JP2008261590A - Ejector cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To specify a cause of failure by troubleshooting of an ejector and an expansion valve in an ejector cycle. <P>SOLUTION: In an ejector cycle, when the temperature difference between an inlet side refrigerant temperature and an outlet side refrigerant temperature of a second evaporator 8 is a predetermined value or more in the case of totally closing the throttle opening of the expansion valve 7, a throttle means 7 is determined to be in an abnormal state in opening. When a pressure sensor 37 for detecting high pressure side pressure between the ejector 5 and the throttle means 7 from a compressor 3 is in a high pressure state of a predetermined pressure or higher in the case of totally closing the throttle opening of the throttle means 7 and opening the passage opening of a nozzle part 50 of the ejector 5, the ejector 5 is determined to be in an abnormal state in total closing. When the high pressure side pressure is a predetermined pressure or higher in the case of totally closing the passage opening of the nozzle part 50 of the ejector 5 and opening the throttle opening of the throttle means 5, the throttle means 7 is determined to be in an abnormal state in total closing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ejector cycle including an ejector that serves as a refrigerant decompression unit and a refrigerant circulation unit, and is effective for use in a water heater.

  The flow of the refrigerant is branched at a branching portion on the downstream side of the radiator and upstream of the nozzle portion of the ejector, one branched refrigerant flows into the nozzle portion side of the ejector, and the other refrigerant flows to the refrigerant suction port side of the ejector. Patent Document 1 discloses an ejector cycle to be introduced.

In the ejector cycle of Patent Document 1, a first evaporator is disposed on the downstream side of an ejector from which ejector inflow refrigerant flows out, and a throttling mechanism for depressurizing the refrigerant between a branch portion and a refrigerant suction port of the ejector, and a refrigerant And a second evaporator that evaporates and flows out to the upstream side of the refrigerant suction port of the ejector. For this reason, the throttle mechanism and the ejector are arranged in parallel by the branch portion provided on the downstream side of the radiator.
JP 2005-308380 A

  However, in the ejector cycle of Patent Document 1, if either the ejector or the throttle mechanism fails due to some cause, the throttle mechanism and the ejector are arranged in parallel, so that the capacity of the radiator or the like is abnormal or the pressure in the cycle is abnormal. May occur. In this case, there is a problem that it is impossible to specify which of the diaphragm mechanism and the ejector has the cause of the failure.

  An object of this invention is to perform the failure diagnosis process of an ejector and an expansion valve in an ejector cycle in view of the said point, and to specify the cause of a failure.

  In order to achieve the above object, in the present invention, a compressor (3) that sucks and compresses a refrigerant, a radiator (4) that radiates high-pressure refrigerant discharged from the compressor (3), and a radiator (4 ) And a gas phase refrigerant suction port (51) through which the gas phase refrigerant is sucked into the interior by a high-speed refrigerant flow injected from the nozzle portion (50), Ejector (5) having a booster (53) for converting the velocity energy of the refrigerant flow mixed with the high-speed refrigerant flow and the gas-phase refrigerant into pressure energy, and evaporating the refrigerant flowing out of ejector (5) The refrigerant flow is branched between the first evaporator (6) whose refrigerant outlet is connected to the suction side of the compressor (3), the radiator (4) and the ejector (5). A branch passage (22) leading to the gas-phase refrigerant suction port (51); A throttle means (7) disposed in the branch passage (22) and capable of reducing the refrigerant in the branch passage (22) and closing the branch passage (22) by fully closing the throttle opening; The second evaporator (8) disposed downstream of the throttle means (7) in the passage (22) and evaporating the refrigerant decompressed by the throttle means (7), and the throttle opening degree of the throttle means (7) are controlled. A throttle opening degree control means, a first temperature detection means (32) for detecting a refrigerant temperature downstream of the throttle means (7) and upstream of the second evaporator (8), and a second evaporator ( 8) the second temperature detecting means (33) for detecting the refrigerant temperature downstream of the refrigerant suction port (51), and the throttle opening degree of the throttle means (7) by the throttle opening degree control means. When the control for closing is performed, the cooling detected by the first temperature detection means (32) is performed. When the difference between the temperature and the refrigerant temperature detected by the second temperature detection means (33) is larger than a predetermined value, the throttle means (7) determines that the throttle opening is in an abnormal open state where the throttle opening cannot be fully closed. An abnormality determining means is provided as a first feature.

  Thus, when the throttle opening of the expansion valve (7) is fully closed, the refrigerant temperature detected by the first temperature detection means (32) arranged on the inlet side of the second evaporator (8) and the outlet side When the temperature difference from the refrigerant temperature detected by the second temperature detecting means (33) arranged in the position is greater than or equal to a predetermined value, it is determined that the throttle means (7) is in an open abnormal state, so that in the ejector cycle It can be identified as the cause of the failure of the throttle means (7).

  Further, in the ejector cycle having the first feature, when the abnormality determining means determines that the opening is abnormal, the ejector opening that increases the passage opening degree of the nozzle portion (50) of the ejector (5) than that at the time of determination. When it is provided with at least one of rotation speed control means for increasing the rotation speed of the compressor (3) when it is determined to be in an open abnormal state by the degree control means or the abnormality determination means, the compressor (3) Therefore, an alternative operation for increasing the high-pressure side pressure between the ejector (5) and the throttle means (7) can be executed.

  In the ejector cycle having the first feature, the ejector opening degree control means for controlling the passage opening degree of the nozzle portion (50), the downstream side of the compressor (3) and the upstream side of the ejector (5). Pressure detecting means (37) for detecting the pressure of the refrigerant, the throttle opening degree control means controls the throttle opening degree of the throttle means (7) to be fully closed, and the ejector opening degree control means controls the nozzle. When the control is performed to open the passage opening of the part (50), the abnormality determining means does not determine that the opening is abnormal, and the pressure detected by the pressure detecting means is greater than a predetermined value. In this case, it is determined that the ejector (5) is in a fully closed abnormal state where the opening degree of the passage of the nozzle portion (50) cannot be opened, thereby causing the failure of the throttle means (7) and the ejector (5) in the ejector cycle. It can be identified.

  According to this, when the throttle opening of the throttle means (7) is fully closed and the passage opening of the nozzle (50) of the ejector (5) is opened, the first temperature detection means (32) When the difference between the detected refrigerant temperature and the refrigerant temperature detected by the second temperature detection means (33) is larger than a predetermined value, it can be determined that the throttling means (7) is in an abnormal open state. . When the pressure detection means (37) for detecting the high pressure side pressure between the compressor (3) and the ejector (5) and the throttle means (7) is in a high pressure state higher than a predetermined pressure, the ejector (5) Can be determined to be in the fully-closed abnormal state, the failure diagnosis processing of the ejector cycle throttling means (7) and the ejector (5) is performed to identify the cause of failure of the ejector (5) in the ejector cycle. be able to.

  In the present invention, the compressor (3) that sucks and compresses the refrigerant, the radiator (4) that radiates heat of the high-pressure refrigerant discharged from the compressor, and the refrigerant on the downstream side of the radiator (4) is decompressed. A nozzle part (50) to be expanded, a gas-phase refrigerant suction port (51) into which gas-phase refrigerant is sucked in by a high-speed refrigerant flow ejected from the nozzle part (50), a high-speed refrigerant flow and a gas phase The ejector (5) having a booster (53) for converting the velocity energy of the refrigerant flow mixed with the refrigerant into pressure energy, evaporates the refrigerant flowing out from the ejector (5), and the refrigerant outflow side is connected to the compressor (3 ), The refrigerant flow is branched between the first evaporator (6) connected to the suction side, the radiator (4), and the ejector (5), and this refrigerant flow is divided into the gas-phase refrigerant suction port (51). A branch passage (22) leading to a branch passage (22) The throttle means (7) that can close the branch path (22) by reducing the refrigerant in the branch path (22) and making the throttle opening fully closed, and the throttle means (7) in the branch path (22) A second evaporator (8) disposed on the downstream side of 7) for evaporating the refrigerant decompressed by the throttle means (7), a throttle opening degree control means for controlling the throttle opening degree of the throttle means (7), Ejector opening degree control means for controlling the passage opening degree of the nozzle part (50), and pressure detection means (37) for detecting the pressure of the refrigerant downstream of the compressor (3) and upstream of the ejector (5). And a control for making the throttle opening of the throttle means (7) fully closed by the throttle opening control means, and a control for opening the passage opening of the nozzle section (50) by the ejector opening control means. Detected by the pressure detection means. And an abnormality determining means for determining that the ejector (5) is in a fully-closed abnormal state where the passage opening of the nozzle portion (50) cannot be opened when the pressure is greater than a predetermined value. It is characterized by.

  Thus, when the throttle opening of the throttle means (7) is fully closed and the passage opening of the nozzle (50) of the ejector (5) is opened, the compressor (3) to the ejector (5) and When the pressure detection means (37) for detecting the high-pressure side pressure between the throttle means (7) is in a high pressure state higher than a predetermined pressure, it can be determined that the ejector (5) is in a fully closed abnormal state. Therefore, it can be identified as the cause of failure of the ejector (5) in the ejector cycle.

  In the ejector cycle of the second feature, when the throttle opening degree control means increases the opening degree of the throttle means (7) more than at the time of determination when the abnormality determination means determines that it is in the fully closed abnormal state. An alternative operation for lowering the high-pressure side pressure between the compressor (3) and the ejector (5) and the throttle means (7) can be executed.

  In the present invention, the compressor (3) that sucks and compresses the refrigerant, the radiator (4) that radiates heat of the high-pressure refrigerant discharged from the compressor, and the refrigerant on the downstream side of the radiator (4) is decompressed. A nozzle part (50) to be expanded, a gas-phase refrigerant suction port (51) into which gas-phase refrigerant is sucked in by a high-speed refrigerant flow ejected from the nozzle part (50), a high-speed refrigerant flow and a gas phase The ejector (5) having a booster (53) for converting the velocity energy of the refrigerant flow mixed with the refrigerant into pressure energy, evaporates the refrigerant flowing out from the ejector (5), and the refrigerant outflow side is connected to the compressor (3 ), The refrigerant flow is branched between the first evaporator (6) connected to the suction side, the radiator (4), and the ejector (5), and this refrigerant flow is divided into the gas-phase refrigerant suction port (51). A branch passage (22) leading to a branch passage (22) The throttle means (7) that can close the branch path (22) by reducing the refrigerant in the branch path (22) and making the throttle opening fully closed, and the throttle means (7) in the branch path (22) A second evaporator (8) disposed downstream of 7) for evaporating the refrigerant decompressed by the throttle means (7), a throttle opening degree control means for controlling the throttle opening degree of the throttle means (7), An ejector opening degree control means for controlling the opening degree of the passage of the nozzle part (50) and controlling the refrigerant passage of the nozzle part (50) to be fully closed, and an ejector on the downstream side of the compressor (3) The pressure detection means (37) for detecting the pressure of the refrigerant on the upstream side of (5) and the ejector opening degree control means control the passage opening degree of the nozzle portion (50) to be fully closed, and the throttle opening The throttle opening degree of the throttle means (7) is controlled by the degree control means. In the case where the control for setting the state is performed, if the pressure detected by the pressure detecting means (37) is larger than a predetermined value, the throttle means (7) is in a fully closed abnormal state where the throttle opening cannot be opened. A third feature is that it comprises an abnormality determining means for determining.

  Thus, when the passage opening of the ejector (5) nozzle section (50) is fully closed and the throttle opening of the throttle means (5) is opened, the compressor (3) to the ejector (5) and When the pressure detection means (37) for detecting the high-pressure side pressure between the throttle means (7) is in a high pressure state higher than a predetermined pressure, it can be determined that the throttle means (7) is in a fully closed abnormal state. Therefore, it can be identified as the cause of the failure of the throttle means (7) in the ejector cycle.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a conceptual diagram of an overall configuration in which an ejector cycle according to a first embodiment of the present invention is applied to a water heater 1. As shown in FIG. 1, the water heater 1 according to the present embodiment includes a hot water storage tank 11 that stores hot water, an ejector cycle 2 that heats the hot water, and a water circulation passage 23 that can circulate hot water in the hot water tank 11. It has. The water circulation passage 23 is provided with a water supply pump 12 for circulating hot water.

  The water storage tank 11 is arranged so that the right side in FIG. 1 is the upper side and the left side is the lower side, and is configured to flow in hot water from the upper side of the water storage tank 11 and flow out hot water from the lower side. The hot water flows from the outlet part below the hot water tank 11 to the inlet part above the hot water tank 11, as indicated by the arrow in the figure.

The ejector cycle 2 includes a refrigerant circulation passage 20 through which the refrigerant circulates. In the present embodiment, CO ₂ having a high pressure equal to or higher than the critical pressure (supercritical state) is used as the refrigerant.

  A compressor 3 that sucks and compresses the refrigerant is disposed in the refrigerant circulation passage 20. The compressor 3 is an electric compressor that is driven by a built-in electric motor, and compresses and discharges the suction refrigerant to a critical pressure or higher.

  A water refrigerant heat exchanger 4 is disposed on the downstream side of the refrigerant flow of the compressor 3. The water refrigerant heat exchanger 4 heats the hot water by exchanging heat between the refrigerant discharged from the compressor 3 (high temperature and high pressure refrigerant) and the hot water in the water circulation passage 23.

  The water-refrigerant heat exchanger 4 has a water passage 24 through which hot water flows in the water circulation passage 23 and a refrigerant passage 21 through which compressor discharge refrigerant flows in the refrigerant circulation passage 20, and the flow direction of hot water flowing through the water passage 24. And the flow direction of the refrigerant flowing through the refrigerant passage 21 are opposed to each other.

Incidentally, the refrigerant (CO ₂₎ flowing through the water-refrigerant heat exchanger 4, by in the compressor 3 is compressed to critical pressure or higher so that the heat radiation remains hot water in a supercritical state, does not condense.

  An ejector 5 is arranged on the downstream side of the refrigerant flow of the water refrigerant heat exchanger 4. The ejector 5 is a decompression unit that decompresses the refrigerant, and is also a refrigerant circulation unit that circulates the refrigerant by suction of a refrigerant flow ejected at high speed.

  The ejector 5 includes a nozzle unit 50 for reducing the passage area of the high-pressure refrigerant (high-pressure saturated liquid refrigerant) flowing in from the water-refrigerant heat exchanger 4 to a low pressure and expanding the high-pressure refrigerant in an isentropic manner. A refrigerant suction port 51 that is disposed so as to communicate with the refrigerant outlet and sucks a refrigerant (gas phase refrigerant) from a second evaporator outlet 8 described later is provided.

  A mixing unit 52 that mixes the high-speed refrigerant flow from the nozzle unit 50 and the suction refrigerant from the refrigerant suction port 51 is provided downstream of the nozzle unit 50 and the refrigerant suction port 51. A diffuser portion 53 that forms a boosting portion is disposed downstream of the mixing portion 52. The diffuser portion 53 is formed in a shape that gradually increases the passage area of the refrigerant, and functions to increase the refrigerant pressure by decelerating the refrigerant flow, that is, to convert the velocity energy of the refrigerant into pressure energy.

  Furthermore, a variable needle 54 whose position is controlled by an electric actuator is disposed in the nozzle unit 50. By controlling the position of the variable needle 54, the passage opening degree of the nozzle unit 50 can be electrically controlled and the nozzle unit 50 is fully closed. You can do it.

  The first evaporator 6 is connected to the outlet side of the diffuser portion 53 of the ejector 5. The first evaporator 6 absorbs and evaporates the low-pressure refrigerant decompressed by the ejector 5 from the outside air (outdoor air).

  The outlet side of the first evaporator 6 is connected to the suction side of the accumulator 10. The accumulator 10 is a gas-liquid separator that gas-liquid separates the refrigerant flowing out from the first evaporator 6. The accumulator 10 sucks only the gas-phase refrigerant into the compressor 3 and uses the excess refrigerant in the ejector cycle 2 as the liquid-phase refrigerant. store.

  Further, in the ejector cycle 2 of the present embodiment, a branch is made at a portion of the refrigerant circulation passage 20 between the water refrigerant heat exchanger 4 and the ejector 5, and merges with the refrigerant circulation passage 20 at the refrigerant suction port 51 of the ejector 5. A branch passage 22 is formed.

  An expansion valve 7 that adjusts the flow rate of the refrigerant and depressurizes the refrigerant is disposed in the branch passage 22. A second evaporator 8 is disposed at a downstream side of the refrigerant flow with respect to the expansion valve 7. Here, the expansion valve 7 corresponds to the throttle means in the present invention.

  The expansion valve 7 is a pressure reducing means that adjusts the refrigerant flow rate to the second evaporator 8, and specifically, the passage throttle opening (valve opening) can be controlled by an electric actuator as a variable throttle. At the same time, the passage throttle opening can be fully closed.

  The first evaporator 6 and the second evaporator 8 are outdoor heat exchangers that absorb and evaporate the low-pressure refrigerant (gas-liquid two-phase refrigerant) decompressed by the expansion valve 7 from the outside air (outdoor air). The first evaporator 6 and the second evaporator 8 are blown by the outdoor fan 9.

  Moreover, the water heater 1 of this embodiment is provided with the control apparatus 100, and the control apparatus 100 is comprised from the well-known microcomputer containing CPU, ROM, RAM, etc. and its peripheral circuit. Based on the output signals of the sensor group, the control device 100 performs the electrical equipment of the water heater 1, that is, the water supply pump 12, the electric motor of the compressor 3, the actuator of the variable needle 54, the actuator of the expansion valve 7, and the outdoor fan 9. Control the operation of etc. Note that the control device 100 of the present embodiment is supplied with power from a commercial power source.

  A sensor detection signal is input from the hot water supply sensor group to the input side of the control device 100, and operation signals are input from various hot water supply operation switches provided on the operation panel 38.

  The sensor group includes a refrigerant discharge temperature sensor 30, a refrigerant temperature sensor 31, an evaporator inlet side temperature sensor 32, an evaporator outlet side temperature sensor 33, an outside air temperature sensor 34, a water supply temperature sensor 35, a hot water supply temperature sensor 36, and a pressure sensor. 37. Here, the evaporator inlet side temperature sensor 32 corresponds to the first temperature detecting means in the present invention, and the evaporator outlet side temperature sensor 33 corresponds to the second temperature detecting means in the present invention. The pressure sensor 37 corresponds to the pressure detection means in the present invention.

  The refrigerant temperature sensor 31 is a sensor that detects the refrigerant temperature on the outlet side of the water refrigerant heat exchanger 4, and the refrigerant discharge temperature sensor 30 is downstream of the compressor 3 and upstream of the water refrigerant heat exchanger 4. Is a sensor that detects the refrigerant temperature on the inlet side of the water refrigerant heat exchanger 4. The evaporator inlet side temperature sensor 32 is a sensor that detects the refrigerant temperature on the inlet side of the second evaporator 8, and the evaporator outlet side temperature sensor 33 detects the refrigerant temperature on the outlet side of the second evaporator 8. It is a sensor. The outside air temperature sensor 34 is disposed in the vicinity of the outdoor fan 9 and detects the outside air temperature. The water supply temperature sensor 35 is a sensor that detects the water temperature on the inlet side of the water passage 24 of the water refrigerant heat exchanger 4, and the hot water supply temperature sensor 36 is the water temperature on the outlet side of the water passage 24 of the water refrigerant heat exchanger 4. It is a sensor to detect. The pressure sensor 37 is a sensor that is disposed downstream of the water-refrigerant heat exchanger 4 and upstream of the branch passage 22 and detects the pressure on the high-pressure side downstream of the compressor 3.

  The operation panel 38 includes a display panel such as a liquid crystal panel, and a switch for setting an operation and a stop operation of the water heater, a target water temperature Tp of the water heater, and the like.

  Next, the operation of this embodiment will be described with reference to FIGS. FIG. 2 shows the overall control processing executed by the control device 100 according to this embodiment. This control process is started by an operation signal of the water heater 1 input from the operation panel 38.

  First, initialization processing of each control variable, each timer, etc. is performed in S101. Here, the timer indicates an operation time measurement timer used in an abnormality determination process described later and a failure diagnosis timer used in the failure diagnosis process.

  After initialization, the feed water temperature sensor 35, the hot water temperature sensor 36, the refrigerant temperature sensor 31, the refrigerant discharge temperature sensor 30, the evaporator inlet side temperature sensor 32, the evaporator outlet side temperature sensor 33, and the outside air temperature sensor 34 are sent out in S102. Input processing of each output to be performed. In addition, the boiling target temperature Tp (for example, 90 ° C.) of hot water in the water heater 1 is read from the switch of the operation panel 38, and the boiling reference time Tu corresponding to the boiling target temperature Tp is determined by the control device 100. Read from ROM.

  Here, the boiling reference time Tu of the rising time is from the start of the boiling operation (that is, the heating operation) until the boiling temperature (detected temperature of the hot water supply temperature sensor 36) reaches the boiling target temperature Tp. This is reference time data for the time spent, and is used in an abnormality determination process to be described later. The boiling reference time Tu is stored in advance in the ROM of the control device 100 or the like. The boiling reference time Tu is set so as to be determined by the outside air temperature, the feed water temperature, and the boiling target temperature Tp.

Next, in S103, it is determined whether or not a request for executing the boiling operation is made.
The request to execute the boiling operation is made based on a manual operation from the operation panel 38 by the user or a boiling control program for executing automatic boiling. The boiling-up control program is stored in advance in the ROM or the like of the control device 100. Here, in the determination process of the boiling operation, in order to bring the water supply temperature of the hot water storage tank 11 close to the target water supply temperature Tp (for example, 90 ° C.), the actuators of the compressor 3, the water supply pump 12, the outdoor fan 9 and the like are controlled. This is a process for determining necessity, and is a well-known determination (see Japanese Patent Application Laid-Open No. 2002-213816).

  If the boiling operation is not performed as a result of the determination process in S103, the process proceeds to S104, and a stop control process for stopping all the operations of the water supply pump 12, the outdoor fan 9, the compressor 3, and the like is performed.

  On the other hand, when performing a boiling operation, a valve opening degree determination process is performed by S105. In the valve opening determination processing, the target opening of the throttle opening of the expansion valve 7 and the passage opening of the nozzle portion 50 of the ejector 5 is determined so that the boiling temperature of the hot water supply becomes the boiling target temperature. However, when performing a failure diagnosis process described later, the target opening is determined based on the throttle opening set in the failure diagnosis process.

  Next, a feed pump flow rate determination process is performed in S106. In the feed water pump flow rate determination process, the target flow rate of the feed water pump 12 is determined so that the boiling temperature of the hot water supply becomes the boiling target temperature.

  Next, fan rotation speed determination processing is performed in S107. In the fan rotation speed determination process, the target rotation speed of the outdoor fan 9 is determined so that the boiling temperature of the hot water supply becomes the boiling target temperature.

  Next, compressor speed determination processing is performed in S108. In the compressor rotational speed determination process, the target rotational speed of the compressor 3 is determined. In the compressor rotational speed determination process, the target rotational speed is determined so that the rotational speed increases as the outside air temperature decreases, and the target rotational speed is determined such that the rotational speed decreases as the outdoor air temperature increases. Also, if the boiling temperature of the hot water does not reach the boiling target temperature, the target rotational speed is determined to increase, and if the boiling temperature of the hot water is too high, the rotational speed is decreased. Determine the target speed.

  Next, based on the target values determined in each process, the output values of the expansion valve 7, the ejector 5, the feed water pump 12, the outdoor fan 9, and the compressor 3 are output in S109, and the throttle opening of the expansion valve 7 is controlled. And the actuator of the variable needle 53 that controls the opening degree of the passage of the nozzle portion 50 of the ejector 5 are controlled.

  After the output process is completed, an abnormality determination process is performed to determine whether or not an abnormality has occurred in the heating capacity of the water heater 1 in S110.

  Next, the detailed content of the abnormality determination process of the water heater 1 will be described with reference to FIG. FIG. 3 shows a flowchart of the abnormality determination process. In this embodiment, the heating capacity of the water heater 1 is divided into four stages of A rank, B rank, C rank, and D rank in descending order. Here, in the present embodiment, rank A and rank B are not subjected to failure diagnosis processing, which will be described later, assuming that the heating capacity of the water heater 1 is a normal rank. In addition, the rank C and the rank D are subjected to a failure diagnosis process, which will be described later, assuming that the heating capability of the water heater 1 is an abnormal rank.

  First, in S201, the measurement of the operation time Ton of the boiling operation is started using the operation time measurement timer. Next, in S202, it is determined whether or not the boiling temperature (detected temperature of the hot water supply temperature sensor 36) has reached the boiling target temperature Tp. In S202, when the boiling temperature of the hot water has reached the boiling target temperature Tp, the process proceeds to S204.

  In S202, when the boiling temperature of the hot water is lower than the boiling target temperature Tp, the process proceeds to S203.

  In S203, it is determined whether or not the boiling operation time Ton measured by the operation time measurement timer has passed a measurement upper limit time (for example, 2 hours). Here, the measurement upper limit time indicates the upper limit time for measuring the heating capacity of the boiling operation determined based on the boiling reference time Tu. In addition, the measurement upper limit time in the present embodiment is set to a time shorter than the boiling reference time Tu, which is equal to or longer than the boiling reference time Tu.

  As a result of the determination, when the boiling operation time Ton has passed the measurement upper limit time (boiling operation time Ton ≧ measurement upper limit time), the process proceeds to S204.

  In S204, it is determined whether or not the boiling operation time Ton is longer than a time obtained by doubling the boiling reference time Tu. If it is determined in S204 that the boiling operation time Ton is shorter than the time obtained by doubling the boiling reference time Tu, the process proceeds to S205.

  In S205, it is determined that “A rank (specifically, the heating capacity is in a normal range)”, and “A rank (normal range)” is recorded in the RAM or the like of the control device 100. Thereafter, the process returns to the entire control process.

  If it is determined in S204 that the boiling operation time Ton is longer than the time obtained by doubling the boiling reference time Tu, the process proceeds to S206. In S206, it is determined whether or not the boiling operation time Ton is longer than the time obtained by triple the boiling reference time Tu, and it is determined that the boiling operation time Ton is shorter than the time obtained by triple the boiling reference time Tu. If so, the process proceeds to S207.

  In S207, it is determined as “B rank (specifically, the heating ability is likely to be reduced)”, and “B rank” is recorded in the RAM or the like of the control device 100. Thereafter, the process returns to the entire control process.

  Furthermore, in S207, when it is determined that the boiling operation time Ton is longer than the time obtained by triple the boiling reference time Tu, the process proceeds to S208. In S208, it is determined that “C rank (specifically, a level that requires replacement)”, and the fact that it is “C rank” is recorded in the RAM or the like of the control device 100. Thereafter, the process proceeds to the failure diagnosis process of S212.

  In S203 described above, when the boiling operation time Ton measured by the operation time measurement timer is shorter than the measurement upper limit time, the process proceeds to S209.

  In S209, it is determined whether or not the boiling operation time Ton is longer than the abnormality determination time Tng. When the boiling operation time Ton is longer than the abnormality determination time Tng in S209 (Ton> Tng), it is determined that the boiling operation time Ton is abnormally long, and the process proceeds to S210.

  In S210, it is determined whether or not the current detected temperature Two (boiling temperature) of the hot water supply temperature sensor 36 is lower than the abnormal reference temperature Ts. In S210, when the boiling temperature Two (boiling temperature) is lower than the abnormal reference temperature Ts (Two <Ts), it is determined that the boiling temperature Two is abnormally low and the process proceeds to S211.

  In S211, “D rank (abnormal state)” is determined, and “abnormal state” is recorded in the RAM or the like of the control device 100. Thereafter, the process proceeds to the failure diagnosis process of S212.

  In this way, it is determined whether the heating capacity of the water heater 1 corresponds to rank A to rank D, and the determination result is stored in the RAM or the like of the control device 100. If the determination result is rank C or rank D, a failure diagnosis process in S212 described later is performed. After executing the failure diagnosis process in S212, the process returns to the overall control process.

  In S209 described above, when the boiling operation time Ton is shorter than the abnormality determination time Tng (Ton ≦ Tng), and in S210, the current detection temperature Two (boiling temperature) of the hot water supply temperature sensor 36 is an abnormality reference. When the temperature is higher than the temperature Ts (Two ≧ Ts), it returns to the entire control process as being in a normal operation state.

  Next, the detailed content of the failure diagnosis process of the water heater 1 will be described with reference to FIG. FIG. 4 shows a flowchart of the failure diagnosis process.

  In the present embodiment, the abnormality determination processing result is normal or minor abnormality for the A rank and B rank, so the failure diagnosis processing is not performed, and the abnormality determination processing result is the abnormal state for the C rank and D rank. Therefore, failure diagnosis processing is performed.

  In the present embodiment, failure diagnosis processing is performed in an abnormal open state where the throttle opening of the expansion valve 7 provided in the branch passage 22 of the refrigerant circulation passage 20 cannot be fully closed. Here, the abnormal opening state of the expansion valve 7 refers to an expansion valve when the controller 100 controls the throttle opening of the expansion valve 7 to instruct the throttle opening to be fully closed. 7 indicates that the throttle opening cannot be fully closed, that is, the throttle is open regardless of the size of the throttle opening.

  First, in S301, when the result of the abnormality determination process (the process shown in FIG. 3) is C rank or D rank, it is determined whether or not the failure diagnosis mode has been started. Here, whether or not the failure diagnosis mode has started is determined by whether or not the failure diagnosis timer is operating. Here, the failure diagnosis timer is for measuring an elapsed time after setting the target opening of the expansion valve 7 to the fully closed state in S302 described later.

  If it is determined in S301 that the failure diagnosis mode has not been started, the process proceeds to S302, where the target opening of the throttle opening of the expansion valve 7 is set to a fully closed state. At the same time, the failure diagnosis timer is operated to measure the time elapsed since the target opening of the throttle opening of the expansion valve 7 is set to the fully closed state.

  If it is determined in S301 that the failure diagnosis mode has been started, it is determined in S303 whether or not the time measured by the failure diagnosis timer has passed a predetermined time (for example, 10 minutes). Here, the reason for allowing the predetermined time to elapse is to stabilize the ejector cycle 2 by allowing the predetermined time to elapse after the throttle opening of the expansion valve 7 is fully closed.

  If it is determined in S303 that the time measured by the failure diagnosis timer has not passed the predetermined time, the abnormality determination process (the process of FIG. 3) is performed while the target opening of the throttle opening of the expansion valve 7 is set to the fully closed state. Return to).

  If it is determined in S303 that the time measured by the failure diagnosis timer has passed the predetermined time, the process proceeds to S304. In S304, the refrigerant temperature detected by the evaporator inlet-side temperature sensor 32 arranged on the inlet side of the second evaporator 8 and the refrigerant temperature detected by the evaporator outlet-side temperature sensor 33 arranged on the outlet side. It is determined whether or not the temperature difference (second evaporator refrigerant temperature difference) is within a predetermined error range (for example, 2 ° C.).

  The determination shown in S304 will be described with reference to FIG. FIG. 5 shows the relationship between the elapsed time from the instruction to fully close the expansion valve 7 and the second evaporator refrigerant temperature difference. Here, the solid line in the figure indicates that the expansion valve 7 is in an abnormal open state, and the dashed line indicates that the expansion valve 7 is in a normal state. A dotted line indicates a predetermined temperature difference and a predetermined time. Further, the range larger than the predetermined temperature difference after the lapse of a predetermined time is defined as an abnormal range of the expansion valve 7, and the range smaller than the predetermined temperature difference after the lapse of the predetermined time is defined as a normal range of the expansion valve 7.

  As shown in FIG. 5, the second evaporator refrigerant temperature difference after the lapse of a predetermined time is stable within the range of the predetermined temperature difference when the throttle opening of the expansion valve 7 is in a fully closed state (one-dot broken line in the figure). . However, unless the throttle opening of the expansion valve 7 is in the fully closed state, the value is stabilized at a value exceeding the predetermined temperature difference range (solid line in the figure).

  Thereby, since the throttle opening degree of the expansion valve 7 disposed on the upstream side of the second evaporator 8 in the branch passage 22 is fully closed, the refrigerant does not flow into the second evaporator 8. The refrigerant temperature difference becomes almost zero. Therefore, conversely, if the second evaporator refrigerant temperature difference is outside the range of error or the like, the refrigerant is flowing into the second evaporator 8, and therefore it is determined that the expansion valve 7 is in an abnormal open state. Can do.

  Returning to FIG. 4, if the second evaporator refrigerant temperature difference is greater than or equal to the predetermined temperature difference in S304, it is determined in S305 that the expansion valve 7 is in an abnormal open state, and the expansion valve 7 is opened in the RAM or the like of the control device 100. Record the abnormal condition. If the second evaporator refrigerant temperature difference is smaller than the predetermined temperature difference in S304, it is determined in S306 that the expansion valve 7 is in a normal state in which the throttle opening can be fully closed, and the normal state is stored in the RAM or the like of the control device 100. It records that it is.

  As described above, when the throttle opening of the expansion valve 7 is fully closed based on the result of the abnormality determination process, if the second evaporator refrigerant temperature difference is out of the error range, the expansion valve 7 is opened. By determining that the state is abnormal, it can be identified as the cause of the failure of the expansion valve 7 of the water heater 1.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, only the parts different from the first embodiment will be described.

  In the present embodiment, an alternative operation of the water heater 1 will be described when it is determined in the failure diagnosis process of the first embodiment that the throttle opening of the expansion valve 7 is in an abnormal open state where the expansion valve 7 cannot be fully closed.

  The purpose of the alternative operation in the present embodiment is to make up for a lack of heating capacity of the water heater 1 that occurs due to an abnormal open state of the expansion valve 7. Here, the reason for the insufficient heating capacity is that the expansion valve 7 is always open in the abnormal opening state of the expansion valve 7, so that the high pressure side pressure between the compressor 3 and the ejector 5 and the expansion valve 7 is the target pressure. This is because the hot water in the water passage 24 cannot be sufficiently heated in the water / refrigerant heat exchanger 4.

  Therefore, in this embodiment, the shortage of the heating capacity of the water heater 1 is compensated by executing an alternative operation in the valve opening degree determination process shown in S105 of FIG.

  The valve opening determination process in the case of performing an alternative operation will be described with reference to FIG. FIG. 6 shows a flowchart of the valve opening degree determination process when the expansion valve 7 is determined to be in the abnormal open state and the alternative operation is performed.

  It is determined whether or not the elapsed time since activation of the water heater 1 in S401 is within a predetermined time (for example, 1 minute). If it is within the predetermined time, the process proceeds to S402, and if it exceeds the predetermined time, the process proceeds to S403. .

  If the elapsed time is within the predetermined time, it is determined whether or not the expansion valve 7 is in an open abnormal state in S402. If it is determined that the expansion valve 7 is in an open abnormal state, the process proceeds to S404 and a normal state that is not determined as an open abnormal state. In this case, the process proceeds to S405.

  When the expansion valve 7 is in a normal state, in S405, in order to stabilize the ejector cycle 2, the target opening that is fixed with the throttle opening of the expansion valve 7 and the passage opening of the nozzle portion 50 of the ejector 5 as the initial opening is fixed. Set to degrees.

  If the expansion valve 7 is in an abnormal open state, the passage opening of the nozzle portion 50 of the ejector 5 is set to a target opening fixed at an opening smaller than the initial opening in the normal state in S404. By reducing the passage opening degree of the nozzle portion 50 of the ejector 5, the high-pressure side pressure between the compressor 3 and the ejector 5 can be increased. Therefore, the shortage of heating capacity in the water refrigerant heat exchanger 4 can be compensated. In S406, the throttle opening degree of the expansion valve 7 is set again to the target opening degree that makes the fully closed state.

  If the elapsed time exceeds the predetermined time in the determination in S401, the temperature difference ΔT (ΔT = refrigerant outlet temperature Tro−) between the refrigerant outlet temperature detected by the refrigerant temperature sensor 31 and the feed water temperature detected by the feed water temperature sensor 35 in S403. A target temperature difference is calculated based on the feed water temperature Twi), the outside air temperature, and the boiling target temperature Tp. Further, the target pressure of the high-pressure side pressure is calculated from the calculated target temperature difference by a control map or feedback control stored in advance in the ROM.

  In S407, it is determined whether or not the expansion valve 7 is in an abnormal opening state. If the expansion valve 7 is in an abnormal opening state, the process proceeds to S409, and if it is normal, the process proceeds to S408.

  When the expansion valve 7 is in a normal state, the target opening is determined in S408 so that the throttle opening of the expansion valve 7 and the passage opening of the nozzle portion 50 of the ejector 5 become the target pressure. Thereby, by controlling the pressure on the high pressure side to the target pressure, the hot water can be heated to the target temperature in the water / refrigerant heat exchanger 4.

  When the expansion valve 7 is in an abnormal open state, the target opening degree of the passage opening degree of the nozzle portion 50 of the ejector 5 is determined in S409 so as to improve the responsiveness more than the normal state (S408). For example, when the target opening is calculated from the target pressure by a well-known PID control, the responsiveness is enhanced by increasing a proportional gain or the like that increases or decreases the target opening. Thereby, the time for hot water to reach the boiling target temperature Tp can be shortened.

  As described above, when the expansion valve 7 is in an abnormal open state, the pressure value on the high-pressure side can be increased by performing an alternative operation of the water heater 1 in the valve opening determination process and the compressor rotation speed determination process. It is possible to compensate for the lack of heating capacity of hot water in the water / refrigerant heat exchanger 4.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. In the present embodiment, only the parts different from the second embodiment will be described.

  In the present embodiment, as in the second embodiment, the hot water heater 1 is replaced when it is determined in the failure diagnosis process of the first embodiment that the throttle opening of the expansion valve 7 is in an abnormal open state that cannot be fully closed. The operation will be described.

  In the second embodiment, the alternative operation is executed in the valve opening determination process shown in S105 of FIG. 2, but in this embodiment, the alternative operation is executed in the compressor rotation speed determination process shown in S108 of FIG. Make up for the lack of heating capacity of the water heater 1.

  The compressor rotation speed determination process when performing the alternative operation will be described with reference to FIG. FIG. 7 shows a flowchart of the compressor rotational speed determination process when the expansion valve 7 is determined to be in the abnormal open state and the alternative operation is performed.

  In S501, it is determined whether or not the elapsed time after starting the water heater 1 is within a predetermined time (for example, 1 minute). If it is within the predetermined time, the process proceeds to S502, and if it exceeds the predetermined time, the process proceeds to S503. move on.

  If the elapsed time is within the predetermined time, it is determined in S502 whether or not the expansion valve 7 is in an abnormal opening state. If it is in an abnormal opening state, the process proceeds to S505, and if it is normal, the process proceeds to S504.

  If the expansion valve 7 is in a normal state, in step S504, in order to stabilize the ejector cycle 2, the rotation speed of the compressor 3 is set to a fixed target rotation speed as an initial setting.

  If the expansion valve 7 is in an abnormal open state, the rotational speed of the compressor 3 is set to a target rotational speed that is fixed at a rotational speed increased from the target rotational speed at the initial setting in the normal state (S504) in S505. . The high-pressure side pressure can be increased by increasing the rotation speed from the target rotation speed initially set in the normal state (S504). Therefore, it is possible to compensate for the lack of heating capacity of hot water in the water / refrigerant heat exchanger 4.

If the elapsed time exceeds the predetermined time in the determination in S501, in S503,
Based on the outside air temperature detected by the outside air temperature sensor 34, the target rotational speed of the compressor 3 is calculated. Next, in S506, it is determined whether or not the expansion valve 7 is in an abnormal open state. If it is abnormal, the process proceeds to S508, and if it is normal, the process proceeds to S507.

  If the expansion valve 7 is in a normal state, the target rotational speed of the compressor 3 calculated in S503 is set in S507.

  When the expansion valve 7 is in an abnormal opening state, in S508, the rotation speed obtained by increasing a predetermined rotation speed (for example, 500 rpm) to the target rotation speed of the compressor 3 calculated in S503 is set as the target rotation speed.

  Thereby, since the pressure on the high pressure side is increased by increasing the target rotational speed of the compressor 3, it is possible to compensate for the lack of heating capacity of the hot water in the water / refrigerant heat exchanger 4.

  As described above, when the expansion valve 7 is in an abnormal open state, the pressure value on the high-pressure side can be increased by performing an alternative operation of the water heater 1 in the compressor rotation speed determination process, and water refrigerant heat exchange is performed. Insufficient heating capacity of the hot water in the vessel 4 can be compensated.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described based on FIG. 3, FIG. 4, and FIG. In the third embodiment, only portions different from the first embodiment will be described. FIG. 8 shows a flowchart of the failure diagnosis process.

  In the first embodiment described above, in the abnormality determination process (FIG. 3), the failure diagnosis process in the open abnormal state where the throttle opening of the expansion valve 7 cannot be fully closed is executed. In the third embodiment, however, the ejector Failure diagnosis processing for a fully-closed abnormal state in which the passage opening degree of the nozzle unit 50 of 5 cannot be opened is executed. Here, the fully-closed abnormal state in which the passage opening degree of the nozzle portion 50 of the ejector 5 cannot be opened is that the throttle opening degree is fully closed from the control unit 100 to the actuator that controls the throttle opening degree of the expansion valve 7. In the case where an instruction to make the state is made and an instruction to make the passage opening degree of the nozzle portion 50 of the ejector 5 open, the passage opening degree of the nozzle portion 50 of the ejector 5 cannot be made open, that is, the fully closed state is set. I mean. In addition, when performing the failure diagnosis process of this embodiment, the passage opening degree of the nozzle part 50 of the ejector 5 shall be controlled by the open state.

  In the third embodiment, the processing contents of S304 to S306 shown in FIG. 4 are changed to the processing contents of S307 to S309 shown in FIG. Since the other processing contents are the same as those described in the first embodiment, the description thereof is omitted.

  First, if it is determined in S303 that the time measured by the failure diagnosis timer has not passed the predetermined time, the process proceeds to S307.

  In S307, it is determined whether or not the pressure detected by the pressure sensor 37 is equal to or higher than a predetermined pressure (for example, 16.5 MPa). Here, since the pressure sensor 37 is disposed on the downstream side of the water-refrigerant heat exchanger 4 and on the upstream side of the branch passage 22, it can detect the high-pressure side pressure.

  By making the throttle opening of the expansion valve 7 fully closed, the refrigerant that has flowed out of the water-refrigerant heat exchanger 4 flows only into the ejector 5 that is controlled to be in the open state. In this case, since the refrigerant flows out from the ejector 5, the high-pressure side pressure between the ejector 5 and the expansion valve 7 from the compressor 3 does not become an abnormally high pressure. Therefore, conversely, when the pressure detected by the pressure sensor 37 is an abnormally high pressure exceeding the predetermined pressure, it can be determined that the ejector 5 is in the fully closed abnormal state.

  If the pressure detected by the pressure sensor 37 is equal to or higher than the predetermined pressure in S307, the ejector 5 is determined to be in a fully closed abnormal state in S308, and the fully closed abnormal state is recorded in the RAM or the like of the control device 100. If the pressure detected by the pressure sensor 37 is smaller than the predetermined pressure in S307, it is determined in S309 that the passage opening of the nozzle portion 50 of the ejector 5 is in a normal state that can be opened, and the RAM of the control device 100 Record the normal state.

  As described above, when the throttle opening of the expansion valve 7 is fully closed and the passage opening of the nozzle portion 50 of the ejector 5 is opened, the pressure sensor 37 that detects the pressure on the high pressure side is equal to or higher than a predetermined pressure. Can be identified as the cause of the failure of the ejector 5 of the water heater 1 by determining that the ejector 5 is in the fully closed abnormal state.

(Fifth embodiment)
Next, a fifth embodiment of the present invention will be described based on FIG. 3, FIG. 4, and FIG. In the present embodiment, only the parts different from the first embodiment will be described. FIG. 9 shows a flowchart of the failure diagnosis process.

  In the first embodiment described above, in the abnormality determination process (FIG. 3), only the failure diagnosis process in the open abnormal state in which the throttle opening of the expansion valve 7 cannot be fully closed is executed. In the present embodiment, however, the expansion valve In addition to the failure diagnosis processing in the open abnormal state, the failure diagnosis processing in the fully closed abnormal state in which the passage opening degree of the nozzle portion 50 of the ejector 5 cannot be opened is executed. In addition, when performing the failure diagnosis process of this embodiment, the passage opening degree of the nozzle part 50 of the ejector 5 is controlled to be in an open state.

  In the present embodiment, the processing content of S306 shown in FIG. 4 is changed to the processing content of S310 to S312 shown in FIG. Since the other processing contents are the same as those described in the first embodiment, the description thereof is omitted.

  First, in S304, when the second evaporator refrigerant temperature difference is smaller than the predetermined temperature difference, the process proceeds to S310.

  In S310, it is determined whether or not the pressure detected by the pressure sensor 37 that detects the high-pressure side pressure is equal to or higher than a predetermined pressure (for example, 16.5 MPa). Since the throttle opening of the expansion valve 7 is fully closed in S302, the refrigerant that has flowed out of the water-refrigerant heat exchanger 4 flows only into the ejector 5. In this case, since the refrigerant flows out from the ejector 5, the high-pressure side pressure between the ejector 5 and the expansion valve 7 from the compressor 3 does not become an abnormally high pressure. Therefore, conversely, when the pressure detected by the pressure sensor is an abnormally high pressure exceeding a predetermined pressure, it can be determined that the ejector is in the fully closed abnormal state.

  If the pressure detected by the pressure sensor 37 is equal to or higher than the predetermined pressure in S310, the ejector 5 is determined to be in a fully closed abnormal state in S311 and the fully closed abnormal state is recorded in the RAM or the like of the control device 100.

  If the pressure detected by the pressure sensor 37 is smaller than the predetermined pressure in S310, the throttle opening of the expansion valve 7 can be fully closed in S312 and the passage of the nozzle portion 50 of the ejector 5 is opened. The normal state is determined to be an open state, and the normal state is recorded in the RAM or the like of the control device 100.

  As described above, when the throttle opening of the expansion valve 7 is fully closed and the passage opening of the nozzle portion 50 of the ejector 5 is opened, the second evaporator refrigerant temperature difference is outside the range of error or the like. If there is, it can be determined that the expansion valve 7 is in an abnormal open state. When the pressure sensor 37 that detects the pressure on the high-pressure side is in a high pressure state that is equal to or higher than a predetermined pressure, it can be determined that the ejector 5 is in a fully closed abnormal state, and therefore the expansion valve 5 of the water heater 1 and The cause of the failure of the ejector 5 can be identified.

(Sixth embodiment)
Next, a sixth embodiment of the present invention will be described with reference to FIG. In the present embodiment, the alternative operation in the case where it has been determined in the above-described second embodiment that the throttle opening of the expansion valve 7 is in an open abnormal state in which the expansion valve 7 cannot be fully closed has been described. An alternative operation when the ejector 5 shown in the embodiment and the fifth embodiment is determined to be in the fully closed abnormal state will be described.

  The purpose of the alternative operation in the present embodiment is to eliminate the abnormal high pressure between the compressor 1 and the ejector 5 and the expansion valve 7 of the water heater 1 that is caused by the fully closed abnormal state of the ejector 5. Here, the reason for the abnormally high pressure is that the passage opening degree of the nozzle portion 50 of the ejector 5 cannot be opened, and therefore, when the throttle opening degree of the expansion valve 7 is small, the high pressure side pressure exceeds a predetermined pressure value. It is.

  Therefore, in this embodiment, the abnormal high pressure of the water heater 1 is eliminated by executing an alternative operation in the valve opening determination process shown in S105 in FIG. In addition, since the water heater 1 has an abnormally high pressure, the heating capacity of the water heater 1 is sufficiently satisfied.

  The valve opening determination process in the case of performing an alternative operation will be described with reference to FIG. FIG. 10 shows a flowchart of the valve opening degree determination process when the ejector 5 is determined to be in the fully closed abnormal state and the alternative operation is performed.

  In S601, it is determined whether or not the elapsed time since the start of the water heater 1 is within a predetermined time (for example, 1 minute). If it is within the predetermined time, the process proceeds to S602, and if it exceeds the predetermined time, the process proceeds to S603. .

  If the elapsed time is within the predetermined time, it is determined in S602 whether or not the ejector 5 is in the fully closed abnormal state. If it is in the fully closed abnormal state, the process proceeds to S605, and if it is in the normal state, the process proceeds to S604.

  When the ejector 5 is in a normal state, in S604, in order to stabilize the ejector cycle 2, a fixed target opening is set with the throttle opening of the expansion valve 7 and the passage opening of the nozzle portion 50 of the ejector 5 as initial settings. Set.

  If the ejector 5 is in the fully closed abnormal state, in S605, the throttle opening degree of the expansion valve 7 is set to a target opening degree that is larger than the target opening degree in the normal state. By increasing the throttle opening of the expansion valve 7, the high pressure side pressure between the compressor 3 and the ejector 5 can be eliminated. In S606, the target opening is set so that the passage opening of the nozzle portion 50 of the ejector 5 is opened.

  If the elapsed time exceeds the predetermined time, in S603, the temperature difference ΔT between the refrigerant outlet temperature detected by the refrigerant temperature sensor 31 and the feed water temperature detected by the feed water temperature sensor 35 (ΔT = refrigerant outlet temperature Tro−feed water temperature Twi). The target temperature difference is calculated based on the outside air temperature and the boiling target temperature Tp. Further, the target pressure of the high-pressure side pressure is calculated from the calculated target temperature difference by a control map or feedback control stored in advance in the ROM.

  In S607, it is determined whether or not the ejector 5 is in the fully closed abnormal state. If the ejector 5 is in the fully closed abnormal state, the process proceeds to S609. If the ejector 5 is in the normal state, the process proceeds to S608.

  If the ejector 5 is in a normal state, the target opening is set so that the throttle opening of the expansion valve 7 and the passage opening of the nozzle portion 50 of the ejector 5 become the target pressure in S608.

  Thereby, the hot water supply water can be heated in the water refrigerant heat exchanger 4.

  When the ejector 5 is in the fully closed abnormal state, the target opening degree of the throttle opening of the expansion valve 7 is determined so that the throttle opening degree of the expansion valve 7 is lower than the normal state in S609. For example, when the target opening is calculated from the target pressure by a well-known PID control, the responsiveness is lowered by reducing a proportional gain or the like that increases or decreases the target opening.

  Thereby, by reducing the change amount of the passage opening degree of the nozzle portion 50 of the ejector 5, it is possible to eliminate the abnormal high pressure while the heating capacity of the water heater 1 is stable.

  As described above, when the ejector 5 is in the fully closed abnormal state, the abnormal high pressure on the high pressure side in the ejector cycle 2 can be eliminated by performing an alternative operation of the water heater 1 in the valve opening determination process. Moreover, the heating capability of the water heater 1 can be stabilized.

(Seventh embodiment)
Next, a seventh embodiment of the present invention will be described based on FIG. 3, FIG. 4, and FIG. In the present embodiment, only the parts different from the first embodiment will be described. FIG. 11 shows a flowchart of the failure diagnosis process.

  In the first embodiment described above, in the abnormality determination process (FIG. 3), the failure diagnosis process in the open abnormal state where the throttle opening of the expansion valve 7 cannot be fully closed is executed. However, in this embodiment, the expansion valve 7 A failure diagnosis process for a fully closed abnormal state in which the throttle opening of the valve cannot be opened is executed. Here, the fully closed abnormal state in which the expansion valve 7 cannot be opened means that the throttle opening of the expansion valve 7 is opened when the ejector 5 is instructed to fully close by the control device 100. It means that you can't. In addition, when performing the failure diagnosis process of this embodiment, the throttle opening degree of the expansion valve 7 is controlled to an open state.

  In the present embodiment, the processing contents of S302 and S304 to S306 shown in FIG. 4 are changed to the processing contents of S313 and S314 to S316 shown in FIG. Since the other processing contents are the same as those described in the first embodiment, the description thereof is omitted.

  First, in S301, when it is determined that the failure diagnosis mode has not been started, the process proceeds to S313, and a target opening that sets the passage opening of the nozzle portion 50 of the ejector 5 to a fully closed state is set. At the same time, the failure diagnosis timer is operated to measure the time that has elapsed since the target opening that sets the passage opening of the nozzle portion 50 of the ejector 5 to the fully closed state is set.

  If it is determined in S303 that the time measured by the failure diagnosis timer has passed the predetermined time, the process proceeds to S314.

  In S314, it is determined whether or not the pressure detected by the pressure sensor 37 is equal to or higher than a predetermined pressure (for example, 16.5 MPa).

  By setting the passage opening degree of the nozzle portion 50 of the ejector 5 to the fully closed state, the refrigerant flowing out of the water-refrigerant heat exchanger 4 flows only into the expansion valve 7. In this case, since the refrigerant flows out from the expansion valve 7, the high-pressure side pressure between the ejector 5 and the expansion valve 7 from the compressor 3 does not become an abnormally high pressure. Therefore, if the pressure detected by the pressure sensor 37 is an abnormally high pressure exceeding the predetermined pressure, it can be determined that the expansion valve 7 is in a fully closed abnormal state.

  If the pressure detected by the pressure sensor 37 is greater than or equal to the predetermined pressure in S314, it is determined in S315 that the expansion valve 7 is in a fully closed abnormal state, and the fully closed abnormal state is recorded in the RAM or the like of the control device 100. If the pressure detected by the pressure sensor 37 is smaller than the predetermined pressure in S314, it is determined in S316 that the throttle opening of the expansion valve 7 is in the open state, and is normal in the RAM of the control device 100. Record state.

  As described above, when the passage opening of the nozzle portion 50 of the ejector 5 is fully closed and the throttle opening of the expansion valve is opened, the pressure sensor 37 for detecting the pressure on the high pressure side is equal to or higher than a predetermined pressure. When it is in a high pressure state, it can be identified as the cause of the failure of the ejector 5 of the water heater 1 by determining that the expansion valve 7 is in a fully closed abnormal state.

(Other embodiments)
In each of the above-described embodiments, the throttle opening of the expansion valve 7 or the passage opening of the nozzle portion 50 of the ejector 5 is fully closed based on the result of the abnormality determination process. For example, the failure diagnosis process may be performed by fully closing the throttle opening of the expansion valve 7 or the passage opening of the nozzle portion 50 of the ejector 5 by executing the mode.

  Moreover, although each said embodiment applies the failure diagnosis process of the ejector cycle 2 of this invention to the water heater 1, you may apply to a vehicle air conditioner etc. When used in a vehicle air conditioner, the water-refrigerant heat exchanger 4 is used as a condenser that condenses the refrigerant, and the first evaporator 6 and the second evaporator 7 are each cooled with air supplied to the vehicle interior. It can be applied by using it as an evaporator.

  In the second embodiment and the third embodiment, an alternative operation is executed in the valve opening determination process shown in S105 of FIG. 2 in the second embodiment, and in the third embodiment, the compressor rotation shown in S108 of FIG. Although the alternative operation is executed individually in the number determination process, not limited to this, the alternative operation performed in the valve opening determination process and the compressor rotation speed determination process is executed simultaneously to compensate for the lack of heating capacity of the water heater 1. May be.

It is a conceptual diagram which shows the whole structure of the water heater of the said 1st Embodiment. It is a flowchart which shows the outline of the whole control of the water heater of the said 1st Embodiment. It is a flowchart which shows the abnormality determination process of the said 1st Embodiment. It is a flowchart which shows the failure diagnosis process of the said 1st Embodiment. It is a control characteristic figure showing the relation between elapsed time and the 2nd evaporator temperature difference. It is a flowchart which shows the valve opening degree determination process in the case of performing the alternative driving | operation of the said 2nd Embodiment. It is a flowchart which shows the compressor speed determination process in the case of performing the alternative driving | operation of the said 3rd Embodiment. It is a flowchart which shows the failure diagnosis process of the said 4th Embodiment. It is a flowchart which shows the failure diagnosis process of the said 5th Embodiment. It is a flowchart which shows the valve opening determination process in the case of performing the alternative driving | operation of the said 6th Embodiment. It is a flowchart which shows the failure diagnosis process of the said 7th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Hot water heater, 2 ... Ejector cycle, 3 ... Compressor, 4 ... Radiator, 5 ... Ejector, 7 ... Expansion valve, 8 ... 2nd evaporator, 22 ... Branch passage, 32 ... 1st temperature detection means, 33 ... 2nd temperature detection means, 37 ... Pressure detection means, 100 ... Control apparatus.

Claims (6)

A compressor (3) for sucking and compressing refrigerant;
A radiator (4) that radiates heat of the high-pressure refrigerant discharged from the compressor (3);
A nozzle part (50) for decompressing and expanding the refrigerant on the downstream side of the radiator (4), and a gas-phase refrigerant suction in which the gas-phase refrigerant is sucked by a high-speed refrigerant flow injected from the nozzle part (50). An ejector (5) having a mouth (51) and a booster (53) for converting the velocity energy of the refrigerant flow obtained by mixing the high-speed refrigerant flow and the gas-phase refrigerant into pressure energy;
A first evaporator (6) that evaporates the refrigerant flowing out of the ejector (5) and whose refrigerant outflow side is connected to the suction side of the compressor (3);
A branch passage (22) for branching a refrigerant flow between the radiator (4) and the ejector (5) and guiding the refrigerant flow to the gas-phase refrigerant suction port (51);
Throttle means (7) disposed in the branch passage (22) and capable of reducing the refrigerant in the branch passage (22) and closing the branch passage (22) by fully closing the throttle opening. When,
A second evaporator (8) disposed downstream of the throttle means (7) in the branch passage (22) and evaporating the refrigerant decompressed by the throttle means (7);
Throttle opening control means for controlling the throttle opening of the throttle means (7);
First temperature detection means (32) for detecting a refrigerant temperature downstream of the throttle means (7) and upstream of the second evaporator (8);
Second temperature detection means (33) for detecting a refrigerant temperature downstream of the second evaporator (8) and upstream of the refrigerant suction port (51);
The refrigerant temperature and the second temperature detected by the first temperature detecting means (32) when the throttle opening degree of the throttle means (7) is controlled to be fully closed by the throttle opening degree control means. An abnormality determination unit that determines that the throttle unit (7) is in an open abnormal state where the throttle opening cannot be fully closed when the difference between the refrigerant temperature detected by the detection unit (33) is greater than a predetermined value; ,
An ejector cycle comprising: An ejector opening degree control means for increasing the passage opening degree of the nozzle portion (50) of the ejector (5) more than that at the time of determination when the abnormality determining means determines that the opening is abnormal;
Alternatively, it comprises at least one of a rotational speed control means for increasing the rotational speed of the compressor (3) when it is determined to be in the open abnormal state by the abnormality determining means. The ejector cycle according to 1. Ejector opening degree control means for controlling the passage opening degree of the nozzle part (50);
Pressure detection means (37) for detecting the pressure of the refrigerant downstream of the compressor (3) and upstream of the ejector (5);
The throttle opening control means controls the throttle opening of the throttle means (7) to be fully closed, and the ejector opening control means opens the passage opening of the nozzle section (50). When the control is performed, the abnormality determination unit does not determine that the abnormality is in the open state, and if the pressure detected by the pressure detection unit is greater than a predetermined value, the ejector (5) The ejector cycle according to claim 1, wherein the passage opening degree of the nozzle portion (50) is determined to be a fully closed abnormal state in which the nozzle portion (50) cannot be opened. A compressor (3) for sucking and compressing refrigerant;
A radiator (4) for radiating heat of the high-pressure refrigerant discharged from the compressor;
A nozzle part (50) for decompressing and expanding the refrigerant on the downstream side of the radiator (4), and a gas-phase refrigerant suction in which the gas-phase refrigerant is sucked by a high-speed refrigerant flow injected from the nozzle part (50). An ejector (5) having a mouth (51) and a booster (53) for converting the velocity energy of the refrigerant flow obtained by mixing the high-speed refrigerant flow and the gas-phase refrigerant into pressure energy;
A first evaporator (6) that evaporates the refrigerant flowing out of the ejector (5) and whose refrigerant outflow side is connected to the suction side of the compressor (3);
A branch passage (22) for branching a refrigerant flow between the radiator (4) and the ejector (5) and guiding the refrigerant flow to the gas-phase refrigerant suction port (51);
Throttle means (7) disposed in the branch passage (22) and capable of reducing the refrigerant in the branch passage (22) and closing the branch passage (22) by fully closing the throttle opening. When,
A second evaporator (8) disposed downstream of the throttle means (7) in the branch passage (22) and evaporating the refrigerant decompressed by the throttle means (7);
Throttle opening control means for controlling the throttle opening of the throttle means (7);
Ejector opening degree control means for controlling the passage opening degree of the nozzle part (50);
Pressure detection means (37) for detecting the pressure of the refrigerant downstream of the compressor (3) and upstream of the ejector (5);
The throttle opening control means controls the throttle opening of the throttle means (7) to be fully closed, and the ejector opening control means opens the passage opening of the nozzle section (50). If the pressure detected by the pressure detection means is greater than a predetermined value, the ejector (5) cannot fully open the passage opening of the nozzle part (50). An abnormality determining means for determining an abnormal state;
An ejector cycle comprising: The throttle opening control means increases the opening of the throttle means (7) more than at the time of determination when the abnormality determination means determines that the fully closed abnormal state is present. Ejector cycle described in. A compressor (3) for sucking and compressing refrigerant;
A radiator (4) for radiating heat of the high-pressure refrigerant discharged from the compressor;
A nozzle part (50) for decompressing and expanding the refrigerant on the downstream side of the radiator (4), and a gas-phase refrigerant suction in which the gas-phase refrigerant is sucked by a high-speed refrigerant flow injected from the nozzle part (50). An ejector (5) having a mouth (51) and a booster (53) for converting the velocity energy of the refrigerant flow obtained by mixing the high-speed refrigerant flow and the gas-phase refrigerant into pressure energy;
A first evaporator (6) that evaporates the refrigerant flowing out of the ejector (5) and whose refrigerant outflow side is connected to the suction side of the compressor (3);
A branch passage (22) for branching a refrigerant flow between the radiator (4) and the ejector (5) and guiding the refrigerant flow to the gas-phase refrigerant suction port (51);
Throttle means (7) disposed in the branch passage (22) and capable of reducing the refrigerant in the branch passage (22) and closing the branch passage (22) by fully closing the throttle opening. When,
A second evaporator (8) disposed downstream of the throttle means (7) in the branch passage (22) and evaporating the refrigerant decompressed by the throttle means (7);
Throttle opening control means for controlling the throttle opening of the throttle means (7);
An ejector opening degree control means for controlling the passage opening degree of the nozzle part (50) and controlling the refrigerant passage of the nozzle part (50) to be fully closed;
Pressure detection means (37) for detecting the pressure of the refrigerant downstream of the compressor (3) and upstream of the ejector (5);
The ejector opening control means controls the passage opening of the nozzle section (50) to be fully closed, and the throttle opening control means opens the throttle opening of the throttle means (7). If the pressure detected by the pressure detection means (37) is greater than a predetermined value, the throttle means (7) is in a fully closed abnormal state where the throttle opening cannot be opened. An abnormality determining means for determining;
An ejector cycle comprising:

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