JPS5924799B2 - Regenerative heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a regenerative heat exchanger that effectively uses fluctuating thermal energy.

BACKGROUND OF THE INVENTION Many thermal energy discharged from industrial equipment, such as garbage incinerators, have an amount of discharged heat and a discharge temperature that fluctuate over time, as shown in FIGS. 1 and 2.

In most cases, such fluctuating thermal energy is not used effectively.

That is, at present, since the steady operation of the device is considered as the first condition, it is used only at the minimum level shown by the broken line in FIGS. 1 and 2.

However, when the temperature level is below 300°C and the fluctuations in the amount of heat discharged are relatively small, a method of absorbing the fluctuations using a type of heat storage device called a steam accumulator is still used.

The present invention proposes a regenerative heat exchanger that mainly utilizes the heat of fusion of inorganic substances, targeting a high temperature range of 300°C or higher, for example. Select a melting substance with a melting point A between .

An embodiment of the present invention will be described below based on the drawings.

In FIG. 3, reference numeral 1 denotes a thermal energy discharge source such as a garbage incinerator, and here it is assumed that high-temperature gas 4 is used as a heat transfer medium.

2 is a device that utilizes thermal energy from the thermal energy exhaust source 1, such as a gas turbine or a steam turbine.

Reference numeral 3 denotes a regenerative heat exchanger that is interposed between the thermal energy exhaust source 1 and the thermal energy utilization device 2, and mainly utilizes the heat of fusion of inorganic substances, so that the temperature of the high-temperature gas 4 reaches the melting point A in Fig. 2.
During the following time periods, excess heat melts the substance, first as heat of fusion, and then excess heat is stored in the melted substance (liquid) as sensible heat.

Next, when the temperature of the high-temperature gas 4 decreases to below the melting point A, the heat storage material releases thermal energy as sensible heat and solidification heat to the heat transfer medium gas 4, causing the gas 4 to become low temperature. To prevent.

Therefore, by designing the regenerative heat exchanger 3 taking into account the balance between heat transfer rate, temperature level, and heat capacity, it is possible to effectively utilize fluctuating thermal energy.

Figure i4 a j b shows a shell-and-tube type regenerative heat exchanger 5, which is separated by a body shell 6 and front and rear partition walls 7, 8, and has a heat exchanger in the middle of the temperature fluctuation range of high-temperature gas. A shell part 10 in which a molten substance 9 having a melting point, such as chloride, is enclosed, and a passage for high temperature gas 11 passing through the shell 10 in the front and back direction, and a passage between the high temperature gas 11 and the molten substance 90. Multiple heat exchanger tubes 1 for heat exchange
2, the shell portion 10 is driven by a motor 15 through a pinion 14 that engages an annular rack 13 fixed to the circumference of the body outer plate 6, and the axis parallel to the tube axis of the heat transfer tube 12 is It is rotated around 16 degrees.

-17 is a sealing portion interposed between the trunk outer plate 6 and the fixed portion outer plate 18.

By rotating the shell part 10 around the axis 16 by the motor 15, the molten substance 9 is stirred, and the heat exchanger tube 1
2 External convective heat transfer is significantly promoted.

As shown in FIG. 4, the shell portion 10 is provided with a baffle plate 19 protruding from the inner surface of the body outer plate 6 to further promote the stirring effect.

In this way, it is possible to remove more than the difference in density between the melted material (liquid) and the unmelted material (solid) in the shell portion 10.

In addition, in consideration of the volume change due to the solid-liquid phase change of the molten substance 9, the volume of the shell portion 10 needs to have an allowance.

When the high-temperature gas 11 with a fluctuation range is supplied, during the time period when the temperature of the high-temperature gas 11 is higher than the melting point of the molten substance 9,
Excess heat is stored as sensible heat in the molten substance 9 while passing through the heat exchanger tube 12 .

Next, during the time period when the temperature of the high-temperature gas 11 decreases to below the melting point, the previously stored thermal energy is conversely released to the gas 11 through the heat transfer tube 12, and the temperature of the discharged gas is approximately close to the melting point. is maintained.

At this time, since the shell portion 10 is rotated around the axis 16, the molten substance 9 is stirred, and convective heat transfer outside the heat transfer tube 12 is significantly promoted.

When a waste incinerator is considered as the thermal energy emission source 1, the temperature of the exhaust gas discharged from the incinerator fluctuates between 500° C. and 1000° C. with a period of about 0.5 to 1 hour.

In such cases, sodium chloride (
By using NaCl (melting point 8004°C), the exhaust gas temperature can be averaged to approximately 800°C.

As described above, according to the present invention, even if the heat transfer medium has a fluctuation range, it can be easily averaged, and the heat transfer medium can be efficiently made into a heat transfer medium with less temperature fluctuation.

Further, since a rotation drive device for rotating the heat exchanger is provided and a baffle plate that projects inward is provided on the body outer plate of the shell portion, convective heat transfer on the outside of the heat exchanger tube can be significantly promoted.

[Brief explanation of drawings]

Figures 1 and 2 are exhaust heat quantity and exhaust temperature characteristic diagrams with fluctuation ranges, Figure 3 is a system diagram in which the present invention is used, and Figures 4 a and b are longitudinal sections showing one embodiment of the present invention. They are a top view and a cross-sectional view. 5...Shell and tube type regenerative heat exchanger, 9.
...Melting substance, 10...Shell portion, 12...Heat transfer tube, 13...Annular rack, 15...Motor, 16...
・Rotation axis center.

Claims (1)

[Claims] 1. A rotary drive device is provided to rotate the heat exchanger around an axis parallel to the tube axis of the heat transfer tube passing through the shell portion of the shell and tube type heat exchanger, and the high temperature passing through the heat transfer tube is provided in the shell portion. A regenerative heat exchanger, characterized in that a molten substance having a melting point is sealed in the middle of a temperature fluctuation range of a heat transfer medium, and a baffle plate that protrudes inward is provided on the outer plate of the body of the shell portion.