JP2011058663A - Refrigerating air-conditioning device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact refrigerating air-conditioning device of high efficiency by preventing biasing of oil and increase of a unit size, even in a refrigerating air-conditioning device composed of refrigerating cycles using three or more compressors. <P>SOLUTION: One refrigerating device is composed of the plurality of refrigerating cycles 2 having: the plurality of compressors 3; one common heat source-side heat exchanger 4 to which a plurality of refrigerant circuits are connected; a plurality of pressure reducing devices 5; and one common load-side heat exchanger 6 to which the plurality of refrigerant circuits can be connected. Each refrigerating cycle configures one refrigerant circuit by annularly connecting the compressor, the heat source-side heat exchanger, the pressure reducing device and the load-side heat exchanger. The plurality of refrigerating devices composed of the plurality of refrigerating cycles independent by each compressor are included, flow channels of heat source-side heat medium are connected in series to the heat source-side heat exchangers of the plurality of refrigerating devices, and flow channels of load-side heat medium are connected in series to the load-side heat exchangers of the plurality of refrigerating devices. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a refrigeration air conditioner, and more particularly, to a refrigeration air conditioner that supplies cold and hot heat to a load side by heating and cooling a liquid medium such as water and brine.

  A conventional refrigeration and air-conditioning apparatus for supplying cold / hot heat is equipped with two refrigerant circuits, and the water-side flow path is connected at the inlet and the outlet of the plate heat exchanger of the two refrigerant circuits. Is prevented from freezing (see, for example, Patent Document 1).

Japanese Patent Laying-Open No. 2007-187353 (first page, FIG. 1)

However, in the case of the conventional refrigeration and air-conditioning apparatus, if there are three or more compressors, the plate heat exchanger has to be made more complicated, and the unit size increases, resulting in an increase in cost. there were.
In addition, since the flow path of the heat exchanger divides the refrigerant side circuit into left and right parts, when one compressor stops, although it detects freezing by looking at the temperature after merging, it stops Since the existing system is completely bypassed, there is a problem that efficiency is lowered.

  The present invention has been made to solve such a problem, and even in a refrigeration air conditioner configured with a refrigeration cycle using three or more compressors, oil bias is prevented and the unit size is large. The purpose is to obtain a compact and highly efficient refrigeration air conditioner.

  The refrigerating and air-conditioning apparatus according to the present invention includes a plurality of compressors, a common heat source side heat exchanger to which a plurality of refrigerant circuits can be connected, a plurality of decompression devices, and a single refrigerant circuit that can be connected. One refrigeration apparatus is composed of a plurality of refrigeration cycles having an emergency load-side heat exchanger, and each refrigeration cycle includes a compressor, a heat source-side heat exchanger, a decompression device, and a load-side heat exchanger connected in a ring shape. A plurality of the refrigeration apparatuses that form a single refrigerant circuit and are configured with a plurality of independent refrigeration cycles for each compressor, and each of the heat source side heat exchangers of the heat source side heat exchangers of the plurality of refrigeration apparatuses The flow path is connected in series, and the flow path of the load side heat medium is connected in series to each load side heat exchanger of the plurality of refrigeration apparatuses.

The refrigerating and air-conditioning apparatus according to the present invention includes a plurality of compressors, a common heat source side heat exchanger to which a plurality of refrigerant circuits can be connected, a plurality of decompression devices, and a single refrigerant circuit that can be connected. A plurality of refrigeration cycles having a shared load-side heat exchanger constitutes one refrigeration device, and each refrigeration cycle includes a compressor, a heat source-side heat exchanger, a decompression device, and a load-side heat exchanger connected in a ring shape. A plurality of the refrigeration devices that are formed by a plurality of independent refrigeration cycles for each compressor are formed, and the plurality of refrigeration cycles are independent for each compressor. This is a circuit that returns the oil to the compressor for the amount of oil that has been removed, and since the oil does not decrease, the reliability increases, and the heat source side heat exchanger and load side heat exchanger have multiple refrigeration cycles. Because the number of heat exchangers has not increased There is an effect that it provides an apparatus compact installation mode.
In addition, the flow path of the heat source side heat medium is connected in series to each heat source side heat exchanger of the plurality of refrigeration apparatuses, and the load side heat medium is connected to each load side heat exchanger of the plurality of refrigeration apparatuses. Since the flow paths are connected in series, the heat load medium is lowered to a predetermined temperature, or the heat source medium is raised to a predetermined temperature, so that the temperature gradient is reduced to install one heat exchanger or in parallel. More efficient operation can be provided than when the temperature is lowered or raised to a predetermined temperature by the plurality of heat exchangers.

1 is a circuit diagram of a refrigeration air conditioner according to Embodiment 1 of the present invention. The schematic block diagram of the internal structure of the water heat exchanger of the freezing air conditioner. The circuit diagram of the refrigerating air-conditioning apparatus of Embodiment 2 of this invention.

Embodiment 1 FIG.
1 is a circuit diagram of a refrigerating and air-conditioning apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a schematic configuration diagram of the internal structure of a water heat exchanger of the refrigerating and air-conditioning apparatus.
As shown in FIG. 1, refrigeration cycles 2a, 2b, 2c, and 2d having the same circuit configuration and the same specifications are mounted in a heat source machine 1 that is a refrigeration air conditioner.
The refrigeration cycle 2a includes a compressor 3a, a water heat exchanger 4a that is a heat source side heat exchanger, a main expansion valve 5a that is a pressure reducing device, and a water heat exchanger 6a that is a load side heat exchanger, and is annularly formed. A connected refrigerant circuit is configured. The refrigeration cycle 2b includes a compressor 3b, a water heat exchanger 4a that is a heat source side heat exchanger, a main expansion valve 5b that is a pressure reducing device, and a water heat exchanger 6a that is a load side heat exchanger. An annularly connected refrigerant circuit is configured.
The two water heat exchangers 4a and 6a are shared by the two refrigeration cycles 2a and 2b.
These two refrigeration cycles 2a and 2b constitute one or a set of refrigeration apparatuses.

Further, the refrigeration cycle 2c includes a compressor 3c, a water heat exchanger 4c that is a heat source side heat exchanger, a main expansion valve 5c that is a pressure reducing device, and a water heat exchanger 6c that is a load side heat exchanger, An annularly connected refrigerant circuit is configured. The refrigeration cycle 2d includes a compressor 3d, a water heat exchanger 4c that is a heat source side heat exchanger, a main expansion valve 5d that is a pressure reducing device, and a water heat exchanger 6c that is a load side heat exchanger. An annularly connected refrigerant circuit is configured. The two water heat exchangers 4c and 6c are shared by the two refrigeration cycles 2c and 2d.
These two refrigeration cycles 2a and 2b constitute one or a set of refrigeration apparatuses.
Therefore, this Embodiment 1 is composed of two or two sets of refrigeration apparatuses.
Each of the refrigeration cycles 2a, 2b, 2c, and 2d is provided with one compressor 3a, 3b, 3c, and 3d.
In each of the annularly connected refrigerant circuits 2, the refrigerant flows in the order of the compressor 3, the water heat exchanger 4, the main expansion valve 5, the water heat exchanger 6, and the compressor 3.

The water heat exchangers 4a, 4c, 6a, and 6c are plate heat exchangers, and have a flow path of water, refrigerant 1, and refrigerant 2, which are heat source media, as shown in FIG. The circuit is configured to flow, and the heat source, the refrigerant 1 and the refrigerant 2 exchange heat. R410A, which is a pseudo azeotrope refrigerant, is used as the refrigerant of this refrigeration air conditioner.
The main expansion valves 5a to 5c are electronic expansion valves whose opening degree is variably controlled.
Cold water, which is a heat load medium, is transported by a cold water pump 11 provided outside the heat source unit 1, becomes a dotted channel in the heat source unit 1, and flows in the order of the water heat exchanger 6 a and the water heat exchanger 6 c. In these water heat exchangers 6a and 6c, the flow path is configured so that the refrigerant and the cold water are opposed to each other.
Moreover, the cooling water which is a heat source medium is conveyed by the cooling water pump 12 provided outside the heat source unit 1 and becomes a dotted line in the heat source unit 1, and the water heat exchanger 4c and the water heat exchanger 4a It flows in order. In these water heat exchangers 4a and 4c, the flow path is configured so that the refrigerant and the cold water are opposed to each other.

  The heat source device control device 13 measures the refrigerant pressure and temperature of the refrigeration cycle, and the temperature of the water temperature as the heat medium, and operates the compressor 3 based on the operation information and the operation content instructed by the user of the refrigeration air conditioner. Control each actuator such as stop, rotation speed, opening of main expansion valve 5 and the like.

Next, the operation of the refrigeration air conditioner according to Embodiment 1 of the present invention will be described.
In the refrigeration cycle 2a, the high-temperature and high-pressure gas refrigerant discharged from the compressor 3a flows into the water heat exchanger 4a that is a heat source side water heat exchanger, and condenses while dissipating heat in the water heat exchanger 4a that serves as a condenser.・ Liquefy.
The high-pressure liquid refrigerant exiting the water heat exchanger 4a flows into the main expansion valve 5a. The refrigerant in the two-phase state decompressed to a low pressure by the main expansion valve 5a absorbs heat while evaporating and gasifying in the water heat exchanger 6a which is a load side water heat exchanger serving as an evaporator. Some water is cooled to produce cold water. The refrigerant leaving the water heat exchanger 6a is sucked into the compressor 3a.
The operations of the refrigeration cycles 2b, 2c, and 2d are the same as those of the refrigeration cycle 2a.

Next, operation | movement of the cold water which flows into the water heat exchangers 6a and 6c which are load side heat exchangers is demonstrated.
The cold water is driven by a cold water pump 11. Low-temperature, for example, 7 ° C. cold water flows into a load-side device such as a fan coil, where the temperature of the cold water itself rises while supplying cold heat around the load-side device. Flows into 1.
The cold water that has flowed into the heat source unit 1 is cooled by the refrigerant in the water heat exchanger 6a and the temperature is lowered. For example, the cold water flows out to 9.5 ° C., and then flows into the water heat exchanger 6c. Here, the cold water is cooled by the refrigerant, and further drops in temperature, for example, reaches 7 ° C., flows out of the water heat exchanger 6 c, and flows out of the heat source unit 1. Thereafter, the cold water flows into the load side device again.

Next, operation | movement of the cooling water which flows into the water heat exchangers 4a and 4c which are heat source side heat exchangers is demonstrated.
The cooling water is driven by the cooling water pump 12. High-temperature, for example, 40 ° C. cooling water flows into a cooling device such as a cooling tower, where the temperature of the cooling water decreases while dissipating heat around the device such as air, and then flows into the heat source unit 1 after decreasing to 35 ° C., for example. To do.
The cooling water that has flowed into the heat source unit 1 is heated by the refrigerant in the water heat exchanger 4c to rise in temperature, for example, flows out at 37.5 ° C., and then flows into the water heat exchanger 4a. Here, the cooling water is heated by the refrigerant and further rises in temperature, for example, reaches 40 ° C., flows out of the water heat exchanger 4a, and flows out of the heat source unit 1. Thereafter, the cooling water again flows into the cooling device.

Normally, oil necessary for operation is stored in the compressor, but a small amount of oil circulates in the refrigeration cycle together with the refrigerant.
In the heat source unit 1 that is the refrigeration air-conditioning apparatus according to the first embodiment, each of the compressors 3a to 3d has one refrigerant circuit for the refrigeration cycles 2a to 2d, and the amount of oil that has flown out. This is a circuit in which oil returns to the compressor, and since the oil does not decrease, the reliability increases.

In addition, the refrigeration cycles 2a and 2b constituting the refrigerant circuit having the water heat exchangers 4a and 6a are independent, but the water heat exchangers 4a and 6a are plate-type heat exchangers, one water circuit and one refrigerant. Since it has two circuits and is configured to have a counter flow so that the refrigerant and the cold water flow opposite to each other and is shared by the two refrigeration cycles 2a and 2b, the number of water heat exchangers has not increased. A device with a compact installation form can be provided.
In addition, the refrigeration cycles 2c and 2d constituting the refrigerant circuit having the water heat exchangers 4c and 6c are also independent, but the water heat exchangers 4c and 6c have two refrigeration cycles 2c and 2d as described above. Since the number of water heat exchangers has not increased, the apparatus can be provided in a compact installation form.

Moreover, the cold water flow path 8a of the water heat exchanger 6a shared by the refrigeration cycles 2a and 2b and the cold water flow path 8b of the water heat exchanger 6c shared by the refrigeration cycles 2c and 2d are connected in series, and the heat Cold water as a load medium is conveyed by a cold water pump 11 provided outside the heat source device 1 and flows in order from the cold water flow path 8a on the upstream side to the cold water flow path 8b on the downstream side so that the cold water is lowered to a predetermined temperature. Since the temperature gradient is cooled to a small degree by dividing the temperature, the cooling operation is more efficient than the case of cooling to a predetermined temperature by one heat exchanger or two heat exchangers installed in parallel. Can be provided.
Further, the cooling water flow path 9a of the water heat exchanger 4c shared by the refrigeration cycles 2a and 2b and the cooling water flow path 9b of the water heat exchanger 4a shared by the refrigeration cycles 2c and 2d are connected in series, and the heat source Cooling water as a medium is conveyed by a cooling water pump 12 provided outside the heat source unit 1 and flows in order from the cooling water flow path 9a on the upstream side to the cooling water flow path 9b on the downstream side, and the cooling water reaches a predetermined temperature. Since the temperature gradient is heated by sharing it so as to increase the temperature, it is more efficient than the case where the heat exchanger is heated up to a predetermined temperature by one heat exchanger or two heat exchangers installed in parallel. A cooling operation can be provided.

When the compressors 3a to 3d are variable capacity compressors, the capacity of the compressor is compared with the temperature of the chilled water temperature sensor 7 and the target temperature. The total capacity is increased. Further, when the cold water temperature <the target temperature, control is performed to reduce the total capacity of the compressor.
In general, when a plurality of compressors are used in parallel for one water heat exchanger, it is necessary to operate the plurality of compressors with the same capacity in order to prevent oil bias.
In the heat source unit 1 that is the refrigeration air-conditioning apparatus of the first embodiment, two compressors 3a are provided for the water heat exchanger 4a of the heat source side heat exchanger or the water heat exchanger 6a that is the load side heat exchanger. Even if 3b is used, each of the compressors 3a and 3b has one refrigerant circuit for each of the refrigeration cycles 2a and 2b, so that there is no problem of preventing oil bias and compression. Capacity control is performed for each of the machines 3a or 3b, and fine capacity control can be performed. The same applies to the refrigeration cycles 2c and 2d.
Further, since the compressors 3a to 3d are configured with the refrigerant pipe diameter for each unit, the refrigerant flow rate does not become small even when the compressor operating capacity is small, so that operation with a smaller capacity is possible.
Furthermore, in the refrigeration cycle 2a, 2b or 2c, 2d, even when one of the two compressors fails, the refrigerant circuit is independent, so that operation with other normal compressors is possible. It is possible and emergency response can be made easily.

  Further, when the frequency of the commercial power source is different in the region where it is used, and the cooling capacity of the heat source unit is different, the heat source unit control device 13 determines the commercial power source from the power source waveform at the site where the heat source unit 1 is actually installed. The upper limit value of the capacity of the compressor is changed in order to match the cooling capacity ratio to the difference in frequency of the commercial power supply of the compressor used in the heat source unit 1. For example, by changing the upper limit value of the compressor capacity so that a commercial power supply frequency is 50 Hz and a cooling capacity of 100 KW, and a commercial power supply frequency is 60 Hz, a cooling capacity of 120 KW can be obtained. It is possible to easily cope with the cooling capacity of the compressor with respect to the frequency of different commercial power sources without changing the frequency.

Embodiment 2. FIG.
FIG. 3 is a circuit diagram of the refrigerating and air-conditioning apparatus according to Embodiment 2 of the present invention.
In the first embodiment, a set of two refrigeration cycles 2a and 2b constituting a refrigerant circuit having a water heat exchanger 4a that is a heat source side heat exchanger and a water heat exchanger 6a that is a load side heat exchanger. In the case of the refrigeration apparatus, two sets of refrigeration apparatuses are configured, but the second embodiment includes three sets of refrigeration apparatuses.
In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description of the overlapping components is omitted.
In the second embodiment, the refrigeration cycles 2a and 2b are configured as the first set of refrigeration devices, the refrigeration cycles 2c and 2d are configured as the second set of refrigeration devices, and the refrigeration cycles 2e and 2f are configured as the third set of refrigeration devices. .

The refrigeration cycle 2e includes a compressor 3e, a water heat exchanger 4e that is a heat source side heat exchanger, a main expansion valve 5e that is a pressure reducing device, and a water heat exchanger 6e that is a load side heat exchanger. A connected refrigerant circuit is configured. The refrigeration cycle 2f includes a compressor 3f, a water heat exchanger 4e that is a heat source side heat exchanger, a main expansion valve 5f that is a pressure reducing device, and a water heat exchanger 6e that is a load side heat exchanger. An annularly connected refrigerant circuit is configured.
The water heat exchanger 4e and the water heat exchanger 6e are also configured to have a counter flow so that the refrigerant and the cold water flow oppositely.
The two water heat exchangers 4e and 6e are shared by the two refrigeration cycles 2e and 2f.
Each of the refrigeration cycles 2a, 2b, 2c, 2d, 2e, and 2f includes one compressor 3a, 3b, 3c, 3d, 3e, and 3f.
In each of the annularly connected refrigerant circuits 2, the refrigerant flows in the order of the compressor 3, the water heat exchanger 4, the main expansion valve 5, the water heat exchanger 6, and the compressor 3.

Moreover, although the refrigerating cycle 2a, 2b which comprises the refrigerant circuit which has each water heat exchanger 4a, 6a is independent, since the water heat exchanger 4a, 6a is shared by the two refrigerating cycles 2a, 2b. Since the number of water heat exchangers has not increased, a compact installation apparatus can be provided.
Furthermore, although the refrigeration cycles 2c and 2d constituting the refrigerant circuit having the water heat exchangers 4c and 6c are also independent, the water heat exchangers 4c and 6c have two refrigeration cycles 2c and 2d as described above. Since the number of water heat exchangers has not increased, the apparatus can be provided in a compact installation form.
Furthermore, although the refrigeration cycles 2e and 2f constituting the refrigerant circuit having the respective water heat exchangers 4e and 6e are also independent, the water heat exchangers 4e and 6e have two refrigeration cycles 2e, Since it is shared by 2f, the number of water heat exchangers has not increased, so that a compact installation apparatus can be provided.

  Moreover, the cold water flow path 8a of the water heat exchanger 6a shared by the refrigeration cycles 2a and 2b, the cold water flow path 8b of the water heat exchanger 6c shared by the refrigeration cycles 2c and 2d, and the refrigeration cycles 2e and 2f The cold water flow path 8c of the shared water heat exchanger 6e is connected in series, and the cold water as the heat load medium is conveyed by the cold water pump 11 provided outside the heat source unit 1, and the upstream cold water flow path Since the cooling water flows in order from the cooling water flow path 8b on the downstream side from the flow path 8a to the cooling water flow path 8c on the downstream side, the cooling water is lowered to a predetermined temperature so as to cool the temperature gradient small. An efficient cooling operation can be provided as compared with the case of cooling to a predetermined temperature by three or three heat exchangers installed in parallel.

  In addition, the cooling water passage 9c of the water heat exchanger 4c shared by the refrigeration cycles 2a and 2b, the cold water passage 9b of the water heat exchanger 4a shared by the refrigeration cycles 2c and 2d, and the refrigeration cycles 2e and 2f The cooling water flow path 9a of the shared water heat exchanger 4e is connected in series, and the cooling water as the heat source medium is conveyed by the cooling water pump 12 provided outside the heat source unit 1, and the upstream cooling water flow Since the cooling water flows in order from the path 9a to the cooling water flow path 9c on the downstream side to the cooling water flow path 9c, and the cooling water is increased to a predetermined temperature, the temperature gradient is heated to be small. An efficient cooling operation can be provided as compared with the case where heating is performed to raise the temperature to a predetermined temperature by one heat exchanger or three heat exchangers installed in parallel.

  Also in the heat source machine 1 which is the refrigeration air-conditioning apparatus of the second embodiment, each of the compressors 3a to 3f has one refrigerant circuit of the refrigeration cycle 2a to 2f, and the amount of oil that has been discharged. This is a circuit in which oil returns to the compressor, and since oil does not decrease, the reliability increases.

  1 heat source machine, 2a-2f refrigeration cycle, 3a-3f compressor, 4a, 4c, 4e water heat exchanger, 5a-5f main expansion valve, 6a, 6c, 6e water heat exchanger, 7 cold water temperature sensor, 11 cold water Pump, 12 Cooling water pump, 13 Heat source machine control device.

Claims (3)

A plurality of compressors, a common heat source side heat exchanger to which a plurality of refrigerant circuits can be connected, a plurality of pressure reducing devices, and an emergency load side heat exchanger to which a plurality of refrigerant circuits can be connected A plurality of refrigeration cycles constitute one refrigeration device, and each refrigeration cycle is formed by connecting a compressor, a heat source side heat exchanger, a decompression device, and a load side heat exchanger in a ring to form one refrigerant circuit,
A plurality of the refrigeration devices configured with a plurality of independent refrigeration cycles for each compressor,
The flow path of the heat source side heat medium is connected in series with each heat source side heat exchanger of the plurality of refrigeration apparatuses, and the flow of the load side heat medium with respect to each load side heat exchanger of the plurality of refrigeration apparatuses A refrigerating and air-conditioning apparatus characterized by connecting paths in series.   The refrigerating and air-conditioning apparatus according to claim 1, wherein the compressors independent of each other in the plurality of refrigeration cycles have variable operation capacities, and each has a control device capable of controlling the operation capacities of the compressors.   The control device detects the frequency of the commercial power source and controls to change the upper limit value of the compressor capacity in order to match the capacity ratio with respect to the difference in the commercial power source frequency of each compressor in the refrigeration apparatus. The refrigerating and air-conditioning apparatus according to claim 2.

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