Multi-stage temperature control method for mine refuge chamber

Abstract

The invention discloses a multistage temperature control method for a mine refuge chamber, relates to the technical field of mine safety, and solves the technical problems that a temperature control strategy of an existing refuge chamber is insufficient in control adaptability, and effective cooling cannot be carried out. The method comprises the steps that corresponding chamber types and corresponding temperature control strategies are determined based on initial surrounding rock temperature and chamber refuge capacity, the chamber types comprise low temperature, medium-low temperature, medium temperature, medium-high temperature and high temperature, the temperature control strategy corresponding to the low temperature is surrounding rock cooling, and the temperature control strategy corresponding to the medium-low temperature is aeration cooling or phase change cooling; the medium temperature corresponding temperature control strategy is enhanced ventilation cooling or phase change cooling, the medium-high temperature corresponding temperature control strategy is surrounding rock cold storage and compressed air composite cooling or surrounding rock cold storage and phase change composite cooling, and the high temperature corresponding temperature control strategy is surrounding rock cold storage and compressed air phase change composite cooling; according to different external environment temperatures of the refuge chamber, a graded cooling strategy is flexibly selected, and temperature control of the refuge chamber is effectively guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of mine safety, and in particular to a multi-stage temperature control method for a mine refuge chamber. Background Art

[0002] The working environment of coal mines is complex and dangerous. Disasters such as gas explosions, floods, and fires can easily cause mass deaths and injuries. As a disaster shelter space isolated from the mine environment, the function of the refuge chamber is to provide a safe place and an environment for survival for people in distress who cannot be evacuated within a limited time. It is the last and most important emergency shelter facility when an emergency occurs. In 2010, all mines were required to complete the construction of emergency shelter systems within 3 years. In 2012, it was stipulated that if drilling or special pipelines cannot guarantee the reliable realization of related functions, relevant supporting facilities such as self-contained oxygen supply, temperature and humidity adjustment, and large-capacity backup power supply should be reasonably designed and selected. In 2013, it was clearly stated that refuge chambers should give priority to special drilling and special pipeline supply (wind) and other methods; according to the 2016 "Coal Mine Safety Regulations", the refuge chambers in the mining area must be connected to the mine compressed air pipeline, and its rated protection time shall not be less than 96h.

[0003] In terms of temperature control of underground refuge chambers in coal mines, common refrigeration methods include liquid CO2 cooling, ice storage cooling, explosion-proof air conditioning cooling, ventilation cooling, and phase change cooling. Liquid CO2 cooling has poor adaptability in high-temperature environments above 32°C and there is a risk of leakage. Although ice storage cooling has a wide range of applications, its maintenance cost is high, and the matching compressor and pneumatic fan are easily damaged. Explosion-proof air conditioning cooling consumes a lot of power and is not suitable for underground coal mine environments with power outages due to disasters; ventilation cooling has a low cost, but it is difficult to meet the temperature control requirements of high-temperature mine refuge chambers; phase change cooling does not require maintenance, but the temperature control effect is limited in high-temperature mine refuge chambers. Therefore, for different refuge chamber temperatures, a more effective and adaptable comprehensive temperature control strategy for refuge chambers is urgently needed. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides a multi-stage temperature control method for a mine refuge chamber, which solves the technical problem that the temperature control strategy of the existing refuge chamber has insufficient control adaptability and cannot effectively cool down.

[0005] The multi-stage temperature control method of the mine refuge chamber includes: determining the initial surrounding rock temperature of the mine refuge chamber, determining the corresponding chamber type and the corresponding temperature control strategy based on the initial surrounding rock temperature combined with the refuge capacity of the chamber, the chamber types include low temperature, medium-low temperature, medium temperature, medium-high temperature and high temperature, the temperature control strategy corresponding to low temperature is surrounding rock cooling, the temperature control strategy corresponding to medium-low temperature is ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium temperature is enhanced ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium-high temperature is surrounding rock cold storage and compressed air composite cooling or surrounding rock cold storage and phase change composite cooling, and the temperature control strategy corresponding to high temperature is surrounding rock cold storage and compressed air phase change composite cooling. The initial surrounding rock temperature combined with the refuge capacity of the chamber will be used as the decision condition of the refuge chamber temperature control plan, and the initial rock temperature will be used as an important decision basis for the plan.

[0006] Furthermore, the calculation process of surrounding rock cold storage and compressed air plus phase change composite cooling includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , wind current takes away energy Q P 、Heat absorption by the inner wall of surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convective heat transfer condition of the outer boundary of the phase change plate and the convective heat transfer coefficient h on the surface of the phase change plate. mc , otherwise continue the trial calculation.

[0007] Furthermore, the calculation process of surrounding rock cold storage and compressed air plus phase change composite cooling includes:

[0008] a. Input initial parameters and set Q a = 0, and read the non-contact surface temperature T of the phase change seat from Fluent non-c .

[0009] b. Set the increment of ΔQ = 0.1W and increase the heat absorption of the air Q a =Q a +ΔQ.

[0010] c. According to Q a , the air temperature T can be obtained f , and then calculate the surface convection heat transfer coefficient h of the phase change seat fPCP and the convection heat transfer coefficient h of the inner wall of the surrounding rock fw According to the air temperature T f and the convective heat transfer coefficient k fw The temperature distribution of the surrounding rock and the temperature of the inner wall of the surrounding rock can be obtained, and the heat storage capacity Q of the surrounding rock can be calculated. w And the heat storage Q of the non-contact surface of the phase change seat non-c .

[0011] d. Determine Q P +Q a +Q w +Q non +Q non-c The magnitude relationship with the magnitude of Q. If Q P +Q a +Q w +Q non +Q non-c <Q, it indicates that the air temperature value is less than the true result at this time. Then, it is necessary to return to step 2), increase the air heat absorption and recalculate until Q P +Q a +Q w +Q non +Q non-c ≥Q to stop the calculation.

[0012] e. Save the calculated air temperature T at this time f and the convective heat transfer coefficient h on the outer surface of the phase change seat fPCP Output them to Fluent as the outer boundary conditions of the non-contact surface of the phase change seat.

[0013] Furthermore, when it is determined that the mine refuge chamber belongs to the medium-low temperature section, medium temperature section or medium-high temperature section, calculate the cooling cost when using ventilation cooling, enhanced ventilation cooling or compressed air cooling based on the mine refuge chamber information, compare it with the cooling cost of phase change cooling in the same temperature section, and then select the cooling method with lower cooling cost. The mine refuge chamber information includes the geographical location of the mine and the burial depth of the refuge chamber.

[0014] Furthermore, the influencing factors of the cooling cost of each scheme include the initial investment and maintenance cost. The cooling cost of the ventilation cooling, enhanced ventilation cooling or compressed air cooling scheme is obtained through the device purchase cost and maintenance cost. The device includes a compressed air chamber, a fan, an air duct and its accessories, and an end air outlet; the cooling cost of the phase change cooling is evaluated and calculated based on the real-time prices of the phase change material and the phase change encapsulation material in combination with the engineering situation and market prices.

[0015] Furthermore, the phase change cooling can be realized by using a phase change plate. The calculation process of the convective heat transfer conditions on the outer boundary of the phase change plate includes: calculating the air temperature by the trial method. When the sum of the heat absorption Q of the air itself a , the heat absorption Q of the surrounding rock inner wall surface w and the heat absorption Q of the phase change plate pcp is equal to the heat generation Q of the indoor heat source, the air temperature is the correct solution. At this time, the final result is output as the convective heat transfer conditions on the outer boundary of the phase change plate, that is, the air temperature T f and the convective heat transfer coefficient h on the surface of the phase change plate PCP , otherwise continue the trial calculation.

[0016] Furthermore, the phase change cooling is realized by using a phase changeable seat. The calculation process of the convection heat transfer condition of the non-contact surface of the phase change seat includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the non-contact surface of the phase change seat, that is, the air temperature T f and the convective heat transfer coefficient h non-c , otherwise continue the trial calculation.

[0017] Furthermore, the phase change cooling is realized by using phase change panels and phase change seats, and the air temperature is calculated by trial and error. a , the heat absorbed by the inner wall of the surrounding rock Q w , Phase change plate heat absorption Q PCP , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the outer boundary of the non-contact surface of the phase change seat and the convection heat transfer coefficient h of the non-contact surface of the phase change seat. non-c , otherwise continue the trial calculation.

[0018] Furthermore, the ventilation and cooling method increases the ventilation volume of the refuge chamber, uses air flow to take away heat to achieve a cooling effect, and the ventilation volume is adjusted with the change of temperature to maintain a constant temperature condition in the refuge chamber. The specific calculation of the air supply volume of the refuge chamber is as follows:

[0019]

[0020] Among them, T in is the air supply temperature at the air inlet of the refuge chamber, T0 is the initial surrounding rock temperature, Q is the heat generated by the indoor heat source, and h fw is the convection heat transfer coefficient of the surrounding rock inner wall, A w is the total wall area of ​​the refuge chamber, ρ a With C a are the thermophysical parameters of air, T c is the indoor ambient temperature.

[0021] Furthermore, the calculation process of surrounding rock cold storage and compressed air plus phase change composite cooling includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , wind current takes away energy Q P 、Heat absorption by the inner wall of surrounding rock Q w , Phase change seat contact surface heat absorption Qnon And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convective heat transfer condition of the outer boundary of the phase change plate and the convective heat transfer coefficient h of the outer surface of the phase change plate. mc , otherwise continue the trial calculation.

[0022] The beneficial effects of the present invention include:

[0023] (1) The present invention flexibly selects a graded cooling strategy according to the different external ambient temperatures of the refuge chamber, thereby effectively ensuring the temperature control of the refuge chamber.

[0024] (2) The present invention uses different cooling methods in a reasonable combination and proposes specific operation strategies and plans, which not only ensures the cooling effect but also takes into account the economy and practicality of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The operating mechanism of the multi-stage temperature control method for a mine refuge chamber designed for an embodiment of the present invention.

[0026] Figure 2 A calculation flow chart of phase change cooling based on a phase change plate designed for an embodiment of the present invention.

[0027] Figure 3 A calculation flow chart of phase change cooling based on a phase change seat designed for an embodiment of the present invention.

[0028] Figure 4 A calculation flow chart of phase change cooling based on phase change panels and phase change seats designed for an embodiment of the present invention.

[0029] Figure 5 A calculation flow chart of surrounding rock cold storage and compressed air plus phase change composite cooling designed for an embodiment of the present invention.

[0030] Figure 6 In the surrounding rock cold storage capacity calculation formula designed for the embodiment of the present invention, f(B i ,F O ) graph. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application.

[0032] Multi-stage temperature control method for mine refuge chamber, such as Figure 1 As shown, it includes: determining the initial surrounding rock temperature of the mine refuge chamber, determining the corresponding chamber type and corresponding temperature control strategy based on the initial surrounding rock temperature combined with the chamber refuge capacity, the chamber types include low temperature, medium-low temperature, medium temperature, medium-high temperature and high temperature, the temperature control strategy corresponding to low temperature is surrounding rock cooling, the temperature control strategy corresponding to medium-low temperature is ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium temperature is enhanced ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium-high temperature is surrounding rock cold storage and compressed air composite cooling or surrounding rock cold storage and phase change composite cooling, and the temperature control strategy corresponding to high temperature is surrounding rock cold storage and compressed air phase change composite cooling. The initial surrounding rock temperature combined with the chamber refuge capacity will serve as the decision-making condition for the refuge chamber temperature control plan, and the initial rock temperature will serve as an important decision-making basis for the plan.

[0033] The initial surrounding rock temperature is divided into several temperature sections, including: low temperature section <20℃, medium and low temperature section 20-25℃, medium temperature section 25-27℃, medium and high temperature section 27-30℃, and high temperature section >30℃. At the same time, in addition to meeting the physiological and hygienic needs of the refugees, if ventilation cooling is adopted, it is recommended that the air volume be determined according to the surrounding rock temperature range. The specific selection process is as follows:

[0034] Determine the surrounding rock parameters of the mine refuge chamber, the chamber's geometric parameters and the number of people it can accommodate, determine the thermal conductivity, density, specific heat capacity, initial surrounding rock temperature, and indoor human heat source power of the surrounding rock, and substitute the parameters into the thermal calculation method of the chamber's ambient temperature under natural convection to predict the ambient temperature changes within 96 hours. If the indoor ambient temperature is below 35°C after 96 hours, there is no need to take active cooling measures in the chamber, and the indoor compressed air supply is designed to be 100L / min per person.

[0035] If the room temperature does not exceed 35℃ after 96 hours, if it exceeds 35℃, increase the air volume and predict the indoor temperature again. When the ventilation volume reaches 300L / min per person and still cannot meet the room temperature requirements, increase the air supply volume within 500L / min per person or increase the chamber area appropriately to achieve the purpose of room temperature control.

[0036] On this basis, the relevant parameters are substituted into the thermal calculation method of the chamber ambient temperature under the cold wind state recommended in this book to predict the indoor ambient temperature and determine whether the chamber temperature control requirements are met. If not, the ventilation volume can be appropriately increased or the air supply temperature can be reduced. In addition, combined with the phase change cold storage technology, the surrounding rock cold storage + compressed air + phase change coupled temperature control system can also meet the temperature control requirements under this condition.

[0037] Specifically, (1) low-temperature mine refuge chambers (initial rock temperature <20°C) refer to refuge chambers where the room temperature does not exceed 35°C within 96 hours under natural convection conditions. In low-temperature mine refuge chambers, no additional cooling measures are required. At this time, the ventilation volume can be set to 0L / min to meet the cooling requirements.

[0038] (2) Medium-low temperature mine refuge chambers (initial rock temperature 20-25°C) refer to refuge chambers where the room temperature does not exceed 35°C within 96 hours when the compressed air supply temperature is equal to the initial surrounding rock temperature and the per capita air supply is 100L / min. Ventilation cooling or phase change cooling can be used alone to control the ambient temperature of the refuge chamber.

[0039] (3) Medium-temperature mine refuge chambers (initial rock temperature 25-27°C) refer to refuge chambers where the compressed air supply temperature is equal to the surrounding rock temperature and the per capita air supply reaches 100 L / min, which cannot meet the chamber temperature control requirements within 96 hours. However, the chamber temperature control requirements can be met by appropriately expanding the volume of the chamber or increasing the air supply. The per capita air supply range is 100-300 L / min or phase change cooling is used to control the ambient temperature of the refuge chamber.

[0040] (4) Medium-high temperature mine refuge chambers (initial rock temperature 27-30℃) refer to mine refuge chambers where the existing mine compressed air supply capacity (300-500L / mi.P) cannot meet the temperature control requirements of the chamber within 96 hours and additional cooling measures are required. In medium-high temperature mine refuge chambers, ice storage devices or chemical refrigeration devices can be used to cool the compressed air entering the survival room of the chamber to meet the temperature control requirements of the chamber within 96 hours, or the surrounding rock cold storage and phase change composite cooling can be used to cool the refuge chamber.

[0041] (5) High-temperature mine refuge chambers (initial rock temperature > 30°C) refer to refuge chambers where the compressed air entering the chamber cannot meet the 96-hour room temperature control requirements after cooling (500L / min.P). For high-temperature mine refuge chambers, cold air can be used to store cold in the surrounding rock during normal times, and cold air or phase change materials can be used to control the temperature environment of the chamber during refuge to meet the temperature control requirements of the chamber.

[0042] The surrounding rock cold storage is to determine the surrounding rock heat regulation circle, on this basis, describe the cold transfer law in the surrounding rock cold storage process, and determine the surrounding rock cold storage capacity. The surrounding rock cold storage capacity refers to the cold accumulated when the surrounding rock temperature drops within a certain depth of the chamber under the cooling effect of the wind flow. The surrounding rock cold storage capacity represents the degree of surrounding rock cold storage. Specifically,

[0043] ① Determine the radius R of the surrounding rock heat-regulating zone, which is defined as the farthest range of the temperature change inside the surrounding rock within the time τ. Since there is no unified threshold for temperature change in academia, this section assumes that the area where the temperature difference change inside the surrounding rock is greater than or equal to 0.5% is called the heat-regulating zone, that is, the boundary where the temperature difference change is equal to 0.5% is used as the boundary of the heat-regulating zone. Heat-regulating zone radius r c The fitting formula under different Biot numbers Bi is:

[0044]

[0045]

[0046] ② After determining the calculation formula of the chamber surrounding rock heat regulating circle, we can start to derive the calculation formula of the surrounding rock cold storage capacity. According to my country's "Interim Regulations on the Construction and Management of Emergency Evacuation Systems in Coal Mines" (Anjian Zongmeizhuang

[2011] No. 15), the rated protection time of the mine refuge chamber without any external support is not less than 96h. Therefore, the calculation of the surrounding rock cold storage capacity only needs to calculate the radius r of the heat regulating circle within 96h. c The temperature difference of surrounding rock cooling in the range is integrated and solved, and the integral formula is simplified to obtain the calculation formula of the cold storage capacity of the surrounding rock of the project; where C p is the specific heat capacity of the surrounding rock, ρ is the density of the surrounding rock, V C It is the volume of rock and soil within the heating circle.

[0047] Q SR =EC P ρ(T0-T f )V C ×f2(B i ,F O )

[0048] ③Parameter E represents the ratio of the cold storage capacity of the surrounding rock heat regulating circle when the cold storage time is infinite to the cold storage capacity of all temperatures within the surrounding rock heat regulating circle when the air supply temperature is assumed. It is a simplified calculation coefficient. From the expression of E, it can be seen that it is related to the thermal conductivity a and the equivalent radius r of the cavern. i and B i Related to; B i and F O They are Biot number and Fourier criterion number, respectively, and f2 is about B i and F O function, in practical engineering applications, you can refer to f(B i ,FO ) curve chart( Figure 6 ) to obtain.

[0049] The required air volume of the mine compressed air must satisfy the dual functions of oxygen supply and purification.

[0050]

[0051] If it is determined that the mine refuge chamber belongs to the medium-low temperature section, the medium temperature section or the medium-high temperature section, the cooling cost when using ventilation cooling, enhanced ventilation cooling or compressed air cooling is calculated based on the mine refuge chamber information, and compared with the cooling cost of phase change cooling in the same temperature section, and then the cooling method with lower cooling cost is selected. The mine refuge chamber information includes the geographical location of the mine and the burial depth of the refuge chamber.

[0052] The factors affecting the cooling cost of each scheme include initial investment and maintenance costs. The cooling cost of ventilation cooling, enhanced ventilation cooling or compressed air cooling is obtained through the purchase cost and maintenance cost of the equipment. The equipment includes a compressed air chamber, fan, air duct and its accessories, and terminal air outlet. The cooling cost of phase change cooling is calculated based on the real-time price of phase change materials and phase change packaging materials combined with the project situation and market prices.

[0053] In another embodiment, the phase change cooling is realized by using a phase change plate. The calculation process of the convection heat transfer condition of the outer boundary of the phase change plate includes: using a trial algorithm to calculate the air temperature. When the air itself absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w And the heat absorption of the phase change plate Q pcp When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the outer boundary of the phase change plate, that is, the air temperature T f And the convection heat transfer coefficient h of the phase change plate surface PCP , otherwise continue to calculate. Figure 2 As shown:

[0054] ① Input initial parameters and set Q a = 0, and read the phase change plate outer surface temperature T from Fluent PCP ;

[0055] ② Set the increment of ΔQ and increase the heat absorption of air Q a =Q a +ΔQ.

[0056] ③According to Q a The air temperature T can be obtained f , and then calculate the convection heat transfer coefficient h of the phase change plate surface PCP and the convection heat transfer coefficient h of the inner surface of the surrounding rock wn According to the air temperature Tf and the convective heat transfer coefficient h wn The temperature distribution of the surrounding rock and the temperature of the inner wall of the surrounding rock can be obtained, and the cooling capacity Q of the surrounding rock can be calculated. w And the phase change plate heat storage Q pcp .

[0057] ④ Determine Q a +Q w +Q pcp The relationship between the size of Q, if Q a +Q w +Q pcp If the air temperature is less than Q, it means that the air temperature is less than the actual result. Then you need to return to step ② and increase the air heat absorption to recalculate until Q a +Q w +Q pcp If it is greater than Q, the calculation stops.

[0058] ⑤Save the calculated air temperature T at this time f And the convection heat transfer coefficient h of the phase change plate surface PCP , and output to Fluent as the external boundary condition of the phase change plate.

[0059] In another embodiment, the phase change cooling is realized by using a phase change seat. The calculation process of the convection heat transfer condition of the non-contact surface of the phase change seat includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the non-contact surface of the phase change seat, that is, the air temperature T f and the convective heat transfer coefficient h non-c , otherwise continue to calculate. Figure 3 As shown:

[0060] ① Input initial parameters and set Q a = 0, and read the non-contact surface temperature T of the phase change seat from Fluent non-c .

[0061] ② Set the increment of ΔQ and increase the heat absorption of air Q a =Q a +ΔQ.

[0062] ③According to Q a The air temperature T can be obtained f , and then calculate the non-contact surface heat transfer coefficient h of the phase change seat non-c and the surrounding rock surface convection heat transfer coefficient hfw According to the air temperature T f and the convective heat transfer coefficient h wn the temperature distribution of the surrounding rock and the temperature of the inner wall surface of the surrounding rock can be obtained, and the cooling capacity Q of the surrounding rock can be calculated w and the heat storage capacity Q of the non-contact surface of the phase change seat non-c .

[0063] ④ Determine the magnitude relationship between Q a +Q w +Q non +Q non-c and Q. If Q a +Q w +Q non +Q non-c < Q, it indicates that the air temperature value at this time is less than the true result, then it is necessary to return to step ②, increase the air heat absorption and recalculate until Q a +Q w +Q non +Q non-c ≥ Q to stop the calculation.

[0064] ⑤ Save the calculated air temperature and the convective heat transfer coefficient h of the non-contact surface of the phase change seat at this time non-c , and output it to Fluent as the outer boundary condition of the non-contact surface of the phase change seat.

[0065] In another embodiment, the phase change cooling is realized by a phase change plate and a phase change seat. Based on the UDF calculation program flow of the coupled cooling system of the phase change plate and the phase change seat, the following principles are followed: The heat transfer calculation processes of the phase change plate, the surrounding rock, and the indoor heat source air are compiled into corresponding UDF programs, and then the calculated air temperature T f and the convective heat transfer coefficient h non-c are substituted into the calculation of the non-contact surface of the phase change seat in the form of the third type of outer boundary condition. The calculation process of the heat transfer of the phase change plate and the phase change seat includes: using the trial method to calculate the air temperature. When the sum of the heat absorption Q of the air itself a , the heat absorption Q of the inner wall surface of the surrounding rock w , the heat absorption Q of the phase change plate PCP , the heat absorption Q of the contact surface of the phase change seat non and the heat absorption Q of the non-contact surface of the phase change seat non-c is equal to the heat production Q of the indoor heat source, the air temperature is the correct solution. At this time, the final result is output as the convective heat transfer condition and h of the outer boundary of the non-contact surface of the phase change seat, otherwise continue the trial calculation. Specifically, as Figure 4 shown:[[]]

[0066] ① Input the initial parameters, set Q a = 0, and read the outer surface temperature T of the non-contact surface of the phase change seat from Fluent non-c。

[0067] ② Set the increment of ΔQ and increase the heat absorption Q of the air a = Q a + ΔQ.

[0068] ③ According to Q a , the air temperature T can be obtained f , and then the convective heat transfer coefficient h on the outer surface of the phase change plate is calculated PCP , the convective heat transfer coefficient h on the non-contact surface of the phase change seat non-c and the convective heat transfer coefficient h on the surrounding rock surface fw . According to the air temperature T f and the convective heat transfer coefficient, the temperature distribution of the surrounding rock and the temperature distribution of the phase change plate can be obtained, and the heat release Q of the surrounding rock w , the heat storage Q of the phase change plate PCP and the heat storage Q on the non-contact surface of the phase change seat can be calculated non-c .

[0069] ④ Determine the magnitude relationship between Q a + Q w + Q non + Q non-c + Q PCP and Q. If Q a + Q w + Q non + Q non-c + Q PCP < Q, it means that the air temperature value is less than the true result at this time, and it is necessary to return to step ② to increase the air heat absorption and recalculate until Q a + Q w + Q non + Q non-c + Q PCP ≥ Q to stop the calculation.

[0070] In another embodiment, the ventilation and cooling method achieves the cooling effect by increasing the ventilation volume of the refuge chamber and using the air flow to carry away heat, and the ventilation volume is adjusted according to the change of temperature to maintain the constant temperature condition of the refuge chamber. The specific calculation of the air supply volume of the refuge chamber is as follows:

[0071]

[0072] where, T in is the air supply temperature at the air inlet in the refuge chamber, T0 is the initial surrounding rock temperature, Q is the heat generation of the indoor heat source, h fw is the convective heat transfer coefficient on the inner wall surface of the surrounding rock, A w is the total inner wall surface area of the refuge chamber, ρ a and C a are the thermal physical properties of the air respectively, T cis the indoor environmental temperature.

[0073] In another embodiment, the calculation process of the surrounding rock cold storage and compressed air phase change composite cooling includes: using the trial method to calculate the air temperature. When the sum of the heat absorbed by the air itself Q a , the energy carried away by the air current Q P , the heat absorbed by the inner wall surface of the surrounding rock Q w , the heat absorbed by the contact surface of the phase change seat Q non and the heat absorbed by the non-contact surface of the phase change seat Q non-c is equal to the heat generated by the indoor heat source Q, the air temperature is the correct solution. At this time, the final result output is the convective heat transfer condition at the outer boundary of the phase change plate and the convective heat transfer coefficient h mc , otherwise continue the trial calculation. Specifically, as Figure 5 shown:

[0074] ① Input the initial parameters, set Q a =0, and read the outer surface temperature T non-c of the non-contact surface of the phase change seat from Fluent.

[0075] 2) Set the increment of ΔQ = 0.1W, and increase the heat absorption Q a of the air = Q a +ΔQ.

[0076] 3) According to Q a , the air temperature T f can be obtained, and then the convective heat transfer coefficient h fPCP and h fw are calculated. According to the air temperature T f and the convective heat transfer coefficient h fw , the temperature distribution of the surrounding rock and the inner wall surface temperature of the surrounding rock can be obtained, and the heat storage Q w of the surrounding rock and the heat storage Q non-c of the non-contact surface of the phase change seat can be calculated.

[0077] 4) Determine the magnitude relationship between Q P +Q a +Q w +Q non +Q non-c and Q. If Q P +Q a +Q w +Q non +Q non-c <Q, it means that the air temperature value is less than the true result at this time, and it is necessary to return to step 2), increase the air heat absorption and recalculate until Q P +Q a +Q w +Q non +Q non-c ≥Q to stop the calculation.

[0078] 5) Save the calculated air temperature T at this time f and the convective heat transfer coefficient h fPCM Output to Fluent as the outer boundary condition of the non-contact surface of the phase change seat.

[0079] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A multi-stage temperature control method for a mine refuge chamber, characterized in that: include: Determine the initial surrounding rock temperature of the mine refuge chamber, and determine the corresponding chamber type and corresponding temperature control strategy based on the initial surrounding rock temperature and the chamber refuge capacity. The chamber types include low temperature, medium-low temperature, medium temperature, medium-high temperature and high temperature. The temperature control strategy corresponding to low temperature is surrounding rock cooling, the temperature control strategy corresponding to medium-low temperature is ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium temperature is enhanced ventilation cooling or phase change cooling, the temperature control strategy corresponding to medium-high temperature is surrounding rock cold storage and compressed air composite cooling or surrounding rock cold storage and phase change composite cooling, and the temperature control strategy corresponding to high temperature is surrounding rock cold storage and compressed air phase change composite cooling.

2. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The calculation process of surrounding rock cold storage and compressed air plus phase change composite cooling includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , wind current takes away energy Q P 、Heat absorption by the inner wall of surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convective heat transfer condition of the outer boundary of the phase change plate and the convective heat transfer coefficient h on the surface of the phase change plate. mc , otherwise continue the trial calculation.

3. The multi-stage temperature control method for a mine refuge chamber according to claim 2, characterized in that: The calculation process of surrounding rock cold storage and compressed air plus phase change composite cooling includes: a. Input initial parameters and set Q a = 0, and read the non-contact surface temperature T of the phase change seat from Fluent non-c ; b. Set the increment of ΔQ = 0.1W and increase the heat absorption of the air Q a =Q a +ΔQ; c. According to Q a , the air temperature T can be obtained f , and then calculate the surface convection heat transfer coefficient h of the phase change seat fPCP and the convection heat transfer coefficient h of the inner wall of the surrounding rock fw ; According to the air temperature T f and the convection heat transfer coefficient h of the inner wall of the surrounding rock fw The temperature distribution of the surrounding rock and the temperature of the inner wall of the surrounding rock can be obtained, and the heat storage capacity Q of the surrounding rock can be calculated. w And the heat storage Q of the non-contact surface of the phase change seat non-c ; d. Determine Q P +Q a +Q w +Q non +Q non-c The magnitude relationship with the magnitude of Q. If Q P +Q a +Q w +Q non +Q non-c < Q, it indicates that the air temperature value is less than the true result at this time. Then, it is necessary to return to step 2), increase the air heat absorption and recalculate until Q P +Q a +Q w +Q non +Q non-c ≥ Q to stop the calculation; e. Save the calculated air temperature T at this time f and the convection heat transfer coefficient h of the phase change seat surface fPCP Output to Fluent as the outer boundary condition of the phase change seat.

4. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: If it is determined that the mine refuge chamber belongs to the medium-low temperature section, the medium temperature section or the medium-high temperature section, the cooling cost when using ventilation cooling, enhanced ventilation cooling or compressed air cooling is calculated based on the mine refuge chamber information, and compared with the cooling cost of phase change cooling in the same temperature section, and then the cooling method with lower cooling cost is selected. The mine refuge chamber information includes the geographical location of the mine and the burial depth of the refuge chamber.

5. The multi-stage temperature control method for a mine refuge chamber according to claim 4, characterized in that: The factors affecting the cooling cost of each scheme include initial investment and maintenance costs. The cooling cost of ventilation cooling, enhanced ventilation cooling or compressed air cooling is obtained through the purchase cost and maintenance cost of the equipment. The equipment includes a compressed air chamber, fan, air duct and its accessories, and terminal air outlet. The cooling cost of phase change cooling is calculated based on the real-time price of phase change materials and phase change packaging materials combined with the project situation and market prices.

6. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The phase change cooling is realized by using a phase change plate. The calculation process of the convection heat transfer condition at the outer boundary of the phase change plate includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w And the heat absorption of the phase change plate Q pcp When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the outer boundary of the phase change plate, that is, the air temperature T f and the convection heat transfer coefficient h of the phase change seat surface PCP , otherwise continue the trial calculation.

7. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The phase change cooling is realized by using a phase change seat. The calculation process of the convection heat transfer condition of the non-contact surface of the phase change seat includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convection heat transfer condition of the non-contact surface of the phase change seat, that is, the air temperature T f and the non-contact surface flow heat transfer coefficient h of the phase change seat non-c , otherwise continue the trial calculation.

8. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The phase change cooling is realized by using phase change plate and phase change seat, and the air temperature is calculated by trial and error algorithm. When the air absorbs heat Q a , the heat absorbed by the inner wall of the surrounding rock Q w , Phase change plate heat absorption Q PCP , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the heat generated by the indoor heat source Q, the air temperature is a positive answer. At this time, the final output result is the convective heat transfer condition and h of the outer boundary of the non-contact surface of the phase change seat, otherwise continue the trial calculation.

9. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The ventilation and cooling method increases the ventilation volume of the refuge chamber and uses air flow to take away heat to achieve a cooling effect. The ventilation volume is adjusted as the temperature changes to maintain a constant temperature in the refuge chamber. The specific air supply volume of the refuge chamber is calculated as follows: Among them, T in is the air supply temperature at the air inlet of the refuge chamber, T0 is the initial surrounding rock temperature, Q is the heat generated by the indoor heat source, h fw is the convection heat transfer coefficient of the inner wall, A w is the total wall area of ​​the refuge chamber, ρ a With C a are the thermophysical parameters of air, T c is the indoor ambient temperature.

10. The multi-stage temperature control method for a mine refuge chamber according to claim 1, characterized in that: The calculation process of the pressure-wind phase change composite cooling includes: using a trial algorithm to calculate the air temperature, when the air itself absorbs heat Q a , wind current takes away energy Q P 、Heat absorption by the inner wall of surrounding rock Q w , Phase change seat contact surface heat absorption Q non And the heat absorption Q of the non-contact surface of the phase change seat non-c When the sum is equal to the indoor heat source heat generation Q, the air temperature is a positive solution. At this time, the final output result is the convective heat transfer condition of the outer boundary of the phase change plate and the convective heat transfer coefficient h on the surface of the phase change plate. mc , otherwise continue the trial calculation.

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