JP2012215353A - Dual refrigeration cycle device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dual refrigeration cycle device having low-temperature side and high-temperature side refrigeration cycles that operate using different compressors, thereby increasing input energy necessary for the operation and energy efficiency.SOLUTION: The dual refrigeration cycle device includes: a water-heat exchanger for heat-exchanging the refrigerant of a high-temperature side refrigeration cycle with water received from the outside; water temperature detection means for detecting the temperature of the water received from the outside; external temperature detection means for detecting the temperature of an external heat source; and an operation control means for reducing the operation output of a low-temperature side refrigeration cycle or stopping the operation when the water temperature detected by the water temperature detecting means is higher than the temperature of the external heat source detected by the external temperature detection means, and controlling heat exchange between the high-temperature side refrigerant and the water in the water-heat exchanger.

Description

  Embodiments of the present invention relate to a binary refrigeration cycle apparatus.

In a refrigeration cycle apparatus such as an air conditioner or a heat pump water heater, a binary refrigeration cycle apparatus including a low temperature side refrigeration cycle and a high temperature side refrigeration cycle may be used to supply high temperature heat to the use side.
The low temperature side refrigeration cycle and the high temperature side refrigeration cycle of the binary refrigeration cycle apparatus each have a compressor and an expansion device, and are connected to each other by an intermediate heat exchanger so that heat can be exchanged. And the heat pumped from the low temperature side heat exchanger that is the low temperature side evaporator provided in the low temperature side refrigeration cycle, through the use side heat exchanger that is the high temperature side condenser provided in the high temperature side refrigeration cycle, Higher temperature heat is supplied to the heat utilization equipment.

JP 2002-346403 A

  However, since the above-described two-stage refrigeration cycle apparatus operates the refrigeration cycle on the low temperature side and the high temperature side using separate compressors, the input energy required for the operation is large, and the two more energy efficient. The provision of original refrigeration cycle equipment is desired.

The embodiment of the present invention includes a heat source side heat exchanger that absorbs heat from an external heat source, a low temperature side compressor, and a low temperature side refrigeration cycle in which a low temperature side refrigerant is enclosed, and supplies heat to the user side. A high-temperature side refrigeration cycle that includes a use-side heat exchanger and a high-temperature side compressor and encloses a high-temperature side refrigerant therein, and an intermediate heat exchanger for exchanging heat between the refrigerant of the low-temperature side refrigeration cycle and the high-temperature side refrigeration cycle A two-stage refrigeration cycle apparatus.
This dual refrigeration cycle apparatus includes a water heat exchanger for exchanging heat between the refrigerant of the high temperature side refrigeration cycle and water taken from outside, water temperature detecting means for detecting the temperature of water taken from outside, and an external heat source. When the temperature of the external temperature detection means for detecting the temperature and the temperature of the water detected by the water temperature detection means is higher than the temperature of the external heat source detected by the external temperature detection means, the operation output of the low temperature side refrigeration cycle is reduced. Or, the operation control means for stopping the operation and controlling the heat exchange between the high temperature side refrigerant and the water in the water heat exchanger is provided.

1 is a schematic view of a dual refrigeration cycle apparatus according to a first embodiment of the present invention. The block diagram of the controller which concerns on the 1st Embodiment of this invention. Schematic of the dual refrigeration cycle apparatus according to the second embodiment of the present invention. The block diagram of the controller which concerns on the 2nd Embodiment of this invention.

Embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A first embodiment will be described with reference to FIG.
As shown in FIG. 1, the binary refrigeration cycle apparatus 100 of the present embodiment is configured such that a heat exchange between a low temperature side refrigeration cycle 6 a and a high temperature side refrigeration cycle 6 b can be performed by an intermediate heat exchanger 5.
The low temperature side refrigeration cycle 6a includes a low temperature side compressor 1a, a low temperature side four-way valve 2a connected to the low temperature side compressor 1a via a refrigerant pipe, and heat source side heat exchange that exchanges heat with outdoor air that is an external heat source. The vessel 3 and the low temperature side expansion device 4a are sequentially connected by a refrigerant pipe. Further, an intermediate heat exchanger 5 is connected to the low temperature side four-way valve 2a and the low temperature side expansion device 4a by refrigerant piping.
The heat source side heat exchanger 3 is provided with a blower 11 to promote heat exchange with outdoor air. Further, the heat source side heat exchanger 3 is provided with an outside air temperature sensor 16 that is an external temperature detecting means, and detects the temperature To of the outdoor air sucked into the heat source side heat exchanger 3. Yes.

The high temperature side refrigeration cycle 6b includes a high temperature side compressor 1b, a high temperature side four-way valve 2b connected to the high temperature side compressor 1b via a refrigerant pipe, and an intermediate for heat exchange with the low temperature side refrigerant of the low temperature side refrigeration cycle 6b. The heat exchanger 5, the high temperature side expansion device 4b, and the use side heat exchanger 7 are sequentially connected by refrigerant piping, and the high temperature side refrigeration cycle 6b is configured.
Further, the refrigerant piping of the high temperature side refrigeration cycle 6b branches between the high temperature side four-way valve 2b and the intermediate heat exchanger 5, and between the high temperature side expansion device 4b and the intermediate heat exchanger 5, respectively. A water heat exchanger 13 that exchanges heat between the water and the high-temperature refrigerant is connected in parallel to the intermediate heat exchanger 5. At one end of each of the intermediate heat exchanger 5 and the water heat exchanger 13, there are an intermediate heat exchanger refrigerant flow control valve 12a and a water heat exchanger refrigerant flow control valve 12b for controlling the flow of the high-temperature refrigerant, respectively. Is provided.
Further, the water heat exchanger 13 is connected with a drain pipe 9 through which drainage is circulated, and waste water generated in a factory facility flows in the drain pipe 9 and exchanges heat with the high-temperature side refrigerant. It is like that. On the upstream side of the water heat exchanger 13 of the drain pipe 9, a water temperature sensor 15, which is a water temperature detecting means for detecting the temperature of the waste water flowing through the drain pipe 9, is disposed and provided.

Refrigerants having different characteristics are sealed in the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b, respectively.
The type of refrigerant to be sealed varies depending on the use of the two-stage refrigeration cycle apparatus 100. For example, when the use-side heat exchanger 7 is a water heat exchanger and a high-temperature heat pump water heater for producing hot water close to 90 ° C, The low-temperature side refrigerant used in the low-temperature side refrigeration cycle 6a is preferably a working refrigerant having good performance even at a low outside air temperature (about −15 ° C.) such as R410A, and the high-temperature side refrigerant used in the high-temperature side refrigeration cycle 6b. A working refrigerant having good performance at a high temperature (about 95 ° C.) such as R134a is preferable.
The intermediate heat exchanger 5 exchanges heat between the low-temperature side refrigerant used in the low-temperature side refrigeration cycle 6 a and the high-temperature side refrigerant in the high-temperature side refrigeration cycle 6 b.

The usage-side heat exchanger 7 is connected to a usage-side fluid piping 18 for supplying heat utilization equipment that uses the heat pumped up by the dual refrigeration cycle apparatus 100.
Water, brine, or the like for supplying heat to the heat utilization side device is enclosed in the utilization side fluid pipe 18 and circulated.
In the use side pipe 18, the use side fluid fed by the feed pump 10 flows.

  The dual refrigeration cycle apparatus 100 is provided with an electrical component box 22 for controlling operation. The electrical component box 22 is provided with a controller 23 as operation control means. The controller 23 includes an inverter circuit (not shown) that drives the low temperature side compressor 1a and the high temperature side compressor 1b, the opening degree of the low temperature side expansion device 4a and the high temperature side expansion device 4b, the low temperature side four-way valve 2a, and the high temperature side four-way. The switching of the valve 2b and the opening degree of the intermediate heat exchanger refrigerant flow control valve 12a and the water heat exchanger refrigerant flow control valve 12b are controlled. By these inverter circuit and controller 23, the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are controlled under optimum operating conditions.

As shown in the block diagram of FIG. 2, the controller 23 provided in the dual refrigeration cycle apparatus 100 includes a water temperature sensor 15, an outside air temperature sensor 16, an intermediate heat exchanger refrigerant flow control valve 12a, and a water heat exchange. The refrigerant flow rate control valve 12b is connected.
Here, the intermediate heat exchanger refrigerant flow control valve 12 a and the water heat exchanger refrigerant flow control valve 12 b are controlled by the controller 23.

The flow of the refrigerant during operation of the dual refrigeration cycle apparatus 100 when the waste water temperature Tw detected by the water temperature sensor 15 is equal to or lower than the outside air temperature To (Tw−To ≦ 0 ° C.) is indicated by solid line arrows in FIG.
The intermediate heat exchanger refrigerant flow control valve 12a is opened and the water heat exchanger refrigerant flow control valve 12b is closed, and both the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated.
First, in the low temperature side refrigeration cycle 6a, the low temperature side compressor 1a passes through the low temperature side four-way valve 2a, the low temperature side flow path of the intermediate heat exchanger 5, the low temperature side expansion device 4a, and the heat source side heat exchanger 3 in order. The side four-way valve 2a returns to the low temperature side compressor 1a.
Similarly, in the high temperature side refrigeration cycle 6b, the high temperature side refrigerant compressed by the high temperature side compressor 1b is converted into the high temperature side of the high temperature side four-way valve 2b, the use side heat exchanger 7, the high temperature side expansion device 4b, and the intermediate heat exchanger 5. It passes through the flow path sequentially and returns from the high temperature side four-way valve 2b to the high temperature side compressor 1b.
At this time, the low temperature side refrigerant evaporates in the heat source side heat exchanger 3 and condenses in the low temperature side flow path of the intermediate heat exchanger 5. Further, the high-temperature side refrigerant is condensed in the use-side heat exchanger 7 by supplying warm heat to water or brine flowing in the use-side pipe 18 on the use side, and in the high-temperature side flow path of the intermediate heat exchanger 5. The liquid refrigerant decompressed by the side expansion device 4b evaporates and absorbs the condensation heat of the low temperature side refrigerant as the evaporation heat.

Next, when the temperature Tw of the waste water flowing into the water heat exchanger 13 is higher by 10 ° C. or more than the outside air temperature To (10 ° C. ≦ Tw−To), the low temperature side refrigeration cycle 6a is stopped and the high temperature side refrigeration cycle 6b. Only drive. The flow of the high-temperature side refrigerant at this time is indicated by broken line arrows in FIG.
In response to a command from the controller 23, the intermediate heat exchanger refrigerant flow control valve 12a connected to the intermediate heat exchanger 5 is closed, and the water heat exchanger refrigerant flow control valve 12b connected to the water heat exchanger 13 is closed. Open. And only the high temperature side refrigerating cycle is drive | operated in the state which stopped the low temperature side refrigerating cycle.
In the use side heat exchanger 7, the high temperature side refrigerant is condensed by supplying warm heat to the water in the use side pipe 18 on the use side, and the liquid high temperature side refrigerant decompressed by the high temperature side expansion device 4b is hydrothermal. It absorbs the heat of the wastewater generated in the factory equipment flowing in the exchanger 13 and evaporates.

Next, when the difference between the temperature Tw of the waste water flowing into the water heat exchanger 13 and the outside air temperature To is less than 10 ° C. (0 ° C. <Tw−Ta <10 ° C.), the intermediate heat exchanger refrigerant flow control valve Both 12a and the water heat exchanger refrigerant flow control valve 12b are opened, and both the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated. At this time, the high-temperature side refrigerant flows into both the intermediate heat exchanger 5 and the water heat exchanger 13.
By the command of the controller 23, both the intermediate heat exchanger refrigerant flow control valve 12a and the water heat exchanger refrigerant flow control valve 12b are opened by a predetermined amount, and the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated. The opening degree of the intermediate heat exchanger refrigerant flow control valve 12a and the water heat exchanger refrigerant flow control valve 12b is determined by the temperature of the wastewater flowing into the water heat exchanger 13 detected by the water temperature sensor 15. That is, when the waste water temperature detected by the water temperature sensor 15 is high, the opening degree of the intermediate heat exchanger refrigerant flow control valve 12a is reduced, and the opening degree of the water heat exchanger refrigerant flow control valve 12b is increased. The flow rate of the high-temperature side refrigerant flowing into the water heat exchanger 13 is increased.

  When the waste water temperature Tw detected by the water temperature sensor 15 is equal to or lower than the outside air temperature To (Tw−To ≦ 0 ° C.), both the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated and intermediate heat exchange is performed. The refrigerant refrigerant flow control valve 12a is fully opened and the water heat exchanger refrigerant flow control valve 12b is closed so that the high-temperature refrigerant flows only into the intermediate heat exchanger 5.

  As described above, the intermediate heat exchanger 5 and the water heat exchanger are determined by the difference between the temperature Tw of the wastewater flowing into the heat exchanger 13 detected by the water temperature sensor 15 and the outside air temperature To detected by the outside air temperature sensor 16. By distributing the flow rate of the high-temperature side refrigerant flowing into the refrigerant 13, the operation energy required for the operation of the low-temperature side refrigeration cycle 6a can be minimized, and the dual refrigeration cycle apparatus 100 having higher energy efficiency can be obtained. it can.

  In the first embodiment, the intermediate heat exchanger refrigerant flow control valve 12a has a temperature difference between the outdoor temperature To and the waste water temperature Tw in the range of 0 ° C. to 10 ° C. (0 ° C. <Tw−Ta <10 ° C.). The refrigerant flow control means for changing the opening degree of the water heat exchanger refrigerant flow control valve 12b is used, but the temperature difference condition is changed depending on the type of refrigerant used and the temperature range required for the heat utilization device. Good.

(Second Embodiment)
As shown in FIG. 3, the binary refrigeration cycle apparatus 100 according to the second embodiment includes a low temperature side refrigeration cycle 6 a and a high temperature side refrigeration cycle 6 b as in the dual refrigeration cycle apparatus 100 of the first embodiment. Yes.
Here, as a configuration different from the refrigeration cycle apparatus 100 of the first embodiment, there is a connection form of the water heat exchanger 13. The water heat exchanger 13 of the second embodiment is arranged in series with respect to the intermediate heat exchanger 5 between the intermediate heat exchanger 5 and the high temperature side expansion valve 4b, and is connected to the refrigerant pipe of the high temperature side refrigeration cycle 6b. It is connected. Further, the water heat exchanger 13 is connected in parallel to the drain pipe 9 through which the drainage flows through the flow control three-way valve 14 and the downstream branching portion 17, and the flow path of the flow control three-way valve 14 is switched. Thus, it is controlled whether or not the waste water flows in the water heat exchanger 13. A drainage pump 8 is provided on the downstream side of the downstream branching portion 17, and the flow is performed so that the drainage flows regardless of the drainage flow path.
A water temperature sensor 15 is provided on the upstream side of the flow control three-way valve 14 so as to detect the drainage temperature, and is connected to the controller 23 as shown in the block diagram of FIG. This flow control three-way valve 14 is controlled by a controller 23.

The dual refrigeration cycle apparatus 100 configured as described above is operated as follows.
When the waste water temperature Tw detected by the water temperature sensor 15 is equal to or lower than the outside air temperature To detected by the outside air temperature sensor 16 provided in the heat source side heat exchanger 3, the flow path of the flow control three-way valve 14 is the water heat exchanger. It is switched so that the drainage does not flow into 13. Then, both the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated.
First, in the low temperature side refrigeration cycle 7, the low temperature side compressor 1 sequentially passes through the low temperature side four-way valve 2, the low temperature side flow path of the intermediate heat exchanger 5, the low temperature side expansion device 4, and the heat source side heat exchanger 3. The side four-way valve 2 returns to the low temperature side compressor 1.
Similarly, in the high temperature side refrigeration cycle 6b, the high temperature side refrigerant compressed by the high temperature side compressor 1b is converted into the high temperature side four-way valve 2b, the use side heat exchanger 7, the high temperature side expansion device 4b, the water heat exchanger 13, and the intermediate heat. The high temperature side flow path of the exchanger 5 is sequentially passed, and the high temperature side four-way valve 2b returns to the high temperature side compressor 1b.
At this time, the low temperature side refrigerant evaporates in the heat source side heat exchanger 3 and condenses on the low temperature side of the intermediate heat exchanger 5. Further, the high temperature side refrigerant is condensed in the use side heat exchanger 7 and supplies hot water to the water in the use side pipe 18 which is the use side. On the high temperature side of the intermediate heat exchanger 5, the liquid refrigerant decompressed by the high temperature side expansion device 4b evaporates and absorbs the condensation heat of the low temperature side refrigerant as the evaporation heat.
In the use side pipe 18, the use side fluid fed by the feed pump 10 flows.

When the waste water temperature Tw detected by the water temperature sensor 15 is higher than the outside air temperature To detected by the outside air temperature sensor 16 provided in the heat source side heat exchanger 3, the flow path of the flow control three-way valve 14 is subjected to water heat exchange. It is switched so that drainage flows into the vessel 13. Then, both the low temperature side refrigeration cycle 6a and the high temperature side refrigeration cycle 6b are operated. Here, the high-temperature side refrigerant that could not be evaporated in the water heat exchanger 13 flows into the intermediate heat exchanger 5. In the low temperature side refrigeration cycle 6a, operation is performed at a low output in order to supply warm heat sufficient to evaporate the high temperature side refrigerant that could not be evaporated in the water heat exchanger 13.
When the temperature of the waste water flowing into the water heat exchanger 13 is sufficiently high and the high temperature side refrigerant is completely evaporated only by the water heat exchanger 13, the operation of the low temperature side refrigeration cycle 6a is stopped.

  The binary refrigeration cycle apparatus of the first and second embodiments is used as a system for supplying warm heat, for example, in factory equipment. In general factory equipment, the waste water after use may be warm water that is 10 ° C. or more higher than the outside air temperature To. This hot water is a temperature range that can be used as a heat source for the high temperature side refrigeration cycle of the binary refrigeration cycle apparatus 100, and by using the waste water temperature of such factory equipment as a heat source for the high temperature side refrigeration cycle, It is possible to stop or weaken the operation, and it is possible to supply heat with high energy efficiency. Thereby, the energy efficiency as factory equipment can be made high.

  The present invention is not limited to the above embodiment. Furthermore, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiments of the present invention. For example, you may delete some components from all the components shown by embodiment of this invention. Furthermore, you may combine the component covering different embodiment suitably.

DESCRIPTION OF SYMBOLS 1a ... Low temperature side compressor, 1b ... High temperature side compressor, 2a ... Low temperature side four way valve, 2b ... High temperature side four way valve, 3 ... Heat source side heat exchanger, 4a ... Low temperature side expansion device, 4b ... High temperature side expansion device, 5 ... Intermediate heat exchanger, 6a ... Low temperature side refrigeration cycle, 6b ... High temperature side refrigeration cycle, 7 ... Usage side heat exchanger, 8 ... Drain pump, 9 ... Drain pipe, 12a ... Intermediate heat exchanger refrigerant flow control valve, 12b ... Water heat exchanger refrigerant flow control valve, 14 ... Flow control three-way valve, 15 ... Water temperature sensor, 16 ... Outdoor air temperature sensor, 17 ... Downstream branching part, 18 ... Use side piping, 22 ... Electric component box, 23 ... Controller, 100 ... Dual refrigeration cycle device

Claims (3)

A heat source side heat exchanger that absorbs heat from an external heat source, a low temperature side refrigeration cycle including a low temperature side compressor, and a low temperature side refrigerant enclosed therein,
A high-temperature side refrigeration cycle comprising a utilization-side heat exchanger for supplying heat to the utilization side and a high-temperature side compressor, and a high-temperature-side refrigerant sealed therein
An intermediate heat exchanger for exchanging heat between the refrigerant of the low temperature side refrigeration cycle and the high temperature side refrigeration cycle;
A water heat exchanger for exchanging heat between the refrigerant of the high temperature side refrigeration cycle and water taken from the outside;
Water temperature detecting means for detecting the temperature of water taken from the outside;
An external temperature detecting means for detecting the temperature of the external heat source;
When the temperature of the water detected by the water temperature detection means is higher than the temperature of the external heat source detected by the external temperature detection means, the operation output of the low temperature side refrigeration cycle is reduced or the operation is stopped, Operation control means for controlling heat exchange between the high temperature side refrigerant and water in the water heat exchanger,
A binary refrigeration cycle apparatus comprising: The water heat exchanger is connected in parallel to the intermediate heat exchanger,
The said operation control means controls so that a refrigerant | coolant flows in into the said water heat exchanger, when the temperature detected by the said water temperature detection means is more than predetermined temperature. Original refrigeration cycle equipment. The water heat exchanger is connected in series to the intermediate heat exchanger,
The said operation control means is controlled so that water flows in into the said water heat exchanger from the outside, when the temperature detected by the said water temperature detection means is more than predetermined temperature. Dual refrigeration cycle equipment.

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