JP2003028520A - Regenerative refrigerating plant - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerative refrigerating plant that can store heat in a heat storage unit simultaneously with cooling operation without obstructing the cooling of coolers for low pressure-side loads. SOLUTION: This regenerative refrigerating plant is provided with a refrigerating machine 1 having a compressor 11 and a condenser 12, the coolers 2a and 2b for low pressure-side loads having a pressure reducing mechanism 31 and evaporators 22a and 22b, and a heat exchanger 35 for heat storage. This refrigerating plant is also provided with a control means which sets the upper limit of the quantity of a refrigerant flowing to the heat storage unit when cooling operation for cooling the cooler 2a and 2b and heat storing operation for storing heat in the heat storage unit are simultaneously performed.

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 refrigeration system, and more particularly to a heat storage type refrigeration system provided with a heat storage unit having a heat storage medium capable of storing heat therein and having a heat exchanger for heat storage. .

[0002]

2. Description of the Related Art Conventionally, in an air conditioner having a heat storage type refrigeration cycle, a liquid refrigerant to an indoor heat exchanger (use side heat exchanger) is disclosed, for example, in Japanese Patent Laid-Open No. 3-186160. By controlling the flow rate by the flow rate control valve to limit the heat, the heat storage in the heat storage unit is preferentially performed, and the indoor cooling and the heat storage operation in the heat storage unit are simultaneously performed.

[0003]

In the heat storage type refrigerating cycle in the above air conditioner, the flow rate of the liquid refrigerant to the cooler for the low pressure side load is controlled by the flow rate control valve to limit the flow rate of the liquid refrigerant, so that the low pressure side during the heat storage operation. The influence of load fluctuations of the load cooler is minimized, and heat is stored preferentially in the heat storage unit. For this reason, in the case of use for a refrigerating / refrigerating device in which the load of the low-pressure side load cooler is large, even when the load of the low-pressure side load cooler increases during heat storage operation, the liquid refrigerant flow rate is within the limit range. However, it could not be said to be able to adequately cope with it because it could only follow.

An object of the present invention is to provide a heat storage type refrigerating apparatus capable of simultaneously storing heat in a heat storage unit without hindering cooling of a low-voltage load cooler.

[0005]

In order to solve the above-mentioned problems, the constitution of the invention of a heat storage type refrigerating apparatus according to the present invention is a refrigerator having a compressor and a condenser, and a low pressure having a pressure reducing mechanism and an evaporator. In a heat storage type refrigerating apparatus comprising a side load cooler and a heat storage unit having a heat storage heat exchanger that contains a heat storage medium, a cooling operation for cooling the low pressure side load cooler and heat storage for storing heat in the heat storage unit. The control means is provided for setting an upper limit on the amount of refrigerant flowing through the heat storage unit when the operation and the operation are performed at the same time.

In order to solve the above-mentioned problems, another structure of the heat storage type refrigerating apparatus according to the present invention is a refrigerator having a compressor and a condenser whose rotation speed is controlled by frequency control of an inverter, and a pressure reducing mechanism. And a low pressure side load cooler having an evaporator, and a heat storage unit having a heat storage medium and a heat storage unit having a heat storage heat exchanger,
Control means is provided for adjusting the inlet pressure of the compressor and controlling the outlet temperature of the heat storage heat exchanger by changing the frequency of the inverter and the inlet pressure of the heat storage heat exchanger.

Specifically, the control means controls the operating capacity of the refrigerator on the basis of the inlet pressure of the compressor, and the heat storage heat exchange on the basis of the outlet temperature of the heat storage heat exchanger. This is a control means for controlling the valve opening on the inlet side of the container. Further, the valve opening degree on the inlet side of the heat storage heat exchanger is controlled to be constant for a predetermined time from the start of heat storage, and then the valve opening degree is controlled based on the outlet side temperature of the heat storage heat exchanger.

In order to solve the above-mentioned problems, a structure of still another invention of the heat storage type refrigerating apparatus according to the present invention is a refrigerator having a compressor and a condenser, and a low pressure side load having a pressure reducing mechanism and an evaporator. In a heat storage type refrigerating apparatus comprising a cooler and a heat storage unit having a heat storage medium heat storage medium built therein, a cooling operation for cooling the low-voltage load cooler, and a heat storage operation for storing heat in the heat storage unit. When simultaneously performing and, the control means for setting an upper limit to the amount of refrigerant flowing to the heat storage unit, the control means, the control means for controlling the operating capacity of the refrigerator based on the inlet side pressure of the compressor , And control means for controlling the valve opening degree on the inlet side of the heat storage heat exchanger based on the outlet side temperature of the heat storage heat exchanger, a predetermined time from the start of heat storage, the inlet side of the heat storage heat exchanger Constant valve opening It is Gosuru thing.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cycle system diagram of an embodiment of a heat storage type refrigeration system according to the present invention. In the figure, the heat storage type refrigeration system is composed of a refrigerator 1 composed of a compressor 11 and a condenser 12, expansion valves 21a and 21b for coolers, evaporators 22a and 22b, and solenoid valves 23a and 23b for coolers. Multiple low-voltage load coolers 2 connected in parallel
a, 2b, heat storage expansion valve 31, solenoid valves 32a, 32
b, 32c, 32d, a heat storage tank 33, a heat storage medium 34, a heat storage heat exchanger 35, and a low-voltage side load cooler 2a,
2b and the heat storage unit 3 connected in parallel are provided, and a refrigeration cycle is configured by these devices.

Further, the heat storage refrigerating apparatus has an operating capacity control means A for controlling the operating capacity of the compressor 11 by changing, for example, the inverter frequency, and an opening of the heat storage expansion valve 31. And the opening degree control means B of. Further, a pressure detector 13 for detecting the refrigerant pressure is provided on the inlet side of the refrigerator 1, and a refrigerant temperature detector 36 for detecting the temperature of the refrigerant is provided on the outlet side of the heat storage heat exchanger 35. Has been. The operating capacity control means A controls the rotational speed of the compressor 11 based on the pressure detected by the pressure detector 13 to control the operating capacity, and the opening degree control means B controls the refrigerant temperature. Detector 3
The opening degree of the expansion valve 31 for heat storage is adjusted based on the temperature detected by 6 to control the opening degree. Generally, a cooling unit is composed of the refrigerator 1 and coolers 2a and 2b for low-voltage loads such as a showcase.

In the above structure, the operation is performed as follows. Storage of heat in the heat storage tank 33 and cooler 2 for low-voltage load
At the time of simultaneous operation of cooling and heat storage for simultaneously cooling a and 2b, the solenoid valves 32a and 32c are opened and the solenoid valves 32b and 3 are
Keep 2d closed. As indicated by the solid thick line, the compressor 11
The gas refrigerant compressed by is heat-exchanged in the condenser 12 and liquefied, and the liquefied refrigerant is cooled by the low-pressure load coolers 2a and 2b.
And the heat storage unit 3 are simultaneously supplied to cool and
Two refrigeration cycles for heat storage are configured.

That is, the liquefied refrigerant is transferred to the heat storage expansion valve 3
1 is decompressed and absorbs heat from the heat storage medium 34 in the heat storage tank 33 when flowing through the heat storage heat exchanger 35 to cool the heat storage medium 34, and the refrigerant gasified by cooling the heat storage medium 34 is a solenoid valve. It returns to the compressor 11 through 32c, and the refrigerating cycle of heat storage operation is comprised. On the other hand, the solenoid valve 32
The liquefied refrigerant that has passed through a is cooled by solenoid valves 23a, 23b.
The pressure is reduced by the expansion valves 21a and 21b for the cooler, the low-pressure side load is cooled by the evaporators 22a and 22b and returned to the compressor 11, and the refrigeration cycle of the cooling operation is constituted.

As described above, the heat storage type refrigerating apparatus comprises two refrigerating cycles capable of simultaneously performing the heat storage operation and the cooling operation. In general, the heat storage operation is performed by using cheap nighttime discounted electric power and by using the surplus refrigerating capacity of the refrigerator 1 at night when the cooling load is small.

The above description is about the basic operation at the time of simultaneous operation of cooling and heat storage. However, a plurality of low-voltage side load coolers 2a and 2b are combined to form each low-voltage side load cooler 2a. , 2b have different internal temperatures, or when the low-pressure load coolers 2a, 2b form a group and the internal temperatures of the respective groups are different, the cooler solenoid valves 23a, individually or for each group, Refrigerant is supplied by opening and closing 23b.

Further, if it becomes unnecessary to supply the refrigerant to the low-voltage load coolers 2a and 2b, only the heat storage operation can be performed. Further, when the heat storage in the heat storage medium 34 is completed, the heat storage operation may be stopped and only the low-voltage load coolers 2a and 2b may be operated.

The control of the operating capacity control means A and the opening degree control means B will be further described. The pressure corresponding to the evaporation temperature T1 required to cool the low-voltage load coolers 2a and 2b is set as the control target value of the operating capacity control means A. Next, at the evaporation temperature T1 maintained by the operating capacity control means A, the control target value of the temperature detected by the refrigerant temperature detector 36 is determined by adjusting the opening degree of the opening degree control means B.

Next, during night operation, the excess refrigerant supplied to the heat storage heat exchanger 35 is removed from the refrigerant supply capacity of the refrigerator 1 by removing the refrigerant necessary for cooling the low-pressure load coolers 2a and 2b. In order to provide an upper limit to the refrigerant, the upper limit opening W1 of the heat storage expansion valve 31 on the inlet side of the heat storage heat exchanger 35 is set (see FIG. 2). That is, the low-voltage load coolers 2a, 2
If the load capacity of b is constant throughout the year, the upper limit opening W1 does not need to be changed after it has been set once, but if it changes according to the four seasons or the like, it is changed accordingly.
Further, the required heat storage amount of the next day may be predicted and the heat storage amount may be limited.

Due to the above, the coolers 2a, 2 for the low-voltage load
When the load of b is increased, the pressure detected by the pressure detector 13 is increased, and accordingly, the operating capacity control means A acts so as to increase the operating capacity of the compressor 11. That is, by changing the inverter frequency and the pressure on the inlet side of the heat storage heat exchanger 35, the pressure on the inlet side of the compressor 11 is adjusted so that the outlet temperature of the heat storage heat exchanger 35 is optimized. To be done.

On the other hand, when the temperature detected by the refrigerant temperature detector 36 rises, the opening degree of the heat storage expansion valve 31 is increased, and the opening degree control means B acts so that heat is sufficiently stored in the heat storage unit 3. . However, since the upper limit opening W1 is set in the heat storage expansion valve 31, the amount of refrigerant supplied to the low pressure side load coolers 2a and 2b cools the low pressure side load coolers 2a and 2b. The opening degree of the heat storage expansion valve 31 is controlled so as to be in a range that secures the amount of refrigerant required for the above.

In the cooling operation utilizing the heat storage of the heat storage tank 33, the heat storage operation is started from the state where the heat storage heat exchanger 35 is filled with the liquid refrigerant (when the liquid refrigerant stays without vaporization). Even in such a case, by keeping the expansion valve 31 for heat storage constant at the initial opening W2 smaller than the upper limit opening W1 for a predetermined time from the start of the heat storage operation, excessive refrigerant is supplied to the heat exchanger 35 for heat storage. Can be prevented.

According to this embodiment, since the upper limit opening W1 is set in the heat storage expansion valve, the amount of refrigerant supplied to the low pressure side load cooler cools the low pressure side load cooler. Since the amount of the refrigerant does not become less than that required, the heat storage operation can be performed in the refrigeration cycle that does not hinder the cooling of the low-voltage load cooler (see FIG. 2). In addition, the compressor 11 may be configured such that a plurality of constant speed compressors are combined to control the operating capacity. In addition, the heat storage heat exchanger 3 is provided by a multi-stage depressurization mechanism combining a plurality of capillaries.
The pressure on the inlet side of 5 may be controlled.

[0022]

As described above, according to the present invention,
Based on the pressure detected by the pressure detector at the refrigerator inlet, controlling the operating capacity control means of the refrigerator, based on the temperature detected by the refrigerant temperature detector at the heat storage exchanger outlet side, the opening control means By controlling the opening degree of the heat storage expansion valve and limiting the opening degree of the heat storage expansion valve, heat is stored in the heat storage unit without hindering the cooling of the low-voltage load cooler. It is possible to provide a heat storage type refrigerating device that can be used.

[Brief description of drawings]

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

FIG. 2 is a diagram showing a transition of an opening of a heat storage expansion valve in the embodiment of FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Refrigerator, 2a, 2b ... Low-voltage side load cooler, 3 ... Heat storage unit, 11 ... Compressor, 12 ... Condenser, 13 ... Pressure detector, 21a, 21b ... Cooler expansion valve, 22a, 2
2b ... Evaporator, 23a, 23b ... Cooler solenoid valve, 31
... Heat storage expansion valve, 32a, 32b, 32c, 32d ... Electromagnetic valve, 33 ... Heat storage tank, 34 ... Heat storage medium, 35 ... Heat storage heat exchanger, 36 ... Refrigerant temperature detector, A ... Operating capacity control means, B ... Opening control means, W1 ... upper limit opening, W2 ... initial opening.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Naoki Hattori             390 Muramatsu, Shimizu City, Shizuoka Prefecture Hitachi Shimizu En             Inside Genialing Co., Ltd. (72) Inventor Shin Otahara             390 Muramatsu, Shimizu City, Shizuoka Prefecture Hitachi Shimizu En             Inside Genialing Co., Ltd. (72) Inventor Yoshimasa Akatsuka             Chubuden, 1 Higashishinmachi, Higashi-ku, Nagoya-shi, Aichi             Power Co., Ltd. (72) Inventor Miwako Fujita             Chubuden, 1 Higashishinmachi, Higashi-ku, Nagoya-shi, Aichi             Power Co., Ltd.

Claims (5)

[Claims] 1. A heat storage type comprising a refrigerator having a compressor and a condenser, a cooler for a low pressure side load having a pressure reducing mechanism and an evaporator, and a heat storage unit having a heat storage medium and a heat storage heat exchanger. In the refrigeration system, when performing a cooling operation for cooling the low-voltage load cooler and a heat storage operation for storing heat in the heat storage unit at the same time, a control means for setting an upper limit to the amount of refrigerant flowing in the heat storage unit is provided. A heat storage type refrigerating device. 2. A heat exchanger for storing heat, which includes a refrigerator having a compressor and a condenser whose rotation speed is controlled by frequency control of an inverter, a cooler for a low-pressure side load having a pressure reducing mechanism and an evaporator, and a heat storage medium. In a heat storage type refrigerating apparatus comprising a heat storage unit having a compressor, the inlet pressure of the compressor is adjusted by changing the frequency of the inverter and the inlet pressure of the heat storage heat exchanger, and the outlet of the heat storage heat exchanger is adjusted. A heat storage type refrigerating apparatus comprising a control means for controlling a side temperature. 3. The control means controls the operating capacity of the refrigerator based on the inlet side pressure of the compressor, and the heat storage heat exchanger based on the outlet side temperature of the heat storage heat exchanger. 3. The heat storage type refrigerating apparatus according to claim 1 or 2, which is a control means for controlling a valve opening degree on the inlet side of the. 4. The valve opening on the inlet side of the heat storage heat exchanger is controlled to be constant for a predetermined time from the start of heat storage, and then the valve opening is controlled based on the outlet temperature of the heat storage heat exchanger. The heat storage type refrigeration system according to claim 1 or 2. 5. A heat storage device comprising: a refrigerator having a compressor and a condenser; a cooler for a low pressure side load having a decompression mechanism and an evaporator; and a heat storage unit having a heat storage medium and a heat exchanger for heat storage. In a refrigeration system, when performing a cooling operation for cooling the low-pressure side load cooler and a heat storage operation for storing heat in the heat storage unit at the same time, a control means for setting an upper limit to the amount of refrigerant flowing in the heat storage unit is provided. The control means controls the operating capacity of the refrigerator based on the inlet pressure of the compressor, and the inlet side of the heat storage heat exchanger based on the outlet temperature of the heat storage heat exchanger. Is a control means for controlling the valve opening of the heat storage type refrigerating apparatus, wherein the valve opening on the inlet side of the heat storage heat exchanger is controlled to be constant for a predetermined time from the start of heat storage.