KR101092058B1 - A method for controlling uniform flow amounts of Geothermal heat exchanger - Google Patents

Abstract

The uniform flow control method of the underground heat exchanger is to arrange the pipes of the underground heat exchanger pipe in parallel, and to equalize the resistance of the flow of the circulating fluid by the intermediate flow distribution header provided with the pressure gauge and the valve, so that the ground heat exchanger is located by position. By distributing the flow rate of the circulating fluid equally, heat transfer can be effectively performed.

The method for controlling the uniform flow rate of the underground heat exchanger according to the present invention is arranged in a parallel manner such that the underground heat exchanger pipe is composed of a branched U pipe, a terminal U pipe and a main pipe leading to a manhole, and the branched U pipe and the terminal U pipe. Characterized in that the distance between the pipes are constantly.

Unbalance, flow rate, pipe, underground heat exchanger, valve, resistance

Description

A method for controlling uniform flow amounts of Geothermal heat exchanger}

The present invention relates to a method for controlling the uniform flow rate of a geothermal trench pipe of a circulating fluid circulating in an underground heat exchanger, in particular, a method for controlling the uniform flow rate in the shape of a trench pipe and a header for distributing intermediate flow rate in a manhole.

Cooling and heating technology using geothermal energy was first developed in the 1950s and is widely used in various countries including the United States, Europe and Asia. To use geothermal energy, underground heat exchangers must be installed underground. Underground heat exchangers are vertically buried 100 to 200 m vertically, for example, vertically buried polyethylene pipes, and horizontally buried horizontally from 1.25 m to 1.5 m horizontally, depending on the method of laying the pipes. . There is an underground water type that connects pipes directly to the ground water.

Vertical underground heat exchanger is the most common type, has the high reliability, suitable for the case of narrow construction site and has the advantage of excellent thermal performance, there is a disadvantage that high construction cost.

Horizontal underground heat exchanger is low in construction cost, easy to install and simple to maintain, but requires a large installation site, lacks thermal performance compared to vertical type, and cannot be installed in downtown, so there are few construction cases in Korea.

Groundwater type underground heat exchangers connect pipes directly to groundwater, so construction costs are low, thermal performance is excellent, and the installation site is narrow.However, there is a need for continuous groundwater quantity, the groundwater level is low, and it is applicable only in some areas. Water may break the equipment. The groundwater underground heat exchanger has some domestic construction examples recently.

Pipe selection of heat exchangers should be made of polyethylene or polybutylene which can be thermally fused in consideration of service life, maintenance costs, energy requirements of pumps and local site conditions. Pipe diameters should consider power consumption and heat transfer simultaneously. In other words, if the pipe diameter is increased, the power consumption is reduced, but the heat transfer is reduced.

The construction of the pipe of the underground heat exchanger is usually performed by the following procedure with reference to Korean Patent No. 10-0654152, which is patented by the present applicant.

The installation of underground heat exchanger excavates boreholes 50m ~ 200m deep at predetermined intervals and winds one or two of each borehole to embed a U-shaped pipe.After installation, each borehole is an impermeable material. Fill with phosphorus bentonite or cement and grout. In the grouting process, the borehole is filled with a special material to prevent the inflow of surface water into the aquifer or the infiltration of adjacent aquifers into the water. In general, grouting materials have lower heat transfer properties and are more expensive than ordinary backfills. If local regulations are allowed, the grouting of the upper 6 m to 10 m of the borehole is sufficient to prevent surface water ingress, and high geothermal heat exchanger efficiency and low unit cost are possible. After filling and grouting, the vertical pipes connect with the header pipes. The header pipe serves to transfer the underground heat exchanger heat transfer fluid to the heat pump. Vertical circulation systems are generally more expensive than horizontal ones, but the deeper they are, the more efficient the installation pipes are.

In a typical horizontal geothermal heat exchange system, a geothermal heat exchanger for recovering geothermal heat, which is buried to a predetermined depth in the ground, is composed of heat exchanger pipes having high thermal conductivity such as polyethylene pipe or copper pipe, and internal geothermal energy and It has a structure filled with a circulating fluid (refrigerant) for heat exchange.

The horizontal underground heat exchanger is installed in the ground in an approximately horizontal direction to form a closed circuit, and both ends of the inlet side and the outlet side are connected by a heat pump.

The installation of such a horizontal underground heat exchanger is to excavate and install the site to install the underground heat exchanger to a predetermined depth, and is usually excavated and installed about 2m from the ground surface.

Horizontal underground heat exchanger pipes are also embedded in underground foundation slabs.

In order to supply geothermal heat to common households, such as apartments, a large number of pipes, for example 20, are installed in the ground and their inlet and outlet are connected to heat pipes connected to the header pipes installed in the manhole. .

Underground heat exchanger pipes are installed in underground, foundation slabs, underground continuous walls, etc., but their diameters can be constant, but not their length or height. Therefore, the length and height of the underground heat exchanger pipes are different.

Underground heat exchanger pipes do not have a constant resistance of the flow of the circulating fluid due to length, thickness, height, etc., and the flow rate of the circulating fluid is unevenly distributed according to the locations of the underground heat exchanger, thereby making it difficult to effectively conduct heat transfer.

It is an object of the present invention to arrange underground pipes of underground heat exchanger pipes in parallel, and to install a header pipe between the heat pump and the underground heat exchanger pipe to solve the imbalance distribution of the circulating fluid, thereby increasing the thermal efficiency of the geothermal heat exchanger. It is to provide an equal flow rate control method of the group.

An equal flow control method for an underground heat exchanger, wherein in the first embodiment, the underground heat exchanger pipe is arranged in parallel so as to be composed of a branch U pipe, a terminal U pipe, and a main pipe leading to a manhole, and the branch U pipe and the terminal U The distance between the pipes is constantly piped, and the main pipe and the branch U pipe are connected in a T shape.

In the second embodiment, the branch U pipe closest to the manhole and the far end U pipe are connected to one main pipe so that the length of the pipe drawn into the manhole of the underground heat exchanger pipe is constant, and the second branch U pipe close to the manhole is connected. And the second far end U pipe to one main pipe, and the third branch U pipe close to the manhole and the third far end U pipe to one main pipe to keep the pipes constant. The main pipe and the branch U pipe are connected in a T shape.

In the third embodiment, each of the underground heat exchanger pipes is connected to an intermediate flow distribution header in a manhole, and controls the flow rate of a pressure gauge and a circulating fluid for checking the pressure of each underground heat exchanger pipe to the intermediate flow distribution header. A valve is installed, and the valve is adjusted by looking at the pressure gauge installed in the header for distributing the intermediate flow rate, thereby adjusting the uniform flow rate of the circulating fluid regardless of the resistance difference according to each underground heat exchanger pipe. Or an EPS valve that is automatically controlled.

By equalizing the resistance of the flow of the circulating fluid by the piping method of the geothermal heat exchanger pipe and the intermediate flow distribution header provided with the pressure gauge and the valve, the flow rate of the circulating fluid can be evenly distributed according to the location of the underground heat exchanger to increase the heat transfer efficiency. .

Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

1 illustrates the piping (trench) of a ground heat exchanger pipe of a preferred embodiment of the present invention.

In FIG. 1, underground heat exchanger pipes (60) are gathered in manholes (50), and each underground heat exchanger pipe (60) is a main pipe leading to branched U pipes (61) and end U pipes (62) and manholes (50). It consists of (63). The main pipe 63 and the branch U pipe 61 have a T-shape. The underground heat exchanger pipe 60 is arranged in parallel. This is shown in Figure 1A. This parallel method can distribute the fluid evenly compared with the serial method shown in FIG. 1B. In addition, in consideration of the thermal efficiency and the resistance of the pipes, the pipes are arranged so that the separation distance between each branch U pipe 61 and each end pipe 62 is substantially constant. That is, the distance between the end pipe 62 'and the branch pipe 61' of the first underground heat exchanger pipe 60 'and the branch pipe 61' and the second underground heat exchange of the first underground heat exchanger pipe 60 '. The distance of the end pipe 62 "of the base pipe 60" is constant.

FIG. 2 shows yet another preferred embodiment, the branch U pipe 61 closest to the manhole and the farthest end U pipe (ie, the length of the pipe leading into the manhole of each underground heat exchanger pipe 60). 62) and one main pipe 63, and the second closest branch U pipe 61 'from the manhole and the second far end U pipe 62' to one main pipe 63 ', , Connect the third closest branch U-pipe (61 ") and the third far-end U pipe (62") from the manhole into one main pipe (63 "). This allows pipes (60, 60 ', 60"). The overall length of) is almost constant, so the resistance of the pipe is almost the same, which can improve the heat transfer efficiency.

As shown in FIG. 1 and FIG. 2, the circulating fluid is firstly distributed evenly according to the piping method of the underground heat exchanger pipe. However, when this is insufficient, the intermediate flow distribution header is used to evenly distribute the circulating fluid. The pressure gauge 71 and the valve 72 are provided at 70. 3, each of the underground heat exchanger pipes 60 is connected to an intermediate flow distribution header 70 in the manhole 50, and each of the underground heat exchanger pipes is connected to the intermediate flow distribution header 70. A pressure gauge 71 for checking the pressure at 60 and a valve 72 for controlling the flow rate of the circulating fluid are provided. Since the length and height of each underground heat exchanger pipe 60 are different, the resistance and pressure of each underground heat exchanger pipe 60 are different from each other. The pressure gauge 71 installed in the intermediate flow distribution header 70 adjusts the valve 72 to adjust the equal flow rate of the circulating fluid regardless of the resistance difference according to each underground heat exchanger pipe 60. 70) to the heat pump.

The valve 72 may be a ball valve that can be controlled manually, or may be an EPS valve (Electronic Power Steering Valves) that can be controlled automatically.

Although various features and advantages of the invention have been described in detail in the foregoing description with the detailed configuration and functions of the invention, these are for illustrative purposes only. Changes, in particular shapes, sizes and arrangements of parts, may occur without departing from the scope of the invention and should be construed in a broader sense by the appended claims.

1 is a perspective view of a first preferred embodiment of the present invention.

1A is a parallel arrangement diagram of an underground heat exchanger pipe.

1b is a series arrangement diagram of the underground heat exchanger pipe.

2 is a perspective view of a second preferred embodiment of the present invention.

 Figure 3 is a detailed view of the intermediate flow distribution header in a third preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: underground heat exchanger

20: heat pump

60: pipe

70: header for medium flow distribution

71: pressure gauge

72: valve

Claims (6)

As a uniform flow rate control method of underground heat exchanger, The underground heat exchanger pipe (60) is arranged in parallel so that it consists of the branch U pipe (61), the end U pipe (62) and the main pipe (63) leading to the manhole (50). The distance between the end U pipe (62) is a constant pipe, the main pipe and the branch U pipe is T-shaped, characterized in that the flow rate control method of the underground heat exchanger. delete As a uniform flow rate control method of underground heat exchanger, The branch U pipe 61 closest to the manhole and the far end U pipe 62 are connected to one main pipe 63 so that the length of the pipe leading into the manhole of the underground heat exchanger pipe 60 is constant. The second branch U pipe 61 'closest to the manhole and the second far end U pipe 62' are connected by one main pipe 63 ', and the third branch U pipe 61 " The first far end U pipe 62 "is connected to one main pipe 63" to keep the lengths of the pipes constant, and the main pipe and the branch U pipe are T-shaped. Flow control method. As a uniform flow rate control method of underground heat exchanger, Each of the underground heat exchanger pipes is connected to an intermediate flow distribution header in the manhole, and the pressure gauge 71 and the flow rate of the circulating fluid for checking the pressure of each underground heat exchanger pipe 60 to the intermediate flow distribution header 70. Install the valve 72 to control the The valve 72 is adjusted by looking at the pressure gauge 71 installed in the intermediate flow distribution header 70 to adjust the uniform flow rate of the circulating fluid regardless of the resistance difference according to each underground heat exchanger pipe 60. Equal flow control method of the underground heat exchanger, characterized in that the ball valve to control manually, or EPS valve to control automatically. delete delete

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