refrigerator

Abstract

To provide a refrigerator that comprises a cold storage material, stores and releases cold on the basis of a demand signal, and has high energy saving performance by improving the rate of cold storage and cold release.SOLUTION: A refrigerator according to the present disclosure comprises: a cooling system in which a compressor, a condenser, a pressure reducer, and an evaporator are connected in a circular pattern; a cooling chamber internally comprising the evaporator; and a cold storage material in thermal contact with the evaporator; and comprises a control part for operating the compressor on the basis of a demand signal from the outside.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a refrigerator provided with a cold storage material.

Background Art

[0002] Patent Document 1 discloses a refrigerator that is selectively operated in a normal operation mode, in which a cold storage material is provided on an inner wall surface of a storage compartment and operation is performed to maintain the temperature inside the storage compartment at a target set temperature, and a cold storage operation mode, in which the temperature inside the storage compartment is maintained at a cold storage set temperature that is lower than the target set temperature in the normal operation and lower than the freezing point of the cold storage material.

Prior Art Literature

Patent Literature

[0003]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0004] An object of the present disclosure is to provide a highly energy-efficient refrigerator using a cold storage material by increasing the speed of cold storage and cold release.

Means for Solving the Problem

[0005] The refrigerator according to the present disclosure comprises: a cooling system in which a compressor, a condenser, a pressure reducer, and an evaporator are annularly connected; a cooling chamber having the evaporator provided therein; a cold storage material in thermal contact with the evaporator; and a control unit that operates the compressor based on a demand signal from the outside.

Effects of the Invention

[0006] In this disclosure, the refrigerator, controlled by a control means, operates the compressor upon receiving a demand signal, allowing the refrigerant to be in thermal contact with the evaporator, thus enabling rapid cooling. Therefore, by allowing cooling at any time, a highly energy-efficient refrigerator can be achieved. [Brief explanation of the drawing]

[0007] [Figure 1] Cross-sectional view of a refrigerator in Embodiment 1 [Figure 2] Perspective view of the evaporator of the refrigerator in Embodiment 1 [Figure 3] Timing chart showing the temperature of each part of the refrigerator during normal cooling in Embodiment 1 [Figure 4] Timing chart showing the temperatures of each part of the refrigerator during storage and release operation in Pattern 1 of Embodiment 1. [Figure 5] Timing chart showing the temperature of each part of the refrigerator during storage and release operation in Pattern 2 of Embodiment 1. [Figure 6] Flowchart of a refrigerator in Embodiment 1 [Modes for carrying out the invention]

[0008] (Knowledge and other information that formed the basis of this disclosure) In the refrigerator industry, in addition to using the cold energy generated by the cooling cycle directly to cool the inside of the refrigerator, there have also been proposals to store cold energy using a cold storage material and use it to cool the inside of the refrigerator when the cooling cycle is not in operation.

[0009] For example, this refrigerator stores a latent heat storage material filled in a resin container inside the compartment. During normal cooling, the storage material stores cold energy (cold storage), and when the internal temperature rises due to a power outage or other reasons, the stored cold energy suppresses the rise in internal temperature (cooling).

[0010] Furthermore, power companies and other organizations employ demand response measures, which involve adjusting the amount of electricity on the demand side to balance the supply and demand for power.

[0011] Demand response is a mechanism in which an electric power company transmits a demand signal to a user in advance, and the user receives an incentive by suppressing power consumption during a certain time period.

[0012] However, in Patent Document 1, since the cold storage material is provided on the wall surface of the storage compartment, it takes time to complete cold storage even when a demand signal is received, making it difficult to obtain a sufficient cold storage effect.

[0013] The inventors considered that the lack of thermal contact between the evaporator and the cold storage material causes a time lag before the cold storage material is cooled even when the evaporator is cooled, and have conceived the subject matter of the present disclosure to solve this problem.

[0014] The present disclosure provides a refrigerator capable of rapidly performing cold storage after receiving a demand signal, in order to solve the problems of the prior art.

[0015] Hereinafter, embodiments will be described in detail with reference to the drawings. However, overly detailed description may be omitted in some cases. For example, detailed description of already well-known matters or duplicate description of substantially the same configuration may be omitted.

[0016] The accompanying drawings and the following description are provided for those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter recited in the claims.

[0017] (Embodiment 1) Hereinafter, Embodiment 1 will be described with reference to FIGS. 1 to 6.

[0018] [1-1. Configuration] In FIG. 1, a refrigerator 1 includes a heat-insulating box body 4 having an opening 2 on a front surface and a cooling compartment 3 on a back surface, and a door 5 that openably and closably closes the opening 2.

[0019] The cooling chamber 3 is provided with an evaporator 10 that constitutes a cooling system 9 in which a compressor 6, a condenser 7, and a pressure reducer 8 are connected in an annular shape, and a refrigerant such as a hydrocarbon-based gas is sealed inside the cooling system 9.

[0020] In Fig. 2, the evaporator 10 is a fin-tube heat exchanger constituted by, for example, fins 11 and pipes 12. The evaporator 10 has a configuration in which a cold storage material 13, which is a latent heat cold storage material such as a highly water-absorbent resin having a solidification temperature Tc filled in a case, is sandwiched between the fins 11, and the cold storage material 13 and the fins 11 are in thermal contact with each other.

[0021] In Fig. 1, the cooling chamber 3 is provided with a cooling fan 14 that circulates cold air generated in the cooling chamber 3 into the interior of the refrigerator 1.

[0022] A sensor 15 such as a thermistor for detecting an internal temperature is provided inside the heat-insulating box body 4.

[0023] Outside the heat-insulating box body 4, there are provided a receiving unit 16 that receives an external demand signal, and a control unit 17 that controls operations of the compressor 6 and the cooling fan 14 based on a temperature detected by the sensor 15 and a signal from the receiving unit 16.

[0024] [1-2. Operation] The operation and effect of the refrigerator 1 configured as described above will be described below.

[0025] The operation of the refrigerator 1 will be described with reference to Figs. 3 to 6.

[0026] During operation of the refrigerator 1, the high-temperature and high-pressure gas refrigerant compressed by the compressor 6 is cooled by the condenser 7 to become a low-temperature and high-pressure liquid refrigerant, flows to the pressure reducer 8, is depressurized to become a low-temperature and low-pressure gas-liquid two-phase flow, and flows to the evaporator 10.

[0027] Then, due to the temperature difference between the evaporator 10 and the surrounding air, the liquid refrigerant vaporizes, absorbs heat from the surroundings by the heat of vaporization to evaporate and generate cold air, becomes a low-temperature and low-pressure gaseous refrigerant, and is sucked into the compressor 6 again.

[0028] The detailed operation will be explained below, divided into normal cooling operation and storage / release cooling operation when a demand signal is received.

[0029] First, the normal cooling operation will be explained using Figure 3. During normal cooling operation, the control unit 17 starts the compressor 6 and cooling fan 14 when the temperature detected by the sensor 15 rises above the ON temperature, for example, Tr2 = 7°C (t1, t3, t5), in order to maintain the inside of the insulated box 4 in a refrigerated temperature range of, for example, approximately 5°C, and stops the compressor 6 and cooling fan 14 when it falls below the OFF temperature, for example, Tr1 = 3°C (t2, t4).

[0030] During this time, the cold storage material 13 remains in a solidified state and is not allowed to cool.

[0031] Next, the storage and cooling operation will be explained using Figures 4 and 5.

[0032] [Pattern 1] When a demand signal is received from the power company while the compressor 6 is operating (t6), operation continues and a cooling storage operation is performed. During the cooling storage operation, liquid refrigerant flows into the evaporator 10 and evaporates, transferring cold energy from the refrigerant to the pipes 12 and fins 11, and the cooling material 13 is cooled.

[0033] When the time (t7) received by the demand signal arrives, the control unit 17 stops the compressor 6 and operates the cooling fan 14, allowing the cold storage material 13 to exchange heat with the inside of the refrigerator 1 via the fins 11, thereby cooling the inside of the refrigerator without using the power to operate the compressor 6.

[0034] Then, when the temperature detected by sensor 15 becomes Tr2 or higher (t8), the compressor 6 is started, and normal cooling operation begins.

[0035] [Pattern 2] When a demand signal is received from the power company while the compressor 6 is stopped (t9), the compressor 6 is started and a thermal storage operation is performed. During the thermal storage operation, liquid refrigerant flows into the evaporator 10 and evaporates, transferring cold energy from the refrigerant to the pipes 12 and fins 11, and the thermal storage material 13 is cooled.

[0036] When the time (t10) received by the demand signal arrives, the control unit 17 stops the compressor 6 and operates the cooling fan 14. This allows the cold storage material 13 to exchange heat with the inside of the refrigerator 1 via the fins 11, thus cooling the inside of the refrigerator without using the power to operate the compressor 6. At this time, the solidification temperature Tc of the cold storage material 13 is between Tr1 and Tr2, and acts to maintain the internal temperature between Tr1 and Tr2.

[0037] Then, when the temperature of sensor 15 rises above Tr2 (t11), the compressor 6 is started, and normal cooling operation begins.

[0038] The above-mentioned normal cooling operation and storage / discharging operation will be explained in detail using Figure 6.

[0039] When the refrigerator operation is started, in step S1, the control unit 17 first determines whether or not a demand signal has been received by the receiving unit 16. If a signal has been received, the process moves to step S2 to start the storage and release cooling operation; otherwise, the process moves to step S8 to start the normal cooling operation.

[0040] [Normal cooling operation] During normal cooling operation, in step S9, the control unit 17 first checks with the sensor 15 to see if the temperature inside the chamber is higher than Tr2. If it is lower, the process in step S9 is repeated; if it is higher, the process proceeds to step S10.

[0041] In step S10, the cooling operation is started, and the control unit 17 operates the compressor 6 and the cooling fan 14, then proceeds to step S11.

[0042] In step S11, the control unit 17 determines whether it has received a demand signal from the receiving unit 16. If it has received a signal, it proceeds to step S2 to start the storage and release cooling operation; otherwise, it proceeds to step S12.

[0043] In step S12, the control unit 17 compares the temperature inside the chamber with that of the sensor 15 to determine if it is lower than Tr1. If it is higher, the process in step S12 is repeated; otherwise, the process proceeds to step S13, where the control unit 17 stops the compressor 6 and the cooling fan 14.

[0044] [Storage and cooling operation] During storage and cooling operation, in step S3, the control unit 17 operates the compressor 6 and the cooling fan 14, and then proceeds to step S4.

[0045] In step S4, the control unit 17 uses the sensor 15 to compare whether the temperature inside the chamber is lower than Tr1. If it is higher, the process in step S4 is repeated; otherwise, the process proceeds to step S5. At this time, since the solidification temperature Tc of the cold storage material 13 is set higher than Tr1, the cold storage material 13 has solidified, and the latent heat of fusion can be utilized in the cooling operation described later, allowing for high-efficiency cooling.

[0046] In step S5, the control unit 17 determines whether the demand time set when the demand signal was received has arrived. If it has not arrived, the process in step S5 is repeated. If it has arrived, the process proceeds to step S6 and the cooling operation begins.

[0047] In step S6, the cooling operation begins, the compressor 6 is stopped, the cooling fan 14 continues to operate, and the process proceeds to step S7.

[0048] During cooling operation, the cooling capacity of the thermal storage material 13 is lower than the cooling capacity of the compressor 6. Therefore, the temperature inside the chamber decreases in the initial stages of operation, but then gradually rises.

[0049] Then, in step S7, the control unit 17 compares the temperature inside the chamber with that of the sensor 15 to see if it is higher than Tr2. If it is lower, the process in step S7 is repeated; if it is higher, the cooling operation is terminated and the system transitions to normal cooling operation (S10).

[0050] [1-3. Effects, etc.] As described above, in this embodiment, the refrigerator 1 comprises a cooling system 9 in which a compressor 6, a condenser 7, a pressure reducer 8, and an evaporator 10 are connected in a ring, a cooling chamber 3 with an evaporator 10 inside, a thermal storage material 13 in thermal contact with the evaporator 10, and a control unit 17 that operates the compressor 6 based on an external demand signal.

[0051] This allows the control unit 17 to synchronize the demand signal with the cooling operation of the compressor 6. As a result, cooling can be quickly performed in response to the demand signal, and cooling can be reliably released at the time set by the demand response, thereby improving the effectiveness of cooling.

[0052] Furthermore, in this embodiment, the refrigerator 1 is equipped with a cooling fan 14 that circulates the cold air generated by the evaporator 10 into the storage compartment.

[0053] This allows the cooling fan 14 to forcibly exchange heat between the cold stored in the thermal storage material 13 and the air in the storage chamber. Therefore, at the time set by the demand response, the cooling fan 14 can transfer the cold stored in the thermal storage material 13 into the storage chamber, improving the cooling effect.

[0054] Furthermore, in this embodiment, the refrigerator 1 is characterized in that, when it receives a demand signal, the control unit 17 starts operating the compressor 6. This allows the compressor 6 to be operated when a demand signal is received, enabling rapid cooling of the thermal storage material 13. As a result, cooling can be achieved even more quickly in response to the demand signal, and the cooling can be reliably released at the time set by the demand response, further improving the effectiveness of the cooling system.

[0055] Furthermore, in this embodiment, the refrigerator 1 is characterized in that, when a time set based on the demand signal arrives, the control unit 17 stops the compressor 6 and starts operating the cooling fan 14.

[0056] This allows the cooling fan 14 to forcibly exchange heat between the cold stored in the thermal storage material 13 and the air in the storage chamber at the time set by the demand signal. As a result, the cooling fan 14 can quickly transfer the cold from the thermal storage material 13 into the storage chamber, further improving the cooling effect.

[0057] (Other embodiments) As described above, Embodiments 1 and 2 have been explained as examples of the technology disclosed in this application. However, the technology in this disclosure is not limited thereto and can also be applied to embodiments that have been modified, replaced, added, or omitted.

[0058] Therefore, other embodiments are illustrated below.

[0059] In this embodiment 1, the refrigerator 1 was described as having one storage compartment, but even if there are two or more storage compartments, the same effect can be obtained as long as the refrigerator is equipped with an evaporator 10 and a cooling fan 14 that are in thermal contact with the cold storage material 13, and the compressor 6 and the cooling fan 14 are controlled by the control unit 17.

[0060] Furthermore, although this embodiment describes a configuration in which the demand signal is received by the receiving unit 16, it is also possible to have a switch for inputting the demand signal, and to switch the control by turning the switch on or off.

[0061] Furthermore, although this embodiment describes the refrigerator with only one storage compartment and focuses on the refrigeration temperature range, similar effects can be obtained in a refrigerator equipped with multiple storage compartments with different temperature ranges, where the temperature of the storage compartments is controlled to remain constant by means of airflow switching such as dampers, by providing a cold storage material in the evaporator.

[0062] Furthermore, a refrigerator equipped with multiple storage chambers at different temperature zones may be configured with multiple evaporators. In this case, the cold storage material is placed in the evaporator that cools the storage chambers at refrigeration temperature zones, and when a demand signal is received, the control unit operates the compressor and controls the flow of refrigerant to the evaporator equipped with the cold storage material, thereby enabling efficient cold storage operation.

[0063] Furthermore, in this embodiment, the evaporator is a fin-tube type heat exchanger composed of multiple fins and pipes, with the thermal storage material sandwiched between the fins. However, by, for example, using a microchannel heat exchanger composed of flat tubes with multiple flow paths and fins, and sandwiching the thermal storage material between the pipes, the contact area between the thermal storage material and the pipes can be increased, thereby improving the thermal storage and release effect.

[0064] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents. [Industrial applicability]

[0065] This disclosure describes a system that stores cold energy using a thermal storage material that exchanges heat with an evaporator, and can be used at any time in response to a demand signal, making it applicable to various types and sizes of refrigerators, including those for home and commercial use. [Explanation of Symbols]

[0066] 1. Refrigerator 3 Cooling room 6. Compressor 7. Condenser 8. Pressure reducer 9. Cooling System 10 Evaporator 13 Cold storage material 14 Cooling fan 17 Control Unit

Claims

1. A cooling system in which a compressor, condenser, pressure reducer, and evaporator are connected in a ring shape, A cooling chamber equipped with the aforementioned evaporator inside, The evaporator is equipped with a thermally contacting thermal storage material, The system includes a control unit that operates the compressor based on an external demand signal, Regarding the storage and release cooling operation when the aforementioned demand signal is received, When the compressor receives the demand signal during operation, it continues operation and performs a cooling operation. When the demand signal is received while the compressor is stopped, a cooling operation is performed to start the compressor. The evaporator comprises fins and pipes, A refrigerator characterized by sandwiching the aforementioned cold storage material between the fins.

2. The refrigerator according to claim 1, characterized in that it is equipped with a cooling fan in the storage chamber that circulates the cold air generated by the evaporator into the storage chamber.

3. The refrigerator according to claim 2, characterized in that when a time set based on the demand signal is reached, the control unit stops the compressor and operates the cooling fan.

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