A waste heat utilization device based on industrial waste gas

Abstract

This utility model discloses a waste heat utilization device based on industrial waste gas, comprising: a waste heat collection unit installed on the waste gas emission pipeline, a conveying pipeline connected to the waste heat collection unit, an underground heat exchange unit located at the end of the conveying pipeline, and a control unit for monitoring and automatic control. This application introduces an intelligent control scheme, which monitors the operating parameters of the heat exchanger and pipeline (such as temperature, pressure, flow rate, etc.) in real time and automatically controls the regulating valve based on the monitoring data, ensuring that the entire device always operates under optimal conditions. When a fault occurs, the valve automatically closes, thereby solving the problem of automated control for long-distance transmission and reducing labor and maintenance costs.

Description

Technical Field

[0001] This utility model relates to the field of agricultural waste heat utilization technology, specifically to a device for agricultural applications that utilizes the waste heat of industrial waste gas (such as waste gas from brick factory cooling towers). Background Technology

[0002] In some industrial manufacturing settings, such as brick factories, cooling towers emit large amounts of waste gas containing residual heat during production. This waste heat is typically released directly into the atmosphere, resulting in energy waste. Agricultural production, such as crop cultivation and greenhouses, has high requirements for soil and irrigation water temperatures, especially during cold seasons, requiring additional energy input to maintain a suitable growing environment. Therefore, how to effectively collect and utilize the waste heat from industrial cooling towers in agricultural applications, achieving energy recycling, is a pressing issue that needs to be addressed.

[0003] Currently, various technologies have been developed for waste heat recovery. For example, the invention patent with publication number CN118936189A discloses a waste heat recovery and utilization device for combustion exhaust gas. This device includes a main body, with a water inlet pipe fixed to the top of one side and a drain pipe fixed to the bottom of the other side. A fan is fixed to the top of the main body, and an air inlet main pipe is fixed to the outlet of the fan, located inside the main body. An exhaust main pipe is fixed to one side of the main body, and several corrugated branch pipes are fixed to the bottom of the air inlet main pipe. Another example is the utility model patent with authorization publication number CN206669782U, which discloses an environmentally friendly and energy-saving chimney waste heat recovery and reuse device. This device includes a base, with an electrostatic dust collector fixedly connected to the top of the base. A connecting pipe is fixedly connected to the top of the electrostatic dust collector, and a main housing is fixedly connected to the top of the connecting pipe. Water inlet and outlet pipes are respectively connected to the left and right ends of the main housing. A waste heat recovery unit is fixedly connected to the top of the cold water tank and to the hot water tank. However, existing waste heat recovery devices are mostly used in short-distance applications and are difficult to adapt to the agricultural field where long-distance transmission is required. Furthermore, in long-distance agricultural applications, automated control cannot be achieved. Utility Model Content

[0004] A brief overview of embodiments of the present invention is provided below to provide a basic understanding of certain aspects of the invention. It should be understood that this overview is not an exhaustive summary of the invention. It is not intended to identify key or essential parts of the invention, nor is it intended to limit the scope of the invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to the more detailed description that follows.

[0005] The purpose of this invention is to provide an industrial waste gas waste heat utilization system that can achieve long-distance transmission, so as to solve the problems mentioned in the background art.

[0006] Specifically, this utility model discloses a waste heat utilization device based on industrial waste gas, comprising: a waste heat collection unit installed on a waste gas emission pipeline, a conveying pipeline connected to the waste heat collection unit, an underground heat exchange unit located at the end of the conveying pipeline, and a control unit for monitoring and automatic control; the control unit is installed on the conveying pipeline and includes a first regulating valve, a second regulating valve, a pressure transmitter, a pressure relief valve, a flow transmitter, a temperature acquisition device, a PLC controller, and a storage tank; the waste heat collection unit is divided into two paths, one of which passes sequentially through the pressure transmitter, the pressure relief valve, the flow transmitter, and the second regulating valve, and finally connects to the conveying pipeline; the other path passes through the storage tank and then connects to the conveying pipeline; the first regulating valve is installed at the inlet end of the storage tank, and the outlet of the storage tank is connected to the flow transmitter; the storage tank is provided with a placement port for the temperature acquisition device, and the output end of the temperature acquisition device is connected to the temperature transmitter; the output ends of the pressure transmitter, the flow transmitter, and the temperature transmitter are connected to the input end of the PLC controller, and the output end of the PLC controller is connected to the control end of the pressure relief valve and the second regulating valve.

[0007] The control unit ensures that waste heat from industrial exhaust gases is used efficiently and safely in agricultural applications through real-time monitoring and automatic adjustment, thereby improving energy efficiency and reducing production costs.

[0008] As a feasible solution, the waste heat collection unit can be a heat exchanger or a waste heat boiler, which is installed on the exhaust gas discharge pipe of the brick factory's heat dissipation tower to collect waste heat from the exhaust gas.

[0009] As a feasible solution, the conveying pipeline is connected to a waste heat collection unit to transport the collected heat transfer medium to agricultural land. The conveying device includes an insulated pipeline and a circulating pump. The insulated pipeline is a prefabricated direct-buried insulated pipeline or a composite insulated pipeline to reduce heat loss during transport. The circulating pump is selected based on factors such as the flow rate, head, and pipeline resistance of the heat transfer medium to ensure stable flow of the heat transfer medium within the pipeline.

[0010] As a feasible solution, underground heat exchange units are installed underground in agricultural land to transfer heat from the heat transfer medium to the soil. The underground heat exchange unit can be a buried pipe heat exchanger or an injection-type heat exchange device.

[0011] Furthermore, this utility model also includes a waste gas treatment unit between the waste gas emission pipe and the waste heat collection unit, the waste gas treatment unit including a filtration device and / or an adsorption device.

[0012] The filtration system is a multi-stage system, including a pre-filter, a medium-efficiency filter, and a high-efficiency filter, which progressively remove particulate matter, dust, and harmful gases from the exhaust gas. The pre-filter can be made of metal mesh or non-woven fabric and primarily filters larger particles and dust, such as brick dust and sand particles in industrial exhaust gas. The medium-efficiency filter can be made of non-woven fabric or filter paper to further remove smaller particles and harmful gases. The high-efficiency filter can use a high-efficiency filter element, such as a HEPA filter, to remove fine particles and harmful gases, ensuring that harmful substances in the exhaust gas are effectively filtered.

[0013] The adsorption device employs either activated carbon adsorption or molecular sieve adsorption. Activated carbon adsorption utilizes the adsorption properties of activated carbon to remove organic matter and harmful gases such as sulfur dioxide and nitrogen oxides from waste gas. Molecular sieve adsorption uses molecular sieve adsorbents, which have high adsorption capacity and selectivity, effectively removing moisture and harmful gases from waste gas.

[0014] This utility model's industrial waste gas waste heat agricultural utilization system, through the rational arrangement of waste heat collection units, conveying pipelines, underground heat exchange units, control units, and agricultural application devices, achieves effective collection of waste heat from industrial cooling towers and efficient utilization in the agricultural field, and has the following beneficial effects:

[0015] 1. By introducing an intelligent control scheme, the operating parameters of the heat exchanger and pipeline (such as temperature, pressure, flow rate, etc.) are monitored in real time, and the regulating valve is automatically controlled according to the monitoring data to ensure that it always operates under the best conditions. When a fault occurs, the valve is automatically shut off, thereby solving the problem of automated control for long-distance transmission and reducing labor and maintenance costs.

[0016] 2. Improve energy efficiency, reduce energy waste, and lower agricultural production costs; at the same time, promote crop growth, increase crop yield and quality, and increase farmers' income.

[0017] 3. It reduces dependence on traditional energy sources and lowers greenhouse gas emissions, resulting in significant environmental benefits. Attached Figure Description

[0018] This invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts. These drawings, together with the following detailed description, are incorporated in and form part of this specification, and are used to further illustrate preferred embodiments of the invention and explain the principles and advantages of the invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of the waste heat utilization device of this utility model;

[0020] Figure 2 This is a schematic block diagram of the control unit of this utility model. Detailed Implementation

[0021] Embodiments of the present invention will now be described with reference to the accompanying drawings. Elements and features described in one drawing or embodiment of the present invention may be combined with elements and features shown in one or more other drawings or embodiments. It should be noted that, for clarity, representations and descriptions of components and processes unrelated to the present invention and known to those skilled in the art have been omitted from the drawings and description.

[0022] In the description of this utility model, it should be understood that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] See Figure 1 An embodiment of the present invention provides a waste heat utilization device based on industrial waste gas, comprising: a waste heat collection unit installed on a waste gas emission pipeline, a waste gas treatment unit, a conveying pipeline connected to the waste gas treatment unit, an underground heat exchange unit located at the end of the conveying pipeline, and a control unit for monitoring and automatic control.

[0024] The waste heat collection unit can be a heat exchanger or a waste heat boiler, installed on the exhaust pipe of the brick factory's heat dissipation tower to collect waste heat from the exhaust gas. When the exhaust gas flows through the waste heat collection unit, the heat is transferred through the side wall of the waste heat collection unit to the heat transfer medium on the other side, such as water or antifreeze, thus achieving waste heat collection.

[0025] The conveying pipeline is connected to the waste heat collection unit to transport the collected heat transfer medium to agricultural land. The conveying device includes insulated pipes and a circulating pump. The insulated pipes are prefabricated direct-buried insulated pipes or composite insulated pipes to reduce heat loss during transportation. The circulating pump is selected based on factors such as the flow rate, head, and pipe resistance of the heat transfer medium to ensure stable flow of the heat transfer medium within the pipeline.

[0026] Underground heat exchange units are installed underground in agricultural land to transfer heat from the heat transfer medium to the soil. These units can be either buried pipe heat exchangers or injection-type heat exchangers. Buried pipe heat exchangers typically use U-shaped or spiral buried pipes made of high-molecular materials such as polyethylene, offering good corrosion resistance and insulation. Injection-type heat exchangers utilize drilling technology to create wells in the farmland, injecting the heat transfer medium directly into the underground aquifer or pores through injection pipes, ensuring full contact and heat exchange with the soil.

[0027] The control unit is used for monitoring and control. By monitoring key parameters in real time and automatically adjusting the operating state of the equipment according to the preset control logic of the PLC device, it ensures long-distance transportation. This application introduces sensors (for measuring temperature, pressure, and flow rate) and an intelligent controller to monitor the operating parameters of the heat exchanger (such as temperature, pressure, and flow rate) in real time and automatically adjust the operating state of the heat exchanger based on the monitoring data, ensuring that it always operates under optimal conditions.

[0028] See Figure 2 The control unit is installed on the conveying pipeline and includes a first regulating valve, a second regulating valve, a pressure transmitter, a pressure relief valve, a flow transmitter, a temperature acquisition device, a PLC controller, and a storage tank. The waste heat collection unit is divided into two paths: one path passes through the pressure transmitter, the pressure relief valve, the flow transmitter, and the second regulating valve in sequence, and finally connects to the conveying pipeline; the other path passes through the storage tank before connecting to the conveying pipeline. The first regulating valve is installed at the inlet end of the storage tank, and the outlet of the storage tank is connected to the flow transmitter. The storage tank has a placement port for the temperature acquisition device, and the output end of the temperature acquisition device is connected to the temperature transmitter. The output ends of the pressure transmitter, the flow transmitter, and the temperature transmitter are connected to the input end of the PLC controller, and the output end of the PLC controller is connected to the control end of the pressure relief valve and the second regulating valve.

[0029] In the control unit, the first regulating valve is installed on the pipeline to control the flow and pressure of the heat transfer medium (such as hot water or steam) to ensure stable system operation. A pressure transmitter (PT) monitors the pressure in the pipeline in real time and transmits the pressure data to the PLC controller. The PLC controller determines the pressure based on a preset threshold; when the system pressure exceeds the safety threshold, the pressure relief valve automatically opens to release excess pressure. A storage tank stores the heat transfer medium after heat exchange, acting as a buffer to balance system supply and demand. A temperature acquisition unit monitors the temperature of the heat transfer medium and transmits the data to a temperature transmitter. The temperature transmitter (TT) converts the data from the temperature acquisition unit into an electrical signal and transmits it to the PLC controller. A flow transmitter (FT) monitors the flow rate of the heat transfer medium in the pipeline and transmits the flow rate data to the PLC controller. The second regulating valve adjusts the opening of the delivery pipeline according to the instructions of the PLC controller, controlling the flow rate of the heat transfer medium. The PLC controller receives signals from the pressure transmitter, temperature transmitter, and flow transmitter, analyzes and processes them according to preset logic, and automatically adjusts the system's operating status. The delivery pipeline transports the heat transfer medium to the agricultural application area.

[0030] As a specific implementation method, agricultural application devices can also be installed, which can be combined with underground heat exchange units to apply the heated soil or water to agricultural production. These devices can include crop planting areas, irrigation systems, etc. Raising soil temperature promotes crop root growth and nutrient absorption, especially during low-temperature periods such as spring, effectively shortening the crop growth cycle and increasing yield and quality. Furthermore, water heated by waste heat can be used to irrigate crops, avoiding damage to crop roots from low-temperature irrigation water.

[0031] The exhaust gas in the exhaust gas emission pipe often contains components such as sulfur dioxide. When it comes into contact with steam or moisture, it will form sulfurous acid, which will corrode the tube sheet and weld seam, causing leakage at the tube sheet or weld seam. Therefore, this utility model sets up an exhaust gas treatment unit between the exhaust gas emission pipe and the waste heat collection unit. The exhaust gas treatment unit includes a filtration device and / or an adsorption device.

[0032] The filtration device is a multi-stage filtration system, which may include a pre-filter, a medium-efficiency filter, and a high-efficiency filter to gradually remove particulate matter, dust, and harmful gases from the exhaust gas.

[0033] Primary filters can be made of metal mesh or non-woven fabric and are mainly used to filter larger particles and dust, such as brick dust and sand particles in industrial waste gas.

[0034] Medium-efficiency filters can be made of non-woven fabric or filter paper to further remove smaller particles and harmful gases.

[0035] High-efficiency filters can use high-efficiency filter elements, such as HEPA filters, to remove fine particulate matter and harmful gases, ensuring that harmful substances in exhaust gas are effectively filtered.

[0036] The adsorption device employs either activated carbon adsorption or molecular sieve adsorption. Activated carbon adsorption utilizes the adsorption properties of activated carbon to remove organic matter and harmful gases such as sulfur dioxide and nitrogen oxides from waste gas. Molecular sieve adsorption uses molecular sieve adsorbents, which have high adsorption capacity and selectivity, effectively removing moisture and harmful gases from waste gas.

[0037] The exhaust gas treatment unit is located upstream of the waste heat collection unit. This allows harmful substances in the exhaust gas to be filtered and treated before entering the waste heat collection unit, preventing them from entering the heat exchanger and subsequent pipelines and causing corrosion to the pipes and equipment.

[0038] Taking a brick factory as an example, in practical applications, a heat exchanger is first installed on the exhaust pipe of the brick factory's heat exchange tower as a waste heat collection unit. When the heat exchange tower emits waste gas during the brick factory's production process, it first passes through a multi-stage filter in the waste gas treatment unit to remove harmful gases from the exhaust gas. Then, the treated waste gas flows through the heat exchanger, and heat is transferred to the water inside the heat exchanger through the heat exchanger wall, producing hot water. Then, the hot water is transported to agricultural land through a pipeline consisting of insulated pipes and a circulating pump. Underground, a buried pipe heat exchanger is laid as an underground heat exchange unit. The hot water circulates within the buried pipe, exchanging heat with the surrounding soil through the pipe walls, raising the soil temperature. Finally, in the crop planting area, the soil with the increased temperature is used for crop planting, promoting crop growth. At the same time, the water heated by waste heat can also be used to irrigate crops through an irrigation system, avoiding damage to crop roots caused by low-temperature irrigation water. The above process can be described as follows:

[0039] Brick factory heat dissipation tower exhaust outlet → exhaust gas treatment unit → heat exchanger (exhaust gas inlet, heat transfer medium outlet) → heat transfer medium (hot water or steam) → insulated pipe → circulating pump → agricultural land → underground heat exchange unit (buried pipe heat exchanger or injection heat exchange device) → crop planting area (to increase soil temperature) or irrigation system (preheating water).

[0040] This utility model's industrial waste gas waste heat agricultural utilization system, through the rational arrangement of waste heat collection units, conveying devices, underground heat exchange units, and agricultural application devices, achieves effective collection of waste heat from brick factory cooling towers and efficient utilization in the agricultural field, and has the following beneficial effects:

[0041] Improve energy efficiency, reduce energy waste, and lower agricultural production costs.

[0042] To promote crop growth, increase crop yield and quality, and increase farmers' income.

[0043] Reducing reliance on traditional energy sources and lowering greenhouse gas emissions have significant environmental benefits.

[0044] Meanwhile, to reduce labor costs, automated control is achieved through the control unit: the control unit ensures that the waste heat from industrial exhaust gas is used efficiently and safely for agricultural applications through real-time monitoring and automatic adjustment, thereby improving energy efficiency and reducing production costs.

[0045] In the above description of specific embodiments of the present invention, features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments.

[0046] It should be emphasized that the term "including / comprises" as used herein refers to the presence of a feature, element, step, or component, but does not exclude the presence or addition of one or more other features, elements, steps, or components.

[0047] Although the present invention has been disclosed above through the description of specific embodiments, it should be understood that all the embodiments and examples described above are exemplary and not restrictive. Those skilled in the art can design various modifications, improvements, or equivalents to the present invention within the spirit and scope of the appended claims. These modifications, improvements, or equivalents should also be considered to be included within the protection scope of the present invention.

Claims

1. A waste heat recovery device based on industrial waste gas, characterized in that: include: The waste heat collection unit installed on the exhaust gas duct, the conveying duct connected to the waste heat collection unit, the underground heat exchange unit located at the end of the conveying duct, and the control unit for monitoring and automatic control. The control unit is installed on the conveying pipeline and includes a first regulating valve, a second regulating valve, a pressure transmitter, a pressure relief valve, a flow transmitter, a temperature acquisition device, a PLC controller, and a storage tank. The waste heat collection unit is divided into two paths: one path passes through the pressure transmitter, the pressure relief valve, the flow transmitter, and the second regulating valve in sequence, and finally connects to the conveying pipeline; the other path passes through the storage tank before connecting to the conveying pipeline. The first regulating valve is installed at the inlet end of the storage tank, and the outlet of the storage tank is connected to the flow transmitter. The storage tank has a placement port for the temperature acquisition device, and the output end of the temperature acquisition device is connected to the temperature transmitter. The output ends of the pressure transmitter, the flow transmitter, and the temperature transmitter are connected to the input end of the PLC controller, and the output end of the PLC controller is connected to the control end of the pressure relief valve and the second regulating valve.

2. The waste heat utilization device based on industrial waste gas according to claim 1, characterized in that: The waste heat collection unit is implemented using a heat exchanger.

3. The waste heat utilization device based on industrial waste gas according to claim 1, characterized in that: The delivery pipeline includes insulated pipes and a circulating pump.

4. The waste heat utilization device based on industrial waste gas according to claim 1, characterized in that: The underground heat exchange unit is a buried pipe heat exchanger or an injection heat exchange device.

5. The waste heat utilization device based on industrial waste gas according to claim 1, characterized in that: An exhaust gas treatment unit is also provided between the exhaust gas emission pipe and the waste heat collection unit. The exhaust gas treatment unit includes a filtration device and / or an adsorption device.

6. The waste heat utilization device based on industrial waste gas according to claim 5, characterized in that: The filtration device includes a pre-filter, a medium-efficiency filter, and a high-efficiency filter. The pre-filter is made of metal mesh or non-woven fabric; the medium-efficiency filter is made of non-woven fabric or filter paper; and the high-efficiency filter is made of HEPA filter.

7. The waste heat utilization device based on industrial waste gas according to claim 5, characterized in that: The adsorption device is an activated carbon adsorption device or a molecular sieve adsorption device.

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