An integrated mine local cooling system based on gradient enthalpy exergy module

Abstract

The present invention discloses a local cooling system for mines based on gradient enthalpy exergy module integration, including several refrigeration subsystems and air coolers; several refrigeration subsystems are connected in parallel and include condensers, expansion valves, evaporators and compressors that are connected in series to form a closed loop, and the condensers are connected to cold sources; the air coolers are connected in series and are respectively connected to evaporators; there is a temperature difference between the air flow inlet of each air cooler and the inlet of the shell channel, and the temperature difference between two adjacent air coolers is equal or unequal; the air outlet of the front air cooler is connected to a wind tube and the air outlet of the wind tube faces the coal mining working face, and the air inlet of the rear air cooler is connected to an air supply device. The present invention can achieve local cooling of the mine, provide protection for the health improvement of workers, multiple air coolers are connected in series, multiple refrigeration subsystems are connected in series, gradient enthalpy exergy can be achieved, the temperature difference range of air coolers at all levels is reduced, and the enthalpy exergy efficiency is improved, thereby making the single refrigeration subsystem and air cooler modularly processed, and convenient for operation and management.

Description

Technical Field

[0001] The present invention relates to the field of mine cooling technology, and in particular to a method based on gradient enthalpy. Modular integrated mine local cooling system. Background Art

[0002] Due to the rapid growth of my country's economy, the demand for energy is increasing, especially the gap in energy demand mainly based on coal will continue to increase, and the number and output of mine mining will continue to increase. Therefore, as time goes by, the mining of mineral resources has become less and less in the shallow part, which has led to the mining of mines gradually developing in the deep direction, and the depth of coal mining and excavation faces in coal mines has also continued to deepen. Therefore, the problem of high temperature in mines has become inevitable, and mine heat damage has become another major disaster after the five major disasters of gas, roof, dust, water and fire. Therefore, it is of great significance to study the cooling technology of high-temperature mines.

[0003] It is predicted that among the total coal reserves in my country, 73.2% of the coal reserves are buried at a depth of more than 1,000 meters. As the mining depth increases, the number of mines with a depth of more than 800 meters is increasing. As the depth and intensity of coal mining in my country gradually increase, and the trend of accelerated increase is showing, the mining depth of mines in East China generally enters below 600m. Therefore, with the increase in depth, the impact of temperature increase on mine production becomes more and more serious. In a few mines, the temperature at the underground mining site is as high as 38°C, or even higher.

[0004] Because the temperature at the deep working place of the mine increases, the work efficiency of the personnel working underground will be reduced, the service life of the equipment will be shortened, and the health of the staff will be seriously affected. According to domestic and foreign research statistics, for every 1°C increase in temperature, the efficiency of mine production will decrease by 6% to 8%, the medical expenses of miners will increase by 8% to 10%, and the failure rate of electromechanical equipment underground will increase by more than 1 times; according to the latest statistics from South Africa, the probability of death from heat stroke among workers working under the condition of wet bulb temperature of 32.8 to 33.8°C is 0.57 per thousand. According to Article 102 of the Coal Mine Safety Regulations, it is also clearly stipulated that the air temperature of the mining face of the production mine shall not exceed 26°C. When the air temperature exceeds the specified temperature, the working hours of the staff at the place where the temperature exceeds the specified temperature must be shortened, and high temperature health care treatment must be given; when the air temperature of the mining face exceeds 30°C, the operation must be stopped. In fact, the maximum temperature of many mines below 500m reaches 40°C, which seriously affects the health and work efficiency of workers.

[0005] At present, the mining faces of high-temperature mines basically adopt measures such as increasing air volume, reducing heat dissipation of mechanical equipment and shortening operation time, but they cannot effectively solve the problem of geothermal disasters. The return air temperature of the mining face in the high-temperature area deep in the mine is 32-34°C, and can reach 33-35°C in summer. Workers working on site have suffered from heat stroke. The health of workers and the safety of production on site are seriously endangered by geothermal disasters, resulting in the forced suspension of mining work. The technology of heat damage control in deep mines has become a crucial technology for the stable development of mining areas.

[0006] From this, we can imagine that similar problems also exist in the refrigeration system and central air-conditioning system of the prior art. Summary of the invention

[0007] The purpose of the present invention is to provide a method based on gradient enthalpy to solve the following deficiencies in the prior art: Modular integrated mine local cooling system, proposed gradient enthalpy Theoretical, considering the enthalpy of the air cooler Different, using the principle of grade difference, establish gradient enthalpy Methods of utilizing cold energy to increase enthalpy Based on the above theory, the unit is modularized to calculate the enthalpy of each air. Carry out differential adjustment to achieve the purpose of improving efficiency and increasing the capacity of cooling; to achieve local cooling in the mine and provide protection for the health of workers and the improvement of work efficiency.

[0008] To achieve the above object, the present invention adopts the following technical solution:

[0009] A gradient enthalpy A local cooling system for a mine, comprising a plurality of expandable refrigeration subsystems and a plurality of expandable air coolers adapted to the refrigeration subsystems and arranged in the mine tunnel; the plurality of refrigeration subsystems respectively comprise a condenser, an expansion valve, an evaporator and a compressor which are sequentially connected in series to form a closed loop, the plurality of refrigeration subsystems are arranged in parallel and the condenser of each refrigeration subsystem is connected to a cold source; the plurality of air coolers are connected in series, the shell-side channel inlets of the plurality of air coolers are respectively connected to the shell-side channel outlets of the evaporator in the adapted refrigeration subsystem, the shell-side channel outlets of the plurality of air coolers are respectively connected to the shell-side channel inlets of the evaporator in the adapted refrigeration subsystem to cool down the airflow passing through the air cooler; a temperature difference is generated between the airflow inlet of each air cooler and the inlet of the shell-side channel, and the temperature difference between two adjacent air coolers is equal or unequal; the air outlet end of the frontmost air cooler is connected to a wind tube and the air outlet of the wind tube faces the coal mining working face, and the air inlet end of the rearmost air cooler is connected to an air supply device.

[0010] As an improvement to the above technical solution, among the two adjacent air coolers, the shell side channel inlet temperature of the air cooler close to the coal mining working face is lower than the shell side channel inlet temperature of the air cooler far from the coal mining working face.

[0011] As an improvement to the above technical solution, the cold source is provided with an outlet pipe and an inlet channel; the inlet of the shell-side channel of the condenser is connected to the outlet pipe of the cold source, and the outlet of the shell-side channel of the condenser is connected to the inlet channel of the cold source to form a water circulation closed loop. The water circulation closed loop can promote the rational use of the cooling capacity of the entire system and achieve water conservation.

[0012] As an improvement to the above technical solution, a first cooling water pump is provided on the outlet pipe of the cold source to provide cooling to the condensers of the refrigeration subsystems; a second cooling water pump is provided on the pipe connecting the outlet of the evaporator shell-side channel and the inlet of the air cooler shell-side channel. The second cooling water pump can promote the flow of cooling between the evaporator and the air cooler.

[0013] As an improvement to the above technical solution, the air supply device is a fan; the condenser is a water-cooled condenser, and the evaporator is a water-cooled evaporator.

[0014] The basic working principle of the present invention is: the working medium completes the circulation in the refrigeration subsystem composed of the compressor, condenser, expansion valve and evaporator. The working medium in the condenser lowers the temperature by heat exchange with the cooling water pool, and the working medium in the evaporator exchanges heat with the chilled water, thereby absorbing the heat of the chilled water. The chilled water flows through the shell side of the air cooler to reduce the local temperature in the mine. After the chilled water exchanges heat with the air, it is circulated to the evaporator by the chilled water pump for heat exchange.

[0015] The present invention is based on the gradient enthalpy The local cooling system of the mine is to set up multiple air coolers in series on the same air duct to achieve gradient enthalpy And cold energy gradient utilization. Each air cooler and refrigeration subsystem is modularized, and the number of air coolers in operation can be flexibly adjusted according to actual needs, so that the actual temperature can be lowered to a lower level. Make the system more stable and reliable. Even if one of the air coolers fails to work properly, the other air coolers can still reduce the air to the required temperature.

[0016] Compared with the prior art, the present invention has the following advantages and positive effects:

[0017] The present invention is based on the gradient enthalpy The local cooling system of the mine takes into account the utilization efficiency and enthalpy of the cooling energy related to the refrigeration terminal in the mine. Efficiency is two important indicators, targeting the difficulty of increasing cooling capacity in existing technologies, low efficiency of cold energy utilization and enthalpy The problem of loss is proposed, and the gradient enthalpy is Theoretical, considering the enthalpy of the air cooler Different, using the principle of grade difference, establish gradient enthalpy Methods of utilizing cold energy to increase enthalpy Based on the above theory, modularization is used to calculate the enthalpy of each air. The differential adjustment can be carried out to improve the efficiency and increase the cooling capacity. Secondly, the cooling system can be flexibly adjusted, and the number of air coolers and units in operation can be flexibly adjusted according to actual needs, so that the actual temperature can be reduced to a lower level. The system is made more stable and reliable. Even if one of the air coolers cannot work properly, the other air coolers can also reduce the air to the required temperature. The present invention does not make major changes to the size and components of the equipment, but only changes its system structure to achieve the purpose, and the operation is practical.

[0018] By extension, this principle can be extended to be applied to refrigeration systems and central air-conditioning systems, etc., and can provide guidance for actual operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the working principle of a single refrigeration subsystem and a single air cooler;

[0020] Figure 2 It is a schematic diagram of the working principle of the system of the present invention. DETAILED DESCRIPTION

[0021] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0022] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative work are within the scope of protection of the present invention.

[0023] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0024] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0025] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly stipulated and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal connection of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] The working principle of a single refrigeration subsystem and a single air cooler is as follows Figure 1 As shown, it includes a refrigeration subsystem and an air cooler 9 arranged in a mine tunnel, an air supply device 10 arranged at the rear end of the air cooler 9 to send out the cooling gas in the air cooler 9, and a wind tube 8 connected to the front end of the air cooler 9 to guide the cooling gas in the air cooler 9 to the coal mining face 7; the refrigeration subsystem includes a condenser 3, an expansion valve 4, an evaporator 5 and a compressor 2 which are sequentially connected in series to form a closed loop; the inlet of the shell-side channel of the condenser 3 is connected to the cold source 1, and the outlet of the shell-side channel of the evaporator 5 is connected to the inlet of the shell-side channel of the air cooler 9. The outlet of the shell-side channel of the condenser 3 is connected to the cold source 1 to form a water circulation closed loop; the outlet of the shell-side channel of the air cooler 9 is connected to the inlet of the shell-side channel of the evaporator 5 to form a water circulation closed loop of the shell-side channel of the evaporator and the shell-side channel of the air cooler. The water circulation closed loop can promote the rational use of the cooling capacity of the entire system and achieve water conservation.

[0027] A first cooling water pump 11 is provided on the connection channel between the cold source 1 and the shell-side channel of the condenser 3. If the power is sufficient, the first cooling water pump 11 may not be provided. A second cooling water pump 6 is provided on the pipeline connecting the outlet of the shell-side channel of the evaporator 5 and the inlet of the shell-side channel of the air cooler 9. The second cooling water pump 6 can promote the flow of cold between the evaporator and the air cooler.

[0028] The theoretical basis of the above system is: T1>T2>T3, where T1 is the mine tunnel temperature at the rear end of the air supply device, which is similar to the temperature of the mine environment and is relatively high. T2 is the temperature of the tunnel fully mechanized working face after being cooled by the cooling system. T3 is the chilled water inlet temperature of a single air cooler when a single refrigeration subsystem and a single air cooler are working. T4 is the chilled water outlet temperature of a single air cooler when a single refrigeration subsystem and a single air cooler are working. After a single refrigeration subsystem and a single air cooler are working, the chilled water cools the air with a temperature of T1 to air with a temperature of T2 and sends it to the fully mechanized working face. The theoretical arguments are analyzed as follows:

[0029]

[0030] According to enthalpy expression:

[0031] e x，h =h-h0-t0×(s-s0)

[0032] Where: e x,h Express enthalpy , where x represents energy, h represents enthalpy, h0 represents the enthalpy of the environment, h represents the enthalpy of the study fluid, t0 represents the temperature of the environment, s represents the entropy of the study fluid, and s0 represents the entropy of the environment.

[0033] Find the enthalpy entering the system and the enthalpy of leaving the system , we can get the enthalpy efficiency:

[0034]

[0035] Thus, the enthalpy of each air cooler in series can be calculated. Efficiency, compared with a single air cooler, air coolers in series will increase enthalpy efficiency.

[0036] according to Loss formula:

[0037] I=T0×S g

[0038] Where I is loss, T0 is the ambient temperature, S g For entropy production.

[0039] It can be seen that in engineering, while not reducing the heat transfer effect, the heat transfer temperature difference is reduced and the series differential method is adopted to improve the overall operating efficiency of the unit.

[0040] Based on the above principle, the present invention proposes a method based on gradient enthalpy. Local cooling system of mines, such as Figure 2As shown, it includes several expandable refrigeration subsystems and several expandable air coolers 9 adapted to the refrigeration subsystems and arranged in the mine tunnel; several of the refrigeration subsystems respectively include a condenser 3, an expansion valve 4, an evaporator 5 and a compressor 6 which are sequentially connected in series to form a closed loop, several refrigeration subsystems are arranged in parallel and the condenser 3 of each refrigeration subsystem is connected to a cold source 1; several air coolers 9 are connected in series, and the shell channel inlets of several air coolers 9 are respectively connected to the evaporator 5 in the adapted refrigeration subsystem. The shell-side channel outlets of several air coolers 9 are respectively connected with the shell-side channel inlets of the evaporator 5 in the corresponding refrigeration subsystem to cool the airflow passing through the air cooler 9; there is a temperature difference between the airflow inlet of each air cooler 9 and the inlet of the shell-side channel, and the temperature difference between two adjacent air coolers 9 is equal or unequal; the air outlet end of the frontmost air cooler 9 is connected to the wind tube 8 and the air outlet of the wind tube 8 faces the coal mining working face 7, and the air inlet end of the rearmost air cooler 9 is connected to the air supply device 10.

[0041] Of the two adjacent air coolers 9, the shell-side passage inlet temperature of the air cooler 9 close to the coal mining face is lower than the shell-side passage inlet temperature of the air cooler 9 far from the coal mining face.

[0042] The cold source 1 is provided with an outlet pipe and an inlet channel; the inlet of the shell-side channel of the condenser 3 is connected to the outlet pipe of the cold source 1, and the outlet of the shell-side channel of the condenser 3 is connected to the inlet channel of the cold source 1 to form a water circulation closed loop. The water circulation closed loop can promote the rational use of the cooling capacity of the entire system and achieve water conservation.

[0043] The outlet pipe of the cold source 1 is provided with a first cooling water pump 11 to provide cooling to the condensers 3 of the refrigeration subsystem; the pipe connecting the outlet of the shell-side channel of the evaporator 5 and the inlet of the shell-side channel of the air cooler 9 is provided with a second cooling water pump 6. The second cooling water pump 6 can promote the flow of cooling between the evaporator 5 and the air cooler 9. The air supply device 10 is a fan; the condenser 3 is a water-cooled condenser, and the evaporator 5 is a water-cooled evaporator.

[0044] The working principle of the present invention is analyzed below:

[0045] and Figure 1 In contrast, when T1 remains unchanged, when T31 = T32 = T33 = T3n = T3 ( Figure 1 )hour,( Figure 2 ) in T2<( Figure 1 ) in T2, the system outlet will get lower temperature air. When T1 and T2 remain unchanged, T31 = T32 = T33 = T3n>T3, at this time In addition, when T1 and T2 remain unchanged, the temperature can be set to T31>T32>T33>T3n>T3, and the heat exchange temperature difference of each air cooler is reduced. The loss is reduced, and the actual project can be solved by N modules. In addition, the chilled water inlet temperature of each module can be flexibly adjusted to minimize the difference between the air temperature and the chilled water temperature processed by each air cooler. The local cooling system of the mine has significantly increased and expanded the cooling capacity, solving the problem of difficulty in increasing cooling capacity.

[0046] The basic working principle of the present invention is: the working medium completes the circulation in the refrigeration subsystem composed of the compressor, condenser, expansion valve and evaporator. The working medium in the condenser lowers the temperature by heat exchange with the cooling water pool, and the working medium in the evaporator exchanges heat with the chilled water, thereby absorbing the heat of the chilled water. The chilled water flows through the shell side of the air cooler to reduce the local temperature in the mine. After the chilled water exchanges heat with the air, it is circulated to the evaporator by the chilled water pump for heat exchange.

[0047] The present invention is based on the gradient enthalpy The local cooling system of the mine is to set up multiple air coolers in series on the same air duct to achieve gradient enthalpy and cold energy gradient utilization. Each air cooler and refrigeration subsystem are modularized, and the number of air coolers in operation can be flexibly adjusted according to actual needs, so that the actual temperature can be lowered to a lower level. The system is more stable and reliable. Even if one of the air coolers fails to work properly, the other air coolers can still reduce the air to the required temperature.

[0048] The present invention can achieve local cooling of the mine, provide protection for the health of workers and improve work efficiency. Multiple air coolers and multiple refrigeration subsystems are connected in series, which can improve the overall operating efficiency of the entire system and make the system more stable and reliable.

[0049] This embodiment does not impose any formal limitation on the shape, material, structure, etc. of the present invention. Any simple modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A local cooling system for mines based on an integrated gradient enthalpy module, characterized in that: The invention comprises several expandable refrigeration subsystems and several expandable air coolers which are matched with the refrigeration subsystems and arranged in the mine tunnel; the several refrigeration subsystems respectively comprise a condenser, an expansion valve, an evaporator and a compressor which are connected in series in sequence to form a closed loop, the several refrigeration subsystems are arranged in parallel and the condenser of each refrigeration subsystem is connected to a cold source; the several air coolers are connected in series, the shell channel inlets of the several air coolers are respectively connected to the shell channel outlets of the evaporator in the matched refrigeration subsystem, and the shell channel outlets of the several air coolers are respectively connected to the shell channel inlets of the evaporator in the matched refrigeration subsystem to cool down the air flow passing through the air cooler; a temperature difference is generated between the air flow inlet of each air cooler and the inlet of the shell channel, and the temperature difference between two adjacent air coolers is equal or unequal; the air outlet end of the frontmost air cooler is connected to a wind pipe and the air outlet of the wind pipe faces the coal mining working face, and the air inlet end of the rearmost air cooler is connected to an air supply device; the chilled water inlet temperature of each module is adjusted so that the difference between the air temperature processed by each air cooler and the chilled water temperature is minimized.

2. According to claim 1, the integrated mine local cooling system based on gradient enthalpy exergy module is characterized in that: Of the two adjacent air coolers, the shell side channel inlet temperature of the air cooler close to the coal mining working face is lower than the shell side channel inlet temperature of the air cooler far from the coal mining working face.

3. According to claim 2, the integrated mine local cooling system based on gradient enthalpy exergy module is characterized in that: The cold source is provided with an outlet pipe and an inlet channel; the inlet of the shell-side channel of the condenser is connected to the outlet pipe of the cold source, and the outlet of the shell-side channel of the condenser is connected to the inlet channel of the cold source to form a water circulation closed loop.

4. According to claim 3, the integrated mine local cooling system based on gradient enthalpy exergy module is characterized in that: A first cooling water pump is arranged on the outlet pipe of the cold source to provide cooling to the condensers of several refrigeration subsystems; a second cooling water pump is arranged on the pipe connecting the outlet of the evaporator shell channel and the inlet of the air cooler shell channel.

5. According to claim 4, the integrated mine local cooling system based on gradient enthalpy exergy module is characterized in that: The air supply device is a fan; the condenser is a water-cooled condenser, and the evaporator is a water-cooled evaporator.

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