied. )-A: ET table p, L-s, b, V, Niji, Kutano role space 11≠; Works as a system to efficiently exchange heat between the heater and the liquid when there is a liquid flow. In addition, the ejector itself has a simple configuration, so it does not become a complicated system.
This effectively utilizes natural convection when the liquid flow is stopped to minimize the temperature rise of the liquid.

[Brief explanation of the drawing]

FIG. 1 is an external view of a pipe heater in an embodiment of the heat exchanger of the present invention, and FIG. 2 is a sectional view of the same heat exchanger. 1... Vibe heater, 2... Outer wall, 3
...Inner wall, 4...Heater, 1o...
...Top of head, 11...Ejector, 13.
...Suction port, 14...Communication pipe, 15...
...Liquid reservoir, 16...Exit. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure

Claims (1)

[Claims] In a heat exchanger using a heater that exchanges heat with a liquid through cylindrical outer and inner walls, the liquid is made to flow in from the outer wall of the heater and flow out through the inner wall, and the top of the heater is A heat exchanger using a pipe heater, characterized in that an ejector is provided, a suction port of the ejector communicates with an outlet of the heater, and a liquid reservoir is provided in the middle of the communication pipe.