WO2006112157A1

WO2006112157A1 - Refrigeration cycle device and method of operating the same

Info

Publication number: WO2006112157A1
Application number: PCT/JP2006/303870
Authority: WO
Inventors: Tetsuya Saito; Yuuichi Yakumaru; Tomoichiro Tamura; Masaya Honma
Original assignee: Matsushita Electric Industrial Co., Ltd.
Priority date: 2005-04-14
Filing date: 2006-03-01
Publication date: 2006-10-26
Also published as: JP2008175402A

Abstract

A method of operating a refrigeration cycle device where a compressor (1), a radiator (2), an expansion device (3), and an evaporator (5) are sequentially connected to circulate a refrigerant. The radiator (2) is provided at either an outdoor unit or an indoor unit, and the evaporator (5) is provided at the other. Capacity of an outdoor fan is set lower at the time of the start of the compressor (1) for a predetermined time period than that in normal operation, and after the predetermined time period has passed, the outdoor fan is operated at a preset speed for the normal operation.

Description

Refrigeration cycle apparatus and operation method thereof

Technical field

[0001] The present invention relates to a refrigeration cycle apparatus using an expander and an operation method thereof.

Background art

[0002] In recent years, as a means for further improving the efficiency of the refrigeration cycle, an expansion machine is provided instead of the expansion valve, and in the process of expansion of the refrigerant, the pressure energy is recovered in the form of electric power or power by the expansion machine, A power recovery cycle has been proposed in which the input of the compressor is reduced by that recovery amount (see, for example, Patent Document 1).

FIG. 17 shows a conventional refrigeration cycle apparatus described in Patent Document 1. Compressors 1 are those driven by driving means (not shown) such as a traveling engine for sucking and compressing the refrigerant, the refrigerant discharged by the compressor 1 is cooled by the radiator 2. The refrigerant flowing out of the radiator 2 flows into the expander 3 to convert and recover the expansion energy of the refrigerant into mechanical energy (rotational energy), and supplies the recovered mechanical energy (rotational energy) to the generator 4. Power is generated. The refrigerant expanded under reduced pressure in the expander 3 evaporates and evaporates in the evaporator 5 and then sucked into the compressor 1 again.

[0004] Since the refrigerant is decompressed while the expansion energy is converted into mechanical energy by the expander 3, the refrigerant flowing out of the radiator 2 follows an isentropic line ( _c → d) as shown in Fig. 18. Therefore, the enthalpy is lowered while changing the phase. Therefore, the enthalpy of the evaporator 5 can be increased by the amount of expansion work Aiexp, compared to the case of simply adiabatic expansion without performing expansion work when the refrigerant is depressurized (when changing the isenthalpy). It becomes possible to increase the freezing capacity. In addition, since mechanical energy (rotational energy) can be supplied to the generator 4 by the expansion work Aiexp, the generator 4 can generate Aiexp power. By supplying the electric power to the compressor 1, it is possible to reduce the electric power necessary for driving the compressor 1, so that the COP (coefficient of performance) of the refrigeration cycle can be improved. Patent Document 1: Japanese Unexamined Patent Publication No. 2000-329416

Disclosure of the invention

Problems to be solved by the invention

[0005] However, since the expander 3 is driven by utilizing the high-low pressure difference in the refrigeration cycle, the refrigeration cycle at the time of starting up the compressor 1 is stable in the conventional configuration. Needless to say, in a state where the high / low pressure difference is not sufficiently secured, the torque required to drive the expander 3 is insufficient, and the compressor 1 continues to operate without the expander 3 being driven. At this time, since the expander 3 is stopped, the power is not recovered, and when the compressor 1 and the expander 3 are directly connected to each other by the shaft, the load on the compressor 1 is increased and the power consumption is reduced. There was a problem that it would increase. In addition, since the refrigeration cycle is closed before and after the expander 3, the low pressure of the refrigeration cycle is abnormally reduced and refrigerant is not supplied to the compressor 1, and the cooling effect of the compressor 1 by the refrigerant is reached. In the case of the scroll type compressor 1, the normal revolving motion is impaired, and the efficiency due to refrigerant leakage is reduced. There was a risk of problems such as accelerated wear.

[0006] The present invention has been made in view of the above-described problems of the prior art, and when starting up the compressor, the capacity of the expander can be quickly increased by controlling the capacity of the radiator or the evaporator. An object of the present invention is to provide a refrigeration cycle apparatus that secures a differential pressure necessary for driving, minimizes power recovery loss at the start of the compressor, and improves the reliability of the compressor, and an operation method thereof. .

Means for solving the problem

In order to achieve the above object, the present invention provides a method for operating a refrigeration cycle apparatus in which a compressor, a radiator, an expander, and an evaporator are sequentially connected to circulate a refrigerant, and the radiator is a chamber. The evaporator is provided in one of the outdoor unit and the indoor unit, and the evaporator is provided in the other of the outdoor unit and the indoor unit. When the compressor is started, the capacity of the outdoor fan is reduced for a predetermined time than during normal operation. The outdoor fan is operated at a set speed during normal operation after a predetermined time has elapsed.

[0008] Further, the present invention circulates refrigerant by sequentially connecting a compressor, a radiator, an expander, and an evaporator. The radiator is provided in one of the outdoor unit and the indoor unit, the evaporator is provided in the other of the outdoor unit and the indoor unit, and the refrigeration cycle device is provided in the outdoor unit. A controller for controlling the capacity of the fan is further provided, and when the compressor is started, the controller controls the capacity of the outdoor fan to be reduced for a predetermined time from that during normal operation. And

[0009] Alternatively, at the start of the compressor, wherein the controller the outdoor fan capacity usually controlled to be reduced from the time OPERATION, the expander inlet pressure and the differential pressure exceeds a predetermined value the outlet pressure At this point, the controller may control the outdoor fan to operate at a set speed during normal operation.

[0010] With the above configuration, it is possible to secure the differential pressure necessary for the expander to be driven quickly, so that the time until the expander is driven can be shortened.

[0011] Further, the refrigeration cycle apparatus includes a bypass circuit having an expansion valve that bypasses the expander. When the compressor is started, the refrigerant flows into the nopass circuit side, and the radiator capacity and the evaporator capacity are At least one of them is controlled so as to reduce the capacity for a predetermined time from the normal operation.

[0012] Thereby, since the refrigeration cycle is not blocked when the compressor is started, an abnormal drop in the low pressure of the refrigeration cycle can be avoided.

The invention's effect

[0013] According to the refrigeration cycle apparatus of the present invention or the operation method thereof, the differential pressure necessary for promptly driving the expander by controlling the capabilities of the radiator and the evaporator when the compressor is started up. it is possible to secure a can shorten the time until the expander is driven to minimize the power recovery loss of the compressor startup, and it is possible to improve the reliability of the compressor.

Brief Description of Drawings

FIG. 1 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram of another refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 3 is a Mollier diagram of the refrigeration cycle apparatus in Embodiment 1 of the present invention.

FIG. 4 is a flowchart of the refrigeration cycle apparatus in Embodiment 1 of the present invention. FIG. 5 is a pressure change diagram of the refrigeration cycle apparatus in Embodiment 1 of the present invention.

FIG. 6 is a configuration diagram of another refrigeration cycle apparatus according to Embodiment 1 of the present invention.

FIG. 7 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 8 is a flowchart of the refrigeration cycle apparatus according to Embodiment 2 of the present invention.

FIG. 9 is a configuration diagram of a refrigeration cycle apparatus according to a modification of the second embodiment of the present invention.

FIG. 10 is a flowchart of a refrigeration cycle apparatus in a modification of the second embodiment of the present invention.

FIG. 11 is a configuration diagram of a refrigeration cycle apparatus according to another modification of the second embodiment of the present invention.

FIG. 12 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 3 of the present invention.

FIG. 13 is a flowchart of the refrigeration cycle apparatus in Embodiment 3 of the present invention.

FIG. 14 is a configuration diagram of a refrigeration cycle apparatus according to Embodiment 4 of the present invention.

FIG. 15 is a flowchart of the refrigeration cycle apparatus in Embodiment 4 of the present invention.

FIG. 16 is a pressure change diagram of the refrigeration cycle apparatus in Embodiment 4 of the present invention.

[FIG. 17] FIG. 17 is a configuration diagram of a conventional refrigeration cycle apparatus.

[Figure 18] Figure 18 shows the Mollier diagram of a conventional refrigeration cycle system.

Explanation of symbols

1 Compressor

2, 2a, 2b radiator

3 Expander

4 Generator

5 Evaporator

6 Bypass circuit

7 Expansion valve

8 Radiator capacity controller

9 Fan for radiator

10 Evaporator capacity controller

11 Evaporator fan 12 First pressure gauge

13 Second pressure gauge

14 First thermometer

15 Second thermometer

16 Current 10

17 Primary refrigerant circuit

18 Secondary refrigerant circuit

19 Hot water storage tank

20 Circulation pump

21 User circuit

22 Hot water tap

23 Bath

24 Hot water storage tank water temperature thermometer

31 Fan controller for radiator

32 Evaporator fan controller

33 Circulation pump controller

211, 212, 213, 214, 215, 216 Controller

221, 226 timer

301, 302 On-off valve

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment 1.

As shown in FIG. 1, the refrigeration cycle apparatus of the first embodiment includes a refrigeration cycle in which a compressor 1, a radiator 2, an expander 3, and an evaporator 5 are sequentially connected to circulate refrigerant. In addition, a radiator capacity controller 8 that controls the capacity of the radiator 2 or an evaporator capacity controller 10 that controls the capacity of the evaporator 5 is provided.

[0017] The refrigeration cycle apparatus preferably also includes a generator 4 connected to the expander 3. The expander 3 recovers power by converting the expansion energy of the refrigerant into mechanical energy. The The expansion machine 3 converts the expansion energy of the refrigerant into mechanical energy (rotational energy) and recovers it, and supplies the recovered mechanical energy (rotational energy) to the generator 4 to generate electric power. The generated electric power is used, for example, as a drive source for the compressor 1. Compared to the case where the compressor 1 and the expander 3 are directly connected to each other by providing the generator 4 that generates electric power by supplying the expansion energy recovered by the expander 3, Since it is possible to reduce the load on the compressor at startup, it is possible to reduce power consumption.

Next, the radiator 2 and the radiator capacity controller 8 will be described.

[0019] The radiator 2 includes an air cooling type and a water cooling type.

The radiator capacity controller 8 is for controlling the radiator capacity, that is, the heat radiation amount of the radiator 2, and includes a cooling means for the radiator 2. Cooling means include those that exchange heat by sending air to the radiator using a radiator fan (air-cooled), and those that exchange heat using water or other fluids (such as water-cooled). In the first embodiment, the radiator 2 is an air-cooled heat exchanger, and the radiator capacity controller 8 is a radiator fan control that supplies voltage to the electric radiator fan 9 and the radiator fan 9. It consists of part 31.

[0021] One of the features of the first embodiment is that the ability of the radiator fan 9 provided in the outdoor unit during the cooling operation is reduced by the radiator fan control unit 31. By reducing the capacity of the radiator fan 9 at startup, the temperature of the radiator 2 rises quickly. Thereby, the high pressure at the inlet of the expander 3 can be increased, and the expander 3 can be driven quickly.

[0022] Generally, the heat sink capability is expressed by the following (Equation 1).

[0023] (Equation 1) Q (W) = K (W / m ² K) XA (m ² ) X ΔΤ (K)

Where Q (W): Heat sink capability

K (W / m ² K): Heat transfer rate

A (m ² ): Radiator surface area

△ T (K): (heatsink temperature-air or water temperature).

[0024] In order to drive the expander 3 quickly, the problem can be solved by quickly increasing the high-low pressure difference between the inlet and the outlet of the expander 3. This can be achieved by increasing the high pressure at the expander inlet or decreasing the low pressure at the expander outlet. [0025] In order to increase the high pressure at the expander inlet, the temperature of the radiator 2 may be increased due to the physical properties of the refrigerant. In other words, if you operate the refrigeration cycle to increase AT (K) from (Equation 1), you should decrease K (W / m ² K) or A (m ² )! In order to reduce K (W / m ² K), it is only necessary to reduce the fan air volume with an air-cooled radiator and reduce the flow rate of the water-side circulation pump with a water-cooled radiator. Further, in order to reduce A (m ² ), when a plurality of radiators 2a and 2b connected in parallel as shown in FIG. 2 are provided, the radiator used by the opening / closing operation of the on-off valves 301 and 302, for example. If you reduce the quantity,

Next, the evaporator 5 and the evaporator capacity controller 10 will be described.

The evaporator capacity controller 10 is for controlling the amount of heat absorbed by the evaporator 5, and includes heating means for the evaporator 5. In Embodiment 1, the evaporator 5 is also an air-cooled heat exchanger. The evaporator capacity controller 10 includes an electric evaporator fan 11 and an evaporator fan controller 32 that supplies voltage to the evaporator fan 11. Heat exchange with air and evaporator 5.

[0028] Another feature of the first embodiment is that the ability of the evaporator fan 11 provided in the outdoor unit during the heating operation is reduced by the evaporator fan control unit 32. In order to shorten the time until the tension machine 3 is driven, it is necessary to quickly ensure the high-low pressure difference at the inlet / outlet of the expander 3. One method for this is to quickly reduce the low pressure at the outlet of the expander 3, that is, to quickly reduce the temperature of the evaporator 5. By reducing the capacity of the evaporator fan 11 when the compressor 1 starts up, the temperature of the evaporator 5 quickly decreases. Thereby, the low pressure at the outlet of the expander 3 can be reduced, and the expander 3 can be driven quickly.

[0029] As shown in FIG. 1, the refrigeration cycle apparatus of Embodiment 1 desirably further includes a bypass circuit 6 that bypasses the expander 3, and an expansion valve 7 as a decompression means in the bypass circuit 6. Have When the compressor 1 is started, the refrigerant flows into the bypass circuit 6 side, and at least one of the heat sink fan 9 and the evaporator fan 11 has a capacity for a predetermined time (for example, 3 minutes or more) during normal operation. It is desirable to control to reduce. This prevents the refrigeration cycle from being blocked when the compressor 1 is started, so it is possible to avoid an abnormal drop in the low pressure of the refrigeration cycle, improving the reliability of the compressor 1 and starting the compressor 1. At the same time, the power recovery loss of the expander 3 can be reduced.

[0030] Further, the refrigeration cycle apparatus of the first embodiment includes a controller (control) that controls the start and stop of the compressor 1, the opening of the expansion valve 7, the radiator capacity controller 8, and the evaporator capacity controller 10. Instrument) 211. The controller 211 includes a timer 221. The timer 221 may be provided in connection with the controller 211 outside the force controller 211 provided in the controller 211 in FIG. As will be described later, it is possible to construct a simple and low-cost system by shifting from the control of the refrigeration cycle apparatus when the compressor 1 is started to the control during normal operation by the timer 222.

Next, the change in the energy state of the refrigerant during the normal operation of the refrigeration cycle apparatus configured as described above will be described with reference to the Mollier diagram shown in FIG. 3, taking a home air conditioner as an example. To do.

[0032] The low-temperature and low-pressure refrigerant is compressed by the operation of the compressor 1, becomes a high-temperature and high-pressure refrigerant, and is discharged (A → B).

[0033] The discharged refrigerant exchanges heat with the outdoor air during the cooling operation and indoor air during the heating operation and flows into the expander 3 by the action of the radiator fan 9 in the radiator 2 (B → C).

[0034] Isentropic expansion is performed in the expander 3, the pressure is reduced while generating mechanical energy, and the vapor reaches the evaporator 5. At this time, the expansion valve 7 is fully closed by the controller 211 (C → D).

[0035] Due to the action of the evaporator fan 11 in the evaporator 5, the refrigerant exchanged heat with the indoor air during the cooling operation and with the outdoor air during the heating operation becomes a gaseous state, and then passes through a suction pipe (not shown). Sucked into compressor 1 (D → A).

[0036] As a result, when the radiator 2 is used as a heating source for a heater, a vending machine, etc., the coefficient of performance COP = (IB -iC) / ((iB-iA)-(iE— iD)), reducing the required power of the compressor 1 compared to a refrigeration cycle system that is enthalpy-expanded with a conventional expansion valve, a capillary tube, etc. Can improve efficiency.

[0037] When the evaporator 5 is used as a cooling source for an air conditioner, a home refrigerator, a commercial refrigerator, an ice maker, a vending machine, etc., the electric power generated by the generator 4 is used as a drive source for the compressor 1. As interest The coefficient of performance COP = ((iA—iE) + (iE-iD)) / ((iB-iA) one (iE— iD)), and so on with conventional expansion valves, cylindrical tubes, etc. Compared with the refrigeration cycle device that expands by enthalpy, the required power of the compressor 1 is reduced and the refrigeration effect is increased, so that the efficiency is further improved.

[0038] Next, an operation method of the refrigeration cycle apparatus of the first embodiment will be described with reference to the flowchart of FIG. Here, the case where it is used as a heater will be described as an example.

[0039] In the case of a heater, when an indoor temperature detection means (not shown) detects a temperature lower than a set temperature, the controller (controller) 211 starts the compressor 1 and starts the accumulated power S of the timer 221 and starts it. Go to step 100. At start-up step 100, controller 211 sends a signal to radiator capacity controller 8 and evaporator capacity controller 10 to stop radiator fan 9 and evaporator fan 11 (or keep it stopped). Then, control the throttle opening of the expansion valve 7 appropriately, and proceed to Step 110. At this time, the expansion energy is not recovered by the expander 3 (the expander 3 is in a stopped state), and the refrigerating cycle operation in which the expansion valve 7 performs isenthalpy expansion is performed.

[0040] In step 110, the integrated value TA of the timer 221 is compared with a preset set time TX1. If the accumulated value TA of timer 221 is smaller than the set time TX1, return to start step 100 to avoid blockage of the freezing cycle, and start step 100 until the accumulated value TA of timer 221 reaches the set time TX1 or more. Maintain the operating state of. If the accumulated value TA of timer 22 1 is equal to or greater than the set time TX1, the operation proceeds to normal operation step 120, and a signal is sent from the controller 211 to the radiator capacity controller 8 and the evaporator capacity controller 10, and the fan for the radiator 9 In addition, the evaporator fan 11 is operated at a set speed suitable for normal operation, the expansion valve 7 is fully closed, the capacity of the radiator 2 and the evaporator 5 is maximized, and the refrigerant is applied only to the expander 3 side. To recover the expansion energy. At this time, the integrated value TA of the timer 221 is reset.

[0041] When the normal operation step 120 is continued, for example, when an indoor temperature detection means (not shown) detects a set temperature or higher, the routine proceeds to step 130, where the controller 211 controls the compressor 1, the radiator fan 9, and the evaporator fan. 11 stops.

[0042] Although the case of the heater has been described above, the same applies to the case of the air conditioner. In FIG. 5, the pressure change at the inlet / outlet of the expander 3 is shown by a solid line, and the differential pressure at the inlet / outlet of the expander 3 is shown by a broken line when the compressor 1 is activated. Before the compressor 1 is started, the pressure at the inlet / outlet of the expander 3 is in a balanced state, so the differential pressure is almost OMPa.

[0044] When the compressor 1 is started, the radiator fan 9 and the evaporator fan 11 are stopped. Therefore, the temperature of the radiator 2 rises quickly, and the temperature of the evaporator 5 falls quickly. As a result, the inlet pressure PG of the expander 3 rises quickly, and the outlet pressure PE of the expander 3 falls quickly. In addition, the differential pressure at the inlet / outlet of the expander 3 quickly increases, and when the differential pressure A (PG — PE) reaches the starting torque of the expander 3, that is, ΔΡΧ that is the starting differential pressure, for example, the expander 3 becomes the scroll expander. In this case, the movable scroll (not shown) starts rotating, and the refrigerant is decompressed and expanded, and the expansion energy is recovered. Therefore, experimentally determining the relationship between the accumulated time (set time TX1) from when the compressor 1 is started and the differential pressure ΔΡΧ required to drive the expander 3 is shown in the flowchart of FIG. As shown in the figure, the routine proceeds from step 110 to the normal operation step 120, and at the same time the expander 3 is driven, the controller 211 operates the radiator fan 9 and the evaporator fan 11 and fully closes the expansion valve 7 to dissipate heat. It is possible to increase the capacity of the evaporator 2 and the evaporator 5.

[0045] Further, when the compressor 1 is started, control is performed so that the refrigerant passes through the bypass circuit 6 side, and a sufficient differential pressure at the inlet / outlet of the expander 3 is secured to supply the refrigerant to the force expander 3 side. By starting the operation, the refrigeration cycle is not blocked, so that an abnormal drop in the low pressure of the refrigeration cycle can be avoided and the reliability of the compressor 1 can be improved.

Note that the refrigeration cycle apparatus of the first embodiment is configured to include the bypass circuit 6 that bypasses the expander 3, but as shown in FIG. 6, the bypass circuit 6 that bypasses the expander 3. Even when the compressor 1 is started, the radiator fan 9 or the evaporator fan 11 1 is stopped when the compressor 1 is started, so that the expander can be operated more quickly than when the radiator fan 9 or the evaporator fan 11 is normally operated. 3 can be driven.

[0047] Further, when the compressor 1 is started, the radiator fan 9 and the evaporator fan 11 are stopped. The applied voltage to each fan is smaller than that during normal operation, and the radiator 2 and By reducing the amount of air passing through the evaporator 5, it is possible to prevent an excessive increase in the compression ratio, so that the reliability of the compressor 1 can be ensured while the expander 3 is driven quickly to operate. Power recovery loss can be reduced.

[0048] In the above description, the case where the radiator fan 9 and the evaporator fan 11 are stopped or decelerated when the compressor 1 is started has been described. However, the gist of the present invention is that when the compressor is started in the air conditioner or the like. In other words, the radiator fan provided in the outdoor unit is stopped or decelerated, or the evaporator fan provided in the outdoor unit is stopped or decelerated when starting the compressor in a heater or the like. For example, when the compressor is started, the outdoor fan is particularly stopped or decelerated.

[0049] Although the above-described first embodiment has been described by taking the heater or the air conditioner of Fig. 1 as an example, the present invention is naturally applicable to an air conditioner including a four-way valve for switching the refrigerant flow. The same applies to the embodiments described below.

[0050] It should be noted that when both the outdoor fan and the indoor fan are stopped at the time of starting the compressor, it is obvious that the effect is large. When only one of them is stopped, or when only one of the airflows is reduced, etc. In both cases, the expander 3 can be driven more quickly than in the case of normal operation. In addition, even in a refrigeration cycle apparatus (see, for example, Embodiment 4 to be described later) having only one of the radiator fan 9 or the evaporator fan 11, the effect of the present invention can be obtained by stopping the fan or reducing the air volume. It is done.

[0051] Embodiment 2.

As shown in FIG. 7, the refrigeration cycle apparatus of Embodiment 2 includes a first pressure gauge 12 that detects the inlet pressure of the expander 3 in addition to the refrigeration cycle apparatus shown in FIG. A second pressure gauge 13 for detecting the outlet pressure of the expander 3 is arranged in the outlet pipe of the expander 3 on the side pipe, and the signals from the first pressure gauge 12 and the second pressure gauge 13 are And a controller (controller) 212 for controlling the opening degree of the expansion valve 7, the radiator capacity controller 8, and the evaporator capacity controller 10.

[0052] The operation method of the refrigeration cycle apparatus of the second embodiment is performed by the timer in the first embodiment! /, And the start step force also shifts to the normal operation step. This is a control method in which the difference between the pressure detected by the second pressure gauge 13 and the second pressure gauge 13 exceeds a set value. By such an operation method, it is possible to most accurately determine the force with which an appropriate differential pressure is secured to drive the expander 3, and the power recovery is started more reliably by the expander 3. At the same time, it is possible to promptly shift to a normal operation state in which the capabilities of the radiator 2 and the evaporator 5 are increased.

[0053] As shown in FIG. 7, the arrangement position of the first pressure gauge 12 is most suitable on the inlet side of the expander 3, but from the discharge side of the compressor 1 of the refrigeration cycle to the outlet of the radiator 2. The same role can be played everywhere. As shown in FIG. 7, the piping on the outlet side of the expander 3 is most appropriate as the position of the second pressure gauge 13, but from the outlet side of the expander 3 of the refrigeration cycle, the compressor 1 If the suction side, can play the same role

Next, the operation method of the refrigeration cycle apparatus of the second embodiment will be described in detail based on the flow chart of FIG.

[0055] For example, in the case of a heater, when an indoor temperature detection means (not shown) detects a temperature equal to or lower than a set temperature, the compressor 212 is started by the controller 212, and the start step 200 is performed. At the start step 200 0, a signal is sent from the controller 212 to the radiator capacity controller 8 and the evaporator capacity controller 10 to stop the heat radiator fan 9 and the evaporator fan 11 (or continue the stopped state). At the same time, the throttle opening degree of the expansion valve 7 is appropriately controlled, and the routine proceeds to step 210. At this time, expansion energy is not collected by the expander 3 (the expander 3 is in a stopped state), and the refrigeration cycle operation in which the expansion valve 7 performs isenthalpy expansion is performed.

[0056] In step 210, the controller 212 calculates a difference A (PG-PE) between the detected value PG (inlet pressure) of the first pressure gauge 12 and the detected value PE (outlet pressure) of the second pressure gauge 13. While calculating, the difference Δ (PG-PE) is compared with the preset differential pressure value ΔΡΧ. If the difference △ (PG-PE) is smaller than the differential pressure value ΔΡΧ, the operation returns to the start step 200, and the operation state of the start step 200 is maintained until the difference A (PG-PE) exceeds the differential pressure value △ PX. . When the difference A (PG—PE) exceeds the differential pressure value ΔΡΧ, the operation proceeds to the normal operation step 220, and the controller 212 sends a signal to the radiator capacity controller 8 and the evaporator capacity controller 10, and the radiator fan 9 And the evaporator fan 11 and the expansion valve 7 are fully closed, the capacity of the radiator 2 and the evaporator 5 is increased, and the refrigerant is supplied only to the expander 3 side to recover the expansion energy. It becomes a state.

[0057] Next, when an indoor temperature detection means (not shown) detects a set temperature or higher, step 230 is performed. The controller 212 stops the compressor 1, the radiator fan 9, and the evaporator fan 11 by the controller 212.

[0058] Thus, by detecting the pressure at the inlet / outlet of the expander 3, it is possible to most accurately determine whether or not an appropriate differential pressure is secured for driving the expander 3. The power recovery by the expander 3 is surely started, and at the same time, it is possible to promptly shift to the normal operation state in which the capacity of the radiator 2 and the evaporator 5 is increased. As a result, it is possible to bypass the expander 3 when the compressor 1 starts up and to minimize the time during which the radiator fan 9 and the evaporator fan 11 are stopped. It can be minimized.

FIG. 9 shows a refrigeration cycle apparatus as a modified example of the above-described second embodiment. Instead of the second pressure gauge 13, a first thermometer 14 that detects the temperature of the evaporator 5 is shown. (For example, a thermistor). By moving from the startup step of the compressor 1 to the normal operation step based on the pressure value detected by the first pressure gauge 12 and the temperature detected by the first thermometer 14, accurate and low-cost The step transition can be realized.

[0060] The first thermometer 14 is in a position where the temperature of the evaporator 5 can be detected. Specifically, the outlet force of the expander 3 may be installed in a pipe leading to the outlet of the evaporator 5.

More preferably, the refrigeration cycle apparatus includes a controller (controller) 213 for controlling the opening degree of the radiator capacity controller 8, the evaporator capacity controller 10, and the expansion valve 7, as shown in FIG. It has. The controller 213 is provided with expander outlet pressure calculating means for calculating the physical force saturation pressure of the refrigerant used, that is, the pressure on the outlet side of the expander 3, based on the temperature detected by the first thermometer 14. Speak.

[0062] A control method at the time of starting the compressor 1 of the refrigeration cycle apparatus configured as described above will be described based on the flowchart of FIG.

For example, in the case of a heater, when an indoor temperature detection means (not shown) detects a temperature equal to or lower than a set temperature, the controller (controller) 213 starts up the compressor 1 and proceeds to the start step 300. In starting step 300, signals are sent from the controller 213 to the radiator capacity controller 8 and the evaporator capacity controller 10 to stop the radiator fan 9 and the evaporator fan 11 and to stop the expansion valve 7 Adjust the opening appropriately, and go to Step 310. The controller 213 is equipped with The detected value force of the first thermometer 14 and the outlet pressure PE ′ of the expander 3 are always calculated by the expanded expander outlet pressure calculation means. At this time, the expansion energy is not recovered by the expander 3 (the expander 3 is in a stopped state), and the refrigerating cycle operation in which the expansion valve 7 performs isenthalpy expansion is performed.

[0064] In step 310, the controller 213 determines the difference A between the detected value PG (inlet pressure) of the first pressure gauge 12 and the outlet pressure PE 'of the expander 3 that also estimates the detected value force of the first thermometer 14. (PG−PE ′) is calculated and the difference Δ (PG−PE ′) is compared with a preset differential pressure value ΔΡΧ. If the difference A (PG—ΡΕ ′) is smaller than the differential pressure value ΔΡΧ, the process returns to the start step 300, and the operating state of the start step 300 is changed until the differential Δ (PG—PE ′) becomes greater than the differential pressure value ΔΡΧ. maintain. If the difference A (PG-PE ') is greater than the differential pressure value ΔΡΧ, the operation proceeds to the normal operation step 320, and the controller 213 sends a signal to the radiator capacity controller 8 and the evaporator capacity controller 10 for the radiator. Operate fan 9 and evaporator fan 11 and fully expand expansion valve 7 to increase the capacity of radiator 2 and evaporator 5 and supply refrigerant only to expander 3 side to recover expansion energy. It becomes a driving state.

Next, when an indoor temperature detection means (not shown) detects a set temperature or higher, the routine proceeds to step 330, where the controller 1, the compressor 1, the radiator fan 9, and the evaporator fan 11 are stopped by the controller 213.

[0066] As a result, whether or not the differential pressure appropriate for driving the expander 3 is ensured is more accurate than when the second pressure gauge 13 detects the outlet pressure of the expander 3. It is possible to estimate at low cost.

[0067] Since the pressure difference at the inlet / outlet of the expander 3 is highly dependent on the pressure on the inlet side of the expander 3! /, The expander 3 is driven only by the detected value of the first pressure gauge 12. It is also possible to roughly estimate the force force that ensures a proper differential pressure. In this case, it is not necessary to provide the second pressure gauge 13 or the first thermometer 14, so that it is possible to provide a more inexpensive refrigeration cycle.

FIG. 11 shows a refrigeration cycle apparatus as another modification of the above-described second embodiment, and a pipe extending from the discharge side of the compressor 1 to the inlet of the radiator 2 without using a pressure gauge. This is a configuration using a second thermometer 15 that detects the temperature. Inlet machine 3 inlet pressure and compressor 1 The discharge side force of the radiator has a correlation with the temperature of the pipe leading to the inlet of the radiator 2, so by measuring the discharge temperature of the compressor 1, the inlet pressure of the expander 3 is estimated, and based on this inlet pressure Therefore, the differential pressure across the expander 3 can be estimated.

[0069] In this modification, when the second thermometer 15 detects a set temperature or higher, a signal is sent from the controller (controller) 214 to the radiator capacity controller 8 and the evaporator capacity controller 10 to dissipate heat. The fan 9 and the evaporator fan 11 are operated and the expansion valve 7 is fully closed, the capacity of the radiator 2 and the evaporator 5 is increased, and the refrigerant is supplied only to the expander 3 side to recover the expansion energy. The transition to the normal operation state can be realized at a lower cost.

[0070] Embodiment 3.

FIG. 12 shows a schematic diagram of the refrigeration cycle apparatus in the third embodiment. The same components as those in the first embodiment are given the same reference numerals.

In FIG. 12, the refrigeration cycle apparatus of the third embodiment is provided with an ammeter 16 for detecting the current flowing through the generator 4, and the opening of the expansion valve 7, the heat dissipation by the signal of the ammeter 16. A controller (controller) 215 for controlling the vessel capacity controller 8 and the evaporator capacity controller 10 is provided.

A control method at the time of starting the compressor 1 of the refrigeration cycle apparatus configured as described above will be described based on the flowchart of FIG.

[0073] For example, in the case of a heater, when an indoor temperature detection means (not shown) detects a temperature equal to or lower than a set temperature, the compressor 1 is activated by the controller 215, and the activation step 400 is performed. At start-up step 400, a signal is sent from the controller 215 to the radiator capacity controller 8 and the evaporator capacity controller 10 to stop the heat radiator fan 9 and the evaporator fan 11 and to open the throttle valve 7 Is appropriately controlled, and the process proceeds to Step 410. At this time, the expansion energy is not recovered by the expander 3 (the expander 3 is in a stopped state), and the refrigeration cycle operation in which the expansion valve 7 performs isenthalpy expansion.

In step 410, the controller 215 detects the current value A 1 flowing through the generator 4 from the ammeter 16, and proceeds to step 420. In step 420, the current value A1 flowing through the generator 4 is compared with a preset current value AX (eg, 0 amperes). The current value A1 flowing through the generator 4 is If it is smaller than the preset current value AX, it is determined that the generator 4 has not started generating power, that is, the expander 3 is not driven, and the current value A1 flowing through the generator 4 is preset. The start step 400 is maintained until the current value exceeds AX. When the current value A1 flowing through the generator 4 is greater than or equal to the preset current value AX, it is determined that the generator 4 has started generating power, that is, the expander 3 is operating, and the normal operation step 430 Then, a signal is sent from the controller 215 to the radiator capacity controller 8 and the evaporator capacity controller 10 to operate the radiator fan 9 and the evaporator fan 11, and the expansion valve 7 is fully closed. In addition, the capacity of the evaporator 5 is increased, and the refrigerant is supplied only to the expander 3 side to recover the expansion energy.

[0075] Next, when an indoor temperature detection means (not shown) detects a set temperature or higher, the process proceeds to step 440, and the compressor 1, the radiator fan 9, and the evaporator fan 11 are stopped by the controller 215.

Thus, by detecting the current value of the generator 4, it is possible to accurately grasp that the expander 3 has been driven, and at the same time that the power recovery is started by the expander 3, the radiator 2 and the evaporator 2 are evaporated. Since it is possible to quickly shift to the normal operation state in which the capacity of the compressor 5 is increased, the power recovery loss of the expander 3 when the compressor 1 is started can be minimized.

[0077] Embodiment 4.

FIG. 14 shows a schematic diagram of the refrigeration cycle apparatus in the fourth embodiment. The same components as those in Embodiments 1 to 3 are denoted by the same reference numerals.

In FIG. 14, the refrigeration cycle apparatus of the fourth embodiment includes a primary side refrigerant circuit 17 and a secondary side refrigerant circuit 18. The primary refrigerant circuit 17 includes a compressor 1, a water-cooled radiator 2 having, for example, a double pipe specification, an expander 3 that recovers power by converting expansion energy of the refrigerant into mechanical energy, and an evaporator 5 Are sequentially connected in series, and a bypass circuit 6 for bypassing the expander 3 is provided, and an expansion valve 7 is provided in the bypass circuit 6 as a pressure reducing means. The secondary refrigerant circuit 18 includes a hot water storage tank 19, a radiator 2, and a circulation pump 20 for circulating water. The radiator capacity controller 8 includes a circulation pump 20 and a circulation pump control unit 33 that supplies voltage to the circulation pump 20. The amount of water flowing through the secondary refrigerant circuit 18 is variable by the action of the circulation pump 20. Especially This makes it possible to control the capacity of radiator 2. The radiator 2 is configured such that the refrigerant flows in the primary side refrigerant circuit 17 and the secondary side refrigerant circuit 18 are opposed to each other. In addition, the hot water storage tank 19 is configured to supply tap water from the lower part and supply hot water that has become hot due to the action of the radiator 2 from the upper part to the use side circuit 21. Is supplied to the bath tub 23 through the hot-water tap 22 for use. The hot water storage tank 19 is provided with a hot water storage tank water temperature thermometer 24 (for example, a thermistor) that detects the water temperature in the hot water storage tank 19. A controller (controller) 216 having a built-in timer 226 for controlling the start and stop, as well as the opening degree of the expansion valve 7, the radiator capacity controller 8, and the evaporator capacity controller 10 is provided.

[0079] A control method at the time of starting the compressor 1 of the refrigeration cycle apparatus configured as described above will be described with reference to the flowchart of FIG.

[0080] In step 500, when the hot water tank water temperature TB (° C) detected by the hot water tank water temperature thermometer 24 detects that the temperature is lower than the set temperature TL (° C), the process proceeds to step 510, and the controller 216 At the same time, timer 226 integration starts. In start-up step 520, a signal is sent from the controller 216 to the radiator capacity controller 8 and the evaporator capacity controller 10, and the circulation pump 20 and the evaporator fan 11 are stopped (or kept stopped), and the expansion valve Adjust the throttle opening of 7 as appropriate, and go to Step 530. At this time, the expansion energy is not recovered by the expander 3 (the expander 3 is in a stopped state), and the refrigeration cycle operation in which the expansion valve 7 performs isenthalpy expansion is performed.

[0081] In step 530, the integrated value TA of timer 226 is compared with preset time TX2. In step 530, until the accumulated value TA of the timer 226 exceeds the set time TX2, the process returns to the start step 520, and the operation state of the start step 520 is maintained until the accumulated value TA of the timer 226 becomes larger than the set time TX2. When the accumulated value TA of timer 226 becomes larger than the set time TX2, the routine proceeds to normal operation step 540, and a signal is sent from the controller 216 to the radiator capacity controller 8 and the evaporator capacity controller 10, and the circulation pump 20 and Normal operation in which the evaporator fan 11 is operated and the expansion valve 7 is fully closed to increase the capacity of the radiator 2 and the evaporator 5 and the refrigerant is supplied only to the expander 3 side to recover the expansion energy. It becomes a state. At this time, the integrated value TA of the timer 226 is reset. [0082] Next, when the hot water storage tank water temperature TB (° C) detected by the hot water storage tank water temperature thermometer 24 in step 550 detects the set temperature TH (° C) or more, the process proceeds to step 560 and the controller 216 The compressor 1, the circulation pump 20, and the evaporator fan 11 are stopped.

In FIG. 16, the pressure change at the inlet / outlet of the expander 3 when the compressor 1 is activated is indicated by a solid line, and the differential pressure at the inlet / outlet of the expander 3 is indicated by a broken line. Before the compressor 1 is started, the pressure at the inlet / outlet of the expander 3 is in a balanced state, so the differential pressure is almost OMPa.

[0084] When the compressor 1 is started, the circulation pump 20 and the evaporator fan 11 are stopped. Therefore, the temperature of the radiator 2 rises quickly, and the temperature of the evaporator 5 falls quickly, and the result As a result, the inlet pressure PG of the expander 3 quickly increases, and the outlet pressure PE of the expander 3 quickly decreases. In addition, the differential pressure at the inlet / outlet of the expander 3 quickly increases, and when the differential pressure A (PG-PE) reaches the starting torque of the expander 3, that is, ΔΡΧ which is the starting differential pressure, for example, the expander 3 becomes the scroll expander. In this case, the movable scroll (not shown) starts to rotate, decompressing and expanding the refrigerant, and recovering the expansion energy. Therefore, when the relationship between the accumulated time (set time TX2) after the compressor 1 is started and the differential pressure ΔΡΧ required to drive the expander 3 is experimentally determined, it is shown in the flowchart of FIG. Thus, the operation proceeds from step 530 to the normal operation step 540, and at the same time the expander 3 is driven, the controller 216 operates the circulation pump 20 and the evaporator fan 11 and the expansion valve 7 is fully closed, and the radiator 2 And the capacity of the evaporator 5 can be increased.

[0085] As in the first embodiment, the configuration includes the bypass circuit 6 that bypasses the expander 3. However, the compressor 1 can be started even when the bypass circuit 6 that bypasses the expander 3 is not provided. By stopping the circulation pump 20 or the evaporator fan 11 during operation, the expander 3 can be driven quickly.

[0086] Further, the force that is supposed to stop the circulation pump 20 when the compressor 1 is started. The applied voltage to the circulation pump 20 is made smaller than that during normal operation, and the secondary refrigerant flows into the radiator 2 more than during normal operation. By reducing the amount of water in the circuit 18, an excessive increase in the compression ratio can be prevented, so that the reliability of the compressor 1 can be secured and the power recovery port can be reduced by driving the expander 3 quickly. Is possible.

[0087] As described above, as in the first to third embodiments, a freezing cycle using hot water such as a water heater. Since the high pressure in the refrigeration cycle can also be quickly increased in the air flow device, the differential pressure necessary for driving the expander 3 can be quickly secured, and the time until the expander 3 is driven. Therefore, the power recovery port of the expander 3 when the compressor 1 is started can be reduced.

[0088] In Embodiments 1 to 4, it is desirable to use carbon dioxide as the refrigerant.

Necessary to rotate the expander 3 because the difference between the high and low pressures at the inlet and outlet of the expander 3 in the refrigeration cycle is increased by using carbon dioxide as the refrigerant and operating with the high pressure side in the supercritical state. Pressure difference (torque) can be obtained more quickly, and the time to stop the radiator fan 9 and the evaporator fan 11 when the compressor 1 is started can be shortened. It can be minimized.

Industrial applicability

As described above, in the refrigeration cycle apparatus according to the present invention, at the time of starting up the compressor, at least one of the cooling means of the radiator 2 and the heating means of the evaporator 5 is maintained for a predetermined time during normal operation. By controlling to reduce the capacity, it is possible to reduce the power recovery loss of the expander at the time of starting the compressor, so hot water heaters, air conditioning and air conditioning equipment, vending machines, household refrigerators, commercial use It can be applied to a wide range of equipment such as refrigerators and ice makers.

Claims

The scope of the claims

[1] A method for operating a refrigeration cycle apparatus in which a refrigerant, a radiator, an expander, and an evaporator are connected in order to circulate refrigerant.

The radiator is provided in one of the outdoor unit and the indoor unit, and the evaporator is provided in the other of the outdoor unit and the indoor unit,

A method of operating a refrigeration cycle apparatus in which the capacity of an outdoor fan is reduced for a predetermined time during normal operation when the compressor is started, and the outdoor fan is operated at a set speed during normal operation after a predetermined time has elapsed. .

[2] The outdoor fan is provided in the radiator, and when the compressor is started in a cooling operation, the capacity of the radiator is reduced by reducing the air volume by the outdoor fan from the air volume in the normal operation for the predetermined time. 2. The method of operating a refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is reduced.

[3] The outdoor fan is provided in the evaporator, and the capacity of the evaporator is reduced by reducing the amount of air from the outdoor fan during the predetermined time for a predetermined time during startup of the compressor in heating operation. 2. The method of operating a refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is reduced.

4. The operation method of the refrigeration cycle apparatus according to claim 1, wherein when the compressor is started, the refrigerant is caused to flow into a bypass circuit that bypasses the expander.

[5] The refrigeration cycle apparatus according to claim 1, wherein the predetermined time is a time from when the compressor is started until a differential pressure between an inlet pressure and an outlet pressure of the expander becomes a predetermined value or more. how to drive.

[6] A refrigeration cycle device for circulating a refrigerant by sequentially connecting a compressor, a radiator, an expander, and an evaporator,

The refrigeration cycle apparatus further includes a controller that controls the capacity of the outdoor fan, and when the compressor is started, the controller controls the capacity of the outdoor fan to be reduced for a predetermined time from that during normal operation. Refrigeration cycle equipment.

[7] The outdoor fan is provided in the radiator, and the controller reduces the air volume of the outdoor fan from the air volume during normal operation for the predetermined time when the compressor is started in cooling operation. The refrigeration cycle apparatus according to claim 6, wherein the refrigeration cycle apparatus is controlled to reduce the capacity of the radiator.

[8] The outdoor fan is provided in the evaporator, and the controller reduces the air volume of the outdoor fan from the air volume during normal operation for the predetermined time when the compressor is started in heating operation. The refrigeration cycle apparatus according to claim 6, wherein the refrigeration cycle apparatus is controlled to reduce the capacity of the evaporator.

[9] The refrigeration cycle device according to claim 6, further comprising a bypass circuit including an expansion valve that bypasses the expander, wherein a refrigerant is caused to flow into the bypass circuit when the compressor is started.

[10] The system according to claim 6, further comprising a timer, wherein when the compressor is started, the timer is started after the compressor is started, and when the timer reaches a set time, the normal operation is started. The refrigeration cycle apparatus described in 1.

11. The refrigeration cycle apparatus according to claim 6, further comprising a generator that generates electric power when supplied with expansion energy recovered by the expander.

[12] The method according to claim 11, further comprising an ammeter that detects a current flowing through the generator, wherein when the ammeter detects a set value or more after the compressor is started, the operation is shifted to a normal operation. Refrigeration cycle equipment.

13. The refrigeration cycle apparatus according to claim 6, wherein the radiator is a water-cooled radiator.

[14] The controller includes an electric circulation pump and a control unit for driving the circulation pump. When the compressor is started, the amount of water exchanged with the radiator is determined for the predetermined time.

14. The refrigeration cycle apparatus according to claim 13, wherein the refrigeration cycle apparatus is configured to reduce the amount of water during normal operation.

15. The refrigeration cycle apparatus according to claim 6, wherein the refrigerant is carbon dioxide.

[16] A refrigeration cycle device for circulating a refrigerant by sequentially connecting a compressor, a radiator, an expander, and an evaporator,

The radiator is provided in one of the outdoor unit and the indoor unit, and the evaporator is provided in the other of the outdoor unit and the indoor unit, The refrigeration cycle apparatus further includes a controller that controls the capacity of the outdoor fan, and when the compressor is started, the controller controls the capacity of the outdoor fan to be lower than that during normal operation, and the expansion The refrigeration cycle apparatus that controls the controller to operate the outdoor fan at a set speed during normal operation when a differential pressure between the inlet pressure and the outlet pressure of the machine becomes a predetermined value or more.

[17] A pressure gauge disposed in a pipe from the discharge side of the compressor to the outlet of the radiator is further provided, and the differential pressure is estimated from a detected value of the pressure gauge after the compressor is started. The refrigeration cycle apparatus according to claim 16, wherein the refrigeration cycle apparatus is configured as described above.

[18] A first pressure gauge disposed in a pipe extending from the discharge side of the compressor to an outlet of the radiator, and an outlet force of the expander disposed in a pipe extending to the suction side of the compressor 17. The apparatus according to claim 16, further comprising a second pressure gauge, wherein the differential pressure is detected by a pressure value detected by the first pressure gauge and the second pressure gauge after the compressor is started. The refrigeration cycle apparatus described in 1.

[19] A pressure gauge disposed in a pipe from the discharge side of the compressor to the outlet of the radiator, and a thermometer disposed in a pipe from the outlet of the expander to the outlet of the evaporator; The differential pressure is detected by the pressure value detected by the pressure gauge and the pressure value calculated based on the temperature detected by the thermometer after the compressor is started. The refrigeration cycle apparatus according to claim 16.

[20] The apparatus further includes a thermometer that detects a temperature of a pipe from the discharge side of the compressor to an inlet of the radiator, and the differential pressure based on the temperature detected by the thermometer after the compressor is started. The refrigeration cycle apparatus according to claim 16, wherein the refrigeration cycle apparatus is estimated.

21. The refrigeration cycle apparatus according to claim 16, further comprising a generator that generates electric power when supplied with expansion energy recovered by the expander.

22. The refrigeration cycle apparatus according to claim 16, wherein the radiator is a water-cooled radiator.

[23] The controller is composed of an electric circulation pump and a control unit for driving the circulation pump, and at the time of starting the compressor, the amount of water to be exchanged with the radiator during the predetermined time, 23. The refrigeration cycle apparatus according to claim 22, wherein the refrigeration cycle apparatus reduces the amount of water during normal operation.

24. The refrigeration cycle apparatus according to claim 16, wherein the refrigerant is carbon dioxide.