Aquifer heat storage system and aquifer heat storage method

Abstract

To keep water passing performance of wells straddling a plurality of aquifers.SOLUTION: An aquifer heat storage system 100 comprises: a first well 10a and a second well 10b formed so as to straddle a first aquifer A1 and a second aquifer A2, and for taking in groundwater from the first aquifer A1 and the second aquifer A2; water shielding layers 21a, 22a, 23a, 21b, 22b, and 23b provided in the first well 10a and the second well 10b, and for forming first chambers 11a and 11b leading to the first aquifer A1, and second chambers 12a and 12b leading to the second aquifer A2, inside each of the first well 10a and the second well 10b; a first pump 41a for pumping up groundwater from the first chamber 11a of the first well 10a, and sending it to the first chamber 11b of the second well 10b through a heat exchange part 1; and a second pump 42a for pumping up groundwater from the second chamber 12a of the first well 10a, and sending it to the second chamber 12b of the second well 10b through the heat exchange part 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an aquifer thermal storage system and aquifer thermal storage method. [Background technology]

[0002] An aquifer thermal storage system has been proposed that uses groundwater in an aquifer to heat and cool the interior of a building (Patent Document 1).

[0003] Patent Document 1 discloses that two wells are provided in the ground, and groundwater is pumped from the wells using a pump and directed to a heat exchanger. During cooling, groundwater pumped from an aquifer through one of the two wells is used to cool a heat transfer medium. The groundwater heated by heat exchange with the heat transfer medium is injected into the other well and returned to the aquifer. During heating, groundwater pumped from the aquifer through the other well is used to heat the heat transfer medium. The groundwater cooled by heat exchange with the heat transfer medium is injected into one of the wells and returned to the aquifer. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-54857 Summary of the Invention [Problem to be solved by the invention]

[0005] In the aquifer thermal storage system disclosed in Patent Document 1, it is desired to increase the amount of groundwater pumped from the aquifer. One possible means for increasing the amount of groundwater pumped is to form wells across multiple aquifers.

[0006] However, in wells that cross multiple aquifers, the groundwater from these aquifers can mix and cause chemical changes, which can lead to clogging of the well and a decrease in its water flow capacity over time.

[0007] The present invention aims to maintain the water flow performance of a well that crosses multiple aquifers. [Means for solving the problem]

[0008] The present invention is an aquifer thermal storage system that pumps groundwater from a first aquifer and a second aquifer and returns it to the first aquifer and the second aquifer, respectively, through a heat exchanger. The system comprises: a first well and a second well formed across the first aquifer and that take in groundwater from the first aquifer and the second aquifer; water shielding layers provided in the first well and the second well that form a first chamber communicating with the first aquifer and a second chamber communicating with the second aquifer within each of the first and second wells; a first pump that pumps groundwater from the first chamber of the first well and sends it to the first chamber of the second well through the heat exchanger; and a second pump that pumps groundwater from the second chamber of the first well and sends it to the second chamber of the second well through the heat exchanger.

[0009] The present invention also provides an aquifer heat storage method that uses an aquifer heat storage system to pump groundwater from a first aquifer and a second aquifer and return the groundwater to the first aquifer and the second aquifer, respectively, through a heat exchanger. The aquifer heat storage system includes: a first well and a second well that are formed across the first aquifer and the second aquifer and that take in groundwater from the first aquifer and the second aquifer; and water shielding layers that are provided in the first well and the second well and that form, within each of the first and second wells, a first chamber that communicates with the first aquifer and a second chamber that communicates with the second aquifer. The aquifer heat storage method pumps groundwater from the first chamber of the first well and delivers it to the first chamber of the second well through the heat exchanger, and pumps groundwater from the second chamber of the first well and delivers it to the second chamber of the second well through the heat exchanger. [Effects of the Invention]

[0010] According to the present invention, the water flow performance of a well that crosses multiple aquifers can be maintained. [Brief explanation of the drawings]

[0011] [Figure 1]1 is a schematic cross-sectional view of an aquifer thermal storage system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II shown in FIG. [Figure 3] FIG. 2 is a cross-sectional view taken along line III-III shown in FIG. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV shown in FIG. [Figure 5] FIG. 2 is a cross-sectional view taken along line VV shown in FIG. [Figure 6] 2(a) is a perspective view of the first cold well spacer shown in FIG. 1, and FIG. 2(b) is a perspective view of the second cold well spacer shown in FIG. [Figure 7] FIG. 10 is a perspective view of a first cold well spacer according to a modified example of the embodiment of the present invention. [Figure 8] 8 is a cross-sectional view showing a state in which first to fourth cold well lifting pipes are held using the first cold well spacer shown in FIG. 7. FIG. [Figure 9] FIG. 10 is a perspective view of a first cold well spacer according to another modified example of the embodiment of the present invention. [Figure 10] 10 is a cross-sectional view showing a state in which first to fourth cold well lifting pipes are held using the first cold well spacer shown in FIG. 9. FIG. [Figure 11] FIG. 10 is a perspective view of a fourth cold well spacer according to a modified example of the embodiment of the present invention. [Figure 12] FIG. 12 is a cross-sectional view showing a state in which a fourth cold well riser pipe is held using the fourth cold well spacer shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] An aquifer thermal storage system 100 according to an embodiment of the present invention will be described below with reference to the drawings.

[0013] Figure 1 is a schematic cross-sectional view of an aquifer thermal storage system 100. The aquifer thermal storage system 100 pumps up groundwater and returns it to the ground through a heat exchange unit 1. The heat exchange unit 1 includes a pipe 2 through which a heat medium flows, and cools and heats the heat medium using groundwater to provide heating and cooling for the inside of a building (not shown).

[0014] 1 shows an example in which an aquifer thermal storage system 100 is constructed on ground containing four aquifers A1 to A4. The four aquifers A1 to A4 are located in this order from the ground surface. Hereinafter, the aquifers A1 to A4 will be referred to as the first aquifer A1, the second aquifer A2, the third aquifer A3, and the fourth aquifer A4, respectively. Furthermore, when referring to the four aquifers A1 to A4 collectively, they will simply be referred to as "aquifer A."

[0015] The aquifer thermal storage system 100 includes a first well 10a and a second well 10b formed across the first to fourth aquifers A1 to A4. The first well 10a draws groundwater from the first to fourth aquifers A1 to A4. Specifically, the first well 10a is formed by inserting a cylindrical screen (not shown) into a vertical hole formed in the ground. The screen has multiple holes (not shown) formed at positions corresponding to the depths of the first to fourth aquifers A1 to A4, and groundwater is drawn into the first well 10a from the first to fourth aquifers A1 to A4 through the holes. The second well 10b has a structure similar to that of the first well 10a and draws groundwater from the first to fourth aquifers A1 to A4.

[0016] During cooling in the summer, the aquifer thermal storage system 100 pumps up groundwater from the first well 10a, uses it to cool the heat medium in the heat exchanger 1, and then injects it into the second well 10b. Because the groundwater injected into the second well 10b is warmed by heat exchange with the heat medium, heat is stored around the second well 10b.

[0017] During heating in winter, the aquifer thermal storage system 100 pumps up groundwater from the second well 10b and uses it to heat the heat medium in the heat exchanger 1. Because the groundwater in the second well 10b is heated during cooling, it can efficiently heat the heat medium during heating.

[0018] The groundwater pumped up during heating is used to heat the heat medium and then injected into the first well 10a. The groundwater injected into the first well 10a is cooled by heat exchange with the heat medium, so the area around the first well 10a is cooled. Therefore, when groundwater is pumped from the first well 10a during cooling, the heat medium can be cooled efficiently.

[0019] In this way, in the aquifer thermal storage system 100, by alternating between cooling and heating seasons, the heated groundwater discharged in the summer can be used as a heat source for heating in the winter, and the cooled groundwater discharged in the winter can be used as a heat source for cooling as described below, thereby enabling efficient use of thermal energy. Note that during cooling, groundwater may be pumped from the second well 10b and injected into the first well 10a, and during heating, groundwater may be pumped from the first well 10a and injected into the second well 10b.

[0020] In the following, we will explain the case where groundwater is pumped up from the first well 10a and injected into the second well 10b during cooling, and groundwater is pumped up from the second well 10b and injected into the first well 10a during heating. In the following, the first well 10a from which groundwater is pumped up during cooling may also be referred to as the "cold well 10a," and the second well 10b from which groundwater is pumped up during heating may also be referred to as the "hot well 10b."

[0021] In the aquifer thermal storage system 100, the cold well 10a and the hot well 10b are formed across a plurality of aquifers A. This allows the amount of groundwater that can be pumped up to be increased.

[0022] In the cold well 10a, cold well impermeable layers 21a to 25a are provided in this order from the ground surface. A first cold well chamber 11a is formed inside the cold well 10a by the cold well impermeable layers 21a and 22a. The first cold well chamber 11a is connected to the first aquifer A1, and groundwater in the first aquifer A1 flows into the first cold well chamber 11a. Similarly, a second cold well chamber 12a connected to the second aquifer A2 is formed inside the cold well 10a by the cold well impermeable layers 22a and 23a. A third cold well chamber 13a connected to the third aquifer A3 is formed inside the cold well 10a by the cold well impermeable layers 23a and 24a. A fourth cold well chamber 14a connected to the fourth aquifer A4 is formed inside the cold well 10a by the cold well impermeable layers 24a and 25a.

[0023] In the hot well 10b, hot well water shielding layers 21b to 25b are provided in this order from the ground surface. A first hot well chamber 11b is formed inside the hot well 10b by the hot well water shielding layers 21b and 22b. The first hot well chamber 11b is connected to the first aquifer A1, and groundwater in the first aquifer A1 flows into the first hot well chamber 11b. Similarly, a second hot well chamber 12b connected to the second aquifer A2 is formed inside the hot well 10b by the hot well water shielding layers 22b and 23b. A third hot well chamber 13b connected to the third aquifer A3 is formed inside the hot well 10b by the hot well water shielding layers 23b and 24b. A fourth hot well chamber 14b connected to the fourth aquifer A4 is formed inside the hot well 10b by the hot well water shielding layers 24b and 25b.

[0024] The cold well water shielding layers 21a to 25a and the hot well water shielding layers 21b to 25b are, for example, clay layers.

[0025] Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a cross-sectional view taken along line III-III in Fig. 1. Fig. 4 is a cross-sectional view taken along line IV-IV in Fig. 1. Fig. 5 is a cross-sectional view taken along line IID-IID in Fig. 1.

[0026] As shown in Figures 1 to 5, first and second to fourth cold well pumping pipes 31a to 34a are provided inside the cold well 10a. The first cold well pumping pipe 31a is inserted into the first cold well chamber 11a, and the lower end opening (first opening) of the first cold well pumping pipe 31a is located inside the first cold well chamber 11a. Therefore, groundwater in the first aquifer A1 flows into the first cold well pumping pipe 31a through the first cold well chamber 11a. In other words, the first cold well pumping pipe 31a forms a flow path for groundwater pumped up from the first cold well chamber 11a. Similarly, the second to fourth cold well pumping pipes 32a to 34a are inserted into the second to fourth cold well chambers 12a to 14a, respectively, and the lower end openings (second to fourth openings) of the second to fourth cold well pumping pipes 32a to 34a are located within the second to fourth cold well chambers 12a to 14a, respectively, forming flow paths for the groundwater pumped up from the second to fourth cold well chambers 12a to 14a.

[0027] First to fourth hot well pumping pipes 31b to 34b are provided inside the hot well 10b. The first hot well pumping pipe 31b is inserted into the first hot well chamber 11b, and the lower end opening (first opening) of the first hot well pumping pipe 31b is located inside the first hot well chamber 11b. Therefore, groundwater in the first aquifer A1 flows into the first hot well pumping pipe 31b through the first hot well chamber 11b. In other words, the first hot well pumping pipe 31b forms a flow path for groundwater pumped up from the first hot well chamber 11b. Similarly, the second to fourth hot well pumping pipes 32b to 34b are inserted into the second to fourth hot well chambers 12b to 14b, respectively, and the lower end openings (second to fourth openings) of the second to fourth hot well pumping pipes 32b to 34b are located within the second to fourth hot well chambers 12b to 14b, respectively, forming flow paths for the groundwater pumped up from the second to fourth hot well chambers 12b to 14b.

[0028] The first cold well pumping pipe 31a accommodates a first cold well s41a, and the first hot well pumping pipe 31b accommodates a first hot well pump 41b. The first cold well pump 41a is connected to a first pipe 51 that passes through the heat exchanger 1, and delivers groundwater in the first cold well pumping pipe 31a to the first pipe 51. Similarly, the first hot well pump 41b is connected to the first pipe 51, and delivers groundwater in the first hot well pumping pipe 31b to the first pipe 51. Therefore, when the first cold well pump 41a is driven while the first hot well pump 41b is stopped, the groundwater in the first cold well chamber 11a is delivered to the first hot well chamber 11b through the first pipe 51, the first hot well pump 41b, and the first hot well pumping pipe 31b. Similarly, when the first hot well pump 41b is driven while the first cold well pump 41a is stopped, the groundwater in the first hot well chamber 11b is pumped to the first cold well chamber 11a through the first piping 51, the first cold well pump 41a, and the first cold well pumping pipe 31a.

[0029] In this way, the first cold well pump 41a pumps groundwater from the first cold well chamber 11a and sends it to the first hot well chamber 11b through the heat exchange unit 1, and the first hot well pump 41b pumps groundwater from the first hot well chamber 11b and sends it to the first cold well chamber 11a through the heat exchange unit 1. Because the first cold well chamber 11a and the first hot well chamber 11b are connected to the first aquifer A1, water pumped from the first aquifer A1 using one of the cold well 10a and the hot well 10b can be returned to the first aquifer A1 using the other well.

[0030] The second cold well pump 42a is accommodated in the second cold well pumping pipe 32a, and the second hot well pump 42b is accommodated in the second hot well pumping pipe 32b. The second cold well pump 42a is connected to a second pipe 52 that passes through the heat exchanger 1, and delivers groundwater in the second cold well pumping pipe 32a to the second pipe 52. Similarly, the second hot well pump 42b is connected to the second pipe 52, and delivers groundwater in the second hot well pumping pipe 32b to the second pipe 52. Therefore, when the second cold well pump 42a is driven while the second hot well pump 42b is stopped, the groundwater in the second cold well chamber 12a is delivered to the second hot well chamber 12b through the second pipe 52, the second hot well pump 42b, and the second hot well pumping pipe 32b. Similarly, when the second hot well pump 42b is driven while the second cold well pump 42a is stopped, the groundwater in the second hot well chamber 12b is pumped to the second cold well chamber 12a through the second piping 52, the second cold well pump 42a, and the second cold well pumping pipe 32a.

[0031] In this way, the second cold well pump 42a pumps groundwater from the second cold well chamber 12a and sends it to the second hot well chamber 12b through the heat exchange unit 1, and the second hot well pump 42b pumps groundwater from the second hot well chamber 12b and sends it to the second cold well chamber 12a through the heat exchange unit 1. Because the second cold well chamber 12a and the second hot well chamber 12b are connected to the second aquifer A2, water pumped from the second aquifer A2 using one of the cold well 10a and the hot well 10b can be returned to the second aquifer A2 using the other well.

[0032] The first cold well chamber 11a and the second cold well chamber 12a are separated by a cold well water shielding layer 22a, and the first hot well chamber 11b and the second hot well chamber 12b are separated by a hot well water shielding layer 22b. Therefore, the groundwater in the first aquifer A1 and the groundwater in the second aquifer A2 do not mix. This prevents clogging caused by mixing of the groundwater in the first aquifer A1 and the groundwater in the second aquifer A2, and maintains the water flow performance of the cold well 10a and the hot well 10b.

[0033] The aquifer thermal storage system 100 further includes a third cold well pump 43a and a third hot well pump 43b. The third cold well pump 43a pumps groundwater from the third cold well chamber 13a and sends it to the third hot well chamber 13b through the heat exchanger 1, while the third hot well pump 43b pumps groundwater from the third hot well chamber 13b and sends it to the third cold well chamber 13a through the heat exchanger 1. Because the third cold well chamber 13a and the third hot well chamber 13b are connected to the third aquifer A3, water pumped from the third aquifer A3 using one of the cold well 10a and the hot well 10b can be returned to the third aquifer A3 using the other well.

[0034] The second cold well chamber 12a and the third cold well chamber 13a are separated by a cold well water shielding layer 23a, and the second hot well chamber 12b and the third hot well chamber 13b are separated by a hot well water shielding layer 23b. Therefore, the groundwater in the second aquifer A2 and the groundwater in the third aquifer A3 do not mix. This prevents clogging caused by mixing of the groundwater in the second aquifer A2 and the groundwater in the third aquifer A3, and maintains the water flow performance of the cold well 10a and the hot well 10b.

[0035] Furthermore, the groundwater in the first aquifer A1 and the groundwater in the third aquifer A3 do not mix, and therefore it is clear that clogging caused by the mixing of the groundwater in the first aquifer A1 and the groundwater in the third aquifer A3 can be prevented.

[0036] The aquifer thermal storage system 100 further includes a fourth cold well pump 44a and a fourth hot well pump 44b. The fourth cold well pump 44a pumps groundwater from the fourth cold well chamber 14a and sends it to the fourth hot well chamber 14b through the heat exchange unit 1, while the fourth hot well pump 44b pumps groundwater from the fourth hot well chamber 14b and sends it to the fourth cold well chamber 14a through the heat exchange unit 1. Because the fourth cold well chamber 14a and the fourth hot well chamber 14b are connected to the fourth aquifer A4, water pumped from the fourth aquifer A4 using one of the cold well 10a and the hot well 10b can be returned to the fourth aquifer A4 using the other well.

[0037] The third cold well chamber 13a and the fourth cold well chamber 14a are separated by a cold well water shielding layer 24a, and the third hot well chamber 13b and the fourth hot well chamber 14b are separated by a hot well water shielding layer 24b. Therefore, the groundwater in the third aquifer A3 and the groundwater in the fourth aquifer A4 do not mix. This prevents clogging caused by mixing of the groundwater in the third aquifer A3 and the groundwater in the fourth aquifer A4, and maintains the water flow performance of the cold well 10a and the hot well 10b.

[0038] Furthermore, the groundwater in the first aquifer A1 and the groundwater in the fourth aquifer A4 do not mix, which clearly prevents clogging caused by mixing of the groundwater in the first aquifer A1 and the groundwater in the fourth aquifer A4. Similarly, the groundwater in the second aquifer A2 and the groundwater in the fourth aquifer A4 do not mix, which clearly prevents clogging caused by mixing of the groundwater in the second aquifer A2 and the groundwater in the fourth aquifer A4.

[0039] The first to fourth cold well pumps 41a to 44a are provided shallower than the cold well water impermeable layer 21a. Therefore, the first to fourth cold well pumps 41a to 44a can be pulled up to the ground without passing through the cold well water impermeable layer 21a. Therefore, the first to fourth cold well pumps 41a to 44a can be easily replaced or repaired, and the maintainability of the aquifer thermal storage system 100 can be improved.

[0040] The first to fourth cold well pumps 41a to 44a are provided at positions that satisfy the required effective suction head of the first to fourth cold well pumps 41a to 44a, respectively, so that groundwater can be pumped up from the first to fourth cold well chambers 11a to 14a to the heat exchange unit 1.

[0041] Similarly, the first to fourth hot well pumps 41b to 44b are provided shallower than the hot well water impermeable layer 21b. Therefore, the first to fourth hot well pumps 41b to 44b can be pulled up to the ground without passing through the hot well water impermeable layer 21b. Therefore, the first to fourth hot well pumps 41b to 44b can be easily replaced or repaired, and the maintainability of the aquifer thermal storage system 100 can be improved.

[0042] The first to fourth hot well pumps 41b to 44b are provided at positions that satisfy the required effective suction head of the first to fourth hot well pumps 41b to 44b, respectively. Therefore, groundwater can be pumped up from the first to fourth hot well chambers 11b to 14b to the heat exchange section 1.

[0043] First to fourth cold well foreign matter removal layers 61a to 64a are provided in the first to fourth cold well chambers 11a to 14a, respectively. The first to fourth cold well foreign matter removal layers 61a to 64a remove foreign matter from groundwater flowing from the first to fourth aquifers A1 to A4 into the first to fourth cold well pumping pipes 31a to 34a. Therefore, groundwater from which foreign matter has been removed flows into the first to fourth cold well pumps 41a to 44a, the first to fourth piping 51 to 54, and the first to fourth hot well pumps 41b to 44b. This prevents clogging of the first to fourth cold well pumps 41a to 44a, the first to fourth piping 51 to 54, and the first to fourth hot well pumps 41b to 44b due to the inflow of foreign matter, thereby improving the durability of the aquifer thermal storage system 100.

[0044] Similarly, first to fourth hot well foreign matter removal layers 61b to 64b are provided in the first to fourth hot well chambers 11b to 14b, respectively. The first to fourth hot well foreign matter removal layers 61b to 64b remove foreign matter from the groundwater flowing from the first to fourth aquifers A1 to A4 into the first to fourth hot well pumping pipes 31b to 34b. Therefore, groundwater from which foreign matter has been removed flows into the first to fourth hot well pumps 41b to 44b, the first to fourth piping 51 to 54, and the first to fourth cold well pumps 41a to 44a. This prevents clogging of the first to fourth hot well pumps 41b to 44b, the first to fourth piping 51 to 54, and the first to fourth cold well pumps 41a to 44a due to the inflow of foreign matter, thereby improving the durability of the aquifer thermal storage system 100.

[0045] The first to fourth cold well foreign matter removal layers 61a to 64a and the first to fourth hot well foreign matter removal layers 61b to 64b are, for example, gravel filled in the first to fourth cold well chambers 11a to 14a and the first to fourth hot well chambers 11b to 14b.

[0046] The first cold well pumping pipe 31a includes a first cold well receptacle pipe 311a that accommodates the first cold well pump 41a and a first cold well insertion pipe 312a that extends from the first cold well receptacle pipe 311a and is inserted into the first cold well foreign matter removal layer 61a. The outer diameter of the first cold well insertion pipe 312a is smaller than that of the first cold well receptacle pipe 311a. Therefore, the gap between the outer surface of the first cold well insertion pipe 312a and the inner wall of the first cold well chamber 11a is wider than when the outer diameter of the first cold well insertion pipe 312a is equal to or greater than the outer diameter of the first cold well receptacle pipe 311a. This allows the first cold well foreign matter removal layer 61a to be thicker, more reliably removing foreign matter from groundwater flowing from the first aquifer A1 into the first cold well pumping pipe 31a.

[0047] The second cold well pumping pipe 32a includes a second cold well receptacle pipe 321a that accommodates the second cold well pump 42a and a second cold well insertion pipe section 322a that extends from the second cold well receptacle pipe 321a and is inserted into the second cold well foreign matter removal layer 62a. The outer diameter of the second cold well insertion pipe section 322a is smaller than that of the second cold well receptacle pipe 321a. Therefore, the gap between the outer surface of the second cold well insertion pipe section 322a and the inner wall of the second cold well chamber 12a is wider than when the outer diameter of the second cold well insertion pipe section 322a is equal to or greater than the outer diameter of the second cold well receptacle pipe 321a. This allows the second cold well foreign matter removal layer 62a to be thicker, more reliably removing foreign matter from groundwater flowing from the second aquifer A2 into the second cold well pumping pipe 32a.

[0048] The second cold well insertion pipe section 322a penetrates the first cold well foreign matter removal layer 61a. Therefore, the area occupied by the second cold well insertion pipe section 322a in the first cold well chamber 11a is smaller than when the outer diameter of the second cold well insertion pipe section 322a is equal to or greater than the outer diameter of the second cold well accommodation section pipe 321a. This allows the first cold well foreign matter removal layer 61a to be made thicker, more reliably removing foreign matter from groundwater flowing from the first aquifer A1 into the first cold well rise pipe 31a.

[0049] Like the second cold well pumping pipe 32a, the third cold well pumping pipe 33a includes a third cold well accommodation pipe 331a and a third cold well insertion pipe section 332a having an outer diameter smaller than that of the third cold well accommodation pipe 331a. The third cold well insertion pipe section 332a penetrates the first and second cold well foreign matter removal layers 61a, 62a. This allows the first and second cold well foreign matter removal layers 61a, 62a to be made thicker, thereby more reliably removing foreign matter from groundwater flowing from the first and second aquifers A1, A2 into the first and second cold well pumping pipes 31a, 32a.

[0050] Like the third cold well pumping pipe 33a, the fourth cold well pumping pipe 34a has a fourth cold well accommodation pipe 341a and a fourth cold well insertion pipe section 342a having an outer diameter smaller than that of the fourth cold well accommodation pipe 341a. The fourth cold well insertion pipe section 342a penetrates the first to third cold well foreign matter removal layers 61a to 63a. This allows the first to third cold well foreign matter removal layers 61a to 63a to be made thicker, thereby more reliably removing foreign matter from groundwater flowing from the first to third aquifers A1 to A3 into the first to third cold well pumping pipes 31a to 33a.

[0051] The first to fourth hot well pumping pipes 31b to 34b, like the first to fourth cold well pumping pipes 31a to 34a, respectively have first to fourth hot well receptacle pipes 311b to 341b and first to fourth hot well insertion pipe sections 312b to 342b. The structures of the first to fourth hot well receptacle pipes 311b to 341b and the first to fourth hot well insertion pipe sections 312b to 342b are substantially the same as the structures of the first to fourth cold well receptacle pipes 311a to 341a and the first to fourth cold well insertion pipe sections 312a to 342a, so detailed descriptions thereof will be omitted.

[0052] 1 and 3, the lower end opening (first opening) of the first cold well pumping pipe 31a is disposed closer to the central axis of the cold well 10a than the second to fourth cold well pumping pipes 32a to 34a in the first cold well chamber 11a. Therefore, the distance between the lower end opening of the first cold well pumping pipe 31a and the inner wall of the first cold well chamber 11a is approximately equal along the entire circumference of the first cold well pumping pipe 31a. Therefore, foreign matter in the groundwater flowing from the first aquifer A1 into the first cold well pumping pipe 31a can be removed evenly along the entire circumference of the first cold well pumping pipe 31a.

[0053] 1 and 4, the second cold well pumping pipe 32a is disposed so as to approach the central axis of the cold well 10a as it approaches the lower end opening (second opening) of the second cold well pumping pipe 32a. Therefore, the distance between the lower end opening of the second cold well pumping pipe 32a and the inner wall of the second cold well chamber 12a is approximately equal around the entire circumference of the second cold well pumping pipe 32a. Therefore, not only can foreign matter in the groundwater flowing from the first aquifer A1 into the first cold well pumping pipe 31a be removed evenly around the entire circumference of the first cold well pumping pipe 31a, but also foreign matter in the groundwater flowing from the second aquifer A2 into the second cold well pumping pipe 32a can be removed evenly around the entire circumference of the second cold well pumping pipe 32a.

[0054] In addition, in the first cold well chamber 11a, the second cold well pumping pipe 32a is located about the same distance from the central axis of the cold well 10a as the third and fourth cold well pumping pipes 33a, 34a, as shown in Figure 3, but in the second cold well chamber 12a, it is located closer to the central axis of the cold well 10a than the third and fourth cold well pumping pipes 33a, 34a, as shown in Figure 4.

[0055] 1 and 5, the third cold well pumping pipe 33a, like the second cold well pumping pipe 32a, is disposed so as to approach the central axis of the cold well 10a as it approaches the lower end opening (third opening) of the third cold well pumping pipe 33a. Therefore, foreign matter in the groundwater flowing from the third aquifer A3 into the third cold well pumping pipe 33a can be removed evenly around the entire circumference of the third cold well pumping pipe 33a.

[0056] Although not shown in the figures, the fourth cold well pumping pipe 34a, like the second and third cold well pumping pipes 32a and 33a, is arranged so as to approach the central axis of the cold well 10a as it approaches the lower end opening (fourth opening) of the fourth cold well pumping pipe 34a. Therefore, foreign matter in the groundwater flowing from the fourth aquifer A4 into the fourth cold well pumping pipe 34a can be removed evenly around the entire circumference of the third cold well pumping pipe 34a.

[0057] The arrangement of the lower end openings (1st to 4th) of the first to fourth hot well pumping pipes 31b to 34b is approximately the same as the arrangement of the lower end openings (1st to 4th) of the first to fourth cold well pumping pipes 31a to 34a, so detailed explanations of these will be omitted.

[0058] 1 and 3, the first cold well chamber 11a is provided with a first cold well spacer 71a that holds the first to fourth cold well pumping pipes 31a to 34a. Fig. 6(a) is a perspective view of the first cold well spacer 71a.

[0059] 3 and 6(a), the first cold well spacer 71a has an outer ring 710a facing the inner wall of the first cold well chamber 11a, and inner rings 711a, 712a, 713a, and 714a provided inside the outer ring 710a. The inner ring 711a is disposed approximately at the center of the outer ring 710a, and the first cold well pumping pipe 31a passes through the inner ring 711a. The inner rings 712a, 713a, and 714a are disposed around the inner ring 711a, and the second to fourth cold well pumping pipes 32a to 34a pass through the inner rings 712a to 714a, respectively. The inner rings 712a to 714a are joined to the outer ring 710a, and the inner ring 711a is connected to the inner rings 712a to 714a via plate-shaped connecting portions 715a to 717a.

[0060] Because the first cold well spacer 71a holds the first to fourth cold well pumping pipes 31a to 34a, displacement of the first to fourth cold well pumping pipes 31a to 34a in the first cold well chamber 11a can be prevented. Therefore, the lower end opening (first opening) of the first cold well pumping pipe 31a can be maintained near the central axis of the cold well 10a, and foreign matter in the groundwater flowing from the first aquifer A1 into the first cold well pumping pipe 31a can be removed more evenly around the entire circumference of the first cold well pumping pipe 31a.

[0061] In the first cold well spacer 71a, the area inside the outer ring 710a and outside the inner rings 711a, 712a, 713a, and 714a is hollow, allowing groundwater to flow through (FIG. 3 shows the hollow filled with the first cold well foreign matter removal layer 61a). Therefore, the first cold well spacer 71a does not obstruct the flow of groundwater in the first cold well chamber 11a.

[0062] 1 and 4, the second cold well chamber 12a is provided with a second cold well spacer 72a that holds the second to fourth cold well pumping pipes 32a to 34a. Fig. 6(b) is a perspective view of the second cold well spacer 72a.

[0063] As shown in Figures 4 and 6(b), the second cold well spacer 72a differs from the first cold well spacer 71a in that it does not have the inner ring 712a of the first cold well spacer 71a and that a plate-shaped connecting portion 715a extends between the outer peripheral surface of the inner ring 711a and the inner peripheral surface of the outer ring 710a. The second cold well pumping pipe 32a is inserted through the inner ring 711a of the second cold well spacer 72a. Furthermore, the second cold well spacer 72a does not obstruct the flow of groundwater in the second cold well chamber 12a.

[0064] Because the second cold well spacer 72a holds the second to fourth cold well pumping pipes 32a, displacement of the second to fourth cold well pumping pipes 32a to 34a in the second cold well chamber 12a can be prevented. Therefore, the lower end opening (first opening) of the second cold well pumping pipe 32a can be maintained near the central axis of the cold well 10a, and foreign matter in the groundwater flowing from the second aquifer A2 into the second cold well pumping pipe 32a can be removed more evenly around the entire circumference of the second cold well pumping pipe 32a.

[0065] 1 and 5, the third cold well chamber 13a is provided with a third cold well spacer 73a that holds the third and fourth cold well pumping pipes 33a and 34a. As shown in Fig. 1, the fourth cold well chamber 14a is provided with a fourth cold well spacer 74a that holds the fourth cold well pumping pipe 34a.

[0066] Although a perspective view of the third cold well spacer 73a is omitted, the third cold well spacer 73a differs from the first cold well spacer 71a in that it does not have the inner rings 712a and 713a of the first cold well spacer 71a, and the plate-shaped connecting portions 715a and 716a extend between the outer peripheral surface of the inner ring 711a and the inner peripheral surface of the outer ring 710a. The third cold well pumping pipe 33a is inserted through the inner ring 711a of the third cold well spacer 73a. Furthermore, the third cold well spacer 73a does not obstruct the flow of groundwater in the third cold well chamber 13a.

[0067] Although a perspective view of the fourth cold well spacer 74a is omitted, the fourth cold well spacer 73a differs from the first cold well spacer 71a in that it does not have the inner rings 712a-714a of the first cold well spacer 71a, and the plate-shaped connecting portions 715a-717a extend between the outer peripheral surface of the inner ring 711a and the inner peripheral surface of the outer ring 710a. The fourth cold well pumping pipe 34a is inserted through the inner ring 711a of the fourth cold well spacer 73a. Furthermore, the fourth cold well spacer 74a does not obstruct the flow of groundwater in the fourth cold well chamber 14a.

[0068] The first to fourth hot well chambers 11b to 14b are provided with first hot well spacers 71b to 74b. The structures of the first to fourth hot well spacers 71b to 74b are substantially the same as the structures of the first to fourth cold well spacers 71a to 74a, and therefore detailed description thereof will be omitted.

[0069] The first to fourth cold well spacers 71a to 74a and the first to fourth hot well spacers 71b to 74b are made of, for example, metal. The first to fourth cold well spacers 71a to 74a and the first to fourth hot well spacers 71b to 74b may also be made of resin.

[0070] In the aquifer thermal storage system 100, the drive of the first to fourth cold well pumps 41a to 44a can be controlled individually. Therefore, the flexibility of operation of the aquifer thermal storage system 100 can be increased compared to when one cold well pump is used to pump groundwater from the first to fourth aquifers A1 to A4 or when the drive of the first to fourth cold well pumps 41a to 44a cannot be controlled individually.

[0071] If the drive of the first to fourth cold well pumps 41a to 44a could not be controlled individually, stopping the first cold well pump 41a would also stop the second to fourth cold well pumps 42a to 44a. As a result, the entire aquifer thermal storage system 100 would shut down. Furthermore, if the minimum operable output of the first to fourth cold well pumps 41a to 44a is 30% of the maximum output, driving the first cold well pump 41a at 30% of the maximum output would also drive the second to fourth cold well pumps 42a to 44a at 30% of the maximum output. As a result, the total output of the first to fourth cold well pumps 41a to 44a would be 30% ({30% + 30% + 30% + 30%} / 4) of the maximum output of the first to fourth cold well pumps 41a to 44a as a whole.

[0072] In this embodiment, the drive of the first to fourth cold well pumps 41a to 44a can be controlled individually. For example, the first cold well pump 41a can be stopped while the second to fourth cold well pumps 42a to 44a are driven. This allows the first cold well pump 41a to be maintained while the aquifer thermal storage system 100 is running, thereby improving the availability of the aquifer thermal storage system 100. Furthermore, the second to fourth cold well pumps 42a to 44a can be stopped while the first cold well pump 41a is driven at 30% of its maximum output. In this case, the total output of the first to fourth cold well pumps 41a to 44a is 7.5% (30% + 0% + 0% + 0%) of the total maximum output of the first to fourth cold well pumps 41a to 44a. This allows for a wider output range for the first to fourth cold well pumps 41a to 44a.

[0073] In the aquifer thermal storage system 100, the drive of the first to fourth hot well pumps 41b to 44b can be controlled individually. Therefore, the aquifer thermal storage system 100 can be operated with greater flexibility than when one hot well pump is used to pump groundwater from the first to fourth aquifers A1 to A4 or when the drive of the first to fourth hot well pumps 41b to 44b cannot be controlled individually.

[0074] According to the above embodiment, the following advantageous effects are achieved.

[0075] In this embodiment, the first cold well chamber 11a and the second cold well chamber 12a are separated by a cold well water shielding layer 22a, and the first hot well chamber 11b and the second hot well chamber 12b are separated by a hot well water shielding layer 22b. The first cold well pump 41a and the first hot well pump 41b pump groundwater from the first cold well chamber 11a and the first hot well chamber 11b and deliver it to the first hot well chamber 11b and the first cold well chamber 11a through the heat exchanger 1. The second cold well pump 42a and the second hot well pump 42b pump groundwater from the second cold well chamber 12a and the second hot well chamber 12b and deliver it to the second hot well chamber 12b and the second cold well chamber 12a through the heat exchanger 1. Therefore, the groundwater in the first aquifer A1 and the groundwater in the second aquifer A2 do not mix. Therefore, clogging caused by mixing of the groundwater in the first aquifer A1 and the groundwater in the second aquifer A2 can be prevented, and the water flow performance of the cold well 10a and the hot well 10b can be maintained.

[0076] In this embodiment, the first and second cold well pumps 41a and 42a are installed shallower than the cold well water impermeable layer 21a and at positions that satisfy the required effective suction heads of the first and second cold well pumps 41a and 42a, respectively. The first and second hot well pumps 41b and 42b are installed shallower than the hot well water impermeable layer 21b and at positions that satisfy the required effective suction heads of the first and second hot well pumps 41b and 42b, respectively. Therefore, the first and second cold well pumps 41a and 42a can be raised to the ground without passing through the cold well water impermeable layer 21a. Furthermore, the first and second hot well pumps 41b and 42b can be raised to the ground without passing through the hot well water impermeable layer 21b. Therefore, the first and second cold well pumps 41a and 42a and the first and second hot well pumps 41b and 42b can be easily replaced or repaired, improving the maintainability of the aquifer thermal storage system 100. Furthermore, groundwater can be pumped up to the heat exchange section 1 from the first to fourth cold well chambers 11a to 14a and the first to fourth hot well chambers 11b to 14b.

[0077] In this embodiment, the aquifer thermal storage system 100 further includes a first cold well foreign matter removal layer 61a and a second cold well foreign matter removal layer 62a, which are provided in the first cold well chamber 11a and the second cold well chamber 12a, respectively, and which remove foreign matter from the groundwater pumped from the first aquifer A1 and the second aquifer A2, and a first hot well foreign matter removal layer 61b and a second hot well foreign matter removal layer 62b, which are provided in the first hot well chamber 11b and the second hot well chamber 12b, respectively, and which remove foreign matter from the groundwater pumped from the first aquifer A1 and the second aquifer A2. Therefore, the groundwater from which foreign matter has been removed flows into the first and second cold well pumps 41a and 42b, the first and fourth pipes 51 and 52, and the first and second hot well pumps 41b to 42b. Therefore, clogging of the first and second cold well pumps 41a, 42a, the first and second piping 51, 52, and the first and second hot well pumps 41b, 42b due to the inflow of foreign matter can be prevented, and the durability of the aquifer thermal storage system 100 can be improved.

[0078] In this embodiment, the first cold well pumping pipe 31a and the first hot well pumping pipe 31b have a first cold well accommodating pipe section 311a and a first hot well accommodating pipe section 311b that accommodate the first cold well pump 41a and the first hot well pump 41b, and a first cold well insertion pipe section 312a and a first hot well insertion pipe section 312b that extend from the first cold well accommodating pipe section 311a and the first hot well accommodating pipe section 311b and are inserted into the first cold well foreign matter removal layer 61a and the first hot well foreign matter removal layer 61b, and the outer diameters of the first cold well insertion pipe section 312a and the first hot well insertion pipe section 312b are smaller than the outer diameters of the first cold well accommodating pipe section 311a and the first hot well accommodating pipe section 311b, and the second cold well pumping pipe 32a The second hot well pumping pipe 32b has a second cold well accommodating pipe section 321a and a second hot well accommodating pipe section 321b that accommodate the second cold well pump 42a and the second hot well pump 42b, and a second cold well insertion pipe section 322a and a second warm well insertion pipe section 322b that extend from the second cold well accommodating pipe section 321a and the second hot well accommodating pipe section 321b, penetrate the first cold well foreign matter removal layer 61a and the first hot well foreign matter removal layer 61b, and are inserted into the second cold well foreign matter removal layer 62a and the second warm well foreign matter removal layer 62b, and the outer diameters of the second cold well insertion pipe section 322a and the second warm well insertion pipe section 322b are smaller than the outer diameters of the second cold well accommodating pipe section 321a and the second hot well accommodating pipe section 321b. Therefore, compared to when the outer diameters of the first cold well insertion pipe section 312a and the first hot well insertion pipe section 312b are equal to or greater than the outer diameters of the first cold well accommodating pipe section 311a and the first hot well accommodating pipe section 311b and the outer diameters of the second cold well insertion pipe section 322a and the second hot well insertion pipe section 322b are equal to or greater than the outer diameters of the second cold well accommodating pipe section 321a and the second hot well accommodating pipe section 321b, the occupied area of the first cold well insertion pipe section 312a and the second cold well insertion pipe section 322a in the first cold well chamber 11a is smaller, the occupied area of the first hot well insertion pipe section 312b and the second hot well insertion pipe section 322b in the first hot well chamber 11b is smaller, the occupied area of the second cold well insertion pipe section 322a in the second cold well chamber 12a is smaller, and the occupied area of the second hot well insertion pipe section 322b in the second hot well chamber 12b is smaller. Therefore, the first cold well foreign matter removal layer 61a, the first hot well foreign matter removal layer 61b, the second cold well foreign matter removal layer 62a and the second hot well foreign matter removal layer 62b can be made thicker, and foreign matter in the groundwater can be more reliably removed.

[0079] In this embodiment, the lower end openings of the first cold well pumping pipe 31a and the first hot well pumping pipe 31b are disposed closer to the central axis of the cold well 10a and the hot well 10b than the second cold well pumping pipe 32a and the second hot well pumping pipe 32b in the first cold well chamber 11a and the first hot well chamber 11b, and the second cold well pumping pipe 32a and the second hot well pumping pipe 32b are disposed so as to approach the central axis of the cold well 10a and the hot well 10b as they approach the bottom openings of the second cold well pumping pipe 32a and the second hot well pumping pipe 32b. Therefore, foreign matter in the groundwater can be removed evenly around the entire circumference of the first cold well pumping pipe 31a and the first hot well pumping pipe 31b, and foreign matter in the groundwater can be removed evenly around the entire circumference of the second cold well pumping pipe 32a and the second hot well pumping pipe 32b.

[0080] In this embodiment, the aquifer thermal storage system 100 further includes a first cold well spacer 71a and a first hot well spacer 71b provided in the first cold well chamber 11a and the first hot well chamber 11b to hold the first and second cold well pumping pipes 31a and 32a and the first and second hot well pumping pipes 31b and 32b, and a second cold well spacer 72a and a second hot well spacer 72b provided in the second cold well chamber 12a and the second hot well chamber 12b to hold the second cold well pumping pipe 32a and the second hot well pumping pipe 32b. Therefore, displacement of the first and second cold well pumping pipes 31a and 32a and the first and second hot well pumping pipes 31b and 32b in the first cold well chamber 11a and the first hot well chamber 11b can be prevented. Therefore, the lower end openings of the first and second cold well pumping pipes 31a, 32a and the lower end openings of the first and second hot well pumping pipes 31b, 32b can be maintained near the central axes of the cold well 10a and the hot well 10b, and foreign matter in the groundwater can be removed more evenly around the entire circumference of the first and second cold well pumping pipes 31a, 32a and the first and second hot well pumping pipes 31b, 32b.

[0081] Furthermore, in this embodiment, the operation of the first and second cold well pumps 41a, 42a and the first and second hot well pumps 41b, 42b can be controlled individually. Therefore, the first and second cold well pumps 41a, 42a and the first and second hot well pumps 41b, 42b can be maintained individually while the aquifer thermal storage system 100 is operating, thereby increasing the availability of the aquifer thermal storage system 100. Furthermore, the overall output range of the first and second cold well pumps 41a, 42a and the overall output range of the first and second hot / cold well pumps 41b, 42b can be made wider.

[0082] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0083] In the aquifer thermal storage system 100, groundwater pumped up from the first to fourth aquifers A1 to A4 is used for heat exchange with the heat medium flowing through one pipe 2, but the present invention is not limited to this. For example, four pipes 2 may be provided, and groundwater pumped up from the first to fourth aquifers A1 to A4 may be used for heat exchange with the heat medium flowing through each pipe 2.

[0084] In the aquifer thermal storage system 100, the cold well 10a and the hot well 10b cross four aquifers A, but the present invention is not limited to this. The cold well 10a and the hot well 10b may cross two, three, five or more aquifers A.

[0085] In the aquifer thermal storage system 100, the first cold well pumping pipe 31a is moved closer to the central axis of the cold well 10a as it goes downward so that the lower end opening (first opening) of the first cold well pumping pipe 31a is located on the central axis side of the cold well 10a. The present invention is not limited to this configuration, and the first cold well pumping pipe 31a may be arranged so that it extends straight down without being moved closer to the central axis side of the cold well 10a. Similarly, the first hot well pumping pipe 31b may be arranged so that it extends straight down without being moved closer to the central axis side of the hot well 10b.

[0086] In the aquifer thermal storage system 100, the second cold well pumping pipe 32a is arranged so as to approach the central axis of the cold well 10a as it approaches the lower end opening (second opening) of the second cold well pumping pipe 32a. The present invention is not limited to this configuration, and the second cold well pumping pipe 32a may be arranged so as to extend linearly downward without being close to the central axis of the cold well 10a. The second hot well pumping pipe 32b may also be arranged so as to extend linearly downward without being close to the central axis of the hot well 10b. The third and fourth cold well pumping pipes 33a, 34a and the third and fourth hot well pumping pipes 33b, 34b may also be arranged so as to extend linearly downward without being close to the central axes of the cold well 10a and the hot well 10b.

[0087] Fig. 7 is a perspective view of a first cold well spacer 271a according to a modified embodiment of the present invention. The first cold well spacer 271a is used when lowering the first to fourth cold well pumping pipes 31a to 34a in a straight line. Fig. 8 is a cross-sectional view showing the state in which the first cold well spacer 271a is used to hold the first to fourth cold well pumping pipes 31a to 34a.

[0088] 7 and 8, the first cold well spacer 271a has an outer ring 2710a facing the inner wall of the first cold well chamber 11a, and an inner ring 2711a provided inside the outer ring 2710a. The inner ring 2711a is formed in a substantially square shape, and the first to fourth cold well pumping pipes 31a to 34a pass through the inner ring 2711a. The inner ring 2711a is connected to the outer ring 2710a via plate-shaped connecting portions 2715a to 2718a.

[0089] In the first cold well spacer 271a, the area inside the outer ring 2710a and outside the inner ring 2711a is hollow, allowing groundwater to flow through (FIG. 8 shows the hollow filled with the first cold well foreign matter removal layer 61a). Therefore, the first cold well spacer 271a does not obstruct the flow of groundwater in the first cold well chamber 11a.

[0090] The first cold well spacer 271a is made of, for example, metal, but may also be made of resin.

[0091] Fig. 9 is a perspective view of a first cold well spacer 371a according to another modified example of the embodiment of the present invention. Like the first cold well spacer 271a, the first cold well spacer 371a is used when lowering the first to fourth cold well pumping pipes 31a to 34a in a straight line. Fig. 10 is a cross-sectional view showing the state in which the first cold well spacer 371a is used to hold the first to fourth cold well pumping pipes 31a to 34a.

[0092] 9 and 10, the first cold well spacer 371a has an outer ring 3710a facing the inner wall of the first cold well chamber 11a, and an inner ring 3711a provided inside the outer ring 3710a. The inner ring 3711a is formed in a substantially diamond shape, and the first to fourth cold well pumping pipes 31a to 34a pass through the inner ring 3711a. The inner ring 3711a is connected to the outer ring 3710a via plate-shaped connecting portions 3715a to 3718a.

[0093] In the first cold well spacer 371a, the area inside the outer ring 3710a and outside the inner ring 3711a is hollow, allowing groundwater to flow through (FIG. 10 shows the hollow filled with the first cold well foreign matter removal layer 61a). Therefore, the first cold well spacer 371a does not obstruct the flow of groundwater in the first cold well chamber 11a.

[0094] The first cold well spacer 371a is made of, for example, metal, but may also be made of resin.

[0095] Fig. 11 is a perspective view of a fourth cold well spacer 274a according to a modified embodiment of the present invention. The fourth cold well spacer 274a is used when lowering the fourth cold well rise pipe 34a in a straight line. Fig. 12 is a cross-sectional view showing the fourth cold well spacer 274a used to hold the fourth cold well rise pipe 34a.

[0096] 11 and 12, the fourth cold well spacer 274a has an outer ring 2740a and an inner ring 2741a provided inside the outer ring 2740a. The inner ring 2741a is disposed approximately at the center of the outer ring 2740a, and the fourth cold well pumping pipe 34a passes through the inner ring 2741a. The inner ring 2741a is connected to the outer ring 2740a via plate-shaped connecting portions 2745a to 2748a.

[0097] The outer diameter of the outer ring 2740a is smaller than the inner diameter of the cold well 10a, and the outer peripheral surface of the outer ring 2740a is spaced apart from the inner wall of the cold well 10a. A fourth cold well foreign matter removal layer 64a is filled between the outer peripheral surface of the outer ring 2740a and the inner wall of the cold well 10a.

[0098] In the fourth cold well spacer 274a, the area inside the outer ring 2740a and outside the inner ring 2741a is hollow, allowing groundwater to flow through (FIG. 12 shows the hollow filled with the fourth cold well foreign matter removal layer 64a). Therefore, the fourth cold well spacer 274a does not obstruct the flow of groundwater in the fourth cold well chamber 14a.

[0099] The fourth cold well spacer 274a is made of, for example, metal, but may also be made of resin.

[0100] Although not shown in the figures, when the first to fourth hot well pumping pipes 31b to 34b are lowered in a straight line, spacers having the same structure as the first cold well spacers 271a, 371a and the fourth cold well spacer 274a can be used instead of the first hot well spacer 71b and the fourth hot well spacer 74b provided in the first hot well chamber 11b and the fourth hot well chamber 14b. [Explanation of symbols]

[0101] 100···Aquifer thermal storage system 1...Heat exchange section 10a Cold well (first well) 10b: Hot well (second well) 11a...1st cold room (1st room) 11b...1st greenhouse room (1st room) 12a...2nd cold well room (2nd room) 12b...2nd greenhouse room (2nd room) 21a, 22a, 23a, 24a, 25a...Cold well impermeable layer (water impermeable layer) 21b, 22b, 23b, 24b, 25b... Warm well impermeable layer (impermeable layer) 31a···No. 1 Cold Well Riser Pipe (No. 1 Riser Pipe) 311a··First cold well containment pipe section (First containment pipe section) 312a··First cold well insertion pipe section (first insertion pipe section) 31b No. 1 Hot Well Riser Pipe (No. 1 Riser Pipe) 311b··First Hot Well Containment Pipe Section (First Containment Pipe Section) 312b··First hot well insertion pipe section (first insertion pipe section) 32a···No. 2 Cold Well Riser Pipe (No. 2 Riser Pipe) 321a··Second Cold Well Containment Pipe Section (Second Containment Pipe Section) 322a··Second cold well insertion pipe section (Second insertion pipe section) 32b No. 2 Cold Well Riser Pipe (No. 2 Riser Pipe) 321b··Second Hot Well Containment Pipe Section (Second Containment Pipe Section) 322b··Second hot well insertion pipe section (second insertion pipe section) 41a···No. 1 cold well pump (No. 1 pump) 41b···First hot well pump (first pump) 42a···No. 2 cold well pump (No. 2 pump) 42b No. 2 cold well pump (No. 2 pump) 61a...1st cold foreign matter removal layer (1st foreign matter removal layer) 61b...1st warm well foreign matter removal layer (1st foreign matter removal layer) 62a...Second cold foreign matter removal layer (second foreign matter removal layer) 62b...Second cold foreign matter removal layer (second foreign matter removal layer) 71a···First cold well spacer (first spacer) 71b···First hot well spacer (first spacer) 72a···Second cold well spacer (second spacer) 72b Second hot well spacer (second spacer)

Claims

1. An aquifer heat storage system that pumps up groundwater from a first aquifer and a second aquifer and returns it to the first aquifer and the second aquifer through a heat exchanger, a first well and a second well formed across the first aquifer and the second aquifer, and taking in groundwater from the first aquifer and the second aquifer; a water impermeable layer provided in the first well and the second well, forming a first chamber communicating with the first aquifer and a second chamber communicating with the second aquifer inside each of the first well and the second well; a first pump that pumps up groundwater from the first chamber of the first well and sends it to the first chamber of the second well through the heat exchanger; A second pump that pumps up groundwater from the second chamber of the first well and sends it to the second chamber of the second well through the heat exchanger. Aquifer thermal storage system.

2. The first pump and the second pump are respectively provided in a shallower portion of the first well than the water impermeable layer and at positions that satisfy the required effective suction heads of the first pump and the second pump.

10. The aquifer thermal storage system of claim 1.

3. the first well further includes a first foreign matter removal layer and a second foreign matter removal layer provided in the first chamber and the second chamber of the first well, respectively, for removing foreign matter from groundwater pumped from the first aquifer and the second aquifer; 10. The aquifer thermal storage system of claim 1.

4. a first lifting pipe forming a flow path for groundwater pumped up from the first chamber of the first well by the first pump; a second pump that forms a flow path for groundwater pumped up from the second chamber of the first well by the second pump; the first lifting pipe includes a first housing pipe portion that houses the first pump, and a first insertion pipe portion that extends from the first housing pipe portion and is inserted into the first foreign matter removal layer, and the outer diameter of the first insertion pipe portion is smaller than the outer diameter of the first housing pipe portion; the second lifting pipe includes a second housing pipe portion that houses the second pump, and a second insertion pipe portion that extends from the second housing pipe portion, penetrates the first foreign matter removal layer, and is inserted into the second foreign matter removal layer, and the outer diameter of the second insertion pipe portion is smaller than the outer diameter of the second housing pipe portion.

4. The aquifer thermal storage system of claim 3.

5. a first lift pipe having a first opening located in the first chamber of the first well and forming a flow path for groundwater pumped from the first chamber of the first well by the first pump; a second lift pipe having a second opening located in the second chamber of the first well and forming a flow path for groundwater pumped from the second chamber of the first well by the second pump; The first opening of the first riser pipe is disposed closer to the central axis of the first well than the second riser pipe in the first chamber of the first well; The second riser pipe is arranged so as to approach the central axis of the first well as it approaches the second opening.

4. The aquifer thermal storage system of claim 3.

6. a first spacer provided in the first chamber of the first well and holding the first riser pipe and the second riser pipe; A second spacer is provided in the second chamber of the first well and holds the second lifting pipe.

6. The aquifer thermal storage system of claim 5.

7. The first pump and the second pump can be controlled to be driven individually.

10. The aquifer thermal storage system of claim 1.

8. further comprising a third pump; The first well and the second well are formed across a third aquifer and take in groundwater from the third aquifer; the water impermeable layer further forms a third chamber in each of the first well and the second well, the third chamber communicating with the third aquifer; The third pump pumps up groundwater from the third chamber of the first well and sends it to the third chamber of the second well through the heat exchanger.

10. The aquifer thermal storage system of claim 1.

9. Further comprising a fourth pump; The first well and the second well are formed across a fourth aquifer and take in groundwater from the fourth aquifer; the water impermeable layer further forms a fourth chamber in each of the first well and the second well, the fourth chamber communicating with the fourth aquifer; The fourth pump pumps up groundwater from the fourth chamber of the first well and sends it to the fourth chamber of the second well through the heat exchanger.

10. The aquifer thermal storage system of claim 1.

10. An aquifer heat storage method using an aquifer heat storage system, pumping groundwater from a first aquifer and a second aquifer and returning the groundwater to the first aquifer and the second aquifer through a heat exchanger, respectively, The aquifer thermal storage system includes: a first well and a second well formed across the first aquifer and the second aquifer, and taking in groundwater from the first aquifer and the second aquifer; a water impermeable layer provided in the first well and the second well, forming a first chamber communicating with the first aquifer and a second chamber communicating with the second aquifer inside each of the first well and the second well; The aquifer heat storage method is Pumping groundwater from the first chamber of the first well and sending it through the heat exchanger to the first chamber of the second well; Pumping groundwater from the second chamber of the first well and sending it to the second chamber of the second well through the heat exchanger; Aquifer heat storage method.

Images