JP5068599B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus including a plurality of heat source machines.

  Equipped with a heat pump refrigeration cycle that passes the refrigerant discharged from the compressor through the water heat exchanger, decompressor, and outdoor heat exchanger to the compressor and allows the water heat exchanger to function as a condenser, and supplies water to the sealed tank In addition, there is a hot water supply device that stores hot water in a tank by circulating water in the tank through a water heat exchanger using a pump (for example, Patent Document 1).

In such a hot water supply device, a heat source comprising a heat pump refrigeration cycle having the water heat exchanger and a water cycle in which water is circulated through the water heat exchanger so that it can be used in facilities with a large amount of hot water used. Some machines have been installed so that the number of operating heat source machines can be controlled.
JP 2005-308250 A

  In the case of a hot water supply apparatus having a plurality of heat source units, it is important to always store hot water at a necessary temperature in a tank.

  The present invention takes the above circumstances into consideration, and its purpose is to always store hot water at a required temperature in a tank, and thereby to provide an excellent reliability capable of constantly supplying hot water to a hot water supply load. Is to provide a hot water supply device.

The hot water supply device of the invention according to claim 1, water is fed into sealed tank, and hot water by heating water in the sealed tank with the heat source equipment, stored temporarily and the hot water to the sealed tank, the The hot water in the closed tank is supplied to and stored in the open tank, the flow rate adjusting valve provided in the flow path of the hot water from the closed tank to the open tank, and the hot water in the closed tank A temperature sensor for detecting the temperature of the hot water, a control means for controlling the opening degree of the flow rate adjusting valve according to the temperature detected by the temperature sensor, and a water level detection means for detecting the water level in the open tank. . The control means includes first control means for controlling the number of operating heat source units and the opening of the flow rate adjusting valve according to the temperature detected by the temperature sensor, and the water level detected by the water level detecting means is nearly full. The second control means for reducing the number of operating heat source units regardless of the control of the first control means, and when the detected water level of the water level detection means reaches full water, Third control means for stopping the operation of each heat source unit regardless of the control, and when the detected water level of the water level detection means has not reached full water, the detection temperature of the temperature sensor is predetermined when the operation of each heat source unit is stopped. A fourth control means for maintaining the flow rate adjusting valve in an open state until a state less than the value continues for a certain period of time, guiding hot water in the sealed tank to the open tank, and then fully closing the flow rate adjusting valve; Have.

  According to the hot water supply apparatus of the present invention, hot water having a necessary temperature can be always stored in the tank. Thereby, the stable hot water supply to the hot water supply load is always possible, and the reliability can be improved.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a plurality of heat source devices 1 are connected in parallel between a water supply side main pipe 2 and a hot water supply side main pipe 3, and the water supply side main pipe 2 and the hot water supply side main pipe 3 are connected to each other. A sealed tank unit 4 is connected with warm water between them.

  The sealed tank unit 4 has a pipe connection port 41 to which the upstream side of the water supply side main pipe 2 is connected, and a pressure reducing valve 42 that keeps the pressure of water flowing into the pipe connection port 41 constant. The water that has passed through is introduced into the lower part of the sealed tank 43, and the water in the sealed tank 43 is guided from the pipe connection port 42 to the downstream side of the water supply side main pipe 2. Further, the sealed tank unit 4 has a pipe connection port 45 to which the upstream side of the hot water supply side main pipe 3 is connected, and hot water that has flowed into the pipe connection port 45 flows into the upper part of the sealed tank 43 so that the sealed tank The stored hot water is temporarily stored in 43 and supplied to the open tank 5 through the pressure relief valve 46, the plurality of flow rate adjusting valves 51, 52, 53 and the pipe connection port 47. The flow rate adjusting valves 51, 52, 53 are connected in parallel to each other in the flow path of the hot water from the closed tank 43 to the open tank 5. The opening at the bottom of the sealed tank 43 serves as a water inlet and outlet, and the opening at the top of the sealed tank 43 serves as a warm water inlet and outlet. A plurality of temperature sensors T1, T2, T3, T4, and T5 are attached to the sealed tank 43 along the depth direction of the sealed tank 43. These temperature sensors T1, T2, T3, T4, and T5 are sequentially provided along the depth direction of the sealed tank 43, with the uppermost portion being a temperature sensor T5 and the lowermost portion being a temperature sensor T1.

  The water supply side main pipe 2 is connected to the opening at the bottom of the sealed tank 43, supplies water from a water source (not shown) to the sealed tank 43, and supplies the water in the sealed tank 43 to each heat source unit 1. It works to supply. The hot water supply side main pipe 3 functions to supply hot water flowing out from each heat source unit 1 to the sealed tank 43 and to supply hot water in the sealed tank 43 to the open tank 5.

  The open-type tank 5 stores hot water supplied from the hot water supply side main pipe 3 and supplies the stored hot water to a hot water supply load via a hot water pipe (not shown), in order to detect the level of hot water inside. Water level detecting means 6. As the water level detection means 6, the pressure sensor detects the pressure of hot water in the open bar 5 or an electrode bar detection unit that detects the water level by energizing each other through the liquid of a plurality of electrode bars having different lengths. Any of those that detect the water level from the detected pressure can be used.

A specific configuration of each heat source unit 1 is shown in FIG.
That is, the refrigerant discharged from the compressor 11 flows to the water heat exchanger 13 via the four-way valve 12, and the refrigerant that has passed through the water heat exchanger 13 is the expansion valve 14, which is a decompressor, the outdoor heat exchanger 15, and The air is sucked into the compressor 11 through the four-way valve 12. An outdoor fan 16 for supplying outside air to the outdoor heat exchanger 15 is provided in the vicinity of the outdoor heat exchanger 15. The equipment from the compressor 11 to the outdoor fan 16 constitutes a heat pump refrigeration cycle.
A first pipe 21 is connected from the water supply side main pipe 2 to one end of the first flow path of the first three-way valve 22, and the first flow path and the second flow path of the first three-way valve 22 are respectively connected from the other ends. A second pipe 23 is connected to the water inlet of the water heat exchanger 13 via a pump 24. Further, a third pipe 25 is connected to one end of each of the third flow path and the fourth flow path of the second three-way valve 26 from the water outlet of the water heat exchanger 13, and the first three-way is connected to the other end of the third flow path. A fourth pipe 27 is connected to one end of the second flow path of the valve 22. The fifth pipe 28 is connected to the hot water supply main pipe 3 from the middle of the fourth pipe 27, and the sixth pipe 29 is connected to the first pipe 21 from the other end of the fourth flow path of the second three-way valve 26. Is connected. A water cycle is constituted by these parts from the first pipe 21 to the sixth pipe 29.

  The first three-way valve 22 has a first flow path and a second flow path that can be selectively opened and closed, and the second three-way valve 26 is a third flow path and a fourth flow path that can be selectively opened and closed. have.

  A heat exchanger temperature sensor 31 is attached to the water heat exchanger 13, an inflow side temperature sensor 32 is attached in the vicinity of the water inlet of the water heat exchanger 13 in the second pipe 23, and the water heat exchanger 13 in the third pipe 25. An outflow temperature sensor 33 is attached in the vicinity of the water outlet. The heat exchanger temperature sensor 31 detects the temperature (condensation temperature) Tc (° C.) of the water heat exchanger 13. The inflow side temperature sensor 32 detects the temperature Twi (° C.) of water (or hot water) flowing into the water heat exchanger 13. The outflow side temperature sensor 33 detects the temperature Two (° C.) of the hot water (or water) flowing out from the water heat exchanger 13.

  A discharge refrigerant temperature sensor 61 and a high-pressure switch 62 are attached to the high-pressure side refrigerant pipe between the compressor 11 and the four-way valve 12, and a heat exchanger temperature sensor 63 is attached to the outdoor heat exchanger 15. The discharge refrigerant temperature sensor 61 detects the discharge refrigerant temperature Td of the compressor 11. The high pressure switch 62 operates when the discharge refrigerant pressure (high pressure side pressure) Pd of the compressor 11 increases abnormally. The heat exchanger temperature sensor 63 detects the temperature (evaporation temperature) Te (° C.) of the outdoor heat exchanger 15.

The heat source devices 1, the sealed tank unit 4, and the water level detection means 6 are connected to the control unit 7. The control unit 7 has the following means (1) to (12) as main functions.
(1) At the start of the operation of the heat source unit 1, the operation of the heat pump refrigeration cycle and the operation of the pump 24 are started, and the detected temperature Tc of the heat exchanger temperature sensor 31 or the detected temperature Twi of the inflow side temperature sensor 32 becomes a set value. Until the second three-way valve 26 is closed and the fourth flow path is opened, and the first three-way valve 22 is opened and the second flow path is closed. An initial circulation circuit in which water circulates through the heat exchanger 13, the third pipe 25, the fourth flow path of the second three-way valve 26, the sixth pipe 29, the first pipe 21, and the first flow path of the first three-way valve 22. Initial control means to form.

  (2) After the initial circulation circuit is formed by the initial control means, when the detected temperature Tc of the heat exchanger temperature sensor 31 or the detected temperature Twi of the inflow side temperature sensor 32 exceeds a set value, the first three-way valve 22 By opening the flow path and closing the second flow path, and opening the third flow path of the second three-way valve 26 and closing the fourth flow path, water in the water supply side main pipe 2 is supplied to the first pipe 21 and the first flow path. The first flow path of the three-way valve 22, the second pipe 23, and the pump 24 are sent to the water heat exchanger 13, and the hot water flowing out of the water heat exchanger 13 is supplied to the third pipe 25 and the third flow of the second three-way valve 26. A hot water control means for forming a hot water circuit that is sent to the hot water supply side main pipe 3 through the passage, the fourth pipe 27 and the fifth pipe 28.

  (3) Frost determination that determines that the outdoor heat exchanger 15 is frosted when the detected temperature Te of the heat exchanger temperature sensor 43 is lower than a set value (for example, 0 ° C.) for a predetermined time or longer. Judgment means.

  (4) When the determination result of the frost formation determination means is frost formation, the operation of the compressor 11 is stopped and the second three-way valve is determined based on the determination that the defrosting of the outdoor heat exchanger 15 is necessary. 26 opens the third flow path and closes the fourth flow path, and closes the first flow path of the first three-way valve 22 and opens the second flow path, so that the hot water is supplied to the water heat exchanger 13 and the third pipe. 25, hot water circulation control means for forming a hot water circulation circuit that circulates through the third flow path of the second three-way valve 26, the fourth pipe 27, the second flow path of the first three-way valve 22, and the pump 24.

  (5) After the hot water circulation circuit is formed by the hot water circulation control means, the operation of the compressor 11 is resumed and the refrigerant discharged from the compressor 11 passes through the outdoor heat exchanger 15, the expansion valve 14, and the water heat exchanger 13. Defrost control means for forming a defrost cycle that returns to the compressor 11.

  (6) After the defrost cycle is formed by the defrost control means, the first flow path of the first three-way valve 22 is closed to open the second flow path, and the third flow path of the second three-way valve 26 is closed. By opening the fourth flow path, the hot water in the hot water supply side main pipe 3 flows to the water heat exchanger 13 through the fifth pipe 28, the fourth pipe 27, the second flow path of the first three-way valve 22, and the pump 24. The dewatered hot water defrost flows through the water heat exchanger 13 through the third pipe 25, the fourth flow path of the second three-way valve 26, the sixth pipe 29, and the first pipe 21 to the water supply side main pipe 2. Hot water defrost control means for forming a circuit.

  (7) After the formation of the hot water defrosting circuit by the hot water defrosting control means, when the detected temperature Two of the outflow side temperature sensor 33 rises above a predetermined value (Twoa + ΔT), Switching control means for switching to formation and switching to formation of the hot water defrosting circuit from the hot water circulation circuit when the detected temperature Two of the outflow side temperature sensor 33 falls below a predetermined value Twoa.

  (8) The number of operating heat source units 1 and the opening of the flow rate adjusting valves 51, 52, 53 according to, for example, the temperature detected by the temperature sensor T4 located on the upper side of the temperature sensors T1, T2, T3, T4, T5. First control means for controlling the degree; When an abnormality occurs in any of the temperature sensors T1, T2, T3, T4, and T5, the temperature sensor excluding the temperature sensor in which the abnormality has occurred depends on the detection temperature of the temperature sensor located on the upper side as much as possible. Thus, the condition that the number of operating heat source devices 1 and the opening degree of the flow rate adjusting valves 51, 52, 53 are controlled is set. That is, when an abnormality occurs in the temperature sensor T4, for example, the temperature detected by the temperature sensor T5 is corrected for the temperature sensor T4 and used for control. When an abnormality occurs in the temperature sensors T4 and T5, the temperature sensor T3 detects The temperature is corrected for the temperature sensor T4 and used for control.

  (9) Second control means for reducing the number of operating heat source units 1 regardless of the control of the first control means when the detected water level of the water level detection means 6 reaches near full water.

  (10) Third control means for stopping the operation of each heat source unit 1 regardless of the control of the first control means when the detected water level of the water level detection means 6 reaches full water.

  (11) When the operation of each heat source unit 1 is stopped when the detected water level of the water level detection means 6 has not reached the full level, the flow rate is adjusted until the detected temperature of the uppermost temperature sensor T5 continues below a predetermined value for a certain period of time. Fourth control means for keeping the valves 51, 52, and 53 open and guiding the warm water in the sealed tank 43 to the open tank 5 and then fully closing the flow rate adjusting valves 51, 52, and 53.

  (12) Fifth control means for fully opening the remaining flow control valves regardless of the control of the first control means when any of the flow control valves 51, 52, 53 is abnormal.

Next, the operation of the above configuration will be described.
(A) Initial circulation circuit and tapping circuit
At the start of the operation of the heat source unit 1, the operation of the heat pump refrigeration cycle and the operation of the pump 24 are started until the detected temperature Tc of the heat exchanger temperature sensor 31 reaches the set value Tcs based on the conditions shown in FIG. Until the detection temperature Twi of the inflow side temperature sensor 32 reaches the set value Twis, the third flow path of the second three-way valve 26 is closed and the fourth flow path is opened, and the first flow path of the first three-way valve 22 is opened. Is opened and the second flow path is closed. As a result, as shown by arrows in FIG. 2, in the heat pump refrigeration cycle, the refrigerant discharged from the compressor 11 passes through the four-way valve 12, the water heat exchanger 13, the expansion valve 14, the outdoor heat exchanger 15, and the four-way valve 12. Thus, a flow sucked into the compressor 11 is generated, and the water heat exchanger functions as a condenser. In the water cycle, water flows through the pump 24, the water heat exchanger 13, the third pipe 25, the fourth flow path of the second three-way valve 26, the sixth pipe 29, the first pipe 21, and the first flow of the first three-way valve 22. An initial circulation circuit that circulates through the path is formed.

  After the initial circulation circuit is formed, based on the conditions shown in FIG. 3, when the detected temperature Tc of the heat exchanger temperature sensor 31 exceeds the set value Tcs, or the detected temperature Twi of the inflow side temperature sensor 32 becomes the set value Twis. When exceeded, the first flow path of the first three-way valve 22 is opened and the second flow path is closed, and the third flow path of the second three-way valve 26 is opened and the fourth flow path is closed. As a result, as shown by arrows in FIG. 4, the water in the water supply side main pipe 2 passes through the first pipe 21, the first flow path of the first three-way valve 22, the second pipe 23, and the pump 24, and the water heat exchanger. The hot water flowing out from the water heat exchanger 13 passes through the third pipe 25, the third flow path of the second three-way valve 26, the fourth pipe 27, and the fifth pipe 28 to the hot water supply side main pipe 3. A feeding hot water circuit is formed.

  Thus, at the start of operation, an initial circulation circuit is first formed to warm the water heat exchanger 13, and after the water heat exchanger 13 is sufficiently warmed, the hot water is discharged to the hot water supply side main pipe 3, thereby The unnecessary temperature drop of the hot water flowing through the side main pipe 3 can be avoided, and high-temperature water whose temperature has risen sufficiently is supplied to the hot water supply side main pipe 3 and the sealed tank 43.

In particular, since a plurality of heat source units 1 are provided and the number of operating heat source units 1 can be changed, the overall hot water supply capacity can be increased and the hot water supply capacity can be adjusted in a wide range. (B) Stop Of inflow of hot water into the heat source unit 1
In the stopped heat source unit 1, the third flow path of the second three-way valve 26 is closed and the fourth flow path is opened, and the first flow path of the first three-way valve 22 is opened and the second flow path is opened. The hot water supply circuit is closed and the initial circulation circuit of FIG. 2 is prepared. As a result, the hot water in the hot water supply side main pipe 3 made by the operating heat source unit 1 does not flow into the water cycle of the stopped heat source unit 1, and the hot water made by the operating heat source unit 1 and The heat energy can be supplied and stored in the sealed tank 43 without waste, and energy saving and reliability can be improved.

(C) Defrosting
During operation of the heat source apparatus 1, frost gradually adheres to the surface of the outdoor heat exchanger 15 that functions as an evaporator. Therefore, during operation, the detected temperature Te of the heat exchanger temperature sensor 43 is monitored, and if the detected temperature Te continues below a set value (for example, 0 ° C.) for a predetermined time or longer, the outdoor heat exchanger 15 is frosted. It is determined that

  At the time of this frost determination, the defrosting operation is performed based on the determination that the outdoor heat exchanger 15 needs to be defrosted.

  In this defrosting operation, the operation of the compressor 11 is stopped for the first few seconds, and in the water cycle, the third flow path of the second three-way valve 26 is opened as shown by the arrow in FIG. The passage is closed, the first flow path of the first three-way valve 22 is closed and the second flow path is opened, and the hot water is the third flow of the water heat exchanger 13, the third pipe 25, and the second three-way valve 26. A hot water circulation circuit that circulates through the passage, the fourth pipe 27, the second flow path of the first three-way valve 22, and the pump 24 is formed. By forming this hot water circulation circuit, the whole including the refrigerant flow path region of the water heat exchanger 13 is preheated with hot water and becomes a high temperature uniform state.

  After the first few seconds have passed, the operation of the compressor 11 is resumed while the hot water circulation circuit is maintained, and the four-way valve 12 is switched. As shown by the arrows in FIG. A defrost cycle that returns to the compressor 11 through the four-way valve 12, the outdoor heat exchanger 15, the expansion valve 14, and the water heat exchanger 13 is formed. By this hot water circulation circuit and the defrost cycle, the remaining heat of the hot water in the water cycle is effectively used as the defrost heat for the outdoor heat exchanger 15.

  Thus, when defrosting using preheating of hot water is performed, if the detection temperature Two of the outflow side temperature sensor 33 falls below a predetermined value Twoa as shown in FIG. 6, defrosting due to preheating has reached its limit. In this case, since the outdoor heat exchanger 15 may be frozen if it remains as it is, the first flow path of the first three-way valve 22 is closed, the second flow path is opened, and the second three-way The third flow path of the valve 26 is closed and the fourth flow path is opened. Accordingly, as indicated by arrows in FIG. 7, the hot water in the hot water supply side main pipe 3 passes through the fifth pipe 28, the fourth pipe 27, the second flow path of the first three-way valve 22, and the pump 24, and the water heat exchanger. The hot water flows to the water supply side main pipe 2 through the third pipe 25, the fourth flow path of the second three-way valve 26, the sixth pipe 29, and the first pipe 21. A utilization defrosting circuit is formed. With this hot water utilization defrosting circuit, the heat of the hot water in the hot water supply side main pipe 3 or the sealed tank 43 is used for defrosting the outdoor heat exchanger 15.

  In the hot water defrosting circuit, the water that has passed through the water heat exchanger 13 passes through the third pipe 25, the fourth flow path of the second three-way valve 26, the sixth pipe 29, and the first pipe 21, and the water supply side main pipe 2, if the amount of heat transferred to the defrosting side in the water heat exchanger 13 is small and the temperature drop of the water flowing out from the water heat exchanger 13 is small, high temperature water is supplied to the water supply side main pipe 2. The situation of flowing in and flowing into the water cycle of another heat source machine 1 occurs. In this case, in the other heat source unit 1 into which high-temperature water has flowed in, the high-pressure side pressure of the refrigeration cycle rises abnormally, the high-pressure switch 42 is activated, and the high-pressure protection control is activated to stop the operation unnecessarily. There is.

  In order to avoid such an unnecessary operation stop due to the high pressure protection control, when the detected temperature Two of the outflow side temperature sensor 33 rises to a predetermined value (Twoa + ΔT) or more in accordance with the conditions of FIG. Switch to circuit.

  When the detected temperature Two of the outflow side temperature sensor 33 falls below a predetermined value Twoa, the hot water circulation circuit is switched to the hot water defrost circuit in order to obtain sufficient defrost heat.

(D) Temperature control
When the operation is started, the water from the water supply side main pipe 2 and the hot water from the hot water supply side main pipe 3 flow into the sealed tank 43 together. The temperature of water and warm water in the sealed tank 43 is detected by temperature sensors T1, T2, T3, T4, and T5, and the detected temperature (that is, hot water temperature) of the temperature sensor T4 located on the upper side among these temperature sensors is detected. The number of operating heat source devices 1 and the opening degree of the flow rate adjusting valves 51, 52, 53 are controlled so as to maintain the set values.

  For example, at the start of operation, if the detected temperature of the temperature sensor T4 is lower than a set value, a predetermined number of heat source units 1 corresponding to the detected temperature are activated, and if the detected temperature of the temperature sensor T4 reaches the set value, the flow rate is adjusted. The opening degree of the valves 51, 52, 53 is set to the initial opening degree corresponding to the number of the activated valves, and the fully closed flow rate adjusting valves 51, 52, 53 are opened at the initial opening degree for 1 minute. After 1 minute, the opening degree of the flow rate adjusting valves 51, 52, 53 is controlled so that the temperature detected by the temperature sensor T4 maintains the set value.

  By this temperature control, hot water having a temperature required for hot water supply can be always stored in the open tank 5. In particular, since the plurality of flow rate adjusting valves 51, 52, 53 connected in parallel to each other are provided in the flow path of the hot water, the flow rate of the hot water to the open tank 5 can be finely adjusted. As a result, stable hot water supply to the hot water supply load is always possible, improving the reliability of hot water supply, and high temperature hot water is present in the upper layer area of the sealed tank 43, and low temperature water is present in the lower layer area. An ideal hot water temperature distribution is formed.

  If any abnormality occurs in the temperature sensor T4, for example, the temperature detected by the temperature sensor T5 is corrected for the temperature sensor T4 and used for control. If any abnormality occurs in the temperature sensors T4 and T5, the temperature sensor T3 is used. The detected temperature is corrected for the temperature sensor T4 and used for control. Thereby, the temperature control can be continued regardless of the abnormality of the temperature sensor T4.

(E) Full water control
When the open tank 5 is almost full, the flow rate of the hot water flowing through the open tank 5 is reduced due to the reverse pressure from the open tank 5 even if the flow rate adjusting valves 51, 52, 53 are fully opened. If this is the case, the ideal hot water temperature distribution in which the sealed tank 43 is filled with hot water, high temperature hot water exists in the upper layer area of the sealed tank 43 and low temperature water exists in the lower layer area collapses, and the sealed type tank 43 is closed. Hot water will flow out from the lower part of the tank 43 to the heat source device 1 side. This outflow of warm water is not preferable because, in addition to wasting heat energy, the heat pump refrigeration cycle in each heat source unit 1 becomes a superheated load operation and causes an abnormal increase in the high-pressure side pressure.

  Therefore, when the detected water level of the water level detecting means 6 in the open tank 5 reaches near full water, the number of operating heat source devices 1 is forcibly reduced regardless of the control according to the temperature detected by the temperature sensor T4. This reduction in the number of operating units prevents the closed tank 43 from being filled with hot water.

  Moreover, when the detection water level of the water level detection means 6 reaches full water, the operation of each heat source unit 1 is forcibly stopped for safety.

(F) Effective use of hot water after stopping
When the operation of each heat source unit 1 is stopped when the detected water level of the water level detection means 6 has not reached full water, the detected temperature of the uppermost temperature sensor T5 is used to effectively use the hot water stored in the sealed tank 43. The flow rate adjusting valves 51, 52, and 53 are maintained in an open state until a state less than a predetermined value, for example, less than 30 ° C. or less than 35 ° C., is continued for a certain time, for example, 3 minutes. Thereby, the hot water in the sealed tank 43 is guided to the open tank 5. Thereafter (after the elapse of 3 minutes), the flow rate adjustment valves 51, 52, 53 are fully closed, and the problem that hot water whose temperature is not so high flows from the sealed tank 43 to the open tank 5 is prevented.

(G) Abnormal flow adjustment valve
When an abnormality occurs in any of the flow rate adjusting valves 51, 52, 53, the remaining flow rate adjusting valves are fully opened regardless of the control according to the temperature detected by the temperature sensor T4. In this case, the hot water temperature cannot be controlled, but it is possible to avoid a situation in which the hot water in the sealed tank 43 flows backward to each heat source unit 1 and does not flow to the open tank 5. Cutting can be prevented.

(H) Modification
In the above-described embodiment, three flow rate adjustment valves are used. In addition, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the invention.

The figure which shows the structure of one Embodiment. The figure which shows the specific structure and initial stage circulation circuit of the heat-source equipment in one Embodiment. The figure which shows the switching conditions of the initial stage circulation circuit and the tapping circuit in one Embodiment. The figure which shows the tapping circuit of the heat-source machine in one Embodiment. The figure which shows the defrost cycle and warm water circulation cycle in one Embodiment. The figure which shows the switching conditions of the defrost cycle and warm water circulation cycle in one Embodiment. The figure which shows the defrost cycle and warm water utilization defrost cycle in one Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Heat source machine, 2 ... Water supply side main piping, 3 ... Hot water supply side main piping, 4 ... Sealed tank unit, 5 ... Open type tank, 6 ... Water level detection means, 7 ... Control part, 11 ... Compressor, 13 ... Water heat exchanger, 14 ... expansion valve (pressure reducer), 15 ... outdoor heat exchanger, 21 ... first pipe, 22 ... first three-way valve, 23 ... second pipe, 24 ... pump, 25 ... third pipe, 26 ... 2nd three-way valve, 27 ... 4th piping, 28 ... 5th piping, 29 ... 6th piping, 31 ... Heat exchanger temperature sensor, 32 ... Inflow side temperature sensor, 33 ... Outflow side temperature sensor, 43 ... Sealing Mold tank, 51, 52, 53 ... Flow rate adjusting valve, T1-T5 ... Temperature sensor

Claims (4)

Water is supplied to the sealed tank, and the water in the sealed tank is heated by each heat source device to make warm water. The warm water is temporarily stored in the sealed tank, and the warm water in the sealed tank is stored in the open tank. In the hot water supply device that supplies and stores,
A flow rate adjusting valve provided in a flow path of hot water from the sealed tank to the open tank;
A temperature sensor for detecting the temperature of hot water in the sealed tank;
Control means for controlling the opening of the flow rate adjusting valve according to the temperature detected by the temperature sensor;
Water level detecting means for detecting the water level in the open-type tank;
With
The control means includes first control means for controlling the number of operating heat source units and the opening degree of the flow rate adjusting valve according to the temperature detected by the temperature sensor, and the water level detected by the water level detecting means reaches near full. In this case, regardless of the control of the first control means, the second control means for reducing the number of operating each heat source unit, and the control of the first control means when the detected water level of the water level detection means reaches full water. Regardless of the third control means for stopping the operation of each of the heat source devices, and when the operation of each of the heat source devices is stopped when the detected water level of the water level detecting means has not reached full water, the temperature detected by the temperature sensor is less than a predetermined value. A fourth control means for maintaining the open state of the flow rate adjustment valve until the state is maintained for a certain period of time, guiding hot water in the sealed tank to the open type tank, and then fully closing the flow rate adjustment valve; Have
A water heater characterized by that.   The sealed tank has an inlet for water to be supplied and an outlet for water to each heat source unit at the bottom, and an inlet for hot water from each heat source unit and a flow of hot water to the open type tank. The hot water supply apparatus according to claim 1, further comprising an outlet at an upper portion. The flow rate regulating valve is a plurality of flow rate regulating valves connected in parallel to each other,
The control means further includes fifth control means for fully opening the remaining flow rate adjustment valves regardless of the control of the first control means when an abnormality occurs in any of the flow rate adjustment valves.
The hot water supply apparatus according to claim 1. Water is supplied to the sealed tank, and the water in the sealed tank is heated by each heat source device to make warm water. The warm water is temporarily stored in the sealed tank, and the warm water in the sealed tank is stored in the open tank. In the hot water supply device that supplies and stores,
A flow rate adjusting valve provided in a flow path of hot water from the sealed tank to the open tank;
A temperature sensor for detecting the temperature of hot water in the sealed tank;
Control means for controlling the opening of the flow rate adjusting valve according to the temperature detected by the temperature sensor;
With
The temperature sensors are a plurality of temperature sensors sequentially provided along the depth direction of the sealed tank.
The control means controls the number of operating heat source units and the opening of the flow rate adjustment valve so that the detected temperature of the temperature sensor located on the upper side among the temperature sensors maintains a set value, When an abnormality occurs in any of the temperature sensors, among the temperature sensors excluding the temperature sensor in which the abnormality has occurred, the number of operating heat source devices and the number of the heat source devices according to the detected temperature of the temperature sensor located on the upper side as much as possible Control the opening of the flow control valve,
A water heater characterized by that.

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