JP6432546B2 - Heat source water piping, underground heat-utilizing heat pump system, cleaning method and heat exchanging method inside the primary side heat exchanger - Google Patents

Description

  The present invention relates to a heat source water pipe that increases the heat exchange efficiency of a heat exchanger on the ground heat collection side of a heat pump of a heat pump system that uses geothermal heat, and an operation method thereof.

  The underground temperature is approximately constant at about the annual average temperature, and is substantially equal to the temperature of the well water. Therefore, it is lower than the outside air in the summer when the cooling is operated and higher than the outside air in the winter when the heating is operated. Therefore, geothermal heat is a suitable heat source for air conditioning and winter hot water supply.

  In general, a heat pump system using geothermal heat uses geothermal heat as a heat source of the heat pump and uses water or an antifreeze as a heat medium for the geothermal heat. Many of the underground heat exchangers used for collecting and radiating ground heat are constructed by arranging heat source water (circulating water) piping in boreholes, foundation piles, and the like. The heat source water pipe is connected to a heat exchanger (primary side heat exchanger) on the heat pump outdoor unit side, and the heat source water is circulated between the underground heat exchanger and the primary side heat exchanger of the heat pump by a circulation pump. At the same time, heat exchange is performed between the refrigerant of the heat pump and the heat source water in the primary side heat exchanger.

  When such a geothermal heat pump system is used for air conditioning, during cooling, the primary heat exchanger of the heat pump acts as a condenser that cools and liquefies the high-temperature and high-pressure refrigerant by the compressor using heat source water. . During heating, the primary heat exchanger of the heat pump acts as an evaporator that heats and vaporizes the refrigerant decompressed by the expansion valve with heat source water. Switching between cooling and heating is performed by switching the flow direction of the refrigerant in the heat pump using a four-way valve.

  The inventors tested a commercially available heat pump system using underground heat. As a result, the heat pump system using geothermal heat has confirmed an energy saving effect of 40% or more during cooling compared with an air heat source heat pump, while only obtaining an energy saving effect of about 10% to 20% during heating. . As a result of the investigation, the energy saving effect at the time of heating was smaller than the cooling, because it was a test in a relatively warm area, the difference between the heat source water temperature and the outside air temperature was not large, and in the primary heat exchanger part It was found that there was a difference in the heat exchange efficiency.

  Moreover, since the flow direction of the heat source water is unidirectional, in the long term, there is a concern that scale accumulates inside the primary side heat exchanger and heat exchange efficiency decreases.

  When the cause of the difference in heat exchange efficiency was further investigated, the refrigerant and heat source water flowed in opposite directions in the primary heat exchanger during cooling, whereas the refrigerant and heat source water flowed in opposite directions. It was found that the flow direction of the heat source water is the same as the flow direction of the heat source water, which reduces the heat exchange efficiency during heating, resulting in a difference in energy saving effect.

  This will be specifically described with reference to FIGS. FIG. 7 is a conceptual diagram showing the flow of refrigerant and heat source water during cooling in a conventional geothermal heat pump system, and FIG. 8 is a conceptual diagram showing the flow of refrigerant and heat source water during heating. The arrows in the figure indicate the direction in which the refrigerant and heat source water flow. In a conventional geothermal heat pump system, in the geothermal heat pump outdoor unit 8 (hereinafter referred to as the outdoor unit 8), the four-way valve 7 is switched between cooling and heating, and refrigerant discharged from the compressor 6 is discharged. The direction of circulation is reversed. On the other hand, in the heat source water pipe 1 having the underground heat exchange section 13, the heat source water always flows in one direction by the circulation pump 18 during cooling and heating. As shown in FIG. 7, since the refrigerant and heat source water flowed in opposite directions during cooling, high heat exchange efficiency was obtained. However, as shown in FIG. 8, during heating, the refrigerant and heat source water The direction of water flow was parallel, and the heat exchange efficiency was lower than that during cooling, resulting in a smaller energy saving effect.

  In patent document 1, in the air heat source heat pump, in both cases of cooling and heating, a technique has been proposed in which the air and refrigerant flow directions are always opposed to each other in the heat exchanger of the indoor unit and the outdoor unit. Yes. Specifically, in Patent Document 1, a switching valve and a bypass pipe for switching the flow direction of the refrigerant are provided at the inlet portion and the outlet portion of the heat exchangers in both the heat pump indoor unit and the outdoor unit, and the heat exchanger is heated. By reversing the flow direction of the refrigerant, the operation efficiency of the air conditioner is improved so that the flow direction of the air exchanged with the air exchanged in each heat exchanger is always the opposite flow.

  In Patent Document 2, as a method for removing the scale of the geothermal binary power generation preheater, a technique for removing the scale by reversing the flow of the heat source water with the refrigerant flow direction constant is proposed. Specifically, by changing the inflow / outflow direction of the heat source water using a three-way valve, gate valve, and bypass pipe, the heat exchanger is given a temperature change, and deposited in the heat exchanger pipe due to the difference in thermal expansion. It breaks and peels off the scale.

JP 7-91761 A JP 2010-38438 A

  When the flow directions of the heat source water and the refrigerant are in parallel flow, the heat exchange efficiency is lower than that in the case of counter flow, and therefore a mechanism for always having a counter flow in cooling and heating is required. In addition, when the heat source water always flows in one direction in the primary side heat exchanger, the scale easily accumulates inside, and the problem of a decrease in heat exchange efficiency due to the scale accumulation is also a problem.

  In the technology of Patent Document 1, a bypass circuit that reversely reverses the direction of the refrigerant is installed in the heat pump so that the direction of the refrigerant flowing in the heat exchanger is always the same in both the cooling and heating, and the refrigerant and the air are always opposed to each other. So that it is controlled. Therefore, there is a problem that the structure inside the heat pump becomes complicated, and maintenance labor and equipment cost increase. Further, in the present invention, water is used instead of air as a heat source, and the heat source water flows in one direction. Therefore, when the method of Patent Document 1 is used, the scale accumulates inside the heat exchanger. Is not solved.

  Regarding the scale removal accumulated in the heat exchanger, Patent Document 2 discloses that the heat source water flow is reversed. Here, the heat exchanger is also able to collect by peeling off the scale deposited on the heat transfer tubes of the heat exchanger while keeping the heat utilization operation without stopping the operation, but during the scale removal operation Since the refrigerant and the heat source water are in parallel flow, there is a problem that the heat collection efficiency is lowered. Further, the flow path leading to the scale removing device is closed during normal operation, and there is a problem that there is no means for removing scale in the heat source water during normal operation.

  The present invention has been made to solve the above-described problems. The refrigerant and the heat source water are made into a counter flow in a low-cost and easy-to-maintain state inside the heat exchanger, and further accumulated in the heat exchanger. It is an object of the present invention to provide a heat source water piping structure of an underground heat utilization heat pump system that can also remove the scale and the operation method thereof.

  The present invention has the following features in order to achieve the above object.

[1] A heat source water pipe connected to a primary heat exchanger of a heat pump outdoor unit,
An underground heat exchange section that exchanges heat between the heat source water and the ground,
A main pipe from the first connection X with the primary heat exchanger to the second connection Y with the primary heat exchanger via the underground heat exchange;
On the main pipe, a first branch pipe provided between a branch point A on the first connection part X side and a branch point B on the second connection part Y side;
On the main pipe, provided at a position farther from the primary heat exchanger than the branch point C provided between the first connection part X and the branch point A and the branch point B on the second connection part Y side. A second branch pipe provided between the branch point D and
A circulation pump which is provided at a position farther from the primary heat exchanger than the branch point A on the main pipe and discharges toward the branch point A;
A first switching means capable of switching the flow path on the first branch pipe side and the flow path on the branch point C side at the branch point A;
A heat source water pipe comprising, at a branch point D, second switching means capable of switching between a flow path on the second branch pipe side and a flow path on the branch point B side.

  [2] Using the first switching unit and the second switching unit, the flow direction of the heat source water in the primary side heat exchanger is switched, and the refrigerant of the heat pump and the flow of the heat source water that flow adjacently in the primary side heat exchanger. The heat source water pipe according to [1], wherein the direction is a counter flow both during heat collection and during heat release.

[3] In the main pipe, a branch point E provided at a position farther from the primary side heat exchanger than the circulation pump, and a branch point F provided at a position farther from the primary side heat exchanger than the branch point D. A third branch pipe provided therebetween;
A third switching means for switching the flow path on the third branch pipe side and the flow path on the branch point A side at the branch point E;
A fourth switching means for switching the flow path on the third branch pipe side and the flow path on the branch point D side at the branch point F;
Between the branch point A and the branch point E, there is a pipe connection part from the tank,
The heat source water pipe according to [1] or [2], comprising: a discharge port provided in a flow path from the branch point C to the branch point B via the primary side heat exchanger.

  [4] The heat source water pipe according to any one of [1] to [3], wherein a scale removing device is disposed between the branch point A and the circulation pump.

  [5] A geothermal heat pump system comprising the heat source water pipe according to any one of [1] to [4] and a heat pump.

[6] Using the first switching means and the second switching means, the direction of the heat source water flowing through the heat source water piping from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump is alternated. After switching to, supply the fluid stored in the tank between the branch point A and the branch point E from the tank,
A method for cleaning the inside of a primary heat exchanger using a geothermal heat pump system including the heat source water pipe and the heat pump according to [3] or [4], wherein the heat source water pushed out by the fluid is discharged from a discharge port.

[7] A method for cleaning the inside of a primary heat exchanger of a heat pump system using a geothermal heat including a heat source water pipe and a heat pump according to [4],
Using the first switching means and the second switching means, alternately switch the direction of the flow of the heat source water flowing through the heat source water pipe from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump, A cleaning method for the inside of the primary side heat exchanger, in which the scale inside the primary side heat exchanger is captured by a scale removing device installed between the branch point A and the circulation pump.

  [8] The cleaning method according to [6] or [7], wherein the cleaning is performed in a state where a flow path on the third branch pipe side is set and circulation to the underground heat exchange unit is stopped.

[9] Use the geothermal heat pump system according to [5],
It is connected to the primary side heat exchanger of the heat pump having the primary side heat exchanger and the secondary side heat exchanger, and flows to the heat source water pipe having the underground heat exchange part for exchanging heat with the ground inside the primary side heat exchanger. A heat exchange method between heat source water and a heat pump refrigerant,
The heat source water flowing in the primary side heat exchanger and the heat source water flowing adjacent to each other in the primary side heat exchanger by switching the direction of the heat source water flowing in the primary side heat exchanger by switching means provided in the heat source water piping during heat collection and heat dissipation Exchange method in which the flow of water is counterflowed both during heat collection and heat dissipation.

  According to the present invention, even when using an existing heat pump in which the refrigerant pipe switching means that can make the flow direction of the refrigerant in the heat exchanger the same during the cooling and heating is not provided in the heat pump, the cooling and heating At both times, the refrigerant and the heat source water can be made into a counter flow at a low cost inside the primary side heat exchanger, high heat exchange efficiency can be obtained, and the scale can be accumulated inside the heat exchanger. Can be suppressed. Furthermore, since the heat source water is circulated only in an extremely narrow range by the bypass circuit in the cleaning of the primary side heat exchanger, the heat source water can be kept clean without circulating the scale in the entire circulation system, The amount of heat source water used for cleaning can be reduced. And since the heat source water containing a scale can be discharged | emitted from an open valve by gravity of the washing water inside a tank, the scale in the heat exchanger 14 can be wash | cleaned easily.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the heat source water piping connected to the heat pump which concerns on embodiment of this invention, and a geothermal heat utilization heat pump system containing this. It is a conceptual diagram which shows the flow of the refrigerant | coolant at the time of air_conditioning | cooling of the geothermal heat utilization heat pump system which concerns on embodiment of this invention. It is a conceptual diagram which shows the flow of the refrigerant | coolant and heat source water at the time of the heating of the geothermal heat utilization heat pump system which concerns on embodiment of this invention. It is a conceptual diagram which shows the 1st washing | cleaning process (normal circulation) of the geothermal heat pump system which concerns on embodiment of this invention. It is a conceptual diagram which shows the 2nd washing | cleaning process (backwashing) of the geothermal heat pump system which concerns on embodiment of this invention. It is a conceptual diagram which shows the 3rd washing | cleaning process (scale discharge | emission) of the geothermal heat pump system which concerns on embodiment of this invention. It is a conceptual diagram which shows the flow of the refrigerant | coolant at the time of the cooling of the conventional heat pump system using geothermal heat, and heat source water. It is a conceptual diagram which shows the flow of the refrigerant | coolant at the time of the heating of the conventional heat pump system using geothermal heat, and heat source water.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic diagram showing a heat source water pipe connected to the heat pump according to Embodiment 1 of the present invention and a geothermal heat pump system including the heat source water pipe.

  Although the geothermal heat pump system 100 can be used for various applications such as air conditioning and hot water supply such as air conditioning, in the following description, the secondary side direct expansion type geothermal heat pump system 100 used for air conditioning is used. Explained as an example.

  The outdoor unit 8 (hereinafter referred to as the outdoor unit 8) of the geothermal heat pump 101 is provided with a compressor 6, a four-way valve 7 and a primary side heat exchanger 14 (hereinafter referred to as a heat exchanger 14). The outdoor unit 8 and the indoor unit (not shown) are connected by a refrigerant pipe 15 through which the refrigerant circulates.

  The four-way valve 7 reverses the direction of the refrigerant flowing through the refrigerant pipe 15 and the heat exchanger 14 during cooling and heating. In addition, although the heat exchanger (secondary side heat exchanger) is provided also about the indoor unit, description about the structure of an indoor unit is abbreviate | omitted.

  A refrigerant pipe 15 and a heat source water pipe system 102 are connected to the heat exchanger 14. In the heat exchanger 14, the flow paths through which the refrigerant and the heat source water flow are arranged adjacent to each other, and heat exchange is performed between them.

  The heat source water piping system 102 includes a main pipe 16, a ground heat exchanging section 13, a first branch pipe 19, a second branch pipe 20, a plurality of switching means 21, 22, 23, 24, a circulation pump 18 and a tank 30, and a strainer. (Not shown).

  One end of the main pipe 16 is connected to the first connection part X of the heat exchanger 14, and the other end is connected to the second connection part Y of the heat exchanger 14.

  The main pipe 16 is inserted and buried in a cavity extending in the vertical direction, such as a boring hole provided in the ground, with its tip folded back in a U shape. This part functions as the underground heat exchange part 13 which collects and dissipates the underground heat. In the underground heat exchange part 13, heat exchange is performed between the ground via the heat source water. In addition, you may comprise the underground heat exchange part 13 so that it may be inserted in the circular steel pipe which was embedded in the earth and the front-end | tip was obstruct | occluded.

  The main pipe 16 on the first connection portion X side with the heat exchanger 14 has a branch point C, a branch point A, and a branch point E from the first connection portion X side.

  The main pipe 16 on the second connection portion Y side with the heat exchanger 14 has a branch point B, a branch point D, and a branch point F from the second connection portion Y side.

  The branch point A and the branch point B are connected by a first branch pipe 19, the branch point C and the branch point D are connected by a second branch pipe 20, and the branch point E and the branch point F are connected by a third branch pipe 28. Connected with.

  A circulation pump 18 is provided between the branch point A and the branch point E from the first connection part X side on the main pipe 16. The circulation pump 18 is installed so as to send out the heat source water toward the branch point A.

  The tank 30 is installed at a position where the bottom is higher than the main pipe 16 and the heat exchanger 14, and has a connection part G to the tank 30 between the circulation pump 18 and the branch point E. The connection part G is provided on the upper surface side of the pipe, and an open / close valve (not shown) is provided between the tank 30 and the connection part G, and when the volume change due to the temperature difference of the heat source water is absorbed and the pipe leaks. The open / close valve is always open to supply the heat source water.

  As the first switching means 21 at the branch point A and as the second switching means 22 at the branch point D, a three-way valve is provided, and the heat source water sent from the circulation pump 18 is supplied to the first branch pipe 19 and the second branch. It sends to the heat exchanger 14 and the underground heat exchange part 13 via the flow path sent to the heat exchanger 14 and the underground heat exchange part 13 without passing through the pipe 20, and the first branch pipe 19 and the second branch pipe 20. The flow path can be switched.

  A three-way valve is provided as a third switching means 23 at the branch point E and a fourth switching means 24 at the branch point F, respectively, and the heat source water sent from the circulation pump 18 is sent to the underground heat exchanger 13. The path and the flow path that bypasses the underground heat exchange unit 13 can be switched via the third branch pipe 28.

  A scale removing device such as a strainer for removing dust and scale components in the pipe is not shown, but is provided between the circulation pump 18 and the branch point A.

  The discharge port 25 is provided in a range from the branch point C to the branch point B via the heat exchanger 14, but is provided between the first connection portion X and the branch point C as shown in FIG. Is more desirable. The discharge port 25 is normally closed.

  Next, FIG. 2 shows the heat source water of the heat source water piping system 102 connected to the outdoor unit 8 according to the embodiment of the present invention during cooling and heating, and the refrigerant flow of the geothermal heat pump system 100 including the heat source water. It demonstrates using FIG. 3, and the washing | cleaning process of the heat-source water piping system | strain 102 is demonstrated using FIG. 4 thru | or FIG. 2 to 6, the flow path on the closed side of the switching means is shown in black, and the flow path on the open side is shown in white. Moreover, the flow path in which the heat source water flows is indicated by a solid line, and the flow path in which the flow of the heat source water stops is indicated by a dotted line. In addition, although the flow path from the tank 30 to the main pipe 16 is always open, it is treated here as having no water flow during normal operation.

  FIG. 2 is a diagram showing the flow of heat source water and refrigerant during cooling of the geothermal heat pump system according to the embodiment of the present invention.

  During cooling, the refrigerant in the outdoor unit 8 is discharged from the compressor 6, and is guided to the refrigerant pipe connection N side of the heat exchanger 14 in the four-way valve 7, so that the inside of the heat exchanger 14 is indicated by arrows. It flows to the pipe connection part M side.

  The heat source water sets a flow path by switching means arranged in the heat source water piping system 102. The following settings are made during cooling. At the branch point A, the first switching means 21 closes the flow path on the first branch pipe 19 side and opens the flow path from the circulation pump 18 to the branch point C.

  Similarly, at the branch point D, the flow path on the second branch pipe 20 side is closed by the second switching means 22 and the flow path flowing from the second connection portion Y toward the underground heat exchange section 13 is opened.

  At the branch point E and the branch point F, the third switching unit 23 and the fourth switching unit 24 close the flow path on the third branch pipe 28 side.

  The heat source water is sent out from the circulation pump 18 toward the branch point A. Therefore, in the above setting, as shown in FIG. 2, the heat source water passes from the branch point A via the first connection part X, the second connection part Y, the branch point D, and the underground heat exchange part 13. Circulate.

  That is, the heat source water at the time of cooling flows from the first connection part X to the second connection part Y in the heat exchanger 14, and the refrigerant and the heat source water that flow adjacently face each other.

  FIG. 3 is a diagram showing the flow of heat source water and refrigerant during heating in the geothermal heat pump system according to the embodiment of the present invention.

  During heating, the refrigerant of the outdoor unit 8 is discharged from the compressor 6 and led to the refrigerant pipe connection part M side of the heat exchanger 14 via the indoor unit (not shown) in the four-way valve 7. The inside of the heat exchanger 14 flows toward the refrigerant pipe connection portion N side as indicated by an arrow.

  The heat source water sets a flow path by switching means arranged in the heat source water piping system 102. The following settings are made during heating. At the branch point A, the first switching means 21 closes the flow path on the branch point C side, and from the outlet side of the circulation pump 18 to the second connection portion Y via the first branch pipe 19 and the branch point B. Open the flow path.

  Similarly, the flow path on the branch point B side is closed by the second switching means 22, and flows from the first connection part X toward the underground heat exchange part 13 via the second branch pipe 20 and the branch point D. Open the flow path.

  Note that, at the branch point E and the branch point F, the third switching unit 23 and the fourth switching unit 24 keep the flow path of the third branch pipe 28 closed as in the case of cooling.

  The heat source water is sent from the circulation pump 18 toward the branch point A as in the case of cooling. Therefore, in the above setting, as shown in FIG. 3, the heat source water flows from the branch point A to the branch point B, the second connection part Y, the first connection part X, the branch point C, the branch point D, the ground. It circulates through the intermediate heat exchanger 13.

  That is, the heat source water at the time of heating flows from the second connection portion Y to the first connection portion X in the heat exchanger 14, and the refrigerant and the heat source water that flow adjacently face each other.

  As described above, since the first switching means 21 and the second switching means 22 are controlled in conjunction with each other, they may be configured by electromagnetic valves and may be configured to be controlled to be opened and closed by a computer all at once. However, these open / close controls are minor operations, and may be operated manually.

  In the above description, cooling and heating have been described as examples. Cooling represents heat dissipation in the heat exchanger 14, and heating is used as a term representing heat collection. Needless to say, in a heat pump outdoor unit that is sometimes in parallel flow, cooling and heating are interchanged.

  Next, with reference to FIGS. 4 to 6, the heat exchanger 14 and the flow path cleaning process of the geothermal heat pump according to the present embodiment will be described. At the time of cleaning, the heat source water flow is repeated forward and backward by switching means arranged in the heat source water piping system 102, the scale inside the heat exchanger 14 is peeled off, and cleaning is performed.

  First, the operation of the circulation pump 18 is stopped. Then, at the branch point E, the flow path on the ground heat exchanging unit 13 side of the third switching means 23 is closed, and the flow path on the third branch pipe 28 side is opened. At the same time, at the branch point F, the flow path on the ground heat exchange section 13 side of the fourth switching means 24 is closed and the flow path on the third branch pipe 28 side is opened. Thereby, circulation of the heat source water to the underground heat exchange part 13 side is interrupted.

  Then, the circulation pump 18 is operated, and as shown in FIGS. 4 and 5, the flow path setting during cooling and the flow path setting during heating are alternately repeated for a predetermined time, so that the inside of the heat exchanger 14 The direction of the heat source water is alternately switched between a direction flowing from the first connection portion X to the second connection point Y and a direction flowing from the second connection point Y to the first connection portion X. Thereby, the scale accumulated in the heat source water flow path in the heat exchanger 14 is peeled off.

  Thereafter, the circulation pump 18 is stopped and the discharge port 25 is opened. FIG. 6 shows a state where the flow path on the second branch pipe 20 side of the second switching means 22 is closed as a more desirable form, but if the above process is repeated for one cycle or more, FIG. You may perform after completion | finish of the process shown in FIG. As a result, the heat source water including the scale separated from the heat exchanger 14 is discharged from the discharge port 25 by the pressure of the heat source water in the tank 30.

  If the heat exchanger 14 is very dirty, the outlet 25 is closed again, and the main water 16 or the cleaning fluid 26 is newly replenished from the tank 30 to the main pipe 16, and the above FIG. The process shown in FIG. 5 may be repeated.

  Further, before the cleaning, the cleaning fluid 26 is introduced into the tank 30 and the discharge port 25 at the stage where the flow path on the side of the underground heat exchange section 13 of the third switching means 23 and the fourth switching means 24 is closed. The cleaning fluid 26 may be introduced into the main pipe 16 by partially discharging the heat source water in the heat source water piping system 102 in the range, and the discharge port 25 is opened to release the heat source water in the range. The heat source water in the water pipe 102 system is once discharged, and the discharge port 25 is closed again. Then, the cleaning fluid 26 is newly put in the tank 30 and the circulation pump 18 is operated to perform the cleaning operation. .

  An electromagnetic valve may be provided in the third switching unit 23, the fourth switching unit 24, and the discharge port 25, and the opening / closing operation thereof may be electrically controlled, but may be manual.

  The replenishment of the discharged heat source water may be performed from the tank 30 after the discharge port 25 is closed. However, the heat source water is supplied into the tank 30 with the discharge port 25 being opened, and a new heat source is supplied from the discharge port 25. If the discharge port 25 is closed at the stage where water comes out, all the heat source water including the remaining scale can be discharged and replenished with new heat source water.

  After replenishing the heat source water, the circulation pump 18 is operated. In this step, the air remaining in the heat source water piping system 102 escapes through the tank 30 because the connection portion G is provided on the upper surface side of the piping. In the above process, when the third switching unit 23 and the fourth switching unit 24 are operated in advance so that the flow path on the branch pipe 28 side is closed, the normal process is performed in parallel with the air venting process in the main pipe 16. Return to the operating state.

  In the above, the cleaning-only process for discharging the heat source water including the scale to the outside and exchanging it has been shown, but the scale inside the heat exchanger 14 can be removed in parallel with the cooling or heating operation. Specifically, the first switching means 21 and the second switching means 22 are alternately operated as shown in FIGS. 2 and 3 to alternately change the flow direction of the heat source water in the heat exchanger 14. The scale that peels in this process and circulates in the heat source water piping system 102 together with the heat source water is collected by a strainer provided between the circulation pump 18 and the branch point A. In the configuration of the present invention, the heat source water always flows in the same direction regardless of the flow path, so even if a strainer is provided on the main pipe 16 without using the bypass circuit, the strainer captures it. There is no risk that collected garbage or scale will be re-released.

  Thus, the heat source water piping system 102 connected to the heat pump according to the present embodiment includes the first branch pipe 19 and the second branch pipe 20, and passes through the first branch pipe 19 and the second branch pipe 20. The flow direction of the heat source water in the heat exchanger 14 can be switched by switching whether to flow the heat source water.

  Thereby, the flow direction of the heat source water in the heat exchanger 14 is switched according to switching of the flow direction of the refrigerant in the refrigerant pipe 15 between the cooling time and the heating time. The refrigerant and the heat source water in the heat exchanger 14 can be made to counter flow, and the heat exchange efficiency can be improved.

  Moreover, since the heat source water piping system 102 connected to the heat pump according to the present embodiment is provided with a structure for switching the flow direction of the heat source water in the heat exchanger 14, the flow direction of the refrigerant in the outdoor unit 8. Even if the heat pump is not provided with a switching valve that switches the refrigerant and the heat source water to the opposite flow in the heat exchanger 14, high heat exchange efficiency can be obtained both during cooling and during heating.

  Further, means for switching the flow direction of the heat source water in the heat exchanger 14 (the first branch pipe 19, the second branch pipe 20, the first switch) to the heat source water pipe system 102 connected to the heat pump according to the present embodiment. Since the means 21 and the second switching means 22) are provided with a simple configuration, it is possible to reduce the equipment cost and obtain the same effect as compared to providing a switching valve on the outdoor unit 8 side.

  Further, in the present embodiment, the position of the bypass circuit by the third branch pipe 28, the tank 30, and the discharge port 25 are appropriately arranged, and further provided in the vicinity of the heat exchanger 14, thereby reducing the amount of heat source water used for cleaning. And the scale in the heat exchanger 14 can be easily cleaned.

  The present invention is not limited to the embodiment as described above, and various design changes can be made by a person skilled in the art.

  For example, in the present embodiment, the first switching unit 21 and the second switching unit 22 are provided at the branch point A and the branch point D, respectively, but a switching unit is further installed at the branch point B and the branch point C. Further, the switching means is not limited to a three-way valve.

  In addition, by providing a scale remover, such as a strainer, that removes dirt and scale components in the pipe between the circulation pump 18 and the branch point A, this section is always set regardless of the flow path. Since the heat source water flows in the same direction, even if a strainer is provided on the main pipe 16 without using a bypass circuit, there is no possibility that dust and scale collected by the strainer will be released again.

8 Heat pump outdoor unit using geothermal heat 13 Ground heat exchanger 14 Heat exchanger (primary heat exchanger)
DESCRIPTION OF SYMBOLS 15 Refrigerant piping 16 Main piping 18 Circulation pump 19 1st branch piping 20 2nd branch piping 21 1st switching means 22 2nd switching means 23 3rd switching means 24 4th switching means 25 Outlet 26 Cleaning fluid 28 3rd branch Piping 30 Tank 100 Geothermal heat pump system 101 Geothermal heat pump 102 Heat source water piping system

Claims (12)

A heat source water pipe connected to the primary heat exchanger of the heat pump outdoor unit,
An underground heat exchange section that exchanges heat between the heat source water and the ground,
A main pipe from the first connection X with the primary heat exchanger to the second connection Y with the primary heat exchanger via the underground heat exchange;
On the main pipe, a first branch pipe provided between a branch point A on the first connection part X side and a branch point B on the second connection part Y side;
On the main pipe, provided at a position farther from the primary heat exchanger than the branch point C provided between the first connection part X and the branch point A and the branch point B on the second connection part Y side. A second branch pipe provided between the branch point D and
A circulation pump which is provided at a position farther from the primary heat exchanger than the branch point A on the main pipe and discharges toward the branch point A;
A first switching means capable of switching the flow path on the first branch pipe side and the flow path on the branch point C side at the branch point A;
A second switching means capable of switching between the flow path on the second branch pipe side and the flow path on the branch point B side at the branch point D;
In the main piping, it is provided between a branch point E provided at a position farther from the primary side heat exchanger than the circulation pump and a branch point F provided at a position farther from the primary side heat exchanger than the branch point D. A third branch pipe,
A third switching means for switching the flow path on the third branch pipe side and the flow path on the branch point A side at the branch point E;
A fourth switching means for switching the flow path on the third branch pipe side and the flow path on the branch point D side at the branch point F;
Between the branch point A and the branch point E, there is a pipe connection part from the tank,
A heat source water pipe comprising: a discharge port provided in a flow path from the branch point C to the branch point B through the primary side heat exchanger.   Using the first switching means and the second switching means, the flow direction of the heat source water in the primary side heat exchanger is switched, and the flow direction of the heat pump refrigerant and the heat source water flowing adjacently in the primary side heat exchanger is changed, The heat source water pipe according to claim 1, wherein the heat source water pipe is used as a counter flow in both heat collection and heat radiation.   The heat source water pipe according to claim 1 or 2, wherein a scale removing device is disposed between the branch point A and the circulation pump. A heat pump system using geothermal heat, comprising the heat source water pipe according to any one of claims 1 to 3 and a heat pump. A method for cleaning the inside of a primary heat exchanger of a ground heat heat pump system comprising the heat source water pipe according to any one of claims 1 to 3 and a heat pump,
Using the first switching means and the second switching means, the direction of the flow of the heat source water flowing through the heat source water pipe from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump was alternately switched. rear,
Supply the fluid stored in the tank between the branch point A and the branch point E from the tank,
A method for cleaning the inside of a primary heat exchanger using a geothermal heat pump system that discharges heat source water pushed out by the fluid from a discharge port. A method for cleaning the inside of the primary heat exchanger of a heat pump system using a geothermal heat equipped with a heat source water pipe and a heat pump,
The heat source water pipe is a heat source water pipe connected to the primary heat exchanger of the heat pump outdoor unit,
An underground heat exchange section that exchanges heat between the heat source water and the ground,
A main pipe from the first connection X with the primary heat exchanger to the second connection Y with the primary heat exchanger via the underground heat exchange;
On the main pipe, a first branch pipe provided between a branch point A on the first connection part X side and a branch point B on the second connection part Y side;
On the main pipe, provided at a position farther from the primary heat exchanger than the branch point C provided between the first connection part X and the branch point A and the branch point B on the second connection part Y side. A second branch pipe provided between the branch point D and
A circulation pump which is provided at a position farther from the primary heat exchanger than the branch point A on the main pipe and discharges toward the branch point A;
A first switching means capable of switching the flow path on the first branch pipe side and the flow path on the branch point C side at the branch point A;
A second switching means capable of switching between the flow path on the second branch pipe side and the flow path on the branch point B side at the branch point D ;
A heat source water pipe with a scale removing device between the branch point A and the circulation pump ,
Using the first switching means and the second switching means, the direction of the flow of the heat source water flowing through the heat source water pipe from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump was alternately switched. rear,
Supply the fluid stored in the tank between the branch point A and the branch point E from the tank,
A method for cleaning the inside of a primary heat exchanger using a geothermal heat pump system that discharges heat source water pushed out by the fluid from a discharge port. The heat source water pipe uses the first switching means and the second switching means to switch the flow direction of the heat source water in the primary side heat exchanger, and the heat pump refrigerant and the heat source water flowing adjacently in the primary side heat exchanger. 7. The method for cleaning the inside of a primary heat exchanger using a geothermal heat pump system according to claim 6 , wherein the heat source water pipe is a counter flow in both the heat collecting and heat radiating directions. A method for cleaning the inside of the primary heat exchanger of the heat pump system using geothermal heat comprising the heat source water pipe and the heat pump according to claim 3 ,
Using the first switching means and the second switching means, alternately switch the direction of the flow of the heat source water flowing through the heat source water pipe from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump,
A cleaning method for the inside of the primary side heat exchanger, in which the scale inside the primary side heat exchanger is captured by a scale removing device installed between the branch point A and the circulation pump. A method for cleaning the inside of the primary heat exchanger of a heat pump system using a geothermal heat equipped with a heat source water pipe and a heat pump,
The heat source water pipe is a heat source water pipe connected to the primary heat exchanger of the heat pump outdoor unit,
An underground heat exchange section that exchanges heat between the heat source water and the ground,
A main pipe from the first connection X with the primary heat exchanger to the second connection Y with the primary heat exchanger via the underground heat exchange;
On the main pipe, a first branch pipe provided between a branch point A on the first connection part X side and a branch point B on the second connection part Y side;
On the main pipe, provided at a position farther from the primary heat exchanger than the branch point C provided between the first connection part X and the branch point A and the branch point B on the second connection part Y side. A second branch pipe provided between the branch point D and
A circulation pump which is provided at a position farther from the primary heat exchanger than the branch point A on the main pipe and discharges toward the branch point A;
A first switching means capable of switching the flow path on the first branch pipe side and the flow path on the branch point C side at the branch point A;
A second switching means capable of switching between the flow path on the second branch pipe side and the flow path on the branch point B side at the branch point D ;
A heat source water pipe with a scale removing device between the branch point A and the circulation pump ,
Using the first switching means and the second switching means, alternately switch the direction of the flow of the heat source water flowing through the heat source water pipe from the first connection portion X to the second connection portion Y in the primary heat exchanger of the heat pump,
A cleaning method for the inside of the primary side heat exchanger, in which the scale inside the primary side heat exchanger is captured by a scale removing device installed between the branch point A and the circulation pump. The heat source water pipe uses the first switching means and the second switching means to switch the flow direction of the heat source water in the primary side heat exchanger, and the heat pump refrigerant and the heat source water flowing adjacently in the primary side heat exchanger. The cleaning method for the inside of the primary heat exchanger of the geothermal heat pump system according to claim 9 , wherein the heat source water pipe is a counter flow in both the heat collecting and the heat radiation. The washing | cleaning method in any one of Claims 5 thru | or 10 which wash | cleans in the state which set the flow path by the side of 3rd branch piping, and stopped the circulation to an underground heat exchange part. Using the geothermal heat pump system according to claim 4 ,
It is connected to the primary side heat exchanger of the heat pump having the primary side heat exchanger and the secondary side heat exchanger, and flows to the heat source water pipe having the underground heat exchange part for exchanging heat with the ground inside the primary side heat exchanger. A heat exchange method between heat source water and a heat pump refrigerant,
The heat source water flowing in the primary side heat exchanger and the heat source water flowing adjacent to each other in the primary side heat exchanger by switching the direction of the heat source water flowing in the primary side heat exchanger by switching means provided in the heat source water piping during heat collection and heat dissipation Exchange method in which the flow of water is counterflowed both during heat collection and heat dissipation.

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