阅读说明：本技术 一种高地温地质隧道降温系统及应用方法 (High-ground-temperature geological tunnel cooling system and application method ) 是由 李世海 高之然 张一鸣 于 2019-10-17 设计创作，主要内容包括：本发明公开一种高地温地质隧道降温系统及应用方法,通过冷水循环降温和蒸发相变吸收能量两种作用方式,实现高地温地质隧道内部环境降温,降温系统包括导水导气装置、储水沸腾装置和气体排热装置；系统通过导水导气装置将冷水通入导水管中,冷水在流动过程中吸收热量,并流入沸腾箱；气体排热装置中的抽气泵不断抽取沸腾箱内空气,以降低箱内气压；水储存于储水沸腾装置后,伴随气压不断降低达到低压条件下的水沸点,水发生相变,经沸腾过程吸收大量热量,并以水蒸气形式被导气装置排出。本发明结合冷水循环降温和相变吸收能量,以达到对隧道内部快速降温、集中排热的目的,有效改善高地温地质条件下的高温恶劣环境,提高人员舒适度与工作效率。(the invention discloses a high-ground-temperature geological tunnel cooling system and an application method thereof, wherein the internal environment cooling of a high-ground-temperature geological tunnel is realized through two action modes of cold water circulation cooling and evaporation phase change energy absorption; the system leads cold water into the water guide pipe through the water and gas guide device, and the cold water absorbs heat in the flowing process and flows into the boiling tank; an air pump in the gas heat-exhausting device continuously pumps air in the boiling box so as to reduce the air pressure in the box; after the water is stored in the water storage boiling device, the water reaches the water boiling point under the low-pressure condition along with the continuous reduction of the air pressure, the water undergoes phase change, absorbs a large amount of heat in the boiling process, and is discharged by the air guide device in the form of water vapor. The invention combines cold water circulation cooling and phase change absorption energy to achieve the purposes of quickly cooling and intensively discharging heat in the tunnel, effectively improves the high-temperature severe environment under the high ground temperature geological condition, and improves the comfort level of personnel and the working efficiency.)

1. the utility model provides a high ground temperature geological tunnel cooling system which characterized in that: the tunnel water-gas-storage boiling device comprises a water-storage boiling device, a gas heat extraction device and a plurality of water-guiding and gas-guiding devices, wherein the inlets and the outlets of the water-guiding and gas-guiding devices are sequentially connected in series, the gas outlet of the water-guiding and gas-guiding device far away from a working surface is connected with the inlet of the gas heat extraction device, the water outlet and the gas inlet of the water-guiding and gas-guiding device close to the working surface are connected with the water inlet and the gas outlet of the water-storage boiling device, the water-storage boiling device is arranged close to a rock wall;

The water and gas guiding device comprises a water filling port, a water guiding pipe, a gas guiding pipe and a first heat insulation plate; the water guide pipe is fixed on the first heat insulation plate, a water inlet of the water guide pipe is connected with a water injection port, a gas guide pipe is fixed on the first heat insulation plate above the water guide pipe through a gas guide pipe fixing clamp, and the gas guide pipe is arranged along the length direction of the tunnel; the first heat insulation plate is fixed on the rock wall of the tunnel;

The water storage boiling device comprises a boiling box and a second heat insulation plate; the boiling box is fixed on the tunnel rock wall near the working surface through a second heat insulation plate, the lower part of the boiling box is provided with a water inlet of the boiling box, the water inlet of the boiling box is connected with the water outlet of the water guide pipe of the adjacent water and gas guide device through a related pipeline and a water guide pipe connector, the upper part of the boiling box is provided with a gas outlet of the boiling box, and the gas outlet of the boiling box is connected with the gas inlet of the gas guide pipe of the adjacent water and gas guide device through a related pipeline and a gas;

The gas heat extraction device comprises an air pump, a heat extraction pipe and a heat dissipation box, wherein the air inlet end of the air pump is connected with the air outlet of the air guide pipe of the adjacent water guide and air guide device, the air outlet end of the air pump is connected with the interface of the heat extraction pipe through the heat extraction pipe, and the interface of the heat extraction pipe is connected with the heat dissipation box; the heat dissipation box is placed on the ground of the tunnel, and the air suction pump is fixed on the tunnel rock wall at the tail end of the air guide pipe.

2. the tunnel cooling system of claim 1, wherein: the diameter of the water guide pipe in the water and gas guide device is smaller than that of the gas guide pipe.

3. The tunnel cooling system of claim 1, wherein: the first heat insulation plates in the water and gas guiding devices are set to be of fixed size, the first heat insulation plates of a plurality of groups of same water and gas guiding devices are spliced together, and corresponding pipelines are connected by using joints.

4. the tunnel cooling system of claim 1, wherein: and a pressure gauge is arranged on the boiling box.

5. The tunnel cooling system of claim 1, wherein: ice blocks are placed in the heat dissipation box.

6. The tunnel cooling system of claim 1, wherein: the system is arranged in the tunnel in the range close to the working surface by 10 m.

7. a method for applying the tunnel cooling system of claim 1, the method comprising the steps of;

1) calculating the heat quantity to be absorbed by water vapor with the water evaporation of 1m ³ under any pressure and temperature state, summarizing the corresponding relation among the temperature, the pressure and the heat quantity to be absorbed by the water vapor with the water evaporation of 1m ³, and listing;

2) Performing function fitting according to the temperature data in the list and the heat data to be absorbed by the water vapor with the water evaporation of 1m ³ to obtain a relation between the heat to be absorbed by the water vapor of 1m ³ and the temperature data, integrating the relation between the initial ambient temperature t1 and the target ambient temperature t2 to obtain an equation (3),

Wherein K is the heat absorbed when the ambient temperature of the water vapor evaporating 1m ³ is reduced from t ₁ to t ₂;

3) Calculating the evaporation of 1m ³ water vapor to ensure that the local air volume in the tunnel can be influenced when the ambient temperature is reduced from t ₁ to t ₂, and setting the corresponding rated power of the air pump by combining the total volume of the tunnel construction space, the K value calculated in the step 2) and the time required for reducing the initial ambient temperature t ₁ to the target temperature t ₂;

simultaneously searching the list in the step 1) to find out the target pressure corresponding to the target environment temperature t, and further determining the target air pressure required to be reached in the water storage boiling device;

Injecting cold water from a water injection port of a water and gas guiding device far away from a working surface, so that the cold water circulates in the water guiding pipe, absorbs heat in the flowing process of the cold water and finally flows to a boiling tank in the water storage boiling device; air in the boiling box is pumped by using an air pump in the gas heat removal device, so that the air pressure in the boiling box is reduced, and the boiling point of water in the boiling box is reduced; when water flows from the water guide pipe to the boiling box, the liquid level evaporation area is rapidly increased, and the air pressure is reduced, so that the water starts to boil and absorbs a large amount of heat.

The technical field is as follows:

The invention relates to the technical field of cooling of high-ground-temperature geological tunnels, in particular to a cooling system of a high-ground-temperature geological tunnel and an application method thereof, which are used for cooling and radiating the interior of the high-ground-temperature tunnel.

Background art:

Along with the rapid development of national economy, the construction of infrastructure of China gradually deepens into areas with complex geological conditions. The high ground temperature and the abnormal region of the ground heat are complex geological environments which are frequently crossed by the tunnel, are particularly concentrated in the Tibet, Yunnan, Xinjiang and other regions of China, and the tunnel construction process is very easily affected by the high ground heat due to frequent underground heat activities, so that the tunnel construction and long-term operation are seriously threatened. For example, in a Gilles curve tunnel of the Tibet Ramari railway, the maximum burial depth is 102 meters, and the highest geothermal temperature reaches 65.4 ℃; the maximum burial depth of a Gaili tribute mountain tunnel of a big Rui railway in Yunnan is 1155 meters, and the highest temperature of geothermal energy can reach 100 ℃; the maximum burial depth of the diversion tunnel of the Xinjiang Blueman-Gorgell power station is 300 meters, and the maximum geothermal temperature can reach 82 ℃. However, in the areas where the national civilian needs and the national strategic development control are in place, the research on the cooling technology of the high-ground-temperature geological tunnel is urgently needed.

in the current research, the working environment of the underground tunnel is considered to be relatively closed, and the high-temperature environment will have serious influence on the construction, so that cooling treatment measures need to be taken in the tunnel. At present, some measures such as arranging a heat insulation layer, cooling by water spraying evaporation, cooling by cold water circulation and the like are also taken for solving the problem of high ground temperature of the tunnel, but the method has little effect and cannot effectively solve the problem that the construction is influenced by the high ground temperature of the tunnel.

The invention content is as follows:

The invention aims to provide a high-ground-temperature geological tunnel cooling system and an application method thereof, which are used for solving the problems in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

The utility model provides a high ground temperature geological tunnel cooling system which characterized in that: the tunnel water-gas-storage boiling device comprises a water-storage boiling device, a gas heat extraction device and a plurality of water-guiding and gas-guiding devices, wherein the inlets and the outlets of the water-guiding and gas-guiding devices are sequentially connected in series, the gas outlet of the water-guiding and gas-guiding device far away from a working surface is connected with the inlet of the gas heat extraction device, the water outlet and the gas inlet of the water-guiding and gas-guiding device close to the working surface are connected with the water inlet and the gas outlet of the water-storage boiling device, the water-storage boiling device is arranged close to a rock wall;

The water and gas guiding device comprises a water filling port, a water guiding pipe, a gas guiding pipe and a first heat insulation plate; the water guide pipe is fixed on the first heat insulation plate, a water inlet of the water guide pipe is connected with a water injection port, a gas guide pipe is fixed on the first heat insulation plate above the water guide pipe through a gas guide pipe fixing clamp, and the gas guide pipe is arranged along the length direction of the tunnel; the first heat insulation plate is fixed on the rock wall of the tunnel;

The water storage boiling device comprises a boiling box and a second heat insulation plate; the boiling box is fixed on the tunnel rock wall near the working surface through a second heat insulation plate, the lower part of the boiling box is provided with a water inlet of the boiling box, the water inlet of the boiling box is connected with the water outlet of the water guide pipe of the adjacent water and gas guide device through a related pipeline and a water guide pipe connector, the upper part of the boiling box is provided with a gas outlet of the boiling box, and the gas outlet of the boiling box is connected with the gas inlet of the gas guide pipe of the adjacent water and gas guide device through a related pipeline and a gas;

The gas heat extraction device comprises an air pump, a heat extraction pipe and a heat dissipation box, wherein the air inlet end of the air pump is connected with the air outlet of the air guide pipe of the adjacent water guide and air guide device, the air outlet end of the air pump is connected with the interface of the heat extraction pipe through the heat extraction pipe, and the interface of the heat extraction pipe is connected with the heat dissipation box; the heat dissipation box is placed on the ground of the tunnel, and the air suction pump is fixed on the tunnel rock wall at the tail end of the air guide pipe.

The diameter of the water guide pipe in the water and gas guide device is smaller than that of the gas guide pipe.

the first heat insulation plates in the water and gas guiding devices are set to be of fixed size, the first heat insulation plates of a plurality of groups of same water and gas guiding devices are spliced together, and corresponding pipelines are connected by using joints.

and a pressure gauge is arranged on the boiling box.

ice blocks are placed in the heat dissipation box.

the system is arranged in the tunnel in the range close to the working surface by 10 m.

The application method of the tunnel cooling system comprises the following steps;

1) Calculating the heat quantity to be absorbed by water vapor with the water evaporation of 1m3 under any pressure and temperature state, summarizing the corresponding relation among the temperature, the pressure and the heat quantity to be absorbed by the water vapor with the water evaporation of 1m3, and listing;

2) Performing function fitting according to the temperature data in the list and the heat data to be absorbed by the water vapor with the water evaporation of 1m3 to obtain a relation between the heat to be absorbed by the water vapor of 1m3 and the temperature data, integrating the relation between the initial ambient temperature t1 and the target ambient temperature t2 to obtain an equation (3),

Wherein K is the heat absorbed when the ambient temperature of the water vapor evaporating 1m3 is reduced from t ₁ to t ₂;

3) calculating the evaporation of 1m3 water vapor to ensure that the local air volume in the tunnel can be influenced when the ambient temperature is reduced from t ₁ to t ₂, and setting the corresponding rated power of the air pump by combining the total volume of the tunnel construction space, the K value calculated in the step 2) and the time required for reducing the initial ambient temperature t ₁ to the target temperature t ₂;

simultaneously searching the list in the step 1) to find out the target pressure corresponding to the target environment temperature t, and further determining the target air pressure required to be reached in the water storage boiling device;

Injecting cold water from a water injection port of a water and gas guiding device far away from a working surface, so that the cold water circulates in the water guiding pipe, absorbs heat in the flowing process of the cold water and finally flows to a boiling tank in the water storage boiling device; air in the boiling box is pumped by using an air pump in the gas heat removal device, so that the air pressure in the boiling box is reduced, and the boiling point of water in the boiling box is reduced; when water flows from the water guide pipe to the boiling box, the liquid level evaporation area is rapidly increased, and the air pressure is reduced, so that the water starts to boil and absorbs a large amount of heat.

compared with the prior art, the invention has the advantages that:

1. Compared with the traditional cold water circulation cooling technology, the cooling effect is poor, the water after circulation needs to be cooled repeatedly, and energy is wasted, the method firstly utilizes cold water to cool the internal environment of the tunnel, takes away part of heat, and then changes the internal pressure of the boiling box, so that the water boils in the evaporation box to absorb heat, and most of the heat can be taken away. On the basis of cooling cold water, the invention absorbs a large amount of heat by utilizing the phase change of water, and has simple operation and obvious cooling effect.

2. The water and gas guiding device is characterized in that an assembled duct piece formed by connecting stainless steel pipes in a threaded manner is used as a water guide pipe, the assembly and disassembly are simple and convenient during maintenance and curing of the stainless steel pipes, each heat insulation plate, the water guide pipe and the gas guide pipe on the heat insulation plate form a group of water and gas guiding devices, the assembly between adjacent heat insulation plates and the assembly between adjacent water guide pipes is simple and rapid, and the water and gas guiding devices can be disassembled for recycling along with the propulsion of tunnel construction.

3. The gas heat extraction device provided by the invention concentrates the extracted hot air and the steam with heat for cooling treatment, ensures that the heat does not influence the cooling treatment in the tunnel, and is simple and convenient to operate and low in cost.

4. the tunnel cooling system is arranged close to the working face, the tunnel cooling system can be installed along with the propulsion of the tunnel face, and a sectional cooling mode is adopted (the first section is that cold water can absorb heat and cool in a section range of the tunnel after the water is injected into a plurality of connected water guide devices, and the second section is that a large amount of heat is absorbed intensively due to the fact that the phase change of water is generated by changing the internal pressure after the water is injected into a boiling box close to the working face (the tunnel face), so that the temperature of the construction environment is quickly reduced, and the tunnel cooling system can be quickly and effectively cooled in each construction stage.

In conclusion, the system realizes the cooling of the internal environment of the high-ground-temperature geological tunnel through two action modes of cold water circulation cooling and phase change energy absorption, the system leads cold water into the water guide pipe through the water guide and gas guide device, and the cold water absorbs heat in the flowing process; the air pump in the gas heat-discharging device continuously pumps air in the boiling box so as to reduce the air pressure in the boiling box; after water is stored in the water storage boiling device, the water reaches the water boiling point under the condition of low pressure along with the continuous reduction of air pressure, the phase of the water is changed, and a large amount of heat is absorbed through the boiling process. The invention combines cold water circulation cooling and phase change absorption energy to achieve the purposes of quickly cooling the interior of the tunnel and intensively discharging heat, and effectively solves the problem of high ground temperature.

description of the drawings:

FIG. 1 is a schematic structural diagram of a high-ground-temperature geological tunnel cooling system.

FIG. 2 is a schematic connection diagram of a high-low temperature geological tunnel cooling system device.

FIG. 3 is a schematic diagram of the installation position of the tunnel cross section of the cooling system of the high-ground-temperature geological tunnel.

FIG. 4 is a tunnel longitudinal section installation mode schematic diagram (a-a section view) of a high-ground-temperature geological tunnel cooling system.

Figure 5 is a graph of the temperature fitted to the amount of heat absorbed to evaporate 1m3 of water vapor.

In the figure: 1-water injection port; 2-a water conduit; 3-a water inlet of the boiling tank; 4-aqueduct connector; 5-a boiling box; 6-an air outlet of the boiling tank; 7-an air duct; 8-gas-guide tube connector; 9-an air pump; 10-heat exhausting pipe; 11-heat removal pipe interface; 12-a heat dissipation box; 13-aqueduct fixing clip, 15-airway fixing clip; 14-a first insulation board; 16-a second insulation board.

The specific implementation mode is as follows:

The present invention will be described in further detail with reference to the drawings in the following embodiments, but the present invention is not limited to the following embodiments.

Referring to fig. 1, the present invention provides a technical solution: a high-ground-temperature geological tunnel cooling system comprises a water storage boiling device, a gas heat extraction device and a plurality of water and gas guide devices, wherein the inlets and the outlets of the plurality of water and gas guide devices are sequentially connected in series, the gas outlet of the water and gas guide device far away from a working surface is connected with the inlet of the gas heat extraction device, the water outlet and the gas inlet of the water and gas guide device close to the working surface are connected with the water inlet and the gas outlet of the water storage boiling device, the water storage boiling device is installed close to a rock wall near the working surface, and the plurality of water and gas guide devices are sequentially arranged along the length direction of;

The water and gas guiding device comprises a water filling port 1, a water guiding pipe 2, a gas guiding pipe 7 and a first heat insulating plate 14; the water guide pipe 2 is fixed on the first heat insulation plate 14 in a snake shape, the water inlet of the water guide pipe 2 is connected with the water injection port 1, the first heat insulation plate 14 above the water guide pipe 2 is fixed with the air guide pipe 7 through the air guide pipe fixing clamp 15, and the air guide pipe 7 is arranged along the length direction of the tunnel; the first heat insulation plates 14 are fixed on the rock wall of the tunnel;

the stored water boiling device comprises a boiling box 5 and a second heat insulation plate 16; the boiling box 5 is fixed on the tunnel rock wall near the working surface through a second heat insulation plate 16, the lower part of the boiling box 5 is provided with a boiling box water inlet 3, the boiling box water inlet 3 is connected with the water outlet of the water guide pipe 2 of the adjacent water and gas guide device through a related pipeline and a water guide pipe connector 4, the upper part of the boiling box 5 is provided with a boiling box gas outlet 6, and the boiling box gas outlet 6 is connected with the gas inlet of the gas guide pipe 7 of the adjacent water and gas guide device through a related pipeline and a gas guide pipe connector 8;

The gas heat removal device comprises an air pump 9, a heat discharge pipe 10 and a heat dissipation box 12, wherein the air inlet end of the air pump 9 is connected with the air outlet of the air guide pipe 7 of the adjacent water guide and air guide device, the air outlet end of the air pump 9 is connected with a heat discharge pipe interface 11 through the heat discharge pipe 10, and the heat discharge pipe interface 11 is connected with the heat dissipation box 12; the heat dissipation box 12 is fixed on the ground far away from the tunnel working surface, and the air pump 9 is fixed on the tunnel rock wall at the tail end of the air guide pipe 2.

A pressure gauge is arranged on a boiling box 5 in the water storage boiling device, and the pressure inside the boiling box can be observed at any time.

The aqueduct is connected with the aqueduct by an aqueduct connector, and the air duct is connected with the air duct by an air duct connector.

The diameter of the water guide pipe in the water and gas guide device is smaller than that of the gas guide pipe.

The first heat insulation plates in the water and gas guiding devices are set to be of fixed size, the first heat insulation plates of a plurality of groups of same water and gas guiding devices are spliced together, and corresponding pipelines are connected by using joints.

When the tunnel is constructed, the tunnel is gradually pushed forward by a construction section, and the construction process of the whole tunnel is completed. The cooling system for the high-ground-temperature geological tunnel is generally arranged in a section of the tunnel, which is close to a working surface, wherein a group of water storage boiling devices is arranged at the section close to the working surface, a plurality of groups of water and gas guiding devices are continuously connected along the direction far away from the working surface, and finally a group of gas heat removal devices are connected. The number of the general water and air guide devices is set to be 5-6, and after the construction of the construction section is completed, the whole forward moving cooling system is installed on the next working face to carry out the construction of the next construction section.

The invention comprises two cooling modes: firstly, the part of injected cold water which flows through the water guide pipe for cooling relates to the problem of heat absorption and cooling of the traditional cold water conduction; secondly, the low-pressure boiling, heat absorption and temperature reduction of water involve changing the ambient air pressure to reduce the boiling point of water, so that the water is quickly boiled, and a large amount of heat is absorbed by utilizing the phase change process of the water. The two heat absorption processes are combined, so that the rapid cooling in the high-ground-temperature tunnel can be ensured, and the temperature is kept constant when the temperature is reduced to a target temperature value.

The working principle of the cooling system is as follows: cold water is injected from a water injection port 1 of a water and gas guiding device far away from a working surface, and the cold water circulates in a water guiding pipe 2 to absorb heat in the flowing process and flow to a boiling tank 5 in a water storage boiling device; air in the boiling box 5 is pumped by using an air pump 9 in the gas heat removal device, so that the air pressure in the boiling box 5 is reduced, and the boiling point of water in the boiling box 5 is reduced; when water flows from the water guide pipe 2 to the boiling box 5, the liquid surface evaporation area is rapidly increased, and in addition, the air pressure is reduced, so that the water starts to boil and absorbs a large amount of heat; ice cubes are placed in the heat dissipation tank 12 for intensive treatment of the hot air and water vapour extracted by the suction pump 9 in the air duct 7.

wherein, the energy conversion mechanism is as follows:

According to the ideal gas state equation:

PV＝nRT (1)

Wherein P represents the state parameter pressure, V represents the gas volume, n represents the amount of the substance, T represents the absolute temperature, R is the gas constant which is approximately equal to 8.314 Pa.m ³/mol.K. when the vaporization latent heat table of the combined water calculates the boiling points of the corresponding different water under different air pressures, the air pressure and the molar mass of 1m3 water vapor under the corresponding temperature, thereby calculating the mass of the water vapor, and finally obtaining the heat quantity to be absorbed by the water vapor which is 1m3 in the state, which is summarized as table 1.

TABLE 1 relationship of the heat absorbed by the water vapor evaporated to 1m3 vapor at different temperatures and pressures in the boiler

Performing function fitting according to the corresponding relation between the temperature t of the second row of data and the heat to be absorbed by the water vapor of which the water evaporation is 1m3 in the last row of data in the table 1, wherein a fitting curve is shown in fig. 4, wherein the abscissa is the temperature t and the unit is; the ordinate is the heat k in kJ. The fitting formula is as follows:

k＝0.2179t²-10.475t+162.16 (2)

Thus, the boiling absorption energy formula when the water reaches the ambient temperature t2 after the water boils to absorb heat from the initial ambient temperature t1 is obtained as formula (3):

wherein t ₁ is the initial ambient temperature, t ₂ is the ambient temperature after water boils to absorb heat, and K is the amount of heat absorbed when the ambient temperature decreases from t ₁ to t ₂, and the unit is kJ.

in the ideal case, according to the formula for specific heat capacity:

q＝Cm_{air (a)}Δt＝CρvΔt

Δt＝t₁-t₂

wherein q is heat, the unit is J, C is specific heat capacity, the unit is J/kg, rho is density of air, the unit is kg/m ³, and v is volume of air.

q is K, so that when evaporating 1m ³ water vapor so that the ambient temperature drops from t ₁ to t ₂, the volume of air that can be affected is:

According to the air volume V of the actually required cooling environment_{General assembly}It can be calculated that:

Further, the total heat absorption required to reduce the temperature of the air within the specified ambient volume from t ₁ to t ₂ can be calculated as:

Q＝a·K (6)

from this, the volume is V_{General assembly}Temperature of air of m3 from t₁down to t₂when evaporation a m is required³Water vapor, total heat absorption of water vapor QkJ.

the application process of cooling by using the cooling system is as follows:

Recording the current initial ambient temperature t₁And setting a target temperature as the ambient temperature t after the water is boiled to absorb heat₂The energy absorbed by boiling in this time period is calculated according to equation (6), i.e. the volume is V_{General assembly}Temperature of air of m3 from t₁Down to t₂Total heat absorption required is QkJ;

simultaneously looking up the boiling temperature of the second column in the table 1, finding out the target pressure corresponding to the target temperature t ₂, and further determining the pressure required to be reached inside the water storage boiling device;

adjusting the output power of the air pump according to the pressure value inside the boiling box displayed by the pressure gauge, increasing the power when the pressure does not reach the pressure corresponding to the target temperature, and stabilizing the output power of the air pump to keep the current pressure value inside the boiling box when the pressure reaches the pressure corresponding to the target temperature, so that the ambient temperature is stabilized at the target temperature value;

Finally, the corresponding power rating of the pump is set based on the total heat absorption Q and the time required to drop from the initial ambient temperature t ₁ to the target temperature t ₂.