Self-heating operation control method based on FRF mode and chemical looping combustion system

Abstract

The invention relates to a self-heating operation control method based on an FRF mode and a chemical looping combustion system.The method comprises the steps that 1, a heat load instruction requirement is obtained, and the temperature of an air reactor is increased or decreased by adjusting the opening degree of an oxygen carrier circulation control valve and adjusting increase or decrease of the oxygen carrier circulation flow; step 2, along with the increase or decrease of the circulation flow of the oxygen carrier, the temperature of the combustion reactor is increased or decreased along with the increase or decrease of the circulation flow of the oxygen carrier; 3, according to the temperature deviation set value of the combustion reactor, the opening degree of a fuel flow valve is continuously changed to control the fuel feeding amount of the fuel reactor, so that the reduction reaction of the fuel reactor is controlled, and stable self-heating operation of the fuel reactor is achieved. According to the method, the response speed of the external thermal load instruction can be guaranteed preferentially, then the stability of the FR temperature is achieved by adjusting the fuel quantity, and self-heating stable operation of the whole chemical continuous combustion system is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of automatic control of chemical looping combustion, and particularly relates to a self-heating operation control method based on an FRF mode and a chemical looping combustion system. BACKGROUND

[0002] Chemical looping combustion (CLC) technology is to use oxygen carriers (OC) prepared by solid particles of metal oxides to circulate between an air reactor (AR) and a fuel reactor (FR) to transfer oxygen in air to the fuel reactor in the form of lattice oxygen to chemically react with fuel. Since fuel does not contact air and combustion-generated carbon dioxide is not diluted by other gases (mainly nitrogen) in air in the whole process of chemical looping combustion, the carbon dioxide concentration at the outlet of the fuel reactor can reach more than 90%, and there is no need to separate carbon dioxide from other gases before capture, so that carbon dioxide generated by combustion reaction can be captured at low cost and low energy consumption. In summary, chemical looping combustion technology is a new combustion technology that can greatly reduce carbon dioxide emissions at low cost.

[0003] The oxidation reaction of the oxygen carrier in the AR is an exothermic reaction, and the fuel gasification and oxygen carrier reduction reactions in the FR are endothermic reactions. When normally operating, the heat-carrying capacity of the oxygen carrier is used to maintain the normal operating temperature of each reactor when circulating between the FR and the AR.

[0004] At present, most chemical looping devices use external heat sources (natural gas or electric heating) to maintain the reactor temperatures of the AR and the FR to ensure the normal operation of the chemical looping device, and self-heating operation has not been achieved. The core problem is that the heat balance between the FR and the AR reactors cannot be controlled. SUMMARY

[0005] The purpose of the present application is to provide a self-heating operation control method based on an FRF mode and a chemical looping combustion system to realize self-heating operation of the chemical looping combustion system.

[0006] The present application provides a self-heating operation control method based on an FRF mode, which comprises the following steps:

[0007] Step 1: Obtain the heat load instruction requirement, and increase or decrease the circulating flow of the oxygen carrier by adjusting the opening degree of the oxygen carrier circulation regulating valve to increase or decrease the temperature of the air reactor;

[0008] Step 2: As the circulating flow of the oxygen carrier increases or decreases, the temperature of the combustion reactor increases or decreases accordingly;

[0009] Step 3, according to the size of the fuel reactor temperature deviates from the set value, constantly changing the opening of the fuel flow valve control fuel reactor fuel feeding amount, to control the reduction reaction of the fuel reactor, to achieve stable self-heating operation of the fuel reactor.

[0010] Further, in step 1, the heat load controller obtains the heat load instruction requirement and issues a control instruction.

[0011] Further, in step 1, the oxygen carrier circulation flow control valve obtains the control instruction issued by the heat load regulator, and adjusts the increase or decrease of the oxygen carrier circulation flow.

[0012] Further, in step 3, the fuel reactor temperature controller determines whether the temperature of the combustion reactor deviates from the set value, and if so, issues a control instruction.

[0013] Further, in step 1, when the heat load instruction is 4MWth, the fuel feeding amount is 0.8-1.2t / h.

[0014] Further, in step 2, the fuel reactor temperature set value is 950℃, the flow rate is maintained at 1.5-2.5m / s, the oxygen carrier circulation flow is 150-200t / h, and the flow rate is maintained at 9-10m / s.

[0015] The application also provides a chemical looping combustion system, comprising a combustion reactor, an air reactor, a heat load controller, a fuel control valve, a fuel reactor temperature controller, and an oxygen carrier circulation flow control valve.

[0016] The combustion reactor and the air reactor are connected by the oxygen carrier circulation flow control valve; the heat load controller is connected to the oxygen carrier circulation flow control valve; the fuel control valve is connected to the combustion reactor; the fuel reactor temperature controller is connected to the fuel control valve and the combustion reactor;

[0017] The heat load controller is used to obtain the heat load instruction requirement and issue a control instruction;

[0018] The oxygen carrier circulation flow control valve is used to obtain the control instruction, adjust the increase or decrease of the oxygen carrier circulation flow, and increase or decrease the temperature of the air reactor;

[0019] The fuel reactor temperature controller is used to control the reduction reaction of the fuel reactor by constantly changing the opening of the fuel flow valve to control the fuel feeding amount of the fuel reactor when the temperature of the combustion reactor increases or decreases with the increase or decrease of the oxygen carrier circulation flow, to achieve stable self-heating operation of the fuel reactor.

[0020] Further, the heat load controller adopts a proportional integral controller.

[0021] Further, the fuel reactor temperature controller adopts a proportional integral controller.

[0022] By the above scheme, the response speed of the external heat load instruction is preferentially ensured, and the FR temperature is stabilized by adjusting the fuel quantity, so that the self-heating stable operation of the entire chemical chain combustion system is realized.

[0023] The above description is only a summary of the technical scheme of the present application. In order to more clearly understand the technical means of the present application and can be implemented in accordance with the content of the specification, the following is a preferred embodiment of the present application and detailed description with the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The flow chart of the self-heating operation control method based on the FRF mode of the present application;

[0025] Figure 2 The structure diagram of the chemical chain combustion system of the present application. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application will be further described in detail below in combination with the drawings and examples. The following examples are used to illustrate the present application, but not to limit the scope of the present application.

[0027] Referring to Figure 1 The embodiment provides a self-heating operation control method based on a FRF mode (Fuel Reactor Follow Mode, FRF, fuel reactor follow mode), which comprises the following steps:

[0028] Step S1, the heat load instruction requirement is obtained, the increase or decrease of the oxygen carrier circulation flow is adjusted by adjusting the opening degree of the oxygen carrier circulation adjusting valve, so that the temperature of the air reactor is increased or decreased.

[0029] Step S2, as the oxygen carrier circulation flow increases or decreases, the temperature of the combustion reactor increases or decreases.

[0030] Step S3, according to the size of the deviation of the combustion reactor temperature from the set value, the opening degree of the fuel flow valve is changed to control the fuel feeding amount of the fuel reactor, so as to control the reduction reaction of the fuel reactor and realize the stable self-heating operation of the fuel reactor.

[0031] In a specific example, according to the deviation between the set value and the actual value, an output adjustment instruction is outputted, and the relevant parameters are as follows: when the heat load instruction is 4MWth, the fuel feeding amount is 0.8-1.2t / h, the fuel reactor temperature set value is 950℃, the flow rate is kept at 1.5-2.5m / s, the oxygen carrier circulation flow rate is 150-200t / h, and the flow rate is kept at 9-10m / s.

[0032] Referring to Figure 2 The embodiment also provides a chemical looping combustion system, and the system comprises the heat load controller and the fuel reactor temperature controller.

[0033] LOAD: heat load

[0034] LS: heat load instruction

[0035] LC: heat load controller (proportional integral controller)

[0036] FL_V: fuel control valve

[0037] FRS: fuel reactor temperature set value

[0038] FRT: fuel reactor temperature, ℃

[0039] TC: fuel reactor temperature controller (proportional integral controller)

[0040] OC_V: oxygen carrier circulation flow rate control valve

[0041] FR: combustion reactor

[0042] AR: air reactor.

[0043] The combustion reactor (FR) is connected with the air reactor (AR) through the oxygen carrier circulation flow rate control valve (OC_V); the heat load controller (LC) is connected with the oxygen carrier circulation flow rate control valve (OC_V); the fuel control valve (FL_V) is connected with the combustion reactor (FR); and the fuel reactor temperature controller (TC) is connected with the fuel control valve (FL_V) and the combustion reactor (FR).

[0044] The heat load controller (LC) is used to acquire the heat load instruction (LS) requirement and issue a control instruction. The oxygen carrier circulation flow control valve (OC_V) is used to acquire the control instruction and adjust the increase or decrease of the oxygen carrier circulation flow to increase or decrease the temperature of the air reactor (AR). The fuel reactor temperature controller (TC) is used to continuously change the opening of the fuel flow valve (FL_V) to control the fuel feeding amount of the fuel reactor (FR) to control the reduction reaction of the fuel reactor (FR) and realize the stable self-heating operation of the fuel reactor when the temperature of the fuel reactor (FR) increases or decreases with the increase or decrease of the oxygen carrier circulation flow according to the size of the deviation of the fuel reactor temperature from the set value.

[0045] Firstly, according to the heat load instruction (LS) requirement, the heat load regulator (LC) issues an instruction to adjust the increase or decrease of the oxygen carrier circulation flow by adjusting the opening of the oxygen carrier circulation valve (OC_V) to quickly increase or decrease the temperature of the air reactor (AR). Since the oxidation reaction speed of the oxygen carrier is fast, the heat load instruction can be quickly responded.

[0046] With the increase or decrease of the oxygen carrier circulation flow, the temperature of the fuel reactor (FR) increases or decreases, at which time the fuel reactor temperature controller (TC) continuously changes the fuel feeding amount of the fuel reactor (FR) to control the reduction reaction of the fuel reactor (FR) and realize the stable self-heating operation of the fuel reactor (FR) according to the size of the deviation of the fuel reactor temperature from the fuel reactor set value (FRS).

[0047] Therefore, the control mode is to let the AR track the requirement of the external load first, and let the FR change with the change of the AR, so it is called the "fuel reactor following" control mode.

[0048] Through the control method, the response speed of the external heat load instruction can be preferentially ensured, and the stability of the FR temperature can be realized by adjusting the fuel amount to realize the self-heating stable operation of the entire chemical continuous combustion system.

[0049] The above only describes the preferred embodiments of the present application and is not used to limit the present application. It should be pointed out that for ordinary skilled persons in the technical field, several improvements and modifications can be made without departing from the technical principles of the present application, and these improvements and modifications should be considered as the protection scope of the present application.

Claims

1. A self-heating operation control method based on FRF method, characterized in that: The steps include: Step 1: Obtain heat load instruction requirements, adjust the oxygen carrier circulation valve opening, adjust the oxygen carrier circulation flow rate to increase or decrease, and increase or decrease the temperature of the air reactor; Step 2: As the oxygen carrier circulation flow rate increases or decreases, the temperature of the combustion reactor increases or decreases accordingly; Step 3: According to the deviation of the combustion reactor temperature from the set value, the opening of the fuel flow valve is continuously changed to control the fuel feed amount of the fuel reactor, so as to control the reduction reaction of the fuel reactor and realize stable self-heating operation of the fuel reactor.

2. The self-heating operation control method based on FRF method according to claim 1 is characterized in that: In step 1, the heat load controller obtains the heat load instruction requirement and issues a control instruction.

3. The self-heating operation control method based on FRF method according to claim 2 is characterized in that: In step 1, the oxygen carrier circulation flow control valve obtains the control instruction issued by the heat load regulator to adjust the increase or decrease of the oxygen carrier circulation flow.

4. The self-heating operation control method based on FRF method according to claim 3 is characterized in that: In step 3, the fuel reactor temperature controller determines whether the temperature of the combustion reactor deviates from the set value, and if so, issues a control instruction.

5. The self-heating operation control method based on FRF method according to claim 1 is characterized in that: In step 1, when the heat load instruction is 4MWth, the fuel feed rate is 0.8-1.2t / h.

6. The self-heating operation control method based on FRF method according to claim 5 is characterized in that: In step 2, the temperature setting value of the fuel reactor is 950° C., the flow rate is maintained at 1.5-2.5 m / s, the circulation flow rate of the oxygen carrier is 150-200 t / h, and the flow rate is maintained at 9-10 m / s.

7. A chemical looping combustion system, characterized in that: It includes a combustion reactor, an air reactor, a heat load controller, a fuel control valve, a fuel reactor temperature controller, and an oxygen carrier circulation flow control valve; The combustion reactor and the air reactor are connected via an oxygen carrier circulation flow control valve; the heat load controller is connected to the oxygen carrier circulation flow control valve; the fuel control valve is connected to the combustion reactor; and the fuel reactor temperature controller is connected to the fuel control valve and the combustion reactor; The heat load controller is used to obtain heat load instruction requirements and issue control instructions; The oxygen carrier circulation flow control valve is used to obtain the control instruction and adjust the oxygen carrier circulation flow rate to increase or decrease, so as to increase or decrease the temperature of the air reactor; The fuel reactor temperature controller is used to control the fuel feed amount of the fuel reactor by continuously changing the opening of the fuel flow valve according to the deviation of the combustion reactor temperature from the set value when the temperature of the combustion reactor increases or decreases with the increase or decrease of the oxygen carrier circulation flow rate, so as to control the reduction reaction of the fuel reactor and realize stable self-heating operation of the fuel reactor.

8. The chemical looping combustion system according to claim 7, characterized in that: The heat load controller adopts a proportional integral controller.

9. The chemical looping combustion system according to claim 8, characterized in that: The fuel reactor temperature controller adopts a proportional integral controller.

Images