Small-scale domestic waste clean heat treatment system and dynamic heat recovery method thereof

Abstract

The present invention provides a small-scale household garbage clean heat treatment system and a dynamic heat recovery method thereof, wherein the second-fuel flue gas discharged from the second-fuel reactor chamber is used to heat the first-fuel mixed combustion air entering the first-fuel reactor and the second-fuel mixed combustion air entering the second-fuel reactor through a heat regenerator, and the process parameters such as the temperature and flow rate of the first-fuel mixed combustion air and the second-fuel mixed combustion air are dynamically adjusted to optimize the reaction process in the first-fuel reactor and the second-fuel reactor. The small-scale household garbage clean heat treatment system and the dynamic heat recovery method thereof described in the present invention improve the adaptability range of the treatment system to the calorific value of garbage, optimize the reaction process of garbage in the first-fuel reactor and improve the quality of the first-fuel flue gas, and also optimize the reaction process of the first-fuel flue gas in the second-fuel reactor and improve the combustion efficiency and stability, reduce the comprehensive emission level of pollutants in the garbage heat treatment process and save flue gas costs, shorten the shutdown time, and better achieve the unity of economy and environmental protection.

Description

Technical Field

[0001] The present invention relates to the technical field of heat treatment of domestic waste, and in particular to a small-scale domestic waste clean heat treatment system and a dynamic heat recovery method thereof. Background Art

[0002] Proper treatment and disposal of domestic waste is an important part of ecological civilization construction and the promotion of sustainable social development. Thermal treatment is currently the most effective way to completely and quickly achieve the "three transformations" of domestic waste. It has the advantages of low comprehensive environmental costs and good comprehensive economic benefits. It has become the most important way to treat urban and rural domestic waste.

[0003] For domestic waste in villages and towns that is difficult to incinerate centrally, the use of small-scale clean thermal treatment systems for decentralized treatment has advantages and has become one of the development methods encouraged by the country.

[0004] The thermal treatment of domestic waste mainly includes direct combustion technology based on oxidation reaction mode, pyrolysis gasification based on pyrolysis reaction mode and then secondary combustion technology of pyrolysis products. For direct combustion, due to the high moisture content, low calorific value and low classification level of domestic waste in villages and towns, it is difficult to reach a sufficient reaction furnace temperature during the incineration process, resulting in a high concentration of pollutants in the flue gas and it is difficult to control, and it is difficult to stably meet the emission standards. Compared with direct combustion, pyrolysis gasification and secondary combustion of gasification products can greatly reduce the concentration of pollutants in the flue gas and the pollutants are relatively easy to control, which is more conducive to achieving standard flue gas emissions, or even ultra-low emissions, and has a good development prospect.

[0005] However, there are two core issues that need to be addressed in the technical route of pyrolysis and gasification of domestic waste and secondary combustion of gasification products: First, since the pyrolysis and gasification reaction is an endothermic reaction, how to obtain enough heat to maintain the pyrolysis and gasification reaction of domestic waste at a high level to produce pyrolysis gas with a sufficiently high calorific value; Second, how to maintain the high combustion efficiency and high combustion stability of the pyrolysis gas in the secondary combustion process, so that the substances in the pyrolysis gas can be fully decomposed into harmless substances.

[0006] To this end, reference document ZL202210177504.5 (CN 114484448 A) proposes a small-scale clean incineration system for domestic waste and its energy balance method, which realizes the energy balance of the reaction of the waste in the pyrolysis furnace by oxidizing the residue after the waste is pyrolyzed to a certain depth to release heat, and combines the high-temperature flue gas generated by the secondary combustion of the pyrolysis gas to the pyrolysis furnace (one combustion reactor) for heat recovery, thereby achieving the purpose of smoothly and steadily pyrolyzing the domestic waste in the furnace without the need for external auxiliary energy input, and forming pyrolysis gas (one combustion flue gas) with combustibility; at the same time, by heat recovery from the high-temperature flue gas to the secondary combustion chamber (two combustion reactor), the combustion efficiency and combustion stability of the pyrolysis gas in the two combustion reactor are improved. As a result, the incineration system has a good adaptability to domestic waste, while reducing the concentration of harmful substances in the flue gas, reducing the difficulty and cost of flue gas treatment, and realizing the unity of economy and environmental protection in the waste treatment process.

[0007] Generally speaking, during the pyrolysis-combustion coupling reaction of domestic waste in the primary combustion reactor and the combustion reaction of the primary combustion flue gas in the secondary combustion reactor, the temperature and flow rate of the co-combustion air are two very important and mutually coupled process parameters. The temperature reflects the specific enthalpy of the co-combustion air, and the flow rate reflects the sufficiency of the oxidation reaction (the pyrolysis depth of the waste in the primary combustion reactor). The product of the specific enthalpy and the flow rate is the heat recovery. In the primary combustion reactor, the process parameters of the primary combustion air have a very important influence on the composition, calorific value, flow rate and flammability of the primary combustion flue gas. In the secondary combustion reactor, the process parameters of the secondary combustion air are also crucial to the combustion efficiency and combustion stability, that is, they have a significant impact on the concentration of harmful substances in the secondary combustion flue gas. Therefore, for small-scale domestic waste clean heat treatment systems, it is of great significance to achieve dynamic and precise control of process parameters such as the flow rate and temperature of the primary combustion air and the secondary combustion air.

[0008] However, practice has shown that the small-scale clean incineration system of domestic waste and its energy balance method proposed in reference ZL202210177504.5 have four shortcomings because it is difficult to dynamically and accurately adjust the process parameters such as the temperature, flow rate and heat recovery of the co-combustion air entering each level of reactor: First, since all the co-combustion air entering a combustion furnace must be reheated, the shutdown process is very slow. For the system that only runs one shift a day, the time required to reduce the furnace temperature to a safe temperature is too long, which increases the working hours of the operators; second, when the calorific value of the garbage is high, continuous and large-scale heat recovery can easily lead to overheating of the reaction chamber, affecting The first layout limits the heat recovery capacity of the secondary flue gas to the primary reactor, resulting in a narrower adaptability range for low calorific value garbage; the second layout is that the flow rate and temperature of the co-combustion air entering the primary reactor cannot be dynamically and accurately controlled, which is not conducive to the reaction process and state control of the garbage in the primary reactor. When the flow rate, calorific value and other parameters of the primary flue gas flue fluctuate, it is difficult to control in time, resulting in the operating stability and comprehensive combustion efficiency of the secondary reactor to be further improved.

[0009] Therefore, based on the optimization control of the operation process of a small-scale clean heat treatment system for domestic waste, a dynamic heat recovery method for a small-scale clean heat treatment system for domestic waste was developed, and a control strategy for process parameters was proposed. It can dynamically and accurately control the heat recovery amount and process parameters of the primary combustion reactor and the secondary combustion reactor, which is of great significance to the development of small-scale clean heat treatment equipment for domestic waste and the development of decentralized domestic waste treatment technology. Summary of the invention

[0010] The present invention is a further optimization and improvement based on patent ZL202210177504.5, providing a small-scale domestic waste clean heat treatment system and a dynamic heat recovery method thereof, which solves the problem that the process parameters of the reaction process in the existing technology are difficult to dynamically and accurately control during operation of the waste clean heat treatment system. The technical solution of the present invention is as follows:

[0011] A dynamic heat recovery method for a small-scale domestic waste clean heat treatment system:

[0012] The domestic garbage is combined with the first combustion air in the first combustion reactor to produce a self-adaptive pyrolysis-combustion coupling reaction, generating first combustion flue gas containing organic combustible components and having a certain calorific value;

[0013] The primary flue gas and secondary combustion air are simultaneously introduced into the secondary combustion reactor for oxidation reaction, and the organic combustible components in the primary flue gas are oxidized and decomposed in the secondary combustion reactor, and the heat released increases the temperature of the flue gas to form high-temperature secondary combustion flue gas;

[0014] The secondary combustion flue gas flows through the primary combustion regenerator and the secondary combustion regenerator in sequence, respectively heating the primary combustion regenerated cold air and the secondary combustion regenerated cold air to generate primary combustion regenerated hot air and secondary combustion regenerated hot air;

[0015] The process parameters such as the temperature and flow rate of the air mixed with the first fuel are obtained by dynamically mixing the hot air recovered from the first fuel with the cold air directly supplied from the first fuel according to the needs of optimizing the reaction process of the first fuel reactor;

[0016] The process parameters of the secondary combustion air, such as temperature and flow rate, are obtained by dynamically mixing the secondary combustion hot air with the secondary combustion direct supply cold air according to the need for real-time control of the thermal parameters of the secondary combustion flue gas;

[0017] Thereby, the small-scale domestic waste clean heat treatment system is in an ideal operating state.

[0018] The present invention proposes a dynamic heat recovery method for a small-scale domestic waste clean heat treatment system, which includes the following specific implementation steps:

[0019] (1) Flue gas generation:

[0020] After the garbage is preheated, heated, and dried in the one-combustion reactor, it further absorbs heat and undergoes a pyrolysis reaction to generate pyrolysis gas containing organic combustible components. The residue after the garbage is pyrolyzed to a certain depth undergoes an oxidation (combustion) reaction with the one-combustion mixed air introduced into the one-combustion reactor, releasing heat and generating CO. 2 , H 2 Gases containing components such as O and CO.

[0021] The heat released by the oxidation reaction of the garbage pyrolysis residue and the energy brought by the combustion air of the first combustion reactor are used as the heat required for the garbage pyrolysis reaction. The reaction of garbage in the first combustion reactor is an adaptive pyrolysis-combustion coupling reaction based on the oxygen input.

[0022] The mixed flue gas produced by various reactions in the single-combustion reactor is single-combustion flue gas.

[0023] As the pyrolysis-combustion coupling reaction proceeds in the first-fuel reactor, the flow rate, temperature and other process parameters of the first-fuel mixed combustion air are adjusted timely and dynamically to make the calorific value and calorific value stability of the first-fuel flue gas as close to the target value as possible.

[0024] (2) Preparation of combustion air:

[0025] The high-temperature secondary combustion flue gas discharged from the secondary combustion reactor first flows into the primary combustion regenerator to heat the primary combustion regenerated cold air to become primary combustion regenerated hot air; then the primary combustion regenerated hot air is mixed with the primary combustion direct supply cold air to obtain primary combustion mixed air that meets the requirements.

[0026] Combined with the calorific value, composition and other physical parameters of the garbage, a functional relationship matrix (equation group) between the calorific value, flow rate, temperature of the flue gas and the temperature and flow rate of the fuel-blended combustion air is constructed, and the deviation between the theoretical calorific value of the flue gas and the target calorific value is minimized as the optimization goal, and the target process parameters such as the flow rate and temperature of the fuel-blended combustion air are obtained, and this is used as the basis for dynamic control of the process parameters of the fuel-blended combustion air;

[0027] The flow rate of the first fuel mixed combustion air is equal to the sum of the flow rates of the first fuel return heat hot air and the first fuel direct supply cold air;

[0028] The temperature of the air mixed with the first fuel depends on the temperature of the hot air returned by the first fuel, the temperature of the cold air directly supplied by the first fuel, and the mixing ratio of the two.

[0029] (3) Generation of secondary combustion flue gas:

[0030] The first fuel flue gas is introduced into the second fuel reactor, and the second fuel mixed air is introduced into the second fuel reactor at the same time. The first fuel flue gas and the second fuel mixed air undergo an oxidation reaction to release heat, forming high-temperature second fuel flue gas and discharging it from the second fuel reactor, and flowing through the first fuel reheater and the second fuel reheater in sequence.

[0031] The temperature and oxygen concentration of the secondary combustion flue gas are used as reaction indicators of the combustion efficiency of the secondary combustion reactor and the concentration of harmful substances in the flue gas.

[0032] (4) Preparation of secondary combustion air:

[0033] After the secondary fuel flue gas flows out of the primary fuel regenerator, it flows into the secondary fuel regenerator to heat the secondary fuel regenerated cold air to obtain secondary fuel regenerated hot air, and the secondary fuel regenerated hot air is mixed with the secondary fuel directly supplied cold air to obtain secondary fuel mixed combustion air that meets the requirements;

[0034] The oxygen concentration target range and temperature target range in the secondary combustion flue gas are the control basis for target process parameters such as flow rate and temperature of the secondary combustion air respectively;

[0035] The flow rate of the secondary fuel mixed combustion air depends on the sum of the flow rates of the secondary fuel reheated hot air and the secondary fuel directly supplied cold air;

[0036] The temperature of the secondary fuel mixed combustion air depends on the temperature of the secondary fuel reheated hot air, the temperature of the secondary fuel directly supplied cold air, and the mixing ratio of the two.

[0037] The structure of the small-scale domestic waste clean heat treatment system of the present invention is used to implement the dynamic heat recovery method of the small-scale domestic waste clean heat treatment system, including a primary combustion reactor, a secondary combustion reactor, a primary combustion heat regenerator, a secondary combustion heat regenerator, and also includes:

[0038] A flue gas pipe, one end of which is connected to the outlet of the first combustion reactor, and the other end of which is connected to the inlet of the second combustion reactor;

[0039] A fuel direct supply pipe and a fuel heat recovery pipe are arranged in parallel, and a fuel direct supply valve and a fuel heat recovery valve are respectively provided on the fuel direct supply pipe and the fuel heat recovery pipe. The fuel heat recovery pipe is connected to the air side inlet of the fuel heat recovery device downstream of the fuel heat recovery valve. The fuel direct supply pipe is downstream of the fuel direct supply valve and merges with the fuel heat recovery pipe downstream of the fuel heat recovery device into one end of a fuel intake pipe. The other end of the fuel intake pipe is connected to a fuel reactor.

[0040] A two-fuel direct supply pipe and a two-fuel heat recovery pipe are arranged in parallel, and the two-fuel direct supply pipe and the two-fuel heat recovery pipe are respectively provided with a two-fuel direct supply valve and a two-fuel heat recovery valve, and the two-fuel heat recovery pipe is connected to the air side inlet of the two-fuel heat recovery device downstream of the two-fuel heat recovery valve, and the two-fuel direct supply pipe is downstream of the two-fuel direct supply valve, and together with the two-fuel heat recovery pipe downstream of the two-fuel heat recovery device, it merges into one end of the two-fuel air intake pipe, and the other end of the two-fuel air intake pipe is connected to the two-fuel reactor;

[0041] A secondary fuel flue gas pipe, one end of which is connected to the outlet of the secondary fuel reactor, and the other end is connected to the flue gas inlet of the primary fuel regenerator;

[0042] A regenerator connecting pipe, one end of which is connected to the flue gas outlet of the first-burning regenerator, and the other end of which is connected to the flue gas inlet of the second-burning regenerator;

[0043] A flue gas down pipe, one end of which is connected to the outlet of the flue gas side of the secondary combustion heat regenerator, and the other end is connected to the downstream.

[0044] Preferably, the air inlet ends of the first fuel direct supply pipe, the first fuel heat recovery pipe, the second fuel direct supply pipe, and the second fuel heat recovery pipe are respectively connected to the outlets of the first fuel direct supply fan, the first fuel heat recovery fan, the second fuel direct supply fan, and the second fuel heat recovery fan;

[0045] Preferably, the first fuel direct supply pipe and the first fuel heat recovery pipe are connected to the outlet of the first fuel blower, and the second fuel direct supply pipe and the second fuel heat recovery pipe are connected to the outlet of the second fuel blower;

[0046] Preferably, the above-mentioned flue gas pipe is provided with a flue gas temperature sensor, a flue gas dynamic pressure sensor, and a flue gas oxygen concentration sensor;

[0047] Preferably, the fuel intake pipe is provided with at least one fuel intake air temperature sensor and one fuel intake air dynamic pressure sensor;

[0048] Preferably, a secondary fuel intake air temperature sensor is provided on the secondary fuel intake pipe;

[0049] Preferably, a secondary fuel smoke temperature sensor is provided on the secondary fuel smoke pipe, and a secondary fuel smoke oxygen concentration sensor is provided on the smoke down pipe;

[0050] Preferably, the first fuel direct supply valve, the first fuel heat recovery valve, the second fuel direct supply valve, and the second fuel heat recovery valve are all proportional control valves.

[0051] With the above structure, the dynamic heat recovery method of the small-scale domestic waste clean heat treatment system, the adjustment method of the temperature, flow rate and other process parameters of the primary fuel mixed combustion air and the secondary fuel mixed combustion air is:

[0052] (1) Combustion air:

[0053] The temperature of the fuel-combustion air is monitored in real time by a fuel intake air temperature sensor;

[0054] When it is necessary to adjust the temperature of the fuel-blended air: increase the opening of the fuel direct supply valve and decrease the opening of the fuel heat recovery valve to lower the temperature of the fuel-blended air, until the fuel direct supply valve is fully opened and the fuel heat recovery valve is fully closed, at which time the temperature of the fuel-blended air is the atmospheric environment temperature; conversely, reduce the opening of the fuel direct supply valve and increase the opening of the fuel heat recovery valve to increase the temperature of the fuel-blended air, until the fuel direct supply valve is fully closed and the fuel heat recovery valve is fully opened, at which time the temperature of the fuel-blended air is the maximum heat recovery temperature.

[0055] The flow rate of the fuel-blended air is indirectly displayed by a fuel intake air dynamic pressure sensor arranged on the fuel air pipe. The principle is: the dynamic pressure is equal to the difference between the total pressure and the static pressure. The flow velocity is obtained from the dynamic pressure, and the flow rate can be obtained according to the cross-sectional area of ​​the pipeline.

[0056] When the flow rate of the fuel-blended air needs to be adjusted: the opening of the fuel direct supply valve and the fuel heat recovery valve is increased or decreased simultaneously to increase or decrease the flow rate of the fuel-blended air; when the fuel direct supply valve and the fuel heat recovery valve are all closed, the fuel-blended air is cut off.

[0057] (2) Secondary combustion air

[0058] The temperature of the secondary fuel blended air is monitored in real time by a secondary fuel intake air temperature sensor disposed on the secondary fuel air pipe.

[0059] The adjustment method of the temperature and flow rate of the second fuel mixed combustion air is similar to that of the first fuel mixed combustion air.

[0060] When it is necessary to adjust the temperature of the air blended with the second fuel: increase the opening of the second fuel direct supply valve and decrease the opening of the second fuel heat recovery valve, so as to lower the temperature of the air blended with the second fuel, until the second fuel direct supply valve is fully opened and the second fuel heat recovery valve is fully closed, at which time the temperature of the air blended with the second fuel is the atmospheric environment temperature; conversely, reduce the opening of the second fuel direct supply valve and increase the opening of the second fuel heat recovery valve, so as to increase the temperature of the air blended with the second fuel, until the second fuel direct supply valve is fully closed and the second fuel heat recovery valve is fully opened, at which time the temperature of the air blended with the second fuel is the maximum heat recovery temperature.

[0061] When the flow rate of the secondary fuel blended air needs to be adjusted, the secondary fuel direct supply valve and the secondary fuel regenerative valve are simultaneously increased or decreased in opening, so as to increase or decrease the flow rate of the secondary fuel blended air. When the secondary fuel direct supply valve and the secondary fuel regenerative valve are all closed, the secondary fuel blended air is cut off.

[0062] With the above structure, the control strategy and logic of the process parameters such as the temperature and flow rate of the primary fuel mixed with air and the secondary fuel mixed with air are as follows:

[0063] Step 1: Heat the furnace

[0064] The first fuel reactor ignition system starts to operate; the first fuel mixed combustion air is all the first fuel return hot air, that is, the first fuel direct supply valve is closed; the second fuel mixed combustion air is cut off;

[0065] When the temperature of the first combustion flue gas reaches a first set value, the first combustion reactor ignition system stops operating;

[0066] When the temperature of the first fuel flue gas reaches the second set value, the flow rate of the first fuel mixed combustion air is gradually reduced until the oxygen concentration in the first fuel flue gas is reduced to zero, and then the second fuel regenerative valve is gradually opened, and the ignition system of the second fuel reactor starts to operate;

[0067] When the temperature of the secondary combustion flue gas reaches a set value within a set time, the secondary combustion reactor ignition system stops running and goes to the second step;

[0068] When the temperature of the secondary combustion flue gas does not reach the set value within the set time, the secondary combustion reactor ignition system stops running and goes to the seventh step.

[0069] Step 2: Determine the working status of the first combustion reactor and the second combustion reactor

[0070] Read the monitoring data of the primary flue gas temperature sensor, the secondary flue gas dynamic pressure sensor, the secondary flue gas oxygen concentration sensor, and the secondary flue gas temperature sensor and the secondary flue gas oxygen concentration sensor to determine:

[0071] If the oxygen concentration in the first fuel flue gas is greater than zero, the pyrolysis reaction in the first fuel reactor has not occurred or has been interrupted, and an oxidation combustion reaction is taking place. Cut off the second fuel co-combustion air, and at the same time, all the first fuel co-combustion air is the first fuel reheating hot air, and the first fuel reheating valve is adjusted to the maximum, and then the first fuel reheating valve is gradually adjusted down, the temperature is adjusted to the highest, and the flow rate of the first fuel co-combustion air is gradually reduced, and then go to the first step;

[0072] If the oxygen concentration of the first combustion flue gas is equal to zero, the temperature of the first combustion flue gas is compared with the temperature of the second combustion flue gas:

[0073] When the temperature of the primary combustion flue gas is lower than the temperature of the secondary combustion flue gas, the secondary combustion reactor is in operation, and the process proceeds to the third step;

[0074] When the temperature of the first-combustion flue gas is greater than or equal to the temperature of the second-combustion flue gas, the second-combustion reactor is in a state of unsuccessful startup or extinguished, the ignition system of the second-combustion reactor is started, and timing begins: if the temperature of the first-combustion flue gas is less than the temperature of the second-combustion flue gas within the set time, that is, the ignition is successful, the ignition system of the second-combustion reactor is turned off, and the third step is turned on; if the temperature of the first-combustion flue gas is still greater than or equal to the temperature of the second-combustion flue gas within the set time, the ignition system of the second-combustion reactor is turned off, and the fourth step is turned on;

[0075] Step 3: Optimize and adjust the secondary combustion air parameters

[0076] Read the monitoring data of the secondary combustion flue gas temperature sensor and secondary combustion flue gas oxygen concentration sensor to determine:

[0077] When the oxygen concentration in the secondary combustion flue gas is lower than a set lower limit, increasing the flow rate of the secondary combustion air;

[0078] When the oxygen concentration in the secondary combustion flue gas is higher than the set upper limit, the flow rate of the secondary combustion air is reduced;

[0079] When the temperature of the secondary combustion flue gas is lower than the set lower limit, the temperature of the secondary combustion air is increased and its flow rate is reduced to adjust the oxygen concentration in the secondary combustion flue gas to the lower limit within the allowable range;

[0080] When the temperature of the secondary combustion flue gas is higher than the set upper limit, the temperature of the secondary combustion air is reduced and its flow rate is increased to adjust the oxygen concentration in the secondary combustion flue gas to the upper limit within the allowable range.

[0081] Step 4: Obtain the theoretical calorific value of the flue gas and the deviation between the theoretical calorific value and the target value

[0082] Combined with the current calorific value and composition of the garbage, as well as the data of each data monitoring point such as the primary combustion air, primary combustion flue gas, secondary combustion flue gas, and secondary combustion air, the theoretical calorific value of the primary combustion flue gas is obtained according to the principle of conservation of energy;

[0083] The theoretical calorific value of the flue gas is compared with a set target value to obtain a deviation between the theoretical calorific value of the flue gas and the target value.

[0084] Step 5: Obtain the correction value of the fuel-air blending process parameter

[0085] With the goal of minimizing the deviation between the theoretical calorific value of the flue gas and the target calorific value, combined with specific domestic waste parameters, the set value range of the fuel-combined combustion air is used as the decision variable, and the functional relationship between the calorific value of the flue gas and the fuel-combined combustion air parameters is used as the constraint condition to construct an optimization plan, and the optimal solution for the corrected values ​​of process parameters such as temperature and flow rate of the fuel-combined combustion air is obtained.

[0086] Step 6: Optimize and adjust the process parameters of fuel-air mixing

[0087] According to the optimal solution of the correction values ​​of the process parameters such as the temperature and flow rate of the first fuel-compounded combustion air, the process parameters of the first fuel-compounded combustion air are adjusted:

[0088] Adjusting the temperature parameter of the first fuel blended combustion air;

[0089] Adjusting the flow parameters of the first fuel blended combustion air;

[0090] Go to the second step;

[0091] Step 7: The single combustion reactor enters direct combustion mode

[0092] Read the oxygen concentration, temperature, flow rate and other parameters of the first fuel flue gas, adjust the parameters of the first fuel mixed with air, and ensure that the oxygen concentration and temperature in the first fuel flue gas are between the set upper and lower limits respectively:

[0093] When the oxygen concentration in the first fuel flue gas is less than the set lower limit, increasing the flow rate of the first fuel blended with the combustion air;

[0094] When the oxygen concentration in the first fuel flue gas is greater than a set upper limit, reducing the flow rate of the first fuel combustion air;

[0095] When the temperature of the first combustion flue gas is lower than the set lower limit, increasing the temperature of the first combustion air;

[0096] When the temperature of the first combustion flue gas is greater than the set upper limit value, the temperature of the first combustion air is reduced.

[0097] If the temperature of the first fuel mixed air reaches the set upper limit value, it is still not possible to ensure that the temperature of the first fuel flue gas is increased to or above the set lower limit value, go to step 8;

[0098] If the temperature of the first fuel mixed combustion air reaches the set lower limit value, it is still impossible to ensure that the temperature of the first fuel flue gas drops to the set upper limit value or below, the first fuel mixed combustion air is cut off and the process goes to the second step.

[0099] Step 8: Shutdown Mode

[0100] The heat recovery of the first fuel mixed combustion air and the second fuel mixed combustion air is cancelled, that is, the first fuel mixed combustion air is all the first fuel direct supply cold air, and the second fuel mixed combustion air is all the second fuel direct supply cold air, until the temperature of the first fuel flue gas drops below the set value and the oxygen concentration increases to above the set value, and can be maintained for the set time;

[0101] Then cut off the combustion air of the first fuel and the second fuel, and shut down the machine.

[0102] Thus, the small-scale domestic waste clean heat treatment system can achieve dynamic and precise control of the process parameters such as the first fuel mixed combustion with air and the second fuel mixed combustion with air in different operation stages, so that the coupled reaction of the garbage in the first fuel reactor generates high-quality first fuel flue gas, and the first fuel flue gas undergoes efficient and stable oxidation reaction in the second fuel reactor, thereby achieving the unity of economy and environmental protection in the process of harmless treatment of domestic waste. In addition, when the calorific value of the garbage is too low to be pyrolyzed, the direct combustion mode is adopted to reduce the emission of harmful pollutants; when the furnace needs to be stopped, the heat recovery mode is cancelled to accelerate the reduction of the furnace temperature and save the shutdown time.

[0103] The above technical solution of the present invention includes at least the following beneficial effects:

[0104] (1) The dynamic heat recovery method of the small-scale domestic waste clean heat treatment system of the present invention heats the primary combustion air and the secondary combustion air respectively through the secondary combustion flue gas, dynamically, on demand, and accurately controls the process parameters of the primary combustion reactor and the secondary combustion reactor, thereby making the system more adaptable to waste, and improving the combustion efficiency and combustion stability of the secondary combustion reactor, reducing the concentration of harmful substances in the flue gas, and reducing the difficulty and cost of flue gas treatment. Specifically:

[0105] First, the precise control of the process parameters such as the temperature and flow rate of the air mixed with the first combustion can further optimize the energy balance relationship when the garbage undergoes adaptive pyrolysis-combustion reaction in the first combustion reactor, improve the pyrolysis reaction depth of the garbage, optimize the reaction process, and increase the calorific value and calorific value stability of the first combustion flue gas;

[0106] Second, while increasing the calorific value and calorific value stability of the primary flue gas, the temperature, flow rate and other process parameters of the secondary combustion air are precisely controlled, thereby improving the operating conditions of the secondary combustion reactor, making the secondary combustion reactor more efficient, more stable, and with a wider working threshold, which is more conducive to the rapid, full and thorough oxidation and decomposition of organic pollutants in the primary flue gas, thereby reducing the difficulty of purifying the high-temperature flue gas and better ensuring that the exhaust flue gas meets the emission standards.

[0107] (2) The small-scale clean heat treatment system for domestic waste of the present invention can realize independent management and dynamic adjustment of strongly coupled process parameters such as temperature and flow rate of each combustion air through the comprehensive design of structures such as fans, pipelines, and valves, thereby overcoming the engineering implementation problems of mutual interference between process parameters and difficulty in accurate and timely control.

[0108] (3) Since the reaction mode of the one-combustion reactor can be flexibly switched between the adaptive pyrolysis-combustion coupling reaction mode and the direct combustion reaction mode as needed, the function of the one-combustion regenerator can be flexibly cut off, which greatly shortens the shutdown time of the one-combustion reactor and reduces the working hours and energy consumption of the operators.

[0109] This makes the small-scale domestic waste clean thermal treatment system have better performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0110] Figure 1 1 is a schematic structural diagram of a small-scale domestic waste clean heat treatment system according to Example 1 of the present invention;

[0111] Figure 2 is a schematic structural diagram of a small-scale domestic waste clean heat treatment system according to Example 2 of the present invention;

[0112] Among them, 1. One fuel reactor; 2. One fuel air intake pipe; 3. One fuel direct supply fan; 4. One fuel heat recovery fan; 5. Heat recovery device connecting pipe; 6. Two fuel direct supply fan; 7. Two fuel heat recovery fan; 8. Flue gas down pipe; 9. Two fuel heat recovery device; 10. Two fuel air intake pipe; 11. One fuel heat recovery device; 12. Two fuel smoke pipe; 13. Two fuel reactor; 14. One fuel smoke pipe; 15. One fuel fan; 16. Two fuel fans; 021. One fuel air intake temperature sensor; 022. One fuel air intake dynamic pressure sensor; 023. One fuel mixed combustion air; 031. One fuel direct supply valve; 032. One fuel direct supply pipe; 033. One fuel direct supply air; 041. One fuel heat recovery valve; 042. One fuel heat recovery pipe; 043, one fuel heat recovery cold air; 044, one fuel heat recovery hot air; 061, two fuel direct supply valve; 062, two fuel direct supply pipe; 063, two fuel direct supply cold air; 071, two fuel heat recovery valve; 072, two fuel heat recovery pipe; 073, two fuel heat recovery cold air; 074 two fuel heat recovery hot air; 101, two fuel intake air temperature sensor; 102, two fuel intake air static pressure sensor; 103, two fuel blending air; 121, two fuel flue gas; 122, two fuel flue gas temperature sensor; 123, two fuel flue gas oxygen concentration sensor; 141, one fuel flue gas temperature sensor; 142, one fuel flue gas dynamic pressure sensor; 143, one fuel flue gas oxygen concentration sensor. DETAILED DESCRIPTION

[0113] Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present invention can be implemented in other suitable forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0114] Example 1

[0115] like Figure 1 As shown, the embodiment of the present invention proposes a structure of a small-scale household waste clean heat treatment system, including a primary combustion reactor 1, a secondary combustion reactor 13, a primary combustion regenerator 11, and a secondary combustion regenerator 9; and also includes:

[0116] A flue gas pipe 14, one end of which is connected to the flue gas outlet of the first combustion reactor 1, and the other end of which is connected to the fuel inlet of the second combustion reactor 13; a flue gas temperature sensor 142, a flue gas dynamic pressure sensor 143, and a flue gas oxygen concentration sensor 144 are provided on the flue gas pipe 14;

[0117] A fuel direct supply fan 3 and a fuel heat recovery fan 4 are arranged in parallel, the outlet of the fuel direct supply fan 3 is connected to a fuel direct supply pipe 032, and the fuel direct supply pipe 032 is provided with a fuel direct supply valve 031 with proportionally adjustable opening; the outlet of the fuel heat recovery fan 4 is connected to a fuel heat recovery pipe 042, and the fuel heat recovery pipe 042 is provided with a fuel heat recovery valve 041 with proportionally adjustable opening, and is connected to the air side of a fuel heat recovery device 11 downstream of the fuel heat recovery valve 041; the fuel direct supply pipe 032 merges with the fuel heat recovery pipe 042 at one end of a fuel intake pipe 2 downstream of the fuel direct supply valve 031 and after the air side outlet of the fuel heat recovery device 11, and the other end of the fuel intake pipe 2 is connected to a fuel reactor 1; the fuel intake pipe 2 is provided with a fuel intake air temperature sensor 021 and a fuel intake air dynamic pressure sensor 022;

[0118] A two-fuel direct supply fan 6 and a two-fuel heat recovery fan 7 are arranged in parallel, the outlet of the two-fuel direct supply fan 6 is connected to a two-fuel direct supply pipe 062, and the two-fuel direct supply pipe 062 is provided with a two-fuel direct supply valve 061 with a proportional adjustment of the opening; the outlet of the two-fuel heat recovery fan 7 is connected to a two-fuel heat recovery pipe 072, and the two-fuel heat recovery pipe 072 is provided with a two-fuel heat recovery valve 071 with a proportional adjustment of the opening, and is connected to the air side of the two-fuel heat recovery device 9 downstream of the two-fuel heat recovery valve 071; the two-fuel direct supply pipe 062 and the two-fuel heat recovery pipe 072 are connected to one end of the two-fuel air intake pipe 10 downstream of the two-fuel direct supply valve 061 and after the air side outlet of the two-fuel heat recovery device 9, and the other end of the two-fuel air intake pipe 10 is connected to the two-fuel reactor 13; the two-fuel air intake pipe 10 is provided with a two-fuel air intake temperature sensor 101;

[0119] A secondary fuel smoke pipe 12, one end of which is connected to the outlet of the secondary fuel reactor 13, and the other end is connected to the smoke inlet of the primary fuel regenerator 11; a secondary fuel smoke temperature sensor 122 is provided on the secondary fuel smoke pipe 12;

[0120] The regenerator connecting pipe 5 has one end connected to the flue gas outlet of the first-fuel regenerator 11, and the other end connected to the flue gas inlet of the second-fuel regenerator 9; that is, the first-fuel regenerator 11 and the second-fuel regenerator 9 are connected in series through the regenerator connecting pipe 5;

[0121] The flue gas downward pipe 8 has one end connected to the outlet of the secondary combustion heat regenerator 9 on the flue gas side, and the other end connected to the downstream heat recovery or flue gas purification unit; the flue gas downward pipe 8 is provided with a secondary combustion flue gas oxygen concentration sensor 123.

[0122] The working process of the small-scale domestic waste clean heat treatment system of this embodiment is as follows:

[0123] When the small-scale domestic waste clean heat treatment system is in operation, the waste undergoes an adaptive pyrolysis-combustion coupling reaction in the primary combustion reactor 1, and generates a primary combustion flue gas 141 containing organic combustible components and having a certain calorific value and temperature. The primary combustion flue gas 141 is transported to the secondary combustion reactor 13 through the primary combustion flue gas pipe 14, and the primary combustion flue gas 143 undergoes an oxidation reaction in the secondary combustion reactor 13, the reaction releases heat and generates secondary combustion flue gas 121, and the secondary combustion flue gas 121 flows through the secondary combustion flue gas pipe 12 in sequence through the primary combustion regenerator 11, the regenerator connecting pipe 5, and the secondary combustion regenerator 9, and is finally sent to the downstream through the flue gas down-feeding pipe 8;

[0124] When the secondary combustion flue gas 121 flows through a combustion regenerator 11, it exchanges heat with a combustion reheat cold air 043 from a combustion reheat fan 4 and a combustion reheat pipe 042, and heats the combustion reheat cold air 043 to become combustion reheat hot air 044; the combustion reheat hot air 044 and a combustion direct supply cold air 033 from a combustion direct supply fan 3 and a combustion direct supply air pipe 032 enter a combustion blending air pipe 2 together to form a combustion blending air 023, and the combustion blending air 023 enters a combustion reactor 1 through a combustion blending air pipe 2 to maintain and optimize the reaction of the garbage in the combustion reactor 1;

[0125] When the secondary fuel flue gas 121 flows through the secondary fuel reheater 9, it exchanges heat with the secondary fuel reheating cold air 073 from the secondary fuel reheating fan 7 and the secondary fuel reheating pipe 072, and heats the secondary fuel reheating cold air 073 to become secondary fuel reheating hot air 074; the secondary fuel reheating hot air 074 enters the secondary fuel blending air pipe 10 together with the secondary fuel direct supply cold air 063 from the secondary fuel direct supply fan 6 and the secondary fuel direct supply air pipe 062 to form the secondary fuel blending air 102, and the secondary fuel blending air 102 enters the secondary fuel reactor 13 through the secondary fuel blending air pipe 10 to maintain and optimize the oxidation reaction of the primary fuel flue gas 141 in the secondary fuel reactor 13.

[0126] The principle of the dynamic heat recovery method of the small-scale domestic waste clean heat treatment system in this embodiment is as follows:

[0127] The real-time temperature and flow data of a fuel blending air 023 are monitored by a fuel blending air temperature sensor 021 and a fuel blending air dynamic pressure sensor 022 respectively;

[0128] The real-time temperature, flow rate and oxygen concentration data of a flue gas 141 are respectively monitored by a flue gas temperature sensor 142, a flue gas dynamic pressure sensor 143 and a flue gas oxygen concentration sensor;

[0129] The real-time temperature and oxygen concentration data of the secondary combustion flue gas 121 are respectively monitored by the secondary combustion flue gas temperature sensor 122 and the secondary combustion flue gas oxygen concentration sensor 081;

[0130] The real-time temperature data of the secondary fuel blended air 102 is monitored by the secondary fuel blended air temperature sensor 101 .

[0131] When it is necessary to increase the temperature of the fuel-blended combustion air 023, the temperature can be increased by increasing the opening of the fuel heat recovery valve 041 and decreasing the opening of the fuel direct supply valve 031, thereby increasing the flow of the fuel heat recovery hot air 044 and decreasing the flow of the fuel direct supply cold air 033; conversely, when it is necessary to reduce the temperature of the fuel-blended combustion air 023, the temperature can be reduced by decreasing the opening of the fuel heat recovery valve 041 and increasing the opening of the fuel direct supply valve 031, thereby decreasing the flow of the fuel heat recovery hot air 044 and increasing the flow of the fuel direct supply cold air 033;

[0132] When the flow rate of the fuel-blended combustion air 023 needs to be increased, the flow rate of the fuel-blended combustion air 023 can be increased by simultaneously increasing the opening of the fuel-regenerating valve 041 and the fuel-direct supply valve 031, thereby simultaneously increasing the flow rates of the fuel-regenerating hot air 044 and the fuel-direct supply cold air 033; conversely, when the flow rate of the fuel-blended combustion air 023 needs to be reduced, the flow rate of the fuel-blended combustion air 023 can be reduced by simultaneously reducing the opening of the fuel-regenerating valve 041 and the fuel-direct supply valve 031, thereby simultaneously reducing the flow rates of the fuel-regenerating hot air 044 and the fuel-direct supply cold air 033;

[0133] Similarly,

[0134] When the temperature of the second fuel mixed combustion air 102 needs to be increased, the flow rate of the second fuel heat recovery hot air 074 is increased and the flow rate of the second fuel direct supply cold air 063 is reduced by increasing the opening of the second fuel heat recovery valve 071 and reducing the opening of the second fuel direct supply valve 061 to achieve the desired effect; conversely, when the temperature of the second fuel mixed combustion air 102 needs to be reduced, the flow rate of the first fuel heat recovery hot air 074 is reduced and the flow rate of the first fuel direct supply cold air 063 is increased by reducing the opening of the second fuel heat recovery valve 071 and increasing the opening of the second fuel direct supply valve 061 to achieve the desired effect;

[0135] When it is necessary to increase the flow rate of the secondary fuel blended air 102, this can be achieved by simultaneously increasing the opening of the secondary fuel heat recovery valve 071 and the secondary fuel direct supply valve 061, thereby increasing the flow rates of the secondary fuel heat recovery hot air 074 and the secondary fuel direct supply cold air 063; conversely, when it is necessary to reduce the flow rate of the secondary fuel blended air 102, this can be achieved by simultaneously reducing the opening of the secondary fuel heat recovery valve 071 and the secondary fuel direct supply valve 061, thereby reducing the flow rates of the secondary fuel heat recovery hot air 074 and the secondary fuel direct supply cold air 063.

[0136] The process parameter control strategy and logic of the dynamic heat recovery method of the small-scale domestic waste clean heat treatment system of the embodiment are as follows:

[0137] Step 1: Heat the furnace

[0138] The ignition system of the first fuel reactor 1 starts to operate, the first fuel mixed combustion air 023 is all the first fuel reheat hot air 044, the first fuel direct supply valve 031, the second fuel direct supply valve 061, and the second fuel reheat valve are all closed;

[0139] When the temperature of the combustion flue gas 141 reaches a first set value (e.g., 280° C.), the ignition system of the combustion reactor 1 stops operating;

[0140] When the temperature of the primary combustion flue gas 141 reaches the second set value (e.g., 350° C.), the flow rate of the primary combustion air 141 is gradually reduced until the oxygen concentration in the primary combustion flue gas 141 is reduced to zero, and then the secondary combustion regenerative valve 071 is gradually opened, and the ignition system of the secondary combustion reactor 13 starts to operate;

[0141] When the temperature of the secondary combustion flue gas 121 reaches a set value (e.g., 750° C.), the ignition system of the secondary combustion reactor 12 stops operating;

[0142] The furnace lifting process is completed.

[0143] Step 2: Determine the working status of the primary combustion reactor 1 and the secondary combustion reactor 13

[0144] Read the monitoring data of the primary flue gas temperature sensor 142, the secondary flue gas dynamic pressure sensor 143, the secondary flue gas oxygen concentration sensor 144, and the secondary flue gas temperature sensor 122 and the secondary flue gas oxygen concentration sensor 081;

[0145] If the oxygen concentration of the primary fuel flue gas 141 is greater than zero, the pyrolysis reaction in the primary fuel reactor 1 has not occurred or has been interrupted, and an oxidation combustion reaction is taking place, and the secondary fuel blending air 102 is cut off, and the process goes to step 7;

[0146] If the oxygen concentration of the primary flue gas 141 is equal to zero, and the temperature of the primary flue gas 141 is higher than the temperature of the secondary flue gas 121, the secondary reactor 13 is not successfully started or extinguished, the ignition system of the secondary reactor 13 starts working again, and goes to step 4;

[0147] Otherwise, go to the next step.

[0148] Step 3: Optimize and adjust the secondary combustion air parameters

[0149] Read the monitoring data of the secondary combustion flue gas temperature sensor 122 and the secondary combustion flue gas oxygen concentration sensor 081:

[0150] When the oxygen concentration in the secondary combustion flue gas 121 is lower than a first set value (e.g., 4%), the flow rate of the secondary combustion air 102 is increased;

[0151] When the oxygen concentration in the secondary combustion flue gas 121 is higher than the second set value (e.g., 12%), the flow rate of the secondary combustion air 102 is reduced;

[0152] When the temperature of the secondary combustion flue gas 121 is lower than the first set value (e.g., 850° C.), the temperature of the secondary combustion air 102 is increased, and then its flow rate is reduced to adjust the oxygen concentration in the secondary combustion flue gas 121 to the lower limit of the allowable range;

[0153] When the temperature of the secondary combustion flue gas 121 is higher than the second set value (eg, 930° C.), the temperature of the secondary combustion air 102 is lowered, and then its flow rate is increased to adjust the oxygen concentration in the secondary combustion flue gas 121 to the upper limit of the allowable range.

[0154] Step 4: Obtain the theoretical calorific value of the flue gas 141 and the deviation between the theoretical calorific value and the target value

[0155] Combined with the set garbage calorific value and composition, as well as the data of each data monitoring point such as primary combustion air 023, primary combustion flue gas 141, secondary combustion flue gas 121, secondary combustion air 102, etc., the theoretical calorific value of primary combustion flue gas 141 is obtained according to the principle of conservation of energy;

[0156] The theoretical calorific value of the flue gas 141 is compared with the design target value to obtain the deviation between the theoretical calorific value of the flue gas 141 and the target value.

[0157] Step 5: Obtain the correction value of the fuel blended air 023 parameter

[0158] With the goal of minimizing the deviation between the theoretical calorific value of the flue gas 141 and the target calorific value, combined with the specific parameters of domestic waste, an optimization plan is constructed with the functional relationship between the calorific value of the flue gas 141 and the parameters of the fuel-blended combustion air 023 as constraints, and the optimal solution for the correction values ​​of parameters such as temperature and flow rate of the fuel-blended combustion air 023 is obtained.

[0159] Step 6: Optimize and adjust the parameters of the fuel-air mixture 023

[0160] According to the optimal solution of the correction values ​​of the process parameters such as the temperature and flow rate of the fuel-blended combustion air 023, it is judged whether the corrected values ​​of the temperature and flow rate of the fuel-blended combustion air 023 exceed the allowable value range;

[0161] When at least one of the corrected values ​​of the temperature and flow of the fuel-blended combustion air 023 does not exceed the value range, the one that exceeds the value range is adjusted with the limit value as the target, and the one that does not exceed the range is adjusted with the corrected value as the target, and the parameters of the fuel-blended combustion air 023 are gradually adjusted, and then go to the second step.

[0162] When the corrected values ​​of the temperature and flow rate of the fuel blended air 023 are both out of the value range, go to step 7;

[0163] Step 7: Reactor 1 enters direct combustion mode

[0164] Read the oxygen concentration, temperature, flow rate and other parameters of the first flue gas 141, adjust the parameters of the first combustion air 023, and ensure that the oxygen concentration of the first flue gas 141 is between the first and second set values ​​(for example, 6%-12%), and the temperature is between the first and second set values ​​(for example, 850-930°C):

[0165] When the oxygen concentration in the flue gas 141 is less than the first set value, the flow rate of the combustion air 023 is increased;

[0166] When the oxygen concentration in the first combustion flue gas 141 is greater than the second set value, the flow rate of the first combustion air 023 is reduced;

[0167] When the temperature of the flue gas 141 is lower than the first set value, the temperature of the combustion air 023 is increased;

[0168] When the temperature of the combustion flue gas 141 is greater than the second set value, the temperature of the combustion air 023 is reduced.

[0169] If the temperature of the first combustion air 023 reaches the upper limit, and still cannot ensure that the temperature of the first combustion flue gas 141 is increased to the first set value or above, go to step 8;

[0170] If the temperature of the combustion air 023 reaches the lower limit, and still cannot ensure that the temperature of the flue gas 141 drops to the second set value or below, the flow of the combustion air 023 is cut off and the process goes to the second step.

[0171] Step 8: Shutdown Mode

[0172] The heat recovery of the first fuel mixed combustion air 023 and the second fuel mixed combustion air 102 is cancelled, that is, the first fuel mixed combustion air 023 is all the first fuel direct supply cold air 033, and the second fuel mixed combustion air 102 is all the second fuel direct supply cold air 063, until the temperature of the first fuel flue gas 141 is reduced to below the set value (for example, 120°C) and the oxygen concentration is increased to above the set value (for example, 20%), and can be maintained for a set time (for example, 15 minutes);

[0173] Then cut off the first fuel blending air 023, the second fuel blending air 102, and shut down.

[0174] Thereby achieving dynamic and precise control of process parameters such as primary combustion air 023 and secondary combustion air 102 in different operation stages of the small-scale domestic waste clean heat treatment system, so that the coupled reaction of garbage in the primary combustion reactor 1 generates high-quality primary combustion flue gas 141, and the primary combustion flue gas 141 undergoes an efficient and stable oxidation reaction in the secondary combustion reactor 13, thereby achieving the unity of economy and environmental protection in the process of harmless treatment of domestic waste.

[0175] Example 2

[0176] like Figure 2 As shown, this embodiment proposes a small-scale household waste clean heat treatment system and a dynamic heat recovery method thereof, which is different from the embodiment 1 in that the sources of the first fuel heat recovery cold air 043 and the first fuel direct supply cold air 033 constituting the first fuel mixed combustion air 023, and the sources of the second fuel heat recovery cold air 073 and the second fuel direct supply cold air 063 constituting the second fuel mixed combustion air 102 are different. Specifically, this embodiment:

[0177] ① It does not include a direct fuel supply fan 3 and a heat recovery fan 4, but only includes a fuel fan 15, and the outlet of the fuel fan 15 is divided into two routes: a direct fuel supply pipe 032 and a heat recovery pipe 042;

[0178] ② It does not include your direct supply fan 6 and secondary fuel heat recovery fan 7, but only includes the secondary fuel fan 16. The outlet of the secondary fuel fan 16 is divided into two routes: the secondary fuel direct supply pipe 062 and the secondary fuel heat recovery pipe 072.

[0179] During operation, the temperature of the first-fuel blended air 023 is regulated by the opening of the first-fuel direct supply valve 031 and the first-fuel heat recovery valve 041, and the flow rate of the first-fuel blended air 023 is regulated in coordination with the speed of the first-fuel blower 15; similarly, the temperature of the second-fuel blended air 102 is regulated by the opening of the second-fuel direct supply valve 061 and the second-fuel heat recovery valve 071, and the flow rate of the second-fuel blended air 102 is regulated in coordination with the speed of the second-fuel blower 16.

[0180] It should be noted that the small-scale domestic waste clean heat treatment system of the present invention is mainly used for small-scale domestic waste incinerators, but can also be used in other occasions, including but not limited to medium-sized domestic waste heat treatment systems, medical waste heat treatment systems, industrial waste heat treatment systems, water surface floating waste heat treatment systems, etc.

[0181] The above are preferred embodiments of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications may be made without departing from the principles of the present invention. These improvements and modifications should also be considered as the protection scope of the present invention. For example:

[0182] ① The primary combustion air blower 15 and the secondary combustion air blower 16 are cancelled and replaced by sharing the same gas source;

[0183] ② Move the secondary fuel flue gas oxygen concentration sensor 081 forward to the secondary fuel flue gas pipe 12;

[0184] ③ Replace one or both of the primary-fired heat regenerator 11 and the secondary-fired heat regenerator 9 with two or more heat regenerators connected in series;

[0185] ④Specially point out that a certain fan is a variable frequency fan.

Claims

1. A small-scale domestic waste clean heat treatment system, characterized in that: It comprises a primary combustion reactor (1), a secondary combustion reactor (13), a primary combustion heat regenerator (11), and a secondary combustion heat regenerator (9); and further comprises: a flue gas pipe (14), one end of the flue gas pipe (14) being connected to the first combustion reactor (1), and the other end of the flue gas pipe (14) being connected to the second combustion reactor (13); A fuel direct supply pipe (032) and a fuel heat recovery pipe (042) are arranged in parallel, and a fuel direct supply valve (031) and a fuel heat recovery valve (041) are respectively provided on the fuel direct supply pipe (032) and the fuel heat recovery pipe (042). The fuel heat recovery pipe (042) is connected to the air side inlet of the fuel heat recovery device (11) downstream of the fuel heat recovery valve (041). The fuel direct supply pipe (032) and the fuel heat recovery pipe (042) are connected to one end of a fuel intake pipe (2) downstream of the fuel direct supply valve (031) and downstream of the fuel heat recovery pipe (042). The other end of the fuel intake pipe (2) is connected to a fuel reactor (1); A second fuel direct supply pipe (062) and a second fuel heat recovery pipe (072) are arranged in parallel, and the second fuel direct supply pipe (062) and the second fuel heat recovery pipe (072) are respectively provided with a second fuel direct supply valve (061) and a second fuel heat recovery valve (071), and the second fuel heat recovery pipe (072) is connected to the air side inlet of the second fuel heat recovery device (9) downstream of the second fuel direct supply valve (061), and the second fuel direct supply pipe (062) and the second fuel heat recovery pipe (072) are connected to one end of the second fuel air intake pipe (10) downstream of the second fuel direct supply valve (061), and the other end of the second fuel air intake pipe (10) is connected to the second fuel reactor (13); A secondary combustion flue gas pipe (12), one end of the secondary combustion flue gas pipe (12) is connected to the outlet of the secondary combustion reactor (13), and the other end is connected to the flue gas side inlet of the primary combustion regenerator (11); A regenerator connecting pipe (5), one end of which is connected to the flue gas outlet of the first-burning regenerator (11), and the other end of which is connected to the flue gas inlet of the second-burning regenerator (9); A flue gas downward delivery pipe (8), one end of which is connected to the outlet of the flue gas side of the secondary combustion regenerator (9), and the other end of which is connected to the downstream.

2. The small-scale domestic waste clean heat treatment system according to claim 1 is characterized in that: The air inlet ends of the first fuel direct supply pipe (032), the first fuel heat recovery pipe (042), the second fuel direct supply pipe (062), and the second fuel heat recovery pipe (072) are respectively connected to the outlets of the first fuel direct supply fan (3), the first fuel heat recovery fan (4), the second fuel direct supply fan (6), and the second fuel heat recovery fan (7).

3. The small-scale domestic waste clean heat treatment system according to claim 2 is characterized in that: The first fuel direct supply pipe (032) and the first fuel heat recovery pipe (042) are connected to the outlet of the first fuel blower (15); the second fuel direct supply pipe (062) and the second fuel heat recovery pipe (072) are connected to the outlet of the second fuel blower (16).

4. The small-scale domestic waste clean heat treatment system according to claim 3 is characterized in that: The flue gas pipe (14) is provided with at least one of a flue gas temperature sensor (142), a flue gas dynamic pressure sensor (143), and a flue gas oxygen concentration sensor (144).

5. The small-scale household waste clean heat treatment system according to claim 4 is characterized in that: The fuel intake pipe (2) is provided with at least one of a fuel intake air temperature sensor (021) and a fuel intake air dynamic pressure sensor (022).

6. The small-scale domestic waste clean heat treatment system according to claim 5 is characterized in that: The secondary fuel intake pipe (10) is provided with a secondary fuel intake temperature sensor (101).

7. The small-scale domestic waste clean heat treatment system according to claim 6 is characterized in that: The secondary combustion smoke pipe (12) is provided with a secondary combustion smoke temperature sensor (122), and the secondary combustion smoke oxygen concentration sensor (081) is provided on the smoke down pipe (8).

8. A dynamic heat recovery method for a small-scale domestic waste clean heat treatment system, using the small-scale domestic waste clean heat treatment system according to claim 7, characterized in that: The steps include: The secondary combustion flue gas (121) discharged from the secondary combustion reactor (13) is first passed through a fuel regenerator (11) to heat a fuel recovery cold air (043) from a fuel recovery pipe (042) to form a fuel recovery hot air (044), and then the fuel recovery hot air (044) is mixed with a fuel direct supply cold air (033) from the fuel direct supply pipe (032) to obtain a fuel-blended combustion air (023); the parameter adjustment method of the fuel-blended combustion air (023) is as follows: By dynamically adjusting the mixing ratio of the first fuel return hot air (044) and the first fuel direct supply cold air (033), the temperature of the first fuel mixed combustion air (023) is dynamically controlled; The flow rate of the fuel-blended combustion air (023) is dynamically controlled by dynamically and synchronously adjusting the flow rate of the fuel-returned hot air (044) and the fuel-direct-supply cold air (033).

9. The dynamic heat recovery method of a small-scale domestic waste clean heat treatment system according to claim 8, characterized in that: The steps include: After being discharged from the secondary fuel flue gas (121) from the primary fuel reheater (11), the secondary fuel flue gas (121) is sent to the secondary fuel reheater (9), and the secondary fuel reheating cold air (073) from the secondary fuel reheating pipe (072) is heated to become secondary fuel reheating hot air (074), and then the secondary fuel reheating hot air (074) is mixed with the secondary fuel direct supply cold air (063) from the secondary fuel direct supply pipe (062) to obtain secondary fuel mixed combustion air (102). The parameter adjustment method of the secondary fuel mixed combustion air (102) is as follows: By dynamically adjusting the mixing ratio of the secondary fuel heat recovery hot air (074) and the secondary fuel direct supply cold air (063), the temperature of the secondary fuel mixed combustion air (102) is dynamically controlled; The flow rate of the secondary fuel blending air (102) is dynamically controlled by dynamically and synchronously adjusting the flow rates of the secondary fuel reheated hot air (074) and the secondary fuel direct supply cold air (063).

10. The dynamic heat recovery method of a small-scale domestic waste clean heat treatment system according to claim 9, characterized in that: The dynamic control strategy of the parameters of the fuel blended air (023) is: The theoretical calorific value of the first-fuel flue gas (141) is obtained based on the monitoring data of the temperature, flow rate and other parameters of the first-fuel mixed combustion air (023), the second-fuel mixed combustion air (102), the first-fuel flue gas (141) and the second-fuel flue gas (121), as well as the physical property parameters of the garbage, and then the deviation between the theoretical calorific value of the first-fuel flue gas (141) and the set target value is obtained; According to the deviation between the theoretical calorific value of the flue gas (141) and the set target value, the temperature and flow rate correction values ​​required for the fuel-mixed combustion air (023) are obtained; According to the correction value, the parameters of the fuel-blended combustion air (023) are adjusted; Thus, the relatively optimal parameters of the fuel-blended combustion air (023) are obtained.

11. The dynamic heat recovery method of a small-scale domestic waste clean heat treatment system according to claim 10, characterized in that: The dynamic control strategy of the secondary combustion air (102) parameters is: The monitored values ​​of the temperature and oxygen concentration of the secondary combustion flue gas (121) are compared with the set target values ​​respectively, and the deviation between the monitored values ​​and the target values ​​is used as a basis for dynamically adjusting the temperature and flow rate of the secondary combustion air (102); When the temperature of the secondary combustion flue gas (121) is higher than a set upper limit of a target value, or lower than a set lower limit of a target value, the temperature of the secondary combustion air (102) is correspondingly lowered or raised; When the oxygen concentration in the secondary combustion flue gas (121) is higher than a set target upper limit, or lower than a set target lower limit, the flow rate of the secondary combustion air (102) is correspondingly reduced or increased.

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