CN110030027A - A kind of mine air cooling system and method based on thermostat layer cold water source - Google Patents

Abstract

The invention discloses a mine air flow cooling system and method based on a constant temperature layer cold water source, comprising a constant temperature layer cold water source, a water inlet pipeline, a water pump, a heat exchanger, an air inlet air duct, a fan, an air outlet air duct and a return water pipeline The cold water source of the constant temperature layer is connected with the water inlet pipeline and one end of the heat exchanger in turn through the water pump, the air inlet air duct is connected with the fan and one end of the heat exchanger in turn, and the return water pipeline and the air outlet air duct are respectively connected with the heat exchanger; The constant temperature water flow of the constant temperature layer cold water source that meets the needs of underground ventilation and cooling is directly used as the refrigerant, and the heat exchange occurs with the ventilation air flow through the heat exchanger to achieve the purpose of reducing the air temperature, eliminating the need for the compressor refrigeration part and reducing the equipment. And the cost of electricity, making the entire air flow cooling system simpler, and the layout is more flexible and diverse.

Description

A mine air flow cooling system and method based on a constant temperature layer cold water source

technical field

The invention belongs to the field of ventilation and cooling in mines or other civil underground projects, and in particular relates to a mine air flow cooling system and method based on a constant temperature layer cold water source.

Background technique

The occurrence of high temperature heat damage in mines has seriously affected the development of the mining industry. Countries in the world with high temperature mines started research on mine cooling technology 90 years ago. In the 1980s, refrigeration cooling has become the main technical means of cooling deep mines. Refrigeration and dehumidification are necessary in deep and medium-depth mining, especially mechanized and high-temperature mines. The simplest is the application of smaller portable mobile coolers, large central refrigeration systems are becoming more common. Deep mining areas in more than 15 countries must rely on refrigeration systems, most notably the 3.7km deep gold mine in South Africa. In Europe, all deep coal mining has air conditioning systems.

In 1915, the world's first mine air-conditioning system was established in the Moraujorihe gold mine in Brazil, and a centralized refrigeration station was established on the ground. The mining depth is 2000m, the temperature of the surrounding rock is 50℃, the piston refrigerator is used, the motor is 530kW, the refrigerant is R-11, and the cooling capacity is 1744kW. The spray air cooler is installed on the ground, and the cooling air volume is ^2300m3 /min. Cooling from 30°C to 6°C; Britain is the first country in the world to implement air-conditioning technology underground. In 1923, the Pendleton Coal Mine in the United Kingdom was the first to install a refrigerator in the mining area to cool the wind flow on the coal mining face. Germany first started in 1924 in the Radlod Coal Mine, with a mining depth of 968m and a surrounding rock temperature of 44°C. A refrigerator was installed on the ground, a piston refrigerator was used, the refrigerant was R-11, and the motor power was 150kW. , the cooling capacity is 581kW, and the air cooler is installed underground, which can reduce the temperature of 7200m ³ /min air volume from 22.5 ℃ to 19.5 ℃. The first installation of large-scale air flow cooling equipment underground was the Loberg Mine in 1953. There are 32 pairs of mines in Germany, and 28 pairs of mines have been cooled by air conditioners. The total cooling capacity in 1986 reached 91.4MW, and in September 1993 it was 256MW. Australia also uses a refrigeration system to pre-cool the air entering the main air shaft. The 25MW refrigeration system established at the Isa Copper Mine can cool the air from 26°C to 14.6°C, and the cooling rate of the air is 580kg/s, which is equivalent to every day. Makes 6300t of ice. Canadian mines have invested heavily in the management of large-capacity ventilation and refrigeration technologies. CapitaMine spent 21 million Canadian dollars to install a 12MW refrigeration system and upgrade the ventilation system to improve the harsh conditions of 35°C temperature at a depth of 3000m; Lanrongde Mine installed it in 2002 for its 2000m, 38°C conditions The first 5MW mechanical cooling system in Canada was built, and in 2004 an additional $6.6 million was invested to upgrade it to 12MW and moved to the surface; it will be upgraded to 19MW soon. The Soviet Union, Japan and other countries began to apply refrigeration in the 1970s. Now, the scale of foreign mine air conditioning and refrigeration is getting bigger and bigger, and it is developing rapidly. The total cooling capacity of Japanese mines from 1975 to 1985 reached 4528MW.

In the 1960s, large-scale mine centralized air conditioning began in South Africa. At present, the world's largest mine air-conditioning and refrigeration capacity is the South African gold mine. 44 pairs of mines in the country have installed refrigerators for cooling. In November 1985, the South African gold mine sent ice into the mine, using the ice's dissolution to absorb heat, To cool the cooling water in the air cooler, its refrigeration system has a capacity of 628MW. In 1988, the total refrigeration capacity has exceeded 500MW, with an average of more than 11.4MW per mine. The Mponeng gold mine in South Africa is buried at a depth of 3.5km and the temperature reaches about 60°C. The future mining depth of the mine will reach a depth of 5km, and the main shaft will be extended to 3.2km. Ventilation relies on surface high-power fans that send air into one or two shafts to guide air circulation. The air temperature is cooled to around 32°C through the use of ventilation and freezing fillings. The concrete waste rock mixture is cooled before being pumped to the goaf, cooling the remaining ore body.

The use of refrigeration technology in my country began in 1964. At that time, the Fushun Branch of the General Research Institute of Coal Science introduced a Soviet-made 4F10 piston chiller with a cooling capacity of 58kW. The local cooling test was carried out in Jiulonggang Mine in Huainan. At the same time, two types of surface type and spray type were used type of air cooler. On this basis, in 1967, the Fushun Branch of the General Institute of Coal Science and the Changsha Institute of Mining and Metallurgy jointly developed the JKT-20 mining air cooler with a cooling capacity of 70kW. In 1979, Fushun Branch and Wuhan Refrigerator Factory jointly developed the JKT-70 mining chiller with a cooling capacity of 235kW, which was used to cool the tunnel face. In 1984, my country's first underground centralized air-conditioning system was established in Xinwensun Village Mine. The system was designed by Fushun Branch with a designed cooling capacity of 2324kW. Four sets of Ⅱ-JB50×0 centrifugal chillers were used. is 581kW. When the mining depth of the mine entered the level of -800m, due to the difficulty of removing condensation heat underground, it was changed to a ground centralized air-conditioning system in 1994. Combined with the domestic LSLGF2-25 chiller, the total cooling capacity is 5440kW, which is also the first ground centralized refrigeration and air conditioning system in my country.

With the expansion of my country's industrial scale and the rapid increase in demand for ore, the depth of mines is increasing rapidly, and geothermal hazards are becoming more and more serious. In the control of geothermal hazards in my country, due to cost considerations, non-artificial cooling methods have been adopted in the past, such as increasing the air flow rate and taking away more heat; using the original goaf of the mine as a cooling energy reserve, The convenient empty area can store water inside. In winter, when the external cold air flows in, the water condenses into ice and stores the cold energy; in summer, when the external hot air enters, it exchanges heat with the ice and the cold rock wall, and the air flow is cooled down. With the increasing seriousness of geothermal hazards, the forced artificial cooling method will also become the inevitable result of deep well heat damage control in my country. However, compared with foreign countries, the conditions of mines in my country are more severe, and the cost of geothermal cooling is the key to the success of this technology. Although some preliminary studies have been carried out in individual mines, most of the refrigeration technologies used are traditional mechanical refrigeration methods. The refrigeration efficiency of the core components and the heat exchange efficiency between the cold end and the hot end are low, resulting in the high cost of mine geothermal control. Many ordinary Metal mines are unbearable. Therefore, a mine air flow cooling system based on a constant temperature layer water source is proposed. The system is simple in composition, easy to use, and greatly reduces the cost of mine cooling, which is worthy of promotion.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present invention provides a mine air flow cooling system and method based on a constant temperature layer cold water source, which saves the compressor refrigeration part, reduces equipment and electricity costs, and makes the entire air flow cooling system simpler. The layout is also more flexible and diverse.

The invention provides a mine air flow cooling system based on a constant temperature layer cold water source, comprising: a constant temperature layer cold water source, a water inlet pipeline, a water pump, a heat exchanger, an air inlet air duct, a fan, an air outlet air duct, a return water pipeline, The constant temperature layer cold water source is sequentially connected to the water inlet pipeline and one end of the heat exchanger through a water pump, the air inlet duct is sequentially connected to the fan and one end of the heat exchanger, and the return water pipeline and the air outlet duct are respectively connected to the end of the heat exchanger. heat exchanger connection.

The temperature of the cold water source in the constant temperature layer is lower than 20°C.

The constant temperature layer cold water source can also be changed to surface low temperature water source and underground low temperature water source. The surface low temperature water source can include surface rivers, spring water, etc. In addition to the constant temperature layer water source, the underground low temperature water source also includes low temperature rock formations in other regions that can meet the needs of wind cooling. water, etc.

The working principle of a mine air flow cooling system based on a constant temperature layer cold water source provided by the present invention is as follows:

Combined with the principle of thermodynamic transfer, the parameters of a mine air flow cooling system based on a constant temperature layer cold water source are calculated:

(1) The cooling capacity of the tunneling face is calculated as follows:

Q _l =cMΔt

In the formula: Q _l - cooling capacity, kW;

c——the average specific heat capacity of air, kJ/Kg ℃;

M——Air volume in standard state, Kg/s;

Δt——air temperature difference, Δt=t ₁ -t ₂ ;

t ₁ — ambient air temperature, °C;

t ₂ — the temperature to which the air is required to drop, °C;

(2) The heat exchange area of the heat exchanger is calculated as follows:

Where: α——Convection heat transfer coefficient, W/(m2·℃);

Δt _d ——logarithmic mean temperature difference;

t ₁ — air inlet temperature, °C;

t ₂ — air outlet temperature, °C;

t ₃ ——cold water inlet temperature, °C;

t ₄ — cold water outlet temperature, °C;

(3) The required flow of cooling water is calculated as follows:

In the formula: Q _l - the required heat exchange, W;

c _{w ——specific} heat capacity of water, J/(Kg ℃);

Δt _w — temperature difference of cooling water, °C;

A mine air flow cooling method based on a constant temperature layer cold water source, using the aforementioned mine air cooling system based on a constant temperature layer cold water source, comprising the following steps:

Step 1: start the water pump to transport the constant temperature water flow of the constant temperature layer cold water source to the heat exchanger through the water inlet pipeline as a refrigerant;

Step 2: start the fan to transport the mine ventilation air flow to be cooled to the heat exchanger through the air inlet air duct and conduct heat exchange with the constant temperature water flow of the coolant in the heat exchanger to form a cooling air flow and a heating water flow;

Step 3: The cooling air flow is transported from the outlet air duct to the area to be cooled, and the heating water flow is transported by the return water pipeline to the nearby tunnels and ditches or other drainage and water systems.

Beneficial effects of the mine air flow cooling system and method based on the constant temperature layer cold water source of the present invention: The mine air flow cooling system based on the constant temperature layer cold water source provided by the present invention uses the constant temperature layer water source directly as the refrigerant, and passes through the heat exchanger. Heat exchange with the wind flow, so as to achieve the purpose of reducing the wind temperature. At the same time, the system eliminates the refrigeration part of the compressor, reduces the cost of equipment and electricity, makes the entire air flow cooling system simpler, and the layout is more flexible and diverse.

For mines with global ventilation and cooling requirements, before the fan sends the natural air flow into the well, the surface river or spring water can be selected as the coolant, and the heat exchange between the low-temperature water flow and the conveying air flow is carried out through the heat exchanger, or when the air flow passes through the constant temperature layer When the water source is low temperature, the heat exchange is carried out with the low temperature water inflow of the constant temperature layer through the heat exchanger to reduce the initial temperature of the air flow in front of each excavation work in the mine, and then reduce the temperature of the air flow when it is conveyed to each excavation work face in the mine, so as to achieve the overall ventilation and cooling effect of the mine. Purpose. For mines that use this system for global ventilation and cooling, the cooling air volume is large and the wind speed is high. Heat exchange equipment with larger heat exchange area and high heat exchange efficiency can be selected, or multiple heat exchange equipment can be used in series. At the same time, the heated water flow after heat exchange with the conveying air flow can be discharged into rivers or springs again, or directly transported to other water systems in the mine.

For the mining face or other underground engineering structures that have local ventilation and cooling requirements in the mine, the low-temperature rock formation that is closer to the cooling area and can meet the local ventilation and cooling requirements of the mining face or other engineering structures can be used as the coolant. The water pump transports the low-temperature water flow to the air flow cooling system near the excavation face or other engineering structures for local ventilation and air flow cooling in the mine, or for the case where the local ventilation air duct passes through the low-temperature rock gushing area, the air flow cooling system can be directly arranged at the low temperature. The water inflow area of the rock formation is directly cooled by the air flow through the air flow cooling system, and then transported to the local cooling area such as the mining face to meet the local ventilation and cooling requirements of the mine. The heated water flow after heat exchange with the conveying air flow can be temporarily pumped to the nearby roadways and ditches or other drainage and water systems.

Description of drawings

1 is a schematic diagram of a mine air flow cooling system based on a constant temperature layer cold water source of the present invention;

Figure 2 is a schematic diagram of the implementation process of local ventilation and air flow cooling in the excavation face of a mine roadway;

in

1 air inlet air duct, 2 fan, 3 heat exchanger, 4 constant temperature layer cold water source, 5 water pump, 6 water inlet pipeline, 7 air outlet air duct, 8 return water pipeline

Detailed ways

The present invention will be further described in detail below in conjunction with the embodiments.

As shown in Figure 1, a mine air flow cooling system based on a constant temperature layer cold water source includes: a constant temperature layer cold water source 4, a water inlet pipeline 6, a water pump 5, a heat exchanger 3, an air inlet air duct 1, a fan 2, and an air outlet The air duct 7, the return water pipeline 8, the cold water source 4 of the constant temperature layer are connected to the water inlet pipeline 6 and one end of the heat exchanger 3 in turn through the water pump 5, and the air inlet air duct 1 is sequentially connected to the One end of the fan 2 and the heat exchanger 3 are connected to each other, and the water return pipeline 8 and the air outlet duct 7 are respectively connected to the heat exchanger 3 .

Taking the local ventilation airflow cooling of the tunneling face of a mine as an example, the specific implementation process of the mine ventilation airflow cooling based on the constant temperature layer cold water source is described. Figure 2 is a schematic diagram of the implementation process of local ventilation and air flow cooling in the tunneling working face of a mine. A kind of mine airflow cooling system based on a constant temperature layer cold water source provided by the present invention is used to ventilate and cool the tunnel tunneling working face, and the constant temperature layer water flow The ventilation air flow is transported by the cable shaft 9 to the ventilation chamber near the tunnel excavation working face, and the air inlet duct 1 is sequentially connected with the fan 2 and the heat exchanger 3 arranged at the ventilation chamber, so The water inlet pipeline 6 and the return water pipeline 8 are connected with the heat exchanger 3, one end of the air outlet duct 7 is connected with the other end of the heat exchanger 3, and the other end of the air outlet duct 7 is connected. Connected to the roadway excavation face 10 .

A mine air flow cooling method based on a constant temperature layer cold water source of the present invention is carried out according to the following steps:

Step 1: The ventilation air flow and the water flow of the constant temperature layer are transported from the cable well 9 to the ventilation chamber near the tunnel excavation face;

Step 2: The constant temperature water is transported to the heat exchanger 3 by the water pump 5 through the water inlet pipeline 6 as a refrigerant;

Step 3: The air flow is transported to the heat exchanger 3 by the fan 2 through the air inlet air duct 1 to carry out heat exchange with the constant temperature water flow to form a cooling air flow and a heating water flow;

Step 4: The cooling air flow is transported to the tunnel excavation working face through the air outlet duct 7 to carry out ventilation and cooling on the working face 10, and the heating water flow is transported by the return water pipeline 8 through the cable well to the nearby tunnel ditch or other drainage and water system.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should Modifications or equivalent substitutions are made to the specific embodiments, and any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention shall all be included in the scope of the present claims.

Claims (6)

1. a mine air flow cooling system based on a constant temperature layer cold water source is characterized in that: comprising: a constant temperature layer cold water source, a water inlet pipeline, a water pump, a heat exchanger, an air inlet air duct, a fan, an air outlet air duct, a water return pipe The cold water source of the constant temperature layer is connected to the water inlet pipeline and one end of the heat exchanger in turn through the water pump, the air inlet air duct is connected to the fan and one end of the heat exchanger in sequence, and the return water pipeline and the air outlet air duct are connected in turn. connected to the heat exchanger respectively. 2 . The mine air flow cooling system based on a constant temperature layer cold water source according to claim 1 , wherein the temperature of the constant temperature layer cold water source is lower than 20° C. 3 . 3. A mine air flow cooling system based on a constant temperature layer cold water source according to claim 1, wherein the constant temperature layer cold water source can also be changed to a surface low temperature water source and an underground low temperature water source, and the surface low temperature water source can include the surface Rivers, springs, etc. In addition to the constant temperature layer water source, the underground low-temperature water source also includes the low-temperature rock formation in other areas that can meet the needs of wind cooling. 4. a mine air flow cooling system based on a constant temperature layer cold water source according to claim 1, is characterized in that: the heat exchange area of the heat exchanger is calculated as follows: (1) The cooling capacity of the tunneling face is calculated as follows: Q _l =cMΔt In the formula: Q _l - cooling capacity, kW; c——the average specific heat capacity of air, kJ/Kg ℃; M——Air volume in standard state, Kg/s; Δt——air temperature difference, Δt=t ₁ -t ₂ ; t ₁ — ambient air temperature, °C; t ₂ — the temperature to which the air is required to drop, °C; (2) The heat exchange area of the heat exchanger is calculated as follows: Where: α——Convection heat transfer coefficient, W/(m2·℃); Δt _d ——logarithmic mean temperature difference; t ₁ — air inlet temperature, °C; t ₂ — air outlet temperature, °C; t ₃ ——cold water inlet temperature, °C; t ₄ — cold water outlet temperature, °C. 5. a kind of mine air flow cooling system based on constant temperature layer cold water source according to claim 1, is characterized in that: the required flow rate of described cooling water is calculated as follows: In the formula: Q _l - the required heat exchange, W; c _{w ——specific} heat capacity of water, J/(Kg ℃); Δt _w — temperature difference of cooling water, °C. 6. A method for mine air flow cooling based on a mine air flow cooling system based on a constant temperature layer cold water source according to any one of claims 1 to 5, characterized in that: comprising the following steps: Step 1: start the water pump to transport the constant temperature water flow of the cold water source of the constant temperature layer to the heat exchanger through the water inlet pipeline as a refrigerant; Step 2: start the fan to transport the mine ventilation air flow to be cooled to the heat exchanger through the air inlet air duct to conduct heat exchange with the constant temperature water flow of the carrier coolant in the heat exchanger to form a cooling air flow and a heating water flow; Step 3: The cooling air flow is transported from the outlet air duct to the area to be cooled, and the heating water flow is transported by the return water pipeline to the nearby tunnels and ditches or other drainage and water systems.