Microwave plasma adaptive rock breaking device for microwave-insensitive rocks and method for using the same

A method for using a microwave plasma adaptive rock breaking device for microwave-insensitive rocks, the microwave plasma adaptive rock breaking device comprising a microwave system, a microwave plasma conversion system and a cutter head system, wherein the microwave system and the microwave plasma conversion system are mounted in the cutter head system, and the microwave system is connected with the microwave plasma conversion system, the method comprising the following steps:

• Step 1:
• through a control panel of a full-section hard rock tunnel boring machine, switching on the cutter head for tunneling, and according to the performance of the full-section hard rock tunnel boring machine, setting rotating speed and propulsion force of the cutter head to the maximum value for safe work through the control panel, that is, the rotating speed is V1, and the propulsion force is N;
• performing field measurement to obtain propulsion speed V2 without switching on the microwave system, and starting the drive motor I to switch on the rotary waveguide I, wherein the rotating speed of the rotary waveguide I is the same as the angular velocity of the cutter head;
• Step 2:
• switching on any microwave generator, adjusting the microwave conversion switches, closing the input port of the microwave plasma applicator on the microwave conversion switch, opening the input port of the microwave heater on each ordinary microwave applicators, and switching on all microwave heaters, wherein because each microwave generator is divided into a plurality of microwave heaters to output microwaves, reflections generated by each microwave heater are accumulated to achieve the switched-on microwave generator, during the process of detecting the matching performance of the rocks, the sum of the output powers of the microwave heaters is PkW, the output power of the single microwave heater is 1-3 kW, if the number of the microwave heaters is k, then P=(1-3)k, the microwave generators are not damaged when the output power is fully emitted, reflection coefficients are monitored through the output of the microwave generators, the lower limit of the reflection coefficients is set as a, the upper limit on the reflection coefficients is set as b, the lower limit a and the upper limit b of the reflection coefficients can be obtained through laboratory experiment, wherein the lower limit a of the reflection coefficients represents reflection coefficients corresponding to microwave-insensitive rocks, and the upper limit b of the reflection coefficients represents maximum reflection coefficients which can be borne by the microwave generators,
• wherein (1) when the reflection coefficients are in a safe range between the lower limit a of the reflection coefficients and the upper limit b of the reflection coefficients, gradually increasing the microwave power of the microwave generators to a full power state, wherein if the microwave power reaches the maximum power, the reflection coefficients are still between the lower limit a and the upper limit b of the reflection coefficients, the microwave generators continue to work with the microwave power parameters at this time;
• if the reflection coefficients exceed the safe range between the lower limit a and the upper limit b of the reflection coefficient in the process of gradually increasing the microwave power, and the microwave power has not yet reached the maximum power, adjusting the microwave conversion switches, opening the input ports of the microwave plasma applicators to heat the rocks, and distributing the remaining microwave power to the microwave plasma applicators for output,
• (2) when the reflection coefficients are less than the lower limit a of the reflection coefficients, keeping the single-port microwave output power PkW, while adjusting the microwave conversion switches, opening the input ports of the microwave plasma applicators to heat the rocks, wherein the power of the single plasma torch is ¼P kW, observing whether the reflection coefficients increase or not, if it increases to the safe range between the lower limit a of the reflection coefficients and the upper limit b of the reflection coefficients, it indicates that a high temperature of the plasma torches increases the microwave sensitivity of the rocks, then continues to increase the single-port microwave power of the microwave heaters, when the maximum power is achieved, the reflection coefficients are still in the safe range between the lower limit a and the upper limit b of the reflection coefficients, the microwave generators continue to work with the microwaves parameters at this time;
• when the reflection coefficients exceed the safe range between the lower limit a and the upper limit b of the reflection coefficient during the heating process of the rocks, and when the power of the microwave system has not yet reached the maximum power, the residual power is distributed and output through the microwave plasma applicators,
• (3) when the reflection coefficients are greater than the upper limit b of the reflection coefficients, adjusting the microwave conversion switches, opening input ends of the microwave plasma applicators, applying power to the input ports of the microwave plasma applicators, and performing outputting through the microwave plasma applicators;
• Step 3:
• after the microwave power parameters are determined, the rotating speed of the cutter head is V1, and the propulsion force is N, according to the field measurement results, obtaining the propulsion speed V3 when the microwave system is switched on, and if V3>V2, continuing the tunneling work;
• if V3=V2, and an output mode is ordinary microwave, switching to the output of all of the plasma applicators, and continuing the tunneling work;
• if V3<V2, setting the propulsion force to 0, stopping propulsion, and switching on the microwave system, repeating Steps 1 to 2, when the surfaces of the rocks crack, switching off the microwave system, setting the propulsion force to N to start propulsion, wherein the propulsion distance is 5-8 times of the penetration depth of the rocks, setting the propulsion force to 0 again to stop propulsion, switching on the microwave system, when the surfaces of the rocks crack, switching off the microwave system, and repeating the process of microwave irradiation-propulsion to perform the tunneling work;
• and
• Step 4:
• setting the rotary waveguides II to rotate at different rotating speeds, repeating the Steps 1 to 3, comparing the increase of the propulsion speed V3 compared to the propulsion speed V2, and determining the optimal rotating speed of the rotary waveguides II.