KR101200896B1 - Measuring device of geothermal conductivity - Google Patents

Abstract

The present invention includes a first pipe for extracting groundwater from a well, a second pipe for discharging groundwater to a well, a first flow passage having one end and the other end connected to the first and second pipes, and the first flow passage. A heating unit for heating and discharging the groundwater introduced into the outlet, a temperature sensor installed at the inlet / outlet side of the first channel, for measuring a temperature at the inlet / outlet side of the first channel, and storing data measured by the temperature sensor; And a data processor configured to process the ground heat conductivity, wherein the heating unit is installed between the boiler for supplying steam to a second channel installed at one side of the first channel, and the first and second channels. A ground heat conductivity measuring apparatus comprising a heat exchanger for exchanging groundwater in one euro and steam in the second flow path, wherein a large amount of heat can be input. Value can be downsized and securing of reliability can be provided a structure capable of measuring apparatus.

Description

Underground thermal conductivity measuring device {MEASURING DEVICE OF GEOTHERMAL CONDUCTIVITY}

The present invention relates to an underground thermal conductivity measuring apparatus for measuring the thermal conductivity of the ground using groundwater.

Recently, in order to increase domestic energy independence, the promotion of renewable energy facilities has been promoted. Geothermal energy is considered to be the most economical energy source.

As a facility using such geothermal energy, there is a ground-source heat pump system. While commonly used air heat source heat pumps use energy from the outside air (summer: 30 to 38 ° C, winter: -5 to -15 ° C) that varies greatly with the environment, geothermal heat pump systems always maintain a constant temperature (15 Maximize the overall efficiency of the heat pump by using the characteristics of the ground to maintain the temperature.

The geothermal heat pump system has a heat pump unit that is responsible for temperature control of a controlled object (for example, a building), and a geothermal heat exchanger serving as a heat source or heat sink of the heat pump unit.

In order to use underground heat, a method of embedding underground heat exchanger by drilling the ground around the building is generally used. Determination of depth and number of perforations of underground heat exchanger is to reflect underground thermal conductivity in design. Underground thermal conductivity is the most important variable in the design of underground heat exchangers. If the ground heat exchanger is designed to measure the ground heat conductivity value to be larger than the actual value, the performance will be insufficient. If the ground heat exchanger is designed to be measured to a value smaller than the actual value, the construction cost is unnecessarily high. Therefore, underground thermal conductivity measuring apparatus for measuring underground thermal conductivity has been proposed in various forms.

Recently, a research for applying a heat exchanger using energy of groundwater has been conducted. In order to use groundwater, the length and depth of input of the ground heat exchanger are increased, and the amount of heat to be input during the thermal conductivity test is increased. Therefore, an underground thermal conductivity measuring device suitable for such a test is required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is intended to provide an underground thermal conductivity measuring apparatus having a small size and capable of inputting a large amount of heat.

In addition, the present invention is to provide a structure of the underground thermal conductivity measuring apparatus that can be injected while a large amount of heat can be secured.

In order to achieve the above object, the present invention provides a first pipe for extracting groundwater from a well, a second pipe for discharging groundwater to the well, and a first end connected to the first and second pipes, respectively. A heating unit for heating and discharging a flow path, groundwater introduced into the first flow passage, a temperature sensor installed at an inlet and outlet side of the first passage, and a temperature sensor for measuring an inlet and outlet side temperature of the first passage, and the temperature sensor And a data processor configured to store and process the data measured in FIG. 3, wherein the heater supplies steam to a second channel installed at one side of the first channel, and the first and second channels. An underground thermal conductivity measuring apparatus is installed between the first flow path and a heat exchanger for heat-exchanging the steam in the second flow path.

The boiler may be in the form of an electric steam boiler, and an electric valve may be installed in the second passage to adjust a flow rate of steam introduced into the heat exchanger. Here, the electric valve may be connected to a control unit for applying a control signal for adjusting the opening degree to the electric valve to adjust the amount of heat input to the heat exchanger.

The first flow passage may include a gas flow passage and a bypass flow passage branched from the fuel flow passage, and the fuel passage and the bypass flow passage may be provided with valves for selectively opening the fuel flow passage and the bypass flow passage. In this case, a pump for self-circulation of the fluid may be installed in the main passage or the bypass passage.

The data processor may be configured to calculate a thermal conductivity by calculating a temperature change per hour of the well ground water based on the data of the temperature sensor and the input heat amount of the boiler.

According to the present invention having the above configuration, it is possible to input a large amount of heat through the structure of applying heat to the first flow path through the boiler and the heat exchanger while miniaturizing the size of the measuring device compared to the input calorific value.

In addition, the present invention has the advantage that it is possible to insert a large amount of heat while ensuring stability, there is an advantage that can be precise calorie control using the electric valve.

In addition, the present invention may optionally use the measuring device open or closed through additional configuration of the bypass flow path and the pump.

1 is a conceptual diagram of an underground thermal conductivity measuring apparatus according to an embodiment of the present invention.
2 is a graph showing the temperature measured by the temperature sensor as a change in temperature per hour.
3 is a graph showing the conversion of the natural log in FIG.

Hereinafter, the underground thermal conductivity measuring apparatus according to the present invention will be described in more detail with reference to the accompanying drawings.

1 is a conceptual diagram of an underground thermal conductivity measurement apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the underground thermal conductivity measuring apparatus includes a first pipe 110, a second pipe 120, a first flow passage 130, a heating unit 140, a temperature sensor 161 and 162, and a data processing unit 170. ).

The first and second pipes 110 and 120 are for extracting and discharging groundwater from the well 10 drilled at the site, respectively, and are inserted into the drilled borehole from the ground to the position of the groundwater. The first pipe 110 is installed with an underwater pump 115, through which the groundwater of the well 10 can be pulled up. The first and second pipes 110 and 120 may be referred to as 'underground heat exchangers' in terms of a device for heat exchange with the ground.

One end and the other end of the first channel 130 are connected to the first and second pipes 110 and 120, respectively. The groundwater introduced into the first passage 130 through the first pipe 110 is discharged to the second pipe 120 after moving the first passage 130. The first and second pipes 110 and 120 may be connected to the first channel 130 by the connectors 111 and 121.

The first and second pipes 110 and 120 are not connected to each other, so that the first passage 130 is in an open state. In this respect, the measuring device of the present invention may be referred to as an 'open type' measuring device. . On the contrary, when the first and second pipes 110 and 120 are connected to each other so that the first passage 130 has a sealed structure, this type may be referred to as a 'closed type' measuring device.

The flow meter 150 may be installed on the first flow path 130, and the display unit 151 may be installed on the flow meter 150 to display the flow rate of the first flow path 130 during operation of the measuring device.

In addition, a strainer 135 may be installed at the inlet side of the first passage 130 to filter foreign matter, and a valve 136 for opening and closing the first passage 130 may be installed at the outlet side of the first passage 130. Can be installed.

The heating unit 140 functions to heat the groundwater introduced into the first flow passage 130.

The temperature sensors 161 and 162 are installed at the inlet side and the outlet side of the first passage 130, respectively, and measure the temperature at the inlet and outlet side of the first passage 130. The inlet side temperature of the first channel 130 will be the outlet temperature of the underground heat exchanger (110, 120), the outlet side temperature of the first channel 130 will be the inlet temperature of the underground heat exchanger (110, 120).

The data processor 170 stores and processes the data measured by the temperature sensors 161 and 162 to calculate the underground thermal conductivity. The data processor 170 is connected to the flow meter 150 and the temperature sensors 161 and 162 and configured to store and process data transmitted from them.

According to the present invention, the heating unit 140 has a configuration including the boiler 141 and the heat exchanger 142 so as to apply a large amount of heat to the ground water of the first passage 130.

The boiler 141 functions to supply steam to the second passage 145 installed on one side of the first passage 130. The boiler 141 has the form of an electric steam boiler, which is connected to the controller 180 and is controlled by the controller 180. The controller 180 controls the boiler 141 so that the boiler 141 can supply a predetermined amount of heat to the second flow passage 145. Here, the heat supply of the boiler 141 can be set by the user's selection.

The heat exchanger 142 is installed between the first passage 130 and the second passage 145, and heat-exchanges the groundwater of the first passage 130 and the steam of the second passage 145. As the groundwater of the first flow passage 130 passes through the heat exchanger 142, it is heated by the amount of heat provided by the steam of the second flow passage 145.

An electric valve 143 may be installed on the second flow path 145 to adjust the flow rate of steam introduced into the heat exchanger 142. The electric valve 143 is installed at the inlet side of the heat exchanger 142 and is electrically connected to the controller 180. The controller 180 applies a control signal for adjusting the opening degree of the electric valve 143 to adjust the amount of heat input to the heat exchanger.

As described above, the method of applying heat to the first flow path 130 through the boiler 141 and the heat exchanger 142 enables a large amount of heat to be input, but can reduce the size of the measuring device to the amount of heat input. In addition, there is an advantage that can be injected while a large amount of heat can be secured, there is an advantage that can be precise calorie control using the electric valve (143).

Meanwhile, the first passage 130 may include a gas passage 131 and a bypass passage 132 branched from and joined to the fuel passage 131.

In this case, the oil passage 131 and the bypass passage 132 are provided with first and second valves 133 and 134 for selectively opening them. When the first valve 133 is opened and the second valve 134 is closed, only the oil passage 131 is opened. When the first valve 133 is closed and the second valve 134 is opened, only the bypass passage 132 is opened. .

The main oil passage 131 or the bypass passage 132 may be provided with a pump 190 for circulating the fluid of the first passage 130 itself. This embodiment illustrates that the pump 190 is installed in the oil passage 131, the pump 190 is also connected to the control unit 180 is controlled by it.

According to this configuration, it is possible to selectively use the underground thermal conductivity measuring device open or closed.

When closing the gas passage 131 and opening the bypass passage 132, the groundwater of the first passage 130 is bypassed to the bypass passage 132 to be discharged to the outside of the first passage 130, in which case the measurement The device can be used as an open measuring device.

When opening the gas passage 131 and closing the bypass passage 132, the fluid of the first passage 130 is discharged to the outside of the first passage 130 through the fuel passage 131, in this case the measuring device It can be used as a closed measuring device. In this case, a structure in which the first and second pipes 110 and 120 are connected to each other is used as the ground heat exchanger, and the pump 190 functions to circulate the fluid of the first flow path 130 by itself.

The controller 180 includes an operation switch for applying power to various devices, for example, the boiler 141, the electric valve 143, the pump 190, and the like, and a control panel for controlling the operation of each component.

Hereinafter, a method of measuring underground thermal conductivity using the underground thermal conductivity measuring apparatus of the present invention will be described.

The method of measuring thermal conductivity of the present invention has a method of elevating the groundwater of the well by using the submersible pump 115, and then applying the amount of heat to the groundwater by using the heating unit 140 to discharge the groundwater to the well. The warmed ground water diffuses heat from the well to the rock, and the cooled ground water is circulated by being pulled back to the measuring device by the submersible pump 115.

The temperature sensors 161 and 162 periodically measure the temperature of the groundwater that moves the first flow passage 130 for a predetermined time and apply it to the data processor 170.

2 is a graph showing the temperature measured by the temperature sensor as a change in temperature per hour, and FIG. 3 is a graph showing the natural log converted to FIG. 2.

Underground thermal conductivity is obtained from temperature changes with time when heat is injected or extracted. In the present invention, the thermal conductivity calculation is based on a line source model that analyzes the ground heat conductivity assuming the ground heat exchanger as a line source. If the equation is summarized and expressed as a linear relationship, it is expressed as [Equation 1] below.

[Equation 1]

K = Q / (4πL × S)

Where K is the thermal conductivity, Q is the amount of heat injected into the underground heat exchanger, L is the length of the borehole, and S is the slope with time variation of the average temperature.

When the average temperature change curve is calculated using the measured inlet / outlet temperature change, measurement time, and heat injection amount of the ground heat exchanger, the graph as shown in FIG. 2 is converted into a natural log. S in [Equation 1] refers to the slope of the average temperature change curve with respect to logarithmic time as shown in FIG.

The data processor 170 calculates the underground thermal conductivity by applying the method described above. That is, the thermal conductivity (K) is calculated by calculating the temperature change per hour of groundwater based on the data of the temperature sensors 161 and 162 and the heat input of the boiler 141.

The above has been explained with reference to the accompanying drawings of the underground thermal conductivity measuring apparatus according to the present invention, the present invention is not limited to the embodiments and drawings disclosed herein, those skilled in the art within the scope of the technical idea of the present invention Various modifications can be made by

Claims (7)

A first pipe for extracting groundwater from the well;
A second pipe for discharging groundwater to the well;
A first channel having one end and the other end connected to the first and second pipes, respectively;
A heating unit for heating and discharging groundwater introduced into the first flow passage;
A temperature sensor installed at an inlet / outlet side of the first channel and measuring an inlet / outlet temperature of the first channel; And
It includes a data processing unit for calculating the ground thermal conductivity by storing and processing the data measured by the temperature sensor,
The heating unit, a boiler for supplying steam to the second flow path provided on one side of the first flow path, and is installed between the first and second flow paths to exchange heat between the groundwater of the first flow path and the steam of the second flow path. Which includes a heat exchanger,
The first flow passage includes a gas flow passage and a bypass flow passage branched and joined from the fuel flow passage,
The main flow passage and the bypass flow passage are provided with valves for selectively opening the main flow passage and the bypass flow passage, and the main flow passage or the bypass flow passage connects the first and second pipes to be used as a closed measuring device when used as a closed measuring device. Pumps are installed,
Underground thermal conductivity measuring apparatus, characterized in that the first pipe is provided with a submersible pump for raising the groundwater of the well when used as an open measuring device is not connected to the first and second pipe. delete The method of claim 1,
The boiler has the form of an electric steam boiler,
Underground thermal conductivity measuring apparatus, characterized in that the second passage is provided with an electric valve for adjusting the flow rate of steam introduced into the heat exchanger. The method of claim 3,
Underground thermal conductivity measuring apparatus further comprises a control unit for applying a control signal for adjusting the opening degree to the electric valve to adjust the amount of heat input to the heat exchanger. delete delete The method of claim 1,
And the data processing unit calculates thermal conductivity by calculating an hourly temperature change of well groundwater based on the data of the temperature sensor and the heat input of the boiler.

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