JPS629461Y2 - - Google Patents

Description

[Detailed description of the invention] This invention provides a pump operation control device that controls the operation of a cooling water pump that supplies cooling water in the water cooling system in air conditioning equipment, etc. that is equipped with a water cooling system that cools refrigerators, etc. It is related to

Conventionally, frequency converters, fluid couplings, eddy current couplings, or inverters have been used to control the rotational speed of rotating bodies such as blower fans and cooling water pumps driven by electric motors in air conditioning equipment and refrigeration systems. ing. Among these, control systems using fluid couplings and eddy current couplings have a large horsepower loss and low energy efficiency, and it is difficult to use large-capacity frequency converters and inverters.
The control method using a frequency converter also requires turning off the power to the motor and waiting until the fan, etc. has stopped, in order to prevent reverse drive of the motor due to inertial rotation of the blower fan or cooling water pump when changing the rotation speed. There are also problems that have been discussed as unavoidable.

A control method using a slipping clutch, which can easily be manufactured with a large capacity, has been proposed in order to control the rotational speed of large-capacity blower fans and cooling water pumps, etc. The horsepower loss due to heat generation is large, and the energy efficiency is not much different from fluid couplings or eddy current couplings.

As mentioned at the beginning, this idea achieves high energy efficiency by accurately controlling the driving rotation speed of the cooling water pump using a control method with low horsepower loss in air conditioning equipment equipped with a water cooling system. The present invention aims to provide a new pump operation control device for air conditioning equipment, etc., which achieves a high energy saving effect.

Regarding the illustrated embodiment, the configuration of the pump operation control device according to the invention will be explained first.
The first embodiment shown in FIG. 4 relates to an example in which this invention is implemented in an air conditioning facility as shown in FIG. In FIG. 1, C is an air-conditioned space where heating and cooling are performed, and in order to cool the inside of this air-conditioned space C, a turbo chiller 1 is used, and in order to heat the inside of this air-conditioned space C, a boiler 2 is used. Each is installed. Cold water from the centrifugal chiller 1 and hot water from the boiler 2 are selectively sent to the fan coil 4 of the fan coil unit 3,
Cool air or hot air is supplied to the air-conditioned space C via a line 6 by a fan 5 behind the fan coil 4. Parts of the water circulation path between the turbo chiller 1 and the fan coil unit 3 and the water circulation path between the boiler 2 and the fan coil unit 3 are common to each other. - In the water circulation path between the units 3, chilled water is supplied from a line 8 into which a chilled water pump 7 is inserted, to the fan coil 4 via an outgoing common line 9, and to the turbo chiller 1 via an incoming common line 10 and a line 11.
It is formed in such a way that water is returned to the Further, in the water circulation path between the boiler 2 and the fan coil unit 3, hot water is supplied to the fan coil 4 via the line 12 and the above-mentioned outbound common line 9, and the above-mentioned return common line 10 and the hot water pump 13 are inserted. The boiler 2 is configured so that water is returned to the boiler 2 through a line 14. Lines 8 and 1 above
2 each have an on-off valve 1 for selectively connecting each line 8, 12 to the outgoing common line 9.
5, 16 are provided, and the above-mentioned line 1
1 and 14 are respectively provided with on-off valves 17 and 18 for selectively connecting the return common line 10 to the respective lines 11 and 14. A bypass line 19 that bypasses the fan coil unit 3 is provided between the outbound common line 9 and the return common line 10.
Control valves 20 and 21 are inserted into the outgoing common line 9 and the bypass line 19 on the downstream side of the branch point of the bypass line 19, respectively, so that the opening degree can be changed and controlled. A part of the cold water or hot water sent through the outgoing common line 9 is allowed to flow into the incoming common line 10 without being electrically connected to the fan coil 4, and temperature control can be performed. The fan coil unit 3 is provided with a window 3a that opens to the outside air, and the air-conditioned space C is equipped with a ventilation fan 22, which connects the line 2 to the outside air.
A portion of the air discharged through line 23
A fan and a branch line 23a branched from
A structure is adopted in which the coil is returned to the inside of the coil unit 3.

Similarly, as shown in FIG. 1, a cooling tower 24 is provided.
Cooling water for the centrifugal chiller 1 is supplied between the centrifugal chiller 4 and the centrifugal chiller 1 through the outbound line 25 and the inbound line 26 to the cooling water pump 2 provided in the outbound line 25.
7 to circulate it. The pump operation control device according to the first embodiment shown in FIGS. 1-4 is configured as follows for controlling the operation of the cooling water pump 27 described above.

That is, first, as similarly shown in FIG. 1, the cooling water pump 27 described above is not directly driven by the motor 28 that constitutes its drive source, but the motor 28 and the cooling water pump 27
A transmission 29 is inserted and installed in the drive path between the motor 2 and the cooling water pump 27 through the transmission 29.
8.

The transmission 29 described above, as shown in FIG.
An input shaft 31 and an output shaft 32 that are parallel to each other are rotatably supported by the transmission case 30, and a pair of ball bearings 33 are loosely fitted to the input shaft 31 between the input shaft 31 and the output shaft 32. An idling gear 34 provided thereon and a transmission gear 3 fitted onto the output shaft 32
5 and the input shaft 31.
1 on the transmission gear 36 and the output shaft 32 provided by fitting into the
A second gear train is provided which meshes with an idling gear 38 loosely fitted through a pair of ball bearings 37. Both gears 3 in the first gear train
The relationship between the gear ratio between gears 4 and 35 and the gear ratio between both gears 36 and 38 in the second gear train is such that the idle gear 34 in the first gear train is coupled to the input shaft 31,
An input shaft 31 and an output shaft 32 via the first gear train.
When the rotational speed n ₁ obtained on the output shaft 32 is interlocked and connected between The rotation speed is set to be higher than the rotational speed n ₂ obtained by the output shaft 32 when the shaft 31 and the output shaft 32 are interlocked (n ₁ >n ₂ ).

The idler gear 34 in the first gear train is connected to the input shaft 3
1, a hydraulic clutch 39 as described below is disposed between the idler gear 34 and the input shaft 31. That is, a clutch housing 40 is fixed to the transmission gear 36 and is provided on the input shaft 31, and the boss extension 34a of the idler gear 34 and the clutch housing 40 extend into the clutch housing 40. One and the other friction elements 41 and 42 for a plurality of sheets are arranged alternately in each of the clutches 39 and 42, respectively.
A multi-disc hydraulic clutch 39, which is known per se, is constructed with free sliding support only in the axial direction. This hydraulic clutch 39 includes a piston 43 provided in a clutch housing 40, and a return spring 45 provided on the input shaft 31 with both ends received by a spring bearing ring 44 on the input shaft 31 and the piston 43. The piston 43, which is energized backward, is moved forward by supplying hydraulic oil to the oil chamber 46 behind the piston 43, and the friction elements 41, 42 are pressed against the pressure receiving plate 47 supported by the clutch housing 40. At the same time, by frictionally engaging the friction elements 41 and 42, the engagement is activated. Depending on the operation of the hydraulic clutch 39, the free rotating gear 34 is coupled to the input shaft 31, and the first gears 34, 35 are connected between the input shaft 31 and the output shaft 32.
The output shaft 32 is interlocked and connected through the rows, and the output shaft 32 is rotated at a relatively high speed.

As a coupling means for selectively coupling the idler gear 38 in the second gear train to the output shaft 32, the idler gear 38 is connected between both ball bearings 37.
An overrunning clutch 48 is disposed between the output shaft 32 and the output shaft 32. This overrunning
The clutch 48 is configured to engage when it is driven from the side of the idler gear 38, and therefore from the side of the input shaft 31. Therefore, the hydraulic clutch 39 is actuated and the first gears 34, 35
In a state where the output shaft 32 is rotated by the input shaft 31 through the column, the output shaft 32 rotates at the above-mentioned rotation speed n ₁ , while the idle gear 38 rotates at the lower rotation speed n ₂ The overrunning clutch 48 is driven relatively from the output shaft 32 side and does not engage the clutch. Therefore, the overrunning clutch 48 is configured to engage the clutch only when the hydraulic clutch 39 is in the inoperative state to couple the idler gear 38 to the output shaft 32, and the hydraulic clutch 39 is in the inactive state. When this happens, the input shaft 31 and the output shaft 32 are automatically interlocked and connected via the second gears 36 and 38, and the output shaft 32 is rotated at a relatively low speed.

In order to control the supply and discharge of hydraulic oil to and from the hydraulic clutch 39 in the transmission 29, a hydraulic circuit as shown in FIG. 3 is provided. This hydraulic circuit includes an electromagnetic switching valve 49 configured as a 3-port, 2-position valve as shown in the figure, and an oil tank 5 which also serves as a lower part of the transmission case 30.
The two ports on the primary side are connected to an oil supply circuit 52 that supplies hydraulic oil from zero to the hydraulic clutch 39 using a hydraulic pump 51, and an oil drain circuit 53 that returns hydraulic oil from the hydraulic clutch 39 to an oil tank 50. A solenoid switching valve 49 is provided. In the illustrated neutral position N, the electromagnetic switching valve 49 connects both the oil supply circuit 52 and the hydraulic clutch 39 to the oil drain circuit 53, disengaging the hydraulic clutch 39, and conversely returns to the operating position by energizing the solenoid SL. When moved to I, the oil supply circuit 52 is connected to the hydraulic clutch 39, the oil drain circuit 53 end is blocked, and the hydraulic clutch 39 is engaged. Therefore, in the neutral position N of the electromagnetic switching valve 49, the second row of gears 36 and 38 performs speed change transmission, and in the operating position I of the switching valve 49, the first row of gears 34 and 35 performs speed change transmission. will be carried out. In FIG. 3, reference numeral 54 denotes a relief valve that sets the hydraulic pressure applied to the hydraulic clutch 39 at the operating position I of the electromagnetic switching valve 49. In addition,
As shown in FIG. 2, the above-mentioned hydraulic pump 51 is installed on the outer surface of a case lid 30a that closes an opening at one end of the transmission case 30, and is driven by the input shaft 31. There is.

In order to control the position switching of the electromagnetic switching valve 49, the following electric control circuit is provided. That is, first, as shown in FIG. 1, the temperature of the cooling water at the outlet and the inlet of the cooling water in the centrifugal chiller 1 is measured and an electric signal corresponding to the water temperature is output. Temperature sensors 55, 56 are provided, which are connected into a control box 57 attached to the transmission 29. Within control box 57, temperature sensors 55 and 56 are connected to amplifiers 58 and 59, respectively, as shown in FIG.
The temperature sensor 60 is connected to an arithmetic unit 60 via the arithmetic unit 60, and the arithmetic unit 60 is configured to calculate the difference between the output signals of both temperature sensors 55 and 56. Arithmetic unit 6
The secondary side of 0 is connected to the positive input terminal of a comparator 62 via an amplifier 61. A power supply voltage Vcc can be set at the negative input terminal of the comparator 62 by appropriately dropping it with a variable resistor 63. Therefore, the comparator 62 detects that when the difference in temperature detected by the temperature sensors 55 and 56 becomes higher than the set value set by the variable resistor 63,
Outputs a high level signal.

On the other hand, the solenoid SL of the electromagnetic switching valve 49
is connected in parallel with the surge absorbing diode D, one end is connected to the power supply terminal, and the other end is grounded, and inserted into the control circuit shown in Fig. 4. , emitsuta grounding
An NPN transistor Tr is inserted. and,
The secondary side of the comparator 62 described above is connected to the base of the NPN transistor Tr, which is grounded via the pull-down resistor RP. Therefore, when the comparator 62 is outputting a high-level signal, the NPN transistor Tr is turned on, current is conducted to the solenoid SL, and the solenoid SL is energized and the electromagnetic switching valve 49 is turned on. takes the operating position I, and conversely, when the above signal is not output from the comparator 62,
The NPN transistor Tr is in the off state, the solenoid SL is demagnetized, and the electromagnetic switching valve 49 is in the neutral position N.

The set value of the temperature difference set in the comparator 62 in response to the difference in the temperatures detected by the two temperature sensors 55 and 56 is, for example, 6°C. When performing cooling operation of the illustrated air conditioner with such a temperature difference value set in the comparator 62, the water temperature difference between the cooling water inlet and outlet of the centrifugal chiller 1 is calculated based on the above-described configuration. is larger than the set value, the electromagnetic switching valve 49 takes the operating position I, and the transmission 29 performs speed change transmission by the first gears 34 and 35, so that the cooling water pump 27 is relatively When the engine is operated at a high rotational speed and the above-mentioned water temperature difference is smaller than the set value, the electromagnetic switching valve 49 takes the neutral position N, so that the second gear 3
Variable speed transmission is performed by the 6th and 38th rows, and the cooling water pump 27 is operated at a relatively low rotation speed. Therefore, when the water temperature difference between the cooling water inlet and outlet of the servo chiller 1 is large, a relatively large amount of cooling water is supplied to the servo chiller 1, and conversely, when the water temperature difference is small, a relatively large amount of cooling water is supplied to the servo chiller 1. A relatively small amount of cooling water will be supplied to the servo refrigerator 1. A small difference in water temperature between the inlet and outlet of the cooling water of the servo chiller 1 means that an excessive amount of cooling water is being supplied to the servo chiller 1. In such a case, by controlling the operating speed of the cooling water pump 27 to be lowered, wasteful power consumption in the cooling water pump 27 can be avoided.

In the air conditioning equipment shown in FIG. 1, a transmission 65 is provided between the motor 64 for driving the cold water pump 7 for cooling operation and the cold water pump 7, and a transmission 65 is provided for driving the hot water pump 13 for heating operation. A transmission 6 is connected between a driving motor 66 and the hot water pump 13.
Further, a transmission 69 is inserted between the fan motor 68 for driving the fan 5 of the fan coil unit 3 and the fan 5, and each of these transmissions 65, 67, and 69 has a Control boxes 70, 71, and 72 are provided to appropriately switch the gears of the transmissions 65, 67, and 69, thereby controlling the operation of the air conditioning equipment in a more energy-saving manner. That is, the control mechanism within the control box 70
The gear stage of the transmission 65 is appropriately switched according to the detected temperatures of temperature sensors 73 and 74 that detect the water temperature on the outlet side and inlet side of the coil unit 3, respectively, and a temperature sensor 75 that detects the temperature of the air-conditioned space C. , the control mechanism in the control box 71 controls the driving rotation speed of the cold water pump 7, and the temperature sensors 76A and 76B that detect the water temperature on the outlet side and the inlet side of the boiler 2, respectively, and the temperature of the air conditioned space C. The control mechanism in the control box 72 appropriately switches the gear stage of the transmission 67 according to the temperature detected by the temperature sensor 75, which detects the temperature, and controls the driving rotation speed of the hot water pump 13. According to the detected value of the temperature sensor 75, which detects the temperature of the fan 5, the gear position of the transmission 69 is appropriately changed and the driving rotation speed of the fan 5 is controlled.

Next, the second embodiment shown in FIG. 5 will be explained. This second embodiment is an example in which this invention is implemented in the refrigeration system of Showcase S installed in the store of a fresh food retailer. It depends. In the refrigeration system shown in FIG. 5, four refrigerators 77 are installed in parallel, and each refrigerator 77 has a fifth refrigerator.
As shown in the figure, one refrigerator 77 has a built-in compressor 79 that is driven by a motor 78 to compress refrigerant gas, and a condenser 80 that liquefies and condenses the compressed refrigerant gas by receiving water cooling. ing. The refrigerant circuit outside the refrigerator 77 is provided with an expansion valve 81 that expands and vaporizes the liquefied refrigerant, and a cooling coil 82 wound inside the case S, and the refrigerant flows through the cooling coil 82. It is then returned to the refrigerator 77. In FIG. 5, 83 is a cooling tower, and the cooling water cooled in the cooling tower 83 is sent to the condenser 80 of each refrigerator 77 by a cooling water pump 84 via a distribution valve 85. After the refrigerant is cooled, it is returned to the cooling tower 83 for cooling.

In such a refrigeration system, the above-mentioned cooling water pump 84 is not directly driven by the motor 86 for driving the pump 84, unlike the usual case, but is connected to the above-mentioned motor 86 and the cooling water pump 84. A transmission 87 is interposed between the water pumps 84, and the water pumps 84 are driven by a motor 86 via the transmission 87. The transmission 87 is configured in the same manner as the transmission 29 shown in FIG. 2, for example.
For the gear change, the control box 88
is provided.

A temperature sensor 8 is installed at the cooling water outlet of each refrigerator 77.
9A, 89B, 89C, and 89D are provided, and a temperature sensor 90 is also provided in the confluence path of the cooling water flowing out from all the refrigerators. water temperature is detected. Also, on the upstream side of the distribution valve 85,
A temperature sensor 91 that detects the temperature of cooling water supplied to the refrigerator 77 is also provided. These temperature sensors 89A-91 are connected into control box 88 as shown.

The control mechanism provided in the control box 88 shown in FIG. 5 is, for example, as shown in FIG. Depending on the difference between
If this difference is small, the transmission 87 is configured to switch gears toward a lower gear. In this case, the temperature of the cooling water exiting the refrigerator 77 that is compared with the temperature of the water entering the refrigerator 77 is, for example, each temperature detected by the temperature sensors 89A, 89B, 89C, and 89D, and the temperature detected by the temperature sensor 90. The value obtained by adding the value obtained by multiplying the temperature by 4 and dividing the result by 8 is used.

Based on the above, even in the second embodiment shown in FIG. By reducing the number of batteries, energy can be saved. The compressor 79 is also driven by the motor 78 via the transmission 93.

As is clear from the description of the embodiments above, this invention uses multiple rows of variable speeds in the drive path of the cooling water pump 27 or 84 by an electric motor in an air conditioner equipped with a water cooling system for water cooling a refrigerator or the like. A stepped transmission 29 or 87 is provided to obtain a plurality of gear ratios through alternative transmission of gear trains 34, 35 and 36, 38, and a cooling water outlet of a cooled part such as a refrigerator is provided. A temperature sensor for detecting water temperature is provided at each of the water inlets, and depending on the difference between the water temperature at the cooling water outlet and the water temperature at the cooling water inlet, if this difference is small, the driving rotation speed of the cooling water pump is adjusted. The gearbox is configured to change the gear stage of the transmission so as to reduce the amount of cooling water supplied to the refrigerator, etc., and to detect excess or insufficient amount of cooling water supplied to the refrigerator, etc. from the water temperature difference between the cooling water inlet and outlet of the refrigerator, etc. By detecting this and controlling the driving rotation speed of the cooling water pump in the direction that supplies the appropriate amount of cooling water, it suppresses the supply of excessive cooling water to refrigerators, etc., and reduces the energy consumption of the cooling water pump. It is designed to achieve energy conservation.

Cooling water pumps have the characteristic that the power consumption is proportional to the cube of the rotation speed, and even by reducing the rotation speed in a relatively small range, significant power savings can be achieved (reducing the rotation speed to 80%). (The power consumption would be approximately 50%.)Conversely, even with the proposed method of controlling the pump rotation speed stepwise rather than steplessly, it is possible to control the rotation speed within a relatively small range of, for example, 1:0.8. By changing the rotation speed within the range, precise temperature control can be achieved in an energy-saving way, and since the horsepower loss of a stepped transmission using a multi-speed gear train is extremely small, it is possible to achieve accurate temperature control. Extremely high energy saving effects can be achieved without any problems. Further, since the stepped transmission can be made to have a large capacity without any difficulty, there is no problem in controlling the drive of a large capacity cooling water pump.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of an air conditioning system equipped with the first embodiment of this invention, Fig. 2 is a longitudinal cross-sectional side view of the transmission in the first embodiment, and Fig. 3 is a diagram of the transmission in the first embodiment. FIG. 4 is a block diagram and circuit diagram of the electric control circuit in the first embodiment; FIG. 5 is a system diagram of a refrigeration system equipped with the second embodiment of this invention. . C...Air conditioned space, 1...Turbo chiller, 3...
Fan coil unit, 24... Cooling tower, 25... Outbound line, 26... Return line, 27... Cooling water pump, 28... Motor, 2
9...Transmission, 31...Input shaft, 32...Output shaft, 34...Idle gear, 35...Transmission gear, 36
... Transmission gear, 38 ... Idle gear, 39 ... Hydraulic clutch, 48 ... Overrunning clutch, 49 ... Solenoid switching valve, 51 ... Hydraulic pump,
SL... Solenoid, 55, 56... Temperature sensor, 57... Control box, 58, 59... Amplifier, 60... Arithmetic unit, 62... Comparator, 63...
Variable resistor, Tr...NPN transistor, S...
Showcase, 77... Refrigerator, 79... Compressor, 80... Condenser, 81... Expansion valve, 82... Cooling coil, 83... Cooling tower, 84... Cooling water pump, 85... Distribution valve,
86...Motor, 87...Transmission, 88...Control box, 89A, 89B, 89C, 89D...
Temperature sensor, 90... Temperature sensor, 91...
Temperature sensor.

Claims (1)

[Scope of utility model registration request] In air conditioning equipment, etc. equipped with a water cooling system that cools refrigerators, etc., it is possible to obtain multiple speed ratios by selective transmission of multiple speed change gear trains in the drive path of the cooling water pump by an electric motor. In addition, a temperature sensor for detecting water temperature is provided at the cooling water outlet and the cooling water inlet of a cooled part such as a refrigerator, and the water temperature at the cooling water outlet and the water temperature at the cooling water inlet are provided. A pump operation control device for air conditioning equipment, etc., configured to change the gear stage of the transmission so as to reduce the driving rotation speed of the cooling water pump if the difference is small.