CN115896407A - Tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger - Google Patents

Abstract

The invention discloses a tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger, which comprises a flange and a shell which are fixedly connected together, a pair of U-shaped heat exchange tubes positioned in the shell and a magnesium oxide heat insulation filler positioned in the shell and used for fixing the U-shaped heat exchange tubes, wherein the magnesium oxide heat insulation filler is sealed at the port of the shell through high temperature resistant sealant, the lower ends of the pair of U-shaped heat exchange tubes, which extend out of the flange, are connected with a warm water inlet connecting pipe through a warm water inlet distributing pipe which is commonly connected, and the upper ends of the pair of U-shaped heat exchange tubes, which extend out of the flange, are connected with a hot water outlet connecting pipe through a hot water outlet collecting pipe which is commonly connected, the warm water inlet connecting pipe can be connected to a warm water source, and the hot water outlet connecting pipe can be sequentially connected with a water pump, a hot water supply pipeline and a lithium bromide refrigerating system. The invention adopts the liquid carrier warm water to slowly absorb heat to form high-temperature hot water which can be supplied to a working heat source of a lithium bromide system, and the temperature of the box is reduced according to the annealing slow cooling working condition.

Description

Tunnel furnace annealing heat treatment slow cooling heat recovery high temperature differential heat exchanger

【Technical field】

The invention relates to a tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger, which belongs to the technical field of recovery and utilization of high temperature difference waste heat of a heat treatment tunnel furnace.

【Background technique】

During the shearing and punching process of silicon steel sheets for motors, plastic deformation will cause changes in internal stress and physical properties, resulting in increased hardness in the cold work hardening zone, deterioration of magnetic permeability, and increased iron loss. For this reason, it is necessary to place the cold-rolled workpiece in a continuous tunnel furnace to perform annealing and slow cooling treatment when passing through the annealing box while the cold-rolled workpiece is annealing and slow cooling. Hours and cooling down to about 450 ℃ ~ 500 ℃, the traditional annealing slow cooling method is to use the indirect air cooling method, when it reaches the blue temperature, the fan controls the box temperature (see patent number 201010229889.2, the patent name is a cold Continuous annealing and bluing process of rolled silicon steel sheet punching workpiece).

How to recover the waste heat generated during the annealing and slow cooling process and use it as the working heat source required for lithium bromide refrigeration is really a subject to be studied and worked hard by those skilled in the art.

【Content of invention】

The object of the present invention is to provide a tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger.

For this reason, the present invention provides following technical scheme:

Tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger, the heat exchanger is a high temperature difference slow heat absorption heat exchanger, which is installed in the annealing box of the tunnel furnace, including the flange fixed on the outer wall of the annealing box , the housing with the port fixed to the flange, a pair of U-shaped heat exchange tubes located in the housing, and a magnesium oxide heat-insulating filler for fixing the U-shaped heat exchange tubes located in the housing, the oxide Magnesium insulation filling material is sealed near the port of the shell by high temperature resistant sealant, and the lower ends of a pair of U-shaped heat exchange tubes protruding from the flange are connected with the warm water inlet connection pipe through the common connected warm water inlet distribution pipe Each upper end protruding out of the flange is connected with the hot water outlet connecting pipe through the common hot water outlet collecting pipe, the warm water inlet connecting pipe can be connected to the warm water supply source, and the hot water outlet connecting pipe can be connected with the water pump, hot water supply pipeline and LiBr refrigeration system.

The present invention has following advantage and positive effect:

The liquid carrier warm water is used as the heat exchange medium for annealing heat treatment. The annealing box of the tunnel furnace needs to be cooled slowly. Finally, the liquid carrier warm water flowing in the U-shaped heat exchange tube continues to slowly absorb the heat outside the tube and in the tunnel furnace. The warm water after the internal heat is turned into hot water and can be provided to the lithium bromide refrigeration system as a working heat source. The lithium bromide refrigeration system then generates cold energy through energy conversion to supply the workshop to cool down. This will greatly reduce the waste of industrial energy and achieve the goal of waste heat recovery and utilization. Purpose.

The magnesia thermal insulation filler not only has thermal insulation performance but also slow heat transfer, which ensures that the U-shaped heat exchange tube can slowly absorb the heat that the annealing box needs to cool down from high temperature through slow cooling in the environment of high temperature difference.

After adopting the above-mentioned technical solution, it is possible to abandon the indirect air-cooling method of the annealing and slow cooling mentioned in the background technology, thereby saving the power consumption required by the fan for air-cooling.

【Description of drawings】

Fig. 1 is a schematic diagram of the structure of the present invention;

Fig. 2 is A-A sectional view among Fig. 1;

Fig. 3 is a B-B sectional view in Fig. 1 .

【Detailed ways】

Please refer to Figures 1 to 3, the tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger, the heat exchanger is a high temperature difference slow heat absorption heat exchanger, which is installed in the tunnel furnace (conventional equipment not shown) In the annealing box, it is used to recover the high temperature difference waste heat generated by the slow cooling and cooling in the box during the annealing process, including the flange 1 fixed on the outer wall of the annealing box, the shell 2 with the port facing the flange welded and fixed, and the shell located in the shell A pair of U-shaped heat exchange tubes 5 and a magnesia heat-insulating filler 3a for fixing the U-shaped heat-exchange tubes in the casing, the magnesia heat-insulation filler is sealed by a high-temperature-resistant sealant 3b Closed at the port of the shell 2, wherein, the lower ends of a pair of U-shaped heat exchange tubes 5 protruding from the flange 1 are jointly connected with a warm water inlet distribution pipe 42, and the warm water inlet distribution pipe 42 is connected to A warm water inlet connection pipe 41, which can be connected to a warm water supply source; a pair of U-shaped heat exchange heat exchange pipes 5 protruding from each upper end of the flange 1 are jointly connected with a hot water outlet collection pipe 61. The water outlet collecting pipe 61 is connected to a hot water outlet connecting pipe 62, which can be connected to the external water pump, hot water supply pipeline and lithium bromide refrigeration system in turn, and the high temperature hot water is used to provide the lithium bromide refrigeration system with the working heat source required for refrigeration .

The liquid carrier water is used as the heat exchange medium to absorb the thermal energy that needs high temperature and slow cooling in the annealing furnace box of the tunnel furnace, and the high temperature hot water obtained by using the waste heat transfer can be pressurized by the water pump to promote the high temperature hot water in the generator of the lithium bromide refrigeration system Work circulation flow, as the heat source of lithium bromide refrigeration system.

Shell 2 is made of stainless steel seamless round tube; U-shaped heat exchange tube 5 is made of seamless copper tube with excellent thermal conductivity; magnesium oxide heat insulating filler 3a is filled by vibration filling to fix the copper tube on the shell 2, it not only has thermal insulation performance but also slow heat transfer, so that the U-shaped heat exchange heat exchange tube 5 slowly absorbs the waste heat that the annealing box needs to be cooled by high temperature through slow cooling under the environment of high temperature difference, so that the annealing box The temperature is lowered as needed.

Its water flow rate of the warm water that enters the warm water inlet connecting pipe 41 adopts the prior art to be adjustable, specifically by measuring the water temperature of its high-temperature hot water flowing out of the hot water outlet connecting pipe 62.

The water circuit circulation during the specific implementation is as follows: the low temperature water is supplied by the warm water supply source and flows into the warm water inlet connecting pipe 41, and the warm water flowing through the warm water inlet connecting pipe 41 enters the warm water inlet distribution pipe 42 by self-priming and passes through two output pipes set separately from the pipe Each port flows into the lower port of a corresponding U-shaped heat exchange tube 5, so that the warm water flowing in a pair of U-shaped heat exchange tubes 5 absorbs the heat outside the tube and in the box to promote temperature rise. The resulting hot water continues to flow toward the top of each pair of U-shaped heat exchange tubes 5 in a state of temperature difference, and flows into the two sides of the hot water outlet collecting tube 61 in two ways through the upper ports of the two pairs of heat exchange tubes 5 . After the input nozzles are collected, they flow through the hot water outlet connecting pipe 62, and the high-temperature hot water flowing out of the hot water outlet connecting pipe 62 can be supplied to the generator of the lithium bromide refrigeration system through the hot water supply pipeline under the pressurization of the water pump. And it works and circulates in the generator as the heat source of the lithium bromide refrigeration system.

The water pump, hot water supply pipeline and lithium bromide refrigeration system all adopt the existing technology.

After adopting this device, the temperature of the annealing box of the tunnel furnace can be slowly cooled from 800°C to 450°C to 500°C, and this device absorbs the high temperature difference heat generated in this slow cooling process.

Claims (1)

1. A tunnel furnace annealing heat treatment slow cooling heat recovery high temperature difference heat exchanger is characterized in that: the heat exchanger is a high-temperature difference slow heat absorption type heat exchanger which is arranged in an annealing box body of the tunnel furnace,

comprises a flange fixed on the outer wall of an annealing box body, a shell with a port fixed towards the flange, a pair of U-shaped heat exchange tubes positioned in the shell and magnesia heat insulation filler positioned in the shell and used for fixing the U-shaped heat exchange tubes, wherein the magnesia heat insulation filler is sealed in the shell close to the port of the shell through high-temperature-resistant sealant, the lower ends of the pair of U-shaped heat exchange tubes, which extend out of the flange, are connected with a warm water inlet connecting pipe through a warm water inlet distributing pipe which is commonly connected, while the upper ends of the pair of U-shaped heat exchange tubes, which extend out of the flange, are connected with a hot water outlet connecting pipe through a hot water outlet collecting pipe which is commonly connected,

the warm water inlet connecting pipe can be connected to a warm water supply source, and the hot water outlet connecting pipe can be sequentially externally connected with a water pump, a hot water supply pipeline and a lithium bromide refrigerating system.

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