JP4573196B2 - Air conditioner for precision temperature control - Google Patents

Description

  The present invention relates to an air conditioner for precise temperature control that is installed in a clean room or the like of a semiconductor manufacturing factory and normally operates continuously for 24 hours 365 days. More specifically, the present invention relates to a precision temperature control air conditioner in which the components of a compression refrigerator are unitized so that if a failure occurs in the refrigerator, the refrigerator can be quickly replaced with another one. Related to the machine.

Conventionally, a constant temperature air conditioner that accurately maintains a room temperature at a preset constant temperature is known, for example, from Patent Document 1 and the like. The constant temperature air conditioner of Patent Document 1 controls the heating amount of the electric heater based on the signal from the indoor temperature detector, and performs the capacity control of the compressor based on the signal from the supply air temperature detector, The room temperature is kept constant.
When such a constant temperature air conditioner is installed along with a semiconductor manufacturing apparatus or the like in a clean room, continuous operation for 24 hours and 365 days is fundamental. If a failure occurs in the refrigerant system of the compressor, the condenser, the expansion valve and the evaporator during continuous operation over a long period of time, the failure part is usually repaired on site. In doing so, the refrigerant must first be recovered, then the failed parts must be re-welded, the refrigerant system must be evacuated, and the refrigerant refilled. During repair work, it is necessary to pay attention to the fire during welding, and since there is a possibility of adverse effects on the surrounding environment where the constant temperature air conditioner is installed, such as refrigerant leakage, repair may not be possible in practice.

In such a case, it is necessary to remove the constant temperature air conditioner locally, repair it at a repair shop, and install it again on site. To re-install the air conditioner, it takes a long time to carry in the replacement device, remove the connected duct, power cable and cooling water pipe, and reconnect. In some cases, not only the production line is shut down, but the manufacturing of semiconductor products and the like is hindered, and the repair cost increases.
Therefore, it is desirable to reduce the repair time in the event of a failure as much as possible. The causes of failure of the constant temperature air conditioner include touch panel / board failure, sensor failure, etc., but these parts can be easily replaced in a short time. However, if a component incorporated in the refrigerant circuit such as a compressor or an expansion valve breaks down, it is not easy to replace it for the reasons described above, so that only the refrigerant circuit portion can be replaced (referred to as a refrigerant circuit unit). It is desirable to keep it. Examples of such conventional techniques include the following Patent Documents 2 and 3.

In Patent Document 2, an air inlet having a plurality of openings of the same shape and size is provided on one side surface of a case forming an air flow path, and an air cooler unitized to the same specifications is provided in these openings. An attached constant temperature air supply device has been proposed. In this air supply device, an air heater is disposed in a case, and an air cooler is constituted by an electronic refrigeration device using a Peltier element, a heat-conducting cooling channel, and a cooling water circulation radiator. The air cooler is supported by a support frame that is slightly inclined to the opening side and is provided near the opening of the case, and the downstream end of the air cooler projects outward from the case so as to surround the opening. It is fixed to the rectangular mounting frame via a packing. And when an air cooler fails, repair is performed by replacing the failed unit with another one.
Patent Document 3 discloses an air conditioner in which a plurality of compression-type refrigerant circuit units that are individually operable and can be taken out and stored in a casing are provided in parallel, and an evaporator air passage and a condenser air passage are provided in two upper and lower stages. Has been proposed. This air conditioner is intended to obtain a large capacity with a large air flow by providing a plurality of refrigerant circuits in order to facilitate assembling and carrying in narrow passages, etc. Are formed in the casing, and the refrigerant circuit units are sequentially pushed in from the side to be accommodated. Moreover, it is said that the ventilation fan of an evaporator and a condenser may be unitized.
Japanese Patent No. 2599632 JP-A-10-325567 JP 2003-130388 A

In the constant temperature air supply device of Patent Document 2 described above, a thermoelectric conversion element, an air temperature detector, and a controller are integrated into a detachable air cooler. Therefore, when an air cooler is replaced due to a failure of a thermoelectric conversion element that is a cold heat source, it is necessary to replace an air temperature detector / controller that has not failed, and the repair cost is excessive. On the other hand, if the air temperature detector / controller breaks down, it is necessary to remove the air cooler one by one to replace these parts, which takes time and trouble.
Moreover, the air conditioner of patent document 3 has a compression-type refrigerant circuit unit which can be taken out and stored. However, since precise temperature control is not aimed, no special consideration has been given to averaging the spatial temperature distribution on the downstream side of the compression refrigerant circuit unit. If you want to average the spatial temperature distribution on the downstream side of the compression refrigerant circuit unit, seal the air that bypasses the evaporator by sealing at least the gap between the casing of the unit and the air conditioner housing, the gap between the units, etc. Although it is necessary to block, such a description is not found in Patent Document 3.

  Therefore, an object of the present invention is to eliminate the above-mentioned problems of the prior art, to prevent air from bypassing the evaporator from entering the air flow path from the downstream side of the refrigerant circuit unit to the electric heater, and It is an object of the present invention to provide a precision temperature control air conditioner that is easy to maintain and maintain so that it can be easily replaced if a failure occurs in the refrigerant circuit unit.

In order to achieve the above object, the present invention provides a refrigerant circuit unit in which a compressor, a condenser, an expansion valve, an evaporator and a heat exchanger for the condenser are incorporated, and suction air exchanged by the evaporator from an outlet. An air circulation fan for supplying air to the outside, a baffle plate arranged sequentially on the upstream side of the fan, and an air passage chamber containing an electric heater, and a first air passage disposed between the baffle plate and the electric heater. One temperature sensor, and a second temperature sensor disposed between the air circulation fan and the air outlet, and the capacity of the compressor is controlled based on the air temperature detected by the first temperature sensor, and the second temperature In a precision temperature control air conditioner that controls the amount of heat generated by an electric heater based on the air temperature detected by a sensor, one side of the refrigerant circuit unit is covered with a detachable check plate, and the downstream opening of the refrigerant circuit unit And air flow channel The upstream opening of the bar communicates via a connecting duct, and an elastic packing is interposed between the lower end opening peripheral part on the downstream side of the refrigerant circuit unit and the lower end opening peripheral part on the upstream side of the connecting duct. The periphery of the upper end opening of the refrigerant circuit unit is provided with a taper that increases in the direction of one side surface covered with the inspection plate, and the periphery of the lower end opening of the connecting duct is also aligned with the periphery of the upper end opening of the refrigerant circuit unit. A taper is provided.
In the present invention, it is simple to fix a plurality of screw fasteners to the refrigerant circuit unit body and screw the inspection plate to the refrigerant circuit unit body. Further, when the condenser heat exchanger is constituted by water piping, the inspection plate portion where the inlet portion and the outlet portion are located is cut out, and the cutout portion can be detachably covered with another inspection plate. preferable.

In the precision temperature control air conditioner according to the present invention, one side of the refrigerant circuit unit is detachably attached with a check plate. For example, by removing a set screw for fixing the check plate, a failure has occurred in the refrigerant circuit unit. In this case, it is possible to easily take in and out the unit at the installation location. Therefore, it is possible to quickly replace the failed refrigerant circuit unit with another new unit. Moreover, since the inside of the refrigerant circuit unit can be easily inspected by opening the inspection plate, the maintenance and maintenance of the unit is simple.
In the precision temperature control air conditioner of the present invention, the downstream side of the refrigerant circuit unit and the upstream side of the air flow channel chamber communicate with each other via a connecting duct, and the periphery of the upper end opening of the refrigerant circuit unit and the lower end of the connecting duct An elastic packing is interposed between the peripheral portions of the opening to provide a taper that increases toward the inspection plate in the peripheral portion of the upper end opening of the unit, and a taper that matches the taper also in the peripheral portion of the lower end opening of the connecting duct. Is provided. Therefore, airtightness between the refrigerant circuit unit and the air flow path chamber is ensured. In addition, after replacing the failed refrigerant circuit unit, the new unit is simply pushed into the air conditioner body, ensuring airtightness between the unit and the connecting duct, and air that bypasses the evaporator or air outside the air conditioner. There is no risk of mixing in the downstream side of the unit.

Hereinafter, the present invention will be described in detail.
First, the outline of the precision temperature control air conditioner of the present invention will be described with reference to FIG. The precision temperature control air conditioner A main body is formed of an airtight housing and is divided into a suction chamber B, a refrigerant circuit unit C, an air flow path chamber D, and an electrical component storage chamber E in which mainly electrical components are disposed. The chamber E forms, for example, another exhaust system from the chamber B, the unit C, and the chamber D.
The refrigerant circuit unit C includes a compressor circuit, a condenser 2, an expansion valve 3 and an evaporator 4, and a refrigerant circuit composed of a refrigerant pipe connecting them, and heat exchange for the condenser that cools the condenser 2 with cooling water. 5 is incorporated. The heat exchanger 5 may be an air-cooled type that is cooled with air instead of the cooling water. Further, the evaporator 4 portion of the unit C and the air flow path chamber D are formed of a heat-insulating and airtight wall body.
The air passage chamber D is cooled by the baffle plate 6 for stirring the suction air cooled by the refrigerant circuit unit C, the first temperature sensor 7 for measuring the temperature of the air stirred by the baffle plate 6, and the unit C. An electric heater 8 for finally adjusting the temperature of the sucked air, an air circulation fan 9 for supplying air adjusted by the electric heater 8 to the outside of the air conditioner, and a second temperature sensor 10 for measuring the supply air temperature are arranged. Is done. In the electrical component storage chamber E, the motor unit 11 of the fan 9, the first temperature sensor 7, the compressor control unit 12 connected to the compressor 1, the second temperature sensor 10 and the electric heater control connected to the electric heater 8. Part 13 is installed. An exhaust fan 14 is provided at one end opening of the chamber E, and various electric parts such as the motor unit 11 and the control board are cooled by the air sucked into the chamber E.

  The operation of the precision temperature control air conditioner A according to the present invention will be briefly described. Air sucked from the suction port 15 of the suction chamber B is cooled through the evaporator 4 in the refrigerant circuit unit C, and is heated by the electric heater 8. After being heated, air is supplied into the room from the air outlet 16 of the air flow channel chamber D. Meanwhile, based on the air temperature detected by the first temperature sensor 7, which is a compressor frequency control sensor disposed downstream of the evaporator 4, the compressor 1 is controlled by a signal from the compressor controller 12. Control the capacity. That is, when the air temperature is lower than a set value (for example, a temperature lower by 1 to 2 ° C. than the room temperature target temperature), the cooling capacity of the compressor 1 is reduced, and when the air temperature is higher than the set value, the cooling capacity is increased. The air temperature at the outlet is maintained within a predetermined setting range. The indoor air maintained in the predetermined temperature range in this manner is reheated by the electric heater 8, but based on the air temperature detected by the second temperature sensor 10, a signal from the electric heater control unit 13 is used. The amount of heat generated by the electric heater 8 is controlled, adjusted to a room temperature target temperature of ± 0.1 ° C., and supplied to the room.

Next, the precise temperature control air conditioner of the present invention will be specifically described.
2 to 5, in the precision temperature control air conditioner A, as described above, the inside of the rectangular parallelepiped airtight casing 17 becomes the suction chamber B, the refrigerant circuit unit C, the air flow path chamber D, and the electrical component storage chamber E. It is partitioned. More specifically, the unit C is arranged at the lower part of the air conditioner A, and the chamber E is arranged at the upper part on the front side. In the rear of the chamber E, the chamber D is arranged on one side (right side in FIG. 2), and the chamber B is arranged on the other side (left side in FIG. 2). There is no partition between the chamber B and the upstream side of the unit C, and they communicate with each other as they are. Further, the unit C and the chamber D communicate with each other in an airtight state.
In the refrigerant circuit unit C described in detail later, the refrigerant circuit including the evaporator 4 in which a meandering refrigerant pipe is fixed to a thin box-shaped thermally conductive metal plate 18 in which a large number of ventilation holes are formed, And the water piping 19 which comprises the heat exchanger 5 for condensers is incorporated. One side surface of the refrigerant circuit unit C is covered with an inspection plate 20, and the inspection plate 20 is screwed into a screw fixing bracket 21 having an L-shaped cross section fixed to four positions on the front side portion and the back side portion of the unit C main body. 21a is perforated and is detachably attached to the unit C main body using a retaining screw 22 (see FIG. 9 for details). On the front side inside the refrigerant circuit unit C, a substantially trapezoidal opening 23 communicating with the opening of the suction chamber B is formed.

  A baffle plate 6 is attached to the lower portion of the air flow chamber D through an interval with the electrical component storage chamber E in order to promote mixing of the air heat-exchanged by the evaporator 4. A fan casing 24 that houses the air circulation fan 9 is provided on the chamber E side above the chamber D, and is supported by a partition member 25 that partitions the chamber D and the chamber E. A first temperature sensor 7 is disposed between the lower end of the suction surface of the casing 24 and the tip of the baffle plate 6. The first temperature sensor 7 is fixed to the upper surface of the sheet metal gate-type base 26. Between the fan 9 and the air outlet 16 of the chamber D, the second temperature sensor 10 is preferably disposed on the air outlet surface of the casing 24. In addition, an electric heater 8 is provided in which a heating resistor such as a plurality of sheathed heaters arranged in parallel is tilted upward from the lower end portion of the suction surface and attached to the support member 27 (see FIG. 4). ). The support member 27 is provided with a space between a plurality of support plates that support the heating resistor so that the airflow resistance is minimized.

Referring to FIG. 3, the front upper portion of electrical component storage chamber E is covered with a detachable upper panel 28 in order to facilitate inspection of electrical components such as control boards of motor unit 11 and control units 12 and 13. It has been broken. The upper panel 28 is coupled to the main body of the air conditioner A with a retaining screw, and a handle 29 is provided on one side thereof. Furthermore, the upper panel 28 displays the target room temperature, the room temperature during operation, the on / off state of switches, the date / time, etc., a liquid crystal touch panel 30 for operating the switches, an indicator lamp 31 that is lit during operation, An earth leakage breaker 32 that cuts off the power supply when an electric leakage occurs in the electronic / electrical component and an emergency cut-off switch 33 that shuts off the power supply when an emergency occurs are provided.
Front lower portion of the chamber E is also covered with the side panels 34 of the detachable to facilitate inspection of the motor or the like below the cooling fan. The side panel 34 is coupled to the main body of the air conditioner A with a retaining screw, and a handle 35 is provided on one side thereof.

The upper end opening of the refrigerant circuit unit C and the lower end opening of the air flow path chamber D are communicated by a connecting duct 36, and an elastic member is formed between the upper end opening peripheral portion of the unit C and the lower end opening peripheral portion of the connecting duct 36. The packing 37 to be used is interposed. And the taper 38 which becomes high toward the one side surface covered with the inspection plate 20 is provided in the upper end opening peripheral portion of the unit C, and the upper end opening peripheral portion of the unit C is also provided in the lower end opening peripheral portion of the connecting duct 36. A taper is provided to match the above. Here, the flange 36a of the connecting duct 36 is attached to the periphery of the lower end opening of the chamber D. Further, the packing 37 is fixed to either one or both of the unit C and the connecting duct 36.
On the upper surface of the main body of the precision temperature control air conditioner A, a flange 39a of a cylindrical connecting portion 39 connected to the indoor air suction duct so as to cover the suction port 15 of the suction chamber B and the blowout port 16 of the air flow passage chamber D. And the flange 40a of the cylindrical connection part 40 connected to an air supply duct is each fixed (refer FIG. 5). Such an air flow path system is exclusively for maintaining the semiconductor manufacturing apparatus and the like at a constant temperature, and the air conditioner A is integrated with the electrical component storage chamber E that constitutes a separate air flow path system. Is provided. In this air flow path system, the indoor air sucked through the filter 41 cools the electrical parts such as the motor part 11 of the fan 9 and the control plates of the control parts 12 and 13 protruding into the chamber E, The air is exhausted indoors by the cooling fan 42. Further, casters 44 are attached to the lower four corners of the air conditioner A main body.

Next, the refrigerant circuit unit C will be specifically described with reference to FIGS. 6 and 7.
The refrigerant circuit includes a two-cylinder rotary compressor 1, a condenser 2, an electronic expansion valve 3, an evaporator 4 fixed to the metal plate 18 and an accumulator 45, and refrigerant pipes 46a to 46e that sequentially connect them. Is done. One of the refrigerant pipes 46 e is located in the upper gas phase part in the accumulator 45 and the other end is connected to each cylinder part in the compressor 1.
In the compressor 1, a receiving plate 47 provided integrally at the bottom is fixed to a support base 48 with a long screw 49. The refrigerant pipe constituting the condenser 2 has a substantially U shape or a substantially U shape rotated by 90 °, and the water pipe 19 penetrates the inside thereof. That is, the condenser heat exchanger 5 includes a double pipe having the refrigerant pipe as an outer pipe and the water pipe 19 as an inner pipe. The inlet 50 and the outlet 51 of the water pipe 19 are formed with screw parts so that they can be connected to the circulating pipe of the circulating cooling water and the return pipe via the connecting members 50a and 51a. The upper pipe of the condenser 2 (heat exchanger 5) is supported by a fixing bracket 52 fixed to the unit C main body, and the refrigerant condensed with the cooling water sent into the water pipe 19 easily flows downstream. is doing. Therefore, it is preferable to incline the upper pipe of the condenser 2 so as to descend toward the downstream side.

  A stepping motor 53 is incorporated in the electronic expansion valve 3, and the opening degree of the expansion valve 3 is adjusted so that the refrigerant pipe surface temperature difference at the inlet / outlet of the evaporator 4 is constant. Below the evaporator 4, a drain pan 54 is disposed that receives drain water that is condensed when the indoor air undergoes heat exchange. The bottom of the drain pan 54 is inclined, and a drain pipe 55 is connected to the deepest part thereof. A screw portion is formed at the discharge port portion 56 of the drain pipe 55 so as to be connectable to the drain water discharge pipe via the connection member 56a. In addition, the inlet 50 and outlet 51 of the water pipe 19 and the outlet 56 of the drain pipe 55 may be connected to the cooling water forward and return pipes and the drain water discharge pipe in a one-touch manner. it can.

In the precision temperature control air conditioner A of the present invention, in order to perform precise temperature control at the target temperature ± 0.1 ° C. level, it is necessary to control the air in front of the electric heater 8 within the range of ± 0.3 ° C. of the set temperature. Therefore, highly accurate capacity control of the refrigerator is performed. In order to control the capacity of the refrigerator with high accuracy, the measured temperature of the first temperature sensor (compressor frequency control sensor) 7 needs to be equal to the average temperature of the air cooled by the evaporator 4. However, since the refrigerant temperature in the evaporator 4 and the amount of passing air vary, the air downstream of the evaporator 4 usually has a temperature distribution of several degrees Celsius. Therefore, the baffle plate 6 is provided to mix the outlet air of the evaporator 4 to reduce the variation in temperature distribution.
The air temperature is not sufficiently equalized only by providing the baffle plate 6, and as the number of baffle plates 6 increases, the air pressure loss increases and the power of the fan 9 also increases. Therefore, the first temperature sensor 7 Is used. As shown in FIG. 8 (A), the first temperature sensor 7 is a ribbon in which platinum resistance temperature detectors 7b are dispersed at appropriate intervals at a plurality of points in the film 7a, in this embodiment, at five points. Sensor (Pt100Ω: 20Ω × 5). Reference numeral 57 denotes a conducting wire connected to the compressor control unit 12. According to the first temperature sensor 7, a resistance value obtained by averaging the temperatures at the respective points is output from the first temperature sensor 7. Therefore, even if there is a temperature distribution at each measurement point, a measurement value close to the average value is output.

In addition, in order to perform precise temperature control at a level of ± 0.1 ° C., the measured temperature of the second temperature sensor (electric heater control sensor) 10 needs to be equal to the average temperature of the blown air within a range of ± 0.1 ° C. is there. For this purpose, the air temperature after mixing by the air circulation fan 9 is measured by the second temperature sensor 10. In general, since the air temperature of the fan 9 outlet surface has a temperature distribution of about ± 0.1 ° C., the present invention measures the air temperature of the fan 9 outlet surface or the vicinity thereof, and is close to the average value regardless of the air volume. The second temperature sensor 10 is disposed at a point where a measured value can be obtained.
As shown in FIGS. 8B and 8C, the second temperature sensor 10 is composed of a rod-shaped L-shaped platinum resistance temperature detector (Pt100Ω) 10a. The resistance temperature detector 10a is fixed to the fixing bracket 58 whose vertical base is attached to the fan casing 24 via the electric insulating member 10b so that the longitudinal direction thereof is orthogonal to the air flow.

FIG. 9 shows a state in which the failed refrigerant circuit unit is pulled out from the precision temperature control air conditioner main body, and the connecting duct and the packing are separated.
Referring to FIG. 9, a pair of rail-like mounts 60 is installed on the bottom surface of air conditioner body portion 59, and refrigerant circuit unit C is placed thereon. A notch or a groove can be formed at a position corresponding to the gantry 60 on the bottom surface of the unit C main body. An upper surface opening 61 communicating with the connection duct 36 and the opening of the air flow path chamber D is formed at the rear upper surface of the unit C.
A portion of the inspection plate 20 where the inlet portion 50 and the outlet portion 51 of the water pipe 19 and the discharge port portion 56 of the drain pipe 55 are located is cut out, and the cutout portion 20b is detachably covered with another inspection plate 62. The The inspection plate 62 is provided with through holes 63a to 63c through which connection portions 51a, 50a, 56a connected to the outlet portion 51, the inlet portion 50, and the discharge port portion 56 pass. In order to ensure airtightness, packing may be interposed between the connecting members 51a, 50a, 56a and the through holes 63a to 63c as necessary. Further, in the vicinity of the inspection plate 20, a plurality of screw holes 20a are drilled in addition to the portions corresponding to the screw holes 21a of the screw stopper 21. Similarly, the inspection plate 62 is also drilled with screw holes 62a. . The inspection plates 20 and 62 are screwed to the screw fixing bracket 21 and the refrigerant circuit unit C main body through the set screws 22 through the screw holes 20a and 62a.

  In order to take out the failed refrigerant circuit unit C from the air conditioner main body 59, the water pipe 19 and the drain pipe 55 are first drained, and the forward pipe and return pipe connected to the inlet 50 and outlet 51 of the water pipe 19 are returned. The pipe connection members 50a and 51a and the drain water discharge pipe connection member 56a connected to the discharge port 56 of the drain pipe 55 are removed. Next, the stop screw 22 that stops the inspection plate 62 is removed and the inspection plate 62 is removed, and the stop screw 22 that also stops the inspection plate 20 is removed and the inspection plate 20 is removed. Either of the inspection plate 62 and the inspection plate 20 may be removed first. Next, the refrigerant circuit unit C is pulled out to the front. At this time, since the plurality of wires 64 are connected by the connector 65 or the like, if the connector 65 and the temperature sensor in the refrigerant circuit are removed, the failed refrigerant circuit unit C can be completely separated from the air conditioner main body 59. it can.

  The replacement operation of the new unit C after pulling out the failed refrigerant circuit unit C may be performed in the reverse order as described above. That is, the connector 65 is connected and a temperature sensor in the refrigerant circuit is attached. Prior to this operation, the leading end side of a new refrigerant circuit unit C may be placed on the gantry 60. Next, the unit C placed on the gantry 60 is completely pushed into the air conditioner main body 59. At this time, since the taper 38 is formed on the upper surface of the unit C and the lower surface of the connecting duct 36, when the unit C is pushed in, the packing 37 interposed between the tapered surfaces is automatically interposed between the unit C and the connecting duct 36. Close contact with. Therefore, the airtightness between the unit C and the connecting duct 36 is ensured. Next, the inspection plate 62 is screwed to the frame of the unit C, and the inspection plate 20 is screwed to the screw fixing bracket 21 and the frame of the unit C. Thereafter, the connection members 50a and 51a for the cooling water forward and return pipes and the connection member 56a for the drain water discharge pipe are respectively connected to the inlet 50 and outlet 51 of the water pipe 19 and the outlet 56 of the drain pipe 55. Connecting. Finally, when the cooling water is filled in the water pipe 19, the replacement operation of the refrigerant circuit unit C is completed.

In the above precision temperature control air conditioner A, the example in which the inspection plate 20 and the inspection plate 62 covering the cutout portion 20b are separated has been described. However, when the air conditioner A is relatively small, One side of the refrigerant circuit unit C can be covered with a single inspection plate in which the inspection plate 20 and the inspection plate 62 are integrated.
The number of screws 21 is not particularly limited as long as the airtightness of the refrigerant circuit unit C is ensured. Further, the screw stopper 21 is not necessarily a necessary member, and the inspection plate 20 can be directly and detachably attached to the main body of the refrigerant circuit unit C using the stopper screw 22.
In order to facilitate the insertion and removal of the refrigerant circuit unit C, it is preferable that the handle is attached to, for example, the left and right of the inspection plate 20. In that case, the above-described replacement work procedure for the failed refrigerant circuit unit C can be changed. For example, the above-described operation may be performed after the refrigerant circuit unit C is first pulled forward. Further, either the drainage / piping connection member and the inspection plate 20 or 62 may be removed first or the connector 65 may be removed. The replacement operation of the new refrigerant circuit unit C may be performed in the reverse order to the above-described operation procedure, and details thereof are within the obvious range of those skilled in the art from the above description, and the description thereof will be omitted.

The precision temperature control air conditioner of the present invention has the following operations and effects.
If there is a gap in the space at the outlet side of the evaporator in the refrigerant circuit unit, air that is not temperature-controlled enters the upstream air of the electric heater, bypassing the evaporator. Since it is necessary to control the upstream air of the electric heater to about ± 0.3 ° C. for precise temperature control, the influence of this mixed air cannot be ignored. However, in the present invention, a taper is provided in the peripheral part of the downstream opening of the refrigerant circuit unit, and the packing is interposed between the peripheral part of the upstream opening of the connecting duct. Therefore, when the refrigerant circuit unit is set at a predetermined position of the air conditioner body, the packing is automatically compressed, so that the separation of the refrigerant circuit unit and its airtightness are ensured. At the same time, the refrigerant circuit unit is easily pulled out.
Since the refrigerant circuit and, if necessary, the heat exchanger for the condenser are unitized as one refrigerant circuit unit, when the refrigerant circuit unit breaks down, it is possible to perform replacement work by one operator and repair In addition to shortening the time, (1) There is no risk of fire due to the elimination of welding work on site, and clean room environmental pollution is prevented. (2) If there is a concern about refrigerant leakage, measure the weight of the refrigerant circuit unit. (3) When manufacturing a precision temperature control air conditioner and filling with refrigerant, the refrigerant circuit unit is filled with the refrigerant filling machine first, and then the refrigerant circuit unit can be attached to the air conditioner body. This saves the trouble of transporting the air conditioner body to the refrigerant filling machine.

It is a conceptual diagram of the air conditioner for precision temperature control of this invention. It is a partially broken front view of the precision temperature control air conditioner which shows one Example of this invention, and shows that a refrigerant circuit unit can be freely taken in and out in an air conditioner main body. FIG. 3 is a drawing excluding a broken portion of FIG. 2. It is a partially broken side view of FIG. FIG. 4 is a top view of FIG. 3. It is an enlarged view of the refrigerant circuit unit with a connection duct in the precision temperature control air conditioner shown in FIG. It is a partially broken side view of FIG. (A) is a top view of the first temperature sensor, (B) is a top view of the second temperature sensor disposed in the precision temperature control air conditioner, and (C) is a CC line of (B). FIG. It is a principal part perspective view of the air conditioner for precision temperature control of this invention which shows an example of the state by which the refrigerant circuit unit was pulled out.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Condenser, 3 ... Expansion valve, 4 ... Evaporator, 5 ... Heat exchanger for condensers, 6 ... Baffle plate, 7 ... No. One temperature sensor (ribbon sensor), 7b ... Resistance temperature detector, 8 ... Electric heater, 9 ... Air circulation fan, 10 ... Second temperature sensor, 16 ... Air outlet, DESCRIPTION OF SYMBOLS 19 ... Water piping, 20 ... Inspection board, 20b ... Notch part, 21 ... Screw fixing bracket, 22 ... Stop screw, 36 ... Connection duct, 37 ... Packing, 38 ... Taper, 50 ... Water pipe inlet, 51 ... Water pipe outlet, 52 ... Condenser mounting bracket, 56 ... Drain pipe outlet, 61 ... Refrigerant circuit unit Upper surface opening, 62 ... Another inspection plate, A ... Precise temperature control air conditioner, C ... Refrigerant circuit unit, D ... Air flow path chamber.

Claims (5)

  A refrigerant circuit unit incorporating a compressor, a condenser, an expansion valve, an evaporator and a heat exchanger for the condenser, and an air circulation fan for supplying the intake air heat-exchanged by the evaporator to the outside from the outlet, Air flow chambers containing baffle plates and electric heaters sequentially arranged on the upstream side, a first temperature sensor arranged in an air flow path between the baffle plates and the electric heaters, an air circulation fan and a blower And a second temperature sensor disposed between the outlets, wherein the capacity of the compressor is controlled based on the air temperature detected by the first temperature sensor, and the electric power is detected based on the air temperature detected by the second temperature sensor. In a precision temperature control air conditioner that controls the amount of heat generated by the heater, one side surface of the refrigerant circuit unit is covered with a detachable inspection plate, and the downstream opening of the refrigerant circuit unit and the upstream opening of the air channel chamber Connected duct And an elastic packing is interposed between the periphery of the upper end opening on the downstream side of the refrigerant circuit unit and the periphery of the lower end opening on the upstream side of the connecting duct, and the periphery of the upper end opening of the refrigerant circuit unit. A taper that increases in the direction of one side covered with the inspection plate is provided, and a taper that matches the periphery of the upper end opening of the refrigerant circuit unit is also provided in the periphery of the lower end opening of the connecting duct. Air conditioner for precise temperature control.   The air conditioner for precise temperature control according to claim 1, wherein a plurality of screw fixing brackets are fixed to the refrigerant circuit unit main body, and the inspection plate is screwed to the refrigerant circuit unit main body.   The condenser heat exchanger is constituted by a water pipe, a check plate portion where the inlet and outlet portions of the water pipe are located is cut out, and the cut out portion is detachably covered with another check plate. The air conditioner for precise temperature control according to claim 1 or 2.   The refrigerant pipe constituting the condenser has a substantially U-shape or a substantially U-shape rotated by 90 °, and the upper pipe is supported by a fixing bracket fixed to the refrigerant circuit unit main body. The air conditioner for precision temperature control in any one of Claims 1-3.   The air conditioner for precise temperature control according to any one of claims 1 to 4, wherein the first temperature sensor is a ribbon-shaped sensor in which temperature measuring resistors distributed at a plurality of points are connected in series.

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