JP6141089B2 - Cold / hot water supply system and air conditioner - Google Patents

Description

  The present invention relates to a cold / hot water supply system and the like.

  For example, in a building such as an office building, an air conditioner is provided as a heat load source in each room, and cold air is supplied to the air conditioner from a cold / hot heat source machine to heat or cool the target space. There is. Here, for example, a cold / hot heat source machine (hereinafter referred to as a heat source machine) is one that generates cold water or hot water in a heat exchanger using, for example, a heat pump refrigeration cycle. Cold / hot water refers to cold water or hot water generated by a heat source machine.

  In such a cold / hot water supply system, there is a system in which an air-cooled heat source machine and a water-cooled heat source machine are mixed. And the air-cooled heat source machine and the water-cooled heat source machine are each operated, and there exists what controls the flow of the cold / hot water in local water piping (for example, refer patent document 1).

  Moreover, in a system having a plurality of heat source units, there is a system that controls the number of heat source units to be operated by detecting the inlet water temperature (see, for example, Patent Document 2).

Japanese Patent Publication No. 63-027626 Japanese Patent No. 3479861

  In the system disclosed in Patent Document 1, for example, a cooling load and a heating load are mixed, and a cooling operation and a heating operation can be simultaneously performed for these loads. Here, a plurality of heat source units are installed, but when the load changes, the heat source unit performs simple control to switch the number of operating heat source units at the maximum frequency of the compressor. For this reason, control in consideration of power consumption is not performed, and COP (Coefficient Of Performance) has been deteriorated.

  In the system disclosed in Patent Document 2 described above, when the inlet water temperature changes, simple control is performed to switch the number of heat source units at the maximum frequency of the compressor, resulting in an increase in power consumption and poor COP. It was.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a cold / hot water supply system that maintains a high COP and improves the efficiency of the entire system.

A cold / hot water supply system according to the present invention includes two water pipes through which water flows, a compressor that compresses refrigerant, an air heat exchanger that performs heat exchange between the refrigerant and air, and water and refrigerant that flow through the water pipe. A plurality of air-cooled heat source units having a water heat exchanger for heat exchange and a plurality of air-cooled heat source units having a pressure adjusting means for adjusting the pressure of refrigerant flowing into the water heat exchanger and constituting a heat pump circuit A cold / hot water supply system connected to a water pipe along the flow of water to supply water by heating or cooling, the compressor, two water heat exchangers through which water in each water pipe passes, and pressure regulation A water-cooled heat source unit that constitutes a heat pump circuit with means, a temperature detection unit that detects the temperature of the water flowing through the water pipe, and the operation of the air-cooled heat source unit based on the temperature detected by the temperature detection unit Compressor in one or more air-cooled heat source machines Based on the driving frequency, COP further comprises a control unit that performs processing of switching the higher number of operating air-cooled heat source machine, controller, prior to operating the plurality of air-cooled heat source apparatus, a water cooling type heat source machine The water-cooled heat source machine is operated until the compressor reaches the maximum drive frequency, and control is performed to compensate for the missing heat quantity with one or a plurality of air-cooled heat source machines .

  According to the present invention, for an air-cooled heat source apparatus that is connected along the flow of water in the water pipe and heats or cools the water, the controller determines that the COP is higher when the number of operating units is switched. Since the process of switching the number is performed, one or a plurality of heat source devices can be operated and water having a desired temperature can be supplied to the load side while maintaining a high COP.

It is a figure which shows schematic structure of the cold / hot water supply system in Embodiment 1 of this invention. It is a figure which shows the structure of the water-cooling type heat source machine 11 which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the air-cooling type heat source machine 21 and 51 which concerns on Embodiment 1 of this invention. It is a figure which shows the flowchart of the processing operation of the control part 100 in Embodiment 1 of this invention. It is a figure which shows the relationship between several air-cooling-type heat-source equipment and COP.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a schematic configuration of a cold / hot water supply system according to Embodiment 1 of the present invention. As shown in FIG. 1, the cold / hot water supply system according to the first embodiment includes a water-cooled heat source unit 11, six air-cooled heat source units 21, 31, 41, 51, 61 and 71, a hot water pump 81, and a cold water pump. 82, a hot water pipe 83, a cold water pipe 84, temperature sensors 91 to 98, and a control unit 100.

  The hot water pump 81 pressurizes the water in the hot water pipe 83 serving as a water pipe and circulates the pipe. At this time, the water in the hot water pipe 83 is heated by the water-cooled heat source unit 11 or the like, thereby transferring heat to, for example, a space (load) to be heated. Then, heat is exchanged by a radiator (not shown) to heat the air in the space to be heated. Moreover, the cold water pump 82 pressurizes the water in the cold water piping 84 used as water piping, and circulates the inside of piping. At this time, the water in the cold water pipe 84 is cooled by the water-cooled heat source unit 11 or the like, thereby conveying cold heat to a space (load) to be cooled, for example. Then, heat is exchanged by a cooler (not shown) to cool the air in the cooling target space. Here, in the present embodiment, the water-cooled heat source unit 11 with good COP is positioned upstream of the air-cooled heat source units 21 to 71 with respect to the flow of water in the hot water pipe 83 and the cold water pipe 84. Arranged (connected). Moreover, it arrange | positions in order of the air-cooling type heat-source equipment 21,31,41 along the flow of the water of the hot water piping 83, and arrange | positions in order of the air-cooling type heat-source equipment 51,61,71 along the flow of the water of the cold-water piping 84. Suppose you are. Moreover, although the inside of the hot water piping 83 and the cold water piping 84 is demonstrated as water flowing, the liquid which flows through the piping is not limited to water. For example, it may be antifreeze or the like, or other liquid may flow.

  FIG. 2 is a diagram showing a configuration of the water-cooled heat source unit 11 according to Embodiment 1 of the present invention. In FIG. 2, the water-cooled heat source unit 11 includes a compressor 12, a water-cooled side condenser (heat radiator) 13, a throttling device 14, and a water-cooled side evaporator (cooler) 15 connected by piping to provide a heat pump circuit (refrigerant circuit). It is composed. The compressor 12 sucks the refrigerant, compresses it, and discharges it in a high temperature / high pressure state. The compressor 12 of the present embodiment is configured by an inverter compressor of a type that can adjust the refrigerant discharge amount by controlling the rotation speed (drive frequency) by an inverter circuit or the like, for example. The water-cooled condenser 13 having a water heat exchanger performs heat exchange between the water flowing through the hot water pipe 83 and the refrigerant. At this time, the refrigerant dissipates heat, for example, condenses and becomes a liquid refrigerant (condensed liquid). On the other hand, water is heated. Further, the expansion device 14 expands the refrigerant by reducing the pressure. For example, it is constituted by a flow rate control means such as an electronic expansion valve, for example, an expansion valve having a temperature sensing cylinder, a refrigerant flow rate adjustment means such as a capillary tube (capillary), or the like. The water-cooled side evaporator 15 having a water heat exchanger performs heat exchange between water flowing through the cold water pipe 84 and the refrigerant. At this time, the refrigerant absorbs heat, e.g., evaporates into a gaseous refrigerant (vaporizes and vaporizes). On the other hand, the water is cooled.

  FIG. 3 is a diagram showing the configuration of the air-cooled heat source devices 21 and 51 according to Embodiment 1 of the present invention. FIG. 3A shows an air-cooled heat source device 21. FIG. 3B shows an air-cooled heat source machine 51. Here, air cooling type heat source machines 21 and 51 will be described on behalf of air cooling type heat source machines 21 to 71.

  As shown in FIG. 3A, an air-cooled heat source unit 21 is a heat pump circuit in which a compressor 22, an air-cooling side condenser (radiator) 23, an expansion device 24, and an air-cooling side evaporator (cooler) 25 are connected by piping. Is configured. Moreover, it has the air blower 26. The compressor 22 is composed of an inverter compressor like the compressor 12, and compresses and discharges the refrigerant. Further, the expansion device 24 expands the refrigerant by reducing the pressure. The air-cooling side condenser (heat radiator) 23 is a water heat exchanger that exchanges heat between the water flowing through the hot water pipe 83 and the refrigerant, similarly to the water-cooling side condenser 13. The air-cooling side evaporator 25 is an air heat exchanger that exchanges heat between the air supplied from the blower 26 and the refrigerant. The blower 26 forms an air flow in order to promote heat exchange between the refrigerant passing through the air-cooling side evaporator 25 and air.

  In addition, as shown in FIG. 3B, the air-cooling heat source unit 51 is configured by connecting a compressor 52, an air-cooling side condenser 53, an expansion device 54, and an air-cooling side evaporator 55 to form a heat pump circuit. A blower 56 is also provided. The compressor 52 is composed of an inverter compressor like the compressor 12, and compresses and discharges the refrigerant. Further, the expansion device 54 decompresses the refrigerant to expand it. The air-cooling side evaporator 55 is a water heat exchanger that exchanges heat between the water flowing through the cold water pipe 84 and the refrigerant, like the water-cooling side evaporator 15. The air-cooling side condenser 23 is an air heat exchanger that exchanges heat between the air supplied from the blower 56 and the refrigerant. The blower 56 forms an air flow in order to promote heat exchange between the refrigerant passing through the air-cooling side condenser 53 and the air.

  The temperature sensors 91 to 98 are temperature detection means for detecting the temperature (temperature of hot water or cold water) of the hot water pipe 83 or the cold water pipe 84 at the respective installed positions. The temperature sensor 91 detects the temperature of the hot water pipe 83 between the water-cooled heat source device 11 and the air-cooled heat source device 21 (the temperature of hot water flowing out from the water-cooled heat source device 11). The temperature sensor 92 detects the temperature of the hot water pipe 83 between the air-cooled heat source device 21 and the air-cooled heat source device 31 (the temperature of hot water flowing out from the air-cooled heat source device 21). Further, the temperature sensor 93 detects the temperature of the hot water pipe 83 between the air-cooled heat source device 31 and the air-cooled heat source device 41 (the temperature of hot water flowing out from the air-cooled heat source device 31). The temperature sensor 94 detects the temperature of the hot water pipe 83 on the downstream side of the air-cooling heat source device 41 (the temperature of the hot water flowing out from the air-cooling heat source device 41).

  On the other hand, the temperature sensor 95 detects the temperature of the cold water pipe 84 between the water-cooled heat source device 11 and the air-cooled heat source device 51 (the temperature of the cold water flowing out from the water-cooled heat source device 11). The temperature sensor 96 detects the temperature of the chilled water pipe 84 between the air-cooled heat source device 51 and the air-cooled heat source device 61 (the temperature of the cold water flowing out from the air-cooled heat source device 51). Further, the temperature sensor 97 detects the temperature of the chilled water pipe 84 between the air-cooled heat source device 61 and the air-cooled heat source device 71 (the temperature of the cold water flowing out from the air-cooled heat source device 61). The temperature sensor 98 detects the temperature of the chilled water pipe 84 on the downstream side of the air-cooled heat source unit 71 (the temperature of the cold water flowing out from the air-cooled heat source unit 71).

  The control unit 100 controls the cold / hot water supply system. In the present embodiment, the determination of the start (start-up) of the operation of the air-cooled heat source units 21 to 71 is based on the temperature related to the detection of the temperature sensors 91 to 98, the drive frequency of the compressor of each heat source unit, and the like. Do. Here, in the present embodiment, the control unit 100 performs processing or the like based on the drive frequency of the compressor included in the signal sent from the heat source unit side. For example, the control unit 100 adds the compressor to each heat source unit. When instructing the driving frequency, the driving frequency according to the instruction may be used.

  FIG. 4 is a diagram showing a flowchart of the processing operation of the control unit 100 according to Embodiment 1 of the present invention. Next, the process of the control part 100 in Embodiment 1 is demonstrated. Here, although the process which concerns on a hot water side is demonstrated, the same process is performed also on the cold water side, and cold water of target water temperature can be supplied to the load side.

  When the cold / hot water supply system starts operation, the water-cooled heat source unit 11 located at the uppermost stream with respect to the flow of hot water starts operation. Then, it is determined whether or not the first predetermined time has passed (S1). If it is determined that the first predetermined time has elapsed, it is determined whether the temperature of the hot water has reached the target water temperature based on the detection of the temperature sensor 91 (S2). If it is determined that the target water temperature has been reached, the compressor 12 is driven at a drive frequency at which hot water at the target water temperature can be supplied (S10), and the process ends.

  If it is determined that the target water temperature has not been reached, it is determined whether or not the compressor 12 is driven at the maximum drive frequency (S3). If it is determined that the drive is not performed at the maximum drive frequency, the drive frequency is increased (S4), and the process returns to S1 to continue the process. For example, in the water-cooled heat source unit 11, the COP does not deteriorate even if the compressor 12 is driven to the maximum drive frequency. Therefore, in order to ensure the water temperature by operating the water-cooled heat source unit 11 as much as possible, the compressor 12 is driven to the maximum drive frequency.

  On the other hand, if it is determined that the compressor 12 is driven at the maximum driving frequency, the air cooling heat source devices 21 to 41 located on the downstream side of the hot water flow are started and controlled (S5), and the water temperature is reduced. Secure and supply. Here, first, the operation of the air-cooled heat source unit 21 located on the most upstream side in the air-cooled heat source unit is started. Then, it is determined whether or not the second predetermined time has passed (S6). Here, the second predetermined time may be the same time as the first predetermined time described above. If it is determined that the second predetermined time has elapsed, for example, it is determined whether the temperature of the hot water has reached the target water temperature based on the detection of the temperature sensor 92 on the downstream side of the air-cooling heat source machine 21 (S7). If it is determined that the target water temperature has been reached, the compressor 12 and the compressor 22 are driven at a driving frequency capable of supplying hot water at the target water temperature (S10), and the process is terminated. On the other hand, if it is determined that the target water temperature has not been reached, the drive frequency of the compressor 22 is increased (S8).

  FIG. 5 is a diagram showing the relationship between a plurality of air-cooled heat source machines and the COP. FIG. 3 shows an example of the relationship between the cooling capacity ratio (frequency ratio of the total compressor frequency of the eight heat source units to the rated frequency) and the system COP. Here, the COP is calculated with the power consumption of the compressor being 10% of the power consumption of the compressor relative to the rated compressor power consumption when the power consumption of the compressor is 100%.

  In the case of an air-cooled heat source machine, there is a driving frequency at which the COP becomes maximum at a driving frequency lower than the maximum driving frequency in the compressor. For example, in FIG. 3, the maximum COP in each operating number of operating air-cooled heat source devices (compressed compressors) is about 3.2, and has an upwardly convex curve. , There is an intersection between at least one more operating unit or one less operating unit. For this reason, for example, when the total compressor frequency related to the operation of a certain number of air-cooled heat source units and the total compressor frequency related to the operation of the number of air-cooled heat source units increased by one to the same number are increased by one. There is a case where the COP becomes higher (the same is true when one unit is reduced). Here, the driving frequency of the compressor (the driving frequency corresponding to the intersection in FIG. 3) that becomes the boundary for switching the number of operating air-cooled heat source units (the number of driving compressors) is the boundary frequency (the boundary frequency is the previous frequency) Depending on the number of operating units, each air-cooled heat source unit may differ)

  Then, after increasing the drive frequency in S8, it is determined whether the drive frequency is higher than the boundary frequency (S9). If it is determined that the boundary frequency is not exceeded, the process returns to S6 and continues. On the other hand, if it is determined that the boundary frequency is exceeded, the process returns to S5, and the operation start and control of the air-cooled heat source unit located further downstream are performed. As a result, the number of operating units of the air-cooled heat source machine can be switched at the drive frequency with the best COP. As described above, the processing is performed until the hot water flowing through the hot water pipe 83 reaches the target water temperature.

  As described above, according to the system of the present embodiment, in the operation of the air-cooled heat source devices 21 to 71 in which the maximum point of COP is lower than the maximum driving frequency of the compressor, the boundary frequency is exceeded. If it is determined that the number of operating units is switched and the driving with the higher COP is selected, the COP can be kept high. Further, in a system in which the water-cooled heat source device 11 and the air-cooled heat source devices 21 to 71 are mixed as in the present embodiment, the water-cooled heat source device 11 having excellent COP is placed on the most upstream side of the water flow. It is possible to maintain a higher COP by preferentially operating the vehicle so that it is positioned at the position. In this way, it is possible to supply water at a desired temperature while maintaining a high COP by controlling the operation of one or a plurality of heat source units.

Embodiment 2. FIG.
The cold / hot water supply system of Embodiment 1 mentioned above has seven heat source units, one water cooling type heat source unit 11 and six air cooling type heat source units 21 to 71, as shown in FIG. However, it does not limit the number of heat source devices to be configured. The present invention is applicable if a water-cooled heat source machine and a plurality of air-cooled heat source machines are connected in series to a hot water pipe (cold water pipe).

  Moreover, in Embodiment 1, although the temperature sensors 91-98 are installed in the outflow side of the water from each heat source machine, it is not limited to this. For example, it may be determined whether or not the target water temperature has been reached using the temperature associated with detection by the temperature sensors 94 and 98.

  And in Embodiment 1, although applied about the process in the case of increasing the operation number of an air-cooling type heat source machine, it does not limit to this, For example, the process (process which concerns on an operation stop) which reduces the operation number of an air-cooling type heat source machine ) Can also be applied.

  11 Water-cooled heat source machine, 12 Compressor, 13 Water-cooled side condenser, 14 Throttle device, 15 Water-cooled side evaporator, 21 Air-cooled heat source machine, 22 Compressor, 23 Air-cooled side condenser, 24 Throttle device, 25 Air-cooled side evaporation 26 Air blower, 31 Air-cooled heat source machine, 41 Air-cooled heat source machine, 51 Air-cooled heat source machine, 52 Compressor, 53 Air-cooled side condenser, 54 Throttle device, 55 Air-cooled side evaporator, 56 Blower, 61 Air-cooled heat source Machine, 71 air-cooled heat source machine, 81 hot water pump, 82 cold water pump, 83 hot water pipe, 84 cold water pipe, 91, 92, 93, 94, 95, 96, 97, 98 temperature sensor, 100 control unit.

Claims (3)

Two water pipes through which water flows,
Compressor for compressing refrigerant, air heat exchanger for exchanging heat between said refrigerant and air, water heat exchanger for exchanging heat between water flowing through said water pipe and said refrigerant, and refrigerant flowing into said water heat exchanger A plurality of air-cooled heat source devices that have a pressure adjusting means for adjusting the pressure of the heat pump circuit, and connect the plurality of air-cooled heat source devices to the water pipe along the flow of the water. A cold / hot water supply system for supplying water by heating or cooling,
A water-cooled heat source machine comprising a heat pump circuit having the compressor, the two water heat exchangers through which water in each water pipe passes, and the pressure adjusting means;
Temperature detecting means for detecting the temperature of water flowing through the water pipe;
The operation of the air-cooled heat source unit is controlled based on the temperature related to the detection by the temperature detecting means, and the air cooling with the higher COP is performed based on the driving frequency of the compressor in one or a plurality of the air-cooled heat source units. And a control unit that performs a process of switching to the number of operating heat source units .
The control unit operates the water-cooled heat source machine until the compressor of the water-cooled heat source machine reaches a maximum drive frequency before operating the plurality of air-cooled heat source machines, and the amount of heat that is insufficient is 1 or A cold / hot water supply system that performs control supplemented by a plurality of the air-cooled heat source devices . 2. The cold / hot water supply system according to claim 1 , wherein a plurality of the temperature detection units are provided, and the temperature of the water flowing out from each heat source unit is detected. An air conditioner that heats or cools a space to be air-conditioned with water heated or cooled by the cold / hot water supply system according to claim 1 or 2 .

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