JP4512947B2 - Thermal storage refrigeration system - Google Patents

Description

    The present invention relates to a regenerative refrigerating apparatus, and more specifically to a regenerative refrigerating apparatus suitable for a refrigerating load such as a freezing or refrigerated showcase or a refrigerating load of an air conditioner.

  This type of regenerative refrigeration system uses discounted electricity at night or uses the excess of the freezing capacity of the chiller at night when the cooling load is reduced to store cold heat, increasing the cooling load It is known as an apparatus that saves energy and reduces energy costs by using heat storage cold energy during the daytime. Further, in such a heat storage type refrigeration apparatus, various proposals have been made to optimize the heat storage capacity and the refrigerator capacity by setting the heat storage amount in accordance with the fluctuation of the cold load at daytime and nighttime.

  For example, as a rational method of switching and controlling the heat storage operation or the heat storage use operation with a period of one day, the remaining heat storage amount is estimated based on the heat storage operation time for the past several times (a few days), and the next heat storage use operation In the case where it is estimated that there is a remaining heat storage amount necessary for the heat storage, a heat storage refrigeration apparatus is proposed in which the heat storage operation is not performed (see Patent Document 1).

  In addition, by calculating the required heat storage amount from the past heat storage consumption, the necessary heat storage operation time of the heat source device 1 is calculated, and the heat storage operation of the heat source device is controlled by calculating back the heat storage operation start time from the heat storage end time. A type refrigeration apparatus has been proposed (see Patent Document 2).

  In addition, a regenerative refrigeration system has also been proposed that enables high-precision control by predicting the load of the day with the actual load of the previous day, and enables effective use of heat storage and reduction of running costs by reducing the operating time of the chiller. (See Patent Document 3).

  On the other hand, in a regenerative air conditioner that switches to heat storage use operation when the outside air temperature or power consumption exceeds the set value, the heat storage use operation time is counted, and when the heat storage use operation time is shorter than the reference value Set the next heat storage operation time short, and if it is long, set the next heat storage operation time long to ensure an appropriate amount of heat storage commensurate with the daytime air conditioning operation time and prevent wasteful power consumption. Has been proposed (see Patent Document 4).

Japanese Patent No. 3225460 JP 2000-130898 A JP 2000-337683 A JP 2001-336806 A

    In the heat storage type refrigeration apparatus described in Patent Documents 1 to 3, excessive heat storage can be avoided in an intermediate period or the like where the cooling load is small by estimating the remaining heat storage amount. However, there is a drawback that various measuring or detecting devices or complicated control algorithms are required in order to increase the accuracy of the estimation of the remaining heat storage amount and the prediction of the heat storage amount necessary for the next heat storage use operation.

  Moreover, in the heat storage type refrigeration apparatus described in Patent Documents 1 to 3, if an error occurs in the estimation of the heat storage remaining amount or the heat storage amount necessary for the heat storage use operation, excessive heat is stored during the heat storage operation. The heat transfer tubes are stressed during the next heat storage operation due to residual ice adhering to the heat transfer tubes of the heat storage tank, which may reduce the reliability. Therefore, it is desired to realize optimal heat storage amount control with a simple device or the like.

  In order to satisfy such a demand, a heat storage type air conditioner described in Patent Document 4 has been proposed. In the heat storage type air conditioner described in Patent Document 4, the heat storage use operation time is measured, and the length of the next heat storage operation time is controlled according to the length of the heat storage use operation time. Thus, the heat storage amount control with a simple configuration can be realized. However, although the heat storage operation time is shortened even in the intermediate period when the cooling load is small, etc., it is still unsatisfactory in terms of energy saving and energy cost reduction because the same heat storage operation is performed as in the summer period where the cooling load is large. There are enough aspects.

  Therefore, when the amount of heat storage is low, such as in the intermediate period when the cold load is small, it is desired to perform efficient heat storage control by performing a heat storage operation that is leveled at the time when discount electricity can be used at night. ing.

    The present invention provides a regenerative refrigerating apparatus capable of carrying out an efficient regenerative operation with zero remaining heat storage and leveling the discounted power at night when switching from regenerative operation to regenerative operation. The task is to do.

  The heat storage type refrigeration apparatus according to the present invention sets the target time of the heat storage use operation in advance, calculates the difference between the actual heat storage use operation time and the target time, and reduces the calculated difference next time. In the heat storage operation, the above-mentioned problem is achieved by adjusting the flow rate of the refrigerant flowing in the heat storage tank.

In order to solve the above-described problems, the present invention provides a compressor that compresses a gas refrigerant, a refrigerator that includes a condenser that cools the gas refrigerant compressed by the compressor into a liquid refrigerant, and the refrigerant of the refrigerator A heat storage tank connected to the pipe for storing cold heat, a cooling load connected to the refrigerant pipe of the refrigerator, a heat storage operation for supplying the liquid refrigerant to the heat storage tank, and the cold stored in the heat storage tank. Control means for switching and controlling the heat storage use operation to be supplied to the cold load, and the control means starts the heat storage use operation and ends the heat storage use operation at a temperature at which there is no residual ice in the heat storage tank calculated heat storage utilization operating time to obtain the difference between the thermal storage available operation time and a preset thermal storage utilization target operation time obtained, guess the excess and deficiency of the heat storage amount from the previous SL calculated difference, the next time the excess or deficiency in performing thermal storage operation Hesi, and as an upper limit value of the refrigerant flow rate of the heat storage tank for heat storage using all the preset thermal storage operation time becomes the upper limit flow rate of the refrigerant is set to flow in the heat storage tank It controls the opening degree of the expansion valve for heat storage which decompresses the liquid refrigerant supplied to the said heat storage tank, and the rotation speed of the said compressor .

  In this case, the temperature of the cold storage medium in the heat storage tank that terminates the heat storage use operation can depend on the temperature of the heat storage medium in the heat storage tank or the refrigerant temperature supplied from the heat storage tank to the cold load, for example, the temperature at which residual ice disappears. The heat storage utilization operation is terminated at the set temperature set to.

  Therefore, according to the present invention, the heat storage use operation is continued until the remaining heat storage amount becomes zero, and the heat storage operation that is leveled at the time when the discount power can be used at night is performed. It is possible to suppress the occurrence of stress on the heat transfer tubes of the heat storage tank to ensure the reliability of the heat storage tank, and to carry out an efficient heat storage operation that is leveled at the time when the discount power can be used at night.

  In addition, an upper limit value is set in the refrigerant flow rate upper limit control means for the flow rate of refrigerant flowing in the heat storage tank, and the refrigerant flow rate can be adjusted by controlling the upper limit value. That is, the measurement means 42 and the heat storage amount control means 43 determine the excess or deficiency of the heat storage amount that reduces the difference between the heat storage use operation time and the heat storage use operation target time, and during the heat storage operation so as to reduce the obtained excess or deficiency The upper limit value is corrected for the refrigerant flow rate flowing through the heat storage tank, and the next refrigerant flow rate upper limit value is set in the refrigerant flow rate upper limit control means 41.

  Here, if the heat storage use operation time is longer than the target time, the refrigerant flow rate flowing in the heat storage tank in the next heat storage operation is made smaller than the previous refrigerant flow rate, and if it is shorter, the refrigerant flow rate flowing in the heat storage tank in the next heat storage operation. By making the flow rate larger than the previous refrigerant flow rate, it is possible to control the optimum heat storage amount according to the outside air temperature and seasonal fluctuations with a simple system.

  In the above invention, the control means includes refrigerant flow rate upper limit control means for setting an upper limit value for the refrigerant flow rate flowing in the heat storage tank at the time of the previous heat storage operation; Measurement means for obtaining a heat storage use operation time up to a point of time when the heat storage use operation is terminated based on the temperature of the medium, obtaining a difference between the obtained heat storage use operation time and the heat storage use operation target time, and the obtained A heat storage amount control means that estimates the excess or deficiency of the heat storage amount from the difference, calculates the refrigerant flow increase / decrease amount from the estimated value, and corrects the refrigerant flow rate upper limit during the previous heat storage operation with the refrigerant flow increase / decrease amount, It is possible to control the upper limit value of the flow rate of the refrigerant flowing in the heat storage tank during the heat storage operation.

  Furthermore, the control means can correct the heat storage amount of the next heat storage operation according to a change in the outside air temperature.

In order to solve the above problems, the present invention provides a refrigerator comprising a compressor that compresses a gas refrigerant, a condenser that cools the gas refrigerant compressed by the compressor to form a liquid refrigerant, and the refrigerator. A heat storage tank connected to the refrigerant pipe for storing cold heat, a cooling load connected to the refrigerant pipe of the refrigerator for cooling the object to be cooled, a heat storage operation for supplying the liquid refrigerant to the heat storage tank, and the heat storage tank Control means for switching and controlling the cold energy stored in the heat storage use operation to supply the cold load, the control means starts the heat storage use operation, based on the temperature of the cooling medium in the heat storage tank Obtaining an integral value of the operating capacity of the compressor before and after the end of the heat storage utilization operation at the time of ending the heat storage utilization operation , and integrating the integral value and the operation capacity of the compressor at a preset heat storage utilization target time The difference from the value Guess excess or deficiency of the heat storage amount of the storage tank to reduce the excess or deficiency in performing thermal storage operation for the next time, and the refrigerant of the heat storage tank for heat storage using all the preset thermal storage operation period The upper limit value of the flow rate is set, and the opening degree of the expansion valve for heat storage and the rotation of the compressor that depressurizes the liquid refrigerant supplied to the heat storage tank so that the refrigerant flow rate flowing through the heat storage tank becomes the set upper limit value. It is characterized by controlling the number .

  According to the present invention, when switching from the heat storage use operation to the heat storage operation, it is possible to perform the efficient heat storage operation in which the remaining amount of heat storage is zero and the nighttime discounted power is leveled.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a cycle system diagram showing a configuration of a regenerative refrigerating apparatus according to an embodiment of the present invention. In FIG. 1, the heat storage type refrigeration apparatus is roughly composed of a refrigerator 1, cooling loads 2 a and 2 b, a heat storage unit 3, and a control device 4 that controls these operations. The refrigerator 1 includes a compressor 11 that compresses a gas refrigerant, and a condenser 12 that cools the gas refrigerant compressed by the compressor 11 into a liquid refrigerant. Here, in the refrigerator 1, the suction side of the compressor 11 is connected to the refrigerant pipe 5. The discharge side of the compressor 11 is connected to one end of the condenser 12. The other end of the condenser 12 is connected to the refrigerant pipe 6.

  The cold load 2a includes a cooler expansion valve 21a, an evaporator 22a, and a cooler electromagnetic valve 23a. In this cooling load 2 a, one end of the cooler solenoid valve 23 a is connected to the refrigerant pipe 6. The other end of the cooler solenoid valve 23a is connected to one end of the cooler expansion valve 21a. The other end of the cooler expansion valve 21a is connected to one end of the evaporator 22a. The other end of the evaporator 22 a is connected to the refrigerant pipe 5.

  The cooling load 2b includes a cooler expansion valve 21b, an evaporator 22b, and a cooler electromagnetic valve 23b. In this cooling load 2b, the other end of the cooler solenoid valve 23b is connected to one end of the cooler expansion valve 21b. The other end of the cooler expansion valve 21b is connected to one end of the evaporator 22b. The other end of the evaporator 22 b is connected to the refrigerant pipe 5.

  The heat storage unit 3 includes a heat storage expansion valve 31, electromagnetic valves 32 a to 32 d, a heat storage tank 33, a heat storage medium 34, and a heat storage heat exchanger 35. One end of the heat storage heat exchanger 35 of the heat storage unit 3 is connected to the refrigerant pipe 6 on the condenser 12 side via the heat storage expansion valve 31 and the electromagnetic valve 32 b connected in parallel, and the other end of the heat storage heat exchanger 35. Is connected to the refrigerant pipe 5 on the compressor 11 side via an electromagnetic valve 32c, and to the refrigerant pipe 6 of the cooling load 2a, 2b via an electromagnetic valve 32d. The solenoid valve 32a is connected to the refrigerant piping 6 upstream of the solenoid valve 32d and downstream of the heat storage expansion valve 31 and the solenoid valve 32b. A temperature detector 36 for detecting the refrigerant temperature is provided at the refrigerant outlet of the heat storage heat exchanger 35.

  The control device 4 controls the heat storage expansion valve 31 and the electromagnetic valves 32a to 32d to store the heat storage operation for supplying the liquid refrigerant to the heat storage unit 3, and the cold energy stored in the heat storage unit 3 to the cold loads 2a and 2b. This is a device for switching and controlling the heat storage utilization operation to be supplied. This control device 4 is composed of, for example, a PIC (Peripheral Interface Controller) and its peripheral circuits, and stores an operation command and a program for realizing the control method of the present invention in the PIC, and requires operation. In response to this, the PIC can create a driving command or execute a predetermined program to control a predetermined device.

  The control device 4 may comprehensively control the refrigerator 1, the cooling loads 2 a and 2 b, and the heat storage unit 3.

  FIG. 2 is a block diagram illustrating a detailed configuration of the control device according to the present embodiment. In FIG. 2, the control device 4 roughly includes a refrigerant flow rate upper limit control means 41, a measurement means 42, and a heat storage amount control means 43. These means are implement | achieved when the program required in order to drive the thermal storage type freezing apparatus which concerns on this embodiment is performed by PIC.

  The refrigerant flow rate upper limit control means 41 is configured to set the refrigerant flow rate upper limit value Gmax that flows in the heat storage tank during the previous heat storage operation that has been operated continuously without interposing the heat storage use operation.

The measuring means 42 measures the current heat storage use operation time T from the start of the heat storage use operation to the time when the heat storage use operation is terminated by a signal indicating the remaining amount of heat stored detected by the temperature detector 36. When the difference between the heat storage utilization operation target time setting means 42b for setting the target time T ₀ of the thermal storage usage operating time to operate continuously with no intervening thermal storage operation, and this heat storage utilization operation time T and the target time T ₀ And calculating means 42c for calculating ΔT (= T−T ₀ ) which is (deviation).

The heat storage amount control means 43 is an excess / deficiency heat amount estimation means 43a for estimating the relative excess / deficiency heat amount ΔQ of the heat storage amount based on the refrigerant flow rate upper limit Gmax flowing in the heat storage tank during the previous heat storage operation and the difference ΔT. And a refrigerant flow rate calculation means 43b for calculating an increase / decrease amount ΔG of the refrigerant flow rate upper limit value during a predetermined heat storage operation time to make the estimated heat storage excess / deficiency ΔQ zero, and the calculated increase / decrease amount ΔG The next refrigerant flow rate determining means 43c for adding the refrigerant flow rate upper limit value Gmax to determine the next refrigerant flow rate upper limit value (Gmax + ΔG). Here, the heat storage utilization target time T ₀ of the operation, for example, the refrigerating capacity of the refrigerator 1, diurnal cooling load is set based on conditions such as contract demand.

Next, the operation of the regenerative refrigerating apparatus according to this embodiment configured as described above will be described. First, the general operation | movement operation | movement in the thermal storage type freezing apparatus which concerns on this embodiment is demonstrated.
[In case of simultaneous operation to supply heat to both heat storage and heat load]
In the case of simultaneous operation in which heat storage to the heat storage tank 33 and cold supply to the cold loads 2a and 2b are performed simultaneously, the control device 4 opens the electromagnetic valves 32a and 32c and closes the electromagnetic valves 32b and 32d. As a result, as shown by a solid thick line in the figure, the gas refrigerant compressed by the compressor 11 is liquefied by heat exchange in the condenser 12, and the liquefied liquid refrigerant is cooled by the cold loads 2 a and 2 b and the heat storage unit 3. Are supplied respectively. That is, two refrigeration cycles of the refrigeration cycle of the cold load 2 and the refrigeration cycle of the heat storage unit 3 are configured.

  Here, in one refrigeration cycle, the liquid refrigerant supplied from the refrigerator 1 is depressurized by the heat storage expansion valve 31, and the heat storage medium 34 in the heat storage tank 33 is cooled by the heat storage heat exchanger 35. The gasified gas refrigerant is a refrigeration cycle in a heat storage operation that returns to the compressor 11 through the electromagnetic valve 32c. The other refrigeration cycle passes through the solenoid valve 32a and then passes through the cooler solenoid valves 23a and 23b and is depressurized by the cooler expansion valves 21a and 21b. A refrigeration cycle that returns, and these two refrigeration cycles are configured simultaneously.

  The two refrigeration cycles are configured as a basic operation during the heat storage operation, and the refrigeration loads 2a and 2b are configured by combining a plurality of refrigerated or refrigerated showcases or unit coolers, When the internal temperature is different or when the load constitutes a group and the internal temperature is different for each group, the refrigerant solenoid valves 23a and 23b are opened and closed individually or in groups to supply the refrigerant. Will do.

In this heat storage operation, generally, heat storage operation is performed by using cheap discount electricity at night and using the surplus refrigeration capacity of the refrigerator 1 at night when the cooling load is reduced.
[In the case of other driving]
Further, if there is no need to supply the refrigerant to the cooling loads 2a and 2b, it is possible to perform only the heat storage operation. Furthermore, if the heat storage to the heat storage medium 34 is completed, the heat storage operation can be stopped and the operation of only the cooling loads 2a and 2b can be performed.

  Next, the heat storage operation control operation of the heat storage refrigeration apparatus according to the present embodiment will be described.

[Heat storage operation]
In the heat storage operation, heat storage is performed using all of the actual heat storage operation time set with some allowance for the heat storage operation time determined by the agreement with the electric power company. At this time, the refrigerant flow rate upper limit value Gmax that has flowed into the hour heat storage tank during the actual heat storage operation time during the previous heat storage operation that has been operated continuously without interposing the heat storage use operation is set in the refrigerant flow rate upper limit control means 41. The

Next, the heat storage use time measuring means 42a measures the current heat storage use operation time T from the start of the heat storage use operation to the time when the heat storage use operation is terminated by a signal indicating the remaining amount of heat stored detected by the temperature detector 36. To do. Further, the heat storage utilization target operation time setting unit 42b, the target time T ₀ of the thermal storage usage operating time to operate continuously with no intervening thermal storage operation is set.

ΔT (= T−T) which is a difference (displacement) between the current heat storage use operation time T measured by the heat storage use time measuring means 42a and the target time T ₀ set in the heat storage use operation target time setting means 42b. ₀ ) is calculated by the calculating means 42c. The difference ΔT measured by the calculation means 42c is given to the excess / deficiency heat quantity estimation means 43a.
The excess / deficiency heat amount estimation means 43a calculates the relative excess / deficiency heat amount ΔQ of the heat storage amount based on the refrigerant flow rate upper limit Gmax flowing in the heat storage tank during the previous heat storage operation and the difference ΔT.

  The refrigerant flow rate calculation means 43b calculates an increase / decrease amount ΔG of the refrigerant flow rate upper limit value during a predetermined heat storage operation time (actual heat storage operation time) in order to set the calculated heat storage amount excess / deficiency ΔQ to zero. The calculated increase / decrease amount ΔG of the refrigerant flow rate upper limit value is given to the next refrigerant flow rate determining means 43c.

  This given increase / decrease amount ΔG is added to the previous refrigerant flow rate upper limit value Gmax in the next refrigerant flow rate determining means 43c, thereby correcting the previous refrigerant flow rate upper limit value Gmax, and the next refrigerant flow rate upper limit value (Gmax + ΔG). To be determined.

  And in the control apparatus 4, when performing the next heat storage operation, during the actual heat storage operation time, based on the next refrigerant flow rate upper limit (Gmax + ΔG), the opening degree of the heat storage expansion valve 31 is controlled. The refrigerant flow rate actually flowing in the refrigerant circuit is set to the refrigerant flow rate upper limit value (Gmax + ΔG). Moreover, you may control the rotation speed of the compressor 11 at this time so that a required refrigerant | coolant flow volume can be supplied to a thermal storage unit.

Specifically, when the measurement means 42 determines that the actual heat storage use operation time T is shorter than the target time T ₀ , it means that the amount of heat storage by the previous heat storage operation is small, so that ΔT The corresponding insufficient heat quantity ΔQ is obtained by the excess / deficient heat quantity estimation means 43a, the refrigerant flow upper limit value ΔG for compensating the insufficient heat quantity ΔQ is calculated by the refrigerant flow quantity calculation means 43b, and the previous refrigerant flow quantity upper limit value Gmax is set to the next time. by adding in the refrigerant flow rate decision device 43c, it is obtained to be able to bring the next thermal storage available operating time T to target time T _0.

On the other hand, when the measurement means 42 determines that the actual heat storage use operation time T is longer than the target time T ₀ , it means that the amount of heat stored by the previous heat storage operation is large. The amount ΔQ is obtained by the excess / deficient heat quantity estimation means 43a, the refrigerant flow amount upper limit value ΔG for reducing the amount of superheat ΔQ is calculated by the refrigerant flow quantity calculation means 43b, and the next refrigerant flow rate is determined as the previous refrigerant flow rate upper limit value Gmax. by adding in unit 43c, it is obtained as close to the target time T ₀ by reducing the next thermal storage available operating time T.

  According to the present embodiment, the heat storage use operation is started at a predetermined start time, and the heat storage use operation is performed until the remaining heat storage amount detected by the temperature detector 36 reaches zero. Therefore, since the remaining heat storage amount can be set to zero to prepare for the next heat storage operation, it is possible to eliminate stress exerted on the heat transfer tube of the heat storage heat exchanger 35 due to residual ice or the like. Further, in an intermediate period or the like where the cooling load is small, the upper limit value of the refrigerant flow rate is decreased, and an efficient heat storage operation in which the discount power at night is leveled can be performed.

  On the other hand, when performing the heat storage use operation using the cold heat source stored in the heat storage medium 34 in the heat storage tank 33 by the heat storage operation, the control device 4 closes the electromagnetic valves 32a and 32c and opens the electromagnetic valves 32b and 32d. Thereby, the liquid refrigerant liquefied by heat exchange in the condenser 12 flows to the heat storage heat exchanger 35 through the electromagnetic valve 32b, and is heat-exchanged with the heat storage medium 34 in the heat storage tank 33 to be in a supercooled state. Thereafter, the heat is supplied to the cooling loads 2a and 2b through the electromagnetic valve 32d.

  The end of the heat storage utilization operation is detected by the temperature detector 36. That is, if the number of cold heat sources stored in the heat storage medium 34 decreases, the temperature of the refrigerant discharged from the heat storage heat exchanger 35 increases. Therefore, the remaining amount of heat storage can be detected by detecting the temperature. In this manner, when the remaining amount of heat storage is detected, the control device 4 stops the heat storage use operation and switches to the operation of only the cooling load 2a, 2b.

In the present embodiment, the excess / deficiency heat amount ΔQ in the heat storage amount by the previous heat storage operation measures the integral value of the compressor operation capacity in the heat storage operation time t, and the compressor operation capacity in the actual heat storage use operation time T. of it may be calculated from the difference between the integral value of the compressor operating capacity (displacement) in the integral value and the target time T _0. The excess / deficiency heat amount ΔQ may be corrected according to the outside air temperature condition.

  Therefore, according to the present embodiment, the amount of stored heat can be reduced to zero each time. Therefore, in the case of an ice heat storage tank, the occurrence of stress on the heat transfer tubes of the heat storage heat exchanger due to residual ice is suppressed, and the reliability of the apparatus is reduced. Can be improved. Also, in the intermediate period when the cooling load is low, the upper limit value of the refrigerant flow rate can be reduced, and efficient heat storage operation can be carried out by leveling the discounted electricity at night so that it can be used optimally. Control can be realized.

  In addition, according to the present embodiment, the algorithm for estimating the excess or deficiency ΔQ of the heat storage amount may be about four arithmetic operations, the measurement and the sensor may be simple, and other calculations may be performed simply. This has the advantage of not requiring expensive algorithms and measurement systems.

It is a cycle system diagram which shows the structure of the thermal storage type freezing apparatus which concerns on the best form for implementing this invention. It is a block diagram which shows the detailed structure of the control apparatus in the thermal storage type freezing apparatus which concerns on the best form for implementing this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refrigerator 2a, 2b Cooling load 3 Thermal storage unit 4 Control apparatus 5,6 Refrigerant piping 11 Compressor 12 Condenser 21a, 21b Cooling expansion valve 22a, 22b Evaporator 23a, 23b Cooling solenoid valve 31 Thermal storage expansion valve 32a 32b, 32c, 32d solenoid valve,
33 heat storage tank 34 heat storage medium 35 heat storage heat exchanger 36 temperature detector 41 refrigerant flow rate upper limit control means 42 measurement means 42a heat storage use time measurement means 42b heat storage use operation target time setting means 42c calculation means 43 heat storage amount control means 43a excess Insufficient heat quantity estimation means 43b Refrigerant flow rate calculation means 43c Next refrigerant flow rate determination means

Claims (3)

A refrigerator including a compressor that compresses a gas refrigerant, a condenser that cools the gas refrigerant compressed by the compressor to form a liquid refrigerant, and a heat storage tank that is connected to the refrigerant pipe of the refrigerator and stores cold heat A cooling load connected to the refrigerant pipe of the refrigerator, a heat storage operation for supplying the liquid refrigerant to the heat storage tank, and a heat storage use operation for supplying the cold heat stored in the heat storage tank to the cooling load. Control means for switching control,
The control means obtains the heat storage use operation time until the heat storage use operation is completed at a temperature at which the heat storage use operation is started and the residual ice in the heat storage tank disappears, and is set in advance as the obtained heat storage use operation time. obtains the difference between the heat storage utilization target operation time, and estimate the excess and deficiency of the heat storage amount from the previous SL calculated difference, thermal storage to reduce the excess or deficiency in performing thermal storage operation for the next time, and a preset The upper limit value of the refrigerant flow rate of the heat storage tank that stores heat using all of the operation time is set, and the liquid refrigerant supplied to the heat storage tank is depressurized so that the refrigerant flow rate flowing through the heat storage tank becomes the set upper limit value. A regenerative refrigerating apparatus characterized by controlling the opening degree of the heat storage expansion valve and the rotational speed of the compressor .   2. The regenerative refrigerating apparatus according to claim 1, wherein the control unit corrects a heat storage amount of the next heat storage operation in accordance with a change in outside air temperature. A refrigerator comprising a compressor for compressing a gas refrigerant and a condenser for cooling the gas refrigerant compressed by the compressor to form a liquid refrigerant; and a heat storage tank for storing cold heat connected to a refrigerant pipe of the refrigerator. A cooling load connected to the refrigerant pipe of the refrigerator for cooling the object to be cooled, a heat storage operation for supplying the liquid refrigerant to the heat storage tank, and a heat storage for supplying the cold heat stored in the heat storage tank to the cooling load Control means for switching control to use operation,
The control means starts the heat storage use operation and integrates the operating capacity of the compressor before and after the end of the heat storage use operation at the time of ending the heat storage use operation based on the temperature of the cooling medium in the heat storage tank. the calculated, inferred excess or deficiency from the difference in the heat storage amount of the storage tank with the integrated value of the operating capacity of the compressor in a preset heat storage utilizing target time and the integrating value, when performing the thermal storage operation for the next time the excess or deficiency reduces, and sets the upper limit value of the refrigerant flow rate of the heat storage tank for heat storage using all the preset thermal storage operation period, the upper limit flow rate of the refrigerant flowing through the heat storage tank is set to A regenerative refrigerating apparatus characterized by controlling the opening degree of a heat storage expansion valve that depressurizes the liquid refrigerant to be supplied to the heat storage tank and the rotational speed of the compressor so as to become a value .

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