JP3608655B2 - Refrigeration capacity test method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention arranges a heater downstream of the cooler and adjusts the input power of the heater so that the decrease in the sensible heat of the air cooled by the cooler and the increase in the sensible heat of the air heated by the heater are balanced, The present invention relates to a refrigeration capacity test method and apparatus for estimating the refrigeration capacity of a cooler with an input power that matches the refrigeration capacity.
[0002]
[Prior art]
Refrigerated warehouses are used for the purpose of cooling or freezing foods. In some cases, the refrigeration capacity is estimated based on a test method that establishes a standard condition for finding the practical capacity of the refrigeration apparatus attached to the refrigerated warehouse. The refrigeration capacity is generally the amount of heat that the refrigeration apparatus absorbs from the object to be frozen per unit time. If this value is large, the refrigeration capacity is higher.
[0003]
Conventionally, methods that have been considered desirable for measuring the refrigeration capacity of refrigeration systems include: The first method is to provide an inspection room surrounded by double heat insulation walls, and to control the power input to the heater so that the temperature of the air in the inspection room is eliminated by arranging a cooler and a heater in the inspection room. The refrigerating capacity is estimated with the input power balanced with the refrigerating capacity (JIS-B-8626 refrigeration unit cooler refrigerating capacity test method).
[0004]
This is based on the premise that the thermal equilibrium condition is established in the examination room, and it takes an infinite time to establish the equilibrium condition, and a long time must be taken to obtain the measurement value.
[0005]
Further, the second method estimates the refrigeration capacity based on the product of the temperature difference of the air at the inlet / outlet of the cooler and the mass flow rate and specific heat of the air (JIS-B-8610 refrigeration capacity calculation method of the unit cooler for refrigeration). ).
[0006]
This measures the flow rate of air flowing through the cooler, and it is necessary to measure the flow rate of air at several measurement points in the cooler path and calculate the flow rate from the obtained flow rate. However, the airflow velocity in the cooler path is quite slow, so there are many difficulties in measurement in practice.
[0007]
The third method estimates the refrigeration capacity by the product of the refrigerant enthalpy difference at the inlet / outlet of the cooler and the mass flow rate of the refrigerant. In this method, the enthalpy is calculated from the measured temperature value and the measured pressure value of the refrigerant. The mass flow rate of the refrigerant is calculated by measuring the volume flow rate and multiplying it by the density of the refrigerant (JIS-B-8626 refrigeration unit cooler refrigeration capacity test method).
[0008]
Furthermore, the fourth method obtains the refrigerant flow rate calculated from the product of the temperature difference of the cooling water at the condenser inlet / outlet of the water-cooled condenser unit and the amount of cooling water, and multiplies the refrigerant flow rate by the refrigerant enthalpy difference at the cooler inlet / outlet. Thus, the refrigeration capacity is estimated. Instead of calculating the mass flow rate of the refrigerant, the temperature difference of the cooling water and the cooling water amount are measured, and the refrigerant flow rate is obtained from the product of the two parameters. Thereafter, the refrigerating capacity can be calculated in the same procedure as the third method (JIS-B-8626 refrigerating unit cooler refrigerating capacity test method).
[0009]
[Problems to be solved by the invention]
However, each of the above test methods has the following difficulties. In the first method, it is necessary to measure the time course of the temperature in the examination room one by one to confirm that the temperature does not change with time, that is, that the equilibrium condition is satisfied. For this reason, when the heat capacity of the examination room becomes large, a great deal of time must be spent until the state is settled. In addition, heat leakage from the laboratory wall tends to occur, and there is a problem that the calculated value cannot be trusted due to measurement errors. Furthermore, it is premised on the establishment of an equilibrium condition, and measurement is almost impossible in an unsteady state.
[0010]
In the second method, the air amount in the cooler path is measured too slowly and cannot be measured accurately. According to the current standard, an error of 0.2 meters per second (equivalent to about 10%) is allowed for wind speed measurement, and it is unavoidable that the same level of error occurs in calculating the cooling capacity. On the other hand, an error of several percent may occur in the measurement of air temperature.
[0011]
Furthermore, in the third method, it is necessary to measure the temperature and pressure of the refrigerant at the inlet / outlet of the cooler in order to estimate the enthalpy of the refrigerant. In addition, there is no means for directly measuring the mass flow rate of the refrigerant, and the density of the refrigerant is estimated from other experiments and is calculated by multiplying the measured value of the volume flow rate of the refrigerant by this density. Furthermore, it is necessary to determine the substantial mass flow rate in consideration of the mixing amount of oil based on the obtained mass flow rate. As described above, there is a possibility that measurement errors may be included in all of these parameters in the calculation of the refrigerating capacity, and there is a problem that errors are likely to occur in calculating the refrigerating capacity.
[0012]
Further, in the fourth method, the refrigerant flow rate can be obtained by the cooling water amount that can be easily measured instead of the mass flow rate of the refrigerant that is difficult to estimate. There is a possibility that a measurement error may enter, and there is a difficulty that an error is likely to occur in calculating the refrigerating capacity. Moreover, the number of measurement objects increases further, which is not preferable.
[0013]
In addition, in the first and second methods, only sensible heat is used for measuring the refrigerating capacity. Even if this method is used, if the temperature and humidity of the space to be cooled are almost constant, it is possible to obtain an almost correct estimated value for evaluating the refrigerating capacity. If not only the sensible heat removal capacity but also the latent heat removal capacity are not measured at the same time in the space where the outside air frequently enters, the cooling capacity of the cooler cannot be accurately evaluated.
[0014]
An object of the present invention is to suppress a measurement error as much as possible, and a refrigeration capacity test method capable of estimating a refrigeration capacity with extremely high accuracy even when depending on not only sensible heat but also latent heat, and its method To provide an apparatus.
[0015]
[Means for Solving the Problems]
The refrigeration capacity test method according to the present invention includes a first process of cooling air flowing in a partitioned area in a space to be cooled by a cooler, and a second process of heating the obtained low-temperature air with an electric heater. In the estimation of the cooling capacity of the cooler, in the second process, the decrease in the sensible heat of air in the first process and the increase in the sensible heat of air in the second process are balanced. While adjusting the input power of the heater, generated in accordance with the sensible heat of the electromotive force generated according to the sensible heat held in the air before cooling in the first process and the air after heating in the second process The refrigerating capacity of the cooler is estimated on the basis of the integrated power amount when the balance between the potentials of the two electric potentials is maintained.
[0016]
In such a test method, there is no need to measure various parameters using a meter to estimate the cooling capacity of the cooler, it is possible to reliably avoid measurement errors and to improve accuracy significantly. Is possible.
[0017]
Furthermore, it is not necessary to establish an equilibrium condition that is measured at different times. For this reason, it is not forced to measure for a long time to find the refrigerating capacity, and the refrigerating capacity of the cooler can be measured in a short time.
[0018]
Further, it is not affected by the heat capacity and heat leakage of the examination room, and it is possible to avoid measurement errors and improve accuracy.
[0019]
The “cooled space” in the method of the present invention refers to any space where there is air to be cooled, where the air is in contact with the refrigerant flowing in the evaporator tube through the heat transfer surface. it can. This cooled space includes, but is not limited to, a refrigerated warehouse, a refrigerated room, large / small-scale low-temperature space, a living space, a facility space, a transport / ship space, a vehicle space, and the like.
[0020]
In addition to the first and second processes, the refrigeration capacity test method of the present invention different from the above provides a process of humidifying with a humidifier, and the sensible heat held by the air before cooling and the air after heating are held. In addition to the thermoelectromotive force generated according to sensible heat, the difference between the thermoelectromotive force generated according to the latent heat of the air before cooling and the thermoelectromotive force generated according to the latent heat of the air after humidification is measured, The dehumidifying and refrigeration capacity of the cooler is estimated based on the integrated electric energy when the equilibrium state of both potentials is maintained.
[0021]
In such a test method, it is not necessary to measure various parameters using a meter to measure the refrigeration capacity, and it is possible to surely avoid the introduction of measurement errors, especially not only sensible heat. The refrigerating capacity can be estimated with extremely high accuracy when depending on the latent heat.
[0022]
In addition, the refrigerating capacity test method of this invention can be comprised so that the order may be replaced about a 1st process and a 2nd process. That is, it has a first process of heating by an electric heater and a second process of cooling by a cooler, and an increase in sensible heat of air in the first process and a decrease in sensible heat of air in the second process. In the first process, the electric power of the heater is adjusted in the first process, while the electromotive force generated according to the sensible heat held in the air before heating in the first process and after cooling in the second process. Measure the difference from the thermoelectromotive force generated according to the sensible heat of the air, and estimate the refrigerating capacity of the cooler based on the integrated power amount when the equilibrium state of both potentials is maintained Also good.
[0023]
In addition, the refrigeration capacity testing apparatus according to the present invention is provided near the inlet of the heat insulation area, the duct forming the heat insulation area, in which air flows in a certain direction, and near the outlet of the heat insulation area. An electric heater that heats the air, a plurality of first thermocouples that are upstream of the cooler and generate a thermoelectromotive force according to the sensible heat of the air flowing into the cooler, and downstream of the heater A plurality of second thermocouples that generate a thermoelectromotive force according to sensible heat of the air flowing out of the heater, a potential applied from the first thermocouple, and a potential applied from the second thermocouple A potentiometer that measures the difference and an integrating wattmeter that measures the amount of power supplied to the heater are provided.
[0024]
Furthermore, in the refrigeration capacity testing device of the present invention, desirably, the duct includes a bell mouth-shaped lead portion.
[0025]
DETAILED DESCRIPTION OF THE INVENTION
(First embodiment)
A first embodiment of the method of the present invention will be described with reference to the drawings. This embodiment is applied to a refrigerated warehouse. In FIG. 1, the refrigeration capacity testing apparatus of the present embodiment includes a cooler 2 that supplies cold air to the inside of a refrigerated warehouse 1 and an electric heater 3 that heats air. The cooler 2 and the heater 3 are arranged in series in a region defined by a duct 4 provided with a heat insulating material (not shown), that is, a heat insulating region 5. The adiabatic zone 5 is a region determined in accordance with the arrangement section of the first and second thermocouples, which are the zero level measurement equilibrium detecting means described later in the duct 4. Therefore, the air flowing through the heat insulating area 5 can flow in only from the inlet of the duct 4 and flow out only from the outlet of the duct 4. The duct 4 is provided with a bell mouth-shaped lead portion 6 for keeping the airflow velocity uniform. In addition, the duct 4 includes a fan 7 that circulates cold air into the refrigerated warehouse 1.
[0026]
Furthermore, the refrigeration capacity test apparatus includes first thermocouples 8a, 8b, 8c, 8d, and 8e that generate thermoelectromotive force in response to sensible heat held by the air flowing into the cooler 2 at the entrance of the heat insulating area 5. In addition, second thermocouples 9 a, 9 b, 9 c, 9 d, and 9 e that generate a thermoelectromotive force according to sensible heat held by the air flowing out from the heater 3 are provided at the outlet of the heat insulating area 5. The first thermocouples 8 a, 8 b, 8 c, 8 d, and 8 e are arranged with their temperature measuring contacts so as to come into contact with the air that flows in the whole area of the heat insulating area 5. On the other hand, the second thermocouples 9a, 9b, 9c, 9d, and 9e are provided with respective temperature measuring contacts so as to come into contact with the air flowing in the whole area of the heat insulation area 5 outlet. The first thermocouples 8a, 8b, 8c, 8d, and 8e and the second thermocouples 9a, 9b, 9c, 9d, and 9e are, as will be described in detail later, a potentiometer 10 that measures the difference in thermoelectromotive force. Connected with.
[0027]
In addition, a lattice-like louver 11 is provided between the cooler 2 and the heater 3 in the heat insulating area 5 to block heat transfer by radiation. Further, the heater 3 includes a control device 12 that controls the air temperature. Input power is supplied from a power source (not shown) to the heater 3 via the control device 12. In addition, the refrigeration capacity testing apparatus of the present embodiment includes an integrating wattmeter 13 that measures the input power to the heater 3. Furthermore, the cooler 2 includes a condensing unit 14 that controls the cold air temperature, and the fan 7 has a controller 15 that controls the number of rotations. In addition, a cooler (not shown) is provided inside the refrigerated warehouse 1, and the intruding heat from the outside and the heat generated by the fan 7 are offset to keep the temperature in the refrigerated warehouse 1 constant.
[0028]
FIG. 2 shows a wire connection method for the first thermocouples 8a, 8b, 8c, 8d, and 8e and the second thermocouples 9a, 9b, 9c, 9d, and 9e. The second thermocouple 9a connects the leg of the temperature measuring contact to the leg of the temperature measuring contact of the first thermocouple 8a. The first thermocouple 8a connects the + leg of the temperature measuring contact to the + leg of the temperature measuring contact of the second thermocouple 9b. The other second thermocouples 9b, 9c, 9d, and 9e similarly have their temperature measuring contact-legs connected to the temperature measuring contact-legs of the first thermocouples 8b, 8c, 8d, and 8e. The other first thermocouples 8b, 8c and 8d similarly connect the + leg of the temperature measuring contact to the + leg of the temperature measuring contact of the second thermocouples 9c, 9d and 9e. The last first thermocouple 8 e has a + leg connected to the potentiometer 10. Further, the second thermocouple 9 a has a + leg connected to the potentiometer 10.
[0029]
In measuring the refrigerating capacity, first, the fan 7 is activated to increase the speed. Further, the refrigeration apparatus is activated to operate the cooler 2. At the same time, a voltage is applied to the heater 3 from the power supply. When the fan 7 is started, air in the refrigerated warehouse 1 flows into the duct 4 from the bell mouth-shaped lead portion 6. This air is rectified by the lead portion 6 and flows toward the cooler 2 at a substantially uniform speed.
[0030]
The air flowing in the cooler 2 is deprived of heat by the refrigerant flowing in the evaporation pipe (not shown), and the temperature drops. Subsequently, the low-temperature air flows over the heater 3, where it is heated by convective heat transfer and the temperature rises.
[0031]
During this measurement, the cooling capacity of the cooler 2 is measured by the zero method. Prepare a reference amount that is variable in size from the zero method, independently of the amount to be measured, and compare this reference amount directly with the measured amount, balance it, and measure it from the value of the reference amount when balanced Refers to the method of knowing the quantity. In this embodiment, for this zero position measurement, the thermoelectromotive force generated by the sensible heat of the air at that time is measured at the entrance of the heat insulation zone 5 and at the exit of the heat insulation zone 5.
[0032]
The first thermocouples 8a, 8b, 8c, 8e, and 8e come into contact with the air before heat exchange with the refrigerant at the entrance of the heat insulating zone 5, and generate a thermoelectromotive force having a value corresponding to the sensible heat of the air. On the other hand, the second thermocouples 9a, 9b, 9c, 9d, and 9e come into contact with the air heated by the heater 3 at the outlet of the heat insulating area 5, and generate a thermoelectromotive force having a value corresponding to the sensible heat of the air. A difference in thermoelectromotive force generated in each thermocouple 8a, 8b, 8c, 8d, 8e and thermocouple 9a, 9b, 9c, 9d, 9e is given to the potentiometer 10, respectively.
[0033]
The difference in thermoelectromotive force generated in each of the thermocouples 8a, 8b, 8c, 8d, and 8e and the thermocouples 9a, 9b, 9c, 9d, and 9e is in an equilibrium state, that is, a value that is zero or slightly deviated from zero. Presents. A slight deviation from zero corresponds to the difference between the sensible heat of the air before heat exchange with the refrigerant and the sensible heat of the heated air. A slight increase / decrease is made, the difference is kept further small, and finally the display of the potentiometer 10 is held at zero. When the potentiometer 10 continues to indicate zero, it is assumed that a thermal equilibrium state has been realized, and the display of the integrating wattmeter 13 is mechanically read and stored in a storage device (not shown). Divide the read accumulated power amount by the accumulated time to calculate the refrigeration capacity per unit time in watts.
[0034]
In the measurement by the zero position method, it is only necessary to confirm that the display of the potentiometer 10 is zero. For example, there is no need to read the temperature itself using a meter, and it is ensured that a conversion error is introduced along with the temperature measurement. Can be avoided. Further, since there is no need to measure the air volume, it is possible to avoid an error from being introduced with the measurement.
[0035]
Incidentally, in the above test method, when measuring the refrigerating capacity, the integrating wattmeter 13 is involved only as a meter, and this can be obtained with high accuracy by using a precision grade.
[0036]
In the present embodiment, the temperature measuring contacts of a plurality of thermocouples are connected to measure the difference in thermoelectromotive force, and therefore various parameters are measured using a meter to estimate the cooling capacity of the cooler. It is not necessary, it is possible to avoid measurement errors, and the refrigeration capacity can be estimated with extremely high accuracy.
[0037]
Further, it is not necessary to establish an equilibrium condition for measuring at different times, which is required when measuring the freezing capacity using an examination room. Thereby, it is not forced to measure over a long time, and the refrigerating capacity of the cooler can be measured in a short time.
[0038]
Furthermore, it is not affected by the heat capacity and heat leakage of the examination room, it is possible to avoid measurement errors and to improve accuracy.
[0039]
(Second Embodiment)
A different embodiment of the method of the present invention will be described with reference to FIG. The refrigeration capacity testing apparatus according to the present embodiment includes a humidifier 16 that contains moisture in the air on the downstream side of the heater 3. The humidifier 16 is connected to a water supply container (not shown), and water from the water supply container can be sent into the air as a mist. The humidifier 16 includes a control device 17 that controls the air humidity. Electric power is supplied to the humidifier 16 from a power source (not shown) via the control device 17. Further, the test apparatus includes an integrating wattmeter 18 that measures the input power to the humidifier 16.
[0040]
In addition, the refrigeration capacity testing apparatus includes first dry bulb thermocouples 8a, 8b, 8c, 8d, 8e and a first wet bulb that generate a thermoelectromotive force in the heat insulating area 5 upstream of the cooler 2 according to the temperature of air. Thermocouples 19a, 19b, 19c, 19d, and 19e are provided. Furthermore, this test apparatus has a second dry bulb thermocouple 9a, 9b, 9c, 9d, 9e and a second one that generate a thermoelectromotive force in the heat insulating area 5 on the downstream side of the heater 3 according to the temperature of the air after humidification. Wet bulb thermocouples 20a, 20b, 20c, 20d, and 20e are provided.
[0041]
Although not shown in order to avoid complication of the drawings, the first wet bulb thermocouples 19a, 19b, 19c, 19d, 19e and the second wet bulb thermocouples 20a, 20b, 20c, 20d, The wire connection method to 20e is the same as the wire connection method of the first embodiment, and the last first wet bulb thermocouple 19e connects the + leg to the potentiometer 21, and The wet bulb thermocouple 20 a has a + leg connected to the potentiometer 21.
[0042]
In the present embodiment, as in the first embodiment, it is possible to measure the refrigeration capacity when it depends on sensible heat, but in addition to this, the dehumidification refrigeration capacity when it depends on latent heat Can be measured. Moisturized air flows around the first dry bulb thermocouples 8a, 8b, 8c, 8d, 8e and the first wet bulb thermocouples 19a, 19b, 19c, 19d, 19e at the entrance of the heat insulation zone 5. Each thermocouple generates a thermoelectromotive force according to the ambient temperature and humidity.
[0043]
On the other hand, air mixed with water blown out as mist from the humidifier 16 at the outlet of the heat insulating zone 5 is the second dry bulb thermocouples 9a, 9b, 9c, 9d, 9e and the second wet bulb thermocouples 20a, 20b, 20c. , 20d, and 20e, and the thermocouple generates a thermoelectromotive force according to the ambient temperature and humidity.
[0044]
The difference in thermoelectromotive force generated in each of the first dry bulb thermocouples 8a, 8b, 8c, 8d, 8e and the second dry bulb thermocouples 9a, 9b, 9c, 9d, 9e is in an equilibrium state, that is, zero. Or a value slightly deviating from zero. A slight deviation from zero corresponds to the difference between the sensible heat of the air before being cooled and the sensible heat of the air after being heated, so that the thermoelectromotive force is slightly increased or decreased by adjusting the heat output of the heater 3, The difference is further kept small, and finally the display of the potentiometer 10 is held at zero.
[0045]
Further, the difference in thermoelectromotive force generated in each of the first wet bulb thermocouples 19a, 19b, 19c, 19d, 19e and the second wet bulb thermocouples 20a, 20b, 20c, 20d, 20e is in an equilibrium state, that is, , Zero or a value slightly deviating from zero. A slight deviation from zero corresponds to the difference between the latent heat of the air before being cooled and the latent heat of the air after being humidified. Therefore, by adjusting the humidification amount of the humidifier 16, the thermoelectromotive force is slightly increased or decreased. The difference is further kept small, and finally the display of the potentiometer 21 is held at zero. When the potentiometer 10 and the potentiometer 21 continue to indicate zero, it is assumed that an equilibrium state of heat and moisture has been realized, the display of the integrated wattmeter 13 and the integrated wattmeter 18 is read, and the read integrated power Divide the amount by the accumulated time to calculate the dehumidifying refrigeration capacity per unit time in watts.
[0046]
As described above, in the present embodiment, it is possible to reliably avoid measurement errors when measuring the refrigerating capacity, and in particular, with extremely high accuracy when depending not only on sensible heat but also on latent heat. Dehumidifying and freezing capacity can be estimated.
[0047]
Furthermore, it becomes possible to measure the latent heat removal capability simultaneously with the sensible heat removal capability, and it is possible to estimate the refrigeration capability for a cooler for a wider range of applications.
[0048]
【The invention's effect】
According to the present invention, it is not necessary to measure various parameters using an instrument to estimate the cooling capacity of the cooler, and it is possible to reliably avoid measurement errors, not only sensible heat but also latent heat. Therefore, it is possible to estimate the refrigerating capacity with extremely high accuracy.
[0049]
Further, it is not necessary to establish an equilibrium condition that is measured at different times, so that it is not forced to perform measurement over a long time, and the refrigeration capacity of the cooler can be measured in a short time.
[0050]
Further, it is not affected by the heat capacity and heat leakage of the examination room, and it is possible to avoid measurement errors and improve accuracy.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a first embodiment of a refrigeration capacity testing apparatus according to the present invention.
FIG. 2 is a schematic diagram showing an example of connection of thermocouple wires according to the present invention.
FIG. 3 is a configuration diagram showing a second embodiment of a refrigeration capacity testing device according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Cold storage 2 Cooler 3 Heater 4 Duct 8a, 8b, 8c, 8d, 8e 1st (dry bulb) thermocouple 9a, 9b, 9c, 9d, 9e 2nd (dry bulb) thermocouple 10, 21 Potentiometer 13, 18 Integrated wattmeters 19a, 19b, 19c, 19d, 19e First wet bulb thermocouple 20a, 20b, 20c, 20d, 20e Second wet bulb thermocouple

Claims (5)

A first process of cooling air flowing in a partitioned area in the space to be cooled by a cooler, and a second process of heating the obtained low-temperature air by an electric heater, In estimating the refrigerating capacity, the input power of the heater in the second process so that the decrease in sensible heat of air in the first process and the increase in sensible heat of air in the second process are balanced. The thermoelectromotive force generated according to the sensible heat held in the air before cooling in the first process and the heat generated according to the sensible heat held in the air after heating in the second process A refrigerating capacity test method in which a difference from an electromotive force is measured, and the refrigerating capacity of the cooler is estimated based on an integrated power amount when an equilibrium state of both potentials is maintained. In addition to the first and second processes, a process of humidifying with a humidifier is provided, in addition to the sensible heat held by the air before cooling and the thermoelectromotive force generated according to the sensible heat held by the air after heating. The difference between the thermoelectromotive force generated according to the latent heat of the air before cooling and the thermoelectromotive force generated according to the latent heat of the air after humidification is measured, and the equilibrium state of both potentials is maintained. 2. The refrigeration capacity test method according to claim 1, wherein the dehumidifying and refrigeration capacity of the cooler is estimated based on an integrated electric energy. A first step of heating the air flowing in a partitioned area in the space to be cooled by an electric heater, and a second step of cooling the obtained high-temperature air by a cooler, In estimating the refrigerating capacity, the input power of the heater in the first process so that the increase in sensible heat of air in the first process and the decrease in sensible heat of air in the second process are balanced. The thermoelectromotive force generated according to the sensible heat held in the air before heating in the first process and the heat generated according to the sensible heat held in the air after cooling in the second process A refrigerating capacity test method in which a difference from an electromotive force is measured, and the refrigerating capacity of the cooler is estimated based on an integrated power amount when an equilibrium state of both potentials is maintained. A duct that forms a heat insulation zone in which air flows in a certain direction, a cooler that is provided near the inlet of the heat insulation zone, cools the air, and an electric heater that heats the air near the outlet of the heat insulation zone A plurality of first thermocouples that are on the upstream side of the cooler and generate a thermoelectromotive force corresponding to the sensible heat of the air flowing into the cooler; Measuring a difference between a plurality of second thermocouples that generate a thermoelectromotive force according to sensible heat of the air and a potential applied from the first thermocouple and a potential applied from the second thermocouple A refrigerating capacity test apparatus comprising: a potentiometer for measuring power and an integrating wattmeter for measuring the amount of power supplied to the heater. The refrigerating capacity test apparatus according to claim 4, wherein the duct includes a bell mouth-shaped lead portion.

Images