JP6212698B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply device provided with a scale suppressing means.

  Conventionally, as this type of hot water supply apparatus, there is one that performs hot water supply using high-temperature hot water stored in a hot water tank (see, for example, Patent Document 1).

  FIG. 9 shows a conventional hot water supply apparatus described in FIG. As shown in FIG. 9, this hot water supply apparatus includes a heat pump unit 2 having a gas cooler (hot water supply heat exchanger) 1 and a hot water storage unit 4 having a hot water storage tank 3 in which hot water boiled by the gas cooler 1 is stored. It is configured.

  The refrigerant circulation path of the heat pump unit 2 includes a compressor 5, a gas cooler 1, an expansion valve (decompression device) 6, an evaporator 7, and the like. The water circuit of the hot water storage unit 4 includes the circulation pump 8, the gas cooler 1, and hot water storage. It is comprised from the tank 3 grade | etc.,.

  The high-temperature and high-pressure gas refrigerant compressed by the compressor 5 is heat-exchanged with the water stored in the hot water storage tank 3 in the gas cooler 1 to heat and boil the water. The water circulation path from the hot water tank 3 to the gas cooler 1 is provided with an adder (scale suppression means) 9 for supplying an inhibitor that suppresses the generation of scale. With this configuration, since the additive is added to the low-temperature water before boiling with water flow, scale generation in the water circuit of the hot water storage unit 4 is suppressed, and blockage in the water circuit is prevented.

  Patent Document 1 includes a bypass circuit (not shown) that bypasses the adder 9, and a three-way valve (not shown) is provided at a branch point of the bypass circuit. A configuration is described in which the water is circulated by switching.

JP 2011-69572 A

  However, the conventional configuration has a problem in that the amount of the scale inhibitor added cannot be adjusted according to changes in the operating conditions of the hot water supply apparatus, and scale generation cannot be effectively prevented. It was. In addition, the scale inhibitor is consumed more than necessary, which shortens the life of the adder 9 and increases the cost of replacement and maintenance.

  This invention solves the said subject, and suppresses precipitation of a scale, without wasting a scale inhibitor, by adjusting the addition amount of a scale inhibitor appropriately according to the change of the operating condition of a hot water supply apparatus. It is an object of the present invention to provide a hot water supply device that can be used.

In order to solve the conventional problems, a hot water supply apparatus of the present invention includes a hot water storage tank for storing hot water, a heating means for heating water sent from a lower part of the hot water storage tank through a water inlet pipe, and the water inlet pipe. A circulation pump that is disposed in a passage and pumps water in the lower part of the hot water tank to the heating means; a hot water outlet pipe that introduces water heated by the heating means into the upper part of the hot water tank; and the water inlet pipe Scale suppression means for adding a scale inhibitor that suppresses the generation of scale to the water that is disposed on the road and pumped to the heating means, and the heating temperature of the water by the hot water supply load and the heating means is low When the operating condition is such that the hot water supply load and the heating temperature of the water by the heating means are higher than the operating conditions, the circulation rate is reduced so that the flow rate of the water flowing into the heating means is reduced.
The number of rotations of the pump is controlled to increase the concentration of the scale inhibitor contained in the water flowing into the heating means, and the temperature of the water heated by the heating means is also increased .

  As a result, the concentration of the scale inhibitor of the water flowing into the heating means can be adjusted according to the operating conditions where the scale is likely to be generated, thereby preventing the waste of the scale inhibitor and replacing or replenishing it. It is possible to provide a highly reliable hot water supply apparatus that can effectively suppress the precipitation of scale while reducing maintenance and maintenance costs.

  ADVANTAGE OF THE INVENTION According to this invention, the density | concentration of a scale inhibitor can be adjusted according to the operating condition of a hot water supply apparatus, and the hot water supply apparatus which can suppress the production | generation of a scale can be provided, preventing the waste of a scale inhibitor. .

Configuration diagram of hot water supply apparatus in Embodiment 1 of the present invention Explanatory drawing explaining the relationship between the temperature of water and the solubility of scale components Explanatory drawing explaining the relationship between the heating temperature and the heating flow rate of the water of the hot water supply apparatus in embodiment of this invention The block diagram of the hot-water supply apparatus in Embodiment 2 of this invention (A) Explanatory drawing explaining the relationship between the flow rate when the flow rate is small and the concentration of the scale inhibitor in the hot water supply device (b) The relationship between the flow rate when the flow rate is large and the concentration of the scale inhibitor in the hot water supply device Explanatory drawing to explain (A) The block diagram which shows an example of the flow volume adjustment means which sets the diversion ratio of the hot-water supply apparatus (b) The block diagram which shows another example of the flow volume adjustment means which sets the flow-division ratio of the hot-water supply apparatus The block diagram of the hot-water supply apparatus in Embodiment 3 of this invention The block diagram of the hot-water supply apparatus in Embodiment 4 of this invention Configuration diagram of conventional hot water supply equipment

1st invention is a hot water storage tank which stores hot water, a heating means which heats the water sent from the lower part of the hot water storage tank via a water inlet pipe, and a lower part of the hot water tank which is disposed in the water inlet pipe. A circulating pump that pumps water of the water to the heating means, a hot water supply pipe that introduces water heated by the heating means to the upper part of the hot water storage tank, and a pump that is pumped to the heating means. Scale suppression means for adding a scale inhibitor that suppresses the generation of scale to the water to be produced, and the hot water supply load and the hot water supply load and the heating temperature of the water by the heating means are lower than in operating conditions The water flowing into the heating means by controlling the number of revolutions of the circulation pump so as to reduce the flow rate of the water flowing into the heating means when the heating temperature of the water by the heating means is high. Scale included in Thereby increasing the concentration of the control agent, a water heater, characterized in that the higher temperature of the heated water by the heating means.

  As a result, particularly in operating conditions where the scale of the heating means is likely to be generated and the flow rate of water is small, the concentration of the scale inhibitor contained in the water flowing into the heating means is increased. Then, since the concentration of the scale inhibitor contained in the water flowing into the heating means can be reduced, it is possible to effectively suppress the generation of scale according to the operating conditions of the hot water supply apparatus, and to suppress the scale. The life of the agent can be extended, and maintenance and maintenance costs such as replacement and replenishment can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, in the first aspect of the present invention, a bypass circuit that bypasses a part of the water inlet conduit is provided on the water inlet conduit, and the scale suppression means is disposed in the bypass circuit, And a flow rate adjusting means for adjusting a flow rate ratio between the flow rate flowing through the water inlet pipe and the flow rate flowing through the bypass circuit.

  As a result, part of the flowing water is branched and guided to the scale suppressing means, the scale inhibitor is dissolved, and other water flows directly into the hot water supply heat exchanger, so that the water flowing into the heating means The concentration of the scale inhibitor can be adjusted more appropriately according to the operating conditions. That is, when the heating flow rate, which is a condition for easily generating scale, is small, the concentration of the scale inhibitor dissolved in the water flowing into the heating means can be increased, so the hot water supply heat exchanger is clogged due to scale adhesion. It is possible to achieve a hot water supply apparatus that is excellent in reliability.

  Moreover, the life of the scale inhibitor can be extended without wasting the scale inhibitor, and maintenance and maintenance costs such as replacement and replenishment can be reduced.

  Furthermore, when the flow rate of the water flowing from the lower part of the storage tank is changed, the ratio between the flow path resistance of the bypass circuit and the flow path resistance of the water inlet pipe bypassed by the bypass circuit is adjusted to correspond to the flow rate. Therefore, it is possible to achieve an appropriate concentration of the scale inhibitor, and the scale inhibitor can be used efficiently. Therefore, clogging of the hot water supply heat exchanger due to scale adhesion can be prevented to improve the reliability of the hot water supply apparatus, and the life of the scale inhibitor can be extended.

  The third invention is characterized in that, in the first or second invention, the scale inhibitor is mainly composed of polyphosphate.

  As a result, when calcium carbonate is scaled, it is possible to prevent the growth of crystals of calcium carbonate, so the effect of preventing the scale from adhering to and accumulating inside a heat exchanger such as a gas cooler is great. In addition, the life of the heat exchanger such as a gas cooler is prolonged, and maintenance and maintenance costs such as replacement and replenishment can be reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a configuration diagram of a hot water supply apparatus according to Embodiment 1 of the present invention. In FIG. 1, a heating means 55 that is a heat source of a hot water supply apparatus is a heat pump unit that constitutes a heat pump cycle including a compressor 51, a hot water supply heat exchanger 52, a decompression device 53, and an evaporator 54 that absorbs atmospheric heat. Then, carbon dioxide whose refrigerant pressure on the high pressure side is equal to or higher than the critical pressure is used as the refrigerant.

  Water is supplied to the hot water storage tank 57 stored in the hot water storage unit 56 through a water supply pipe 58 connected to the lower part of the hot water storage tank 57, and hot water in the upper part of the hot water storage tank 57 passes through the hot water supply pipe 59 and is mixed with the hot water supply mixing valve 60. The hot water is mixed with the hot water at a predetermined temperature, and then hot water is supplied from the hot water supply terminal such as the faucet 62 through the hot water supply pipe 61.

  In addition, a boiling circuit is configured by sequentially connecting the water inlet pipe 64, the hot water supply heat exchanger 52, the hot water outlet pipe 65, and the upper part of the hot water tank 57 from the lower part of the hot water tank 57, and is disposed in the incoming water pipe 64. The water pumped from the hot water storage tank 57 by the circulation pump 63 is heated by the high-temperature refrigerant in the hot water supply heat exchanger 52 and stored from above the hot water storage tank 57.

The hot water supply pipe 65 connected to the water outlet of the hot water supply heat exchanger 52 is provided with temperature detecting means 66 for detecting the hot water heated up by the heating means, that is, the heating temperature. Furthermore, a scale suppression means 68 filled with a scale inhibitor 67 is provided on the water inlet pipe 64 connecting the hot water tank 57 and the heating means 55.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In the hot water supply apparatus of FIG. 1, when there is a request for a boiling operation for generating hot water, a hot water supply heating operation using atmospheric heat is performed by the heat pump unit which is the heating means 55.

  In this case, a high-temperature and high-pressure refrigerant discharged from the compressor 51 is heated to a hot water supply heat exchanger 52 where heat is exchanged with water sent from the lower part of the hot water tank 57 to dissipate heat. The pressure is reduced by the pressure reducing device 53, and the evaporator 54 absorbs heat from the atmosphere, gasifies it, and returns to the compressor 51.

  At this time, the number of revolutions of the circulation pump 63 is controlled so that the temperature (heating temperature) on the outlet side of the hot water supply heat exchanger 52 detected by the temperature detection means 66 becomes a predetermined temperature, so that the hot water supply heat exchanger 52 Then, the water sent from the lower part of the hot water storage tank 57 through the water inlet pipe 64 is heated, becomes hot water of a predetermined temperature, flows in from the upper part of the hot water storage tank 57 and is stored.

  Here, since the scale suppression means 68 filled with the scale inhibitor 67 is disposed on the water inlet pipe 64, the water sent from the lower part of the hot water storage tank 57 by the circulation pump 63 causes the scale suppression means 68 to flow. Flowing.

  In the scale suppressing means 68, the scale inhibitor 67 is dissolved in water, and the water in which the scale inhibitor 67 is dissolved flows into the hot water supply heat exchanger 52 and is heated to a predetermined temperature. At this time, the scale inhibitor 67 contained in the water suppresses the growth of crystals such as calcium carbonate, which are precipitated in the hot water supply heat exchanger 52, and prevents the generation of scale.

  As the scale inhibitor 67, the scale suppression means 68 is filled with particles containing polyphosphate as a main component. Typical polyphosphates include sodium tripolyphosphate and sodium hexametaphosphate, but other polyphosphates may be used. Moreover, you may use what has low molecular polymers, such as a phosphonic acid and a carboxylic acid type polymer electrolyte, as a main component.

  Next, the relationship between scale precipitation and water temperature will be described. FIG. 2 is an explanatory diagram for explaining the solubility of the scale component in water by taking the temperature of water on the horizontal axis and the solubility of the scale component on the vertical axis. As shown in FIG. 2, the higher the temperature of water, the smaller the solubility of scale components (for example, calcium carbonate, etc.), which crystallizes and precipitates in water.

  In the case of a hot water storage type hot water supply apparatus, hot water corresponding to the hot water supply load of the day is mainly stored in the hot water storage tank 57 using late-night power with a low electricity bill. Here, the hot water supply load is high in the frequency and amount of hot water used, is large in winter when the outside air temperature is low, and is small in summer when the outside air temperature is high.

  The hot water supply load that varies from season to season is dealt with by changing the heating temperature of the hot water stored in the hot water storage tank 57 (for example, 65 ° C. to 90 ° C.). That is, in winter when the hot water supply load is large, the water is boiled and stored at about 85 ° C. (˜90 ° C.), for example, and in summer when the hot water supply load is small, the heating temperature is lower than winter, for example, about 65 ° C. to 70 ° C. Store hot water. This heating temperature is a temperature in the middle period.

  Therefore, the scale which adheres and accumulates especially on the surface of the water passage etc. in the hot water supply heat exchanger 52 is often generated under a situation where the heating temperature is high, such as a heating operation in winter.

  Therefore, if the concentration of the scale inhibitor 67 dissolved in water is increased under operating conditions where scale deposition is likely to occur, that is, conditions where the heating temperature is high, scale deposition can be effectively suppressed.

  Here, in the case of a hot water storage type hot water supply apparatus, generally, the heating capacity is substantially constant even when the outside air temperature changes. Moreover, the temperature of the tap water used as water supply to a hot water supply apparatus becomes low, so that outside temperature is generally low. FIG. 3 is an explanatory diagram showing the relationship between the heating temperature and the heating flow rate, where the horizontal axis represents the heating temperature and the vertical axis represents the heating flow rate, that is, the flow rate of water heated by the heating means 55.

  Assuming that the heating capability of the heating means 55 is substantially constant, the heating temperature can be handled by adjusting the flow rate (heating flow rate) of water flowing into the heating means 55 as shown in FIG. For example, by reducing the heating flow rate, the time during which water stays in the heating means 55 is longer than when the heating flow rate is large, so the amount of heat that water per unit flow rate obtains from the high-temperature refrigerant increases. Therefore, the heating temperature can be increased. Therefore, as shown in FIG. 3, the rotational speed of the circulation pump 63 is controlled so that the flow rate of water flowing into the heating means 55 is smaller when the target value of the heating temperature is higher than when the target value is lower. . Thereby, it can respond to various heating temperatures.

  Further, when the heating flow rate is reduced, that is, when the flow rate of water flowing into the heating means 55 is reduced, the time during which the water flowing through the water inlet pipe 64 stays in the scale suppression means 68 is also smaller than when the flow rate is high. become longer. Therefore, since the time for which the water and the scale inhibitor 67 come into contact with each other is increased and the amount of the scale inhibitor 67 dissolved in water can be increased, the concentration of the scale inhibitor 67 in the water flowing into the heating means 55 is increased. Can be made.

  As described above, when the number of rotations of the circulation pump 63 is controlled so that the flow rate of water flowing into the heating means 55 is reduced in a condition in which scale is likely to precipitate, that is, in an operating condition where the target value of the heating temperature is high, The temperature can be increased, and the scale inhibitor 68 can increase the amount of the scale inhibitor 67 dissolved in water per unit flow rate, that is, the concentration of the scale inhibitor in the unit flow rate water. Precipitation can be suppressed.

  Therefore, since the concentration of the scale inhibitor dissolved in water can be adjusted according to the operating conditions of the hot water supply device, the generation of scale can be suppressed without wasting the scale suppressant, and the highly reliable hot water supply device Can be provided.

(Embodiment 2)
FIG. 4 is a configuration diagram of a hot water supply apparatus according to Embodiment 2 of the present invention. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 4, a heating means 55 that is a heat source of a hot water supply device is a heat pump unit that constitutes a heat pump cycle including a compressor 51, a hot water supply heat exchanger 52, a decompression device 53, and an evaporator 54 that absorbs atmospheric heat. Then, carbon dioxide whose refrigerant pressure on the high pressure side is equal to or higher than the critical pressure is used as the refrigerant.

  Water is supplied to the hot water storage tank 57 stored in the hot water storage unit 56 through a water supply pipe 58 connected to the lower part of the hot water storage tank 57, and hot water in the upper part of the hot water storage tank 57 passes through the hot water supply pipe 59 and is mixed with the hot water supply mixing valve 60. The hot water is mixed with the hot water at a predetermined temperature, and then hot water is supplied from the hot water supply terminal such as the faucet 62 through the hot water supply pipe 61.

  In addition, a boiling circuit is configured by sequentially connecting the water inlet pipe 64, the hot water supply heat exchanger 52, the hot water outlet pipe 65, and the upper part of the hot water tank 57 from the lower part of the hot water tank 57, and is disposed in the incoming water pipe 64. The water pumped from the hot water storage tank 57 by the circulating pump 63 is heated by the high-temperature refrigerant in the hot water supply heat exchanger 52 and stored from above the hot water storage tank 57.

  The hot water supply pipe 65 connected to the water side outlet of the hot water supply heat exchanger 52 is provided with temperature detecting means 66 for detecting the temperature of the hot water heated by the heating means. Further, in the water intake pipe 64, a bypass circuit 74, which is another water intake pipe that bypasses a part of the water, is provided in parallel, and a scale suppression means 68 filled with a scale inhibitor 67 is provided on the bypass circuit 74. . As a result, the water intake pipe 64 where the scale suppression means 68 is not provided becomes the main circuit, and the bypass circuit 74 in which the scale suppression means 68 is arranged forms a sub circuit of the water intake pipe 64.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 4, a hot water supply heating operation for boiling the hot water storage tank 57 will be described. When there is a request to boil water stored in the hot water storage tank 57, a hot water supply heating operation using atmospheric heat is performed by the heat pump unit which is the heating means 55. In this case, the high-temperature and high-pressure refrigerant discharged from the compressor 51 is heated to a hot water supply heat exchanger 52, where it exchanges heat with the water sent from the lower part of the hot water tank 57 and dissipates heat. The pressure is reduced by the pressure reducing device 53, and the evaporator 54 absorbs heat from the atmosphere, gasifies it, and returns to the compressor 51.

  At this time, the hot water supply heat exchanger 52 controls the number of revolutions of the circulation pump 63 so that the outlet temperature of the hot water supply heat exchanger 52, that is, the temperature detected by the temperature detecting means 66 becomes a predetermined temperature. The water sent from the lower part of the hot water tank 57 through the water inlet pipe 64 is heated to become hot water having a predetermined temperature, and flows in from the upper part of the hot water tank 57 and is stored.

  Here, since the bypass circuit 74 provided with the scale suppressing means 68 filled with the scale inhibitor 67 is connected in parallel to the water inlet pipe 64, the water sent from the lower part of the hot water tank 57 by the circulation pump 63. A part of the gas flows to the bypass circuit 74 side provided with the scale suppressing means 68 at the connection portion A, and the rest flows to the water inlet pipe 64 side not provided with the scale suppressing means 68.

  Then, the water that has flowed to the bypass circuit 74 side flows into the scale suppression means 68 and dissolves the scale inhibitor 67, and then flows into the inlet pipe 64 that does not include the scale suppression means 68 at the connection portion B. Mix with water. The water mixed with the water flowing through the water inlet pipe 64 at the connection portion B and dissolved in the scale inhibitor 67 flows into the hot water supply heat exchanger 52 and is heated to a predetermined temperature. At this time, the scale inhibitor 67 contained in the water suppresses the growth of crystals such as calcium carbonate generated in the hot water supply heat exchanger 52, and prevents the generation of scale.

  FIG. 2 is an explanatory diagram for explaining the solubility of the scale component in water by taking the temperature of water on the horizontal axis and the solubility of the scale component on the vertical axis. As shown in FIG. 2, the higher the temperature of water, the smaller the solubility of scale components (for example, calcium carbonate, etc.), which crystallizes and precipitates in water. That is, many scales that adhere to and accumulate on the surface of the water passage of the hot water supply heat exchanger 52 and the like are generated under operating conditions where the heating temperature is high.

Moreover, as shown in FIG. 3, when heating to the temperature (heating temperature) which stores the water supplied from a water supply in the hot water storage tank 57 on the conditions with a fixed heating capability, it flows into a heating means and is heated, It is possible to respond by adjusting the flow rate (heating flow rate) of the water stored in the hot water tank 57. That is, when the heating flow rate is small, compared with the case where the heating flow rate is large, in the heating means 55, the amount of heat obtained from the high-temperature refrigerant by the water per unit flow rate increases, so that the heating temperature can be increased.

  As described above, the higher the heating temperature, that is, the smaller the heating flow rate, the easier the scale is to be generated and the easier it is to adhere to the water-side flow path surface of the hot water supply heat exchanger 52. Therefore, in order to prevent scale generation and particularly adhesion of the scale to the water-side flow path surface of the hot water supply heat exchanger 52, the smaller the heating flow rate, the more the water flows into the hot water supply heat exchanger 52. What is necessary is just to enlarge the density | concentration (mass of the scale inhibitor contained per unit mass of water) of a scale inhibitor.

  FIG. 5 is an explanatory diagram for explaining the flow rate flowing through the bypass circuit 74 and the water inlet pipe 64 and the concentration of the scale inhibitor 67 at that time. 5A shows a case where the heating flow rate is small, and FIG. 5B shows a case where the heating flow rate is large.

  The bypass circuit 74 is connected to a connection part A and a connection part B in the middle of the water inlet pipe 64 (the connection part A is upstream of B). The bypass circuit 74 includes a scale suppression means 68 in which the scale suppression agent 67 is accommodated.

  In the case of FIG. 5 (a), the flow rate flowing to the inlet pipe 64 side and the flow rate flowing to the bypass circuit side divided at the connection portion A are J1 and K1, respectively, and in the case of FIG. To do. Moreover, the density | concentration of the scale inhibitor 67 after exiting the exit part C of the scale suppression means 68 is set to N1 (C) in the case of FIG. 5 (a), N2 (C) in the case of FIG.5 (b). To do.

  Here, in the case of FIG. 5A, the flow rate is smaller than in the case of FIG. Therefore, the time for which the water flowing into the scale suppression means 68 and the scale suppression agent 67 come into contact with each other becomes longer, and as a result, the concentration after exiting the scale suppression means 68 becomes larger in FIG. That is, the following relationship is established.

  Further, when the concentration of the scale inhibitor 67 on the downstream side of the connecting portion B is N1 (B) in the case of FIG. 5A and N2 (B) in the case of FIG. Is obtained.

  Furthermore, the diversion ratio of the flow rate that flows to the inlet pipe 64 side and the bypass circuit 74 side,

Then, the relationship between the concentration of the scale inhibitor 67 on the downstream side of the connection B and the concentration of the scale inhibitor 67 after exiting the outlet C of the scale suppression means 68 is as follows.

  From the above (Formula 1) and (Formula 5), the relationship of the concentration of the scale inhibitor 67 on the downstream side of the connection portion B flowing into the hot water supply heat exchanger 52 is as follows.

  As can be seen from (Expression 6), the concentration of the scale inhibitor 67 flowing into the hot water supply heat exchanger 52 increases as the flow rate decreases. The smaller the flow rate is, the higher the heating temperature and the easier the scale is generated. However, the concentration of the scale inhibitor 67 can be increased, and the scale adhesion to the hot water supply heat exchanger 52 or the like can be prevented or reduced. can do.

  Therefore, the flow rate of the water flowing into the scale suppression means 68 by diverting the water flowing into the heating means 55 by the bypass circuit 74 capable of setting the diversion ratio as shown in FIGS. Thus, the amount of the scale inhibitor 67 dissolved in water can be adjusted.

  FIG. 6 is an explanatory diagram for explaining a method of setting a flow dividing ratio of the flow rate flowing to the bypass circuit 74 side and the water inlet pipe 64 side.

  In FIG. 6A, the flow path resistance between the connecting portion A and the connecting portion B of the water inlet pipe 64 is changed by, for example, configuring the pipe cross-sectional area to be different from that of the bypass circuit 74. The pressure loss between AB is set, and the branching ratio of the branch flow rate can be determined according to the differential pressure.

  In addition, when the flow path resistance of the scale suppression means 68 is large, as shown in FIG. 6B, the configuration is such that fluid dynamic pressure is applied to the bypass circuit 74 side provided with the scale suppression means 68, and between the points AB. By changing the cross-sectional area of the pipe of the incoming water pipe 64, the pressure loss between the points AB can be set, and the diversion ratio of the branch flow rate can be determined as necessary according to the differential pressure.

  As described above, since a part of the hot water from the lower part of the hot water tank is branched and the scale inhibitor 67 is dissolved therein, the other hot water flows into the hot water supply heat exchanger 52 without flowing through the scale suppressing means 68. In addition, waste of the scale inhibitor can be prevented. Therefore, the life of the scale inhibitor is prolonged, and there is an effect of reducing maintenance and maintenance costs such as replacement and replenishment.

Furthermore, in order to boil hot water to a desired heating temperature, when the flow rate of water flowing into the heating means 55 is reduced, the concentration of the scale inhibitor 67 of water flowing into the heating means 55 can be increased. Since the scale suppression means 68 can be used in accordance with the operating conditions of the hot water supply device, clogging of the hot water heat exchanger 52 due to scale deposition and adhesion can be prevented, so that the reliability of the hot water supply device can be improved. it can.

(Embodiment 3)
FIG. 7 is a configuration diagram of a hot water supply apparatus according to Embodiment 3 of the present invention.

  In this embodiment, parts that are the same as those in the other embodiments are given the same reference numerals, and detailed descriptions thereof are omitted.

  As shown in FIG. 7, the hot water supply apparatus in the present embodiment includes a flow rate adjusting means 69 between the connection portion A and the connection portion B of the water inlet pipe 64, and control for controlling the operation of the flow rate adjustment means 69. Means 70 are provided.

  As the flow rate adjusting means 69, for example, a flow rate control valve generally used in a hot water supply apparatus can be used, and the flow rate is adjusted by changing the flow passage cross-sectional area through which the fluid passes by driving a stepping motor. be able to.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  In FIG. 7, when the concentration of the scale inhibitor 67 downstream of the connection portion B is changed to a predetermined concentration, the flow passage resistance of the flow rate adjusting means 69 is changed (for example, the flow passage cross-sectional area is changed), and the connection portion A is changed. And the ratio of the flow volume (branch flow volume) which branches and flows to the scale suppression means 68 side is changed by changing the pressure loss between the connection parts B.

  That is, if the flow path resistance of the flow rate adjusting means 69 is increased (for example, the flow path cross-sectional area is decreased by decreasing the valve opening degree), the pressure loss between the connection part A and the connection part B increases. The ratio of flow rate can be increased. Conversely, if the flow path resistance of the flow rate adjusting means 69 is reduced (for example, the flow path cross-sectional area is increased), the ratio of the branch flow rate can be reduced, thereby adjusting the branch flow rate.

  As a factor that the scale adheres and grows in the hot water supply heat exchanger 52, there is a temperature (heating temperature) stored in the hot water storage tank 57. The higher the heating temperature, the greater the scale generation and growth. Further, the heating temperature and the heating flow rate have a relationship as shown in FIG. That is, the smaller the heating flow rate, the easier the scale is generated and the faster the scale grows.

  Therefore, the ratio of the branch flow rate is set so that the concentration of the scale inhibitor 67 contained in the hot water flowing into the heating means 55 is such that the scale generation and growth are suppressed with respect to the heating flow rate. do it. At this time, the relationship between the concentration of the scale inhibitor 67 without scale generation and growth and the heating flow rate may be obtained in advance, and this relationship may be stored in the remote controller 72.

  The ratio of the branch flow rate is adjusted by adjusting the flow rate adjusting means 69, but the required flow rate can be obtained by adjusting the rotational speed of the circulation pump 63.

  Thus, according to the heating flow rate, the concentration of the scale inhibitor 67 that can suppress the generation of scale can be set by using only one flow rate adjusting means 69, so that it depends on the operating conditions of the hot water supply device. Thus, the concentration of the scale inhibitor 67 of the water flowing into the heating means 55 can be adjusted appropriately. Therefore, it is possible to provide a highly reliable hot water supply apparatus that prevents scale deposition and adhesion over a long period of time, and the life of the scale inhibitor 67 is prolonged, thereby reducing maintenance and maintenance costs such as replacement and replenishment. There is an effect that can be.

  In addition, the temperature (heating temperature) of the hot water stored in the hot water tank 57 is generally about 65 to 90 ° C. The higher the heating temperature, the lower the heating flow rate and the easier the generation and growth of the scale. However, if the heating temperature is around 65 ° C., the generation of scale is small and there is almost no growth.

  Therefore, the control unit 70 may be configured to adjust the flow rate adjusting unit 69 so that the concentration of the scale inhibitor 67 is minimized when the heating flow rate corresponds to such a heating temperature condition. That is, the flow path resistance of the flow rate adjusting means 69 is controlled to be the minimum (the flow path cross-sectional area through which the fluid of the flow rate adjusting means 69 passes is maximized).

  In this way, when the heating flow rate is such that there is little generation of scale and little growth, the concentration of the scale inhibitor 67 can be set to the minimum, so that the scale inhibitor is not always increased without increasing the scale inhibitor concentration. This has the effect of extending the life of the battery and reducing maintenance and maintenance costs such as replacement and replenishment.

(Embodiment 4)
FIG. 8 is a configuration diagram of a hot water supply apparatus according to Embodiment 4 of the present invention. In this embodiment, the same parts as those in the other embodiments are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 8, flow rate adjusting means 69 (three-way valve) capable of adjusting the flow rate flowing through the two outlet-side flow paths by changing the cross-sectional areas of the two outlet-side flow paths is provided at the connection portion A. That is, the inlet side is connected to the inlet pipe 64 on the hot water tank 57 side, one of the two outlet sides is connected to the inlet pipe 64 side on the heating means 55 side, and the other is connected to the bypass circuit 74 side. The control means 70 controls the operation of the flow rate adjusting means 69 so that the flow rates on the respective outlet sides have the required diversion ratio.

  As the flow rate adjusting means 69, for example, a mixing valve generally used in a hot water supply device can be used. By driving a stepping motor, the flow rate is changed by changing the cross-sectional area of the outlet side through which the fluid passes. To change.

  About the hot water supply apparatus comprised as mentioned above, the operation | movement and an effect | action are demonstrated below. In the hot water supply apparatus shown in FIG. 8, when the concentration of the water scale inhibitor 67 downstream of the connection portion B is changed to a predetermined concentration, the flow path resistance of the flow rate adjusting means 69 is changed (for example, the flow path cross-sectional area is changed). ) Thereby, the ratio of the flow rate (branch flow rate) branched and flowing to the bypass circuit 74 side (scale suppression means 68 side) and the flow rate (branch flow rate) flowing through the water inlet pipe 64 not provided with the scale suppression means 68 is changed. Can do. In other words, the flow rate adjusting means 69 appropriately adjusts both the flow rate flowing through the water inlet pipe 64 and the flow rate flowing through the bypass circuit 74.

  As a factor that the scale adheres and grows in the hot water supply heat exchanger 52, there is a temperature (heating temperature) of water stored in the hot water storage tank 57. The higher the heating temperature, the greater the scale generation and growth. Further, the heating temperature and the heating flow rate have a relationship as shown in FIG. Therefore, the smaller the heating flow rate, the easier the scale is generated and the faster the scale grows.

  Therefore, if the ratio of the branch flow rate is set by the flow rate adjusting unit 69 so that the concentration of the scale inhibitor 67 contained in the hot water flowing into the heating unit 55 becomes a concentration at which scale generation and growth are suppressed. Good. At this time, a relationship between the concentration of the water scale inhibitor 67 capable of suppressing scale generation and growth and the heating flow rate is obtained in advance, and this relationship may be stored in the remote controller 72. .

  The ratio of the branch flow rate is adjusted by adjusting the flow rate adjusting means 69, but the required flow rate can be obtained by adjusting the rotational speed of the circulation pump 63.

  Thus, since the density | concentration of the scale inhibitor 67 which does not generate | occur | produce a scale can be set according to a heating flow rate, according to the operating condition of a hot water supply apparatus, the scale inhibitor 67 of the hot water which flows into the heating means 55 is set. Since the concentration can be adjusted appropriately, it is possible to provide a highly reliable hot water supply apparatus that prevents the deposition and adhesion of scale over a long period of time, and the life of the scale inhibitor 67 is increased, and replacement and replenishment thereof are possible. There is an effect that maintenance and maintenance costs can be reduced.

  As described above, the hot water supply apparatus according to the present invention appropriately adjusts the amount of dissolution of the scale inhibitor according to the operating conditions, improves the reliability of the hot water supply apparatus, and extends the life of the scale suppression means. Therefore, it can be applied to hot water supply devices for home use and business use.

55 Heating means 57 Hot water storage tank 63 Circulation pump 64 Water inlet pipe 65 Hot water outlet pipe 67 Scale inhibitor 68 Scale suppressing means 69 Flow rate adjusting means 74 Bypass circuit

Claims (3)

A hot water storage tank for storing hot water,
A heating means for heating the water sent from the lower part of the hot water storage tank through the water inlet line;
A circulation pump that is disposed in the water inlet pipe and pumps water below the hot water tank to the heating means;
A hot water outlet pipe for introducing water heated by the heating means into the upper part of the hot water storage tank;
A scale suppressing means for adding a scale inhibitor that suppresses generation of scale to the water that is disposed on the water inlet pipe and is pumped to the heating means; and
The water that flows into the heating means when the hot water supply load and the heating temperature of the water by the heating means are higher in operating conditions than when the hot water supply load and the heating temperature of the water by the heating means are low. The rotational speed of the circulation pump is controlled so as to reduce the flow rate of the water, and the concentration of the scale inhibitor contained in the water flowing into the heating means is increased, and the temperature of the water heated by the heating means is also increased. A hot water supply apparatus characterized by the above. A bypass circuit for bypassing a part of the water inlet pipe is provided on the water inlet pipe, and the scale suppression means is disposed in the bypass circuit, and flows to the water inlet and the bypass circuit. The hot water supply apparatus according to claim 1, further comprising a flow rate adjusting unit that adjusts a flow rate ratio with the flow rate. The hot water supply apparatus according to claim 1 or 2, wherein the scale inhibitor is mainly composed of polyphosphate.