JP2015025624A - Hot water supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot water supply system capable of supplying hot water at a required temperature with high stability while inhibiting a heating operation of a combustion type hot water heater from being executed.SOLUTION: A tank controller 41 detects the quantity of remaining hot water in a hot water reservoir tank 31 separately for high and low levels when starting supplying hot water from a hot water pipe 32. The detection is executed to change a remaining hot water quantity threshold separating the high and low levels for the quantity of remaining hot water according to the environmental temperature. In the case where the quantity of remaining hot water is at the high level, hot water is supplied via a bypass pipe 34 without executing a heating operation of a combustion type hot water heater 10 until a hot water shortage state. In the case where the quantity of remaining hot water is at the low level, hot water is supplied while executing the heating operation of the combustion type hot water heater 10.

Description

  The present invention relates to a hot water supply system having a hot water storage tank.

  As a hot water supply system having a hot water storage tank for storing hot water heated by a heating device such as a heat pump, a conventional hot water supply system shown in, for example, Patent Document 1 is known.

  This hot water supply system is composed of a hot water pipe led out from the upper part of the hot water storage tank, a hot water pipe connected to the lower part of the hot water storage tank and the middle part of the hot water pipe, and a combustion hot water heater (combustion) arranged downstream of the hot water pipe. A hot water heater that heats water through heat) and a hot water bypass pipe that bypasses the hot water flowing from the intermediate portion of the hot water pipe to the downstream side and flows from the upstream side to the downstream side of the hot water pipe. .

  If there is sufficient remaining hot water above the specified temperature in the hot water storage tank (when the remaining hot water amount is large), the hot water and hot water in the hot water storage tank are not used without the hot water heating operation. Hot water adjusted to a desired temperature by appropriately mixing the water in the pipe is supplied to the hot water outlet at the end of the hot water pipe via the hot water bypass pipe.

  In addition, when the hot water storage tank runs out, the hot water bypass pipe is closed and the entire amount of hot water obtained by appropriately mixing the hot water in the hot water storage tank with the water in the water supply pipe is supplied to the combustion water heater. Then, hot water adjusted to a desired temperature by the heating operation of the combustion type hot water heater is supplied to the hot water outlet at the end of the outlet pipe.

  In addition, when the amount of hot water in the hot water storage tank decreases to a level close to running out of hot water, the heating operation of the combustion hot water heater is started while the hot water bypass pipe is open, and the hot water in the hot water discharge pipe in the combustion hot water heater is increased. I keep it warm.

JP 2011-153776 A

  By the way, in cold districts or in winter, the amount of heat released from the hot water outlet pipes and the like of the hot water supply system is likely to increase in an environment where the temperature around the hot water supply system and the temperature of the water supply are low.

  On the other hand, in the hot water supply system, in order to increase energy efficiency as much as possible, it is desirable to suppress as much as possible the heating operation of the hot water by the combustion hot water heater.

  However, as shown in Patent Document 1, in the conventional hot water supply system, in order to increase energy efficiency, it is particularly preferable to set a small amount of hot water in the hot water storage tank for starting the heating operation of the combustion hot water heater. When the ambient temperature of the system or the temperature of the water supply is low, the temperature of the hot water in the combustion water heater is insufficient before the hot water tank runs out, and immediately after the hot water tank runs out, The present inventors have found that a situation in which cold hot water is temporarily discharged from the hot water outlet of the pipe is likely to occur.

  In order to prevent this, if the amount of hot water remaining in the hot water storage tank for starting the heating operation of the combustion type hot water heater is set to be large, the frequency of the heating operation of the combustion type hot water heater increases, and the energy of the hot water supply system is increased. It tends to cause a decrease in efficiency.

  The present invention has been made in view of such a background, and a hot water supply system capable of realizing hot water supply at a required temperature with high stability while suppressing the heating operation of the combustion hot water heater. The purpose is to provide.

In order to achieve this object, the hot water supply system of the present invention includes a hot water storage tank, heating means for heating the hot water in the hot water storage tank, a hot water outlet pipe led out from the upper part of the hot water storage tank, and a lower part of the hot water storage tank. And a water supply pipe connected to the first intermediate part of the hot water pipe, a combustion hot water heater that is arranged on the downstream side of the first intermediate part of the hot water pipe and heats the hot water flowing through the hot water pipe, and the hot water The hot water flowing downstream from the first middle portion of the pipe flows by bypassing the combustion water heater, and the second middle portion of the outlet pipe on the upstream side of the combustion water heater and the combustion water heater A mixing ratio of a hot water bypass pipe that communicates with the third middle portion of the hot water pipe on the downstream side, hot water supplied from the hot water storage tank to the hot water pipe, and water supplied from the water supply pipe to the hot water pipe. Changing mixing ratio change means , A hot water supply system and a bypass valve that opens and closes the hot water bypass pipe,
An environmental temperature detecting means for detecting an ambient temperature that is an ambient temperature of the hot water system or a hot water temperature of the hot water system;
At the start of hot water supply from the hot water pipe, remaining hot water amount detection means for detecting the amount of hot water that is the amount of hot water of a predetermined temperature or more existing in the hot water storage tank by separating into large and small,
When the remaining hot water amount detecting means detects that the remaining hot water amount is large, heating operation of the combustion type hot water heater is prohibited and the bypass valve is opened until the hot water storage tank becomes hot. In a controlled state, a first hot water supply control process for supplying hot water at a target temperature from the tapping pipe is performed while adjusting the mixing ratio by the mixing ratio changing means, and the remaining hot water amount detecting means is small. Is detected, the operation control means for performing a second hot water supply control process of supplying hot water of the target temperature from the hot water pipe while performing the heating operation of the combustion hot water supply,
The remaining hot water amount detecting means is a remaining value that is a boundary value between a range of the remaining hot water amount from which it is determined that the remaining hot water amount is large and a range of the remaining hot water amount from which it is determined that the remaining hot water amount is small. The hot water amount threshold value is configured to increase as the detected value of the environmental temperature by the environmental temperature detection means decreases, so that the amount of the remaining hot water is detected (first invention). .

  According to the first aspect of the invention, when the remaining hot water amount detecting means detects that the remaining hot water amount is large at the start of hot water supply from the tapping pipe, the operation control means executes the first hot water supply control process. Is done. Thereby, the hot water of the target temperature can be supplied from the hot water pipe without performing the heating operation of the combustion type hot water heater.

  Here, when hot water supply from the hot water supply pipe (and supply of hot water from the hot water storage tank to the hot water supply pipe) continues, the hot water storage tank finally becomes hot. The hot water running out state is a state in which the remaining amount of hot water above a predetermined temperature is zero or close thereto. In this hot water out condition, hot water having a temperature higher than a predetermined temperature cannot be supplied from the hot water storage tank to the tapping pipe. Therefore, in order to supply hot water at the target temperature from the tapping pipe, the first intermediate portion of the tapping pipe is used. Therefore, it is necessary to cause the whole or most of the hot water flowing from the downstream to the downstream side to flow into the combustion type water heater and to perform the heating operation of the combustion type water heater.

  On the other hand, before the hot water storage tank becomes hot, the hot water flowing from the first intermediate part of the hot water pipe to the downstream side (the hot water supplied from the hot water tank to the first intermediate part and the water supply pipe to the first intermediate part. Most of the hot water produced by mixing the supplied water (hereinafter sometimes referred to as mixed hot water) flows through the hot water bypass pipe to the downstream side of the hot water pipe, but part of the mixed hot water is combusted. Flows into the water heater.

  In this case, since the amount of hot water remaining in the hot water storage tank at the start of hot water supply is large, before the hot water storage tank is in a hot water condition, a part of the mixed hot water at the target temperature or a temperature close thereto is added to the combustion hot water heater. It can be supplied over a relatively long time.

  In addition, the remaining hot water amount detecting means increases the remaining hot water amount threshold value as a boundary value for classifying the remaining hot water amount as the detected value of the environmental temperature by the environmental temperature detecting means is lower. Detects the amount of hot water. For this reason, when it is determined that the remaining hot water amount is large by the remaining hot water amount detecting means in a situation where the environmental temperature is relatively low (situation where heat dissipation is likely to occur in the hot water discharge pipe or the like), the hot water storage tank has a predetermined temperature or higher. Sufficient hot water remains.

  For example, when the remaining hot water amount threshold in a situation where the environmental temperature is relatively high is A and the remaining hot water amount threshold in a situation where the environmental temperature is relatively low is B (> A), the environmental temperature is relatively high. In the situation, if the remaining hot water amount is smaller than B but larger than A, the remaining hot water amount detecting means determines that the remaining hot water amount is large.

  On the other hand, in a situation where the environmental temperature is relatively low, if the remaining hot water amount is smaller than B, the remaining hot water amount detection means does not determine that the remaining hot water amount is large, but if the remaining hot water amount is determined to be large. The remaining hot water amount is B or more.

  Therefore, the hot water in the outlet pipe of the combustion water heater is replaced with hot water at a target temperature or close to it with high certainty before the hot water storage tank runs out of water regardless of the environmental temperature. In addition, the temperature of the hot water can be kept warm.

  For this reason, immediately after the hot water storage tank has run out of hot water, it is prevented that water whose temperature rise is insufficient from the combustion type water heater temporarily flows to the downstream side of the hot water discharge pipe.

  Next, when the remaining hot water amount detecting means detects that the remaining hot water amount is small at the start of hot water supply from the hot water pipe, the second hot water supply control process is executed by the operation control means.

  In this case, since the amount of hot water in the hot water storage tank at the start of hot water supply from the hot water outlet pipe is small, the hot water storage tank becomes out of hot water earlier than when the amount of hot water is large. However, even before the hot water storage tank is out of hot water, the heating operation of the combustion hot water heater is performed. For this reason, before the hot water storage tank runs out of hot water, the hot water in the tapping pipe of the combustion type hot water heater can be quickly replaced with hot water having a target temperature or a temperature close thereto to keep the temperature hot.

  In addition, as described above, the remaining hot water amount detecting means detects the amount of the remaining hot water so that the lower the detected value of the environmental temperature by the environmental temperature detecting means, the larger the remaining hot water amount threshold. For this reason, in the situation where the environmental temperature is relatively low, it is determined that the amount of remaining hot water is smaller than the amount of remaining hot water detection means when the amount of remaining hot water is larger than in the situation where the environmental temperature is relatively high. The Rukoto.

  For example, when the remaining hot water amount threshold in a situation where the environmental temperature is relatively high is A and the remaining hot water amount threshold in a situation where the environmental temperature is relatively low is B (> A), the environmental temperature is relatively low. In the situation, not only when the remaining hot water amount is smaller than A but also within the range between A and B, the remaining hot water amount detecting means determines that the remaining hot water amount is small.

  On the other hand, in a situation where the environmental temperature is relatively high, when the remaining hot water amount is a remaining hot water amount in a range between A and B, the remaining hot water amount detecting means determines that the remaining hot water amount is large.

  Therefore, when the environmental temperature is relatively low, before the hot water storage tank becomes out of hot water, a period during which the hot water in the tapping pipe in the combustion type hot water heater can be heated by the heating operation of the combustion type hot water heater. It can be made longer than when the ambient temperature is relatively high. As a result, even if the environmental temperature is relatively low, the hot water in the outlet pipe of the combustion water heater is raised to a target temperature or a temperature close to it with high certainty before the hot water storage tank becomes out of water. In addition, the temperature of the hot water can be kept warm.

  As a result, even when it is detected that the amount of hot water remaining in the hot water storage tank is small at the start of hot water supply from the hot water discharge pipe, immediately after the hot water storage tank becomes hot, regardless of the environmental temperature. It is possible to temporarily prevent insufficiently heated water from flowing from the combustor water heater to the downstream side of the outlet pipe.

  Therefore, according to this invention, it can implement | achieve performing hot water supply of the required temperature with high stability, suppressing performing the heating operation of a combustion type water heater.

  In the first invention, the remaining hot water amount detecting means variably sets the predetermined temperature in accordance with the detected value of the environmental temperature so that the predetermined temperature becomes higher as the environmental temperature is lower, and the setting is performed. It is preferable that the amount of remaining hot water is detected using a predetermined temperature (second invention).

  According to the second aspect of the invention, the predetermined temperature that is the lower limit value of the temperature of the hot water supplied from the hot water storage tank to the outlet pipe during the execution of the first hot water supply control process and the second hot water supply control process is low in the environmental temperature. The higher it gets.

  Therefore, in particular, during the execution of the first hot water supply control process or the second hot water supply control process in a state where the environmental temperature is relatively low, the hot water in the combustion hot water heater is set before the hot water storage tank becomes hot. Replacing the entire hot water of the pipe with hot water having a target temperature or a temperature close thereto, and maintaining the temperature can be stably performed with higher certainty.

  Moreover, in the said 1st invention or 2nd invention, for selecting one operation mode by the predetermined operation of the several operation modes from which the form of the change of the said remaining hot water amount threshold value according to the said environmental temperature differs mutually It is preferable that a mode selection unit is provided, and the remaining hot water amount detection unit is configured to detect the magnitude of the remaining hot water amount in the operation mode selected by the mode selection unit (third invention).

  According to the third aspect of the present invention, the operation mode (and thus the environmental temperature) is adjusted according to the specifications of the hot water supply system, the installation environment (pipe condition of the hot water pipe, the use condition of the heat insulating material, etc.) or the user's preference. The form of the change in the remaining hot water amount threshold according to the above can be selected. As a result, the detection characteristic of the amount of remaining hot water by the said remaining hot water detection means can be made into the characteristic suitable for the specification, installation environment, user preference, etc. of a hot water supply system.

  In the third aspect of the invention, in the plurality of operation modes, when the detected value of the environmental temperature is lower than the predetermined first threshold value, the remaining hot water amount threshold value is larger than when the detected value of the environmental temperature is higher than the first threshold value. The first operation mode in which the remaining hot water amount detecting means detects the amount of the remaining hot water amount, and a predetermined second threshold value at which the detected value of the environmental temperature is set to a temperature higher than the first threshold value. And a second operation mode in which the remaining hot water amount detecting means detects the amount of the remaining hot water amount so that the remaining hot water amount threshold value is larger than the second threshold value when lower than the second threshold value. Preferred (fourth invention).

  According to the fourth aspect of the present invention, in the detection of the remaining hot water amount by the remaining hot water amount detection means, in the first operation mode, when the detected value of the environmental temperature is lower than the first threshold value, the remaining hot water amount threshold is a relative value. When the detected value of the environmental temperature is higher than the first threshold value, the remaining hot water amount threshold value becomes relatively small.

  On the other hand, in the second operation mode, when the detected value of the environmental temperature is lower than the second threshold, the remaining hot water amount threshold is relatively large, and the detected value of the environmental temperature is higher than the second threshold. In this case, the remaining hot water amount threshold value becomes relatively small.

  The second threshold value is set to a temperature higher than the first threshold value.

  For this reason, in the said 2nd operation mode, stability of the temperature control which makes the hot-water supply temperature of the hot water supplied from a tapping pipe track target temperature can be improved rather than a 1st operation mode.

  Further, in the first operation mode, it is possible to suppress the heating operation of the combustion type hot water heater as much as possible in the second operation mode, and to increase the energy efficiency of the hot water supply system as compared to the second operation mode.

  In the fourth aspect of the invention, when the second operation mode is selected by the mode selection unit, the heating unit is configured to store hot water in the hot water storage tank more than when the first operation mode is selected. It is preferable to be configured to heat so that the temperature becomes higher (5th invention).

  According to the fifth aspect of the present invention, in the second operation mode, in addition to improving the stability of controlling the temperature of hot water supplied from the tapping pipe to follow the target temperature, For example, the hot water supply temperature can be quickly controlled to the target temperature.

  In the first to fifth inventions described above, the method of detecting the amount of remaining hot water by the remaining hot water amount detecting means can consequently change the remaining hot water amount threshold as described above according to the detected value of the environmental temperature. What is necessary is just to be comprised.

  For example, the following form is preferably adopted as the form of the detection method. That is, in the first to fifth inventions, the hot water storage tank is provided with a plurality of temperature sensors that respectively detect the temperature of the hot water in the hot water storage tank at a plurality of height positions, The amount of the remaining hot water is detected by comparing the temperature detected by one temperature sensor for detecting the remaining hot water amount selected from the plurality of temperature sensors according to the detected value of the environmental temperature with the predetermined temperature. The temperature sensor at the lower position of the plurality of temperature sensors is selected as the temperature sensor for detecting the remaining hot water amount as the detected value of the environmental temperature is lower. It is preferable (sixth invention).

  According to the sixth aspect of the present invention, the temperature detected by one temperature sensor of the plurality of temperature sensors is compared with the predetermined temperature. As a result, the remaining amount of hot water equal to or higher than the predetermined temperature is obtained. It can be detected by classifying it into large and small. In this case, the remaining hot water amount threshold corresponds to the height position of the temperature sensor.

  Therefore, according to the sixth aspect, the remaining hot water amount threshold value can be easily changed by selectively switching the temperature sensor for detecting the remaining hot water amount in accordance with the detected value of the environmental temperature.

The figure which shows the structure of the hot water supply system of one Embodiment of this invention. The flowchart which shows the action | operation at the time of the hot-water supply operation of the hot-water supply system of FIG. The flowchart which shows the content of the process of STEP13 of FIG. The flowchart which shows the content of the process of STEP14 of FIG.

  An embodiment of the present invention will be described below with reference to FIGS.

  Referring to FIG. 1, the hot water supply system of the present embodiment includes a combustion hot water heater 10, a tank unit 30, and a heat pump unit 60.

  The heat pump unit 60 includes a heat pump 61 as heating means in the present invention. The heat pump 61 includes a compressor 62, a condenser 63, a decompressor 64, and an evaporator 65, and a refrigerant circulation path 66 that circulates the refrigerant through these.

  In this case, the condenser 63 has a function as a heat exchanger that heats the hot water by performing heat exchange between hot water in the hot water storage tank 31 and a refrigerant, which will be described later, and the hot water storage tank 31 and the condenser 63. Is connected to the hot water storage tank 31 via a tank circulation path 67 for circulating hot water between them. The tank circulation path 67 connects the lower and upper parts of the hot water storage tank 31 to the hot water inlet and outlet of the condenser 63, respectively. A circulation pump 68 is interposed in the tank circulation path 67.

  Therefore, by operating the circulation pump 68, hot water in the hot water storage tank 31 is supplied from the lower part of the hot water storage tank 31 to the condenser 63. Then, the hot water returns to the hot water storage tank 31 from the upper part of the hot water storage tank 31 after passing through the condenser 63. Thus, by operating the heat pump 61 while circulating the hot water in the hot water storage tank 31 through the tank circulation path 67, the hot water is cooled in the condenser 63 (the refrigerant heated by the compressor 62). It is heated by heat exchange.

  In FIG. 1, the circulation pump 68 is interposed in the flow path from the lower part of the hot water storage tank 31 to the condenser 63, but is interposed in the flow path from the condenser 63 to the upper part of the hot water storage tank 31. May be.

  The heat pump unit 60 further includes a heat pump controller 71 having a function of performing operation control of the heat pump 61 and the circulation pump 68. The heat pump controller 71 is composed of an electronic circuit unit including a microcomputer or the like, and can communicate with a tank controller 41 described later.

  The tank circulation path 67 includes a temperature sensor 72 that detects the temperature of hot water supplied from the condenser 63 to the hot water storage tank 31 and a temperature sensor that detects the temperature of hot water supplied from the hot water storage tank 31 to the condenser 63. 73 is attached.

  The heat pump controller 71 includes a hot water boiling instruction to heat the hot water in the hot water storage tank 31 from a tank controller 41, which will be described later, and a basic operation mode (or a hot water storage defined by the basic operation mode, which will be described later) of the hot water supply system. The data indicating the boiling temperature is input, and the detection data of the temperature sensors 72 and 73 are input.

  When the heat pump controller 71 receives the hot water boiling command from the tank controller 41, the heat pump controller 71 controls the operation of the heat pump 61 and the circulation pump 68 so as to heat the hot water in the hot water storage tank 31.

  In this case, the heat pump controller 71 uses a temperature detected by the temperature sensors 72 and 73 to execute a predetermined control program, whereby the temperature of the hot water in the hot water storage tank 31 is set according to the basic operation mode of the hot water supply system. The output of the heat pump 61 and the rotation speed of the circulation pump 68 (and thus the flow rate of the hot water flowing through the tank circulation path 67) are controlled so as to raise the temperature to a prescribed prescribed hot water boiling temperature.

  Although details will be described later, in the present embodiment, the basic operation mode includes two types of operation modes, a standard mode and a temperature control priority mode. The hot water boiling temperature in the temperature control priority mode is set to a predetermined temperature higher than the hot water boiling temperature in the standard mode. For example, the hot water boiling temperature in the standard mode is 45 ° C., and the hot water boiling temperature in the temperature control priority mode is 50 ° C.

  Next, the tank unit 30 includes a hot water storage tank 31 that stores hot water heated by the heat pump 61, a hot water discharge pipe 32, a water supply pipe 33, and a hot water bypass pipe 34.

  The hot water discharge pipe 32 is a flow path for supplying hot water to a hot water outlet arranged in a kitchen, a washroom, a bathroom, or the like. The hot water discharge pipe 32 is led out from the upper part of the hot water storage tank 31 and is routed through the combustion hot water heater 10 (specifically, a heat exchanger 13 described later) to reach the final hot water outlet. For example, a currant 35 is connected to the hot water supply port at the end of the hot water discharge pipe 32.

  Note that the hot water outlet at the end of the hot water outlet pipe 32 may be branched into a plurality, and a shower or the like may be connected instead of the currant 35.

  The water supply pipe 33 is a flow path for supplying water supplied from a water pipe or the like to the hot water storage tank 31 and the hot water discharge pipe 32. The water supply pipe 33 is branched from a middle portion 33x on the downstream side thereof into a first branch water supply pipe 33a and a second branch water supply pipe 33b. The first branch water supply pipe 33 a is connected to the lower part of the hot water storage tank 31, and the second branch water supply pipe 33 b is connected (joined) to the first intermediate portion 32 x on the upstream side of the hot water discharge pipe 32.

  Accordingly, the water supply pipe 33 supplies water to the hot water storage tank 31 from the lower portion thereof via the first branch water supply pipe 33a and supplies water to the first intermediate portion 32x of the hot water discharge pipe 32 via the second branch water supply pipe 33b. It is configured. A pressure reducing valve 36 is interposed at a location upstream of the midway portion 33x of the water supply pipe 33.

  In other words, the first intermediate portion 32x of the hot water discharge pipe 32 is supplied with hot water supplied from the hot water storage tank 31 to the hot water discharge pipe 32 as water is supplied from the water supply pipe 33 to the hot water storage tank 31 via the first branch water supply pipe 33a. And the water supplied from the water supply pipe 33 to the hot water discharge pipe 32 through the second branch water supply pipe 33b.

  Then, a flow rate adjustment for adjusting a tank hot water flow rate that is a flow rate of hot water supplied from the hot water storage tank 31 to the hot water discharge pipe 32 (flow rate of hot water flowing into the first intermediate portion 32x of the hot water discharge pipe 32 from the hot water storage tank 31 side). A valve 37 is interposed in the hot water discharge pipe 32 between the hot water storage tank 31 and the first intermediate part 32x. In addition, a flow rate adjustment valve 38 for adjusting the mixed feed water flow rate that is the flow rate of water supplied from the feed water pipe 33 to the first intermediate portion 32x of the hot water discharge pipe 32 through the second branch feed water pipe 33b is provided in the second branch feed water. It is interposed in the pipe 33b.

  These flow rate adjusting valves 37 and 38 adjust the tank hot water flow rate and the mixed water supply flow rate, respectively, so that hot water supplied from the hot water storage tank 31 to the hot water discharge pipe 32 and the water supply pipe 33 are routed through the second branch water supply pipe 33b. It is possible to change the mixing ratio with water supplied to the hot water discharge pipe 32 (specifically, the ratio between the tank hot water flow rate and the mixed feed water flow rate). Therefore, in this embodiment, the flow rate adjusting valves 37 and 38 constitute the mixing ratio changing means in the present invention.

  Instead of providing the flow rate adjusting valves 37 and 38 as described above, for example, a three-way valve may be interposed in the first intermediate portion 32x of the hot water discharge pipe 32, and the mixing ratio changing means may be constituted by the three-way valve.

  The hot water bypass pipe 34 bypasses the hot water flowing from the first intermediate portion 32x of the hot water pipe 32 to the downstream side (hereinafter referred to as mixed hot water) from the upstream side to the downstream side of the combustion hot water heater 10 and flows (combustion hot water supply). The flow path for flowing without going through the vessel 10).

  The hot water bypass pipe 34 communicates the second intermediate portion 32 y of the hot water discharge pipe 32 on the upstream side of the combustion type hot water heater 10 and the third intermediate portion 32 z of the hot water discharge pipe 32 on the downstream side of the combustion hot water heater 10. It is piped. The second intermediate part 32y is an intermediate part on the downstream side of the first intermediate part 32x.

  The hot water bypass pipe 34 is provided with a bypass valve 39 that opens and closes the hot water bypass pipe 34.

  Here, the hot water bypass pipe 34 is more than the flow path on the combustion hot water heater 10 side of the hot water discharge pipe 32 (the flow path from the second intermediate portion 32y to the third intermediate portion 32z via the combustion hot water heater 10). The flow path has a small pressure loss.

  For this reason, in a state where the bypass valve 39 is opened, most of the mixed hot water flowing downstream from the first intermediate portion 32x of the outlet pipe 32 passes through the outlet hot bypass pipe 34 from the second intermediate portion 32y. It flows downstream, and the remaining part of the mixed hot water flows into the combustion type water heater 10.

  When the bypass valve 39 is closed, the entire mixed hot water flows into the combustion hot water heater 10.

  The tank unit 30 further includes a tank controller 41 having a function of performing operation control of the flow rate adjusting valves 37 and 38 and the bypass valve 39. The tank controller 41 is composed of an electronic circuit unit including a microcomputer or the like, and can communicate with the heat pump controller 71 and a hot water supply controller 21 described later.

  Further, the tank controller 41 has a mode setting switch 42 for instructing the tank controller 41 of a basic operation mode (standard mode or temperature control priority mode) of the hot water supply system, and for the user to operate the hot water supply system. Remote control 43 and environmental temperature sensor 44 for detecting the ambient temperature of the hot water supply system as the environmental temperature are connected.

  The mode setting switch 42 is a switch for selectively setting one of the basic operation mode of the standard mode and the temperature control priority mode by a contractor operating at the time of installation or maintenance of the hot water supply system. It is. The mode setting switch 42 corresponds to mode selection means in the present invention.

  Here, the standard mode is an operation mode in which the hot water supply operation of the hot water supply system 1 (the operation of supplying hot water to the hot water inlet) can be performed with better energy efficiency than the temperature control priority mode. Even in an environment, this is an operation mode in which the stability of the follow-up control to the target temperature of the hot water supply temperature (the temperature of hot water discharged from the hot water outlet) during the hot water supply operation can be improved compared to the standard mode.

  The basic operation mode is set according to the installation environment of the hot water supply system, the user's preference, and the like. For example, when the hot water supply system is installed in a place where the temperature is not so low, or when the user places importance on energy efficiency, the standard mode is set as the basic operation mode. When the hot water supply system is installed at a low temperature such as in a cold region, or when emphasizing the controllability (temperature control performance) of the hot water temperature, the temperature control priority mode is set as the basic operation mode. The

  The standard mode and the temperature control priority mode correspond to the first operation mode and the second operation mode in the present invention, respectively.

  The remote controller 43 tanks operation information such as on / off of the hot water supply operation of the hot water supply system, on / off of the hot water operation of the bathtub, the target hot water temperature, the target hot water temperature, etc., according to the operation of an operation switch (not shown) or voice input. This is a terminal device that instructs the controller 41.

  Instead of the mode setting switch 42, the basic operation mode may be selected by a predetermined operation of the operation switch of the remote controller 43 (simultaneous operation of a plurality of operation switches, etc.). In this case, the remote controller 43 functions as mode selection means.

  The environmental temperature sensor 44 corresponds to the environmental temperature detection means in the present invention. The environmental temperature sensor 44 detects the outside air temperature as the environmental temperature, and inputs the detected data to the tank controller 41.

  Various sensors described below are assembled in the hot water storage tank 31, the hot water discharge pipe 32, and the water supply pipe 33 of the tank unit 30, and detection data of these sensors are also input to the tank controller 41.

  That is, the hot water storage tank 31 includes a first tank temperature sensor 45 and a second tank temperature sensor 46 for separating and detecting a remaining hot water amount that is an amount of hot water having a predetermined temperature or higher existing in the hot water storage tank 31; A third tank temperature sensor for detecting the hot water condition of the hot water storage tank 31 (the state in which there is no or almost no hot water in the hot water storage tank 31) and the temperature of the hot water in the hot water storage tank 31. 47 is attached.

  The first to third tank temperature sensors 45, 46, 47 are mounted on the outer peripheral surface or inside of the hot water storage tank 31 at different predetermined height positions of the hot water storage tank 31, respectively. The temperature of hot water in the hot water storage tank 31 is detected.

  In this case, each height (height from the lower end of the hot water storage tank 31) h1, h2, h3 of the first to third tank temperature sensors 45, 46, 47 is h1 <h2 <h3 as shown in the figure. It is set to be.

  More specifically, the height h1 of the first tank temperature sensor 45 is such that the capacity (hereinafter referred to as the first predetermined amount) in the hot water storage tank 31 above the height h1 is 30 liters, for example. The height h2 of the temperature sensor 46 is 12 liters in capacity (hereinafter referred to as a second predetermined amount) in the hot water storage tank 31 above the height h2, and the height h3 of the third tank temperature sensor 47 is H1, h2, and h3 are set so that the capacity in the hot water storage tank 31 above the height h3 (hereinafter referred to as a third predetermined amount) is, for example, 6 liters.

  Further, a flow rate sensor that detects a flow rate of water flowing through the water supply pipe 33 (total water supply flow rate to the hot water storage tank 31 and the hot water discharge pipe 32) at a location upstream of the midway portion 33x in the water supply pipe 33. 49 is attached, and a temperature sensor 50 for detecting the water supply temperature is attached to the second branch water supply pipe 33b.

  Further, at a location upstream of the first intermediate part 32x of the hot water discharge pipe 32, a flow rate sensor 51 for detecting the tank hot water flow rate and a temperature of hot water flowing into the first intermediate part 32x from the hot water storage tank 31 side are detected. A temperature sensor 52 is mounted.

  Further, a temperature sensor 53 for detecting the temperature of the mixed hot water flowing downstream from the first intermediate part 32x is mounted at a location between the first intermediate part 32x and the second intermediate part 32y of the hot water discharge pipe 32, A temperature sensor 54 for detecting the temperature of hot water discharged from the hot water supply port (hot water supply temperature) is mounted at a location downstream of the middle part 32z.

  The temperature sensor 50 for detecting the feed water temperature may be attached to the feed pipe 33 upstream of the midway portion 33x or the first branch feed pipe 33a. Further, instead of either one of the flow sensors 49 and 51, a flow sensor for detecting the flow rate of the water flowing through the second branch water supply pipe 33b may be attached to the second branch water supply pipe 33b.

  The tank controller 41 executes a predetermined control program using the basic operation mode set by the mode setting switch 42, the driving operation information given from the remote controller 43, and the detection data of the sensors 44 to 54.

  In this case, the tank controller 41 has a function of performing control related to the heat pump unit 60 in cooperation with the heat pump controller 71 as a function realized by executing the control program. In this control, the tank controller 41 monitors the detected temperature of, for example, the third tank temperature sensor 47 among the first to third tank temperature sensors 45 to 47, and the detected temperature is set in advance to the hot water boiling start temperature. When it becomes below, the said hot water boiling command is output to the heat pump controller 71. The hot water boiling start temperature is lower than the boiling temperature.

  Moreover, the tank controller 41 has a function as a remaining hot water detection means in the present invention. Furthermore, the tank controller 41 has a function as an operation control means in the present invention by cooperating with the hot water supply controller 21.

  The function of the tank controller 41 as the remaining hot water amount detection means and the function as the operation control means will be schematically described below.

  First, regarding the function as the remaining hot water amount detecting means, in this embodiment, the tank controller 41, based on the temperature detected by the first tank temperature sensor 45 or the second tank temperature sensor 46, The remaining amount of hot water is detected by separating it into large and small. In the following description, unless otherwise specified, the “remaining hot water amount” means the amount of hot water at a predetermined temperature or higher.

  Here, when the hot water in the hot water storage tank 31 is heated and water is supplied from the first branch water supply pipe 33a of the water supply pipe 33 to the hot water storage tank 31, the hot water in the hot water storage tank 31 is heated along with the water supply. Hot water is supplied from the upper part of the hot water storage tank 31 to the hot water discharge pipe 32. Along with this, a low temperature water layer is basically generated in the lower part of the hot water storage tank 31 and a high temperature hot water layer is generated in the upper part. As the water supply to the hot water storage tank 31 proceeds, the lower temperature layer in the lower part of the hot water storage tank 31 increases and the higher temperature layer in the upper part decreases.

  For this reason, the state in which the detected temperature of the first tank temperature sensor 45 is higher than the predetermined temperature indicates that the remaining hot water amount in the hot water storage tank 31 is larger than the first predetermined amount, and the detected temperature is lower than the predetermined temperature. The state indicates that the amount of remaining hot water is less than the first predetermined amount.

  Therefore, by comparing the detected temperature of the first tank temperature sensor 45 with a predetermined temperature, the amount of remaining hot water in the hot water storage tank 31 is classified into large and small (specifically, whether it is larger than the first predetermined amount). It will be possible.

  Similarly, by comparing the temperature detected by the second tank temperature sensor 46 with a predetermined temperature, the amount of remaining hot water in the hot water storage tank 31 is divided into large and small (specifically, whether the amount is larger than the second predetermined amount). Can be detected.

  Accordingly, in the present embodiment, the tank controller 41 compares the detected temperature of the first tank temperature sensor 45 or the second tank temperature sensor 46 with a predetermined temperature, and detects the remaining hot water amount in the hot water storage tank 31 by dividing it into large and small. .

  In this case, the tank controller 41 selectively switches the temperature sensor 45 or 46 used for detecting the amount of remaining hot water according to the temperature detected by the environmental temperature sensor 44 (outside air temperature). More specifically, the tank controller 41 selects the first tank temperature sensor 45 in order to detect the amount of remaining hot water when the detected temperature (outside air temperature) of the environmental temperature sensor 44 is lower than a predetermined value. When the temperature detected by the temperature sensor 44 is higher than a predetermined value, the second tank temperature sensor 46 is selected.

  When the first tank temperature sensor 45 is selected, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is small when the temperature detected by the first tank temperature sensor 45 is equal to or lower than a predetermined temperature. When the detected temperature is higher than the predetermined temperature, it is determined that the remaining hot water amount in the hot water storage tank 31 is large. In this case, the remaining hot water amount threshold value (a boundary value between the large remaining hot water amount range and the small remaining hot water amount range) for classifying the amount of remaining hot water in the hot water storage tank 31 is consequently the first predetermined amount. It becomes.

  In addition, when the second tank temperature sensor 46 is selected, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is small when the temperature detected by the second tank temperature sensor 46 is equal to or lower than a predetermined temperature. When the detected temperature is higher than the predetermined temperature, it is determined that the remaining hot water amount in the hot water storage tank 31 is large. In this case, the remaining hot water amount threshold value for classifying the amount of remaining hot water in the hot water storage tank 31 results in the second predetermined amount (<first predetermined amount).

  Therefore, when the temperature detected by the environmental temperature sensor 44 is lower than the predetermined value, the remaining hot water amount threshold value is larger than when the temperature is higher than the predetermined value.

  In this embodiment, the predetermined temperature to be compared with the first tank temperature sensor 45 or the second tank temperature sensor 46 is determined according to the basic operation mode of the hot water supply system and the target hot water supply temperature during the hot water supply operation.

  Supplementally, by comparing the temperature detected by the third tank temperature sensor 47 with a predetermined temperature, the amount of remaining hot water in the hot water storage tank 31 is divided into large and small (specifically, whether the amount is larger than the third predetermined amount). It can also be detected.

  However, in the present embodiment, the state in which the remaining hot water amount in the hot water storage tank 31 is smaller than the third predetermined amount is a state in which there is no hot water having a predetermined temperature or higher in the hot water storage tank 31 or almost no hot water in the hot water storage tank 31. It means that the hot water has run out.

  Therefore, in the present embodiment, the tank controller 41 uses the third tank temperature sensor 47 as a sensor for detecting the occurrence of a hot water out condition in the hot water storage tank 31.

  The third tank temperature sensor 47 is connected to the upper part of the hot water storage tank 31 (first tank) due to some abnormality or the like even though the temperature detected by the first tank temperature sensor 45 or the second tank temperature sensor 46 is equal to or higher than a predetermined temperature. It is also used as a sensor for detecting an irregular state in which cold water having a temperature lower than a predetermined temperature is present in the upper part of the temperature sensor 45 and the second tank temperature sensor 46).

  Next, regarding the function of the tank controller 41 as the operation control means, the tank controller 41 performs a hot water supply operation of the hot water supply system (more specifically, a hot water supply operation in which water flow exceeding a predetermined lower limit flow rate is detected by the flow sensor 49). In a situation where it is determined at the start that the amount of remaining hot water in the hot water storage tank 31 is large based on the temperature detected by the first tank temperature sensor 45 or the second tank temperature sensor 46, the first hot water supply control process is executed.

  Although details will be described later, in the first hot water supply control process, the tank controller 41 controls the flow rates detected by the flow sensors 49 and 51 and the temperature sensors 50, 52, 53, while the bypass valve 39 is controlled to be opened. The detected temperature (detected value of the hot water supply temperature) of the temperature sensor 54 (or 53) is the target temperature (here, the target hot water temperature set by the remote control 43) while monitoring the detected temperature of 54. A mixing temperature control process that is a process for controlling the opening degree of the flow rate adjusting valves 37 and 38 (and thus adjusting the mixing ratio) is executed. Further, the tank controller 41 instructs the hot water supply controller 21 to prohibit the heating operation of the combustion type water heater 10.

  Thereafter, when the hot water storage tank 31 is detected to be out of the hot water based on the temperature detected by the third tank temperature sensor 47, the tank controller 41 closes the bypass valve 39 and the combustion hot water heater 10 The hot water controller 21 is commanded to permit the heating operation.

  In the situation where the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is small based on the temperature detected by the first tank temperature sensor 45 or the second tank temperature sensor 46 at the start of the hot water supply operation of the hot water supply system. The tank controller 41 cooperates with the hot water supply controller 21 to execute the second hot water supply control process.

  Although details will be described later, in the second hot water supply control process, the tank controller 41 executes the mixed temperature control process while the bypass valve 39 is controlled to be closed. Further, the tank controller 41 instructs the hot water supply controller 21 to permit the heating operation of the combustion hot water heater 10.

  When the remote controller 43 instructs the hot water operation of the bathtub, the tank controller 41 instructs the hot water supply controller 21 to perform the hot water operation of the bathtub and closes the bypass valve 39. Control to the state.

  Furthermore, the tank controller 41 detects the flow rate detected by the flow rate sensors 49 and 51 and the temperature sensors 50 and 52 in a situation where the hot water storage tank 31 has not been detected based on the temperature detected by the third tank temperature sensor 47. , 53 is monitored, and the mixed temperature control process is executed so that the detected temperature of the temperature sensor 53 becomes the target temperature (here, the target hot water temperature set by the remote controller 43).

  In this case, the detection of the hot water condition is performed by comparing the temperature detected by the third tank temperature sensor 47 with the target hot water temperature.

  Then, when the hot water storage tank 31 is out of the hot water state, the hot water supply controller 21 is instructed to perform the heating operation of the combustion hot water heater 10.

  Next, the combustion type hot water heater 10 appropriately heats hot water supplied from the upstream side by the hot water discharge pipe 32 by the combustion type heating source 11. This combustion heating source 11 includes a burner 12 such as a gas burner, and a heat exchanger 13 to which combustion heat of the burner 12 is applied. And the hot water supply pipe 32 introduced into the combustion type water heater 10 causes the hot water supplied from the upstream second intermediate portion 32y to flow to the downstream third intermediate portion 32z via the heat exchanger 13. So that it is piped.

  The combustion type water heater 10 further includes a bypass pipe 14 for bypassing the heat exchanger 13 from the upstream side to the downstream side of the heat exchanger 13 and flowing hot water, and a bathtub (not shown) from the downstream side of the heat exchanger 13. And a hot water pipe 15 for supplying hot water for hot water.

  The bypass pipe 14 connects the middle part on the upstream side and the middle part on the downstream side of the heat exchanger 13 in the hot water pipe 32 inside the combustion type water heater 10. And in the hot water pipe 32 inside the combustion type water heater 10, the flow rate of hot water flowing from the connection point to the heat exchanger 13 and the bypass pipe are connected to the connection point with the bypass pipe 14 on the upstream side of the heat exchanger 13. A bypass servo valve 16 for adjusting a bypass ratio, which is a ratio to the flow rate of the hot water flowing in 14, is interposed.

  Further, the hot water supply pipe 32 inside the combustion type water heater 10 has a water amount servo valve 17 for adjusting the flow rate of hot water flowing into the combustion type water heater 10 from the upstream side at a location upstream of the bypass servo valve 16. Is intervening. Further, a check valve 18 for preventing a back flow of hot water from the downstream side of the combustion hot water heater 10 is interposed in the hot water discharge pipe 32 at a location downstream of the heat exchanger 13.

  The hot water pipe 15 is branched from the hot water discharge pipe 32 on the downstream side of the heat exchanger 13 and is connected to reach a bathtub (not shown). The hot water pipe 15 is provided with a hot water valve 19 that opens and closes the hot water pipe 15.

  The combustion type water heater 10 further includes a hot water supply controller 21 having a function of performing the combustion operation of the burner 12 or the operation control of the bypass servo valve 16, the water amount servo valve 17 and the hot water valve 19. The hot water controller 21 is constituted by an electronic circuit unit including a microcomputer or the like.

  Further, the hot water supply pipe 32 inside the combustion type water heater 10 has a flow rate sensor 22 for detecting the entire flow rate of the hot water supplied from the upstream side to the combustion type water heater 10 on the upstream side of the bypass servo valve 16; A temperature sensor 23 for detecting the temperature of the hot water supplied to the downstream side from the connection point with the bypass pipe 14 on the downstream side of the heat exchanger 13 (the hot water supply hot water temperature) is mounted on the downstream side of the connection point. . Further, the hot water pipe 15 is provided with a flow rate sensor 24 for detecting the flow rate of hot water supplied to the bathtub through the hot water pipe 15.

  The hot water supply controller 21 receives an instruction from the tank controller 41 that a hot water supply operation or a hot water beam operation should be performed, data indicating a target hot water temperature or a target hot water temperature, a heating operation of the combustion hot water heater 10 during the hot water operation (more details) In addition, a command indicating whether or not to permit hot water heating by the combustion type heating source 11 is input, and detection data of the flow sensors 22 and 24 and the temperature sensor 23 are input.

  The hot water supply controller 21 is instructed to perform a hot water supply operation, and in a state where the heating operation of the combustion hot water heater 10 is permitted, the flow rate sensor 22 allows water flow exceeding a predetermined lower limit flow rate. When detected, the heating temperature is a process for controlling the combustion amount of the burner 12 and the bypass ratio by the bypass servo valve 16 so that the temperature detected by the temperature sensor 23 becomes the target temperature (here, the target hot water supply temperature). Execute key control processing.

  In addition, the hot water supply controller 21 opens the hot water valve 19 in a state where it is instructed to perform the hot water operation. And when the heating operation of the combustion type water heater 10 is instructed from the tank controller 41, the hot water controller 21 performs heating so that the temperature detected by the temperature sensor 23 becomes the target temperature (here, the target hot water beam temperature). The temperature control process is executed. During the hot water operation, when the integrated value of the flow rate detected by the flow sensor 24 reaches the target hot water amount set by the remote controller 43 or the like, the hot water valve 19 is closed and the combustion water heater 10 is turned on. The heating operation is terminated.

  In the present embodiment, the above-described tank controller 41 and hot water supply controller 21 constitute the operation control means in the present invention.

  Next, the control processing of the tank controller 41 and the hot water supply controller 21 during the hot water supply operation of the hot water supply system of the present embodiment will be described in detail with reference to FIGS.

  In a state where the power supply of the hot water supply system is turned on, the tank controller 41 monitors the presence or absence of water flow through the water supply pipe 33 (water flow to the hot water supply port due to opening of the currant 35, etc.) in STEP 1 (STEP 1). .

  In this case, the tank controller 41 detects water flow when the detected flow rate of the flow rate sensor 49 of the water supply pipe 33 is equal to or higher than a preset lower limit flow rate. In addition, in the water stop state in which the water supply pipe 33 is not passing water, the tank controller 41 controls the bypass valve 39 of the hot water bypass pipe 34 to the open state.

  When water flow is detected in STEP 1, the control process from STEP 2 is executed by the tank controller 41 and the hot water supply controller 21.

  In addition, the control processing from STEP2 described below is stopped when the water stop state is reached in which the water flow through the water supply pipe 33 is not detected.

  The tank controller 41 first performs the processing of STEPs 2 to 12 by the function as the remaining hot water amount detection means.

  In STEP2, the tank controller 41 determines whether the basic operation mode set by the mode setting switch 42 is the standard mode or the temperature adjustment priority mode.

  When the basic operation mode is set to the standard mode, the tank controller 41 determines that the current outside air temperature (environment temperature) detected by the environment temperature sensor 44 is greater than the preset first threshold value in STEP 3. Determine if it is high. The first threshold is, for example, 10 ° C.

  Then, the tank controller 41 selects one of the first tank temperature sensor 45 and the second tank temperature sensor 46 as a temperature sensor for detecting the remaining hot water amount according to the determination result of STEP 3 (STEP 4, 6). Further, the tank controller 41 detects the amount of remaining hot water in the hot water storage tank 31 using the selected temperature sensor 45 or 46 (STEPs 5 and 7).

  Specifically, when the detected value of the outside air temperature is higher than the first threshold value (10 ° C.), the tank controller 41 selects the second tank temperature sensor 46 as a temperature sensor for detecting the remaining hot water amount in STEP 4. To do. In STEP 5, the tank controller 41 basically determines the amount of remaining hot water in the hot water storage tank 31 by comparing the detected temperature th2 of the second tank temperature sensor 46 with a predetermined temperature for detecting the remaining hot water amount. To do.

  When the basic operation mode of the hot water supply system is the standard mode, the tank controller 41 uses the target hot water supply temperature set by the remote controller 43 as the predetermined temperature for detecting the remaining hot water amount. In STEP 5, basically, when th2 ≦ target hot water supply temperature, it is determined that the remaining hot water amount is small, and when th2> target hot water supply temperature, it is determined that the remaining hot water amount is large. .

  Here, when th2> target hot water supply temperature, the temperature of hot water in the hot water storage tank 31 at a position higher than the second tank temperature sensor 46 is usually higher than the target hot water supply temperature. However, although the frequency of occurrence is low, there is a case where low-temperature hot water below the target hot-water supply temperature exists above the hot water storage tank 31. In such a case, low-temperature hot water is temporarily supplied from the hot water storage tank 31 to the hot water discharge pipe 32.

  Therefore, in the present embodiment, the tank controller 41 determines that the detected temperature th3 of the third tank temperature sensor 47 disposed at the upper part in the hot water storage tank 31 is a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature) in STEP5. Also when it is below, it judges that the amount of remaining hot water is small (it is considered that the amount of remaining hot water is small).

  Then, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is large when both th2 and th3 are higher than a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature).

  Further, when the detected value of the outside air temperature is a low temperature equal to or lower than the first threshold (10 ° C.) in STEP 3, the tank controller 41 sets the first tank temperature sensor 45 as a temperature sensor for detecting the remaining hot water amount in STEP 6. Choose as. Then, in STEP 7, the tank controller 41 basically compares the detected temperature th1 of the first tank temperature sensor 45 with the target hot water supply temperature as a predetermined temperature for detecting the remaining hot water amount, whereby the remaining temperature of the hot water storage tank 31 is increased. Judge the amount of hot water.

  In this case, in STEP 7, basically, when th1 ≦ target hot water supply temperature, it is determined that the remaining hot water amount is small, and when th1> target hot water supply temperature, it is determined that the remaining hot water amount is large. The

  However, in the present embodiment, for the same reason as in STEP5, the tank controller 41 causes the detected temperature th3 of the third tank temperature sensor 47 to be equal to or lower than a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature) in STEP7. Even if it is, it is determined that the amount of remaining hot water is small (the amount of remaining hot water is considered small).

  Then, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is large when both th1 and th3 are higher than a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature).

  In the following description, a situation in which th1 or th2 is higher than a predetermined temperature for detecting the remaining hot water amount and th3 is equal to or lower than a predetermined temperature for detecting the remaining hot water amount is referred to as “an irregular state of the temperature in the tank”.

  The processes in STEP 3 to STEP 7 described above are processes for detecting the amount of remaining hot water in the hot water storage tank 31 by the function as the remaining hot water amount detecting means of the tank controller 41 in the standard mode.

  In this case, in a situation where the detected value of the outside air temperature (environment temperature) is higher than the first threshold (10 ° C.), the second tank temperature sensor 46 is used as a temperature sensor for detecting the remaining hot water amount, while the outside air temperature is In a situation where the detected value of (environment temperature) is lower than the first threshold (10 ° C.) (low temperature environment situation), the temperature sensor for detecting the remaining hot water amount is the first lower position than the second tank temperature sensor 46. A tank temperature sensor 45 is used.

  In STEP 5, the remaining hot water amount threshold corresponding to the predetermined temperature for detecting the remaining hot water amount is a second predetermined amount corresponding to the height position of the second tank temperature sensor 46 except for an irregular state of the tank internal temperature.

  Further, in STEP 7, the remaining hot water amount threshold value corresponding to the predetermined temperature for detecting the remaining hot water amount is the first predetermined amount (> the first predetermined amount) corresponding to the height position of the first tank temperature sensor 45 except for the irregular situation of the tank internal temperature. 2 predetermined amount).

  Therefore, in STEP 5 or 7, as a result, the remaining hot water amount threshold value is higher than the first threshold value in a situation where the detected value of the outside air temperature (environment temperature) is higher than the first threshold value (10 ° C.). The lower situation becomes bigger.

  For this reason, in the situation where the detected value of the outside air temperature is lower than the first threshold value, it is determined that the remaining hot water amount is small earlier than in the case where the detected value is higher than the first threshold value.

  If it is determined in STEP 5 or 7 that the remaining hot water amount in the hot water storage tank 31 is large, the first hot water supply control process is executed by the tank controller 41 in STEP 13. The first hot water supply control process is a control process for performing hot water supply to the hot water supply port in a state where the heating operation of the combustion hot water heater 10 is prohibited.

  When it is determined in STEP 5 or 7 that the remaining hot water amount in the hot water storage tank 31 is small, the second hot water supply control process is executed in STEP 14 by the cooperation of the tank controller 41 and the hot water controller 21. The second hot water supply control process is a control process for supplying hot water to the hot water supply port in a state where the heating operation of the combustion hot water heater 10 is permitted.

  The first hot water supply control process is executed as shown in the flowchart of FIG.

  In STEP 21, the tank controller 41 gives a command for prohibiting the heating operation of the combustion type water heater 10 to the hot water controller 21.

  Further, in STEP 22, the tank controller 41 controls the bypass valve 39 of the hot water bypass pipe 34 to be opened. Thereby, most of the mixed hot water flowing downstream from the first intermediate portion 32x of the hot water discharge pipe 32 is supplied to the hot water supply port through the hot water bypass pipe 34. Further, a part of the mixed hot water flows into the combustion type hot water heater 10 without passing through the hot water bypass pipe 34. Thereby, the hot water in the tapping pipe 32 in the combustion type water heater 10 is replaced with the mixed hot water (hot water) flowing into the combustion type water heater 10.

  And the tank controller 41 performs the above-mentioned mixing temperature control process in STEP23. In other words, the tank controller 41 adjusts the mixing ratio, which is the ratio of the tank discharge flow rate and the mixed feed water flow rate, via the flow rate adjusting valves 37 and 38, so that the hot water supply temperature detected by the temperature sensor 54 (or 53) is adjusted. Temperature control is performed so that the target hot water temperature is reached.

  During the execution of the mixed temperature control process, the heating operation of the combustion type water heater 10 is not performed, and the burner 12 of the combustion type heating source 11 is maintained in a fire extinguishing state.

  The tank controller 41 performs the mixed temperature control process and compares the detected temperature th3 of the third tank temperature sensor 47 with a predetermined hot water judgment temperature in STEP 24, thereby generating the hot water out condition of the hot water storage tank 31. The presence or absence of is detected.

  In this case, the target hot water supply temperature is used as the hot water runout determination temperature. When th3> target hot water supply temperature, the tank controller 41 determines that the hot water out condition has not occurred, and when th3 ≦ target hot water supply temperature, the tank controller 41 determines that the hot water out condition has occurred.

  When the occurrence of a hot water out condition is not detected in STEP 24, the tank controller 41 continues the processing in STEPs 21 to 24. When the occurrence of the hot water out condition is detected in STEP 24, the tank controller 41 ends the first hot water supply control process and starts the second hot water supply control process described later.

  The above is the first hot water supply control process. In this case, the hot water in the hot water storage tank 31 stored by the heat pump 61 having relatively high energy efficiency is used, and the hot water supply to the hot water supply port (hot water at the target hot water temperature is not performed). Therefore, the hot water supply can be performed with good energy efficiency.

  Next, the second hot water supply control process is executed as shown in the flowchart of FIG.

  In STEP 31, the tank controller 41 detects whether or not the hot water storage tank 31 has run out as in the case of STEP 24.

  When the occurrence of the hot water out condition is not detected in STEP 31, the tank controller 41 gives a command to permit the heating operation of the combustion type water heater 10 to the hot water supply controller 21 in STEP 32.

  Further, in STEP 33, the tank controller 41 controls the bypass valve 39 of the hot water bypass pipe 34 to be closed. Therefore, in this case, unlike the case of the first hot water supply control process, the bypass valve 39 is controlled to be closed with the heating operation of the combustion hot water heater 10 permitted.

  And in STEP34, the heating temperature control process by the hot water supply controller 21 is performed. At the same time, the mixing ratio is also adjusted by the tank controller 41.

  Specifically, in STEP 34, the tank controller 41 sets the mixing ratio so that the temperature of the mixed hot water detected by the temperature sensor 53 becomes a predetermined mixing target temperature that is lower than the target hot water supply temperature by a minimum capacity temperature. Adjustment is performed via the flow rate adjusting valves 37 and 38. The minimum capacity temperature is obtained by heating the hot water of the current amount of water (flow rate detected by the flow sensor 22) flowing into the combustion type water heater 10 through the hot water discharge pipe 32 through the heat exchanger 13 with the minimum combustion amount of the burner 12. In this case, the temperature of the hot water rises.

  Further, in STEP 34, the hot water controller 21 determines the combustion amount of the burner 12 and the bypass ratio by the bypass servo valve 16 so that the temperature detected by the temperature sensor 23 (the temperature of hot water flowing out from the combustion hot water heater 10) becomes the target hot water temperature. Are controlled (heating temperature control processing is executed). Note that only the combustion amount of the burner 12 may be controlled with a constant bypass ratio.

  The processes in STEPs 32 to 34 described above are continued until it is detected in STEP 31 that the hot water storage tank 31 has run out of hot water.

  Supplementally, in STEP 34, the heating operation of the combustion water heater 10 may be performed with the bypass valve 39 opened. In STEP 34, the opening degree of the flow rate adjusting valves 37, 38, and thus the mixing ratio may be kept constant.

  When the occurrence of a hot water outage condition in the hot water storage tank 31 is detected in STEP 31 or when the occurrence of a hot water outage condition is detected in STEP 24 of the first hot water supply control process, the tank controller 41 in step 35 The controller 21 is given a command to permit the heating operation of the combustion water heater 10.

  Further, in STEP 36, the tank controller 41 controls the bypass valve 39 of the hot water bypass pipe 34 to be closed. As a result, the entire amount of the mixed hot water flowing downstream from the first intermediate portion 32 x of the hot water discharge pipe 32 is supplied to the combustion hot water heater 10.

  And in STEP37, the heating temperature control process by the hot water supply controller 21 is performed. In this case, when the amount of remaining hot water in the hot water storage tank 31 becomes zero, the temperature of the hot water detected by the temperature sensor 53 cannot be controlled to a desired target temperature. Therefore, in STEP 37, the flow rate adjusting valves 37, 38 are controlled so as to reduce the passage resistance of the hot water discharge pipe 32 and the second branch water supply pipe 33b, for example, by fully opening the flow rate adjusting valves 37, 38.

  After the hot water storage tank 31 runs out of hot water, the processes in STEPs 35 to 37 described above are continued.

  The above is the control processing of the tank controller 41 and the hot water supply controller 21 during the hot water supply operation of the hot water supply system in the standard mode.

  Next, a control process when the temperature adjustment priority mode is set as the basic operation mode of the hot water supply system will be described.

  When the basic operation mode set in STEP 2 is the temperature control priority mode, the tank controller 41 sets the current outside air temperature (environment temperature) detected by the environment temperature sensor 44 in STEP 8 in advance. It is determined whether it is higher than the set second threshold value. In this case, the second threshold is set to a temperature higher than the first threshold (10 ° C.) in the standard mode, for example, 20 ° C.

  Then, the tank controller 41 selects one of the first tank temperature sensor 45 and the second tank temperature sensor 46 as a temperature sensor for detecting the remaining hot water amount according to the determination result of STEP 8 (STEP 9, 11). Further, the tank controller 41 detects the amount of remaining hot water in the hot water storage tank 31 using the selected temperature sensor 45 or 46 (STEPs 10 and 12).

  Specifically, when the detected value of the outside air temperature is higher than the second threshold value (20 ° C.), the tank controller 41 selects the second tank temperature sensor 46 as a temperature sensor for detecting the remaining hot water amount in STEP 9. To do. In STEP 10, the tank controller 41 basically determines the amount of remaining hot water in the hot water storage tank 31 by comparing the detected temperature th2 of the second tank temperature sensor 46 with a predetermined temperature for detecting the remaining hot water amount. To do.

  Here, when the basic operation mode of the hot water supply system is the temperature control priority mode, in the present embodiment, a temperature slightly higher than that in the standard mode is used as the predetermined temperature for detecting the remaining hot water amount. That is, in the present embodiment, a temperature obtained by adding a predetermined value α to the target hot water temperature set by the remote controller 43 is used as the predetermined temperature for detecting the remaining hot water amount in the temperature control priority mode. The predetermined value α is 3 ° C., for example.

  In STEP 10, basically, when th2 ≦ target hot water supply temperature + α, it is determined that the remaining hot water amount is small, and when th2> target hot water supply temperature + α, it is determined that the remaining hot water amount is large. Is done.

  However, in the present embodiment, in the same manner as in STEP5, the irregular condition of the tank internal temperature is taken into consideration, and the tank controller 41 determines that the detected temperature th3 of the third tank temperature sensor 47 is the predetermined temperature for detecting the remaining hot water amount in STEP10. Also when it is below (target hot water supply temperature + α), it is determined that the remaining hot water amount is small (the remaining hot water amount is considered small).

  Then, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is large when both th1 and th3 are higher than a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature + α).

  Further, when the detected value of the outside air temperature is a low temperature equal to or lower than the second threshold value (20 ° C.) in STEP 8, the tank controller 41 sets the first tank temperature sensor 45 as a temperature sensor for detecting the remaining hot water amount in STEP 11. Choose as. In STEP 12, the tank controller 41 basically compares the detected temperature th1 of the first tank temperature sensor 45 with a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature + α). Determine the amount of remaining hot water.

  In this case, in STEP12, basically, when th1 ≦ target hot water supply temperature + α, it is determined that the remaining hot water amount is small, and when th1> target hot water supply temperature + α, the remaining hot water amount is large. To be judged.

  However, in this embodiment, the irregular state of the tank internal temperature is taken into consideration as in STEP 5, and the tank controller 41 determines that the detected temperature th 3 of the third tank temperature sensor 47 is the predetermined temperature for detecting the remaining hot water amount in STEP 12. Also when it is below (target hot water supply temperature + α), it is determined that the remaining hot water amount is small (the remaining hot water amount is considered small).

  Then, the tank controller 41 determines that the remaining hot water amount in the hot water storage tank 31 is large when both th1 and th3 are higher than a predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature + α).

  Supplementally, since the occurrence frequency of the irregular state of the tank internal temperature is generally sufficiently low, it is omitted in STEPs 10 and 12 to compare the detected temperature th3 of the third tank temperature sensor 47 with the predetermined temperature for detecting the remaining hot water amount. May be. This also applies to STEPs 5 and 7 in the standard mode described above.

  The processes in STEP 8 to STEP 12 are processes for detecting the amount of remaining hot water in the hot water storage tank 31 by the function as the remaining hot water amount detecting means of the tank controller 41 in the temperature control priority mode.

  In this case, in a situation where the detected value of the outside air temperature (environment temperature) is higher than the second threshold value (20 ° C.), the second tank temperature sensor 46 is used as a temperature sensor for detecting the remaining hot water amount, while the outside air temperature. In a situation where the detected value of (environment temperature) is lower than the second threshold (20 ° C.) (low temperature environment situation), the temperature sensor for detecting the remaining hot water amount is the first lower position than the second tank temperature sensor 46. A tank temperature sensor 45 is used.

  In this case, since the second threshold value is higher than the first threshold value in the standard mode, in the temperature adjustment priority mode, not only the case where the outside air temperature is lower than the first threshold value but also a temperature slightly higher than the first threshold value (first The temperature of the first tank temperature sensor 45 is used as a temperature sensor for detecting the remaining hot water amount even when the temperature is between the threshold value and the second threshold value.

  In STEP 10, the remaining hot water amount threshold corresponding to the predetermined temperature for detecting the remaining hot water amount, and in STEP 12, the remaining hot water amount threshold corresponding to the predetermined temperature for detecting the remaining hot water amount, respectively, except for the irregular state of the tank internal temperature, respectively. , Second predetermined amount, first predetermined amount (> second predetermined amount).

  Therefore, in STEP 10 or 12, as a result, the remaining hot water amount threshold value is higher than the second threshold value in a situation where the detected value of the outside air temperature (environment temperature) is higher than the second threshold value (20 ° C.). The lower situation becomes bigger.

  For this reason, in the situation where the detected value of the outside air temperature is lower than the second threshold value, it is determined that the remaining hot water amount is small earlier than in the case where it is higher than the second threshold value. Furthermore, when the temperature control priority mode is compared with the standard mode, in the situation where the outside air temperature is between the first threshold value and the second threshold value, the temperature control priority mode is earlier than the standard mode. Therefore, it is determined that the remaining hot water amount is small.

  Moreover, since the predetermined temperature (target hot water supply temperature + α) for detecting the remaining hot water amount in the temperature control priority mode is higher than the predetermined temperature (target hot water temperature) for detecting the remaining hot water amount in the standard mode, in STEP 10 in the temperature control priority mode, When the detection result of the remaining hot water amount is switched from large to small, the amount of heat that the remaining hot water (second predetermined amount of remaining hot water) existing above the height position of the second tank temperature sensor 46 basically has When the detection result of the remaining hot water amount is switched from large to small in STEP 5 in the standard mode, the amount of heat of the remaining hot water existing above the height position of the second tank temperature sensor 46 is increased.

  If it is determined in STEP 10 or 12 that the amount of remaining hot water in the hot water storage tank 31 is large, the first hot water supply control process described above is executed in STEP 13.

  If it is determined in STEP 10 or 12 that the amount of remaining hot water in the hot water storage tank 31 is small, the second hot water supply control process described above is executed in STEP 14.

  The above is the control processing of the tank controller 41 and the hot water supply controller 21 during the hot water supply operation of the hot water supply system in the temperature control priority mode.

  According to the hot water supply system of the present embodiment described above, during the hot water supply operation, the tank controller 41 first changes the remaining hot water amount threshold for classifying the remaining hot water amount according to the environmental temperature (outside air temperature). The amount of remaining hot water in the hot water storage tank 31 is detected. When it is determined that the remaining hot water amount is large, the first hot water supply control process is executed by the tank controller 41. When it is determined that the remaining hot water amount is small, the second hot water supply control process is performed by the tank controller 41. And the hot water supply controller 21 cooperates.

  Here, since the bypass valve 39 is opened until the hot water storage tank 31 becomes hot, the mixed hot water supplied downstream from the first intermediate portion 32x of the hot water discharge pipe 32 is large. The portion flows downstream through the hot water bypass pipe 34. Then, only a part of the mixed hot water is supplied to the combustion hot water heater 10.

  For this reason, especially when environmental temperature is low, the hot water in the tapping pipe 32 of the combustion type water heater 10 is easily cooled by heat radiation.

  However, in this embodiment, when the detected value of the environmental temperature is a low temperature lower than the first threshold value or the second threshold value at the start of the hot water supply operation, the detected value of the environmental temperature is higher than when the detected value is high. The magnitude of the remaining hot water amount is detected by increasing the remaining hot water amount threshold value for classifying the remaining hot water quantity.

  For this reason, when the first hot water supply control process is performed when it is determined that the amount of remaining hot water is large, the hot water storage tank 31 is not required to perform the heating operation of the combustion hot water heater 10 even when the environmental temperature is low. Before the hot water runs out, a part of the mixed hot water is sufficiently supplied to the combustion hot water heater 10, and the entire hot water in the outlet pipe 32 of the combustion hot water heater 10 is changed to a target hot water temperature or hot water having a temperature close thereto. The temperature of the hot water can be kept warm.

  In addition, when the second hot water supply control process is performed when it is determined that the remaining hot water amount is small, the mixed hot water that can be supplied to the combustion hot water heater 10 before the hot water storage tank 31 is in a hot water condition is small. The heating operation of the hot water heater 10 is performed.

  Moreover, by detecting the amount of remaining hot water according to the environmental temperature, when the environmental temperature is low, it is determined that the remaining hot water amount is small in a state where the remaining hot water amount is larger than when the environmental temperature is high, and the combustion type water heater 10 A second hot water supply control process for performing the heating operation is executed. For this reason, when the environmental temperature is low, basically, the heating operation of the combustion-type hot water heater 10 is performed for a longer period of time until the hot water storage tank 31 is in a hot water state.

  Accordingly, when the second hot water supply control process is performed when it is determined that the remaining hot water amount is small, the heating of the combustion hot water heater 10 is performed before the hot water storage tank 31 becomes hot even if the environmental temperature is low. By operation, the entire hot water of the outlet pipe 32 of the combustion type hot water heater 10 can be quickly heated to the hot water temperature at or near the target hot water temperature, and the temperature of the hot water can be kept warm.

  As a result, regardless of whether the amount of remaining hot water at the start of the hot water supply operation is large or small, all the amount of hot water is supplied to the combustion-type water heater 10 in response to the hot water storage tank 31 being out of hot water. When starting to supply hot water via the valve (closing the bypass valve 39), the hot water temporarily cooled from the combustion water heater 10 is supplied to the hot water outlet of the outlet pipe 32, This can be prevented regardless of the temperature. Therefore, the stability of the follow-up control of the actual hot water temperature to the target hot water temperature can be enhanced regardless of the environmental temperature.

  In the present embodiment, any one of the basic operation mode can be selected from the standard mode and the temperature adjustment priority mode. In this case, in the temperature control priority mode, the second threshold value (20 ° C.) of the environmental temperature (outside air temperature) used for switching the temperature sensor 45 or 46 for detecting the remaining hot water amount (and thus switching the remaining hot water amount threshold value), The temperature is set higher than the first threshold value (10 ° C.) in the standard mode.

  For this reason, in particular, when the environmental temperature is in the range between the first threshold value and the second threshold value, in the temperature control priority mode, the stability of the follow-up control of the actual hot water temperature to the target hot water temperature is improved. This can be further enhanced than the standard mode.

  In addition, in the temperature control priority mode, the predetermined temperature for detecting the remaining hot water amount (target hot water supply temperature + α) is set higher than the predetermined temperature for detecting the remaining hot water amount in the standard mode (target hot water supply temperature). For this reason, in the temperature control priority mode, the 2 hot water supply control process is basically performed earlier than the standard mode. As a result, the stability of the follow-up control can be improved as compared with the standard mode, particularly when the environmental temperature is low.

  Therefore, in the temperature control priority mode, it is possible to realize good stability of the follow-up control regardless of the environmental temperature.

  In the temperature control priority mode, the hot water boiling temperature of the heat pump 61 is higher than the hot water boiling temperature in the standard mode. For this reason, in the temperature control priority mode, it is possible to supply hot water having a temperature higher than that in the standard mode to the hot water discharge pipe 32 before the hot water storage tank 31 is in a hot water condition. As a result, when the hot water supply operation is started, the actual hot water supply temperature can be quickly controlled to the target hot water supply temperature.

  As described above, in the temperature control priority mode, it is possible to improve the stability or responsiveness of the follow-up control of the actual hot water temperature to the target hot water temperature.

  On the other hand, in the standard mode, although the stability of the follow-up control of the actual hot water temperature to the target hot water temperature is lower than the temperature control priority mode, the heating operation of the combustion water heater 10 is performed more than the temperature control priority mode. Is suppressed, and the energy efficiency of the hot water supply system can be made high.

  Next, modifications of the embodiment described above will be described.

  In the embodiment, the predetermined temperature for detecting the remaining hot water amount may be changed according to the detected value of the environmental temperature (outside air temperature) in both the standard mode and the temperature control priority mode. Specifically, the lower the detected value of the environmental temperature, the higher the predetermined temperature for detecting the remaining hot water amount.

  For example, in the standard mode, the predetermined temperature for detecting the remaining hot water amount is set as the target hot water supply temperature + β, and this β is set to increase as the detected value of the environmental temperature decreases.

  Similarly, in the temperature control priority mode, the predetermined temperature for detecting the remaining hot water amount is set as the target hot water supply temperature + α + β, and this β is set so as to increase as the detected value of the environmental temperature decreases.

  In this way, in both the standard mode and the temperature control priority mode, the stability of the follow-up control of the actual hot water temperature to the target hot water temperature can be further enhanced regardless of the environmental temperature.

  In the embodiment, the predetermined temperature for detecting the remaining hot water amount in the standard mode and the predetermined temperature for detecting the remaining hot water amount in the temperature control priority mode may be set to the same temperature.

  In the above embodiment, the ambient temperature that is the ambient temperature of the hot water supply system is detected as the environmental temperature. However, the detected environmental temperature is the hot water storage tank 31, the hot water discharge pipe 32, or the combustion-type hot water heater 10. As long as the temperature is substantially the same as the ambient temperature, the outside air temperature may not be required.

  Furthermore, instead of the ambient temperature of the hot water supply system, the feed water temperature is detected as the environmental temperature, and the remaining hot water amount threshold value is changed according to the detected value of the feed water temperature (for example, the detected value of the feed water temperature by the temperature sensor 50). You may do it.

  For example, in STEP 3 or 8 of FIG. 2, whether the detected value of the feed water temperature is higher than a predetermined threshold (threshold value for each operation mode) instead of comparing the detected value of the outside air temperature with the first threshold value or the second threshold value. It may be determined whether or not, and the temperature sensor for detecting the remaining hot water amount may be selectively switched according to the determination result, similarly to the embodiment.

  Furthermore, both the outside air temperature (temperature around the hot water supply system) and the water supply temperature may be detected, and the remaining hot water amount threshold value may be changed according to the detected values of both temperatures. For example, in STEP 3 or 8 of FIG. 2, it is determined whether both the detected value of the outside air temperature and the detected value of the feed water temperature are higher than a predetermined threshold set corresponding to each of the detected values. Accordingly, the temperature sensor for detecting the remaining hot water amount may be selectively switched as in the above embodiment.

  In the above embodiment, the temperature sensor 45 or 45 for detecting the remaining hot water amount is switched depending on whether the environmental temperature is higher or lower than the threshold value (first threshold value or second threshold value). However, the remaining hot water amount threshold value may be switched to three or more types according to the environmental temperature.

  For example, three or more temperature sensors for detecting the remaining hot water amount are provided at different height positions of the hot water storage tank 31, and one temperature sensor for detecting the remaining hot water amount is selected according to the detected value of the environmental temperature. In this case, the environmental temperature is classified into three or more types such as high, medium and low, and a temperature sensor at a lower position is selected as the environmental temperature is lower.

  By doing in this way, a remaining hot water amount threshold value can be switched to 3 or more types according to environmental temperature.

  In the above embodiment, the temperature sensors 45 and 46 attached to the hot water storage tank 31 are used to detect the amount of remaining hot water. It is.

  That is, the flow rate of hot water (hot water of a predetermined temperature or higher) flowing from the hot water storage tank 31 to the hot water discharge pipe 32 from the boiling state of the hot water storage tank 31 (full state of remaining hot water) is detected by an appropriate flow sensor, and the detected value is obtained. Accumulate. Then, the remaining amount of hot water in the hot water storage tank 31 is estimated by subtracting the integrated value of the detected value of the flow rate from the capacity of the hot water storage tank 31. By comparing the estimated value of the remaining hot water amount with a remaining hot water amount threshold value set according to the environmental temperature, the magnitude of the remaining hot water amount can be detected.

  Moreover, in the said embodiment, although it comprised so that a standard mode and a temperature control priority mode could be selected as a basic operation mode of a hot-water supply system, three or more types from which the form of change of the remaining hot water amount threshold according to environmental temperature mutually differs The operation mode may be selected. Alternatively, the operation mode of the hot water supply system may be only one operation mode (for example, the standard mode or the temperature control priority mode).

  Moreover, in the said embodiment, although the hot-water supply system which can perform hot water supply of a bathtub was demonstrated, the hot-water supply system of this invention may perform only a hot-water supply driving | operation. Alternatively, a hot water supply system capable of performing hot water heating in addition to the hot water supply operation may be used.

  DESCRIPTION OF SYMBOLS 10 ... Combustion type water heater, 21 ... Hot water controller (operation control means), 31 ... Hot water storage tank, 32 ... Hot water pipe, 32x ... First intermediate part, 32y ... Second intermediate part, 32z ... Third intermediate part, 33 ... Water supply pipe, 34 ... Hot water bypass pipe, 37, 38 ... Flow rate adjusting valve (mixing ratio changing means), 41 ... Tank controller (residual hot water amount detecting means, operation control means), 42 ... Mode setting switch (mode selecting means), 44 ... environmental temperature sensor (environment temperature detection means), 45, 46 ... temperature sensor, 61 ... heat pump (heating means).

Claims (6)

A hot water storage tank, heating means for heating hot water in the hot water storage tank, a hot water pipe led out from an upper part of the hot water storage tank, a water supply pipe connected to a lower part of the hot water storage tank and a first middle part of the hot water discharge pipe And a combustion type water heater that is disposed on the downstream side of the first middle portion of the tapping pipe and that heats the hot water flowing through the tapping pipe, and the hot water that flows downstream from the first middle portion of the tapping pipe, The second middle part of the tapping pipe on the upstream side of the combustion type water heater and the third middle part of the tapping pipe on the downstream side of the combustion type water heater are communicated so as to bypass the combustion type water heater and flow. A hot water bypass pipe, a mixing ratio changing means for changing a mixing ratio of hot water supplied from the hot water storage tank to the hot water pipe and water supplied from the water supply pipe to the hot water pipe, and opening and closing the hot water bypass pipe With bypass valve A hot water system,
An environmental temperature detecting means for detecting an ambient temperature that is an ambient temperature of the hot water system or a hot water temperature of the hot water system;
At the start of hot water supply from the hot water pipe, remaining hot water amount detection means for detecting the amount of hot water that is the amount of hot water of a predetermined temperature or more existing in the hot water storage tank by separating into large and small,
When the remaining hot water amount detecting means detects that the remaining hot water amount is large, heating operation of the combustion type hot water heater is prohibited and the bypass valve is opened until the hot water storage tank becomes hot. In a controlled state, a first hot water supply control process for supplying hot water at a target temperature from the tapping pipe is performed while adjusting the mixing ratio by the mixing ratio changing means, and the remaining hot water amount detecting means is small. Is detected, the operation control means for performing a second hot water supply control process of supplying hot water of the target temperature from the hot water pipe while performing the heating operation of the combustion hot water supply,
The remaining hot water amount detecting means is a remaining value that is a boundary value between a range of the remaining hot water amount from which it is determined that the remaining hot water amount is large and a range of the remaining hot water amount from which it is determined that the remaining hot water amount is small. A hot water supply system configured to detect the magnitude of the remaining hot water amount so that the hot water amount threshold value increases as the detected value of the environmental temperature by the environmental temperature detection means decreases. The hot water supply system according to claim 1,
The remaining hot water amount detecting means variably sets the predetermined temperature according to the detected value of the environmental temperature so that the predetermined temperature becomes higher as the environmental temperature is lower, and the predetermined temperature is used to set the predetermined temperature. A hot water supply system configured to detect the amount of remaining hot water. In the hot water supply system according to claim 1 or 2,
A mode selection means for selecting one operation mode among a plurality of operation modes having different forms of change of the remaining hot water amount threshold according to the environmental temperature by a predetermined operation;
The hot water supply system, wherein the remaining hot water amount detecting means is configured to detect the amount of the remaining hot water amount in the operation mode selected by the mode selecting means. In the hot water supply system according to claim 3,
In the plurality of operation modes, when the detected value of the environmental temperature is lower than a predetermined first threshold, the remaining hot water amount threshold is set larger than when the detected value of the environmental temperature is higher than the first threshold. A first operation mode in which the detection means detects the amount of the remaining hot water, and the detection value of the environmental temperature is lower than a predetermined second threshold set at a temperature higher than the first threshold. A hot water supply system comprising: a second operation mode in which the remaining hot water amount detection means detects the amount of the remaining hot water amount so that the remaining hot water amount threshold value is larger than when the remaining threshold value is higher than two threshold values. The hot water supply system according to claim 4,
When the second operation mode is selected by the mode selection means, the heating means sets the temperature of the hot water in the hot water storage tank to a higher temperature than when the first operation mode is selected. A hot water supply system configured to be heated so as to become. In the hot water supply system according to any one of claims 1 to 5,
A plurality of temperature sensors that respectively detect the temperature of hot water in the hot water storage tank at a plurality of height positions of the hot water storage tank;
The remaining hot water amount detecting means compares the temperature detected by one temperature sensor for detecting the remaining hot water amount selected from the plurality of temperature sensors according to the detected value of the environmental temperature with the predetermined temperature, It is configured to detect the amount of the remaining hot water, and the lower the detected value of the environmental temperature, the lower the temperature sensor among the plurality of temperature sensors is selected as the temperature sensor for detecting the remaining hot water amount. A hot water supply system characterized by being configured to do so.

Images