JPH04214163A - Refrigerating open showcase - Google Patents

Abstract

PURPOSE:To permit temperature control responding immediately to a temperature change in a display chamber by a method wherein air in the display chamber is sucked to a cold air circulating passage by a fan while the temperature of the sucked air is detected by a temperature sensor. CONSTITUTION:A divided chamber 20 is provided in a cold air circulating passage 4 and the divided chamber 20 is communicated with a display chamber 2 and the cold air circulating passage 4 to introduce the air in the display chamber 2 forcibly into the divided chamber 20 by a fan 23 and detect the temperature of the introduced air by a temperature sensor 19 provided in the divided chamber 20.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerated open showcase, and is an improvement in the temperature detection means for controlling the temperature inside the display room.

0002

[Prior Art] Temperature control in the display room of a refrigerated open showcase is often carried out by installing a temperature sensor in the cold air circulation path facing the cold air outlet (Japanese Patent Publication No. 1983-
57546). In addition, there is also one in which temperature sensors are provided in two locations, one in the cold air circulation path and the upper part of the display room (Japanese Patent Application Laid-Open No. 129278/1983).

0003

[Problems to be Solved by the Invention] Originally, the intended purpose of a temperature sensor was to install it in a display room and directly detect the air temperature. However, the temperature in the display room is not necessarily uniform and varies. Local temperature fluctuations may occur depending on the layout of the display room and the status of the display rooms being put in and taken out. When installing a temperature sensor, it is necessary to choose a location that does not interfere with the loading and unloading of products. In this case, the locations where it can be installed are limited to locations where air tends to stagnate, such as the back wall of the shelf, the bottom surface of the shelf board, or the top of the display room. This means that the response to heat intrusion from the outside is delayed, and furthermore, there are fewer opportunities for contact between the temperature-sensitive cylinder and the internal air, and the response of the sensor itself becomes slower. To avoid such problems, conventionally a temperature sensor was installed in the cold air circulation path, or a second temperature sensor was also installed in the exhibition room to optimize control. Response delay can be alleviated compared to when a temperature sensor is provided on the back wall of the shelf. but,
Since the temperature sensor in the cold air circulation passage detects the temperature of the circulating air, it is still not possible to accurately determine the temperature inside the display room. If the amount of heat entering from the outside increases rapidly due to loading and unloading of products, or if the internal temperature increases due to lighting of a lighting lamp, a response delay will occur. Incidentally, in order to alleviate such a delay in response, in the conventional device described above, the control state is changed in response to the switching state of the lighting switch of the lighting fixture. Especially at night, the lighting lamps are turned off and a night cover is put down in front of the display room, which makes the display room too cold and does not contribute to energy conservation.

As described above, conventionally, since the temperature inside the display room cannot be directly detected, the temperature of the display room is indirectly detected through the temperature of the circulating air in the cold air circulation passage, and fluctuation factors that cannot be addressed by this method are detected. For this, the control amount was simply corrected by separately detecting the fluctuating state.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to enable accurate and direct detection of the temperature of a display room, thereby realizing speedy and optimization of temperature control in a refrigerated open showcase at the same time.

[0006]

[Means for Solving the Problems] The present invention has a display room 2 whose front side is open, and a cold air circulation path 4 is divided along an inner circumferential wall 3 of the display room 2. In a refrigerated open showcase in which an evaporator 5 and a blower fan 6 are arranged, compartments 20 are formed inside the cold air circulation path 4, each communicating with a proper part of the display room 2 and a part of the cold air circulation path 4. A temperature sensor 19 is installed in this compartment 20 to detect the air temperature in the display room 2.
It is required that a means for forcibly introducing the air in the display room 2 into the cold air circulation path 4 via the compartment 20 is provided. A fan 23 can be used as a ventilation means for forcibly introducing the air in the display room 2 into the partition wall 20. Alternatively, an ejector effect using the flow of circulating air in the cold air circulation path 4 can be used. Specifically, an ejector wall 26 is provided inside the cold air circulation path 4 to narrow the cross-sectional area of the passage and increase the cold air passage speed. A compartment 20 is provided protruding from the peripheral wall 3 of the display room 2 and adjacent to the lower side of the ejector wall 26 in the cool air passage direction.

[0007]

[Operation] In the operating state, the air in the display room 2 is
The introduced air is forced into contact with the temperature sensor 19 arranged in the compartment 20. The reason why the air in the display room 2 is forcibly introduced in this way is to cause the air in the display room 2 to flow through the forced introduction effect and to directly detect the current temperature in the display room 2. By exposing the temperature sensor 19 to the introduced airflow, the responsiveness of the temperature sensor 19 itself is also improved.

[0008]

According to the present invention, the temperature of the introduced air is directly detected by the temperature sensor 19 while forcibly introducing air from a desired part of the display room 2 into the compartment 20 and returning it to the cold air circulation passage 4. Therefore, the current temperature inside the display room 2 can be detected accurately. As a result, temperature fluctuations in the display room 2 can be detected reliably in real time, compared to the conventional device in which a temperature sensor is provided in the cold air circulation passage 4. Therefore, for example, at night when the lighting lamps are turned off and the night cover is lowered in front of the display room 2, the inside of the display room 2 will not become too cold. It can cope well with the temperature and humidity differences between summer and winter, and it can cope well with the fact that when humidity is particularly high, the load increases and it becomes difficult to cool down.

[0009]

Embodiments (Embodiment 1) FIGS. 1 and 2 show Embodiment 1 of a refrigerated open showcase according to the present invention. In FIG. 2, the refrigerated open showcase has a display chamber 2 whose front side is open at the upper part of the case body 1, and a cold air circulation path is provided outside the inner peripheral wall 3 of the display chamber 2, surrounding the lower part, back, and upper part. 4, and an evaporator 5 and a blower fan 6 are arranged in this cold air circulation path 4. 7
11 is a display shelf provided vertically in multiple stages in the display room 2, and a lighting lamp 11.

The cold air circulation path 4 is defined between the inner circumferential wall 3 and the outer heat insulating wall 8, and has a downward outlet 9 at the front end of the upper chamber 4a and an upward outlet at the front end of the bottom chamber 4b. A suction port 10 is provided respectively. Air sucked into the bottom chamber 4b by the fan 6 through the suction port 10 is cooled while passing through the evaporator 5, and is blown out downward from the blowout port 9. This blown air cools the inside of the display room 2 while forming an air curtain in front of the opening of the display room 2, and is sucked in again from the suction port 9 and circulated.

The evaporator 5 is connected to a refrigeration unit such as a compressor 13 and a condenser 14 arranged on the side of the case body 1 and the refrigerant passage 1.
5, and the refrigerant passage 15 is provided with an electromagnetic valve 16 and an expansion valve 18 for controlling the amount of refrigerant supplied to the evaporator 5. It has a control device 17 for controlling the operating state of the solenoid valve 16 to maintain the air temperature in the display room 2 at a set temperature, and further includes a temperature sensor 1 for detecting the temperature state in the display room 2.
It has 9.

The temperature sensor 19 includes a pressure thermometer, a so-called temperature sensing cylinder 19a, in which an expansion liquid is sealed inside a thin metal tube.
It includes a signal output unit 19b that converts the pressure state of the temperature sensing cylinder 19a into an electrical signal and outputs it to the control device 17, so that fluctuations in the temperature state can be continuously detected.

In order to install the temperature sensing tube 19, a compartment 20 is provided in the cold air circulation path 4 located at the center of the back of the inner circumferential wall 3. In FIG. 1, this compartment 20 communicates with the display room 2 through an opening 3a provided in the inner circumferential wall 3, and a passage 21 of a duct led out from the compartment 20 and rising upward in the cold air circulation path 4. and a fan case 22 connected to the upper end of the passage 21, which communicates with the cold air circulation path 4. The temperature sensing cylinder 19a faces the opening 3a and is located approximately in the center of the compartment 20. A small fan 23 is arranged inside the fan case 22, and the air in the display room 2 is forcibly introduced into the compartment 20 by driving the fan 23. That is, the temperature sensing cylinder 19a can directly detect the temperature inside the display room 2 via the air introduced by the fan 23.

The control device 17 determines the control state of the solenoid valve 16 by comparing the set temperature signal set externally by the temperature setting device 24 and the output signal from the temperature sensor 19, and
Based on this determination result, an operation command signal is output to the solenoid valve 16.

In the operating state, the fan 23 is connected to the passage 21.
The air inside the display room 2 is sucked through the compartment 20 and sucked into the cold air circulation path 4. Due to this suction action, a gentle air flow separate from the air curtain is generated in the display room 2, and the air in front of the opening 3a and the air in the upper and lower spaces of the display shelf 7 are forcibly introduced into the compartment 20. . That is, air that reflects the temperature state of each part within the display room 2 is introduced into the compartment 20. Therefore, the temperature sensing tube 19a is placed in the compartment 2.
Even though the temperature is fixed within 0, the approximately average temperature state within the display room 2 can be directly detected. In addition, when products are frequently put in and taken out of a specific display shelf 7, and the amount of heat flowing into that area increases locally, or when the overall temperature state changes due to turning on or off of the illuminator lamp 11. However, this can be quickly detected and reflected in the control device 17. As shown in FIG. 1, the temperature sensing tube 19a is exposed to the airflow sucked by the fan 23, so
Its own responsiveness also improves.

In addition to the above-mentioned factors, the temperature inside the display room 2 varies greatly depending on the temperature of the surrounding environment and seasonal changes. Even in the case of such fluctuation factors, it is possible to respond without delay by accurately understanding the change in temperature within the display room 2, so there is no delay in control response. As a result, it is possible to prevent unnecessary excessive cooling, especially at night, regardless of the season.

(Embodiment 2) FIG. 3 shows a second embodiment of the present invention, which uses an ejector action that utilizes the flow action of the circulating air in the cold air circulation path 4 to remove the air in the display room 2, especially in the upper part. Air is forcibly introduced into the cold air circulation path 4. That is, the inner peripheral wall 3
An opening 3a communicating with the upper chamber 4a of the cold air circulation path 4 is provided in the upper part of the cold air circulation path 4, and the ejector wall 26 is fixed to the inner upper surface of the inner peripheral wall 3 facing the cold air circulation path 4 while covering this opening 3a. The inner peripheral wall 3 defines a compartment 20. Then, the temperature sensing tube 19a of the temperature sensor 19 is placed inside the compartment 20. The ejector wall 26 is extended from the side of the inner circumferential wall 3, narrows the passage cross-sectional area of the cold air circulation path 4, and increases the flow rate of cold air passing therethrough. This speed-increasing action reduces the pressure in the passage section divided by the ejector wall 26, so the upper air in the display chamber 2 is forcibly introduced into the compartment 20 and then into the cold air circulation path 4 through the opening 3a. .

In addition to the above, the temperature detection means including the temperature sensor 19 and the compartment 20 can be arranged at a plurality of locations facing the display room 2. The fan 23 may be a cross-flow fan or a centrifugal fan other than the axial type. A bimetal, a thermistor, or the like may be used as the temperature sensor.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional side view of essential parts showing a first embodiment of the present invention.

FIG. 2 is an overall vertical sectional side view of the showcase according to the present invention.

FIG. 3 is a longitudinal cross-sectional side view of a main part showing a second embodiment of the present invention.

[Explanation of symbols]

2 Display room 3 Inner peripheral wall 4 Cold air circulation path 5 Evaporator 6　Blower fan 17 Control device 19 Temperature sensor 19a Temperature sensing cylinder 20 Ward room 23 Fan

Claims (3)

[Claims] [Claim 1] A display room 2 with an open front is provided, and a cold air circulation path 4 is defined along an inner circumferential wall 3 of the display room 2. An evaporator 5 and a blower fan 6 are installed in the cold air circulation path 4. In the arranged open showcase, a compartment 20 is formed inside the cold air circulation path 4, and a compartment 20 is formed that communicates a proper place of the display room 2 with a part of the cold air circulation pathway 4. , a refrigerator equipped with a temperature sensor 19 for detecting the air temperature in the display room 2, and a means for forcibly introducing the air in the display room 2 into the cold air circulation path 4 through the compartment 20. open showcase. Claim 2: The air inside the display room 2 is supplied to the compartment 20 by a fan 23.
The refrigerated open showcase according to claim 1, which is installed in a refrigerator. 3. Inside the cold air circulation path 4, an ejector wall 26 that narrows the cross-sectional area of the passage and increases the cool air passage speed is protruded from the inner circumferential wall 3 of the display room 2. The refrigerated open showcase according to claim 1, wherein the compartment 20 is provided adjacently on the downstream side in the passing direction.