KR20010085003A - Twin Heat Exchanger of Filtering & Regenerative - Google Patents

Abstract

PURPOSE: A dual type waste heat exchanger of thermal storage material for a filter is provided to reduce the damage of a thermal storage unit and a heat transfer unit caused by a long combustion time by adopting the dual structure of a heat exchanger and to save fuel by recycling the heat of the thermal storage unit even though a boiler is run continuously for 24h. CONSTITUTION: Waste gas of 150-300deg.C of a boiler flows through a honeycomb ceramic filter(1) primarily. The ash of fuel as well as the remaining soot and dust of the gas is adsorbed by the surface tension of the honeycomb ceramic by flowing through plural latticed holes having a large sectional area. A condensate is generated by heat transfer out of a water jacket of a plate type heat exchanger and dropped into the ceramic for the filter. Thereby, the remaining sulfur of the waste gas is combined with water molecules. The sulfur oxide is adsorbed to the body of the honeycomb ceramic together with the filtered dust to prevent the life span of the heat exchanger from being shortened and to keep the thermal efficiency regular. The adsorbed dust and sludge is eliminated primarily by a tool and then secondarily by a high-pressure washing machine or a regular water hose.

Description

Twin structure waste heat exchanger of heat storage agent for filter {Twin Heat Exchanger of Filtering & Regenerative}

It is possible to reduce the lifespan and prevent environmental pollution of waste heat exchangers due to soot and sulfur generated after combustion in various fuels used for boilers, ie, solid fuels, liquid fuels, and gaseous fuels. It aims to reduce fuel consumption and continuous use of waste energy by absorbing and reusing it. In most industrial commercial boilers, waste heat recovery units have been installed between the outlet of the boiler exhaust and the chimney for fuel savings.

(Figure 2)

The conventional method performs heat exchange only during burner operation, which is limited in terms of unabsorbed high temperature heat passing through the boiler heating surface when the burner attached to the boiler is operated, and the spiral tube and fin tube (Fig. 7) are enlarged to increase the heat transfer area. Install the forced exhaust fan (Fig. 2) to eliminate the pressure loss accompanied by the batch production in diamond type to increase the installation cost and operation cost, and because the internal cleaning of the heat exchanger is difficult in structure, the efficiency decreases significantly and condensate generated during heat exchange Sulfur oxides and soot (soot) remaining in the combustion gas were stuck and accelerated corrosion, which blocked the flow path of the exhaust gas, which in turn shortened the life of the equipment, so the profits from the fuel savings were not as expected.

1. Thermal efficiency decreases due to the difficulty of cleaning the heat transfer surface of the existing tube type

Most waste heat exchangers are made of fin tube and spiral tube, and diamond array is burned out because hot exhaust gas is not properly discharged due to blockage of gas flow due to the sold out, sludge produced from fuel combustion gas, and condensate from heat exchanger. Abnormal explosions may occur inside the combustion chamber, which may lead to danger and operator anxiety.

2. Corrosion of the heating surface due to S + O2 = SO2 contained in solid fuel and liquid fuel combustion gases.It is combined with condensate generated by sulfur, oxygen, and heat conduction in the combustion gas of fuel. To reduce the life of heat exchanger

3. The burner attached to the boiler stops under certain conditions, so the heat exchange is stopped during burner rest.

As a result, thermal deviation of the reaction water is generated, which causes difficulty in energy control due to severe temperature deviation introduced into the boiler.

4. Loss of energy due to the release of heat into the heat transfer surface of the heat exchanger that was not absorbed.

No matter how efficient the heat exchanger is, the method of canceling Δp in the duct by using a forced exhaust fan does not absorb half the amount of heat exhausted for reasons such as shortening the residence time, as opposed to the condition of thermal efficiency. Therefore, the energy that can be used is lost to the atmosphere, leading to excessive consumption of fuel.

5. Conventional tube types are difficult to repair and repair of arranged tubes.

Existing heat exchangers are made densely by series connection of fin tube, so when welding water or heating surface is damaged due to low temperature corrosion and thermal stress, the leaked water cannot be located and repair is difficult.

Figure 1. Front view of the present invention

Figure 2. Heat Flow Chart of Existing Waste Heat Exchanger

Figure 3. Important three-part configuration diagram of the present invention

Figure 4. Heat flow chart of the present invention

Figure 5. Perspective view of heat exchanger

Figure 6. Left and Right Side View of Heat Exchanger Chamber

Figure 7. Magnification of Obstruction Guide

Figure 8. Existing tube type arrangement

Figure 9. Honeycomb Ceramic

Fig. 10.Honeycomb ceramic (filter section) perspective view

<Brief description of the main parts of the drawing>

1: 3way switching valve 2.3: 1st tower damper

4: recycle fan 5: feed water pump

6,7: Tower 2 Damper 8: Recycling Fan

9: water supply circulation pump

1. The waste gas of 150 ℃ ~ 300 ℃ from the boiler passes through the honeycomb ceramic (horizontal × vertical × height 150 × 150 × 150) (Fig. 10) filter which mainly functions as the filtration. Residual carbon sold out in heavy and heavy combustion passes through the lattice hole with enormous cross-sectional area, adsorbing dust by the surface tension of honeycomb ceramic, and outside the jacket of the filter heat exchanger, namely the plate heat exchanger. The condensate generated by heat conduction falls on the filter ceramic and eventually the sulfur remaining in the waste gas and the molecules in the water molecules combine, so that the sulfur oxides are adsorbed to the filtered dust and the body of the honeycomb ceramic. It can prevent the shortening of the heat exchanger and the deterioration of the heat efficiency in advance, and the adsorbed dust and sludge are first removed with a tool and then a high pressure washer or a general Easily removed with a water supply hose to maintain its original condition and treated wastewater and dust can be consigned.

2. The heat exchanger is manufactured as follows to increase the heat transfer area, delay of residence time of waste gas, and residence time of reaction water (Fig. 3-2).

In consideration of the contraction and expansion caused by the flow of heat in the heat exchanger, the heat exchanger is divided into several chambers and installed independently of each other (FIG. 5). 6-1) was installed to intensify the strength and increase the thermal efficiency, and the external angle of each chamber was 3 ° to 10 ° to actively induce the residence time and convection of the gas between each chamber (Fig. 5-1). If the obstruction guide plate is installed vertically with the interval of about 150mm by setting the obstruction guide plate in consideration of the cross section area of the boiler exhaust gas duct and the number of chambers, the exhaust gas is forced to act so as not to leave the heating surface. The guide plate also has the side effect that the dust that is not adsorbed by the filter unit is settled by gravity and inertia. In addition, taking into account the amount of water in the chamber, the tubes are arranged vertically in each chamber (FIG. 5), resulting in an enlarged heat transfer surface, and the pitch of the tubes and the tubes is limited to 80-100 mm.

In addition, as a method for heating the reaction water of the heat exchanger once again, a heater (FIGS. 5 and 6) is installed between the filter unit and the heat exchanger to increase the temperature of the reaction water before being sent to the boiler. It is possible to visually identify the repair part and the cleaning work that can be generated by bolting the external insulation surface to the heat exchange part manufactured as described above and give the ease of repair work and cleaning work.

The heat transfer area is usually 13-20M2, and it is made of stainless steel (STS304) in consideration of the supply and demand of materials.Thermal efficiency calculation is `` Hot water generation (weight per hour) x hot water specific heat x (heat inlet temperature-outlet temperature) of the heat exchanger '' ÷÷ By dividing the heat transfer area by the low calorific value of the fuel, the calorie value per 1 M2 can be obtained.

3. The heat storage honeycomb ceramic according to the present invention has an external shape of 150 × 150 × 300 (width × length × height), and one ceramic has two kinds of 25 × 25 holes and 40 × 40 holes in the height direction. 9) The component of ceramic is composed of SIO270% AL203 2.5%, heat resistance temperature is over 1000 ℃, has high thermal conductivity, and has high strength of 400N / mm2. It is constructed based on the exit duct cross-sectional area standard (1200 sheets / 1M2), and absorbs most of the heat that is not absorbed by the heat exchanger. If sludge occurs due to long time use in the heat storage unit, it can be cleaned with air pressure and water, and will be restored to its original function after cleaning. The device (filter unit, heat exchanger, and heat storage unit), which is largely combined as described above, is operated in the following manner.

The paired waste heat exchanger of the heat storage agent for the filter is composed of two towers. First, the hot waste gas passes through the filter part and then passes through the switching valve (Fig. 1-1) which moves to the timer at the designated time and is discharged to the No. 1 tower (Figs. 1-2 and 3). The amount of heat that has passed and is not absorbed is drained out of the heat storage unit and discharged. At this time, if the temperature detected by the temperature sensor TE between the heat exchanger and the heat accumulator is over 40 ° C, the water supply circulation pump and the recycle fan (Figs. 1-4 and 5) are driven and the time until the heat accumulator is just overheated The charged switching valve is closed in reverse (Fig. 1-1), the dampers in tower 1 (Figs. 1-2, 3) are closed, the two dampers in tower 2 (Figs. 1-6, 7) are opened and the gas is in tower 2. Will be discharged. The second tower heat exchanger performs an endothermic action, and the heat storage unit starts the heat storage action and performs heat exchange in the same manner as the first tower. At the same time, the tower 1 serves to spray the heat stored in the heat exchanger's heat transfer surface by the recycling fan continuously by the waste gas blocking, and is set in the tower temperature sensor (TE) below 40 ℃. When it is lowered to, the water circulation pump and the recycling fan stop to enter the resting state.

Here, TE of towers 1 and 2 is operated by recycling fan and feed water circulation pump when the temperature is higher than the setting temperature 40 ℃ and stops when the temperature is lower than that. After that, just before the heat accumulator of tower 2 is overheated, the gas is discharged to tower 1 again by the switching valve, and the exhaust gas is blocked in the same way as tower 1 in tower 2. It sprays high temperature on the heat surface and the operation is controlled by the second tower TE.

In this way, a continuous 24-hour boiler will absorb most of the heat that is wasted.

The waste heat exchanger structure of the heat storage agent for the filter according to the present invention has a plate-like heat transfer surface, and thus, a repairable part, that is, a weld bead is disposed at the corner of the structure, so that the repair is easy and the cleaning work and the heat transfer surface area can be visually observed. The high heat waste gas discharged from the boiler makes it possible to actively use the waste heat as the filter unit, the heat exchange unit and the heat storage unit, and the two tower structures can flexibly cope with the continuous use of the boiler. Reducing the time saves fuel, contributing to each operator's production cost savings and energy savings.

Claims (1)

At the inlet of the present invention, a symmetrical inclination is installed at a predetermined angle with the filter unit adsorbing the soot and the sulfur oxides, and the plate heat exchanger assembly which enlarges the retention surface of the waste gas is not absorbed even through the heat transfer surface of the heat exchange unit. Dual-type waste heat exchanger for filter heat accumulator which accumulates most of heat in honeycomb ceramic which is heat storage part and reuses the accumulated heat amount even in the environment where boiler is operated for 24 hours