KR101587495B1 - Cooling and heating system using ground source - Google Patents

Abstract

The present invention relates to a cooling / heating system using geothermal heat to improve the heat exchange efficiency by increasing the area of a heat exchange pipe buried in an underground. The system is embedded in a predetermined depth from the ground and connected to a customer installed on the ground, And a heat pump connected to the heat exchange pipe for cooling and heating the customer using the heat or condensation heat of the geothermal water supplied through the heat exchange pipe, The heat exchange pipe includes a plurality of donut type couplers which are composed of a water inlet pipe and a water outlet pipe and circulate the geothermal water which is connected to the water inlet pipe of the heat exchange pipe at regular intervals and is received through the water inlet pipe .

Description

{COOLING AND HEATING SYSTEM USING GROUND SOURCE}

The present invention relates to a cooling / heating system using geothermal heat, and more particularly to a cooling / heating system using geothermal heat so as to increase heat exchange efficiency by increasing the cross sectional area of a heat exchange pipe.

Generally, energy sources used for domestic and industrial heating and cooling include fossil fuels such as petroleum and natural gas, or nuclear fuel. The use of such energy sources not only causes the main cause of environmental pollution, but also has a limited amount of reserves. It is actively proceeding.

As energy sources used for heating and cooling, fossil fuels such as coal, oil, and natural gas are used, or energy produced by using these fossil fuels or nuclear power is mainly used.

However, since fossil fuels have a disadvantage of polluting the water quality and the environment due to various pollutants generated in the combustion process, in recent years, development of alternative energy capable of replacing them has been actively carried out.

Among these alternative energies, studies on wind power, solar heat, geothermal energy, etc., which have infinite energy sources, are being used, and these energy sources have the advantage of obtaining energy without affecting air pollution and climate change On the other hand, the energy density is very low.

In particular, in order to obtain energy using wind power and solar heat, a large area must be secured along with the limit of the installation site, and these devices have a small energy production capacity per unit unit and a large installation and maintenance cost.

Geothermal energy, which is part of alternative energy, can be used for power generation by using geothermal energy in deep underground, and it can be applied to heating and cooling system by using geothermal heat at 10 ~ 20 ℃. It is possible to save energy by 40% or more compared with the conventional heating and cooling apparatus, and it is known that the energy generation cost can be reduced by 40 to 70%.

The heating and cooling system using geothermal, which is an electric device using natural heat storage such as ground water for the purpose of cooling and heating the building using the geothermal heat, is equipped with an underground heat exchanger so that heat is released to the ground during the summer season by the heat exchanger, By absorbing heat, the cooling and heating performance is not lowered due to the geothermal temperature maintained at a constant temperature from 10 to 20 ° C throughout the year, and stable operation is possible.

Therefore, there are many heating and cooling devices using geothermal energy that are relatively inexpensive to install and maintain. This is a technology using the thermal energy of the ground, which is 10 to 20 ° C in temperature.

The conventional cooling and heating system using geothermal heat is composed of a heat exchange pipe for recovering geothermal heat and a heat pump for cooling and heating by moving the geothermal heat recovered from the heat exchange pipe to a required place.

1 is a schematic view showing a conventional air conditioning system using geothermal heat.

As shown in FIG. 1, in the conventional cooling / heating system using geothermal heat, a plurality of boreholes are excavated at a depth of 150 to 200 m or more in the soil layer at the land side and heat exchange And the pipe 20 is buried.

The geothermal water supplied through the heat exchange pipe (20) is provided with a heat pump (30) for moving to a required customer (10) for cooling and heating.

The conventional geothermal cooling and heating system constructed as described above performs geothermal heat as a heat source and receives geothermal water having a constant temperature through U-shaped heat exchange pipes 20 buried in the ground, .

The cooling / heating operation includes circulation cycles with the U-shaped heat exchange pipes 20 and connected to the evaporator and the condenser. The geothermal water obtained from the cooling / heating heat pump 30 is cooled by the cooling / heating heat pump 30, And a circulation cycle, and is moved to a cooling / heating place where a connected heat exchanger (not shown) is installed to perform cooling and heating by heat exchange with the outside air or supply hot water.

The heat exchange pipe 20 is made of U (polyethylene) (HDPE) material.

However, in the conventional cooling / heating system using geothermal heat, since the heat exchange pipe is made of U-shaped polyethylene material, sufficient heat exchange can not be performed and the heat exchange efficiency is low. Therefore, conventionally, in order to increase the heat exchange efficiency, the construction depth of the heat exchange pipe has to be deeply set at a maximum of 150 to 200 m or more, and the cost of raw materials has increased.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a cooling / heating system using geothermal heat to improve the heat exchange efficiency by increasing the area of a heat exchange pipe buried underground.

In order to accomplish the above object, the present invention provides a cooling / heating system using geothermal heat, which is embedded at a predetermined depth from the ground, connected to a customer installed on the ground, absorbs geothermal heat through geothermal water in the ground, And a heat pump connected to the heat exchange pipe and cooling / heating the customer using the heat or condensation heat of the geothermal water supplied through the heat exchange pipe. The heat exchange pipe includes a water inlet pipe and a water outlet pipe And a plurality of donut-type couplers connected to the inlet pipe of the heat exchange pipe at regular intervals and circulating the geothermal water received through the inlet pipe.

The cooling / heating system using geothermal according to the present invention has the following effects.

That is, the heat exchange efficiency can be improved by increasing the area of the heat exchange pipe buried in the underground.

1 is a schematic view showing a conventional cooling / heating system using geothermal heat
Fig. 2 is a schematic view of a cooling / heating system using geothermal heat according to the present invention
FIG. 3 is a perspective view showing a heat exchange pipe in the cooling / heating system using the geothermal heat of FIG.
4 is a view showing a donut-shaped coupler connected to the inlet pipe of the heat exchange pipe of FIG. 3
5 is a perspective view showing a state in which the donut-type coupler of Fig. 4 is connected to the inlet pipe; Fig.

Hereinafter, a geothermal heating / cooling system according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

In addition, the same or corresponding components are denoted by the same reference numerals regardless of the reference numerals, and redundant explanations thereof will be omitted. For convenience of explanation, the size and shape of each constituent member shown may be exaggerated or reduced have.

FIG. 2 is a schematic view of a cooling / heating system using geothermal according to the present invention, and FIG. 3 is a perspective view showing a heat exchange pipe in the cooling / heating system using the geothermal heat of FIG.

4 is a view showing a donut-type coupler connected to a water inlet pipe of the heat exchange pipe of FIG. 3, and FIG. 5 is a perspective view showing a state where the donut-type coupler of FIG. 4 is connected to a water inlet pipe.

2 and 3, the cooling / heating system 100 using geothermal according to the present invention includes a customer 110, a heat pump 120, a heat exchange pipe 130, and a heat storage tank 140 have.

Here, the customer 110 means a space where people and livestock live and live while having a certain size, or a space where they work for a certain period of time such as a company or a government office.

The heat pump 120 is a well-known technique, which is not specifically shown and described, but includes an evaporator for evaporating the refrigerant, a compressor for compressing the refrigerant evaporated from the evaporator and discharging the refrigerant at high temperature and high pressure, And a condenser and an expansion valve in which the discharged refrigerant flows and is condensed.

That is, the heat pump 120 refers to a cooling / heating device that transfers a low-temperature heat source to a high temperature or transfers a high-temperature heat source to a low temperature by using heat or condensation heat of a refrigerant. The heat pump 120 includes an outdoor unit having a compressor and an outdoor exchanger, and an indoor unit including an expansion valve and an indoor exchanger.

The heat exchange pipe 130 is formed in a U-shape embedded in the ground. The heat exchange pipe 130 is inserted into the ground to pump the geothermal water to the heat pump 120 or the heat storage tank 140.

The heat exchange pipe 130 is formed by drilling an earth surface at a depth of 100 to 150 M to form a borehole, and a heat exchange pipe 130 including a U-shaped inlet pipe and a water pipe is inserted into the borehole.

Meanwhile, among the U-shaped heat exchange pipes 130 constituting the heat exchange pipe 130, the diameters of the water inlet pipe and the water outlet pipe may be different, so that the flow rate of the geothermal water may be different.

For example, the diameter of the water inlet pipe used for cooling and heating in the customer 110 may be smaller than the diameter of the water outlet pipe to which geothermal water flows into the heat pump 120 or the heat storage tank 140 The flow rate of the geothermal water supplied to the heat pump 120 or the thermal storage tank 140 can be decreased to lower or raise the temperature of the geothermal water.

As the geothermal heat is circulated along the inside of the heat exchange pipe 130 by the pump, the heat exchange pipe 130 absorbs heat from the ground through heat exchange with the ground, thereby recovering the geothermal heat, or the heat pump 120 or the heat storage tank 140 ) Will supply geothermal water at a certain temperature (15 ~ 21 ℃).

For example, when the temperature of the geothermal water flowing from the heat exchange pipe 130 is 10 ° C, the thermal storage tank 140 increases the temperature of the geothermal water to 15 to 21 ° C by heating and supplies the geothermal water to the heat pump 120 When the temperature is 25 캜, the temperature is lowered to a temperature of 15 캜 to 21 캜 and then supplied to the heat pump 120.

And a plurality of radiating fins radially extending along inner and outer surfaces of the heat exchange pipe 130. The plurality of radiating fins expand the inner and outer surface areas of the heat exchange pipe 130 as much as possible, The heat exchange efficiency with the geothermal heat can be maximized.

The heat exchange pipe 130 includes a water inlet pipe 131 and a water outlet pipe 132 and increases the cross sectional area of the heat exchange pipe 130 to the water inlet pipe 131 of the heat exchange pipe 130 A plurality of donut type couplers 150 are connected to increase the thermal conductivity.

The donut type coupler 150 is connected to the water inlet pipe 131 of the heat exchange pipe 130 through the connection socket 160 at a predetermined interval and is connected to the ground water pipe Increase the thermal conductivity by increasing the cross-sectional area while circulating.

4 and 5, a portion of the donut-type coupler 150 connected to the inlet pipe 131 is connected to an upper circular pipe 151 having a predetermined interval at the upper and lower ends, respectively, And a lower circular pipe 152. A plurality of linear pipes 153 are installed at regular intervals between the upper circular pipe 151 and the lower circular pipe 152. [

The geothermal water flowing into the ground through the water inlet pipe 131 circulates inside the upper circular pipe 151 constituting the donut type coupler 150 and then flows into the straight pipe 153 and the lower circular pipe 152, And then supplied to the heat pump 120 or the heat storage tank 140 through the water pipe 132. [

The outflow pipe 132 is formed in a straight shape passing through between the donut-shaped couplers 150 connected to the intake pipe 131 at a predetermined interval.

In general, the thermal conductivity of a heat exchange pipe is proportional to the cross-sectional area and inversely proportional to thickness.

The outer diameter of the heat exchange pipe according to the prior art is 34 mm, the outer diameter of the heat exchange pipe according to the present invention is 21.5 mm x n (where n is the number of the donut type couplers) As follows.

That is, the conventional heat exchange pipe has 34 × 3.14 × 6 = 640.56, and the heat exchange pipe according to the present invention has 21.5 × 3.14 × 6 × n = 405.06 × n. In the present invention, + {(n-2) x 60%}.

In addition, the thickness of the heat exchange pipe according to the present invention is 3.5T, whereas the thickness of the heat exchange pipe according to the present invention is 2.5T, which can reduce the present invention by about 29%.

The heat storage tank 140 stores geothermal water introduced from the heat exchange pipe 130 or stores geothermal water heat-exchanged by the heat pump 120. The heat storage pipe 140 is connected to the heat exchange pipe 130 And is connected to the heat pump 120.

The geothermal water flowing into the heat storage tank 140 through the heat exchange pipe 130 is heated or cooled to a predetermined temperature and supplied to the heat pump 120.

For example, when a temperature monitoring sensor (not shown) is attached to the thermal storage tank 140 and the temperature of the geothermal water introduced into the thermal storage tank 140 through the temperature detection sensor is less than 15 degrees, And discharges the geothermal water to 15 degrees or more. When the temperature is in the range of 15 to 30 degrees, the geothermal water is directly discharged without operating the thermal storage tank 140 and used for heating.

Accordingly, the temperature of the geothermal water supplied from the heat exchange pipe 130 to the thermal storage tank 140 is compensated to 15 to 21 ° C and supplied to the heat pump 120, thereby reducing the operation time of the heat pump 120, It is possible to optimize the cooling / heating efficiency.

Here, the thermal storage tank 140 measures the temperature of the geothermal water flowing into the ground, and when the geothermal water temperature is lower or higher than the set value, the temperature of the geothermal water is compensated to the temperature of 15 to 21 ° C through heating or cooling To the heat pump (120).

At this time, the thermal storage tank 140 normally uses the power supplied from a photovoltaic power generation device (not shown), but when the photovoltaic power generation device does not generate electricity, the stored power or electric power system The supplied power source is used.

In addition, the thermal storage tank 140 can reduce power consumption by itself generating and using electric power through solar power generation during the day when solar power generation is possible, and when installed in a place such as a government office that works five days a week, It is operated as surplus energy of PV power generated from photovoltaic power generation system or general grid electricity, and energy can be saved by using stored energy.

The photovoltaic device generates direct current electricity from a solar cell array that receives sunlight and converts the direct current electricity into an alternating current electricity through an inverter. The alternating current electricity converted through the inverter is supplied to a power system So that the power can be selectively used.

If the heat storage tank 140 does not operate, the electric energy generated from the solar power generator is charged into an energy storage device (not shown) and used as needed.

The heat pump 120 and the heat storage tank 140 are configured to communicate with each other to maintain the geothermal water at 15 to 21 ° C. The heat storage tank 140 is an additional element in the embodiment of the present invention and can be omitted as necessary and supplied to the heat pump 120 or the thermal storage tank 140 through the heat exchange pipe 130 have.

In addition, according to the present invention, the operation cost of the heat pump 120 can be reduced by allowing the heat pump 120 to operate according to the set temperature of the heat storage tank 140.

In addition, the present invention uses electric energy directly through solar power generation using natural solar energy as an operating energy source, and when the solar power generation is not performed, the electric power source is directly supplied from the electric power system of KEPCO. When the cooling / heating system is not operated, the electric energy generated through the solar power generation is stored in a separate energy storage device and is used as an energy source when necessary, so that power consumption can be minimized.

Further, since the present invention requires only a depth of 100M or less when drilling the ground, it is possible to simplify drilling work with less restriction on the place.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Will be apparent to those of ordinary skill in the art.

110: customer demand 120: heat pump
130: Heat exchange pipe 140: Heat storage tank
150: Donut coupler

Claims (6)

A heat exchange pipe embedded in a predetermined depth from the ground to connect to a customer installed on the ground and absorbing geothermal heat through geothermal water in the ground or releasing heat to the ground;
And a heat pump connected to the heat exchange pipe and cooling / heating the customer using the heat or condensation heat of the geothermal water supplied through the heat exchange pipe,
The heat exchange pipe includes a plurality of donut-type couplers which are composed of a water inlet pipe and a water outlet pipe and circulate the geothermal water which is connected to the water inlet pipe of the heat exchange pipe at regular intervals and is received through the water inlet pipe, Respectively,
The toroidal type coupler is composed of an upper circular pipe and a lower circular pipe having a predetermined interval at the upper and lower ends, respectively, and a plurality of linear pipes having a constant interval passing through between the upper circular pipe and the lower circular pipe,
Wherein the water pipe is formed in a straight shape passing through between the donut type couplers connected to the water pipe at a predetermined interval. delete The method according to claim 1, wherein the geothermal water flowing into the ground through the inlet pipe is circulated inside the upper circular pipe constituting the donut type coupler and circulated to the straight pipe and the lower circular pipe, And the pump is supplied to the heating / cooling system. delete The system of claim 1, wherein the donut-type coupler is connected to the inlet pipe through a connection socket. The system of claim 1, further comprising a heat storage tank connected to the heat exchange pipe and the heat pump to supply refrigerant to the heat pump at a predetermined temperature.

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