CN202494345U - Industrial furnace waste heat recovery system - Google Patents

Abstract

The utility model discloses an industrial furnace waste heat recovery system, which comprises a total smoke exhaust channel and a waste heat recovery device connected to the total smoke exhaust channel, which is composed of a primary heat exchange device and a secondary heat exchange device. The air/water heat exchanger with water inlet and outlet on the smoke channel, the secondary heat exchange device is a water/water heat exchanger with primary water inlet and outlet and secondary water inlet and outlet; the water outlet of the air/water heat exchanger is connected to the The primary water inlet of the water/water heat exchanger is connected, the primary water outlet of the water/water heat exchanger is connected with the water inlet of the air/water heat exchanger; the cold water pipeline to be heated is connected with the water/water heat exchanger The secondary water inlet of the water/water heat exchanger is connected, and the secondary water outlet of the water/water heat exchanger is connected with the heat storage pool through the hot water pipeline. The utility model has the advantages of simple structure and high waste heat utilization rate. While effectively reducing the flue gas discharge temperature of the industrial furnace to about 130°C, it can also obtain hot water at 60°C to meet people's water supply and heating needs.

Description

Industrial furnace waste heat recovery system

technical field

The utility model relates to waste heat recovery of high-temperature flue gas of industrial gas (fuel oil) furnaces, in particular to a waste heat recovery system of industrial furnaces.

Background technique

At present, 90% of China's energy comes from chemical fuels, and this form will not change in the short term (15-20 years). Since China is a resource-poor country, it needs to import a large amount of energy to support the needs of rapid economic development, and energy is largely controlled by developed countries through the futures market. A practical strategy has been valued by the government, and a new concept has been put forward: "energy saving" is also an important energy source.

A prominent aspect of thermal energy conservation is the recovery and utilization of waste heat. The exhaust gas temperature of the flue gas produced during the production process of the industrial gas (fuel) furnace is still high (up to 350-700°C) after the first waste heat utilization of the industrial furnace, and the flue gas with a temperature of 350-700°C is directly discharged in the The atmosphere not only wastes energy, but also pollutes the environment. If the exhaust gas temperature can be reduced to below 180°C (or even lower), it can not only achieve energy saving and emission reduction, reduce production and operation costs, but also improve the quality of life of the people.

At present, the coke ovens of large-scale domestic iron and steel plants can use waste heat to generate electricity. But at the same time, there are a large number of metal heat treatment furnaces of different sizes in my country, with power ranging from hundreds to thousands of kilowatts. Since the thermal efficiency of the heat treatment furnace is only about 50%, how to make good use of this part of waste heat has very great practical significance.

Contents of the invention

The purpose of the utility model is to provide an industrial furnace waste heat recovery system, which can fully recover the high-temperature flue gas discharged in the production of the industrial furnace, so as to achieve a good energy-saving purpose.

In order to achieve the above object, the utility model can take the following technical solutions:

The industrial furnace waste heat recovery system described in the utility model includes a total smoke exhaust channel connected with a plurality of industrial grate flues and a waste heat recovery device connected to the total smoke exhaust channel through a smoke exhaust fan. The recovery device is composed of a primary heat exchange device and a secondary heat exchange device; the primary heat exchange device is an air/water heat exchanger connected in series on the total smoke exhaust channel through a control valve, and the secondary heat exchange device The heat device is a water/water heat exchanger with primary water inlet and outlet and secondary water inlet and outlet; the water outlet of the air/water heat exchanger is connected with the primary water inlet of the water/water heat exchanger through a pipeline, The first-stage water outlet of the water/water heat exchanger communicates with the water inlet of the air/water heat exchanger through a pipeline and a circulating pump arranged on the pipeline; the cold water pipeline to be heated communicates with the water inlet through a valve. The secondary water inlet of the water/water heat exchanger is connected, and the secondary water outlet of the water/water heat exchanger is connected with the heat storage tank through the hot water pipeline and the water pump arranged on the hot water pipeline.

The air/water heat exchanger is a heat pipe heat exchanger, and the water/water heat exchanger is a plate heat exchanger.

A bypass smoke exhaust branch is set between the general smoke exhaust channel behind the exhaust fan and the smoke exhaust channel at the rear of the gas/water heat exchanger exhaust port, and a control valve is set on the bypass smoke exhaust branch.

The cold water pipeline to be heated includes a circulation pipeline drawn from a water storage tank and a supplementary water pipeline introduced from a tap water pipe network connected in parallel.

The utility model has the advantages of simple structure and high waste heat utilization rate. While effectively reducing the flue gas discharge temperature of the industrial furnace to about 130°C, it can also obtain hot water at 60°C to meet people's water supply and heating needs.

Description of drawings

Fig. 1 is the system schematic diagram of the utility model.

Detailed ways

As shown in Figure 1, the industrial furnace waste heat recovery system described in the utility model includes a total smoke exhaust channel 2 connected with a plurality of industrial furnace 1 exhaust channels and connected to the total smoke exhaust channel 2 through a smoke exhaust fan 3 The waste heat recovery device, the waste heat recovery device is composed of a primary heat exchange device and a secondary heat exchange device; the primary heat exchange device is connected in series to the main smoke exhaust channel 2 through the control valve 4. Heat pipe gas/water with water inlet and outlet Heat exchanger 5, the secondary heat exchange device is a plate water/water heat exchanger 6 with primary water inlet and outlet and secondary water inlet and outlet; the water outlet of heat pipe air/water heat exchanger 5 is connected with the plate water/water The primary water inlet of the heat exchanger 6 is connected, and the primary water outlet of the plate water/water heat exchanger 6 is connected with the heat pipe gas/water heat exchanger 5 through the pipeline and the circulation pump 7 and safety valve 14 arranged on the pipeline. The water inlet is connected; the circulation pipeline 12 drawn from the reservoir 9 and the supplementary water pipeline 13 introduced by the tap water pipe network connected in parallel are connected with the secondary water inlet of the heat pipe water/water heat exchanger 6 through a valve , the secondary water outlet of the plate water/water heat exchanger 6 communicates with the heat storage pool 9 through the hot water pipeline and the water pump 8 arranged on the hot water pipeline; A bypass smoke exhaust branch 10 is arranged between the smoke exhaust channels at the rear of the smoke exhaust port of the heat pipe gas/water heat exchanger 5 , and a control valve 11 is arranged on the bypass smoke exhaust branch 10 .

When the utility model is working, the high-temperature smoke exhaust from multiple heating furnaces 1 is converged into a total smoke exhaust channel 2 for forced smoke exhaust, and the smoke exhaust pressure is controlled by the frequency conversion smoke exhaust fan 3, and the heat pipe heat exchanger 5 is connected in series. On the main smoke exhaust channel 2, a pair of water inlet and outlet of the heat exchanger 5 is connected to demineralized water, and the circulation pump 7 is used to circulate through the heat exchanger 5 for heat exchange, and obtain high-temperature demineralized water with a maximum temperature of 120°C; the high-temperature demineralized water is passed through The plate heat exchanger 6 performs secondary heat exchange, and the other pair of water inlets and outlets of the plate heat exchanger 6 are respectively connected to tap water or a reservoir 9 to obtain hot water at about 60°C and store it in the reservoir 9 for heating or domestic use. Reservoir 9 can buffer the pressure of water peak period. When the hot water in the reservoir 9 is full and the water temperature exceeds 70° C., the waste heat recovery system can be turned off, and the flue gas can be directly discharged through the bypass smoke exhaust branch 10 .

Claims (4)

1. An industrial furnace waste heat recovery system, including a total smoke exhaust channel (2) connected to multiple industrial furnaces (1) exhaust channels and connected to the total smoke exhaust channel (2) through a smoke exhaust fan (3) ) on the waste heat recovery device, which is characterized in that: the waste heat recovery device is composed of a primary heat exchange device and a secondary heat exchange device; ) on the air/water heat exchanger (5) with water inlet and outlet, and the secondary heat exchange device is a water/water heat exchanger (6) with primary water inlet and outlet and secondary water inlet and outlet; the air The water outlet of the water/water heat exchanger (5) is connected to the primary water inlet of the water/water heat exchanger (6) through a pipeline, and the primary water outlet of the water/water heat exchanger (6) is The pipeline and the circulation pump (7) arranged on the pipeline are connected with the water inlet of the air/water heat exchanger (5); the cold water pipeline to be heated is connected to the water/water heat exchanger (6) through a valve ), the secondary water inlet of the water/water heat exchanger (6) passes through the hot water pipeline and the water pump (8) set on the hot water pipeline and the heat storage pool (9) connected. 2. The industrial furnace waste heat recovery system according to claim 1, characterized in that: the air/water heat exchanger (5) is a heat pipe heat exchanger, and the water/water heat exchanger (6) is a plate heat exchanger heater. 3. The industrial furnace waste heat recovery system according to claim 1 or 2, characterized in that: the total smoke exhaust channel behind the exhaust fan (3) and the rear exhaust port of the gas/water heat exchanger (5) A bypass smoke exhaust branch (10) is arranged between the smoke exhaust channels, and a control valve (11) is arranged on the bypass smoke exhaust branch (10). 4. The industrial furnace waste heat recovery system according to claim 1, characterized in that: the cold water pipeline to be heated includes a circulation pipeline (12) drawn from a water storage tank (9) connected in parallel and a tap water pipeline The water supply pipeline (13) introduced by the net.

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