JPH05157297A - Heat accumulating type cooling device - Google Patents

Abstract

PURPOSE:To permit effective room cooling by inexpensive midnight electric charge by a method wherein the amount of accumulated heat, accumulated in heat accumulating medium by heat accumulating operation in a midnight power time band, is utilized for cooling operation in daytime. CONSTITUTION:Upon heat accumulating operation in a midnight power time band, opening and closing devices 10-12 are closed and opening and closing devices 13-16, 20 are opened and a compressor 1 is operated while stopping a refrigerant gas pump 18 as it is. High-temperature high-pressure gas from the compressor 1 is condensed and liquefied in a condenser 2, expanded aditabatically in a first pressure reducing mechanism 3, changed into two-phase fluid of liquid and gas of a low temperature, enters a heat accumulating heat exchanger 8, deprives the accumulating medium 6 of heat, evaporated and gassified, then, is returned into the compressor 1. Upon utilizing the accumulated heat for the cooling operation in daytime, heat is supplied from a heat accumulating tank 7 into an evaporator 4 by a refrigerant gas pump 18 through the heat accumulating heat exchanger 8 and the second pressure reducing mechanism 19. According to this method, cooling can be effected effectively by inexpensive midnight electric charge.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat storage type cooling device.

[0002]

2. Description of the Related Art In a heat storage type cooling device as disclosed in, for example, Japanese Patent Application Laid-Open No. 1-174864, the ratio of heat storage to the total cooling load during air conditioning operation time is about 20% throughout the air conditioning operation time, and the heat storage dependence rate is There was a problem that it was relatively small.

That is, FIG. 15 shows a conventional embodiment,
The compressor 1, the condenser 2, the first pressure reducing mechanism 3 for reducing the pressure of the refrigerant, the evaporator 4 and the accumulator 5 are connected to the main refrigerant circuit 2
A heat storage tank 7 which is connected by 4 and contains a medium capable of storing heat is arranged. Further, inside the heat storage tank 7, a heat storage heat exchanger 8 and a liquid subcooling heat exchanger 22 are provided, and the heat storage heat exchanger 8 is connected to the outlet side of the condenser 2 and the compressor 1. It is installed between the suction side. A second throttling mechanism 19 is provided on the inlet side of the heat storage heat exchanger 8, and the liquid subcooling heat exchanger 22 includes the condenser 2 and the first pressure reducing mechanism 3.
Is arranged so as to bypass the main refrigerant circuit 24.

During the heat storage operation which is the nighttime operation by the heat storage type cooling device having the above-mentioned structure, the opening / closing devices 11, 1 are used.
When 2 is closed, the switchgear 11 is opened, and the compressor 1 is operated, the high-temperature high-pressure gas refrigerant from the compressor 1 dissipates heat in the condenser 2, condenses itself into liquid, and stores heat having the second pressure reducing mechanism 19. And enters the heat-like heat exchanger 8 as a low temperature liquid gas two-phase fluid by adiabatic expansion by the second pressure reducing mechanism 19.
The heat is removed from the heat storage medium 6, and the heat storage medium 6 itself evaporates to gas and returns to the compressor 1 via the accumulator 5. By this operation, the heat storage medium 6 is frozen to store low-temperature heat.

When the liquid supercooling operation is performed by utilizing heat storage in the daytime, when the switchgear 10 and 12 in FIG. 15 are closed, the switchgear 11 is opened, and the compressor 1 is operated, the compressor 1 is operated. The high-temperature high-pressure gas refrigerant of is radiated by the condenser 2,
It is condensed and liquefied and sent to the liquid supercooling circuit 23,
The liquid refrigerant is further cooled by the heat storage medium 6, becomes supercooled liquid and is sent to the first pressure reducing mechanism 3, where it adiabatically expands and becomes a low temperature liquid gas two-phase fluid and enters the evaporator 4. Here, the heat is taken from the surroundings to cool it, and it is evaporated and gasified, and returns to the compressor 1 through the accumulator 5. When the operation at this time is represented on the Mollier diagram, the operation is expanded laterally by the supercooling enthalpy as shown in FIG. 16, the compressor input enthalpy (Δic) remains the same, and the evaporation enthalpy for cooling is Δ Increase from ie1 to Δie2.

Further, during the general cooling operation, when the switchgear 10 and 11 in FIG. 15 are closed and the switchgear 12 is opened and the compressor 1 is operated, the high pressure gas refrigerant from the compressor 1 is stored in the condenser 2. Dissipation of heat, condensed and liquefied, is sent to the first pressure reducing mechanism 3 through the main circuit 24, where it adiabatically expands and becomes a low-temperature liquid-gas two-phase liquid and enters the evaporator 4, where heat is taken from the surroundings. Then, it cools itself, evaporates and gasifies, and returns to the compressor 1 through the accumulator.

[0007]

In the conventional heat storage type cooling device which performs each of the above-mentioned operations, the capacity during the liquid subcooling operation is smaller than the capacity during the general cooling operation by the amount of heat which is supercooled. Only big. However, during the liquid subcooling operation, the heat storage amount stored in the heat storage medium by the heat storage operation is used only by the liquid subcooling cooling operation due to its configuration, so the heat storage utilization rate is Δio as shown in FIG. / △ ie
2, that is, about 0.2 to 0.3, and the heat storage utilization rate is about the same even when the load is light. Therefore, even if the remaining amount of heat storage is sufficient, it is used only at the same rate, and the amount of heat storage will be surplus when the load becomes light. This means that in the conventional heat storage type refrigeration cycle device described above, heat storage cannot be efficiently used for the size of the heat storage tank, and although it is called heat storage use, the economic effect of using night power is insufficient. Therefore, the problem remains in the society where the power control during the daytime is not sufficient.

The present invention was developed in view of the above points, and its object is to make more efficient use of the heat storage amount stored in the heat storage medium by the heat storage operation during the midnight power time period. Another object of the present invention is to provide a heat storage type cooling device capable of reducing the power usage time in the daytime and performing cooling and cooling more effectively at an inexpensive midnight power rate.

[0009]

In order to effectively achieve the above object, the present invention has the following structure. That is, a compressor, a condenser, a first pressure reducing mechanism, and an evaporator are sequentially connected to each other, and are connected to a cooling circuit for performing cooling through the evaporator and an inlet side and an outlet side of the evaporator. A heat storage circuit having a heat storage heat exchanger, a heat storage tank provided in a heat exchange relationship with the heat storage heat converter, and storing heat via the heat storage heat exchanger, an outlet side of the evaporator, and the above Refrigerant gas pump provided between the heat storage heat exchanger, a bypass circuit provided in parallel with the refrigerant gas pump, the refrigerant from the condenser at the time of cold storage in the heat storage tank bypasses the evaporator, Further, a valve device for circulating the bypass circuit through the heat storage heat exchanger and a second pressure reducing mechanism connected in parallel with the valve device are provided, and the heat storage energy stored in the heat storage tank is stored as described above. When supplying to the evaporator, Through the heat storing heat exchanger and the second pressure reducing mechanism by medium gas pump is a configuration which is adapted to supply to the inlet side of the evaporator.

A cooling circuit, which is formed by sequentially connecting a compressor, a condenser, a first pressure reducing mechanism and an evaporator, and performs cooling through the evaporator, and an inlet side and an outlet side of the evaporator. A heat storage circuit having a heat storage heat exchanger that communicates with the heat storage tank provided in a heat exchange relationship with the heat storage heat exchanger, and a heat storage tank that stores heat via the heat storage heat exchanger, and to the heat storage tank. At the time of cold storage, a valve device that allows the refrigerant from the condenser to bypass the evaporator to flow to the heat storage heat exchanger, a refrigerant liquid pump connected in parallel with the valve device, and a second pressure reducing mechanism are provided. When the thermal energy stored in the heat storage tank is supplied to the evaporator, the heat energy is supplied to the inlet side of the evaporator through the heat storage heat exchanger, the refrigerant liquid pump, and the second pressure reducing mechanism. It is a configuration that allows it.

[0011]

With the above-described structure, when the cold storage heat stored in the nighttime heat storage operation is used for the daytime cooling operation time, only the cold discharge operation is performed in which the cold storage heat is used when the load is smaller than a predetermined value. When the load is larger than a predetermined value, the cooling operation and the general cooling operation can be performed at the same time.

[0012]

【Example】

Example 1. The first embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing a heat storage type cooling device of the present invention. In the figure, 1 is a compressor, 2 is a condenser, 3 is a first pressure reducing mechanism, 4 is an evaporator, and 5 is an accumulator, which are sequentially connected to 1 to 5 to form a general cooling circuit. 6 is a heat storage medium, for example, water, which is stored in the heat storage tank of 7.

A heat storage heat exchanger 8 exchanges heat with a heat storage medium. A second pressure reducing mechanism 19 is connected between the heat storage heat exchanger inlet 8a and the evaporator 4 inlet. A refrigerant gas pump 18 is connected between the heat storage exchanger outlet 08b and the evaporator 4 outlet to form a refrigerant liquid pump cooling circuit.

Reference numeral 9 denotes a heat storage bypass circuit, which connects the outlet of the first pressure reducing mechanism 3 and the heat storage heat exchanger inlet 8a to the compressor 1, the condenser 2, the first pressure reducing mechanism 3, and the heat storage. The bypass circuit 9, the heat storage heat exchanger, and the accumulator 5 are sequentially connected to form a heat storage circuit.

FIG. 2 is a circuit diagram showing the operation during heat storage operation, which is mainly the operation in the midnight power time zone.
0, 11, 12 are closed, and switchgear 13, 14, 15, 1
6 and 20 are opened and the refrigerant gas pump 18 is stopped,
When the compressor 1 is operated, the high-temperature high-pressure gas refrigerant from the compressor 1 radiates heat in the outdoor heat exchanger 2, condenses itself into liquid, and adiabatically expands in the first decompression mechanism 3, resulting in a low-temperature liquid-gas two-phase fluid. Becomes the heat storage heat exchanger 8 and takes heat from the heat storage medium,
The gas itself evaporates and returns to the compressor 1 through the accumulator 5. By this operation, the heat storage medium 6 is frozen to store low-temperature heat. Fig. 3 shows the operating state of the refrigeration cycle on the Mollier diagram at that time. In the figure, Δic is the compressor enthalpy Δie is the evaporation enthalpy.

When the cooling load in the daytime is less than a predetermined value and the cooling operation is performed by utilizing heat storage, the switchgear 10, 14, 16, 20 is closed and the switchgear 11, 12 is closed as shown in FIG. , 15, 17, 20 are opened and the refrigerant gas pump 18 is operated without operating the compressor 1, the low temperature and low pressure gas refrigerant boosted by the refrigerant gas pump 18 is
Enters the heat storage heat exchanger 8, applies heat to the heat storage medium, condenses itself into liquid, and adiabatically expands by the second pressure reducing mechanism 19,
It becomes a low-temperature liquid gas two-phase fluid and flows into the evaporator 4, where it takes heat from the surroundings and is cooled, and itself evaporates and gasifies, and then returns to the refrigeration gas pump 21 again.

FIG. 5 shows a change on the Mollier diagram of the refrigeration cycle at this time. In the figure, Δigp is the refrigerant gas pump enthalpy, Δic is the compressor enthalpy, and Δie is the evaporation enthalpy. Since this cooling operation is performed at an almost equivalent pressure at which the evaporation action is slightly lower than the condensation temperature, the same amount of refrigerant can be forcedly circulated with an enthalpy significantly smaller than the enthalpy of the compressor 1, and compared with the compressor 1. High C.
O. Achieve P operation. Further, by setting the heat storage amount to a predetermined value or more, it is possible to perform all the cooling loads by the cooling operation and also perform the cooling operation during the peak load time.

When the cooling load in the daytime is equal to or more than a predetermined value, the opening / closing devices 13, 14, 20 are closed and the opening / closing devices 10, 11, 12, 15, 16, 17 are opened as shown in FIG. 1. When both the refrigerant gas pumps 18 are operated, the general cooling operation and the cooling operation are simultaneously performed, and the combined operation is performed. At that time, in the evaporator 4, the time when only the general cooling operation or only the cooling operation is performed is combined. A large amount of refrigerant flows. The change on the Mollier diagram of the refrigeration cycle at this time is shown in FIG. 7, where Δic is the compressor enthalpy, Δic
c is the general cooling side condensation enthalpy, Δicp is the cooling side condensation enthalpy, Δigp is the refrigerant liquid pump enthalpy, Δi
e is the enthalpy of vaporization.

In this refrigeration cycle, since the ratio of the refrigerant circulation amount of the refrigerant gas pump to the refrigerant circulation amount of the compressor can be designed arbitrarily, the ratio of the cooling operation to the total cooling load and the general cooling operation can be set arbitrarily. However, in actuality, the heat storage operation performed at night is the compressor 1 (drive source for general cooling operation).
Since the cooling operation time in the daytime and the heat storage operation time in the nighttime are almost the same, it is appropriate that the cooling capacity by the general cooling operation and the cooling capacity by the cooling operation are almost the same. Also here
The larger the proportion of the cooling operation, the higher the heat storage dependency rate and the smaller the power consumption of the heat storage type cooling device during the cooling operation.

An example of the cooling load during the daytime cooling operation, the general cooling load and the nighttime cold storage operation load described above is shown in FIG. Figure Q ₃ are cold-storage operation load, Q ₂ is allowed to cool operating load, Q ₁ -Q ₂ is generally cooling operation load.

Example 2. Embodiment 2 of the present invention will be described below with reference to FIG.
~ It demonstrates based on FIG. FIG. 9: is a figure which shows the heat storage type cooling device of this invention. In the figure, 1 is a compressor, 2 is a condenser,
3 is a first decompression mechanism, 4 is an evaporator, and 5 is an accumulator, which are sequentially connected to 1 to 5 to form a general cooling circuit. 6 is a heat storage medium, for example, water, which is stored in the heat storage tank of 7.

Reference numeral 8 denotes a heat storage heat exchanger for exchanging heat with the heat storage medium. A refrigerant liquid pump 21 and a second pressure reducing mechanism 19 are provided between the heat storage heat exchanger inlet 8a and the evaporator 4 inlet. They are sequentially connected, and a refrigerant liquid pump cooling circuit is formed by connecting the heat storage heat exchanger outlet 8b and the evaporator 4 outlet. Reference numeral 9 denotes a heat storage bypass circuit, which connects the outlet of the first pressure reducing mechanism 3 and the heat storage heat exchanger inlet 8a, and includes the compressor 1, the condenser 2, the first pressure reducing mechanism 3, and the heat storage bypass. The circuit 9, the heat storage heat exchanger, and the accumulator 5 are sequentially connected to form a heat storage circuit.

FIG. 10 is a circuit diagram showing the operation during the heat storage operation, which is the operation mainly in the midnight power time zone.
0, 11, 12 are closed, and switchgear 13, 14, 15, 1
6, the compressor 1 is opened with the refrigerant liquid pump 21 stopped.
When operating, the high temperature high pressure gas refrigerant from the compressor 1 radiates heat in the outdoor heat exchanger 2, condenses itself into liquid, and adiabatically expands in the first pressure reducing mechanism 3 to become a low temperature liquid gas two-phase fluid. The heat enters the heat storage heat exchanger 8, takes heat from the heat storage medium, vaporizes itself, and returns to the compressor 1 via the accumulator 5. By this operation, the heat storage medium 6 is frozen to store low-temperature heat.

When the cooling load in the daytime is less than a predetermined value, when the cooling operation is performed by utilizing the heat storage, the opening / closing devices 10, 14, 16 are closed as shown in FIG.
When the refrigerant liquid pump 21 is operated without opening the compressors 1, 1, 15, 15 and 17, the low-temperature, low-pressure supercooled refrigerant boosted by the refrigerant liquid pump 21 is caused by the second pressure reducing mechanism 19. It slightly expands adiabatically and enters the evaporator 4, where it takes heat from the surroundings and is cooled to evaporate itself into gas, and returns to the compressor 1 via the accumulator 5.

The change on the Mollier diagram of the refrigeration cycle at this time is shown in FIG. 12, where Δiep is the refrigerant liquid pump enthalpy and Δie is the evaporation enthalpy. This cooling operation is performed at an almost equivalent pressure at which the evaporation action is slightly higher than the condensing pressure, and most of the heat transfer is covered by the latent heat change, so that the refrigerant liquid pump 21 can circulate the liquid and the above-mentioned liquid A pump with a small power enough to absorb the pressure loss for even distribution will suffice, and a condensation heat difference of about the same amount as the evaporation heat difference for cooling will be released to the heat storage medium. Only 10 times as high as the gas pump. O. Achieve P operation. Further, by setting the amount of high heat to a predetermined value or more, it is possible to perform all the cooling loads in the cooling operation and perform the cooling operation during the peak load time.

When the cooling load in the daytime is equal to or greater than a predetermined value, the switchgear 13, 14 is closed and the switchgear 10, 11, 12, 15, 16, 17 is opened as shown in FIG. When both of the liquid pumps 21 are operated, the general cooling operation and the cooling operation are simultaneously performed. At that time, in the evaporator 4, the total refrigerant flow rate when only the general cooling operation or only the cooling operation is performed. Become. The change on the Mollier diagram of the refrigeration cycle at this time is shown in FIG. 14, in which Δic is the compressor enthalpy Δicc is the general cooling side condensation enthalpy, Δicp is the cooling side condensation enthalpy, and Δie.
p is the refrigerant liquid pump enthalpy, and Δie is the evaporation enthalpy.

In this refrigerant cycle, since the ratio of the refrigerant circulation amount of the refrigerant liquid pump to the refrigerant circulation amount of the compressor can be set arbitrarily, the ratio of the cooling operation and the general cooling operation to the total cooling load can be set arbitrarily. However, in actuality, the heat storage operation performed at night uses the compressor 1 (driving source for the general cooling operation), and since the daytime cooling operation time and the nighttime heat storage operation time are almost the same, the cooling capacity by the general cooling operation and the cooling operation is reduced. It is reasonable that they are almost equal. Further, here, the larger the proportion of the cooling operation, the higher the heat storage dependency rate, and the smaller the power consumption of the heat storage type cooling device during the cooling operation.

[0028]

As described above, in the heat storage type cooling device of the present invention, the heat storage dependency rate on the cooling load during the daytime becomes high and the dependency rate can be arbitrarily designed, so that the compressor can be operated during peak hours. It can be operated with 100% heat storage dependency without running. In addition, if the heat storage request rate during the peak load in the summer is 50%, when the load is smaller than that, for example, the heat storage dependency rate is 80% in the morning and evening, or during the interim period, the entire cooling load for one day can be covered by heat storage. it can.

Further, the refrigeration cycle utilizing the heat storage exhibits the same cooling capacity as the general cooling operation by the compressor, so that the operating power consumption can be greatly reduced as compared with the compressor,
C. P. There is an effect that O becomes high.

[Brief description of drawings]

FIG. 1 is a cycle diagram of a heat storage type cooling device according to an embodiment of the present invention.

FIG. 2 is an operation diagram during heat storage operation.

FIG. 3 is a Mollier diagram during heat storage operation.

FIG. 4 is an operation diagram during a cooling operation.

FIG. 5 is a Mollier diagram during a cooling operation.

FIG. 6 shows an operation during a merge operation.

FIG. 7 is a Mollier diagram during the merge operation.

FIG. 8 shows each operation and cooling load at the time of merging operation.

FIG. 9 is a cycle diagram of a heat storage type cooling device according to a second embodiment of the present invention.

FIG. 10 is an operation diagram of the second embodiment during a cold storage operation.

FIG. 11 is an operation diagram of the second embodiment during a cooling operation.

FIG. 12 is a Mollier diagram during the cooling operation of the second embodiment.

FIG. 13 is an operation diagram of the second embodiment during a merge operation.

FIG. 14 is a Mollier diagram during the merge operation of the second embodiment.

FIG. 15 is a cycle diagram of a conventional heat storage type cooling device.

FIG. 16 is a Mollier diagram during a conventional liquid supercooling operation.

[Explanation of symbols]

1 Compressor 2 Condenser 3 First decompression mechanism 4 Evaporator 6 Heat storage medium 7 Heat storage tank 8 Heat storage heat exchanger 8a Heat storage heat exchanger inlet 8b Heat storage heat exchanger outlet 9 Heat storage bypass circuit 10, 11, 12, 13, 14, 15, 16, 17, 2
0 Switchgear 18 Refrigerant gas pump 19 Second pressure reducing mechanism 21 Refrigerant liquid pump 22 Liquid supercooling heat exchanger 23 Liquid supercooling circuit 24 Main refrigerant circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masami Imanishi 6-566 Tehira, Wakayama City Wakayama Works, Mitsubishi Electric Corporation (72) Inventor Kenzo Kurahashi 6-566 Tehira, Wakayama Mitsubishi Electric Company Co., Ltd. Wakayama Factory

Claims (2)

[Claims] 1. A cooling circuit, which is formed by sequentially connecting a compressor, a condenser, a first pressure reducing mechanism and an evaporator, and performs cooling through the evaporator, and an inlet side and an outlet side of the evaporator. A heat storage circuit having a heat storage heat exchanger that communicates with the heat storage tank and a heat storage tank that is provided in a heat exchange relationship with the heat storage heat converter and stores heat via the heat storage heat exchanger, and an outlet of the evaporator. A refrigerant gas pump provided between the side and the heat storage heat exchanger, a bypass circuit provided in parallel with the refrigerant gas pump, the refrigerant from the condenser at the time of cold storage in the heat storage tank to the evaporator. A heat storage device that includes a valve device that bypasses and circulates to the bypass circuit through the heat storage heat exchanger, and a second pressure reducing mechanism that is connected in parallel with the valve device, and that stores heat in the heat storage tank. When supplying energy to the above evaporator, A heat storage type cooling device characterized in that the refrigerant gas pump supplies the heat to the inlet side of the evaporator through the heat storage heat exchanger and the second pressure reducing mechanism. 2. A cooling circuit, which is formed by sequentially connecting a compressor, a condenser, a first pressure reducing mechanism and an evaporator, and performs cooling through the evaporator, and an inlet side and an outlet side of the evaporator. A heat storage circuit having a heat storage heat exchanger that communicates with the heat storage tank provided in a heat exchange relationship with the heat storage heat exchanger, and a heat storage tank that stores heat via the heat storage heat exchanger, and to the heat storage tank. At the time of cold storage, a valve device that allows the refrigerant from the condenser to bypass the evaporator to flow to the heat storage heat exchanger, a refrigerant liquid pump connected in parallel with the valve device, and a second pressure reducing mechanism are provided. When the thermal energy stored in the heat storage tank is supplied to the evaporator, the heat energy is supplied to the inlet side of the evaporator via the heat storage exchanger, the refrigerant liquid pump, and the second pressure reducing mechanism. A heat storage type cooling device characterized by the above.