JP5582294B2 - Hot water / hot water heating system with dual refrigeration cycle - Google Patents

Description

  The present invention has a high-source-side refrigeration cycle and a low-source-side refrigeration cycle connected by an inter-refrigerant heat exchanger, and the water in the hot water supply section is water-refrigerant heat exchanger in the high-source-side refrigeration cycle. The present invention relates to a hot water supply / hot water heating apparatus using a dual refrigeration cycle that heats and heats a hot water supply for hot water supply and hot water heating.

  Patent Document 1 has a high-source-side refrigeration cycle and a low-source-side refrigeration cycle connected by an inter-refrigerant heat exchanger, and the water-refrigerant heat exchanger in the hot water storage tank in the high-source-side refrigeration cycle. A hot water supply apparatus that heats and raises the temperature of water to generate hot water is disclosed.

  Hot water in the hot water storage tank can be used for fan convectors and floor heating for hot water heating, but the temperature rises when water is heated with a water-refrigerant heat exchanger in hot water heating and hot water heating. Since the temperature ranges are different, there are the following problems when trying to perform hot water supply and hot water heating in the same refrigeration cycle.

  As an example, assuming that hot water is generated with a heating amount of 5 kW, in the case of heating, when heated to 60 ° C., discharged hot water and radiated at the heating terminal, the hot water is a water-refrigerant with a temperature drop of about 10K. Since the temperature returns to the heat exchanger, the temperature rise range is about 10K, and the water flow rate in the water-refrigerant heat exchanger at that time is about 7.17 liters per minute.

  On the other hand, in the case of hot water supply, since the city water of about 17 ° C. is heated to 80 ° C., the temperature increase range is 63K, and the water flow rate in the water-refrigerant heat exchanger Is approximately 1.19 liters per minute, which is about 1/6 that of hot water heating. In this way, although the hot water temperature and the water flow rate are different between hot water supply and hot water heating, it is found that it is inefficient to realize them in the same refrigeration cycle.

Japanese Patent Application Laid-Open No. 2004-218943

  Therefore, an object of the present invention is to enable efficient operation as a whole by switching the operation of the high-side refrigeration cycle according to the hot water temperature and the water flow rate during hot water supply and hot water heating. It is to provide a hot water supply / hot water heating device based on the original refrigeration cycle.

In order to solve the above problems, the present invention provides a hot water supply unit for hot water supply and / or hot water heating, a first compressor, a first condensing unit, a first expansion valve, and A high-end side refrigerant circuit including a first evaporator, and a low-end side refrigerant circuit including a second compressor, a second condensing unit, a second expansion valve, and a second evaporating unit, A water-refrigerant heat exchanger is provided between the first condensing unit on the original side, and an inter-refrigerant heat exchanger is provided between the first evaporating unit on the high original side and the second condensing unit on the low original side. In the hot water supply / hot water heating device by the provided dual refrigeration cycle,
At least refrigerant heat exchanger is connected in parallel to the high-side refrigerant circuit - in that during hot water supply during the hot water heating as well as have a control means for switching the operation cycle of the high-side refrigerant circuit, the water Two water-refrigerant heat exchanging sections are provided, and the control means is configured to transcritically heat the water in the hot water supply section with the refrigerant sensible heat in the supercritical region during the hot water supply operation cycle of the high-source side refrigerant circuit. Cycle operation, using any one water-refrigerant heat exchange unit during the transcritical cycle operation, and subcritical cycle operation that heats and heats the water in the hot water supply unit with the condensation heat of the refrigerant during warm water heating , Two water-refrigerant heat exchangers are used during the subcritical cycle operation .

Specifically, as described in claim 2 , any one of the water-refrigerant heat exchanging parts used during the transcritical cycle operation includes a refrigerant flow opening / closing valve and a water passage opening / closing. And a first flow path switching valve for switching the hot water heated by the refrigerant between the hot water supply side and the hot water heating side at the outlet side of the water-refrigerant heat exchanger, The control means closes both the refrigerant flow path on-off valve and the water flow path on-off valve at the time of the transcritical cycle operation, switches the first flow path switching valve to the hot water supply side, and at the time of the subcritical cycle operation. The refrigerant flow path opening / closing valve and the water flow path opening / closing valve are both opened, and the first flow path switching valve is switched to the hot water heating side.

Further, the present invention is, as described in claim 3, hot water and / or a hot water supply unit for hot water heating, the first compressor, a first condenser portion, the first expansion valve and the first evaporator And a low-side refrigerant circuit including a second compressor, a second condensing unit, a second expansion valve, and a second evaporation unit, and the hot water supply unit and the high-side side first circuit A water-refrigerant heat exchanger is provided between the first condensing unit, and an inter-refrigerant heat exchanger is provided between the first high-evaporating unit and the second low-side condensing unit. In hot water supply / hot water heating system with dual refrigeration cycle,
Control means for switching the operation cycle of the high-side refrigerant circuit between hot water supply and hot water heating, and the water-refrigerant heat exchanger is connected in series to the high-source side refrigerant circuit. Two water-refrigerant heat exchanging sections, and the control means is a transcritical cycle for heating and heating the water in the hot water supply section with the refrigerant sensible heat in the supercritical region when supplying hot water. During the transcritical cycle operation, one of the water-refrigerant heat exchange units is used, and during warm water heating , the water in the warm water supply unit is heated and heated with the condensation heat of the refrigerant. A mode in which two water-refrigerant heat exchangers are used during critical cycle operation is also included.

Specifically, as described in claim 4 , among at least two water-refrigerant heat exchange units connected in series to the high-side refrigerant circuit, the upstream side in the refrigerant flow direction. A bypass pipe is provided between the refrigerant inlet side and the refrigerant outlet side of the water-refrigerant heat exchange part, and a refrigerant flow path is provided on the refrigerant inlet side with the water-refrigerant heat exchange part side and the bypass pipe. A second flow path switching valve for switching to one of the two sides is provided, and the hot water supply unit passes from the downstream water-refrigerant heat exchange unit side to the upstream water-refrigerant heat exchange unit to the hot water heating side. The first water passage through which the hot water flows, and between the downstream water-refrigerant heat exchanger and the upstream water-refrigerant heat exchanger through the third flow path switching valve to the hot water supply side. The water flow circuit, and the control means sets the second flow path switching valve in the transcritical cycle operation. In addition to switching to the circulation pipe side, the third flow path switching valve is switched to the second water flow circuit side, and the second flow path switching valve is switched to the water-refrigerant heat exchange side during the subcritical cycle operation. At the same time, the third flow path switching valve is switched to the first water flow circuit side.

In the present invention, as described in claim 5 , the control means closes the opening of the high-side first expansion valve when switching from the subcritical cycle operation to the transcritical cycle operation. When the rotational speed of the first high-side compressor is increased in a state of being squeezed to a predetermined side, and the lowering of the evaporation pressure at the first high-evaporator is larger than a predetermined value, The rotational speed of the second compressor on the lower side and / or the opening of the second expansion valve are controlled to be predetermined.

In addition, as described in claim 6 , the control means sets the opening of the high-side first expansion valve to the open side when switching from the transcritical cycle operation to the subcritical cycle operation. When the rotational speed of the first compressor on the high power side is lowered in a state where it is increased to a predetermined level, and the decrease in the evaporation pressure in the first evaporator on the high power side is smaller than a predetermined value, the low power The rotational speed of the second compressor on the side and / or the opening of the second expansion valve are controlled to be predetermined.

  According to the present invention, at the time of hot water supply where the temperature of the hot water is high and the flow rate of water is low, the operation cycle of the high-side refrigerant circuit heats and heats the water in the hot water supply unit with the refrigerant sensible heat in the supercritical region. On the other hand, during hot water heating where the tapping temperature is lower than that of the hot water supply and the flow rate of water is higher than that of the hot water supply, the operation cycle of the high-side refrigerant circuit heats up the water in the hot water supply section with the heat of condensation of the refrigerant. By switching to the warming subcritical cycle operation, an efficient operation as a whole can be performed.

The (a) ph diagram at the time of subcritical cycle operation adopted in the present invention, (b) the ph diagram at transcritical cycle operation. The refrigeration circuit diagram which shows 1st Embodiment of this invention. The operation | movement flowchart of the said 1st Embodiment. The freezing circuit diagram which shows 2nd Embodiment of this invention. The operation | movement flowchart of the said 2nd Embodiment. The control flowchart at the time of the operation | movement switching to the transcritical cycle in each said embodiment. The control flowchart at the time of the operation | movement switching to the subcritical cycle in each said embodiment.

  Next, an embodiment of the present invention will be described with reference to FIGS. 1 to 7, but the present invention is not limited to this.

  Transcritical cycle operation allows heat exchange between refrigerant and water with a small temperature difference, and a large enthalpy difference can be ensured, so water can be heated from a low temperature to a high temperature. It can be said that it is suitable. On the other hand, if the temperature of the return hot water is high and sufficient heat dissipation is not performed, the compressor discharge temperature will be very high to ensure the same enthalpy difference as hot water supply. Since the intake refrigerant may be in a two-phase state, it is not very suitable for hot water heating.

  On the other hand, in the case of subcritical cycle operation, a large difference in latent heat enthalpy at a high temperature can be secured in the condensation region, so that it can be said that it is suitable for heating and heating with a small heating range such as hot water heating.

  Therefore, in the present invention, the high-side refrigeration cycle is set to a subcritical cycle operation according to the ph diagram shown in FIG. 1 (a) during hot water heating, whereas in the hot water supply, FIG. The operation is switched to the transcritical cycle operation along the ph diagram shown in (b).

  Therefore, as shown in FIG. 2, the first embodiment includes, as a basic configuration, a first refrigerant circuit 10 that is used as a high-side refrigeration cycle, and a second refrigerant circuit 20 that is used as a low-side refrigeration cycle. And a hot water supply unit 30 for supplying hot water to the hot water supply terminal and the hot water heating terminal.

  The refrigerant circulation system 10a of the first refrigerant circuit 10 on the higher element side includes a compressor 11, a condensing unit 12, an expansion valve 13, an evaporation unit 14, and an accumulator 15, and similarly, the second refrigerant on the lower element side. The refrigerant circulation system 20a of the circuit 20 also includes a compressor 21, a condensing unit 22, an expansion valve 23, an evaporation unit (air-refrigerant heat exchanger) 24, and an accumulator 25.

  The hot water supply unit 30 includes a hot water storage tank 31 and supplies hot water in the hot water storage tank 31 to a hot water supply terminal such as a faucet plug (not shown) and a heating terminal 32. In this embodiment, the heating terminal 32 is a hot water fan vector, but may be a floor heating panel or a radiator.

  The high-side condensing unit 12 and the hot water supply unit 30 are thermally connected via the water-refrigerant heat exchanger A, and the high-side evaporating unit 14 and the low-side condensing unit 22 are connected to each other. The heat exchanger B is thermally connected via the inter-refrigerant heat exchanger B.

  In this first embodiment, the water-refrigerant heat exchanger A has a first water-refrigerant heat exchange part A1 and a second water-refrigerant heat exchange part A2, and these water-refrigerant heat exchange parts A1, A2 is connected in parallel to the refrigerant circulation system 10a.

  Accordingly, the condensing unit 12 is also divided into a first condensing unit 121 and a second condensing unit 122, and the first condensing unit 121 is disposed in the first water-refrigerant heat exchange unit A <b> 1 and the second condensing unit 122. Is disposed in the second water-refrigerant heat exchange section A2.

  The opening / closing valve 16 is provided on the refrigerant inlet side of the first condensing part 121, and the refrigerant outlet sides of the first and second condensing parts 121, 122 merge to reach the expansion valve 13.

  The hot water supply unit 30 has an outward piping 33 drawn from the bottom side of the hot water storage tank 31, and the outward piping 33 includes a flow path switching valve 34 and a water supply pump 35 for water circulation.

  The flow path switching valve 34 is a three-way valve having two inflow ports 34a and 34b that are alternately switched and one outflow port 34c. The forward piping 33 is connected to one inflow port 34a, and the outflow port 34c is connected to the outflow port 34c. The suction side of the water pump 35 is connected.

  The discharge-side piping of the water supply pump 35 is branched into a bifurcated water passage, one of the water passages 331 is passed through the first water-refrigerant heat exchanger A1, and the other water passage 332 is in the second water-refrigerant heat exchange. It passes through part A2. One water passage 331 is provided with an on-off valve 333.

  In FIG. 2, the flow direction of the refrigerant flowing through the condensing units 121 and 122 is from the top to the bottom, whereas the flow direction of water flowing through the water passages 331 and 332 is from the bottom to the top. And the flow of water is countercurrent.

  The other end sides of the water passages 331 and 332 join together and reach the passage switching valve 37 via the joining pipe 334. The flow path switching valve 37 is a three-way valve having one inflow port 37a and two outflow ports 37b and 37c that are switched alternately, and the junction pipe 334 is connected to the inflow port 37a.

  One outlet 37b is connected to one end of a hot water circulation system 38 including the heating terminal 32, and the other outlet 37c is connected to a return pipe 39 that is returned to the upper part of the hot water storage tank 31. The other end of the hot water circulation system 38 is connected to the remaining inlet 34 b of the flow path switching valve 34.

  The hot water supply / hot water heating apparatus according to the first embodiment performs control necessary for switching the high-side refrigeration cycle (first refrigerant circuit 10) to subcritical cycle operation during hot water heating and switching to transcritical cycle operation during hot water supply. The control means 40 to perform is provided.

  Thereby, at the time of hot water heating operation, the water-refrigerant heat exchanger is switched to two or more so as to be able to cope with a large amount of water supply, and at the time of hot water supply where the amount of water supply is smaller than that of hot water heating, basically one water-refrigerant heat Correspond with an exchange.

  As the control means 40, a CPU, a microcomputer or the like is used, and the rotation speeds of the compressors 11 and 21, the opening degrees of the expansion valves 13 and 23, the on-off valves 16 and 333, the flow path switching valves 34 and 37, and the water supply pump 35. Control the amount of water flow.

  Next, an example of the operation of the first embodiment will be described. It should be noted that at the time of hot water supply, 80 ° C. hot water is used and the temperature of 17 ° C. is heated by 63K, and at the time of hot water heating, the hot water is heated at 60 ° C. and the return hot water of 50 ° C. is heated by 10K.

  First, at the time of hot water heating, the on-off valve 16 of the high-source side refrigerant circuit 10 and the on-off valve 333 of the water passage 331 are opened, and refrigerant and water are supplied to the first and second water-refrigerant heat exchange units A1, A2. Make it flow.

  The water supply pump 35 is started by closing the inlet 34a side of the flow path switching valve 34, opening the inlet 34b side, closing the outlet 37c side of the flow path switching valve 37, and opening the outlet 37b side. Then, the high-end side refrigerant circuit 10 is set to the subcritical cycle operation, hot water having a target temperature of 60 ° C. is generated in the water-refrigerant heat exchange units A 1, A 2, and the hot water flows to the hot water circulation system 38 including the heating terminal 32.

  On the other hand, at the time of hot water supply, the on-off valve 16 of the high-source side refrigerant circuit 10 and the on-off valve 333 of the water passage 331 are closed, and neither refrigerant nor water flows through the first water-refrigerant heat exchange unit A1, The refrigerant and water flow only in the second water-refrigerant heat exchange part A2.

The water supply pump 35 is started by opening the inlet 34a side of the flow path switching valve 34, closing the inlet 34b side, opening the outlet 37c side of the flow path switching valve 37, and closing the outlet 37b side. the high-side refrigerant circuit 10 as a transcritical cycle operation, the second water - to produce hot water of targets temperature 80 ° C. in the refrigerant heat exchanger A2, without supplying the the hot water to the hot water circulation system 38, return piping It returns to the hot water storage tank 31 through 39.

  Thus, hot water of about 80 ° C. is stored in the hot water storage tank 31, but it is preferable that the hot water tank 31 is appropriately mixed with city water (tap water) to adjust the temperature to about 38 to 45 ° C. to supply hot water. Moreover, what is necessary is just to supply city water to the hot water storage tank 31 about the amount of water reduced by hot water supply.

An example of operating points during the subcritical cycle operation and the transcritical cycle operation of the high-source side refrigerant circuit 10 is shown in Table 1 below.

Further, in both the sub-critical cycle operation and the transcritical cycle operation of the high-source side refrigerant circuit 10, the low-source side refrigerant circuit 20 is operated under a predetermined condition. Shown in

In addition, Table 3 shows an example of operating conditions of the high-side refrigerant circuit 10 and the low-side refrigerant circuit 20 at the operating points in Tables 1 and 2 above.

  Moreover, in the said 1st Embodiment, the switching state of each valve 16,34,37,333 at the time of hot water supply and warm water heating and the operation switching state of the water supply amount of the water supply pump 35 are shown in the flowchart of FIG. According to this, during the hot water supply operation (transcritical cycle operation), the water supply amount of the water supply pump 35 is reduced, and during the hot water heating (subcritical cycle operation), the water supply amount of the water supply pump 35 is increased. Yes.

  Next, a second embodiment of the present invention will be described with reference to FIG. Also in the second embodiment, the water-refrigerant heat exchanger A includes the first water-refrigerant heat exchange part A1 and the second water-refrigerant heat exchange part A2. A different point is that the first water-refrigerant heat exchange part A1 and the second water-refrigerant heat exchange part A2 are incorporated in series in the refrigerant circulation circuit 10a on the higher side. Other configurations may be the same as those in the first embodiment.

  The first water-refrigerant heat exchange unit A1 is disposed upstream of the refrigerant flow direction of the high-side refrigerant circulation circuit 10a as a reference, and the second water-refrigerant heat exchange unit A2 includes the first water-refrigerant heat exchange unit A2. It arrange | positions in the downstream of heat exchange part A1.

  According to the second embodiment, the first condensing unit 121 and the second condensing unit 122 are arranged in series between the discharge side of the compressor 11 and the expansion valve 13. A bypass pipe 18 is connected between the refrigerant inlet side and the refrigerant outlet side, and a flow path switching valve 17 is provided on the refrigerant inlet side.

  The flow path switching valve 17 is a three-way valve having one inflow port 17a and two outflow ports 17b and 17c that are alternately switched, and the discharge side of the compressor 11 is connected to the inflow port 17a. The bypass pipe 18 is connected to the outlet 17b, and the first condenser 121 is connected to the other outlet 17c.

  On the water flow side, the water flow path 331 and the water flow path 332 are connected in series, and a flow path switching valve 36 is provided therebetween. As the flow path switching valve 36, a three-way valve having one inflow port 36a and two outflow ports 36b and 36c that are alternately opened and closed is used.

  A water passage 332 including the inside of the second water-refrigerant heat exchange part A2 is connected to the inlet 36a that is upstream of the flow path switching valve 36, and to the outlet 36b that is downstream of the flow path switching valve 36. The return pipe 39 is connected, and the other outflow port 36c is connected with a downstream water passage 331 on the water passage side through the first water-refrigerant heat exchange section A1. The outlet side of the water passage 331 is connected to the hot water circulation system 38.

  Next, the operation of the second embodiment will be described. Here again, as in the first embodiment, 80 ° C. hot water is used for hot water supply, and 17 ° C. water is heated for 63K, and 60 ° C. hot water is used for hot water heating, and 50 ° C. return hot water is heated for 10K. Shall.

  First, at the time of warm water heating, on the refrigerant circuit side, the outlet 17c of the flow path switching valve is opened and the outlet 17b is closed, and the first condensing unit 121 and the second condensing unit 122 are connected in series.

  On the water flow side, the outlet 36c of the flow path switching valve 36 is opened, the outlet 36b is closed, the water paths 332 and 331 are connected in series, and the inlet 34a side of the flow path switching valve 34 is closed. The inlet 34b side is opened so that warm water flows through the warm water circulation system 38.

  And like the said 1st Embodiment, while starting the water supply pump 35, the high side refrigerant circuit 10 is made into a subcritical cycle operation, and hot water with the target temperature of 60 degreeC is made into water-refrigerant heat exchange part A1, A2. The hot water is generated and flows into the hot water circulation system 38 including the heating terminal 32.

  On the other hand, at the time of hot water supply, on the refrigerant circuit side, the outlet 17b of the flow path switching valve is opened and the outlet 17c is closed, and the refrigerant discharged from the compressor 11 passes through the bypass pipe 18 to the second condensing unit 122. So that the refrigerant does not flow through the first condensing unit 121.

  On the water flow side, the outlet 36c of the flow path switching valve 36 is closed and the outlet 36b is opened so that warm water does not flow through the water passage 331 of the first water-refrigerant heat exchange section A1, and the second water- The hot water is returned from the water passage 332 of the refrigerant heat exchange section A2 to the hot water storage tank 31 via the return pipe 39.

Then, as in the first embodiment, as well as activates the water pump 35, the high-side refrigerant circuit 10 as a transcritical cycle operation, a second water - hot water of targets temperature 80 ° C. In the refrigerant heat exchanger A2 The hot water is generated and returned to the hot water storage tank 31 via the return pipe 39 without flowing into the hot water circulation system 38.

  For reference, in the second embodiment, the switching state of the valves 17, 34, 36 and the operation switching state of the water supply amount of the water pump 35 during hot water supply and hot water heating are shown in the flowchart of FIG. Also in the second embodiment, during the hot water supply operation (transcritical cycle operation), the water supply amount of the water supply pump 35 is reduced, and during hot water heating (during subcritical cycle operation), the water supply amount of the water supply pump 35 is reduced. Has been increased.

  Here, with reference to the control flowchart of FIG. 6, the control operation when switching from the hot water heating operation (subcritical cycle operation) to the hot water supply operation (transcritical cycle operation) in the first and second embodiments will be described ( (See FIG. 1B for the ph diagram).

  First, the opening of the expansion valve (electronic expansion valve) 13 on the high-side (refrigerant circuit 10 side) is narrowed to the closed side by an arbitrary step, and the high-side pressure difference is widened, and then the high-side compression is performed. The rotation speed of the machine 11 is increased.

  As a result, the evaporation pressure in the high-evaporator 14 is lowered, so that the evaporation temperature is lowered, and the condensing pressure on the low-source side (refrigerant circuit 20 side) is pushed down accordingly. This is due to the change in the heat balance position in the inter-refrigerant heat exchanger B because the endothermic amount required on the high-end side has changed.

  Therefore, in order to achieve a heat balance between the high-source side and the low-source side with an efficient pressure, the rotational speed of the low-source side compressor 21 is increased, and the low-source side expansion valve (electronic expansion valve) 23 is increased. It is necessary to adjust the opening degree of the to an optimum state.

  Therefore, in this example, when the evaporation pressure that is standard on the high element side is Pst, and the decrease (Pst-P) of the evaporation pressure P on the high element side is larger than 0.15 MPa, for example (Pst-P> 0.15 MPa) For this, the rotational speed of the low-side compressor 21 is increased, and the opening degree of the expansion valve 23 is adjusted as necessary so that Pst−P ≦ 0.15 MPa.

  After making such adjustment, when the high pressure on the high pressure side is made supercritical, the rotation speed and / or the expansion valve of the high pressure compressor 11 is set so that the critical pressure exceeds 0.5 MPa, for example. The opening degree of 13 is adjusted.

  In addition, while confirming the hot water temperature, the discharge temperature of the high-end compressor 11, etc., the rotational speed and hot water flow rate of the high-end compressor 11 are adjusted to reach the indicated hot water temperature (for example, 80 ° C.). .

  Next, with reference to the control flowchart of FIG. 7, the control operation when switching from the hot water supply operation (transcritical cycle operation) to the hot water heating operation (subcritical cycle operation) in the first and second embodiments will be described ( (See FIG. 1A for the ph diagram).

  First, the opening degree of the high-end side expansion valve 13 is set to the open side by an arbitrary step, and the difference in height of the high-end side pressure is reduced. For example, 60 ° C.).

  Further, the rotational speed of the high-end compressor 11, the opening degree of the expansion valve 13, and the hot water flow rate are adjusted so that the discharge temperature of the high-end compressor 11 is also about + 15K with respect to the condensation temperature. .

  At that time, in order to achieve a heat balance between the high-source side and the low-source side that is the heat source, control is performed to reduce the rotational speed of the low-source-side compressor 21, and the compression ratio of the high-source-side compressor 11 is controlled. It is efficient to set the pressure in the inter-refrigerant heat exchanger B (evaporation pressure on the high element side and condensation pressure on the low element side) so that the compression ratio of the compressor on the low element side is approximately the same. Is preferable.

10 First refrigerant circuit (high-end side)
DESCRIPTION OF SYMBOLS 11 Compressor 12 Condensing part 121 1st condensing part 122 2nd condensing part 13 Expansion valve 14 Evaporating part 16 On-off valve 20 2nd refrigerant circuit (low original side)
DESCRIPTION OF SYMBOLS 21 Compressor 22 Condensing part 23 Expansion valve 24 Evaporating part 30 Hot water supply part 31 Hot water storage tank 32 Heating terminal 33 Outward piping 331,332 Water passage 333 On-off valve 34,36,37 Channel switching valve (three-way valve)
35 Water Pump 38 Hot Water Circulation System 39 Return Pipe 40 Control Unit A Water-Refrigerant Heat Exchanger A1 First Water-Refrigerant Heat Exchanger A2 Second Water-Refrigerant Heat Exchanger B Inter-Refrigerant Heat Exchanger

Claims (6)

A hot water supply unit for hot water supply and / or hot water heating, a high-side refrigerant circuit including a first compressor, a first condensing unit, a first expansion valve and a first evaporating unit, a second compressor, and a second condensing unit , A low-side refrigerant circuit including a second expansion valve and a second evaporator, and a water-refrigerant heat exchanger is provided between the hot water supply unit and the high-side first condensing unit, In the hot water supply / hot water heating device by the dual refrigeration cycle in which the inter-refrigerant heat exchanger is provided between the high-evaporator side first evaporator and the low-source side second condenser unit,
At least refrigerant heat exchanger is connected in parallel to the high-side refrigerant circuit - in that during hot water supply during the hot water heating as well as have a control means for switching the operation cycle of the high-side refrigerant circuit, the water With two water-refrigerant heat exchangers,
The control means, the operating cycle of the high-side refrigerant circuit, at the time of hot water and transcritical cycle operation for heating heating water in the hot water supply unit with refrigerant sensible heat of supercritical range, any at the time of the transcritical cycle operation One water-refrigerant heat exchange unit is used, and in the hot water heating , the water in the hot water supply unit is heated and heated by the heat of condensation of the refrigerant, and in the subcritical cycle operation, two water-refrigerants are used. A hot water supply / hot water heating device using a dual refrigeration cycle, characterized by using a heat exchange section . The water-refrigerant heat exchanger used in the transcritical cycle operation is provided with a refrigerant flow path opening / closing valve and a water flow path opening / closing valve, and the water-refrigerant heat exchanger. A first flow path switching valve for switching the hot water heated by the refrigerant between the hot water supply side and the hot water heating side is provided on the outlet side of the refrigerant, and the control means is for the refrigerant flow path during the transcritical cycle operation. Both the on-off valve and the water passage on-off valve are closed, the first flow path switching valve is switched to the hot water supply side, and the refrigerant flow on-off valve and the water passage on-off valve are both connected during the subcritical cycle operation. The hot water supply / hot water heating apparatus with a dual refrigeration cycle according to claim 1 , wherein the first flow path switching valve is switched to a hot water heating side while being opened. A hot water supply unit for hot water supply and / or hot water heating, a high-side refrigerant circuit including a first compressor, a first condensing unit, a first expansion valve and a first evaporating unit, a second compressor, and a second condensing unit , A low-side refrigerant circuit including a second expansion valve and a second evaporator, and a water-refrigerant heat exchanger is provided between the hot water supply unit and the high-side first condensing unit, In the hot water supply / hot water heating device by the dual refrigeration cycle in which the inter-refrigerant heat exchanger is provided between the high-evaporator side first evaporator and the low-source side second condenser unit,
Control means for switching the operation cycle of the high-side refrigerant circuit between hot water supply and hot water heating, and the water-refrigerant heat exchanger is connected in series to the high-source side refrigerant circuit. With two water-refrigerant heat exchangers,
The control means sets the operation cycle of the high-side refrigerant circuit as a transcritical cycle operation in which the water in the hot water supply section is heated and heated with sensible heat in the supercritical region during hot water supply. A single water-refrigerant heat exchange unit is used, and in the hot water heating , the water in the hot water supply unit is heated and heated by the condensation heat of the refrigerant, and in the subcritical cycle operation, two water-refrigerant heats are used. water heating and hot water heating system by two-way refrigeration cycle you, characterized by using a replacement unit. Of the at least two water-refrigerant heat exchange units connected in series to the high-source side refrigerant circuit, the refrigerant inlet side and the refrigerant outlet side of the upstream water-refrigerant heat exchange unit in the refrigerant flow direction A bypass pipe is provided between them, and a second flow path switching valve for switching the refrigerant flow path to either the water-refrigerant heat exchange section side or the bypass pipe side is provided on the refrigerant inlet side. The hot water supply unit includes a first water flow circuit in which hot water flows from the downstream water-refrigerant heat exchange unit side to the hot water heating side through the upstream water-refrigerant heat exchange unit, and the downstream water -Having a second water flow circuit from the refrigerant heat exchange part and the upstream water-refrigerant heat exchange part to the hot water supply side via the third flow path switching valve;
In the transcritical cycle operation, the control means switches the second flow path switching valve to the bypass piping side, switches the third flow path switching valve to the second water flow circuit side, and controls the subcritical cycle. 4. The switch according to claim 3 , wherein, during operation, the second flow path switching valve is switched to the water-refrigerant heat exchange section side, and the third flow path switching valve is switched to the first water flow circuit side. Hot water supply / hot water heating system with dual refrigeration cycle. The control means, when switching from the subcritical cycle operation to the transcritical cycle operation, with the opening of the high expansion side first expansion valve narrowed to a close side to a predetermined value, When the rotation speed of the first compressor is increased and the decrease in the evaporation pressure in the first evaporation section on the higher side is larger than a predetermined value, the rotation speed of the second compressor on the lower side and / or The hot water supply / hot water heating device with a dual refrigeration cycle according to claim 1 or 3 , wherein the opening of the second expansion valve is controlled to a predetermined value. When switching from the transcritical cycle operation to the subcritical cycle operation, the control means is configured to increase the opening of the first high-side expansion valve to a predetermined value while opening the first high-side first expansion valve. When the rotation speed of the first compressor is reduced and the decrease in the evaporation pressure in the first evaporation section on the high-source side is smaller than a predetermined value, the rotation speed and / or the second rotation of the second compressor on the low-element side is reduced. The hot water supply / hot water heating device by the dual refrigeration cycle according to claim 1 or 3 , wherein the opening degree of the two expansion valves is controlled to a predetermined value.

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