JP4063276B2 - Heat pump type water heater - Google Patents

Description

  The present invention relates to a heat pump type hot water supply apparatus that circulates a refrigerant in a heat pump cycle to heat hot water supply water to make hot water.

As a conventional heat pump type hot water supply apparatus, for example, one disclosed in Patent Document 1 is known. This hot water supply apparatus includes a refrigerant circuit (heat pump cycle) in which a compressor, a water refrigerant heat exchanger (radiator), a decompressor and an air heat exchanger (evaporator) are sequentially connected by refrigerant piping, a hot water tank, a circulation pump, A hot water supply circuit in which the water refrigerant heat exchanger is sequentially connected by a hot water pipe is provided so that hot water is heated (converted into hot water) by a high temperature refrigerant in the water refrigerant heat exchanger. Here, the refrigerant pressure on the high pressure side when the heat pump cycle is operated is set to be equal to or higher than the critical pressure (supercritical heat pump cycle), and flows into the water refrigerant heat exchanger and the refrigerant flowing out of the water refrigerant heat exchanger. For example, the refrigerant pressure on the high pressure side is controlled such that the temperature difference ΔT with the hot water supply water becomes a predetermined temperature difference ΔT ₀ .

As a result, the high-pressure side refrigerant does not change phase in the supercritical region, and can change temperature substantially linearly in heat exchange with hot water supply water, and the temperature difference ΔT can be reduced to reduce the temperature difference in the water refrigerant heat exchanger. The heat exchange efficiency (the amount of heat transferred to hot water supply water Q / ΔT) is improved.
Japanese Patent No. 3227651

  However, the hot water supply device described in Patent Document 1 shows efficient operation control at the time of steady operation of the heat pump cycle, and does not consider operation control at the time of heat pump cycle activation.

  That is, after the operation of the heat pump cycle is started, when the time to reach a stable operation becomes long, heat exchange between the high-pressure refrigerant that has not reached the target temperature and the hot water supply water is performed, The amount of hot water that does not reach the target hot water temperature will increase. This is the amount of hot water that cannot be used for hot water supply.

  Moreover, the amount of hot water cannot be ensured although it can be brought close to the target hot water temperature by lowering the circulation amount of hot water supply water and exchanging heat for the lower temperature of the high-pressure side refrigerant. On the other hand, if the temperature and pressure of the high-pressure side refrigerant are increased at a stretch in a short time, hunting may occur or, in the worst case, the compressor or the like may be damaged.

  In view of the above problems, an object of the present invention is to provide a heat pump hot water supply apparatus that can reach the target heating capacity in a short time after startup.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the present invention, the compressor (21), the water-refrigerant heat exchanger (22), the decompressor (23), and the air heat exchanger (24) are sequentially connected, and the heat pump in which the refrigerant flows inside. Water for hot water supply flows through the cycle (2), the control means (3) for controlling the operation of the compressor (21), the valve opening (Z) of the decompressor (23), and the water-refrigerant heat exchanger (22). In the heat pump type hot water supply apparatus provided with a hot water supply circuit (17), and hot water supply water is heated by the refrigerant in the water refrigerant heat exchanger (22), the control means (3) starts the compressor (21). When the characteristic value (PH) related to the heating capacity of the refrigerant with respect to the hot water supply water is controlled to the target value (PHm), the throttle amount (ΔZ) of the decompressor (23) to be throttled from the present time to a predetermined time later is set as the target. Value (PHm) and the current characteristic value (PHn) The larger the absolute value of (PHm−PHn), and the smaller the absolute value of the change rate (ΔPHn−ΔPHb) from a predetermined time before this difference (PHm−PHn) to the present time, the larger the value is determined. The difference (Zn / Zm) between the current valve opening (Zn) at the current time and the target valve opening (Zm) of the pressure reducer (23) corresponding to the target value (PHm) is large. The correction is made as a corrected throttle amount (ΔZh) so as to increase, and the current valve opening (Zn) is varied using this corrected throttle amount (ΔZh).

  Thereby, immediately after the compressor (21) is started, the throttle amount (ΔZ) is set to be large, and as the characteristic value (PH) approaches the target value (PHm), the throttle amount ΔZ is set to be small. Without causing it, the characteristic value (PH) of the refrigerant can reach the target value (PHm) in a short time. That is, the heating capacity of the refrigerant can be ensured in a short time.

  The larger the difference (Zn / Zm) from the current valve opening (Zm) with respect to the target valve opening (Zm), the larger the throttle amount (ΔZ) is set as the corrected throttle amount (ΔZh). The time until the characteristic value (PH) reaches the target value (PHm) can be further shortened.

  As the characteristic value (PH) in the invention described in claim 1, the high pressure side pressure (PH) can be used as in the invention described in claim 2. Further, as in the invention described in claim 3, the high pressure side temperature may be used as the characteristic value.

  In the invention according to claim 4, the heat pump in which the compressor (21), the water refrigerant heat exchanger (22), the pressure reducer (23), and the air heat exchanger (24) are sequentially connected, and the refrigerant flows therethrough. Water for hot water supply flows through the cycle (2), the control means (3) for controlling the operation of the compressor (21), the valve opening (Z) of the decompressor (23), and the water-refrigerant heat exchanger (22). In the heat pump type hot water supply apparatus provided with a hot water supply circuit (17), and hot water supply water is heated by the refrigerant in the water refrigerant heat exchanger (22), the control means (3) starts the compressor (21). When the pressure (P) or the temperature related to the heating capacity of the refrigerant with respect to the hot water supply water is controlled to the target value (PHm), the throttle amount (ΔZ) of the decompressor (23) to be throttled from the present time to a predetermined time later, High pressure side characteristic value (PHn) and low pressure side characteristic of refrigerant The difference between the height difference (PHn−PLn) with respect to (PLn) becomes smaller, and the smaller the rate of change (ΔPn−ΔPb) from a predetermined time before this height difference (PHn−PLn) to the present time, the larger the difference. The throttle amount (ΔZ) determined is determined as a difference between the current valve opening (Zn) at the current time and the target valve opening (Zm) of the pressure reducer (23) corresponding to the target value (PHm) (Zn / It is characterized by correcting as the corrected throttle amount (ΔZh) so as to increase as Zm) increases, and varying the current valve opening (Zn) using this corrected throttle amount (ΔZh).

  Thus, similarly to the first aspect of the invention, immediately after the compressor (21) is started, the throttle amount (ΔZ) is set to be large, and as the characteristic value (PH) approaches the target value (PHm), Since the amount ΔZ is set small, the characteristic value (PH) of the refrigerant can reach the target value (PHm) in a short time without causing hunting. The time until the refrigerant characteristic value (PH) reaches the target value (PHm) can be further shortened by the corrected throttle amount (ΔZh).

  In the invention described in claim 4, as in the invention described in claim 5, the high pressure side pressure (PHn) as the high pressure side characteristic value (PHn) and the low pressure side pressure (PLn) as the low pressure side characteristic value (PLn). ) Can be used. Further, as in the invention described in claim 6, the high pressure side temperature may be used as the high pressure side characteristic value, and the low pressure side temperature may be used as the low pressure side characteristic value.

  In the invention described in claim 5, as in the invention described in claim 7, in detecting the low-pressure side pressure (PLn), the inlet side temperature of the refrigerant air heat exchanger (24), the compressor (21 ), And at least one of the ejector outlet temperature when the nozzle portion (27a) of the ejector (27) is used as the pressure reducer (23).

  The invention according to claim 8 is characterized in that the control means (3) regulates the predetermined correction aperture amount (ΔZhmax) as an upper limit value when correcting the aperture amount (ΔZ).

  Thereby, the rapid increase of the characteristic value (PH) on the high pressure side of the refrigerant is suppressed, and damage to the compressor (21) itself and various devices (22, 23) on the high pressure side in the heat pump cycle (2) is prevented. be able to.

  In invention of Claim 9, the nozzle part (27a) which decompresses and expands the high pressure refrigerant | coolant which flowed out from the water refrigerant | coolant heat exchanger (22), the refrigerant | coolant injected from a nozzle part (27a), and an air heat exchanger (24) And a pressure increasing part (27b) for increasing the pressure of the refrigerant by mixing with the gas-phase refrigerant sucked from), and the pressure reducer (23) is composed of a nozzle part (27a). It is a feature.

  Usually, in the ejector cycle in which the ejector (27) is used in the heat pump cycle (2), the refrigerant flows through the main circuit connecting the compressor (21), the water refrigerant heat exchanger (22), and the ejector (27). The refrigerant also has a cycle in which the refrigerant flows to the air heat exchanger (24). Therefore, when the characteristic value (PH) of the refrigerant reaches the target value (PHm) in a short time, the refrigerant flow rate to both the main circuit and the air heat exchanger (24) can be secured quickly, and the heating capacity is increased. The ejector cycle can be secured.

  The invention according to claim 10 is characterized in that the compressor (21) compresses and discharges the refrigerant in the heat pump cycle (2) to a critical pressure or higher.

  As a result, the refrigerant temperature in the heat pump cycle (2) can be increased, and the temperature difference from the hot water supply water can be increased to efficiently boil hot water.

  Further, as in the invention described in claim 11, the refrigerant in the heat pump cycle (2) can be specifically carbon dioxide.

  In addition, the code | symbol in the parenthesis attached | subjected to each said means shows an example of a corresponding relationship 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. 1 is a schematic diagram showing a schematic configuration of the heat pump type hot water supply apparatus 100, FIG. 2 is a flowchart used for starting control performed by the control apparatus 3, and FIG. 3 is a time chart showing the high pressure side pressure PH and the valve opening Z. FIG. 4 is a map for calculating the aperture amount ΔZ at the start control.

  1 is a hot water storage tank made of metal (for example, made of stainless steel) having excellent corrosion resistance, and a heat insulating material (not shown) is arranged on the outer periphery so that hot water for hot water supply can be kept warm for a long time. It has become. An introduction port 11 is provided in the lower part of the hot water storage tank 1, and an introduction pipe 12 for introducing tap water (corresponding to hot water supply water in the present invention, hereinafter referred to as water) into the hot water storage tank 1 in the introduction port 11. Is connected.

  On the other hand, a lead-out port 13 is provided in the upper part of the hot water storage tank 1, and a lead-out pipe 14 for leading out hot water in the hot water storage tank 1 is connected to the lead-out port 13. The outlet pipe 14 is provided with a mixing valve (not shown) at a junction with a water supply pipe (not shown). This mixing valve is connected to the opening area ratio (opening side of the hot water communicating with the outlet pipe 14 and the water supply pipe). By adjusting the ratio of the opening degree on the water side), hot water and water are appropriately mixed and supplied to the currant, shower, bath, etc. on the downstream side.

  A discharge port 15 for discharging water in the hot water storage tank 1 is provided at the lower part of the hot water storage tank 1, and an intake port 16 for sucking hot water into the hot water storage tank 1 is provided at the upper part of the hot water storage tank 1. Yes. The discharge port 15 and the suction port 16 are connected by a circulation circuit (corresponding to the hot water supply circuit in the present invention) 17, and a part of the circulation circuit 17 is a water / refrigerant heat exchanger 22 of a heat pump device (heat pump cycle) 2 described later. It is arranged in the inside.

  On the upstream side of the water refrigerant heat exchanger 22 in the circulation circuit 17, a circulation pump 18 for circulating (circulating) the water in the lower part of the hot water storage tank 1 toward the upper part in the circulation circuit 17 is disposed. . The position of the circulation pump 18 is not limited to the upstream side of the water / refrigerant heat exchanger 22 in the circulation circuit 17 and may be on the downstream side.

  On the other hand, a temperature sensor 19 for detecting the temperature of hot water flowing through the circulation circuit 17 (hot water heated by the water-refrigerant heat exchanger 22) is disposed downstream of the water-refrigerant heat exchanger 22 in the circulation circuit 17. Yes. The temperature sensor 19 outputs temperature information of hot water returning to the hot water storage tank 1 to the control device 3 described later.

Reference numeral 2 denotes a heat pump device. The heat pump device 2 has a compressor 21, a water refrigerant heat exchanger 22, an expansion valve (corresponding to the decompressor in the present invention) 23, an air heat exchanger 24, and an accumulator 25 connected in order. Carbon dioxide (CO ₂ ) is used as a refrigerant flowing inside.

  The compressor 21 is driven by a built-in electric motor (not shown), and compresses and discharges the gas-phase refrigerant sucked from the accumulator 25 to a critical pressure or higher. The drive source of the compressor 21 is not limited to the electric motor, and may be a power source such as an engine.

The water-refrigerant heat exchanger 22 exchanges heat between the high-temperature refrigerant (hot gas) discharged from the compressor 21 and the water supplied from the hot water storage tank 1 by the circulation pump 18. And a water passage (not shown) through which water flows, and the flow direction of the refrigerant flowing through the refrigerant passage and the flow direction of the water flowing through the water passage are opposed to each other. In addition, since the refrigerant (CO ₂ ) flowing through the water refrigerant heat exchanger 22 is pressurized to a critical pressure or higher by the compressor 21, the temperature of the refrigerant is reduced by dissipating heat to the water flowing through the water refrigerant heat exchanger 22. There is no condensation.

  The expansion valve 23 is a decompression device that decompresses refrigerant flowing out of the hot water supply heat exchanger 22 in an enthalpy-like manner according to the valve opening Z. Specifically, the expansion valve 23 adds a throttle amount ΔZ to the valve opening Z. By reducing the value, a larger pressure reduction is performed. In other words, by reducing the valve opening Z, the pressure is increased with respect to the high pressure side of the refrigerant. The opening degree Z of the expansion valve 23 is electrically controlled (by a stepping motor (not shown)) by the control device 3 described later.

  The air heat exchanger 24 evaporates the refrigerant decompressed by the expansion valve 23 by heat exchange with the outside air blown by the fan 24a. The accumulator 25 gas-liquid separates the refrigerant flowing out from the air heat exchanger 24 and causes the compressor 21 to suck only the gas-phase refrigerant and stores excess refrigerant in the cycle.

  And between the compressor 21 and the water refrigerant | coolant heat exchanger 22, the pressure sensor 26 as a pressure detection means is provided, and it concerns on the high voltage | pressure side pressure (the heating capability in this invention) of the refrigerant | coolant in the heat pump apparatus 2. FIG. (Corresponding to characteristic value) PH is detected. The pressure signal detected by the pressure sensor 26 is output to the control device 3 described later.

  The control device 3 that is a control means controls energization of the compressor 21 (substantially an electric motor that is a drive source), the expansion valve 23, the fan 24a, and the circulation pump 18, and the operation state of the compressor 21 and the expansion valve. 23 valve opening degree Z etc. are monitored. The control device 3 controls the compressor 21, the expansion valve 23, etc., absorbs heat from the outside air by the air heat exchanger 24, and heats the water flowing through the circulation circuit 17 by the water / refrigerant heat exchanger 22. Yes. Further, the control device 3 outputs a control signal based on temperature information from the temperature sensor 19 so that the temperature of the hot water that is heated by the water-refrigerant heat exchanger 22 and returns to the hot water storage tank 1 becomes the target boiling temperature. Then, the operation of the circulation pump 18 is controlled.

  Next, based on the said structure, the operation | movement which the heat pump type hot water supply apparatus 100 of this embodiment boils the hot water in the hot water storage tank 1 is demonstrated.

  When the power is supplied to the heat pump hot water supply device 100, the control device 3 is based on a signal from a switch or the like of an operation panel (not shown), setting conditions (for example, target boiling temperature, time condition), outside air temperature, and the like. In the middle of the night when the electricity rate is low, normal boiling operation control is executed. That is, the control device 3 operates the circulation pump 18 to circulate water in the circulation circuit 17 and also activates the heat pump device 2 to heat water flowing in the circulation circuit 17 in the water / refrigerant heat exchanger 22. To do. At this time, the temperature detected by the temperature sensor 19 is compared with the set target boiling temperature, and an operation instruction is given to the circulation pump 18 so that they match.

  In the present invention, the stage before the normal boiling operation, that is, the circulation pump 18 and the heat pump device 2 are operated (the valve opening Z of the expansion valve 23 is set to a predetermined opening on the fully open side according to the outside air temperature). Start-up control (especially the expansion valve 23) until the high-pressure side pressure PH obtained by the pressure sensor 26 reaches the target high-pressure side pressure (corresponding to the target value in the present invention) PHm. The control content is described below with reference to FIGS. 2 to 4.

  First, the control device 3 calculates the target high pressure side pressure PHm in step S100. That is, in order to set the temperature of the water heated by the water / refrigerant heat exchanger 22 from the outdoor temperature at that time and the temperature of the water obtained from the temperature sensor 19 to the target boiling temperature, the high-pressure side temperature of the refrigerant (water refrigerant) It is calculated how many times the inflow temperature to the heat exchanger 22) should be set, and the refrigerant pressure corresponding to this high pressure side temperature is set as the target high pressure side pressure PHm.

  Next, in step S110, the current high pressure side pressure PHn obtained from the pressure sensor 26 is read, and in step S120, it is determined whether or not the current high pressure side pressure PHn has reached the target high pressure side pressure PHm.

  If it is determined NO in step S120, the throttle amount ΔZ of the expansion valve 23 is calculated in step S130. Here, the throttle amount ΔZ is an amount indicating how much the valve opening Z is throttled by a predetermined time (after unit time) from the present time. The target high pressure side pressure PHm and the current high pressure side pressure It is determined according to the difference PHm−PHn (handled as an absolute value) from PHn and the rate of change ΔPHn−ΔPHb (handled as an absolute value) of the difference PHm−PHn from a predetermined time before (unit time before) to the present time. I have to. Here, the predetermined time is a time required for the refrigerant to circulate through the heat pump device 2 for one cycle (for example, 20 seconds).

  The change rate ΔPHn−ΔPHb will be further described in detail with reference to FIG. Assuming that the current high pressure side pressure is PHn and the high pressure side pressure before a predetermined time is PHb, the difference between the target high pressure side pressure PHm and the high pressure side pressure (PHn, PHb) at the present time and the predetermined time is PHm. −PHn (= ΔPHn) and PHm−PHb (= ΔPHb). The rate of change of the difference per predetermined time (from a predetermined time before to the current time) is obtained as (PHm−PHn) − (PHm−PHb) = ΔPHn−ΔPHb. In this case, since the high-pressure side pressure PH changes to the increasing side, ΔPHn <ΔPHb and the change rate ΔPHn−ΔPHb becomes a negative value, but hereinafter, the change rate ΔPHn−ΔPHb is an absolute value thereof. handle.

  Then, the aperture amount ΔZ is calculated (selected) based on the aperture amount calculation map shown in FIG. Here, the aperture amount calculation map is such that the aperture amount ΔZ is related to the difference PHm−PHn and the change rate ΔPHn−ΔPHb, and the aperture amount ΔZ changes as the difference PHm−PH increases. The smaller the rate ΔPHn−ΔPHb is, the larger it is.

  Next, the current valve opening degree (current valve opening degree) Zn in the expansion valve 23 is read in step S140, and the target valve opening degree Zm is calculated in step S150. The target valve opening Zm indicates an opening for setting the high pressure side pressure PH to the target high pressure side pressure PHm, and is calculated from the outside air temperature, the water temperature, and the target boiling temperature.

  Next, in step S160, the aperture amount ΔZ is corrected to calculate a corrected aperture amount ΔZh. That is, the corrected throttle amount ΔZh is corrected so that the throttle amount ΔZ increases as the difference between the current valve opening degree Zn and the target valve opening degree Zm increases. More specifically, FIG. ), The difference between the current valve opening degree Zn and the target valve opening degree Zm is defined as Zn / Zm, and the corrected throttle amount ΔZh is calculated by the following mathematical formula 1.

(Equation 1)
Correction aperture amount ΔZh = Aperture amount ΔZ × (Zn / Zm) × K
However, K is a predetermined constant.

  In step S170, the valve opening Z of the expansion valve 23 is varied (throttle) by the correction throttle amount ΔZh, and the process returns to step S100 and the above control is repeated. If it is determined in step S120 that the high pressure side pressure PH has reached the target high pressure side pressure PHm, the start control is stopped.

  Thus, immediately after the compressor 21 is started, the throttle amount ΔZ is set to be large, and as the high pressure side pressure PH approaches the target high pressure side pressure PHm, the throttle amount ΔZ is set to be small. Can reach the target high pressure side pressure PHm in a short time. That is, the heating capacity of the refrigerant can be ensured in a short time.

  The larger the difference Zn / Zm between the target valve opening degree Zm and the current valve opening degree Zn is, the larger the throttle amount ΔZ is set as the corrected throttle amount ΔZh. Therefore, the high pressure side pressure PH of the refrigerant is the target high pressure side pressure PHm. It is possible to further shorten the time required to reach.

  Further, in the present embodiment, carbon dioxide is used as a refrigerant so that the high-pressure side pressure PH is equal to or higher than the critical pressure. Therefore, the refrigerant temperature in the heat pump device 2 can be increased, and the temperature difference with water is increased. Thus, it is possible to efficiently boil hot water.

  In the present embodiment, the high pressure side pressure PH is detected by the pressure sensor 26 provided between the compressor 21 and the water refrigerant heat exchanger 22, but not limited thereto, the water refrigerant heat exchanger 22 You may make it detect between the expansion valves 23. FIG.

  Moreover, although the high pressure side pressure PH was used as the characteristic value related to the heating capacity of the refrigerant with respect to water, instead of this, the high pressure side temperature of the refrigerant (the temperature between the compressor 21 and the water refrigerant heat exchanger 22, or Or the temperature between the water-refrigerant heat exchanger 22 and the expansion valve 23).

(Second Embodiment)
A second embodiment of the present invention is shown in FIGS. The second embodiment is detected by a pressure sensor 26a provided between the accumulator 25 and the compressor 21 as shown in FIG. 5 in addition to the high-pressure side pressure PH of the refrigerant in the first embodiment. Using the low-pressure side pressure PL of the refrigerant, the difference between the high-pressure side pressure PH and the low-pressure side pressure PL, that is, the high-low pressure difference (corresponding to the difference between the high and low in the present invention) PH-PL = ΔP as one characteristic value Is to do.

  Here, the control device 3 performs start control based on the flowchart shown in FIG. Note that the flowchart shown in FIG. 6 is obtained by changing step S130 to step S131 with respect to the flowchart described with reference to FIG. 2 in the first embodiment.

  Hereinafter, the control content performed by the control device 3 will be described with a focus on the changed step S131. First, the control device 3 calculates the target high pressure side pressure PHm in step S100, and reads the high pressure side pressure PHn in step S111.

  Next, in step S120, it is determined whether or not the current high pressure side pressure PHn has reached the target high pressure side pressure PHm, and if not, the process proceeds to step S131.

  In step S131, the throttle amount ΔZ of the expansion valve 23 is calculated. Here, the throttle amount ΔZ is determined according to the current high / low pressure difference PHn−PLn = ΔPn and the change rate ΔPn−ΔPb of the high / low pressure difference from before the unit time to the current time.

  The change rate ΔPn−ΔPb of the high / low pressure difference will be further described in detail with reference to FIG. Assuming that the current high pressure side pressure is PHn, the low pressure side pressure is PLn, the high pressure side pressure before a predetermined time is PHb, and the low pressure side pressure is PLb, the high pressure difference between the current time and the predetermined time ago is PHn−PLn ( = ΔPn) and PHb−PLb (= ΔPb). The rate of change of the high / low pressure difference per predetermined time (from a predetermined time before to the current time) is obtained as ΔPn−ΔPb.

  Then, the aperture amount ΔZ is calculated (selected) based on the aperture amount calculation map shown in FIG. Here, the aperture amount calculation map is such that the aperture amount ΔZ is related by the above-described high / low pressure difference ΔPn and the change rate ΔPn−ΔPb of the high / low pressure difference, and the aperture amount ΔZ decreases as the high / low pressure difference ΔPn decreases. The smaller the rate of change ΔPn−ΔPb of the high / low pressure difference is, the larger it is.

  Thereafter, as in the first embodiment, the current valve opening degree Zn is read (step S140), the target valve opening degree Zm and the corrected throttle amount ΔZh are calculated respectively (steps S150 and S160), and the correction is made in step S170. The valve opening Z of the expansion valve 23 is varied (throttle) by the amount of restriction ΔZh, and the process returns to step S100 and the above control is repeated. If it is determined in step S120 that the high pressure side pressure PH has reached the target high pressure side pressure PHm, the start control is stopped.

  Thereby, similarly to the first embodiment, the throttle amount ΔZ and the corrected throttle amount ΔZh can be calculated, and the time until the high pressure side pressure PH of the refrigerant reaches the target high pressure side pressure PHm can be further shortened.

  In the present embodiment, the low pressure side pressure PL is detected by the pressure sensor 26a provided between the accumulator 25 and the compressor 21, but not limited to this, the expansion valve 23 and the air heat exchanger 24 You may make it detect between them.

  In addition, the low pressure side temperature of the refrigerant between the accumulator 25 and the compressor 21 (the suction side of the compressor 21) or between the expansion valve 23 and the air heat exchanger 24 (the inlet side of the air heat exchanger 24) is set. The low pressure side pressure PL corresponding to the low pressure side temperature may be detected and used.

  In addition, the high / low pressure difference ΔPn is used as the characteristic value related to the heating capacity of the refrigerant with respect to water. Instead, the high pressure side temperature of the refrigerant (the temperature between the compressor 21 and the water refrigerant heat exchanger 22 or the water The temperature between the refrigerant heat exchanger 22 and the expansion valve 23) and the low-pressure side temperature of the refrigerant (the temperature between the accumulator 25 and the compressor 21 or the temperature between the expansion valve 23 and the air heat exchanger 24). It is good also as a high-low temperature difference which becomes a difference with this.

(Third embodiment)
A third embodiment of the present invention is shown in FIG. 3rd Embodiment changes the expansion valve 23 with respect to the said 1st, 2nd embodiment. That is, in the first and second embodiments, the heat pump device 2 generally reduces the refrigerant in an enthalpy manner by the expansion valve 23, and almost all of the refrigerant flowing out of the expansion valve 23 flows into the air heat exchanger 24. However, the present invention can also be applied to a so-called ejector cycle.

  That is, as shown in FIG. 9, in the heat pump device 2, a nozzle part 27 a whose degree of opening can be changed to convert the pressure energy of the high-pressure refrigerant flowing out of the water-refrigerant heat exchanger 22 into velocity energy and decompress the refrigerant, and The gas-phase refrigerant evaporated in the air heat exchanger 24 is sucked by the high-speed refrigerant flow injected from the nozzle part 27a, and the refrigerant injected from the nozzle part 27a and the gas-phase refrigerant sucked from the air heat exchanger 24 are mixed. An ejector 27 having a booster 27b that boosts the pressure of the refrigerant by converting the velocity energy into pressure energy, and supplies the liquid-phase refrigerant out of the refrigerant that has flowed out of the ejector 27 to the air heat exchanger 24. Even in an ejector cycle in which a gas-phase refrigerant is supplied to the compressor 21, the nozzle portion 27a of the ejector 27 is regarded as a pressure reducing device and the present invention is applied. Possible it is.

  In the ejector cycle, the refrigerant flows through the air heat exchanger 24 as the refrigerant flows through the main circuit connecting the compressor 21, the water / refrigerant heat exchanger 22, and the ejector 27. Therefore, the refrigerant characteristic value (for example, the high pressure side pressure PH) reaches the target value (for example, the target high pressure side pressure PHm) in a short time, so that the refrigerant flow rate to both the main circuit and the air heat exchanger 24 increases. It can be secured and the heating capacity can be secured quickly.

  In the ejector cycle, when the low pressure side temperature is used as the characteristic value of the refrigerant, the temperature sensor 28 (indicated by the broken line in FIG. 9) is connected between the accumulator 25 and the compressor 21, and between the accumulator 25 and the air radiator 24. In the meantime, it may be provided in at least one place between the ejector 27 and the accumulator 25 (ejector outlet) to detect the low temperature side temperature.

(Other embodiments)
In each of the above embodiments, when calculating the corrected aperture amount ΔZh (step S160), the predetermined corrected aperture amount ΔZhmax may be determined in advance, and the predetermined corrected aperture amount ΔZhmax may be regulated as the upper limit value of the corrected aperture amount ΔZh. Thereby, the rapid increase of the high-pressure side pressure PH of the refrigerant can be suppressed, and damage to the compressor 21 itself and various devices (22, 23, 26, 27) on the high-pressure side in the heat pump device 2 can be prevented.

  In each of the above embodiments, the water in the lower part of the hot water storage tank 1 is heated by the heat pump device 2 and stored in the upper part of the hot water storage tank 1 as high temperature hot water. It may be heated by the heat pump device 2 before being introduced into the tank 1 and then stored in the hot water storage tank 1. The present invention can also be applied to a hot water supply apparatus that does not include the hot water storage tank 1 and that heats water supplied from the outside with the heat pump device 2 to form hot water and supplies the hot water without storing it.

  Moreover, in each said embodiment, although the heat pump apparatus 2 comprised what is called a supercritical heat pump cycle which pressurizes a refrigerant | coolant more than a critical pressure with the compressor 21, it is not limited to a supercritical heat pump cycle. Moreover, although the refrigerant | coolant was the carbon dioxide, it is not limited to this. Other refrigerants such as so-called Freon may be used.

It is a schematic diagram which shows schematic structure of the heat pump type hot water supply apparatus in 1st Embodiment. It is a flowchart used for starting control which the control apparatus in 1st Embodiment performs. It is a time chart which shows the high pressure side pressure PH and valve opening degree Z in 1st Embodiment. 6 is a map for calculating an aperture amount ΔZ at the time of start control in the first embodiment. It is a schematic diagram which shows schematic structure of the heat pump type hot water supply apparatus in 2nd Embodiment. It is a flowchart used for starting control which the control apparatus in 2nd Embodiment performs. It is a time chart which shows the pressure P in 2nd Embodiment. 10 is a map for calculating an aperture amount ΔZ at the time of start-up control in the second embodiment. It is a schematic diagram which shows schematic structure of the heat pump type hot water supply apparatus in 3rd Embodiment.

Explanation of symbols

2 Heat pump device (heat pump cycle)
3 Control device (control means)
17 Circulation circuit (hot water supply circuit)
21 Compressor 22 Water refrigerant heat exchanger 23 Expansion valve (pressure reducer)
24 Air heat exchanger 27 Ejector 27a Nozzle part 27b Booster part 100 Heat pump hot water supply device

Claims (11)

A heat pump cycle (2) in which a compressor (21), a water-refrigerant heat exchanger (22), a decompressor (23), and an air heat exchanger (24) are sequentially connected, and the refrigerant flows therein.
Control means (3) for controlling the operation of the compressor (21) and the valve opening (Z) of the pressure reducer (23);
A hot water supply circuit (17) through which water for hot water supply flows through the water-refrigerant heat exchanger (22),
In the heat pump hot water supply apparatus in which the water for hot water supply is heated by the refrigerant in the water refrigerant heat exchanger (22),
When the control means (3) controls the characteristic value (PH) related to the heating capacity of the refrigerant with respect to the hot water supply water to the target value (PHm) after starting the compressor (21),
The absolute value of the difference (PHm−PHn) between the target value (PHm) and the current characteristic value (PHn), which is the throttle amount (ΔZ) of the pressure reducer (23) to be throttled after a predetermined time from the present time Is determined to be larger as the absolute value of the change rate (ΔPHn−ΔPHb) from a predetermined time before the difference (PHm−PHn) to the present time is smaller.
The determined throttle amount (ΔZ) is obtained by calculating the difference between the current valve opening (Zn) at the current time and the target valve opening (Zm) of the pressure reducer (23) corresponding to the target value (PHm) (Zn / Zm) is corrected as a corrected aperture amount (ΔZh) so as to increase as Zm) increases.
The heat pump type hot water supply apparatus, wherein the current valve opening degree (Zn) is varied using the corrected throttle amount (ΔZh).   The heat pump type hot water supply apparatus according to claim 1, wherein the control means (3) uses a high pressure side pressure (PH) as the characteristic value (PH).   The heat pump hot water supply apparatus according to claim 1, wherein the control means (3) uses a high-pressure side temperature as the characteristic value. A heat pump cycle (2) in which a compressor (21), a water-refrigerant heat exchanger (22), a decompressor (23), and an air heat exchanger (24) are sequentially connected, and the refrigerant flows therein.
Control means (3) for controlling the operation of the compressor (21) and the valve opening (Z) of the pressure reducer (23);
A hot water supply circuit (17) through which water for hot water supply flows through the water-refrigerant heat exchanger (22),
In the heat pump hot water supply apparatus in which the water for hot water supply is heated by the refrigerant in the water refrigerant heat exchanger (22),
When the control means (3) controls the pressure (P) or temperature related to the heating capacity of the refrigerant with respect to the hot water supply water to a target value (PHm) after starting the compressor (21),
The throttle amount (ΔZ) of the pressure reducer (23) to be throttled from the present time to a predetermined time later is determined by the difference between the high pressure side characteristic value (PHn) and the low pressure side characteristic value (PLn) of the refrigerant (PHn−PLn). ) Is smaller, and the rate of change (ΔPn−ΔPb) from a predetermined time before the present height difference (PHn−PLn) to the present time is smaller, it is determined to increase.
The determined throttle amount (ΔZ) is obtained by calculating the difference between the current valve opening (Zn) at the current time and the target valve opening (Zm) of the pressure reducer (23) corresponding to the target value (PHm) (Zn / Zm) is corrected as a corrected aperture amount (ΔZh) so as to increase as Zm) increases.
The heat pump type hot water supply apparatus, wherein the current valve opening degree (Zn) is varied using the corrected throttle amount (ΔZh).   The control means (3) uses a high pressure side pressure (PHn) as the high pressure side characteristic value (PHn) and a low pressure side pressure (PLn) as the low pressure side characteristic value (PLn). The heat pump type hot water supply apparatus described.   The heat pump hot water supply apparatus according to claim 4, wherein the control means (3) uses a high pressure side temperature as the high pressure side characteristic value and a low pressure side temperature as the low pressure side characteristic value.   In the detection of the low pressure side pressure (PLn), the control means (3) detects the refrigerant inlet temperature of the air heat exchanger (24), the suction side temperature of the compressor (21), the decompressor ( The heat pump type hot water supply apparatus according to claim 5, wherein at least one of the outlet temperature of the ejector when the nozzle portion (27a) of the ejector (27) is used as 23).   8. The control device according to claim 1, wherein the control unit restricts the predetermined correction aperture amount (ΔZhmax) as an upper limit value when correcting the aperture amount (ΔZ). 9. Heat pump water heater. A nozzle (27a) that decompresses and expands the high-pressure refrigerant that has flowed out of the water-refrigerant heat exchanger (22), refrigerant that is injected from the nozzle (27a), and air that is sucked from the air heat exchanger (24). An ejector (27) having a pressure increasing part (27b) for increasing the pressure of the refrigerant by mixing with a phase refrigerant,
The heat pump type hot water supply device according to any one of claims 1 to 8, wherein the decompressor (23) includes the nozzle portion (27a).   The heat pump type according to any one of claims 1 to 9, wherein the compressor (21) compresses and discharges the refrigerant in the heat pump cycle (2) to a critical pressure or more. Hot water supply device.   The heat pump hot water supply apparatus according to claim 10, wherein the refrigerant is carbon dioxide.

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