JP5095295B2 - Water heater - Google Patents

Description

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

  It has a heat pump refrigeration cycle that passes the refrigerant discharged from the compressor through the water heat exchanger, decompressor, and outdoor heat exchanger, returns it to the compressor, and makes the water heat exchanger function as a condenser. There is a hot water supply device that stores hot water in a tank by circulating through an exchanger (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 conceivable that a part of the hot water flowing out from the operating heat source unit flows into the stopped heat source unit. In this case, the warm water and the heat energy made with great care are wasted.

  The present invention takes the above-mentioned circumstances into consideration, and its purpose is to prevent a situation in which a part of hot water flowing out from the operating heat source machine flows into the stopped heat source machine. It is an object of the present invention to provide a hot water supply device that is excellent in energy saving and reliability, and can supply hot water produced by the heat source machine and its heat energy to a load without waste.

The hot water supply apparatus of the invention according to claim 1 is a heat pump refrigeration cycle in which refrigerant discharged from the compressor is passed through a water heat exchanger, a decompressor, and an outdoor heat exchanger and returned to the compressor to function as a condenser. A plurality of heat source units having a water cycle that sends water from the water supply side main pipe to the water heat exchanger by a pump and guides hot water flowing out of the water heat exchanger to the hot water side main pipe, and each heat source unit is provided with A first valve for controlling the flow of water between the water cycle and the water supply side main pipe, and the hot water between the water cycle and the hot water side main pipe provided in each of the heat source units. And a second valve for controlling the flow of. The first valve is a first three-way valve having a first flow path and a second flow path that can be selectively opened and closed. The second valve is a second three-way valve having a third flow path and a fourth flow path that can be selectively opened and closed. The water cycle of each of the heat source units includes a first pipe connected from the water supply side main pipe to one end of the first flow path of the first three-way valve, and the pump from the other end of each flow path of the first three-way valve. A second pipe connected to the water inlet of the water heat exchanger via the third outlet, a third pipe connected to one end of each flow path of the second three-way valve from the water outlet of the water heat exchanger, the second A fourth pipe connected from the other end of the third flow path of the three-way valve to one end of the second flow path of the first three-way valve, and a fifth pipe connected from the middle part of the fourth pipe to the hot water supply side main pipe The pipe has a sixth pipe connected to the first pipe from the other end of the fourth flow path of the second three-way valve.

  According to the hot water supply apparatus of the present invention, part of the hot water flowing out from the operating heat source unit does not flow into the stopped heat source unit. Therefore, it is possible to supply the hot water produced by the heat source machine in operation and its thermal energy to the load without waste, and energy saving and reliability can be improved.

[1] A first embodiment of the present invention will be described below 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 4 is connected between them. The water supply side main pipe 2 supplies water from a water source (not shown) to the sealed tank 4 and each heat source unit 1 and supplies water (or hot water) in the sealed tank 4 to each heat source unit 1. The hot water supply side main pipe 3 supplies hot water flowing out from each heat source unit 1 to the sealed tank 4 and supplies hot water in the sealed tank 4 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 it to the load side.

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 41 and a high-pressure switch 42 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 43 is attached to the outdoor heat exchanger 15. The discharge refrigerant temperature sensor 41 detects the discharge refrigerant temperature Td of the compressor 11. The high pressure switch 42 is activated when the discharge refrigerant pressure (high pressure side pressure) Pd of the compressor 11 is abnormally increased. However, the high voltage switch 42 can be omitted when an abnormal rise in Pd is determined by another sensor or the like.

The heat exchanger temperature sensor 43 detects the temperature (evaporation temperature) Te (° C.) of the outdoor heat exchanger 15.

Each of the heat source devices 1 is connected to the control unit 7. The controller 7 is further connected to an outside air temperature sensor 8 that detects an outside air temperature To (° C.). The control unit 7 includes the following means (1) to (14) 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. 1st control means to form.

  (2) After the initial circuit is formed by the first 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 one 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, the water in the water supply side main pipe 2 is supplied to the first pipe 21 and the second flow path. The first flow path of the one-way valve 22, the second pipe 23, and the pump 24 are sent to the water heat exchanger 13, and the warm water flowing out of the water heat exchanger 13 is transferred to the third pipe 25 and the third of the second three-way valve 26. Second control means for forming a tapping circuit for sending to the hot water supply side main pipe 3 through the flow path, the fourth pipe 27 and the fifth pipe 28.

  (3) Third control means for setting the rotational speed at the start of operation of the pump 24 in accordance with the detected temperature To of the outside air temperature sensor 8.

  (4) The rotational speed of the pump 24 set by the third control means is determined when the detected temperature Twi of the inflow side temperature sensor 32 is less than a predetermined value (= equivalent to the set value Tca with respect to the condensation temperature Tc). Increase / decrease correction according to the operating frequency F (Hz), the detected temperature Two of the outflow temperature sensor 33, the detected temperature Tc of the heat exchanger temperature sensor 31, and the detected temperature Td of the discharged refrigerant temperature sensor 41, and the inflow side temperature. Fourth control means for performing increase / decrease correction according to the detected temperature Tc of the heat exchanger temperature sensor 31 and the detected temperature Td of the discharged refrigerant temperature sensor 41 when the detected temperature Twi of the sensor 32 is equal to or higher than the predetermined value.

  (5) The rate of change in the rotational speed of the pump 24 when correcting the increasing direction by the fourth control means is set to X (rpm / sec) when the detected temperature Tc of the heat exchanger temperature sensor 31 is equal to or higher than the set value Tcb. And fifth control means for setting to Y (rpm / sec) when it is less than the set value Tcb. Note that X> Y.

  (6) Sixth control means for delaying the start of operation of the heat pump refrigeration cycle by the first control means by a fixed time.

  (7) When the operation of the heat source unit 1 is stopped, the operation of the heat pump refrigeration cycle is first stopped, and the second operation is continued while the operation of the pump 24 is continued until the detected temperature Two of the outflow side temperature sensor 33 decreases to a constant value. Seventh control means for continuing the formation of the tapping circuit by the control means.

  (8) After stopping the operation of the heat pump refrigeration cycle by the seventh control means, if the detected temperature Two of the outflow side temperature sensor 33 falls below a certain value, the operation of the pump 24 is stopped and the second three-way valve 22 By closing the 3 flow paths and opening the 4th flow path, and opening the 1st flow path of the 1st three-way valve 26 and closing the 2nd flow path, the formation of the tapping circuit is canceled (formation of the initial circulation circuit is performed). 8th control means to prepare.

  (9) Before the hot water circuit is formed by the second control means, the rotational speed of the pump 24 is increased to the hot water speed while the initial circulation circuit is formed by the first control means. 9 Control means.

  (10) Frosting that determines that the outdoor heat exchanger 15 is frosted when the detected temperature Te of the heat exchanger temperature sensor 43 is kept below a set value (for example, 0 ° C.) for a predetermined time or longer. Judgment means.

  (11) 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, tenth 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.

  (12) After the hot water circulation circuit is formed by the tenth 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. And an eleventh control means for forming a defrost cycle returning to the compressor 11.

  (13) After the defrost cycle is formed by the eleventh 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. 12th control means which forms a circuit.

  (14) After the hot water defrosting circuit is formed by the twelfth control means, when the detected temperature Two of the outflow side temperature sensor 33 rises to a predetermined value (Twoa + ΔT) or more according to the conditions of FIG. Switching to the formation of the hot water circulation circuit by the tenth control means, and when the detected temperature Two of the outflow side temperature sensor 33 falls below the predetermined value Twoa, the hot water circulation circuit is switched to the formation of the hot water defrosting circuit by the twelfth control means. 13 control means.

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 4.

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 thermal energy can be supplied and stored in the sealed tank 4 without waste, and energy saving and reliability can be improved.

(C) Speed of pump 24
The number of rotations of the pump 24 depends on the number of heat source devices 1 connected between the water supply side main pipe 2 and the hot water supply side main pipe 3, the pipe length and the pipe diameter of the water supply side main pipe 2 and the hot water supply side main pipe 3. Even if is constant, the flow rate of water flowing through the heat source unit 1 is different.

  For this reason, it is necessary to vary the rotation speed of the pump 24 within a range in which the detection temperature Two of the outflow temperature sensor 33 can reach the set temperature with respect to the flow rate flowing to the heat source unit 1. As for the rotation speed of the pump 24, the initial rotation speed at the start of operation is first set according to the detection temperature To of the outside air temperature sensor 8, and then the operation frequency F (Hz) of the compressor 11 and the detection of the outflow side temperature sensor 33. Increase / decrease control is performed according to the temperature Two, the detected temperature (condensation temperature) Tc of the heat exchanger temperature sensor 31, the detected temperature Td of the discharged refrigerant temperature sensor 41, and the like.

  There are two types of increase / decrease control. When the detected temperature Twi of the inflow side temperature sensor 32 is less than a predetermined value, the increase / decrease control shown in FIG. 5 to FIG. 8 is executed. Increase control shown in FIGS. 9 to 11 is executed.

  That is, under the condition that the detected temperature Twi of the inflow side temperature sensor 32 is less than a predetermined value, the operating frequency F (Hz) of the compressor 11 is less than F1, as shown in FIG. 5, and the outflow side temperature sensor 33, as shown in FIG. The detected temperature Two is equal to or higher than Two1, the detected temperature Tc of the heat exchanger temperature sensor 31 is higher than Tc3 as shown in FIG. 7, and the detected temperature Td of the discharged refrigerant temperature sensor 41 is higher than Td1 as shown in FIG. Since the flow rate of water flowing through the heat source unit 1 is small when the temperature continues for a predetermined number of seconds, it is determined that the heat exchanger temperature sensor 31 is high and the high pressure is high, and the rotational speed of the pump 24 is increased. To reduce the heat exchanger temperature. At this time, by introducing the conditions of the temperature of the outflow temperature sensor 33 and the operating frequency of the compressor 11, a decrease in the outflow side temperature due to an increase in flow rate is prevented. Further, the operating frequency F (Hz) of the compressor 11 is F1 or more, the detection temperature Two of the outflow side temperature sensor 33 is less than Two2, the detection temperature Tc of the heat exchanger temperature sensor 31 is less than Tc2, Tc1 or more, the discharge refrigerant temperature sensor When each of the conditions that the detected temperature Td of 41 is less than Td3 continues for a predetermined number of seconds, it is determined that the flow rate of water flowing through the heat source unit 1 is large and the outflow temperature does not reach the set temperature. The rotational speed is corrected in the decreasing direction.

  Under the condition that the detected temperature Twi of the inflow side temperature sensor 32 is equal to or higher than a predetermined value, the detected temperature Tc of the outflow side temperature sensor 33 is equal to or higher than Tca as shown in FIG. 9, and the detected temperature of the discharged refrigerant temperature sensor 41 as shown in FIG. When the state where Td is equal to or greater than Tdb continues for a predetermined number of seconds, the rotational speed of the pump 24 is corrected in the increasing direction.

  In the correction of the increasing direction of the rotational speed of the pump 24, the rotational speed change rate of the pump 24 is switched according to the conditions shown in FIG. That is, if the detected temperature Tc of the heat exchanger temperature sensor 31 is equal to or higher than the set value Tcb, the pressure is quickly reduced by setting the rotation speed change width to a larger X (rpm / sec). If the detected temperature Tc is less than the set value Tcb, the rotational speed change rate is set to Y (rpm / sec) smaller than X.

(D) Operation of heat pump refrigeration cycle in initial circulation circuit
When the operation of the heat source unit 1 is started, the operation start of the heat pump refrigeration cycle (operation start of the compressor 11) is delayed by a certain time. This is because when the water heat exchanger 13 starts operation with medium-high temperature hot water that is in equilibrium with the outside air temperature, the initial circulation circuit of the water cycle is immediately terminated and switched to the hot water circuit. Addresses a problem that hot water that is not warm enough is discharged. That is, when the operation start of the heat pump refrigeration cycle is delayed for a certain time, for example, several seconds, the hot water existing in the water heat exchanger 13 is once discharged from the water heat exchanger 13 by the initial circulation circuit, and the water temperature of the water cycle is reduced. It is made uniform. Thereafter, operation of the heat pump refrigeration cycle (operation of the compressor 11) is started. Thereby, the malfunction that warm water with low temperature is discharged can be eliminated.

(E) Stop operation of heat pump refrigeration cycle
When the operation of the heat source unit 1 is stopped, first, the operation of the heat pump refrigeration cycle (the operation of the compressor 11) is stopped, and the operation of the pump 24 and the hot water circuit until the detected temperature Two of the outflow temperature sensor 33 decreases to a constant value. The formation of is continued. This is because immediately after the operation stop of the heat pump refrigeration cycle (stop of the compressor 11), the high-temperature water that has been boiled up to that time remains in the water heat exchanger 13, and the high-temperature water is discharged without waste. is there. In this way, the preheating after the stop of operation can be used up sufficiently, and it becomes difficult for hot water of medium to high temperature to remain in the water heat exchanger 13 at the start of the next operation, and the fixed time for delaying the start of operation is shortened as much as possible. can do. This shortening leads to shortening of the rise time until the hot water.

  When the detected temperature Two of the outflow temperature sensor 33 falls below a certain value after the operation of the heat pump refrigeration cycle is stopped, the operation of the pump 24 is stopped and the third flow path of the second three-way valve 22 is closed and The four flow paths are opened, the first flow path of the first three-way valve 26 is opened, and the second flow path is closed. Thereby, the hot water circuit is released and the initial circulation circuit is prepared, so that the next smooth start of operation can be prepared. As described in (b) above, 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.

(F) Increase in the rotational speed of the pump 24 before switching from the initial circulation circuit to the tapping circuit
As shown in the time chart of FIG. 12, before the hot water circuit is formed, the rotational speed of the pump 24 is increased to the rotational speed for hot water with the initial circulation circuit formed.

  When the initial circulation circuit is formed, the pressure of the water cycle is lower than the pressure of the hot water supply side main pipe 3. If the hot water circuit is formed in this state, there is a concern that the hot water in the hot water supply side main pipe 3 flows back into the water cycle.

  Therefore, before the hot water circuit is formed, the rotational speed of the pump 24 is increased to the rotational speed for hot water in advance. Thereby, the malfunction that the warm water in the hot water supply side main piping 3 flows backward to a water cycle can be prevented beforehand.

(G) 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, as shown in FIG. 13, the third flow path of the second three-way valve 26 is opened and the fourth flow path is opened. 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 supplied from the water heat exchanger 13, the third pipe 25, the third flow path of the second three-way valve 26, A hot water circulation circuit that circulates through 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, the operation of the compressor 11 is restarted while the hot water circulation circuit is maintained, and the four-way valve 12 is switched. As shown in FIG. 13, the refrigerant discharged from the compressor 11 is discharged to the four-way valve. 12, the defrost cycle which returns to the compressor 11 through 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 temperature sensor 33 falls below a predetermined value Twoa, under the determination that defrosting by preheating has reached its limit, Further, since there is a concern that the water heat exchanger 13 may be frozen as it is, the first flow path of the first three-way valve 22 is closed and the second flow path is opened, and the third flow of the second three-way valve 26 is opened. The path is closed and the fourth flow path is opened. Accordingly, as shown in FIG. 15, 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 to the water heat exchanger 13. The use of hot water that flows through the water heat exchanger 13 and flows 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 A frost 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 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 temperature sensor 33 rises to a predetermined value (Twoa + ΔT) or more according to 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.

[2] A second embodiment of the present invention will be described.
As shown in FIG. 16, in the refrigerant flow path of the heat pump refrigeration cycle of each heat source apparatus 1, a bypass 51 is connected in parallel to the water heat exchanger 13, and a two-way valve 52 is provided in the bypass 51. . Furthermore, a flow rate adjusting valve 53 is provided on the side of the water heat exchanger 13 from the connection position of the bypass 51 in the refrigerant flow path between the water heat exchanger 13 and the expansion valve 14 of the heat pump refrigeration cycle.

  The bypass 51 is for bypassing a part of the refrigerant that flows to the water heat exchanger 13 side when the defrost cycle is formed. The two-way valve 52 is for opening and closing the bypass 51. The flow rate adjusting valve 53 can freely change the opening degree and adjusts the amount of refrigerant flowing into the water heat exchanger 13 when the defrost cycle is formed.

And the control part 7 has the following means (15) (16) in addition to the means (1)-(14) of 1st Embodiment as main functions.
(15) When forming the defrosting circuit using hot water by the twelfth control means, the two-way valve 52 is closed if the detected temperature Tc of the heat exchanger temperature sensor 31 is equal to or higher than a predetermined value Tcc based on the switching conditions of FIG. 14th control means which performs normal defrosting, opens the two-way valve 52, and performs what is called parallel defrosting by conduction of bypass 51, when the detection temperature Tc becomes less than predetermined value Tcc. Although the detection temperature Tc of the heat exchanger temperature sensor 31 is used, the detection temperature Twi of the inflow side temperature sensor 32 or the detection temperature Two of the outflow side temperature sensor 33 may be used.

  (16) When the two-way valve 52 is opened by the fourteenth control means (at the time of parallel defrosting), the opening degree of the flow rate adjustment valve 53 is controlled to be narrowed as the detected temperature Two of the outflow temperature sensor 33 is lower. 15th control means. Although the detection temperature Two of the outflow side temperature sensor 33 is used, the detection temperature Two of the inflow side temperature sensor 32 may be used.

The operation will be described.
As shown in FIG. 16, when the hot water defrosting circuit is formed and the hot water in the hot water supply side main pipe 3 flows into the water heat exchanger 13, the hot water use main pipe 3 flows into the water heat exchanger 13. If the temperature of the hot water decreases for some reason, or if the circulation rate of the hot water flowing through the water heat exchanger 13 decreases for some reason, the water heat exchanger 13 functioning as an evaporator may be frozen. .

  Therefore, the detected temperature Tc of the heat exchanger temperature sensor 31 is monitored, and normal defrosting and parallel defrosting are selectively performed based on a comparison between the detected temperature Tc and the switching condition shown in FIG.

  First, if the detected temperature Tc is equal to or higher than the predetermined value Tcc, the two-way valve 52 is closed and the bypass 51 is shut off by determining that there is no risk of freezing of the water heat exchanger 13, and the outdoor heat is Normal defrosting is performed in which the refrigerant that has passed through the exchanger 15 flows to the water heat exchanger 13 as it is.

  However, when the detected temperature Tc falls below the predetermined value Tcc, the two-way valve 52 is opened and the bypass 51 is conducted under the judgment that the water heat exchanger 13 may be frozen. Due to the conduction of the bypass 51, a part of the refrigerant that has passed through the outdoor heat exchanger 15 flows into the bypass 51, and the amount of the refrigerant flowing into the water heat exchanger 13 decreases accordingly. Due to the decrease in the refrigerant flow rate, freezing of the water heat exchanger 13 is prevented.

  In this anti-freezing control, the detected temperature Two of the outflow side temperature sensor 33 is monitored, and the lower the detected temperature Two, the smaller the opening degree of the flow rate adjustment valve 53 and the amount of refrigerant flowing into the water heat exchanger 13 becomes. Reduced.

  If the detected temperature Two of the outflow temperature sensor 33 continues to decrease despite the execution of the freeze prevention control, the flow rate adjustment valve 53 is fully closed as a final freeze prevention measure, as shown in FIG. In addition, the inflow of the refrigerant to the water heat exchanger 13 is blocked. In this case, the outdoor heat exchanger 15 is defrosted only with the heat of the refrigerant discharged from the compressor 11.

  Other configurations, operations, and effects are the same as those in the first embodiment. Therefore, the description is omitted.

[3] Modification
In the second embodiment, the switching condition between normal defrosting and parallel defrosting is not limited to the switching condition of FIG. 17 based on the detected temperature Tc, but the switching condition of FIG. 19 based on the detected temperatures Tc and Two, or the detected temperature. The detailed switching conditions of FIG. 20 based on Tc and Two may be 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 each embodiment. The figure which shows the specific structure and initial stage circulation circuit of the heat-source equipment in 1st Embodiment. The figure which shows the switching conditions of the initial stage circulation circuit and tapping circuit in 1st Embodiment. The figure which shows the tapping circuit of the heat-source machine in 1st Embodiment. The figure which shows the control conditions of the pump rotation speed according to the operating frequency in each embodiment. The figure which shows the control conditions of the pump rotation speed according to the detection temperature of the outflow side temperature sensor in each embodiment. The figure which shows the control conditions of the pump rotation speed according to the condensation temperature in each embodiment. The figure which shows the control conditions of the pump rotation speed according to the discharge refrigerant | coolant temperature in each embodiment. The figure which shows the control conditions of the pump rotation speed according to the condensation temperature on the specific conditions in each embodiment. The figure which shows the control conditions of the pump rotation speed according to the discharge refrigerant | coolant temperature on the specific conditions in each embodiment. The figure which shows the control conditions of the rotation speed change rate of the pump in each embodiment. The time chart for demonstrating the up timing of the pump rotation speed in each embodiment. The figure which shows the defrost cycle and warm water circulation cycle in each embodiment. The figure which shows the switching conditions of the defrost cycle and warm water circulation cycle in each embodiment. The figure which shows the defrost cycle and warm water utilization defrost cycle in each embodiment. The figure which shows the structure of the heat-source equipment in 2nd Embodiment, and the flow of the refrigerant | coolant at the time of equilibrium defrost. The figure which shows the switching conditions of the normal defrost and parallel defrost in 2nd Embodiment. The figure which shows the flow of the refrigerant | coolant at the time of bypass interruption | blocking in 2nd Embodiment. The figure which shows the modification of the switching conditions of the normal defrost and parallel defrost in 2nd Embodiment. The figure which shows another modification of the switching conditions of normal defrost and parallel defrost in 2nd 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, 5 ... Open type tank, 7 ... Control part, 11 ... Compressor, 13 ... Water heat exchanger, 14 ... Expansion valve (pressure reducer), 15 ... outdoor heat exchanger, 21 ... first piping, 22 ... first three-way valve, 23 ... second piping, 24 ... pump, 25 ... third piping, 26 ... second 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, 41 ... discharge refrigerant temperature sensor, 42 ... high pressure Switch, 51 ... Bypass, 52 ... Two-way valve, 53 ... Flow control valve

Claims (10)

The refrigerant discharged from the compressor is passed through the water heat exchanger, decompressor, and outdoor heat exchanger, returned to the compressor, a heat pump refrigeration cycle that allows the water heat exchanger to function as a condenser, and water in the water supply side main pipe is pumped A plurality of heat source units having a water cycle that leads the hot water flowing to the water heat exchanger and flowing out of the water heat exchanger to the hot water supply side main pipe;
A first valve for controlling the flow of water between the water cycle and the water supply-side main pipe;
A second valve for controlling the circulation of hot water between the water cycle and the hot water supply side main pipe;
Equipped with a,
The first valve is a first three-way valve having a first flow path and a second flow path that can be selectively opened and closed,
The second valve is a second three-way valve having a third flow path and a fourth flow path that can be selectively opened and closed,
The water cycle of each of the heat source units is the first pipe connected from the water supply side main pipe to one end of the first flow path of the first three-way valve, and the pump from the other end of each flow path of the first three-way valve. A second pipe connected to the water inlet of the water heat exchanger via a third outlet, a third pipe connected to one end of each flow path of the second three-way valve from the water outlet of the water heat exchanger, the second A fourth pipe connected from the other end of the third flow path of the three-way valve to one end of the second flow path of the first three-way valve, and a fifth pipe connected from the middle part of the fourth pipe to the hot water supply side main pipe A pipe and a sixth pipe connected to the first pipe from the other end of the fourth flow path of the second three-way valve;
A water heater characterized by that. A heat exchanger temperature sensor for detecting the temperature of the water heat exchanger;
An inflow side temperature sensor for detecting the temperature of water flowing into the water heat exchanger;
When starting the operation of the heat source unit, the operation of the heat pump refrigeration cycle and the operation of the pump are started, and the third flow of the second three-way valve is continued until the detected temperature of each of the temperature sensors reaches a set value. The channel is closed and the fourth channel is opened, and the first channel of the first three-way valve is opened and the second channel is closed, and water is supplied to the pump, the water heat exchanger, the third pipe, A first control means for forming an initial circulation circuit that circulates through the fourth flow path of the two-way valve, the sixth pipe, the first pipe, and the first flow path of the first three-way valve;
After the initial circulation circuit is formed by the first control means, when the detected temperature of each of the temperature sensors exceeds a set value, the first flow path of the first three-way valve is opened and the second flow path is closed, And, by opening the third flow path of the second three-way valve and closing the fourth flow path, the water of the water supply side main pipe is supplied to the first pipe, the first flow path of the first three-way valve, the second Piping, sent to the water heat exchanger through the pump, and warm water flowing out from the water heat exchanger through the third pipe, the third flow path of the second three-way valve, the fourth pipe, and the fifth pipe Second control means for forming a hot water supply circuit to be sent to the hot water supply side main pipe;
The hot water supply apparatus according to claim 1 , further comprising: An outside temperature sensor for detecting the outside temperature;
An outflow temperature sensor for detecting the temperature of water flowing out of the water heat exchanger;
A discharge refrigerant temperature sensor for detecting the temperature of the discharge refrigerant of the compressor;
Third control means for setting the rotational speed at the start of operation of the pump according to the detected temperature of the outside air temperature sensor;
The number of rotations of the pump set by the third control means is set such that when the detected temperature of the inflow side temperature sensor is less than a predetermined value, the operating frequency of the compressor, the detected temperature of the outflow side temperature sensor, the heat exchange When the detected temperature of the inflow side temperature sensor is equal to or higher than a predetermined value, the detected temperature of the heat exchanger temperature sensor and the discharge temperature are corrected. Fourth control means for correcting increase / decrease according to the detected temperature of the refrigerant temperature sensor;
Fifth control means for switching the rate of change of the rotation speed of the pump in accordance with the detected temperature of the heat exchanger temperature sensor when the increase direction is corrected by the fourth control means;
The hot water supply apparatus according to claim 2 , further comprising: Sixth control means for delaying the start of operation of the heat pump refrigeration cycle by the first control means by a fixed time;
The hot water supply apparatus according to claim 2 , further comprising: An outflow temperature sensor for detecting the temperature of water flowing out of the water heat exchanger;
When stopping the operation of the heat source unit, first, the operation of the heat pump refrigeration cycle is stopped, and the second control unit continues the operation of the pump until the temperature detected by the outflow side temperature sensor decreases to a constant value. A seventh control means for continuing the formation of the tapping circuit;
After stopping the operation of the heat pump refrigeration cycle by the seventh control means, when the detected temperature of the outflow side temperature sensor falls below a certain value, the operation of the pump is stopped and the third flow path of the second three-way valve is stopped. An eighth control means for releasing the formation of the tapping circuit by closing and opening the fourth flow path, and opening the first flow path of the first three-way valve and closing the second flow path;
The hot water supply apparatus according to claim 2 , further comprising: Ninth control means for increasing the number of revolutions of the pump to the number of revolutions for pouring hot water in a state in which the initial circulation circuit is formed by the first control means before the tapping circuit is formed by the second control means. ,
The hot water supply apparatus according to claim 2 , further comprising: Upon defrosting the outdoor heat exchanger, the operation of the compressor is temporarily stopped, the third flow path of the second three-way valve is opened, the fourth flow path is closed, and the first three-way valve By closing one flow path and opening the second flow path, the hot water flows into the hydrothermal exchanger, the third pipe, the third flow path of the second three-way valve, the fourth pipe, and the first three-way valve. A tenth control means for forming a second flow path, a hot water circulation circuit circulating through the pump;
After the hot water circulation circuit is formed by the tenth control means, the operation of the compressor is resumed and the refrigerant discharged from the compressor returns to the compressor through the outdoor heat exchanger, the decompressor, and the water heat exchanger. Eleventh control means for forming a cycle;
After the defrost cycle is formed by the eleventh control means, the first flow path of the first three-way valve is closed to open the second flow path, and the third flow path of the second three-way valve is closed to close the fourth flow path. The hot water in the hot water supply side main pipe flows to the water heat exchanger through the fifth pipe, the fourth pipe, the second flow path of the first three-way valve, the pump, and the water heat The water that has passed through the exchanger forms a hot water defrosting circuit that flows through the third pipe, the fourth flow path of the second three-way valve, the sixth pipe, and the first pipe to the water supply side main pipe. 12 control means;
The hot water supply apparatus according to claim 2 , further comprising: An outflow temperature sensor for detecting the temperature of water flowing out of the water heat exchanger;
After the formation of the hot water defrosting circuit by the twelfth control means, when the detected temperature of the outflow side temperature sensor rises above a predetermined value, the hot water defrosting circuit is switched to the formation of the hot water circulation circuit by the tenth control means, A thirteenth control means for switching from the hot water circulation circuit to the formation of a hot water defrosting circuit by the twelfth control means when the temperature detected by the outflow side temperature sensor falls below a predetermined value;
The hot water supply apparatus according to claim 7 , further comprising: An outflow temperature sensor for detecting the temperature of water flowing out of the water heat exchanger;
A bypass connected in parallel to the water heat exchanger in the refrigerant flow path of the heat pump refrigeration cycle;
A two-way valve provided in the bypass;
When forming the defrosting circuit using hot water by the twelfth control means, the two-way valve is closed when the detected temperature of any one of the temperature sensors becomes equal to or higher than a predetermined value, and the two-way when the detected temperature becomes lower than the predetermined value. 14th control means for opening the valve;
The hot water supply apparatus according to claim 7 , further comprising: A flow rate adjustment valve provided on the water heat exchanger side of the bypass connection position in the refrigerant flow path between the water heat exchanger and the decompressor of the heat pump refrigeration cycle;
Fifteenth control means for controlling the opening degree of the flow rate adjusting valve in a direction to be narrowed as the detected temperature of each of the temperature sensors is lower when the two-way valve is opened by the fourteenth control means;
The hot water supply apparatus according to claim 9 , further comprising:

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