JP2009030861A - Hot water supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply system capable of responding to unpredictable disturbance factors and minimizing rise in the temperature of supplied hot water. <P>SOLUTION: The hot water supply system 1 is provided with a hot water storage tank 2 for storing supplied water and hot water; a heating source 3 for heating water sent out from a bottom part of the hot water storage tank 2; a high temperature hot water supply piping 52a serving as hot water supply piping for supplying high temperature hot water stored in the hot water supply tank 2; a mixing valve 6e for mixing hot water from the high temperature hot water supply piping 52a or medium temperature hot water supply piping 52b serving as hot water supply piping with water from a water supply pipe 5; a mixed hot water sending piping 54 connected to the mixing valve 6e and sending mixed hot water; a temperature sensor 8 arranged in the mixed hot water sending piping 54 and measuring the temperature of the mixed hot water; and a control part 4 acquiring information from the temperature sensor 8 and controlling the mixing valve 6e. The control part 4 performs control so as to drive the mixing valve 6e to a direction to raise a mixing ratio of water until decline speed of the hot water temperature becomes a predetermined value, when the temperature of the mixed hot water is increased by a predetermined value. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a hot water supply system capable of performing hot and cold water mixing control using an electric mixing valve.

  Conventionally, a hot water supply system is known in which water is boiled by a heat pump and hot water stored in a hot water storage tank is supplied to a hot water use terminal such as a currant or a dishwasher. In this hot water supply system, hot water heated by a heat pump circuit is stored in a hot water storage tank, the hot water stored in the hot water is taken out from a hot water discharge pipe, mixed with water supplied from the hot water supply pipe, adjusted to a predetermined hot water temperature, and a hot water supply terminal. Etc., and is realized by controlling a plurality of mixing valves.

  When the mixing valve is specifically controlled, there are various problems depending on the control method. For example, when hot water is supplied from another system (high temperature hot water) during hot water supply such as hand washing (mixed hot water), the hot water temperature of hand washing is lowered due to a decrease in hot water supply pressure. Conversely, when the hot water supply from another system is stopped, the hot water supply temperature for hand washing rises due to an increase in the hot water supply pressure. If the hot water temperature rises suddenly, there is a danger of burns to users who are washing their hands.

Therefore, conventionally, as disclosed in Japanese Patent Application Laid-Open No. 2006-343032 (Patent Document 1), for example, by a button input such as a hot water filling function of a bath, a plurality of usage-side mixing valves are used independently. By performing so-called feed-forward control that predicts and compensates for a predetermined amount of transient hot water temperature when used simultaneously, it suppresses the transient fluctuation when the usage pattern changes and stabilizes the load. It is known that the hot water temperature can be supplied to the side.
JP 2006-343032 A

  However, in the above conventional example, when a preset operation is performed, feedforward control for predicting the occurrence of disturbance and suppressing temperature fluctuation is performed, and when an unpredictable disturbance occurs. However, there is a problem that the feedforward control cannot be performed and the temperature fluctuation cannot be suppressed appropriately.

  The present invention has been invented in view of the above-described background art, and an object thereof is to provide a hot water supply system capable of minimizing an increase in hot water supply temperature in response to an unpredictable disturbance factor. Is an issue.

  In order to solve the above-mentioned problems, in the invention according to claim 1 of the present application, a water supply pipe is connected to the bottom portion, a hot water storage tank for storing the water supply and the heated hot water, and water supplied from the bottom portion of the hot water storage tank are heated. Hot water supply provided with a heating source that connects the heating source and a hot water storage tank to supply heated hot water to the hot water storage tank, and a hot water supply pipe that discharges hot or medium hot water stored in the hot water storage tank In the system, a mixing valve that mixes hot water from the hot water supply pipe and water from the water supply pipe, a mixed hot water supply pipe that is connected to the mixing valve and supplies mixed hot water, and a mixed hot water pipe that is provided in the mixed hot water supply pipe. A temperature sensor that measures the temperature of the hot water and a control unit that acquires information from the temperature sensor and controls the mixing valve, and the control unit is configured to supply hot water when the temperature of the mixed hot water rises to a predetermined value. Mix the mixing valve with water until the temperature decrease rate reaches a predetermined value. It is characterized by performing control to drive the same in a direction for increasing the.

  In the hot water supply system according to the first aspect of the present invention, a temperature sensor that is disposed in the mixed hot water supply pipe and measures the hot water temperature of the mixed hot water, and a control that controls the mixing valve by acquiring information from the temperature sensor. The controller controls the driving of the mixing valve in the direction of increasing the water mixing ratio until the hot water temperature decreases to a predetermined value when the hot water temperature of the mixed hot water increases by a predetermined value. Therefore, when the control for returning the raised hot water temperature to the original hot water temperature is executed, the driving time of the mixing valve in which the hot water temperature does not undershoot can be set in advance. As a result, even if the hot water temperature rises due to an unforeseen disturbance, it can be immediately restored to the original hot water temperature, so that the rise in hot water temperature can be minimized in response to unpredictable disturbance factors. It can be suppressed and a stable hot water temperature can be provided. Further, complicated feedback control and feedforward control are unnecessary, the control unit can be simplified, and cost can be reduced.

  1 to 3 show a hot water supply system according to a first embodiment of the present invention. As shown in FIG. 1, a hot water supply system 1 has a water supply pipe 5 connected to the bottom, a hot water storage tank 2 for storing the hot water and heated hot water, and heating for heating water sent from the bottom of the hot water storage tank 2. Hot water is a source 3, a hot water supply pipe 51 b that connects the heating source 3 and the hot water storage tank 2 to send heated hot water to the hot water storage tank 2, and a hot water hot water that is a hot water outlet pipe for hot water stored in the hot water storage tank 2 A hot water supply pipe 52a and a hot water hot water supply pipe 52b, which is a hot water supply pipe for discharging intermediate hot water, are mixed with hot water from the hot water hot water supply pipe 52a or the hot water hot water supply pipe 52b and water from the water supply pipe 5. A mixing valve 6e, a mixing hot water supply pipe 54 connected to the mixing valve 6e for feeding the mixed hot water, a temperature sensor 8 disposed in the mixed hot water supply pipe 54 for measuring the hot water temperature of the mixed hot water, and a temperature The information from the sensor 8 is acquired and the mixing valve 6 The control unit 4 controls the mixing valve 6e so that when the hot water temperature of the mixed hot water rises by a predetermined value, the mixing valve 6e is mixed with the water until the hot water temperature decreases to a predetermined value. It controls to drive in the direction to raise the.

  Hereinafter, the hot water supply system of this embodiment will be described in more detail. As shown in FIG. 1, a hot water supply system 1 controls a hot water storage tank 2 and additional tanks 21a and 21b for storing hot water and heated hot water, a heating source 3 that is a heat pump for heating the hot water, and the entire hot water supply system 1. And a control unit 4. The hot water storage tank 2 is connected to the water supply pipe 5 at the bottom and receives water to store water. The heating source 3 is connected to the bottom of the hot water storage tank 2 by a pipe 51a, and the water at the bottom of the hot water storage tank 2 is sucked and heated by a built-in hot water supply pump. The hot water outlet of the heating source 3 is connected to the switching valve 6a by a pipe 51b. The switching valve 6a switches the hot water supply destination from the heating source 3 to a pipe 51c connected to the middle layer of the hot water storage tank 2 and a pipe 51d connected to the high-temperature hot-water supply pipe 52a. One end of the high-temperature hot-water supply piping 52a is connected to the switching valve 6b, and the switching valve 6b switches the hot water supply destination from the high-temperature hot-water supply piping 52a to the top of the hot water storage tank 2 and the top of the expansion tank 21a. And the bottom part of the expansion tank 21a and the top part of the expansion tank 21b are connected by the piping 51f, and the bottom part of the expansion tank 21b is connected with the heating source 3 via the piping 51g and 51a.

  The other end of the high temperature hot water supply pipe 52a is connected to the high temperature hot water outlet, and is connected to the return pipe 53 in the middle. The return pipe 53 has a hot water supply pump 7 and a water stop valve 6c in the pipe, and is connected to the middle layer of the hot water storage tank 2 via the pipe 51c. An intermediate temperature hot water discharge pipe 52b is connected to the middle layer of the hot water storage tank 2, and the intermediate temperature hot water discharge pipe 52b is connected to the switching valve 6d. The switching valve 6d is also connected to a pipe 51h branched from the high-temperature hot water discharge pipe 52a, and switches between high-temperature hot water from the top of the hot water storage tank 2 and medium-temperature hot water from the middle layer, and supplies hot water to the mixing valve 6e. The mixing valve 6e is connected to a pipe from the switching valve 6d and a pipe 51 branched from the water supply pipe 5. The hot water from the switching valve 6d and the water supplied from the pipe 51 are mixed to supply hot water to the intermediate temperature outlet. To do.

  Next, the operation of the hot water supply system 1 according to the present embodiment configured as described above will be described with reference to the drawings. FIG. 2 shows the operation during boiling of hot water. When the water in the hot water storage tank 2 is heated to a high temperature, the control unit 4 switches the switching valve 6a to the top side (pipe 51d) of the hot water storage tank 2 and switches the switching valve 6b to the hot water storage tank 2 side. The controller 4 drives the hot water supply pump of the heating source 3, sucks the water at the bottom of the hot water storage tank 2 into the heating source 3, and sends the heated hot water to the switching valve 6a through the pipe 51b. The sent hot water flows to the pipe 51d through the switching valve 6a, passes through the high-temperature hot water tap pipe 52a, and is sent to the top of the hot water storage tank 2 through the switching valve 6b (arrows A, B, C).

  When boiling the water in the expansion tanks 21a and 21b to a high temperature, the control unit 4 switches the switching valve 6a to the top side (pipe 51d side) of the hot water storage tank 2, and switches the switching valve 6b to the expansion tank 21a side (pipe 51e). Switch to. The controller 4 drives the hot water supply pump of the heating source 3, sucks the water at the bottom of the expansion tank 21b into the heating source 3, and sends the heated hot water to the switching valve 6a through the pipe 51b. The sent hot water flows to the pipe 51d through the switching valve 6a, passes through the high-temperature hot water tap pipe 52a, passes through the pipe 51e through the switching valve 6b, and is sent to the top of the expansion tank 21a. (Arrows G, B, E, F).

  The hot water heated to a high temperature is appropriately switched to one of the hot water storage tank 2 and the additional tanks 21a and 21b, and the hot water is always supplied to the hot water storage tank 2 having the intermediate hot water outlet piping 52b in the middle layer. Since it can be secured in the middle layer portion, it is not necessary to provide the hot water outlet piping in the additional tanks 21a and 21b.

When boiling the water in the hot water storage tank 2 to an intermediate temperature, the control unit 4 switches the switching valve 6a to the middle layer side (the pipe 51c side) of the hot water storage tank 2. The controller 4 switches the heated hot water to the switching valve 6a.
Through the pipe 51c and supply hot water to the middle layer of the hot water storage tank 2 (arrows A and D). The medium temperature hot water is not made by mixing hot water and feed water, but is boiled to a medium temperature, so that energy efficiency can be improved.

  FIG. 3 shows the operation at the time of hot water. When discharging hot water from the hot water storage tank 2, the control unit 4 switches the switching valve 6b to the hot water storage tank 2 side. When the high temperature hot water outlet is opened, the supply water enters the bottom of the hot water storage tank 2 from the water supply pipe 5 due to the supply water pressure, and the high temperature hot water at the top of the hot water storage tank 2 passes through the high temperature hot water tap pipe 52a via the switching valve 6b. Hot water is fed to the hot outlet (arrows H, I, J). When discharging hot water from the expansion tanks 21a and 21b, the control unit 4 switches the switching valve 6b to the expansion tank 21a side. When the high temperature hot water outlet is opened, water supply enters the bottom of the hot water storage tank 2 from the water supply pipe 5 due to the water supply pressure, and enters the bottom of the expansion tank 21b through the pipes 51a and 51g. Since the top of the expansion tank 21b and the bottom of the expansion tank 21a are connected by the pipe 51f, the hot water at the top of the expansion tank 21a passes through the pipe 51e due to the feed water pressure, and passes through the switching valve 6b to the high temperature hot water supply pipe 52a. And is sent to the hot tap (arrows H, K, L, M, J).

  When discharging the medium temperature hot water, the control unit 4 switches the switching valve 6d to the medium temperature hot water discharge pipe 52b side when the hot water storage tank 2 has the medium temperature hot water. Moreover, the control part 4 switches the switching valve 6b to the expansion tank 21a side, and stops the hot water from the top part of the hot water storage tank 2. FIG. When the intermediate temperature hot water outlet is opened, the supply water enters the bottom of the hot water storage tank 2 from the water supply pipe 5 due to the supply water pressure, and the intermediate temperature hot water in the middle layer of the hot water storage tank 2 is sent to the intermediate temperature hot water hot water supply pipe 52b. To the mixing valve 6e. The control unit 4 mixes the medium temperature hot water from the medium temperature hot water discharge pipe 52b and the water supplied from the pipe 51 branched from the water supply pipe 5 by the mixing valve 6e, and supplies the hot water to the medium temperature hot water outlet (arrows H, N, O). P, O).

  When there is no medium hot water in the hot water storage tank 2, the control unit 4 mixes the hot water and the feed water from the hot water storage tank 2 or the additional tank 21a in the mixing valve 6e and discharges the hot water. When mixing hot water and hot water in the hot water storage tank 2, the control unit 4 switches the switching valve 6 d to the pipe 51 h side and switches the switching valve 6 b to the hot water storage tank 2. When the medium temperature hot water outlet is opened, the hot water at the top of the hot water storage tank 2 is sent to the high temperature hot water hot water piping 52a and the piping 51h via the switching valve 6b by the feed water pressure, and the mixing valve via the switching valve 6d. 6e, mixed with feed water by the mixing valve 6e, and fed to the hot hot water outlet (arrows H, I, J, Q, O. P, O). When mixing the hot water and the feed water in the expansion tank 21a, the control unit 4 switches the switching valve 6d to the piping 51h side, switches the switching valve 6b to the expansion tank 21a side, and discharges the hot water (arrows H, K, L, M, J, Q, O. P, O).

  Further, the control unit 4 is connected to the mixing valve 6e and is disposed in the mixed hot water supply pipe 54 that supplies the mixed hot water to the intermediate temperature outlet, and the temperature sensor 8 that measures the hot water supply temperature of the mixed hot water supply pipe 54 and the electric Are connected to each other, and information on the hot water supply temperature of the mixed hot water supply pipe 54 can be obtained constantly or periodically. Further, the control unit 4 is connected to the memory unit 9, and the memory unit 9 stores a predetermined change value of the hot water supply temperature and a predetermined hot water temperature decrease rate value corresponding to the change value in advance. Has been. The control unit 4 can acquire the change value and the decrease rate value from the memory unit 9 and use them for controlling the mixing valve 6e.

  When the hot water supply temperature of the mixed hot water supply pipe 54 acquired from the temperature sensor 8 is increased by a predetermined change value stored in the memory unit 9, the control unit 4 increases the water mixing ratio of the mixing valve 6e. Control to drive in the direction. Thereafter, the control unit 4 can continue to detect the hot water temperature and calculate the rate of decrease in the hot water temperature.

  For example, when the memory unit 9 stores a value that is a decrease of 0.7 ° C. in 30 ms as the hot water temperature decrease rate corresponding to the case where the hot water supply temperature of the mixed hot water supply pipe 5r is increased by 1 ° C., the temperature When the sensor 8 detects an increase of 1 ° C. in the hot water supply temperature of the mixed hot water supply pipe 5r, the control unit 4 drives the mixing valve 6e in the direction of increasing the mixing ratio of water, and the temperature sensor 8 thereafter. When the hot water temperature decrease rate calculated based on the hot water temperature change detected by the above is 0.7 ms in 30 ms, the driving of the mixing valve 6e is stopped. Thus, in order to return the hot water supply temperature to the original hot water temperature (hot water temperature before rising by 1 ° C.), the mixing valve 6e is driven to increase the mixing ratio of water, but the hot water temperature undershoots. By setting in advance the value of the hot water temperature decrease rate in the memory unit 9, even when the hot water temperature rises due to an unpredictable disturbance, it can be immediately returned to the original hot water temperature, It becomes possible to provide a stable hot water temperature.

  Therefore, it is provided with a temperature sensor 8 that is disposed in the mixed hot water supply pipe 5r and measures the temperature of the mixed hot water, and a control unit 4 that acquires information from the temperature sensor 8 and controls the mixing valve 6e. When the hot water temperature of the mixed hot water rises by a predetermined value, the unit 4 performs control to drive the mixing valve 6e in the direction of increasing the water mixing ratio until the hot water temperature decreases to a predetermined value. When the control for returning the hot water temperature to the original hot water temperature is executed, the driving time of the mixing valve 6e where the hot water temperature does not undershoot can be set in advance. As a result, even if the hot water temperature rises due to an unforeseen disturbance, it can be immediately restored to the original hot water temperature, so that the rise in hot water temperature can be minimized in response to unpredictable disturbance factors. It can be suppressed and a stable hot water temperature can be provided. Further, complicated feedback control and feedforward control are unnecessary, the control unit 4 can be simplified, and the cost can be reduced.

  The present invention is not limited to the configuration of the above embodiment, and various modifications can be made without departing from the spirit of the invention. In the above-described embodiment, an example in which hot water or medium hot water is appropriately fed from the hot water storage tank 2 and mixed with the water from the water supply pipe 5 by the mixing valve 6e to supply the mixed hot water to the mixed hot water outlet is shown. However, the present invention is not particularly limited to this configuration. For example, even in a configuration in which only hot water is supplied from the hot water storage tank 2 and mixed with water from the water supply pipe 5 by the mixing valve 6e, the mixed hot water is supplied. Good.

It is a lineblock diagram of the hot-water supply system which is an embodiment of the invention in this application. It is explanatory drawing of the boiling operation in the hot-water supply system. It is explanatory drawing of the hot water operation in the hot-water supply system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot water supply system 2 Hot water storage tank 3 Heating source 4 Control part 5 Water supply pipe 51b Hot water supply piping 52a High temperature hot water hot water supply piping 52b Medium temperature hot water hot water supply piping 54 Mixed hot water supply piping 6e Mixing valve 8 Temperature sensor

Claims (1)

  A water supply pipe is connected to the bottom, a hot water storage tank for storing water supply and heated hot water, a heating source for heating water sent from the bottom of the hot water storage tank, and hot water heated by connecting the heating source and the hot water storage tank In a hot water supply system comprising a hot water supply pipe for supplying hot water to a hot water storage tank and a hot water supply pipe for discharging hot or medium hot water stored in the hot water storage tank, hot water from the hot water supply pipe and water from the water supply pipe are mixed. Acquires information from the mixing valve, a mixed hot water supply pipe connected to the mixing valve to feed hot water, a temperature sensor installed in the mixed hot water supply pipe to measure the hot water temperature of the mixed hot water, and information from the temperature sensor And a control unit that controls the mixing valve, and when the hot water temperature of the mixed hot water rises to a predetermined value, the control unit mixes the mixing valve with water until the hot water temperature decreases to a predetermined value. Hot water supply characterized by controlling to drive in a direction to increase the ratio Stem.

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