JP5373697B2 - Hot water system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply system capable of preventing decrease in the heat efficiency when hot water is supplied to a tapping plug such as a faucet from a hot water storage tank via a bypass pipe. <P>SOLUTION: The hot water supply system includes: a combustion water heater 3 connected in series to a tapping pipe 17 that leads hot water from a hot water tank 10; a tapping bypass pipe 20, which communicates the tapping pipe 17 to an upstream side and a downstream side of the combustion water heater 3; a bypass valve 21, which opens and closes the tapping bypass pipe 20; a control means 16, 32, which opens the bypass valve 21 when a hot water storage temperature sensor 30 provided in the hot water tank 10 reads a prescribed temperature or higher, and closes the bypass valve 21 when the sensor reads a temperature lower than the prescribed temperature; and a water stop valve 38, which blocks circulation of hot water from the hot water storage tank 10, disposed in the tapping pipe 17 in a side closer to the combustion water heater 3 than the tapping bypass pipe 20. The control means 16, 32 closes the water stop valve 38 when the bypass valve is open and opens the water stop valve 38 when the bypass valve 21 is closed. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a hot water supply system in which an instantaneous heating type combustion water heater is connected in series downstream of a hot water storage tank for storing heated hot water.

  2. Description of the Related Art Conventionally, there is known a hot water supply system in which an instantaneous heating type combustion water heater is connected in series downstream of a hot water storage tank that stores hot water heated by a heat pump (see, for example, Patent Document 1).

  A heat pump is very high in energy efficiency, but has a low heating capacity per unit time, and therefore cannot cope with sudden hot water supply. Therefore, a combustion water heater that operates when the hot water storage tank runs out is connected in series as an auxiliary heat source.

  By connecting a hot water storage tank and a combustion water heater in series, hot water can be supplied at a desired temperature by operating the combustion water heater when the hot water tank runs out of water and avoids running out of hot water. Therefore, since it is not necessary to provide a large-capacity hot water storage tank, the hot water storage tank can be downsized.

JP 2004-125226 A (FIGS. 1 and 2)

  However, in the configuration in which the hot water storage tank and the combustion hot water heater are connected in series as in the conventional hot water supply system, the hot water flow path from the hot water storage tank to the end of the hot water discharge pipe through the combustion hot water heater is relatively long. In addition, a heat exchanger for a combustion water heater and the like exist in the distribution channel.

  Therefore, the pressure loss in the distribution channel becomes large and a sufficient hot water supply flow rate cannot be obtained. In addition, the hot water discharged from the hot water storage tank when the combustion of the combustion water heater is stopped has a disadvantage that the temperature of the hot water is remarkably lowered due to heat radiation when passing through the combustion water heater when the temperature near the combustion water heater is low. is there.

  Therefore, a bypass pipe that bypasses the combustion water heater and communicates the hot water discharge pipe upstream and downstream of the combustion water heater and a bypass valve that opens and closes the bypass pipe are provided, and hot water from the hot water storage tank passes through the bypass pipe. It is conceivable to supply it to outlets such as curans.

  According to this, when the hot water in the hot water storage tank is sufficiently high, the bypass valve is opened and the hot water from the hot water storage tank is circulated to the bypass pipe, thereby reducing the pressure loss and heat dissipation of the hot water due to the circulation through the combustion water heater. Can be reduced.

  However, when the bypass valve is opened and the hot water from the hot water storage tank is discharged from the hot water tap such as a currant, all the hot water from the hot water storage tank flows into the bypass pipe in the hot water pipe connected to the start end of the bypass pipe. Instead, some hot water enters the distribution channel on the combustion water heater side.

  For this reason, even when trying to supply relatively hot water from a hot water storage tank via a bypass pipe to a hot water tap such as a curan, some of the hot water that enters the distribution path on the combustion water heater side becomes a heat loss due to heat dissipation, resulting in thermal efficiency. May decrease.

  In view of the above points, an object of the present invention is to provide a hot water supply system capable of preventing a decrease in thermal efficiency when supplying hot water from a hot water storage tank to a hot water tap such as a curan.

The present invention includes a hot water storage tank, a hot water temperature sensor that detects the temperature of hot water in the hot water storage tank, a heat pump that heats the hot water in the hot water storage tank, a hot water tap in the hot water storage tank, and a hot water tap connected to the end. A hot water supply pipe, a water supply pipe for supplying water to the hot water storage tank, a combustion water heater provided in the middle of the hot water discharge pipe for heating hot water flowing through the hot water discharge pipe with a burner, and the hot water supply pipe for the hot water supply pipe A hot water supply system comprising a hot water bypass pipe that communicates between the upstream side and the downstream side, a bypass valve that opens and closes the hot water bypass pipe, and a control means that opens and closes the bypass valve according to the temperature detected by the hot water storage temperature sensor In the hot water supply pipe, which is closer to the combustion hot water supply than the hot water bypass pipe, a water stop valve is provided to block the flow of hot water from the hot water storage tank to the combustion hot water supply. Serial control unit, said at the opening of the bypass valve is closed the water stop valve, it is opened the water stop valve when the valve is closed the bypass valve, the end of the downstream side of the bypass pipe of the combustion water heater A hot water-filled pipe branched from the hot water pipe between the two and connected to the bathtub is provided .

  According to the present invention, by providing the control means, the hot water in the hot water storage tank is opened when the temperature of the hot water in the hot water storage tank detected by the hot water storage temperature sensor is equal to or higher than a predetermined temperature. Can be supplied from the hot water tap bypassing the combustion water heater, and pressure loss and heat dissipation of hot water due to passing through the combustion water heater can be prevented.

Further, since the control means closes the water stop valve when the bypass valve is opened, it is possible to reliably prevent the hot water in the hot water storage tank from entering the flow path on the combustion hot water supply side. A decrease in thermal efficiency during hot water supply can be prevented.
Furthermore, the temperature detected by the hot water storage temperature sensor is provided even when a hot water pipe connected to the bathtub is branched from the outlet pipe between the downstream side of the combustion water heater and the end of the bypass pipe. When the temperature is lower than the predetermined temperature, the bypass valve is closed and the water stop valve is opened, so that hot water having no temperature difference can be obtained from the end of the hot water supply pipe and the hot water discharge pipe.

In the present invention, furthermore, when provided with a water filling valve for opening and closing the water filling pipe, as the water stop valve, the pressure toward the water filling pipe before to close the water filling valve during water filling completion It is preferable to use a throttle valve that can adjust the flow rate of the hot water supplied to the combustion hot water supply by performing a throttle operation to lower it.

  The throttle valve performs a throttle operation when the hot water filling valve is closed to end the hot water filling operation, thereby reducing the water pressure toward the hot water filling pipe and then closing the hot water filling valve. By doing so, it is possible to prevent the occurrence of an impact sound or the like accompanying the closing of the hot water filling valve. Then, by fully closing the throttle valve as the water stop valve, it is possible to shut off the flow of hot water from the hot water storage tank to the flow path on the combustion hot water supply side without increasing the number of parts (the number of valves). it can.

The block diagram of the hot-water supply system in one Embodiment of this invention. The flowchart which shows the action | operation of the hot-water supply system shown in FIG.

  An embodiment of the present invention will be described with reference to FIG. The hot water supply system of the present embodiment is configured by further connecting an instantaneous heating combustion water heater 3 in series to a tank unit 2 to which a heat pump unit 1 is connected.

The heat pump unit 1 includes a compressor 4, a water heat exchanger (condenser) 5, an expansion valve (decompressor) 6, and an air heat exchanger (evaporator) 7 connected by a refrigerant circulation path 8. It has. The water heat exchanger 5 is connected to a tank circulation path 11 connected to an upper part and a lower part of a hot water storage tank 10 to be described later, and exchanges heat between refrigerant (for example, CO ₂ ) in the refrigerant circulation path 8 and hot water in the tank circulation path 11. By heating, the hot water in the tank circuit 11 is heated.

  The tank circulation path 11 includes a circulation pump 12 for circulating hot water stored in the hot water storage tank 10 to the tank circulation path 11, and a thermistor 13 for detecting the temperature of the hot water flowing from the water heat exchanger 5 to the hot water storage tank 10. A thermistor 14 for detecting the temperature of hot water from the hot water storage tank 10 toward the water heat exchanger 5 is provided.

  In addition, the heat pump unit 1 includes a heat pump controller 15 configured by a microcomputer or the like, and operations of the heat pump 9 and the circulation pump 12 are controlled by a control signal output from the heat pump controller 15.

  The heat pump controller 15 is communicably connected to a tank controller 16 to be described later, and when receiving a heating instruction signal from the tank controller 16, based on the detected temperature of the thermistors 13 and 14 provided in the tank circulation path 11. The circulation pump 12 and the heat pump 9 are operated, and the hot water in the hot water storage tank 10 is heated to a predetermined boiling set temperature (for example, 90 ° C.).

  The tank unit 2 includes a hot water storage tank 10 filled with hot water and a tank controller 16 configured by a microcomputer or the like. A hot water discharge pipe 17 is connected to the upper part of the hot water storage tank 10. The hot water discharge pipe 17 has a start end connected to the hot water storage tank 10 and a terminal end connected to a hot water tap such as a curan (not shown). A water supply pipe 18 is connected to the lower part of the hot water storage tank 10. The water supply pipe 18 has a start end connected to the water supply, a downstream side branched into two, one end connected to the hot water storage tank 10, and the other end connected to the middle of the hot water discharge pipe 17.

  The hot water discharge pipe 17 extends from the downstream of the connection point X with the water supply pipe 18 to the outside of the tank unit 2, passes through a water heater circuit 19 to be described later of the combustion water heater 3, and then extends into the tank unit 2 again. The hot water supply bypass pipe 20 is connected to the inlet side and the outlet side of the hot water heater circuit 19 of the combustion hot water heater 3.

  The hot water bypass pipe 20 is provided with a bypass valve 21. When the bypass valve 21 is closed, hot water from the hot water storage tank 10 flows through the hot water supply circuit 19 of the combustion hot water supply 3, and the bypass valve 21 is opened. When the valve is operated, the hot water from the hot water storage tank 10 flows through the hot water bypass pipe 20 toward the hot water tap such as a caran.

  A hot water thermistor 22 is provided on the upstream side of the connection point X between the hot water pipe 17 and the water supply pipe 18 in the tank unit 2. The water supply pipe 18 is provided with a water amount sensor 23 for detecting the water flow rate and a pressure reducing valve 24 with a check valve. A water supply thermistor 25 is provided in the water supply pipe 18 extending toward the connection point X with the hot water pipe 17.

  The tank unit 2 also includes a hot water variable valve 26 that changes the flow rate of hot water supplied from the hot water storage tank 10 to the hot water discharge pipe 17, and a variable water amount that changes the flow rate of water supplied from the water supply pipe 18 to the hot water discharge pipe 17. A valve 27 is provided.

  Further, a mixing thermistor 28 is provided between a connection point X between the tap water pipe 17 and the feed water pipe 18 provided in the feed water pipe 18 and the upstream end of the tap water bypass pipe 20, and the downstream end of the tap water bypass pipe 20 and the tap water A hot water supply outlet thermistor 29 for detecting the temperature of hot water going to a hot water tap such as a curan is provided on the downstream side of the connection point Y with the pipe 17.

  A hot water storage thermistor 30 (corresponding to the hot water temperature sensor of the present invention) for detecting the temperature of the hot water stored in the hot water storage tank 10 is provided at an upper position of the hot water storage tank 10.

  The tank controller 16 includes a hot water storage thermistor 30, a hot water discharge thermistor 22, a incoming water thermistor 25, a mixing thermistor 28, a hot water supply outlet thermistor 29, and a temperature detected by the thermistor 14 of the tank circulation path 11 and a water supply pipe detected by the water amount sensor 23. The operation of the hot water variable valve 26, the water variable valve 27, and the bypass valve 21 is controlled based on the 18 water flow rate.

  Further, the tank controller 16 has a plurality of operation switches (not shown) such as a temperature switch for setting a desired hot water supply temperature (temperature of hot water supplied from the outlet of the hot water discharge pipe 17) according to a user operation. Is connected to the remote control 31.

  Here, the state of the hot water filled in the hot water storage tank 10 will be described. Since the hot water discharge pipe 17 is connected to the upper part of the hot water storage tank 10 and the water supply pipe 18 is connected to the lower part of the hot water storage tank 10, When 10 hot water is used for hot water supply, the hot water is led out from the hot water discharge pipe 17 and the hot water in the hot water storage tank 10 is reduced, so that water is supplied from the water supply pipe 18 below the hot water storage tank 10. Accordingly, in the hot water storage tank 10, a hot water layer is formed at the top and a water layer is formed at the bottom.

  When the hot water layer at the upper part of the hot water storage tank 10 decreases and the water layer comes to the upper part of the hot water storage tank 10, the temperature detected by the hot water storage thermistor 30 is lower than the set temperature (target hot water temperature) set by the remote controller 31. When this happens, the water will run out. Whether or not the hot water storage tank 10 is in a hot water condition is determined when the detected temperature of the hot water storage thermistor 30 is equal to or lower than the hot water temperature determination temperature (corresponding to the predetermined temperature in the present invention) set near the target hot water supply temperature. The hot water storage tank 10 may be determined to be out of hot water.

  When the detected temperature of the hot water storage thermistor 30 is higher than the target hot water supply temperature (when no hot water has run out), the tank controller 16 detects that the water flow sensor 23 detects water flow exceeding a predetermined lower limit flow rate. 21 is opened, and the opening temperature of the hot water variable valve 26 and the water variable valve 27 is adjusted so that the detected temperature of the mixing thermistor 28 or hot water supply outlet thermistor 29 becomes the target temperature, and the mixing temperature for mixing hot water and water. Execute adjustment control.

  On the other hand, when the detected temperature of the hot water storage thermistor 30 is equal to or lower than the target hot water supply temperature (a state where hot water has run out), when the water amount sensor 23 detects water flow exceeding the lower limit water amount, the tank controller 16 21 is closed. As a result, the hot water in the hot water storage tank 10 flows through the water heater circuit 19 of the combustion water heater 3 and the heating operation by the combustion water heater 3 is performed.

  The combustion water heater 3 may employ a known configuration as an instantaneous heating type. That is, the combustion water heater 3 includes a water heater circuit 19 (which constitutes a part of the hot water discharge pipe 17 in the present invention) connected to the hot water discharge pipe 17 and a hot water supply controller 32 formed of a microcomputer or the like. I have. The water heater controller 32 is communicably connected to the tank controller 16. In the present embodiment, the water heater controller 32 and the tank controller 16 constitute the control means of the present invention.

  The water heater circuit 19 is provided with a heat exchanger 33, a burner 34 that heats the heat exchanger 33, and a hot water supply bypass pipe 35 that bypasses the heat exchanger 33, and a hot water supply bypass pipe in the water heater circuit 19. A hot water filling pipe 36 branched from the water heater circuit 19 and extending to a bathtub (not shown) is connected to the downstream side of the connection point Z of 35.

  The hot water supply circuit 19 includes a bypass servo 37 that changes a distribution ratio between the flow rate of hot water to the heat exchanger 33 and the flow rate of hot water to the hot water supply bypass pipe 35, and hot water supplied to the combustion water heater 3. A water amount servo 38 (corresponding to the water stop valve of the present invention), which is a throttle valve for adjusting the flow rate, is provided.

  Further, the hot water supply circuit 19 detects the flow rate of hot water supplied to the heat exchanger 33 and the hot water supply bypass pipe 35 and the temperature of hot water flowing downstream of the hot water supply bypass pipe 35. A water heater thermistor 40 is provided.

  The hot water filling pipe 36 is provided with a hot water filling flow rate sensor 41 for detecting the flow rate of the hot water filling pipe 36 and a hot water filling valve 42 for opening and closing the hot water filling pipe 36.

  The water heater controller 32 receives a temperature detection signal from the water heater thermistor 40, a water flow rate detection signal from the water heater flow sensor 39, and a water flow rate detection signal from the hot water flow rate sensor 41. . In addition, each operation of the bypass servo 37, the water amount servo 38, the burner 34, and the hot water filling valve 42 is controlled by a control signal output from the water heater controller 32.

  The water heater controller 32 enters a heating permission state when receiving a signal for instructing heating from the tank controller 16. The heating temperature for controlling the combustion amount of the burner 34 so that the detected temperature of the hot water heater thermistor 40 becomes the target hot water temperature when water flow of a predetermined lower limit flow rate is detected by the hot water heater flow sensor 39. Execute adjustment control. Further, when a signal for instructing heating prohibition is received from the tank controller 16, the heating prohibition state is set, and execution of the heating temperature control is prohibited.

  Furthermore, the hot water supply controller 32 opens the hot water filling valve 42 when performing a hot water filling operation for supplying a predetermined amount of hot water to a bathtub (not shown), Accumulate hot water supply.

  When the accumulated value of the hot water supply amount to the bathtub reaches the predetermined amount, the hot water filling valve 42 is closed and the hot water filling operation is terminated. When the hot water filling valve 42 is closed, the water heater controller 32 causes the water amount servo 38 to perform a throttle operation, thereby reducing the water pressure from the hot water heater circuit 19 toward the hot water filling pipe 36, and then closing the hot water filling valve 42. Let By doing so, it is possible to prevent the occurrence of an impact sound or the like accompanying the closing of the hot water filling valve 42.

  Further, the water amount servo 38 can be fully closed as well as the above-described throttling operation, and thereby has a function as a water stop valve that blocks the flow of hot water in the water heater circuit 19. This eliminates the need for a water stop valve in addition to the water amount servo 38 and prevents an increase in the number of parts (the number of valves).

  Here, the operation | movement which concerns on the summary of this invention by the tank controller 16 and the water heater controller 32 which are the control means of this invention is demonstrated with reference to the flowchart of FIG.

  When the power of the tank unit 2 is turned on in STEP 1 of FIG. 2, the process proceeds to STEP 2, and the tank controller 16 fully closes the hot water variable valve 26 and fully opens the water variable valve 27. Then, the tank controller 16 opens the bypass valve 21 in subsequent STEP3.

  In the next STEP 4, the tank controller 16 waits for a water flow state in which water flow exceeding the lower limit flow rate is detected by the water amount sensor 23. In this embodiment, it is determined that the water flow state is established when the amount of water detected by the water amount sensor 23 is 2.7 liters / minute or more. And when it becomes a water flow state, it progresses to STEP5 from STEP4.

  In STEP 5, the tank controller 16 determines whether or not the hot water storage tank 10 is out of hot water when the temperature detected by the hot water storage thermistor 30 is equal to or lower than the set temperature (target hot water supply temperature). When the hot water is out, the process branches to STEP 11, and when the hot water is not out, the process proceeds to STEP 6.

  STEP 6 to STEP 9 are processes when the above-described mixing temperature control is executed.

  In STEP 6, the tank controller 16 opens the bypass valve 21. Next, in STEP 7, a signal for instructing to fully close the water amount servo 38 is transmitted to the water heater controller 32, and further, a signal for prohibiting heating is transmitted to the water heater controller 32 in STEP 8. As a result, the water heater controller 32 shuts off the flow of hot water in the water heater circuit 19 with the water amount servo 38 fully closed, and enters a heating stop state in which the combustion operation of the burner 34 is not performed.

  In subsequent STEP 9, the tank controller 16 adjusts the opening degree of the hot water variable valve 26 and the water variable valve 27, and basically the temperature of the hot water from the end of the hot water discharge pipe 17 (hot water tap such as a currant) is the target hot water supply. Control to reach temperature (mixing temperature control).

  Then, the tank controller 16 determines in STEP 10 whether or not the water amount detected by the water amount sensor 23 is in a water stop state where the water amount is less than the lower limit flow rate (preferably, the water amount set to a value lower than the lower limit flow rate). If the water has stopped, the process returns to STEP 2. If the water has not stopped, the process returns to STEP 5. In the present embodiment, it is determined that the water is stopped when the amount of water detected by the water amount sensor 23 is less than 2.0 liters / minute.

  STEP11 to STEP14 are processes when the above-described heating temperature adjustment control is executed.

  In STEP 11, the tank controller 16 closes the bypass valve 21. Next, in STEP 12, the tank controller 16 transmits a signal for instructing opening of the water amount servo 38 to the water heater controller 32, and further transmits a signal permitting heating to the water heater controller 32 in STEP 13. Thereby, the water heater controller 32 opens the water amount servo 38 and enters the heating permission state. Thereby, all the hot water led out from the hot water storage tank 10 is in a state of flowing through the water heater circuit 19 of the combustion water heater 3.

  In STEP 14, the water heater controller 32 controls the combustion amount of the burner 34 so that the detected temperature of the water heater thermistor 40 becomes the target hot water temperature (heating temperature control).

  Then, it progresses to STEP10 and repeats the process of STEP6-STEP9 or the process of STEP11-STEP14 until it becomes a water stop state.

  As described above, according to the present embodiment, when the hot water storage tank 10 has not run out, the bypass valve 21 of the tank unit 2 is opened and the water amount servo 38 of the combustion water heater 3 is also fully closed. It is possible to reliably prevent the hot water in the hot water storage tank 10 from entering the water heater circuit 19, and it is possible to prevent a decrease in thermal efficiency during hot water supply from the hot water storage tank 10.

  In the present embodiment, the water quantity servo 38 has a function as a water stop valve so that the number of parts can be reduced and cost increase can be prevented. The same effect can be obtained by providing another water stop valve on the upstream side of the water amount servo 38 in the water heater circuit 19 and closing the water stop valve when the bypass valve 21 is opened.

  DESCRIPTION OF SYMBOLS 3 ... Combustion water heater, 9 ... Heat pump, 10 ... Hot water storage tank, 16 ... Tank controller (control means), 17 ... Hot water pipe, 18 ... Hot water supply pipe, 20 ... Hot water bypass pipe, 21 ... Bypass valve, 30 ... Hot water storage thermistor ( (Hot water storage temperature sensor), 32... Water heater controller (control means), 34... Burner, 38.

Claims (2)

A hot water storage tank,
A hot water storage temperature sensor for detecting the temperature of the hot water in the hot water storage tank;
A heat pump for heating the hot water in the hot water storage tank;
A hot water outlet pipe to which hot water from the hot water storage tank is led out and a hot water tap is connected to the end;
A water supply pipe for supplying water to the hot water storage tank;
A combustion water heater that is provided in the middle of the tapping pipe and heats hot water flowing through the tapping pipe with a burner;
A hot water bypass pipe that communicates the hot water pipe between the upstream side and the downstream side of the combustion water heater;
A bypass valve for opening and closing the hot water bypass pipe;
In a hot water supply system comprising: control means for opening the bypass valve when the temperature detected by the hot water storage temperature sensor is equal to or higher than a predetermined temperature and closing the bypass valve when the temperature is lower than the predetermined temperature;
Provided with a water stop valve that shuts off the flow of hot water from the hot water storage tank to the combustion water heater, in the hot water pipe that is closer to the combustion water heater than the hot water bypass pipe,
The control means closes the water stop valve when the bypass valve is opened, opens the water stop valve when the bypass valve is closed ,
A hot water supply system comprising a hot water filling pipe branched from the hot water supply pipe between the downstream side of the combustion water heater and the end of the bypass pipe and connected to a bathtub . The hot water supply system according to claim 1,
Furthermore, a hot water filling valve for opening and closing the hot water filling pipe is provided,
The water stop valve adjusts the flow rate of hot water supplied to the combustion water heater by performing a throttling operation to reduce the water pressure toward the hot water filling pipe prior to closing the hot water filling valve when the hot water filling is completed. A hot water supply system characterized by being a throttle valve.

Images