JPWO2016098263A1 - Heat exchanger and heat pump type hot water generator using the same - Google Patents

Abstract

Without reducing the flow velocity of the water flowing inside, the heat pump type that can effectively suppress the precipitation of scale and can simplify the maintenance workability and the heat pump type equipped with the heat exchanger An object is to provide a hot water generator. In order to achieve this object, in a heat exchanger that includes a first pipe through which a heat medium flows and a second pipe through which water that exchanges heat with the heat medium flows, a heat medium that flows through the first pipe; The water flowing in the second pipe forms a counter flow, and the first pipe heat-exchanges between the heat medium flowing upstream from the first pipe and the heat medium flowing into the first pipe. A heat exchanger is provided.

Description

  The present invention relates to, for example, a heat exchanger that generates hot water using heat of condensation of a refrigerant in a heat pump hot water supply device, and a heat pump hot water generation device using the heat exchanger.

  2. Description of the Related Art Conventionally, a heat pump hot water generator such as a heat pump hot water supplier uses a refrigeration circuit that circulates a refrigerant as a heat pump unit to generate hot water supplied to hot water. In this case, in the heat exchanger constituting the refrigeration circuit, a first pipe through which a refrigerant such as carbon dioxide circulates and a second pipe through which water (hot water) to be heated circulates are arranged so that heat can be exchanged. ing. Generally, the refrigerant flowing through the first pipe and the water flowing through the second pipe are arranged so as to face each other in consideration of thermal efficiency. Therefore, the hot water immediately after exchanging heat with the high-temperature refrigerant is sent out from the outlet of the second pipe.

  At this time, the water flowing in the second pipe is often tap water or groundwater, and contains mineral components such as calcium and magnesium. The mineral component mainly deposits calcium carbonate or the like as a so-called scale on the outlet side where the temperature is high in the second pipe.

  If scale accumulates on the inner wall of the second pipe serving as a heat transfer surface, the heat exchange efficiency with the first pipe is reduced. When the heat exchange efficiency is lowered, it becomes difficult to obtain a target hot water temperature, and energy is consumed more than necessary in order to set the hot water temperature as the target temperature.

  Moreover, if the scale deposited on the inner wall of the second pipe is left unattended, the scale may block the second pipe. Therefore, in areas where water with a large amount of scale component is used, the problem becomes significant due to scale deposition, and frequent maintenance work is forced.

  Therefore, as a technique for suppressing the scale deposition, there is a heat pump water heater disclosed in Patent Document 1. The heat pump water heater of Patent Document 1 includes a heat pump circuit including at least a compressor, a radiator, an expansion valve, and an evaporator, and the radiator is a refrigerant water heat exchanger that radiates heat to water to obtain hot water. In addition, the inside of the water outlet pipe connected to the water side outlet is configured to expand in accordance with the direction of water flow. Adopting this configuration eliminates the part of the water-side flow path of the heat pump water heater where the water flow at the high-temperature outlet, which tends to adhere to the scale, becomes stagnation, and is reliable for adhesion of the scale, etc. I was trying to improve.

JP-A-2005-77062

  As described above, in the configuration of Patent Document 1, since the water outlet pipe is configured to expand in accordance with the water flow direction, there is a problem in that the flow rate of water is decreased and the hot water supply performance is decreased. Moreover, the said structure does not suppress precipitation of a scale, but only delays time until piping is completely obstruct | occluded with a scale. Furthermore, since the size of the water pipe itself is large, this configuration has a problem of increasing the size of heat exchange and increasing costs.

    Therefore, from the market, it is possible to effectively suppress the precipitation of scale without reducing the flow rate of the water flowing inside, and the heat exchanger and the heat exchange that can simplify the maintenance workability. There has been a demand for the development of a heat pump type hot water generator equipped with a vessel.

  Therefore, the inventors of the present invention, as a result of earnest research, have a heat exchanger that can effectively suppress the precipitation of scale without adversely affecting the hot water supply performance, and a heat pump type hot water generator including the heat exchanger. It came to offer.

  That is, the heat exchanger according to the present invention includes a first pipe through which a heat medium flows and a second pipe through which water that exchanges heat with the heat medium flows. The heat medium flowing through the second pipe and the water flowing through the second pipe form a counterflow, and the first pipe flows into the first pipe and the heat medium flowing upstream from the first pipe. And an internal heat exchanger for exchanging heat with the heated medium.

  In the heat exchanger according to the present invention, when the internal heat exchanger has a length of the first pipe of a portion used for heat exchange with the second pipe as 100%, the heat medium of the first pipe It is preferable to exchange heat between the heat medium flowing in any position within the range of 4% to 50% from the inlet end and the heat medium flowing upstream from the first pipe.

  The heat exchanger according to the present invention is a double pipe in which a heat conductive inner pipe constituting the first pipe is arranged in an outer pipe constituting the second pipe, and the internal heat exchanger It is preferable that the pipe is connected to the inner pipe drawn out to the outside through the outer pipe.

  Further, the heat exchanger is more preferably one in which a plurality of inner pipes constituting the first pipe are arranged in an outer pipe constituting the second pipe.

  Furthermore, as for the said heat exchanger, it is more preferable that 1st piping itself consists of double piping.

  Further, in the heat exchanger according to the present invention, the first pipe and the second pipe are in contact with the outer walls, the heat medium flowing inside the first pipe, and the water flowing inside the second pipe. It is also preferable that they are arranged so that heat exchange is possible.

  The heat pump type hot water generating device according to the present invention includes a compressor, a use side heat exchanger, a pressure reducing device, a heat source side heat exchanger, a refrigerant circuit in which a refrigerant is enclosed, and hot water generating water. A heat medium circuit that circulates, wherein the use-side heat exchanger is the heat exchanger according to any one of claims 1 to 3, and the heat flowing into the first pipe. The medium is a refrigerant discharged from the compressor of the refrigerant circuit, and the water flowing in the second pipe is water for generating hot water of the heat medium circuit.

  In the heat pump hot water generator according to the present invention, the refrigerant is preferably a carbon dioxide refrigerant.

  According to the present invention, in the heat exchanger in which the heat medium flowing through the first pipe and the water flowing through the second pipe form a counter flow, the first pipe is a heat medium flowing upstream from the first pipe. And an internal heat exchanger that exchanges heat with the heat medium that has flowed into the first pipe, thereby suppressing a decrease in the heat exchange efficiency of the entire heat exchanger and the heat of the first pipe that is the highest temperature. It becomes possible to lower the temperature in the vicinity of the medium inlet. Therefore, it is possible to avoid the disadvantage that the water in the vicinity of the water outlet of the second pipe that performs heat exchange with the vicinity of the heat medium inlet of the first pipe is locally high in temperature, and the scale is formed in the vicinity of the water outlet of the second pipe. It is possible to effectively suppress the precipitation. Therefore, the maintenance work required by the precipitation of scale can be simplified.

  Further, in the present invention, the heat medium flowing upstream from the first pipe in the internal heat exchanger and flowing into the first pipe without expanding the diameter near the water outlet of the second pipe as in the prior art. By exchanging heat with the heat medium, it is possible to lower the temperature in the vicinity of the heat medium inlet of the first pipe, so there is no need to reduce the flow rate of the water flowing in the second pipe. Therefore, the present invention can effectively suppress the precipitation of scale without adversely affecting the hot water supply performance.

  A heat pump type hot water generating device according to the present invention includes a compressor, a use side heat exchanger, a pressure reducing device, a heat source side heat exchanger, a refrigerant circuit in which a refrigerant is enclosed, and hot water generation A heat medium circuit through which water is circulated, wherein the heat exchanger according to the present invention is adopted as the use-side heat exchanger, the refrigerant of the refrigerant circuit is caused to flow in the first pipe, and the second pipe It is possible to lower the temperature in the vicinity of the refrigerant inlet of the first pipe, which is the highest temperature, by flowing warm water generating water for the heat medium circuit through the first pipe. Therefore, it is possible to avoid the inconvenience that the hot water generating water in the vicinity of the water outlet of the second pipe that performs heat exchange with the vicinity of the refrigerant inlet of the first pipe is locally high in the vicinity of the water outlet of the second pipe. It is possible to effectively suppress the precipitation of scale. Therefore, also for the heat pump hot water generator, the maintenance work required by the deposition of scale can be simplified.

It is a schematic block diagram of the heat pump type hot-water supply apparatus as embodiment of this invention. It is a schematic block diagram of the utilization side heat exchanger of FIG. It is a figure which shows the performance of the heat exchanger of the whole utilization side heat exchanger at the time of arrange | positioning an internal heat exchanger in each position. It is a figure which shows the temperature change of the refrigerant | coolant and water supply water at the time of providing an internal heat exchanger in a refrigerant | coolant inlet side edge part (comparative example). It is a figure which shows the temperature change of a refrigerant | coolant and water supply water when an internal heat exchanger is provided in the position of 8% from the refrigerant | coolant inlet side edge part (Example). It is a figure which shows the temperature change of a refrigerant | coolant and water supply water at the time of providing an internal heat exchanger in the position of 50% from the refrigerant | coolant inlet side edge part (Example).

  Hereinafter, as an embodiment of the heat exchanger of the present invention, a heat pump type hot water supply apparatus H as an example of a heat pump type hot water generating apparatus provided with the heat exchanger according to the present invention will be described as an example. FIG. 1 shows a schematic configuration diagram of a heat pump type hot water supply apparatus H as the present embodiment. The heat pump type hot water supply apparatus H according to the present embodiment of the present invention includes a heat pump unit 1 including a refrigerant circuit 10 and a tank unit 2 including a heat medium circuit 20.

  The refrigerant circuit 10 constituting the heat pump unit 1 includes a compressor 11, a use side heat exchanger 12, an expansion valve 13 as a pressure reducing device, and a heat source side heat exchanger 14. Thus, a known refrigerant circuit is configured. The heat source side heat exchanger 14 employs an air cooling method in which heat is taken from air ventilated by a blower 15 installed in the vicinity to evaporate the refrigerant. A predetermined amount of refrigerant is sealed in the refrigerant circuit 10. The refrigerant is preferably a carbon dioxide refrigerant that is one of natural refrigerants. However, the refrigerant adopted in the heat pump hot water supply apparatus in the present invention is not limited to the carbon dioxide refrigerant, and any refrigerant can be used.

  The heat medium circuit 20 constituting the tank unit 2 is configured by pipe-connecting a hot water storage tank 21, a circulation pump 22, and the above-described use side heat exchanger 12 in an annular manner. The hot water storage tank 21 is supplied with hot water supply water as hot water generation water such as tap water and groundwater according to consumption of hot water, and a predetermined amount of hot water supply water is stored. The hot water supplied from the hot water storage tank 21 is circulated in the heat medium circuit 20 by the operation of the circulation pump 22.

  The use-side heat exchanger 12 that constitutes the refrigerant circuit 10 and the heat medium circuit 20 described above is constituted by the heat exchanger according to the present invention. Hereinafter, the use side heat exchanger 12 according to the present embodiment will be described in detail with reference to FIG.

  The use-side heat exchanger 12 according to the present embodiment includes a first pipe 12a through which a heat medium, that is, a high-temperature high-temperature refrigerant in the refrigerant circuit 10 flows, and water that performs heat exchange with the heat medium therein. That is, the second pipe 12b through which the hot water supply water in the heat medium circuit 20 flows is provided. In the present embodiment, specifically, the use-side heat exchanger 12 is composed of a double pipe in which a heat conductive inner pipe constituting the first pipe 12a is arranged in an outer pipe constituting the second pipe 12b. It is preferable. When the use side heat exchanger 12 is configured by a double pipe, the refrigerant flows through the inner pipe constituting the first pipe 12a, and hot water supply water is provided between the inner wall of the second pipe 12b and the outer wall of the first pipe 12a. Circulate. In this case, the first pipe 12a as the inner pipe through which the refrigerant flows is disposed in the second pipe 12b as the outer pipe through which the hot water supply water flows. A plurality may be provided. Furthermore, although the use side heat exchanger 12 is constituted by a double pipe, it may be constituted by a multiple pipe in which the first pipe 12a disposed in the second pipe 12b itself is a double pipe. This is because when the first pipe 12a itself is a double pipe, it may be performed for the purpose of detecting leakage of the refrigerant. Moreover, although the utilization side heat exchanger 12 in this Embodiment has mentioned and demonstrated as an example the case where it comprised by multiple piping containing double piping, it is not limited to this, For example, 1st piping And the second pipe adopts a configuration in which the outer walls are in contact with each other and brazed, and the heat medium flowing inside the first pipe and the water flowing inside the second pipe are arranged so as to be able to exchange heat. Also good. When the outer walls are arranged in contact with each other, the first pipe through which the heat medium flows is constituted by a thin pipe branched into a plurality, and heat exchange is performed by winding the thin pipe constituting the first pipe around the second pipe. It may be possible. At this time, when pulling out to the internal heat exchanger, the narrow pipes are once joined together to exchange heat with the heat medium flowing upstream from the first pipe, and then the first pipe is again connected to the narrow pipe. You may branch to and wind around the second pipe.

  And the said utilization side heat exchanger 12 is comprised so that the refrigerant | coolant which flows through the inside of the 1st piping 12a, and the hot water supply water which flows through the 2nd piping 12b may form a counterflow. That is, the high-temperature refrigerant that flows through the inlet side of the first pipe 12a exchanges heat with hot water that is relatively heated and flows through the outlet side of the second pipe 12b, and the low-temperature refrigerant that flows through the inlet side of the second pipe 12b. The hot water supply water is arranged so as to exchange heat with the refrigerant of a relatively low temperature flowing on the outlet side of the first pipe 12a. For example, the refrigerant flowing through the first pipe 12a flows into the first pipe 12a at 100 ° C., and flows out of the first pipe 12a in a state of being lowered to about 10 ° C. by performing heat exchange with hot water. And the hot water supply water which flows through the 2nd piping 12b flows in into the 2nd piping 12b at 5 degreeC, and flows out out of the 2nd piping 12b in the state heated to about 65 degreeC by exchanging heat with a high temperature refrigerant | coolant. .

  Moreover, it is preferable that the 2nd piping 12b which comprises the heat exchanger 12 which concerns on this invention has a uniform pipe diameter at least from the inlet side to the outlet side of the hot water supply water.

  In the heat exchanger 12 according to the present invention, the first pipe 12a in which the refrigerant flows inside heats the high-temperature refrigerant that flows upstream from the first pipe 12a and the refrigerant that flows into the first pipe 12a. An internal heat exchanger 16 to be replaced is provided. The use side heat exchanger 12 in the present embodiment is configured by a double pipe in which the refrigerant flows into the first pipe 12a that is the inner pipe and the hot water supply water flows into the second pipe 12b that is the outer pipe. Therefore, the internal heat exchanger 16 is pipe-connected to the first pipe 12a that is an inner pipe drawn through the second pipe 12b that is an outer pipe.

  Specifically, the refrigerant that has flowed into the first pipe 12a that exchanges heat with the high-temperature refrigerant that flows upstream from the first pipe 12a has the length of the first pipe 12a that is used for heat exchange with the second pipe 12b. It is preferable that the refrigerant flow in any position within the range of 4% to 50% from the refrigerant (heat medium) inlet side end of the first pipe 12a when the ratio is 100%. That is, the internal heat exchanger 16 is 4% to 50% from the refrigerant inlet side end of the first pipe 12a when the length of the first pipe 12a in the portion used for heat exchange with the second pipe 12b is 100%. It is preferable to be connected to any position in the range of%.

  At this time, considering the thermal efficiency, the refrigerant flowing into the first pipe 12a that exchanges heat with the high-temperature refrigerant before flowing into the first pipe 12a in the internal heat exchanger 16 is used for heat exchange with the second pipe 12b. When the length of the portion of the first pipe 12a to be used is 100%, the refrigerant flows through any position in the range of 4% to 40% from the refrigerant (heat medium) inlet side end of the first pipe 12a. Is preferred. If it is less than 4%, the position where the internal heat exchange is performed is too close to the refrigerant outlet side of the first pipe 12a, and it is difficult to suppress the occurrence of a locally high temperature, and the second pipe 12b through which hot water supply water flows This is because the effect of suppressing the scale deposited on the inner wall is difficult to obtain. On the other hand, when it exceeds 40%, the heat exchange efficiency is less than 90% compared to the case where the internal heat exchanger 16 is not provided.

  On the other hand, in consideration of production efficiency, the refrigerant flowing into the first pipe 12a that exchanges heat with the high-temperature refrigerant before flowing into the first pipe 12a in the internal heat exchanger 16 is used for heat exchange with the second pipe 12b. When the length of the portion of the first pipe 12a to be used is 100%, the refrigerant flowing through a position of 50% from the refrigerant (heat medium) inlet side end of the first pipe 12a, that is, the intermediate position of the first pipe 12a A flowing refrigerant is preferred. In general, a heat exchanger is configured by joining a plurality of pipes. When one first pipe 12a is formed by joining two members, an internal heat exchanger 16 is connected to the joint portion. This is because production efficiency is improved.

  With the above configuration, when the compressor 11 is operated, the high-temperature and high-pressure gas refrigerant compressed by the compressor 11 flows into the internal heat exchanger 16 and is already in the first pipe of the use side heat exchanger 12. Heat is exchanged with the refrigerant flowing into 12a. At this time, in the internal heat exchanger 16, it is preferable to dissipate 10 deg to 25 deg of the high-temperature refrigerant that will flow into the first pipe 12a of the use side heat exchanger 12 from now on. The refrigerant that has passed through the internal heat exchanger 16 flows into the first pipe 12a of the use side heat exchanger 12 and exchanges heat with the hot water for water flowing through the second pipe 12b of the use side heat exchanger 12. Heat is dissipated.

  In the usage-side heat exchanger 12, the refrigerant flowing from the inlet of the first pipe 12 a is once radiated by the internal heat exchanger 16, so that the refrigerant temperature is the value before flowing into the internal heat exchanger 16. Lower than the refrigerant temperature. The refrigerant that has flowed in from the inlet side of the first pipe 12a, then drawn out to the outside, passed through the internal heat exchanger 16, and then flowed into the first pipe 12a again has a high temperature before flowing into the first pipe 12a. By exchanging heat with the refrigerant, in a heated state again, the refrigerant returns to the refrigerant downstream side in the first pipe 12a from the position drawn to the internal heat exchanger 16. Therefore, the temperature distribution of the refrigerant flowing in the first pipe 12a of the use side heat exchanger 12 does not tend to decrease uniformly from the inlet side to the outlet side, and the internal heat exchanger 16 is not provided. In comparison, the refrigerant temperature at the inlet side is low and has a peak again at the location where the refrigerant flows after passing through the internal heat exchanger 16. In the present embodiment, since the carbon dioxide refrigerant is used as the refrigerant, the refrigerant is compressed to the supercritical pressure in the compressor 11 and is not condensed in the use-side heat exchanger 12, and the supercritical pressure is maintained. .

  Thereafter, the refrigerant that has exited from the use side heat exchanger 12 is decompressed by the expansion valve 13, and in the process, the carbon dioxide refrigerant enters a gas-liquid mixed state and flows into the heat source side heat exchanger 14. The refrigerant that has flowed into the heat source side heat exchanger 14 exchanges heat with the outside air ventilated by the blower 15, evaporates, and draws up heat from the outside air. The refrigerant evaporated in the heat source side heat exchanger 14 is repeatedly sucked into the compressor 11, compressed and discharged again to the internal heat exchanger 16.

  On the other hand, in the heat medium circuit 20, when the circulation pump 22 is operated, the hot water supply water in the hot water storage tank 21 sent from the circulation pump 22 flows into the second pipe 12 b of the use side heat exchanger 12. The hot water supply water that has flowed into the second pipe 12b of the use side heat exchanger 12 exchanges heat with the high-temperature refrigerant in the refrigerant circuit 10 that flows in the counterflow in the first pipe 12a. After being heated in the use side heat exchanger 12, the hot water supply water returns to the hot water storage tank 21. Then, the circulation is repeated until the temperature of the hot water supply water in the hot water storage tank 21 reaches a predetermined temperature.

  At this time, as described above, the refrigerant once radiated by the internal heat exchanger 16 flows into the first pipe 12a from the refrigerant inlet side, and then heated through the internal heat exchanger 16. The refrigerant that has flowed into the first pipe 12a again flows. Therefore, the hot water supply water flowing in the second pipe 12b in a heat exchange oppositely to the refrigerant flowing in the first pipe 12a is gradually heated from the inlet side to rise in temperature, and the internal heat exchanger 16 is The temperature rises sharply at a position where heat exchange with the refrigerant flowing through the first pipe 12a immediately after being heated is performed. After that, heat is exchanged in a counter flow with the refrigerant flowing in from the inlet side of the first pipe 12a, so that the temperature rises slowly toward the outlet of the second pipe 12b. Since the refrigerant flowing in from the inlet side of the first pipe 12a is a refrigerant once radiated through the internal heat exchanger 16, the vicinity of the inlet side of the first pipe 12a becomes locally high in temperature. Is suppressed.

  As described above, in the present invention, in the internal heat exchanger 16, the high-temperature refrigerant flowing into the first pipe 12a of the use side heat exchanger 12 is heat-exchanged with the refrigerant after flowing into the first pipe 12a. Thus, it is possible to lower the temperature near the refrigerant inlet of the first pipe 12a, which is the highest temperature, while suppressing a decrease in the heat exchange efficiency of the entire use side heat exchanger 12. Therefore, the hot water supply water flowing in the vicinity of the outlet side of the second pipe 12b that exchanges heat with the refrigerant is prevented from being heated to a high temperature of 90 ° C. or more even when locally, It is possible to effectively suppress the disadvantage that mainly contained calcium carbonate or the like is deposited on the inner wall of the second pipe 12b as a scale. Therefore, the maintenance work required by the precipitation of scale can be simplified.

  In the present invention, the refrigerant flowing upstream from the first pipe 12a in the internal heat exchanger 16 without expanding the diameter near the water outlet of the second pipe as in the prior art, and in the first pipe 12a By exchanging heat with the refrigerant that has flown into the first pipe 12a, the temperature near the refrigerant inlet of the first pipe 12a can be lowered. Therefore, it is not necessary to reduce the flow rate of hot water flowing through the second pipe 12b. Therefore, the present invention can effectively suppress the precipitation of scale without adversely affecting the hot water supply performance.

  Next, the Example using the heat pump type hot-water supply apparatus H based on this invention is described. In this example, the heat pump type hot water supply apparatus H according to the present embodiment described above was used. In the present embodiment, the arrangement position of the internal heat exchanger 16 with respect to the first pipe 12a of the use side heat exchanger 12 is provided at a different position. Specifically, when the arrangement position of the internal heat exchanger 16 is 100% of the length of the first pipe 12a in the portion used for heat exchange with the second pipe 12b, the refrigerant inlet of the first pipe 12a. It provided in the position of 5%, 8%, 13%, 25%, 38%, 50% from the side edge part.

Comparative example

  As a comparative example, when the length of the first pipe 12a in the portion where the internal heat exchanger 16 is used for heat exchange with the second pipe 12b is 100%, 0% from the refrigerant inlet side end of the first pipe 12a. The internal heat exchanger 16 was provided at the position of the refrigerant inlet side of the first pipe 12a.

  Below, with reference to FIG. 3, the performance of the heat exchanger of the utilization side heat exchanger 12 whole at the time of arrange | positioning the internal heat exchanger 16 in each position is described. The performance as the use-side heat exchanger 12 in which the internal heat exchanger 16 is disposed at each position is as follows. When the heat exchange efficiency when the internal heat exchanger 16 is not provided is 100%, the internal heat exchanger 16 Is provided at a position from the inlet side to the outlet side of the first pipe 12a, the performance as a heat exchanger decreases. FIG. 4 shows a temperature change from the inlet side to the outlet side of hot water supply water and refrigerant when the internal heat exchanger 16 is provided at the refrigerant inlet side end of the first pipe 12a.

  As shown in FIG. 4, when the internal heat exchanger 16 is provided at the refrigerant inlet side end of the first pipe 12a, the refrigerant flows into the first pipe 12a of the use side heat exchanger 12 at 92 ° C. The temperature gradually decreases toward the outlet and then flows out at 15 ° C. And the hot water supply water flows into the second pipe 12b of the use side heat exchanger 12 at 10 ° C, gradually increases in temperature toward the outlet, and flows out at 65 ° C. Therefore, since the temperature in the vicinity of the inlet of the first pipe 12a rises to 92 ° C., a local high temperature state occurs, and the outlet of the second pipe 12b that exchanges heat with the refrigerant flowing in the vicinity of the inlet of the first pipe 12a. The hot-water supply water flowing in the vicinity becomes locally high in temperature, and the mineral components contained in the hot-water supply water become scales and easily deposit on the inner wall of the second pipe 12b.

  On the other hand, as shown in FIG. 3, when the performance as a heat exchanger when the internal heat exchanger 15 is not provided is 100%, the internal heat exchanger 16 is moved from the end of the refrigerant inlet side of the first pipe 12a to 8%. %, The performance as a heat exchanger was 99.6%. Similarly, when the internal heat exchanger 16 is provided at a position 13% from the refrigerant inlet side end of the first pipe 12a, when it is provided at a position 99.2% and 25%, 96.9% and 38%. When provided at the position of 91.3%, it was 77.5% when provided at the position of 50%.

  As an example, FIG. 5 shows a temperature change from the inlet side to the outlet side of hot water and refrigerant when the internal heat exchanger 16 is provided at a position 8% from the refrigerant inlet side end of the first pipe 12a. FIG. 6 shows the case where it is provided at a position of 50%.

  As shown in FIG. 5, when the internal heat exchanger 16 is provided at a position 8% from the refrigerant inlet side end of the first pipe 12 a, the first pipe 12 a of the use side heat exchanger 12 has a refrigerant Flows in at 78 ° C. and then decreases to 65 ° C. by heat exchange with hot water, and then again reaches 80 ° C. by heat exchange with the high-temperature refrigerant before flowing into the first pipe 12a in the internal heat exchanger 16. To rise. Thereafter, it gradually decreases toward the outlet and flows out at 18 ° C. Then, the hot water supply water flows into the second pipe b of the use side heat exchanger 12 at 12 ° C., and gradually rises in temperature, at a position 8% from the refrigerant inlet side end of the first pipe 12a, that is, The temperature rapidly rises to 61 ° C. at a position of 8% from the end of the second pipe 12b at the hot water outlet side. Thereafter, the temperature rises slowly toward the outlet and flows out at 65 ° C. Therefore, the first pipe 12a can heat the hot water supply water flowing through the second pipe 12b to 65 ° C. without raising the temperature up to 80 ° C. at the maximum.

  Accordingly, in the present embodiment corresponding to the present invention from FIG. 5, since the local high temperature state does not occur in the first pipe 12a through which the refrigerant flows, the second exchanges heat with the refrigerant flowing through the first pipe 12a. It can be seen that the hot water supply water flowing through the pipe 12b can effectively suppress the inconvenience of locally high temperature. Therefore, as shown in the said FIG. 5, according to this invention, it understands that the mineral component contained in the hot water supply water can effectively suppress the inconvenience which deposits on the inner wall of the said 2nd piping 12b as a scale. it can.

  On the other hand, as shown in FIG. 6, when the internal heat exchanger 16 is provided at a position 50% from the refrigerant inlet side end of the first pipe 12a, the first pipe 12a of the use side heat exchanger 12 has Then, after the refrigerant flows in at 81 ° C. and then decreases to 52 ° C. by heat exchange with hot water, 61 again by heat exchange with the high-temperature refrigerant before flowing into the first pipe 12a in the internal heat exchanger 16 Rise to ℃. Thereafter, it gradually decreases toward the outlet and flows out at 22 ° C. Then, the hot water supply water flows into the second pipe b of the use side heat exchanger 12 at 11 ° C. and gradually rises in temperature, and is located at a position of 50% from the refrigerant inlet side end of the first pipe 12a, that is, The temperature rises steeply to 51 ° C. at a position 50% from the end of the second pipe 12b at the hot water outlet side. Thereafter, the temperature rises slowly toward the outlet and flows out at 65 ° C. Therefore, also in this case, the first pipe 12a can heat the hot water supply water flowing through the second pipe 12b to 65 ° C. without raising the temperature to 80 ° C. at the maximum.

  However, when the length of the first pipe 12a in the portion where the internal heat exchanger 16 is used for heat exchange with the second pipe 12b is 100%, the position of the first pipe 12a is 50% from the end on the refrigerant inlet side. Since the heat exchange efficiency is reduced to 78.0% as compared with the case where the internal heat exchanger 16 is not provided, the heat exchange efficiency is considered as described above. The arrangement position of the internal heat exchanger 16 is 4% to 40% from the end portion on the refrigerant inlet side when the length of the first pipe 12a in the portion used for heat exchange with the second pipe 12b is 100%. It can be seen that the range is preferred. On the other hand, considering that one first pipe 12a is constituted by joining two members, it is advantageous in terms of production efficiency to join the internal heat exchanger 16 between the members constituting the first pipe 12a. It is. As described above, scale deposition can be effectively suppressed even when the internal heat exchanger 16 is provided at a position 50% from the refrigerant inlet side end of the first pipe 12a. It can also be said that it is advantageous to provide the internal heat exchanger 16 at a position 50% from the end on the refrigerant inlet side.

  In the present embodiment, a heat pump type hot water supply apparatus is cited as an example of an apparatus that employs the heat exchanger according to the present invention. However, the heat pump type hot water supply apparatus supplies hot water by heat exchange between water and a heat medium. It was only mentioned as an example of the heat pump type hot water generating device to be generated. Therefore, the heat pump type hot water generating device according to the present invention is not limited to the hot water supply device described above, a heat pump type heating device that generates hot water by heat exchange between water and a heat medium and uses it for heating, and these It includes the concept of a heat pump hot water supply / heating device that is also used.

  The heat exchanger according to the present invention can efficiently suppress the precipitation of scale without expanding the diameter of the second pipe through which water flows. Therefore, it is particularly useful for utilization of a heat pump type hot water supply apparatus and the like that are required to be reduced in size, improved in hot water supply performance, and improved in workability.

H Heat pump type hot water supply device 1 Heat pump unit 2 Tank unit 10 Refrigerant circuit 11 Compressor 12 Use side heat exchanger (heat exchanger)
12a First pipe (inner pipe)
12b Second pipe (outer pipe)
13 Pressure reducing device (expansion valve)
14 Heat Source Side Heat Exchanger 15 Blower 16 Internal Heat Exchanger 20 Heat Transfer Circuit 21 Hot Water Storage Tank 22 Circulation Pump

[0003]
It came to provide the heat pump which can suppress precipitation of a scale effectively, and the heat pump type hot water production | generation apparatus provided with the said heat exchanger.
[0011]
That is, the heat exchanger according to the present invention includes a first pipe through which a heat medium flows, and a second pipe through which water that exchanges heat with the heat medium flows. The heat pipe flowing through the first pipe and the water flowing through the second pipe are double pipes in which the heat conductive inner pipe constituting the first pipe is disposed in the outer pipe constituting the first pipe. In addition to forming a counter flow, the first pipe flows into the first pipe and a heat medium that is higher in temperature than the heat medium flowing into the first pipe and flows upstream from the first pipe. An internal heat exchanger for exchanging heat with the heat medium is provided, and the internal heat exchanger is connected to an inner pipe drawn out to the outside through the outer pipe.
[0012]
In the heat exchanger according to the present invention, when the internal heat exchanger has a length of the first pipe of a portion used for heat exchange with the second pipe as 100%, the heat medium of the first pipe It is preferable to exchange heat between the heat medium flowing in any position within the range of 4% to 50% from the inlet end and the heat medium flowing upstream from the first pipe.
[0013]
[0014]
Further, the heat exchanger is more preferably one in which a plurality of inner pipes constituting the first pipe are arranged in an outer pipe constituting the second pipe.
[0015]
Furthermore, as for the said heat exchanger, it is more preferable that 1st piping itself consists of double piping.
[0016]
[0017]
The heat pump type hot water generating device according to the present invention includes a compressor, a use side heat exchanger, a pressure reducing device, a heat source side heat exchanger, a refrigerant circuit in which a refrigerant is enclosed, and hot water generating water. The utilization side heat exchanger is a heat exchanger according to claim 1 or claim 2, comprising a circulating heat medium circuit.

Claims (8)

A heat exchanger comprising a first pipe through which a heat medium flows and a second pipe through which water that exchanges heat with the heat medium flows.
The heat medium flowing through the first pipe and the water flowing through the second pipe form a counter flow,
The first pipe is provided with an internal heat exchanger for exchanging heat between the heat medium flowing upstream from the first pipe and the heat medium flowing into the first pipe.   The internal heat exchanger is 4% to 50% from the heat medium inlet side end of the first pipe when the length of the first pipe of the portion used for heat exchange with the second pipe is 100%. The heat exchanger according to claim 1, wherein heat exchange between the heat medium flowing in any position of the range and the heat medium flowing upstream from the first pipe is performed. The outer pipe constituting the second pipe is composed of a double pipe provided with the heat conductive inner pipe constituting the first pipe,
The heat exchanger according to claim 1 or 2, wherein the internal heat exchanger is connected by piping to an inner pipe that passes through the outer pipe and is drawn to the outside.   The heat exchanger according to claim 3, wherein a plurality of inner pipes constituting the first pipe are arranged in an outer pipe constituting the second pipe.   The heat exchanger according to claim 3 or 4, wherein the first pipe itself is a double pipe.   The first pipe and the second pipe are arranged such that the outer walls are in contact with each other and the heat medium flowing inside the first pipe and the water flowing inside the second pipe can be exchanged with each other. Or the heat exchanger of Claim 2. A heat pump type comprising a compressor, a use side heat exchanger, a pressure reducing device, a heat source side heat exchanger, a refrigerant circuit in which a refrigerant is enclosed, and a heat medium circuit through which hot water generation water flows. A hot water generator,
The usage-side heat exchanger is the heat exchanger according to any one of claims 1 to 6, wherein the heat medium flowing in the first pipe is discharged from the compressor of the refrigerant circuit. The heat pump type hot water generating apparatus, wherein the water that is a refrigerant and flows into the second pipe is hot water generating water for the heat medium circuit.   The heat pump hot water generator according to claim 7, wherein the refrigerant is a carbon dioxide refrigerant.

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