JPH06159871A - Absorption type refrigerating machine - Google Patents

Abstract

PURPOSE:To furnish an absorption type refrigerating machine which makes it possible to detect occurrence of abnormality in an evaporator or an absorber and to give information on it at a low cost. CONSTITUTION:A pressure difference between an inlet and an outlet of cold water passing an evaporator 1 is measured by cold water pressure detectors S1 and S2, and a flow rate of the cold water at the current time point is calculated from this pressure difference and the relationship between the flow rate of the cold water and the pressure difference stored beforehand. When the flow rate of the cold water thus calculated becomes a prescribed flow rate or below, a signal is outputted from an abnormality detecting device 40 and thereby an alarm device 41 is made to operate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an absorption refrigerator, and more particularly to an absorption refrigerator capable of detecting an abnormality in an evaporator or a condenser.

[0002]

2. Description of the Related Art A flow meter is installed in a cold water path or a cooling water path to measure the flow rate of the cold water or the cooling water.
There is a technology to monitor insufficient cooling water flow rate, adhesion of scale in the cooling water system, chilled water pump or abnormality of chilled water pump.

[0003]

However, a flow meter with high accuracy is expensive, and there is a problem that using such a high-performance flow meter causes a high equipment cost, which is low in cost. It has been desired to develop a technique capable of accurately detecting the flow rate of cold water or cooling water and monitoring abnormality in the evaporator or absorber.

[0004]

As a concrete means for solving the above-mentioned problems of the prior art, the present invention is constituted by connecting a regenerator, a condenser, an evaporator, an absorber, a heat exchanger and the like by piping. An absorption chiller that measures the pressure difference between the inlet and outlet of cold water that passes through the evaporator, and calculates the current cold water flow rate from this pressure difference and the relationship between the stored cold water flow rate and pressure difference. However, when this chilled water flow rate becomes equal to or less than a predetermined flow rate, an absorption refrigerator having an alarm means for outputting an alarm,

An absorption type refrigerating machine comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger and the like connected by pipes, which is an inlet / condenser of cooling water passing through the absorber and the condenser. The pressure difference between the outlets is measured, and the current cooling water flow rate is calculated from this pressure difference and the relationship between the cooling water flow rate and the pressure difference stored in advance, and this cooling water flow rate becomes equal to or lower than the first predetermined flow rate. And a warning unit that outputs a first alarm when the cooling water flow rate becomes less than or equal to a second predetermined flow rate that is less than the first predetermined flow rate. Absorption type refrigerator

[0006] An absorption refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger and the like connected by piping, wherein the flow rate of cold water passing through the evaporator and the inlet / outlet of the evaporator are When the current cooling water flow rate is calculated based on the cold water temperature and the cooling water temperature at the absorber inlet / condenser outlet of the cooling water that passes through the absorber and condenser, and when this cooling water flow rate falls below the specified flow rate By providing an absorption refrigerating machine characterized by comprising alarm means for outputting an alarm, the above-mentioned problems of the prior art are solved.

[0007]

The cost can be reduced because an inexpensive pressure gauge is used, or a pressure gauge and a thermometer are used together to determine the flow rate of cold water or cooling water and the abnormality of the evaporator or the absorber is monitored.

[0008]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
It will be described in detail based on. FIG. 1 is a schematic configuration diagram of an absorption chiller-heater which is an absorption refrigerator using water as a refrigerant and lithium bromide (LiBr) solution as an absorption liquid (solution),
1 is an evaporator, 2 is an absorber, 3 is an evaporator 1 and an absorber 2
An evaporator absorber cylinder 4 in which is housed 4 is a high temperature regenerator heated by a high temperature heat source such as a gas burner 5, 6 is a low temperature regenerator, 7 is a condenser, 8 is a low temperature regenerator 6 and a condenser 7
A low-temperature regenerator condenser barrel containing 9 is a solution heat for exchanging heat between a low-concentration absorption liquid flowing from the absorber 2 to the high-temperature regenerator 4 and a high-concentration absorption liquid flowing from the low-temperature regenerator 6 to the absorber 2. The low-temperature heat exchanger 10 serving as an exchanger stores a rare absorption liquid flowing from the absorber 2 to the high-temperature regenerator 4 via the low-temperature heat exchanger 9 and an intermediate-concentration absorption liquid flowing from the high-temperature regenerator 4 to the low-temperature regenerator 6. High temperature heat exchangers 11 to 11 which are solution heat exchangers for heat exchange
Reference numeral 15 is an absorption liquid pipe, 16 is an absorption liquid pump, and 17 and 1
8 is a refrigerant pipe, 19 is a refrigerant circulation pipe, 20 is a refrigerant pump, 21 is a gas pipe connected to the gas burner 5, 22 is a heating amount control valve, and 23 is cold water pipe in which an evaporator heat exchanger 24 is provided in the middle. , 25 are cooling water pipes provided with a cooling water pump 26, an absorber heat exchanger 27, and a condenser heat exchanger 28 on the way, and they are connected by pipes as shown in FIG.

Further, 29 is a refrigerant bypass pipe for connecting the refrigerant reservoir 30 of the evaporator 1 and the absorbing liquid reservoir 31 of the absorber 2 to each other, 32 is an opening / closing valve, and 33 is connecting the absorbing liquid pipe 12 and the absorber 2. Absorbing liquid bypass pipe, 34 is an opening / closing valve, 35 is a refrigerant vapor bypass pipe connecting the refrigerant pipe 17 and the absorber 2, 36 is an opening / closing valve, and 37 is the absorbing liquid pipe 11 and the absorbing liquid bypass pipe 33. A bypass pipe for connection, a bypass pipe for connecting the low temperature regenerator 6 and the absorber 2 and a bypass pipe for connecting the absorbing liquid pipe 11 and the bypass pipe 38 are connected to each other as shown in FIG. Open / close valve 32.
34 and 36 are closed when cold water is supplied and open when hot water is supplied.

S1 and S2 are installed at the inlet side and outlet side pressures of the evaporator 1 of the cold water pipe 23, and the pressure P of each portion is set.
This is a cold water pressure detector that detects 1.P2.

Reference numeral 40 is an abnormality detecting device for detecting an abnormality of the evaporator 1 by inputting a pressure signal from the cold water pressure detectors S1 and S2. The abnormality detecting device 40 is, for example, a control panel ( (Not shown), and is composed of a microcomputer. Further, 41 is the abnormality detection device 4
The alarm device is provided on the control panel similarly to 0 and operates by receiving a signal from the abnormality detection device 40. The alarm device 41 includes a display device 42 having a plurality of segment elements and a buzzer 43, for example. Then, the display device 42 blinks, for example, the characters ALARM based on the signal from the abnormality detection device 40.

The configuration of the abnormality detecting device 40 will be described below with reference to FIG. Reference numeral 44 denotes an input interface for inputting a pressure signal from the cold water pressure detectors S1 and S2, converting the signal, and outputting the signal to a central processing unit (hereinafter referred to as CPU) 45. Reference numeral 46 stores a predetermined calculation program and the like. A storage device (hereinafter referred to as ROM), 47 is an output interface for inputting a signal from the CPU 45 and outputting it to the alarm device 41, 48 is a signal generator (hereinafter referred to as CLOCK) that outputs a signal at predetermined time intervals, and 49 is each cold water. It is a readable / erasable storage device (hereinafter referred to as RAM) that stores the pressure detected by the pressure detector.

The ROM 46 has a chilled water pressure detector S1.
・ Pressure difference ΔP ₁₂ from cold water pressures P1 and P2 detected by S2
Equation (ΔP ₁₂ = P 1 -P 2) for calculating the pressure difference ΔP
₁₂ and the cold water flow rate (%) flowing through the cold water pipe 23 (for example, the relationship of FIG. 3) and the cold water flow rate, the evaporator 1
The determination criteria for determining the state of are stored.

In FIG. 3, cold water pressure detectors S1 and S are shown.
If the pressure difference ΔP ₁₂ between the cold water pressures P1 and P2 detected by 2 is 1.5 mAq or more, the cold water flow rate is 60% of the standard.
Since the above is secured and the cooling operation or the like functions without any problem, this state is set as the region A; normal state, and the pressure difference ΔP is set.
_{If 12} is between 0.8 and 1.5 mAq, for example, the chilled water flow rate is 40 to 60% of the standard, and there is some abnormality, but it is not enough to determine that operation is impossible. When the pressure difference ΔP ₁₂ becomes 0.8 mAq or less, for example, the cold water flow rate can be secured to 40% or less of the standard, and therefore cold water cannot be supplied in a normal state. This state is classified as area C; abnormal state.

During the cold water supply operation of the absorption chiller-heater, the refrigerant evaporated in the high temperature regenerator 4 flows to the condenser 7 via the low temperature regenerator 6 as in the conventional absorption chiller, and then the condenser heat exchanger. After exchanging heat with the cooling water flowing through 28 to condense, it flows to the evaporator 1 through the refrigerant pipe 18. The refrigerant exchanges heat with the water flowing through the evaporator heat exchanger 24 to evaporate, and the water flowing through the evaporator heat exchanger 24 is cooled by the heat of vaporization. Then, cold water circulates through the load. Further, the refrigerant evaporated in the evaporator 1 is absorbed by the absorbing liquid in the absorber 2. The dilute absorption liquid that has absorbed the refrigerant and becomes thin in concentration is sent to the high temperature regenerator 4 through the low temperature heat exchanger 9 and the high temperature heat exchanger 10 by the operation of the absorption liquid pump 16. The absorbing liquid sent to the high temperature regenerator 4 is heated by the burner 5 to evaporate the refrigerant, and the medium concentration absorbing liquid flows to the low temperature regeneration 6 through the high temperature heat exchanger 10. In the low temperature regenerator 6, the absorbing liquid is heated by the refrigerant vapor flowing from the high temperature regenerator 10 through the refrigerant pipe 17, and the refrigerant vapor is further separated to have a high concentration. The absorbing liquid having a high concentration is cooled by the low temperature heat exchanger 9 and is sent to the absorber 2 to be dispersed.

As described above, the abnormality detection when the absorption chiller-heater is operating will be described with reference to the flowchart of FIG.

The cold water pressures P1 and P2 detected by the cold water pressure detectors S1 and S2 are the input interfaces 44 and C, respectively.
It is temporarily stored in the RAM 49 via the PU 45.

Next, on the basis of the signal from the CLOCK 48, the cold water pressures P1 and P2 stored in the RAM 49 are read into the CPU 45 at predetermined time intervals, and the ROM 45 is read.
From 46, the arithmetic expression for obtaining the pressure difference ΔP ₁₂ and the relational expression of FIG. 3 are read, and the CPU 45 reads the pressure difference ΔP ₁₂
And the cold water flow rate (%) are calculated.

Then, the state determination of the evaporator 1 based on the flow rate of cold water is performed based on the region determination defined in FIG. For example, the cold water pressure P1 on the inlet side is, for example, 0.8 kgf / cm.
² , assuming that the cold water pressure P2 on the outlet side is 0.6 kgf / cm ² , the pressure difference ΔP ₁₂ is 2 mAq, and the cold water flow rate at this time is calculated to be 70%, which is located in the area A (normal). Is determined. Therefore, in this case, the CPU 4
5 does not output an abnormal signal.

However, the cold water pressure P1 is, for example, 0.65 k.
If the gf / cm ² and the cold water pressure P2 are 0.6 kgf / cm ² , the pressure difference ΔP ₁₂ is 0.5 mAq, and the cold water flow rate at this time is calculated to be 30%, which is located in the region C (abnormal). It is determined that In this case, the CPU 45 outputs an abnormal signal through the output interface 47. That is, A is displayed on the display device 42 of the abnormality detection device 41.
The character of LARM is made to blink, the buzzer 43 is sounded, and at the same time, the operation of the absorption chiller-heater is stopped.

The cold water pressure P1 is, for example, 0.72 kg.
If f / cm ² and the cold water pressure P2 are 0.6 kgf / cm ² , the pressure difference ΔP ₁₂ is 1.2 mAq, and the cold water flow rate at this time is calculated to be 50%, which is located in the region B (somewhat abnormal). It is determined that And in this case, the CPU 45
Outputs a slightly abnormal signal to the alarm device 41, causes the display device 42 to blink the ALARM character to call the attention of the administrator, and prompts an early inspection (the operation of the absorption chiller / heater is not stopped).

In the above embodiment, the description has been given based on the absorption type chiller-heater capable of supplying cold water or hot water. However, even in the absorption chiller-heater supplying only chilled water, the abnormality detecting device is provided similarly to the above embodiment. As a result, the same operational effect can be obtained.

According to the above-described embodiment, it is possible to easily detect an abnormal flow rate of cold water or hot water due to a failure of a cold water pump (not shown), so that maintenance and inspection of the absorption chiller water heater can be performed in a timely manner. Moreover, cost reduction can be achieved.

(Embodiment 2) A second embodiment of the present invention is shown in FIG.
~ It demonstrates based on FIG. It should be noted that configurations that are not particularly described are omitted because they are similar to those of the first embodiment.

In FIG. 5, S3 and S4 are installed on the inlet side of the absorber 2 of the cooling water pipe 25 and the outlet side of the condenser 7, and are cooling water pressure detectors for detecting the pressures P3 and P4 at the respective portions. The pressure signal from each pressure detector is input to the abnormality detecting device 40, the cooling water flow rate is calculated by this abnormality detecting device as in the first embodiment, and the cooling water flow rate thus obtained is set to a predetermined value. Compared with the value, it outputs a little abnormality and an alarm of abnormality.

FIG. 6 shows the pressure difference Δ between the cooling water pressures P3 and P4.
FIG. 7 is an example of a relational expression between P ₃₄ (P3-P4) and the cooling water flow rate (%), and FIG. 7 is an example of control, and the absorber 2 and the condenser 7 are controlled in the same manner as in Example 1. Abnormality of flowing cooling water flow path is detected

According to the above-described embodiment, it is possible to easily detect an abnormal flow rate of cold water or hot water due to a failure of the cooling water pump 26, and to notify the abnormal state in two stages. The administrator can be informed briefly about the flow rate status, and maintenance and inspection of the absorption chiller-heater can be performed in a timely manner, and the cost can be reduced.

(Embodiment 3) A third embodiment of the present invention is shown in FIG.
It will be described based on. It should be noted that configurations that are not particularly described are omitted because they are similar to those of the first embodiment.

In the apparatus of the third embodiment, the above-mentioned first embodiment is used.
Together with the cold water pressure detectors S1 and S2 used in the above, the cold water temperature detectors S5 and S6 for detecting the cold water temperatures T5 and T6 at the inlet side and the outlet side of the evaporator 1, the inlet side of the absorber 2 and the condenser. The cooling water temperature detectors S7 and S8 for detecting the cooling water temperatures T7 and T8 on the 7 outlet side are installed.

The heat balance of the double-effect absorption chiller-heater shown in FIG. 8 has a heat input Q _E from the cold water system and a heat input Q from the regenerator.
_G , where the heat output to the cooling water system is Q _{A + C} , Q _E + Q _G = Q _{A + C} , and Q _E = V _E × ΔT _E (V _E ; cold water system flow rate, ΔT _E ; cold water system temperature _{difference) Q G = V E × ΔT} E × (1 / COP) (COP; coefficient of _{performance) Q A + C = V C} × ΔT C (V C; cooling water flow rate, [Delta] T _C;
Cooling water system temperature difference), so V _E × ΔT _E + V _E × ΔT _E × (1 / COP) = V _C ×
It can be rewritten as ΔT _C. Then, from this, V _C can be transformed into V _C = {V _E × ΔT _E (1 + 1 / COP)} / ΔT _C , and the internal COP of the cooling water refrigerator can be changed.
Is substantially constant (for example, 1.2), the flow rate V _C of the cooling water system can be calculated by calculation if the flow rate and temperature difference of the cooling water system and the temperature difference of the cooling water system are known.

In the abnormality detecting device 40 of this embodiment, it is determined that the operation formula for obtaining the cooling water flow rate V _C with COP = 1.2 and that the obtained cooling water flow rate V _C is 60% or more is normal. , 40 to 60%, it is determined that there is some abnormality, and when it is 40% or less, the determination criteria to determine that there is abnormality is stored in the ROM 46.
45 does not output an abnormal signal, and when it is slightly abnormal, the CPU 45 causes the display device 42 to blink the ALARM character via the output interface 47, and outputs a slightly abnormal signal to the alarm device 41, and when it is abnormal, the output interface 47. The CPU 45 causes the display device 42 to blink the character ALARM and outputs an abnormal signal for sounding the buzzer 43 to the alarm device 41, and at the same time, a signal for stopping the operation of the absorption chiller-heater is output via the CPU 45. There is.

For example, the rated cold water flow rate of an absorption chiller-heater of 100 RT is 60.5 m ³ / hr, and the cold water pressure P1
Is 0.8 kgf / cm ² and P2 is 0.6 kgf / cm ^2.
Cold water flow rate is 70%, cold water temperature T5 is 10 ° C, T6 is 7
C, the cooling water temperature T7 is 32 ° C., and T8 is 35.3 ° C., the cooling water flow rate V _{C in the} CPU 45 is about 117% (7
0.6 m ³ / hr), which is determined to be normal.

However, the cold water pressure P1 is 0.68 kgf.
/ Cm ² , P2 is 0.6 kgf / cm ² , cold water temperature T5
Is 10 ° C, T6 is 7 ° C, cooling water temperature T7 is 32 ° C, T8
Is 36.5 ° C., the cooling water flow rate V _C is calculated to be approximately 49%, it is determined to be somewhat abnormal, and the character ALARM is blinked on the display device 42.

The cold water pressure P1 is 0.68 kgf / c.
m ² , P2 is 0.6 kgf / cm ² , cold water temperature T5 is 1
0 ℃, T6 is 7 ℃, cooling water temperature T7 is 32 ℃, T8 is 3
At 8 ° C., the cooling water flow rate V _C was calculated to be approximately 37%,
Since it is determined to be abnormal, the character ALARM is caused to blink on the display device 42 and the buzzer 43 is sounded, and at the same time, the operation of the absorption chiller-heater is stopped.

The cooling water pump 26 is also used in the above embodiment.
It is possible to easily detect abnormalities in the flow rate of cold or hot water due to a malfunction of the, etc., which enables timely maintenance and inspection of the absorption chiller-hot water machine, and also enables cost reduction.

Since the present invention is not limited to the above-described embodiments, various modifications can be made without departing from the spirit of the claims.

For example, the flow rate of cold water in FIG. 3 and the flow rate of cooling water in FIG. 6 may be divided into two regions, normal and abnormal.

The cold water pressure detectors S1 and S2, etc.
It is possible to use a differential pressure gauge or the like that can directly detect the pressure difference.

[0039]

As described above, according to the present invention, the regenerator
An absorption refrigerating machine configured by connecting a condenser, an evaporator, an absorber, a heat exchanger, etc. with piping, measuring a pressure difference between an inlet and an outlet of cold water passing through the evaporator, and the pressure difference, Absorption-type refrigeration characterized by comprising alarm means for calculating a current cold water flow rate from a relationship between a cold water flow rate and a pressure difference stored in advance and outputting an alarm when the cold water flow rate falls below a predetermined flow rate. Machine,

An absorption type refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger and the like connected by pipes, which is an inlet / condenser of cooling water passing through the absorber and the condenser. The pressure difference between the outlets is measured, and the current cooling water flow rate is calculated from this pressure difference and the relationship between the cooling water flow rate and the pressure difference stored in advance, and this cooling water flow rate becomes equal to or lower than the first predetermined flow rate. And a warning unit that outputs a first alarm when the cooling water flow rate becomes less than or equal to a second predetermined flow rate that is less than the first predetermined flow rate. Is an absorption chiller that

An absorption refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger and the like connected by piping, wherein the flow rate of cold water passing through the evaporator and the inlet / outlet of the evaporator are Calculate the current cooling water flow rate based on the cold water temperature and the cooling water temperature at the absorber inlet / condenser outlet of the cooling water that passes through the absorber and condenser, and when this cooling water flow rate falls below the specified flow rate. Since the absorption refrigerating machine is equipped with an alarm means for outputting an alarm,

Even when the cold water or the flow rate of the cooling water is reduced, the cost can be significantly reduced while maintaining the accuracy of the abnormality detection, and the remarkable effect is achieved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a device configuration of a first embodiment.

FIG. 2 is an explanatory diagram showing a configuration of an alarm unit according to the first embodiment.

FIG. 3 is an explanatory diagram showing the relationship between cold water pressure and cold water flow rate in the first embodiment.

FIG. 4 is an explanatory diagram showing a control flow of the first embodiment.

FIG. 5 is an explanatory diagram showing a device configuration of a second embodiment.

FIG. 6 is an explanatory diagram showing the relationship between the cooling water pressure and the cooling water flow rate according to the second embodiment.

FIG. 7 is an explanatory diagram showing a control flow of the second embodiment.

FIG. 8 is an explanatory diagram showing a device configuration of a third embodiment.

[Explanation of symbols]

 1 Evaporator 2 Absorber 3 Evaporator Absorber cylinder 4 High temperature regenerator 5 Gas burner 6 Low temperature regenerator 7 Condenser 8 Low temperature regenerator Condenser cylinder 9 Low temperature heat exchanger 10 High temperature heat exchanger 11, 12, 13, 14・ 15 Absorbing liquid piping 16 Absorbing liquid pump 17 ・ 18 Refrigerant piping 19 Refrigerant circulating piping 20 Refrigerant pump 21 Gas piping 22 Heating amount control valve 23 Cold water piping 24 Evaporator heat exchanger 25 Cooling water piping 26 Cooling water pump 27 Absorber heat Exchanger 28 Condenser heat exchanger 29 Refrigerant bypass pipe 30 Refrigerant pool 31 Refrigerant reservoir 31 Absorbing liquid reservoir 32 Open / close valve 33 Absorbing liquid bypass pipe 34 Open / close valve 35 Refrigerant vapor bypass pipe 36 Open / close valve 37/38/39 Bypass pipe 40 Abnormality detector 41 Alarm device 42 Display device 43 Buzzer 44 Input interface 45 Central processing unit (CPU) 46 Storage device ( OM) 47 Output interface 48 Signal generator (CLOCK) 49 Storage device (RAM) S1 / S2 Cold water pressure detector S3 / S4 Cooling water pressure detector S5 / S6 Cold water temperature detector S7 / S8 Cooling water temperature detector A ( Normal area B (somewhat abnormal) area C (abnormal) area

Front page continuation (72) Inventor Kazuhiro Yoshii 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (72) Inventor Tetsuro Kishimoto 2-18 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. Within

Claims (3)

[Claims] 1. An absorption refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger, etc., which are connected by pipes, wherein the pressure difference between the inlet / outlet of cold water passing through the evaporator is Equipped with alarm means for measuring, calculating the current cold water flow rate from the relationship between this pressure difference and the previously stored cold water flow rate and pressure difference, and outputting an alarm when this cold water flow rate falls below a predetermined flow rate. An absorption chiller characterized by that. 2. An absorption refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger, and the like, which are connected to each other by pipes, wherein an inlet / outlet of cooling water passing through the absorber and the condenser. The pressure difference between the condenser outlets is measured, and the current cooling water flow rate is calculated from this pressure difference and the relationship between the cooling water flow rate and the pressure difference stored in advance, and this cooling water flow rate is the first predetermined flow rate. A warning means is provided for outputting a first warning when the temperature becomes below and a second warning when the cooling water flow rate becomes less than or equal to a second predetermined flow rate that is less than the first predetermined flow rate. A characteristic absorption refrigerator. 3. An absorption refrigerator comprising a regenerator, a condenser, an evaporator, an absorber, a heat exchanger, etc., which are connected by piping, wherein the flow rate of cold water passing through the evaporator and the inlet / outlet of the evaporator. The cooling water flow rate at the present time is calculated based on the cooling water temperature of the section and the cooling water temperature at the inlet / condenser outlet of the cooling water that passes through the absorber and the condenser. An absorption chiller, which is equipped with an alarm means for outputting an alarm when the temperature rises.