Refrigeration system
Patent Information
- Application Number
- PCT/JP2025/008822
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2026-09-17
Smart Images
Figure JP2025008822_17092026_PF_FP_ABST
Abstract
Description
Refrigeration system
[0001] The present disclosure relates to a refrigeration system including a refrigerant circuit and a cooling device that cools a condenser of the refrigerant circuit.
[0002] Along with the recent rise in outside air temperature, the temperature of air passing through the condenser of the refrigerant circuit (hereinafter referred to as intake air temperature) has been showing an upward trend. When the intake air temperature is high, such as in summer, the condensation performance of the condenser decreases compared to normal conditions, leading to problems such as increased power consumption to satisfy the required capacity and frequent occurrence of operation peak cutting to reduce the load.
[0003] Accordingly, there has conventionally been a cooling device that improves the condensation performance of a condenser by lowering the intake air temperature through the cooling effect of sprinkling water onto the condenser. Cooling devices are classified into a direct sprinkling type that directly sprinkles water onto the condenser, and an indirect sprinkling type that indirectly sprinkles water onto the condenser. Indirect sprinkling cooling devices are considered effective for heat exchangers where direct sprinkling may cause corrosion, such as when the condenser is an aluminum heat exchanger.
[0004] For example, Patent Document 1 discloses an automatic alarm notification system including a refrigerant circuit and an indirect sprinkling cooling device. The cooling device of Patent Document 1 includes a water retention filter that is moistened by water dripped from above. In the cooling device of Patent Document 1, the water retention filter is arranged on the windward side of the condenser, and the temperature of the air after passing through the water retention filter, that is, the intake air temperature, is lowered by the latent heat generated when water vaporizes. The condenser is cooled by the air having a lowered temperature, thereby improving condensation performance. The cooling device of Patent Document 1 collects water discharged from the water retention filter, supplies the collected water to the water retention filter again, and circulates the water. The automatic alarm notification system of Patent Document 1 includes a mechanism for detecting the water circulation state in order to prevent the condenser from not being cooled due to stoppage of water circulation in the cooling device, and issues an alarm when a stoppage of water circulation is detected.
[0005] Japanese Unexamined Patent Publication No. 2016-90134
[0006] The automatic alarm notification system described in Patent Document 1 only detects the water circulation state and does not have a mechanism to detect states other than the water circulation state. Therefore, in the automatic alarm notification system of Patent Document 1, even if the cooling function of the cooling device does not work due to factors other than the cessation of water circulation, and the condenser is not cooled, this cannot be detected and no alarm is issued. For this reason, the automatic alarm notification system of Patent Document 1 has room for improvement as a technology to suppress the deterioration of condenser performance. Possible factors that cause a decrease in condensing performance include insufficient cooling of the condenser due to deterioration of the water retention filter of the cooling device or deterioration of the condenser itself. However, the automatic alarm notification system of Patent Document 1 does not consider monitoring the state of the water retention filter of the cooling device or the state of the condenser, and therefore cannot detect even if factors that cause a decrease in condensing performance occur.
[0007] This disclosure aims to solve the above-mentioned problems and provides a refrigeration system that can detect and trigger an alarm when factors causing a deterioration in condenser performance occur, based on the state of the water retention filter or the state of the condenser of the cooling device.
[0008] The refrigeration system according to this disclosure comprises a refrigerant circuit in which a compressor, condenser, pressure reducing device, and evaporator are sequentially connected by refrigerant piping and a refrigerant is circulated, and a cooling device positioned upstream of the condenser and having a water-retaining filter that holds water, which cools the condenser by lowering the temperature of the air after it has passed through the water-retaining filter by vaporization of water, and passing the cooled air through to the condenser, and further comprising a performance degradation factor monitoring unit that monitors the state of the water-retaining filter of the cooling device or the state of the condenser and detects whether or not a factor causing a performance degradation of the condenser has occurred, and an alarm device that issues an alarm when the performance degradation factor monitoring unit detects that a factor causing a performance degradation of the condenser has occurred.
[0009] The refrigeration system described herein can detect and trigger an alarm when factors causing a deterioration in condenser performance occur, based on the state of the water retention filter or the state of the condenser in the cooling device.
[0010] This is a schematic refrigerant circuit diagram showing an example of the configuration of a refrigeration system according to Embodiment 1. This is an explanatory diagram of the cooling device of the refrigeration system according to Embodiment 1. This is a block diagram showing the configuration related to alarm activation in the refrigeration system according to Embodiment 1. This is a flowchart showing the flow of filter maintenance alarm activation processing in the refrigeration system according to Embodiment 1. This is a diagram showing an example of the alarm activation cycle in the refrigeration system according to Embodiment 1. This is a block diagram showing the configuration related to alarm activation in a refrigeration system according to Embodiment 2. This is a flowchart showing the flow of filter clogging alarm activation processing in the refrigeration system according to Embodiment 2. This is a block diagram showing the configuration of a refrigeration system according to Embodiment 3. This is a flowchart showing the flow of filter water retention insufficiency alarm activation processing in the refrigeration system according to Embodiment 3. This is a block diagram showing the configuration related to alarm activation in a refrigeration system according to Embodiment 4. This is a flowchart showing the flow of condenser maintenance alarm activation processing in the refrigeration system according to Embodiment 4.
[0011] The following description details a refrigeration system according to an embodiment, with reference to the drawings. This disclosure is not limited to the following embodiments, and various modifications are possible without departing from the spirit of this disclosure.
[0012] Embodiment 1. Figure 1 is a schematic refrigerant circuit diagram showing an example of the configuration of a refrigeration system 100 according to Embodiment 1. The refrigeration system 100 comprises a refrigeration device 10 and a cooling device 30 for cooling the condenser 12 of the refrigeration device 10, which will be described later. The refrigeration device 10 comprises an outdoor unit 1 and an indoor unit 2. The outdoor unit 1 comprises a compressor 11, a condenser 12, a blower 12a, and a pressure reducing device 13. The indoor unit 2 comprises an evaporator 21. The compressor 11, the condenser 12, the pressure reducing device 13, and the evaporator 21 are sequentially connected by refrigerant piping 10a, forming a refrigerant circuit 10b through which the refrigerant circulates. The pressure reducing device 13 is located in the outdoor unit 1, but it may be located in the indoor unit 2, or in both the outdoor unit 1 and the indoor unit 2. Furthermore, Figure 1 shows an example where the indoor unit 2 is equipped with an evaporator 21 and the refrigeration system 10 is a refrigerator that cools the room. However, the refrigeration system 10 is not limited to a refrigerator, and can also be applied to air conditioners and other devices capable of both cooling and heating.
[0013] The compressor 11 draws in low-temperature, low-pressure gaseous refrigerant, compresses it, and discharges it as high-temperature, high-pressure gaseous refrigerant. The compressor 11 is a scroll type, rotary type, reciprocating type, or screw type compressor, and is an inverter compressor whose capacity can be controlled by an inverter. The refrigerant discharged from the compressor 11 flows to the condenser 12.
[0014] The condenser 12 performs heat exchange between the air supplied by the blower 12a and the refrigerant, cooling and condensing the refrigerant. The condenser 12 is, for example, a finned tube heat exchanger. The condenser 12 is, for example, an aluminum heat exchanger in which the fins and heat transfer tubes are formed of aluminum or an aluminum alloy. Note that the condenser 12 is not limited to an aluminum heat exchanger, and may also be a heat exchanger composed of copper. The refrigerant from the compressor 11 becomes a low-temperature, high-pressure liquid refrigerant in the condenser 12, and after flowing out of the condenser 12, it flows to the depressurization device 13.
[0015] The pressure reducing device 13 reduces the pressure of the liquid refrigerant from the condenser 12, causing it to expand. The pressure reducing device 13 is, for example, an electronic expansion valve with adjustable opening. In addition to an electronic expansion valve, the pressure reducing device 13 may also be a mechanical expansion valve with a diaphragm in the pressure-receiving part, a thermostatic expansion valve, a capillary tube, or any other type that performs a similar function. The liquid refrigerant reduced in pressure by the pressure reducing device 13 flows to the evaporator 21.
[0016] The evaporator 21 is, for example, a fin-tube heat exchanger, which exchanges heat between the air in the target space, such as an indoor space, supplied by a blower (not shown) including a fan, and the refrigerant from the pressure reducing device 13, thereby evaporating the refrigerant. In addition to being air-cooled, the evaporator 21 may also be a water-cooled heat exchanger, such as a plate heat exchanger. In this case, the evaporator 21 exchanges heat between the refrigerant and water supplied by a water pump (not shown), etc. The refrigerant that flows out of the evaporator 21 flows to the compressor 11.
[0017] During cooling operation, the refrigerant compressed by the compressor 11 becomes a high-temperature, high-pressure gaseous refrigerant and is sent to the condenser 12. The refrigerant flowing into the condenser 12 exchanges heat with the outside air transported by the blower 12a and liquefies as it releases heat. The liquefied refrigerant is depressurized by the depressurization device 13 to become a two-phase gas-liquid state and flows into the evaporator 21. The refrigerant flowing into the evaporator 21 exchanges heat with the air in the target space supplied by a blower (not shown) and gasifies as it absorbs heat, and is returned to the compressor 11. As described above, the refrigeration system 100 performs cooling operation by circulating the refrigerant through the refrigerant circuit 10b. The air in the target space is cooled by heat exchange with the refrigerant flowing into the evaporator 21, and the target space is cooled by sending cold air from the indoor unit 2 into the target space.
[0018] The refrigeration system 10 also includes a condensation temperature sensor 60 and an air temperature sensor 61. The condensation temperature sensor 60 is located in the condenser 12 and measures the condensation temperature of the condenser 12. The condensation temperature measured by the condensation temperature sensor 60 is input to the control device 40, which will be described later. The air temperature sensor 61 is located upwind of the condenser 12 in a location unaffected by indirect water spraying and measures the temperature of the air before it flows into the condenser 12 and passes through the condenser 12. The temperature of the air passing through the condenser 12 is the outside air temperature if the condenser 12 is installed outdoors. In the following explanation, the air temperature measured by the air temperature sensor 61 will be assumed to be the outside air temperature. The outside air temperature measured by the air temperature sensor 61 is input to the control device 40.
[0019] The condensation temperature and ambient temperature input to the control device 40 are used for controlling the refrigerant circuit 10b, etc. The control of the refrigerant circuit 10b based on the condensation temperature and ambient temperature is not related to the gist of Embodiment 1, so its explanation is omitted. The condensation temperature and ambient temperature are used in the performance degradation factor monitoring unit 41 of the embodiment described later, so the utilization of the condensation temperature and ambient temperature will be explained again in the embodiment described later.
[0020] The cooling system 30 includes an evaporative air cooling system 31, a water supply system 32, and a drainage bucket 33, among other things.
[0021] Figure 2 is an explanatory diagram of the cooling device 30 of the refrigeration system 100 according to Embodiment 1. In Figure 2, components such as the compressor 11, which are not necessary for the explanation of the cooling device 30, are omitted from the illustration. The cooling device 30 is an indirect water-spraying type cooling device and includes an evaporative air cooling device 31, a water supply device 32, a drain bucket 33, as well as a water recovery device 34 and a pump 35. In Figure 2, the direction indicated by the white arrow is considered the front of the evaporative air cooling device 31, and in the following explanation, the left-right direction in Figure 2 is considered the depth direction, and the direction perpendicular to the plane of Figure 2 is considered the width direction.
[0022] The evaporative air cooling device 31 is equipped with a water-retaining filter 31a that absorbs water dripped from the water supply device 32 and maintains a moist state. The water-retaining filter 31a is positioned on the windward side of the condenser 12 and is sized to cover the entire condenser 12 when viewed from the front. The water-retaining filter 31a is, for example, commonly known as a cooling pad and is made of processed wood chips, polyethylene, and glass fiber, and has been commercially available for a long time. As shown by the thin arrows, outside air passes through the water-retaining filter 31a, and the outside air that has passed through the water-retaining filter 31a flows into the condenser 12.
[0023] The water supply device 32 is positioned above the evaporative air cooling device 31 and supplies water to the upper surface of the evaporative air cooling device 31. The water supply device 32 has a length approximately the same as the width of the evaporative air cooling device 31, and for example, a pipe has multiple holes drilled in it, through which water is dripped or sprayed onto the upper surface of the evaporative air cooling device 31.
[0024] The drain bucket 33 is located below the evaporative air cooling device 31 and is a bucket that collects water that drips from the water supply device 32 to the water retention filter 31a, but is not absorbed by the water retention filter 31a and falls from the water retention filter 31a. The water collected in the drain bucket 33 is collected in the water recovery device 34 via the water distribution pipe 33a.
[0025] The water recovery device 34 is a device that recovers water drained from the evaporative air cooling device 31. The water recovery device 34 includes a water storage tank 34a for storing water, a float 34b that moves vertically according to the height of the liquid level in the water storage tank 34a, and a float valve 34c that opens and closes according to the position of the float 34b. Replenishment water, such as tap water, is supplied to the water recovery device 34 from a replenishment water pipe 34d.
[0026] The float valve 34c opens when the float 34b descends after the liquid level in the water storage tank 34a falls below a set height. When the float valve 34c is open, water is supplied to the water storage tank 34a from the replenishment water pipe 34d. When the replenishment water is supplied to the water storage tank 34a and the liquid level rises above the set height, the float 34b rises and the float valve 34c closes. When the float valve 34c is closed, the supply of water from the replenishment water pipe 34d is stopped.
[0027] Pump 35 pumps water from the water storage tank 34a of the water recovery device 34 and supplies it to the water supply device 32 via the water supply pipe 35a. Pump 35 is operated and controlled by signals from the control device 40, which will be described later. Pump 35 is connected to the control device 40 by an external contact signal output method. The signal output method from the control device 40 to the pump 35 is not limited to a contact method; it may also be a wired or wireless communication method, or an analog signal output method such as DC 4-20mA.
[0028] In the cooling device 30 with the above configuration, water in the water recovery device 34 is pumped up by the pump 35 and supplied from the water supply device 32 to the evaporative air cooling device 31 via the water supply pipe 35a. The water supplied to the evaporative air cooling device 31 is absorbed by the water retention filter 31a, and any water that is not absorbed by the water retention filter 31a and is drained from the water retention filter 31a is first collected in the drain bucket 33 and then recovered to the water recovery device 34 via the water distribution pipe 33a. The water recovered in the water recovery device 34 is pumped up again by the pump 35 and circulated within the cooling device 30 as described above.
[0029] As shown by the thin arrows in Figure 2, outside air passes through the water retention filter 31a. The cooling device 30 lowers the temperature of the outside air passing through the water retention filter 31a by the latent heat of vaporization of the water held in the water retention filter 31a, and cools the condenser 12 by passing the cooled air through to the condenser 12.
[0030] The refrigeration system 100 improves its cooling capacity by cooling the condenser 12 with the cooling device 30 in this manner, thereby improving the condensation performance of the condenser 12.
[0031] The refrigeration system 100 further includes a control device 40 that controls the entire refrigeration system 100, and an alarm device 50 that outputs an alarm when it detects the occurrence of a factor that reduces the condensing capacity of the condenser 12.
[0032] The control device 40 monitors for the occurrence of factors that degrade the performance of the condenser 12, and when it detects that a factor causing a performance degradation of the condenser 12 is occurring, it performs control such as outputting an alarm from the alarm device 50. This control will be explained in more detail later. The control device 40 also controls the refrigerant circuit 10b and the cooling device 30.
[0033] The control device 40 consists of a CPU (also called a Central Processing Unit, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or processor) that executes a program stored in dedicated hardware or memory.
[0034] If the control device 40 is dedicated hardware, it may be, for example, a single circuit, a composite circuit, an ASIC (application specific integrated circuit), an FPGA (field-programmable gate array), or a combination thereof. Each of the functional units realized by the control device 40 may be realized by individual hardware, or each functional unit may be realized by a single piece of hardware.
[0035] When the control device 40 is a CPU, each function performed by the control device 40 is realized by software, firmware, or a combination of software and firmware. The software and firmware are written as programs and stored in memory. The CPU realizes each function of the control device 40 by reading and executing the programs stored in memory. Here, the memory is a non-volatile or volatile semiconductor memory such as RAM, ROM, flash memory, EPROM, or EEPROM.
[0036] Furthermore, some of the functions of the control device 40 may be implemented using dedicated hardware, while other functions may be implemented using software or firmware.
[0037] The alarm device 50 is a device that automatically issues an alarm based on a command from the performance degradation factor monitoring unit 41 (see Figure 3 below) of the control device 40 when the occurrence of a performance degradation factor in the condenser 12 is detected by the performance degradation factor monitoring unit 41 (see Figure 3 below). The alarm device 50 includes at least one of the following: a display means such as an LED or monitor for visually notifying the alarm; a sound output means such as a speaker for audibly notifying the alarm; and a communication means for issuing an alarm to an external device. The external device is, for example, a mobile terminal of the administrator of the refrigeration system 100, or a monitoring device that remotely monitors the operating status of the refrigeration system 100.
[0038] Figure 3 is a block diagram showing the configuration related to alarm activation of the refrigeration system 100 according to Embodiment 1. The control device 40 has a performance degradation factor monitoring unit 41 that monitors the state of the water retention filter 31a or the state of the condenser 12 and detects whether or not a performance degradation factor of the condenser 12 has occurred. The performance degradation factor monitoring unit 41 in Embodiment 1 monitors the state of the water retention filter 31a and detects whether or not a performance degradation factor of the condenser 12 has occurred. In Embodiment 1, the state of the water retention filter 31a refers to whether or not maintenance of the water retention filter 31a is required. The monitoring of the state of the condenser 12 and the monitoring of whether or not a performance degradation factor of the condenser 12 has occurred will be explained in Embodiment 4. The performance degradation factor monitoring unit 41 is functionally configured by the CPU of the control device 40 and a control program stored in its memory.
[0039] The performance degradation factor monitoring unit 41 has a filter maintenance determination unit 41a that determines whether maintenance of the water retention filter 31a is necessary. Maintenance of the water retention filter 31a includes inspection or replacement of the water retention filter 31a. If the filter maintenance determination unit 41a determines that maintenance of the water retention filter 31a is necessary, the performance degradation factor monitoring unit 41 detects that a performance degradation factor has occurred in the condenser 12. If a performance degradation factor has occurred in the condenser 12, the performance degradation factor monitoring unit 41 issues an alarm from the alarm device 50. The refrigeration system 100 does not stop the operation of the refrigerant circuit 10b when a performance degradation factor has occurred in the condenser 12, but only issues an alarm.
[0040] If the water retention filter 31a deteriorates in vaporization performance due to long-term use, there is a concern that this may lead to a decrease in condensation performance. For this reason, the filter maintenance determination unit 41a determines whether maintenance of the water retention filter 31a is necessary based on the operating time of the refrigeration system 100. The filter maintenance determination unit 41a determines that maintenance of the water retention filter 31a is necessary if the operating time of the refrigeration system 100 has exceeded a preset operating threshold time.
[0041] Here, the filter maintenance determination unit 41a uses the operating time of the pump 35, the operating time of the compressor 11, or the number of years elapsed since the initial start of operation as the "operating time of the refrigeration system 100". More specifically, the filter maintenance determination unit 41a determines whether maintenance of the water retention filter 31a is necessary using the following three determination methods. The filter maintenance determination unit 41a determines that maintenance of the water retention filter 31a is necessary if any of the following patterns are met. The customer can freely change the setting to select any of the patterns.
[0042] (1) When the operating time of the pump 35 exceeds a predetermined first threshold time (for example, 25,000 hours (*1)) (2) When the operating time of the compressor 11 exceeds a predetermined second threshold time (for example, 25,000 hours (*1)) (3) When the number of years elapsed from the initial start of operation of the pump 35 or compressor 11 to the present exceeds a predetermined threshold number of years (for example, 5 years)
[0043] *1 The "25,000 hours" is the time defined in the maintenance and inspection guidelines of the Japan Refrigeration and Air Conditioning Industry Association. The first threshold time and the second threshold time are not limited to "25,000 hours," and the first threshold time and the second threshold time are not limited to the same time, but may be different.
[0044] Furthermore, the operating time of the pump (1) 35 and the operating time of the compressor (2) 11 are cumulative operating times counted from after the power of the refrigeration system 100 is turned on. In addition, the first operation start in (3) refers to the timing when the operation of the pump 35 or the compressor 11 is started for the first time after the power of the refrigeration system 100 is turned on. The first operation start in (3) may alternatively be, for example, the timing when the detection value of a water level sensor (not shown) that detects the liquid level position of the water storage tank 34a of the cooling device 30 becomes equal to or lower than a set value.
[0045] The filter maintenance determination unit 41a determines whether maintenance of the water retention filter 31a is necessary based on any one of the three patterns described above. Alternatively, the filter maintenance determination unit 41a may determine that maintenance of the water retention filter 31a is necessary when two of the three patterns or all of the three patterns described above are satisfied.
[0046] The numerical values of each operating time serving as the threshold for the above determination and each of the patterns described above are merely examples, and the settings can be changed in consideration of the operating conditions of the refrigeration system 100. Each operating time serving as the threshold for the above determination may be set by calculating the estimated deterioration period based on the material of the water retention filter 31a and the like.
[0047] When the performance degradation factor monitoring unit 41 determines that maintenance of the water retention filter 31a is necessary based on the operating time of the refrigeration system 100, it causes the alarm device 50 to issue an alarm indicating that a performance degradation factor of the condenser 12 has occurred. The alarm issued from the alarm device 50 only needs to be an alarm indicating at least that a performance degradation factor of the condenser 12 has occurred, but it is more preferable if it is an alarm that can identify what the performance degradation factor of the condenser 12 is. Therefore, the alarm device 50 according to the first embodiment issues a filter maintenance alarm indicating that maintenance of the water retention filter 31a is required.
[0048] Fig. 4 is a diagram showing a flowchart of the filter maintenance alarm issuing process in the refrigeration system 100 according to Embodiment 1. The issuing process in Fig. 4 is performed at each control interval. The filter maintenance determination unit 41a determines whether the operating time of the refrigeration system 100 has exceeded the operating threshold time (step S1). If the performance degradation factor monitoring unit 41 determines that the operating time of the refrigeration system 100 has not exceeded the operating threshold time, the issuing process is terminated.
[0049] When the performance degradation factor monitoring unit 41 determines that the operating time of the refrigeration system 100 has exceeded the operating threshold time, it causes the alarm device 50 to issue a filter maintenance alarm (step S2). Note that the refrigeration system 100 continues to operate even after the filter maintenance alarm is issued. The alarm device 50 may stop the alarm issuing when an alarm stop button (not shown) is pressed after the alarm is issued, or may stop the alarm issuing automatically when a preset alarm issuing time elapses from the start of the alarm issuing, or in other cases.
[0050] Fig. 5 is a diagram showing an example of an alarm issuing cycle in the refrigeration system 100 according to Embodiment 1. There may be cases where maintenance of the water-retaining filter 31a is not performed after the alarm is issued. For this reason, the alarm device 50 may be configured to issue an alarm at a preset issuing cycle as shown in Fig. 5, for example, after the first alarm is issued. This cycle is desirably set to a time shorter than the reference period required from the start of operation to the first alarm issuing. For example, when the reference period is 120 days, the issuing cycle is set to 60 days, for example.
[0051] [Effects of Embodiment 1] The refrigeration system 100 according to Embodiment 1 includes a refrigerant circuit 10b through which a compressor 11, a condenser 12, a pressure reducing device 13, and an evaporator 21 are sequentially connected by refrigerant piping 10a, allowing the refrigerant to circulate, and a cooling device 30. The cooling device 30 is located on the upwind side of the condenser 12 and has a water-retaining filter 31a that holds water. The cooling device 30 cools the condenser 12 by lowering the temperature of the air after it passes through the water-retaining filter 31a through the vaporization of water, and passing the cooled air through the condenser 12. The refrigeration system 100 includes a performance degradation factor monitoring unit 41 that monitors the state of the water-retaining filter 31a of the cooling device 30 and detects whether or not a performance degradation factor of the condenser 12 has occurred. The refrigeration system 100 includes an alarm device 50 that issues an alarm when the performance degradation factor monitoring unit 41 detects that a performance degradation factor of the condenser 12 has occurred.
[0052] With the above configuration, the refrigeration system 100 of Embodiment 1 can detect and issue an alarm when a factor causing a performance degradation of the condenser 12 occurs, based on the state of the water retention filter 31a of the cooling device 30, specifically, whether or not maintenance of the water retention filter 31a is required. Since the refrigeration system 100 issues an alarm when it detects the occurrence of a factor causing a performance degradation of the condenser 12, it can issue an alarm before the condensation performance deteriorates. By issuing an alarm before the condensation performance deteriorates, the refrigeration system 100 can prevent continued operation in a state of reduced condensation performance. Therefore, the refrigeration system 100 can maintain the functionality of the cooling device 30 and, consequently, prevent abnormal operation of the refrigeration device 10, thereby ensuring stable operation of both the cooling device 30 and the refrigeration device 10. Since the refrigeration system 100 issues an alarm automatically, it can reduce labor costs associated with inspection work.
[0053] The performance degradation factor monitoring unit 41 determines whether maintenance of the water retention filter 31a is necessary based on the operating time of the refrigeration system 100. If the performance degradation factor monitoring unit 41 determines that maintenance of the water retention filter 31a is necessary, it detects that a performance degradation factor has occurred in the condenser 12.
[0054] The performance degradation factor monitoring unit 41 determines whether maintenance of the water retention filter 31a is necessary using the operating time of the pump 35 of the cooling device 30. Specifically, the performance degradation factor monitoring unit 41 determines that maintenance of the water retention filter 31a is necessary when the operating time of the pump 35 exceeds a preset first threshold time.
[0055] Alternatively, the performance degradation monitoring unit 41 uses the operating time of the compressor 11 as the operating time of the refrigeration system 100 to determine whether maintenance of the water retention filter 31a is necessary. Specifically, the performance degradation monitoring unit 41 determines that maintenance of the water retention filter 31a is necessary when the operating time of the compressor 11 has exceeded a preset second threshold time.
[0056] Alternatively, the performance degradation monitoring unit 41 determines whether maintenance of the water retention filter 31a is necessary using the number of years elapsed since the initial operation of the pump 35 or compressor 11 of the cooling device 30 as the operating time of the refrigeration system 100. Specifically, the performance degradation monitoring unit 41 determines that maintenance of the water retention filter 31a is necessary when the elapsed time exceeds a predetermined threshold number of years.
[0057] With the above configuration, the refrigeration system 100 of Embodiment 1 can determine whether or not maintenance of the water retention filter 31a is required by using the operating time of the pump 35, the operating time of the compressor 11, or the number of years elapsed since the initial start of operation of the pump 35 or the compressor 11 as the operating time of the refrigeration system 100.
[0058] In the first embodiment, the refrigeration system 100 issues a filter maintenance alarm when it determines that maintenance of the water retention filter 31a is required.
[0059] With the above configuration, the refrigeration system 100 of Embodiment 1 can encourage maintenance of the water retention filter 31a. By encouraging maintenance of the water retention filter 31a, the refrigeration system 100 of Embodiment 1 can prevent a decrease in the cooling capacity of the cooling device 30 caused by the long-term use of the water retention filter 31a, and consequently suppress a decrease in condensation performance.
[0060] Embodiment 2. Figure 6 is a block diagram showing the configuration related to alarm activation in the refrigeration system 100 according to Embodiment 2. The refrigeration system 100 of Embodiment 2 differs from Embodiment 1 in that the performance degradation factor monitoring unit 41 is equipped with a filter clogging determination unit 41b. Although Figure 6 shows an example in which the performance degradation factor monitoring unit 41 is not equipped with the filter maintenance determination unit 41a of Embodiment 1, it may also be equipped with a filter maintenance determination unit 41a and a filter clogging determination unit 41b. The following description will focus on the configurations in Embodiment 2 that differ from Embodiment 1, and configurations not described in Embodiment 2 are the same as in Embodiment 1.
[0061] The performance degradation factor monitoring unit 41 monitors the state of the water retention filter 31a and detects whether or not a performance degradation factor for the condenser 12 has occurred. In Embodiment 2, the state of the water retention filter 31a refers to whether or not the water retention filter 31a is clogged. The performance degradation factor monitoring unit 41 has a filter clogging determination unit 41b that determines whether or not the water retention filter 31a is clogged. The performance degradation factor monitoring unit 41 detects that a performance degradation factor for the condenser 12 has occurred when the filter clogging determination unit 41b determines that the water retention filter 31a is clogged. If the water retention filter 31a becomes clogged due to long-term use and its air permeability deteriorates, there is a concern that this will lead to a decrease in condensation performance. The filter clogging determination unit 41b determines whether or not the water retention filter 31a is clogged, which is a cause of such a decrease in condensation performance.
[0062] The filter clogging determination unit 41b determines whether the water retention filter 31a is clogged based on the difference between the condensation temperature when the condenser 12 is not being cooled by the cooling device 30 and the ambient temperature (hereinafter referred to as the first difference), which is measured by the condensation temperature sensor 60. Specifically, the filter clogging determination unit 41b determines that the water retention filter 31a is clogged if the first difference remains above a preset first difference threshold for a first set time (for example, 10 minutes) or longer. When the condenser 12 is not being cooled by the cooling device 30, such as when the pump 35 is stopped or when the water supply by the water supply device 32 is stopped.
[0063] The first differential threshold is set to, for example, 3K. The first differential threshold may be further subdivided by parameters such as evaporation temperature or ambient temperature. Furthermore, the first differential threshold is not limited to the above value and can be set considering the operating conditions of the refrigeration system 100.
[0064] The performance degradation factor monitoring unit 41, if the water retention filter 31a is clogged, will issue an alarm from the alarm device 50 indicating that a performance degradation factor for the condenser 12 has occurred. The alarm issued by the alarm device 50 should at least indicate that a performance degradation factor for the condenser 12 has occurred, but it is even better if the alarm can identify what the performance degradation factor for the condenser 12 is. Therefore, the alarm device 50 in Embodiment 2 issues a filter clogging alarm indicating that the water retention filter 31a is clogged.
[0065] Figure 7 is a flowchart showing the flow of the filter clogging alarm activation process for the refrigeration system 100 according to Embodiment 2. The filter clogging determination unit 41b measures the condensation temperature when not cooling using the condensation temperature sensor 60 and the ambient air temperature using the air temperature sensor 61, and calculates a first difference (step S11). The filter clogging determination unit 41b determines whether the first difference is greater than or equal to the first difference threshold (step S12).
[0066] The filter clogging determination unit 41b terminates the alarm process if the first difference is not equal to or greater than the first difference threshold. If the first difference is equal to or greater than the first difference threshold, the filter clogging determination unit 41b then determines whether the state in which the first difference is equal to or greater than the first difference threshold has continued for a first set time or longer (step S13).
[0067] If the filter clogging determination unit 41b does not return to step S11 if the state in which the first difference is greater than or equal to the first difference threshold has not continued for a first set time or longer, the filter clogging determination unit 41b determines that the water retention filter 31a is clogged if the state in which the first difference is greater than or equal to the first difference threshold has continued for a first set time or longer. If the performance degradation factor monitoring unit 41 detects that the water retention filter 31a is clogged, it issues a filter clogging alarm from the alarm device 50 (step S14). The refrigeration system 100 continues to operate even after the filter clogging alarm is issued.
[0068] Furthermore, when determining whether or not the water retention filter 31a is clogged, the filter clogging determination unit 41b may use the saturation temperature calculated from the compressor discharge pressure value measured by a discharge pressure sensor (not shown) located at the compressor outlet as the condensation temperature. Alternatively, the filter clogging determination unit 41b may use the refrigerant temperature at the outlet of the condenser 12, measured by a condenser outlet sensor (not shown) located at the outlet of the condenser 12, instead of the condensation temperature. In other words, the filter clogging determination unit 41b may determine whether or not the water retention filter 31a is clogged based on a first difference, which is the difference between the condensation temperature or the refrigerant temperature at the condenser outlet when the condenser 12 is not being cooled by the cooling device 30, and the ambient temperature. For this reason, for example, if a water retention filter 31a clogging determination function is added to a refrigeration system 100 that already has a condenser outlet sensor, the refrigeration system 100 can use the measurement value of the existing condenser outlet sensor to determine whether or not the water retention filter 31a is clogged.
[0069] In the flowchart of Figure 7, the alarm activation process is performed at each control interval if the decision in step S12 or step S13 is NO. In the flowchart of Figure 7, if the decision in step S12 is YES, the alarm activation process is performed not at each control interval, but after waiting for a first set time, which is longer than the control interval, to elapse.
[0070] The alarm device 50 may stop sounding an alarm when a stop button (not shown) is pressed after the alarm sounds, or it may automatically stop sounding an alarm when a preset time has elapsed since the alarm started. Alternatively, the alarm device 50 may be configured to sound an alarm at a preset interval after the initial alarm sounds.
[0071] [Effects of Embodiment 2] In the refrigeration system 100 of Embodiment 2, the performance degradation factor monitoring unit 41 is equipped with a filter clogging determination unit 41b, which determines whether or not the water retention filter 31a is clogged. The filter clogging determination unit 41b determines whether or not the water retention filter 31a is clogged based on a first difference, which is the difference between the condensation temperature or refrigerant temperature at the condenser outlet when not cooling and the ambient temperature. If the water retention filter 31a is clogged, the performance degradation factor monitoring unit 41 detects that a performance degradation factor has occurred in the condenser 12. The alarm device 50 issues an alarm when the performance degradation factor monitoring unit 41 detects that a performance degradation factor has occurred in the condenser 12.
[0072] With the above configuration, the refrigeration system 100 of Embodiment 2 can detect and issue an alarm when a factor causing a decrease in the condensing performance of the condenser 12 occurs, based on the state of the water retention filter 31a, specifically whether or not the water retention filter 31a is clogged. Since the refrigeration system 100 issues an alarm when it detects the occurrence of a factor causing a decrease in the performance of the condenser 12, it can issue an alarm before the condensing performance reaches a state of decreased performance. By issuing an alarm before the condensing performance reaches a state of decreased performance, the refrigeration system 100 can prevent continued operation in a state of decreased condensing performance. Therefore, the refrigeration system 100 can maintain the functionality of the cooling device 30 and, consequently, prevent abnormal operation of the refrigeration device 10, thereby ensuring stable operation of both the cooling device 30 and the refrigeration device 10. Since the refrigeration system 100 issues an alarm automatically, it can reduce labor costs associated with inspection work.
[0073] In the second embodiment, the refrigeration system 100 issues a filter clogging alarm if the first difference remains above a preset first difference threshold for a first set time or longer.
[0074] With the above configuration, the refrigeration system 100 of Embodiment 2 can prompt maintenance such as replacement or cleaning of the water retention filter 31a. If the water retention filter 31a becomes clogged due to factors such as dust or moisture freezing, the condensation performance of the refrigeration system 100 will decrease regardless of whether or not cooling is performed by the cooling device 30. The refrigeration system 100 of Embodiment 2 can suppress the decrease in condensation performance caused by the progression of clogging of the water retention filter 31a by issuing a filter clogging alarm when the water retention filter 31a is clogged and prompting maintenance of the water retention filter 31a.
[0075] Embodiment 3. Figure 8 is a block diagram showing the configuration of the refrigeration system 100 according to Embodiment 3. The refrigeration system 100 of Embodiment 3 differs from Embodiments 1 and 2 in that the performance degradation factor monitoring unit 41 is equipped with a water retention deficiency determination unit 41c. Although Figure 8 shows an example in which the performance degradation factor monitoring unit 41 is not equipped with the filter maintenance determination unit 41a of Embodiment 1 and the filter clogging determination unit 41b of Embodiment 2, it is also possible to equip the unit with some or all of these determination units in addition to the water retention deficiency determination unit 41c. Furthermore, the refrigeration system 100 of Embodiment 3 is equipped with a condensation temperature sensor 60 similar to that of Embodiment 2 shown in Figure 6. The following description will focus on the configurations of Embodiment 3 that differ from Embodiments 1 and 2, while configurations not described in Embodiment 3 are the same as those of Embodiments 1 and 2.
[0076] The performance degradation factor monitoring unit 41 monitors the state of the water retention filter 31a and detects whether or not a performance degradation factor for the condenser 12 has occurred. In Embodiment 3, the state of the water retention filter 31a refers to whether or not there is insufficient water retention in the water retention filter 31a. The performance degradation factor monitoring unit 41 has a water retention deficiency determination unit 41c that determines whether or not there is insufficient water retention in the water retention filter 31a. If the water retention deficiency determination unit 41c determines that there is insufficient water retention in the water retention filter 31a, the performance degradation factor monitoring unit 41 detects that a performance degradation factor for the condenser 12 has occurred.
[0077] If the water retention filter 31a is insufficiently filled with water, the temperature of the air after passing through the water retention filter 31a will not decrease sufficiently, leading to insufficient cooling of the condenser 12 by the cooling device 30 and raising concerns about a decrease in condensation performance. The water retention deficiency determination unit 41c determines whether or not the water retention filter 31a is insufficiently filled with water, which can be a cause of such a decrease in condensation performance. Factors that can cause water retention deficiency in the water retention filter 31a include, for example, insufficient water supply from the water supply device 32 to the water retention filter 31a.
[0078] The water retention deficiency determination unit 41c determines whether the water retention filter 31a is deficient in water retention based on the condensation temperature measured by the condensation temperature sensor 60. The water retention deficiency determination unit 41c determines whether the water retention filter 31a is deficient in water retention based on the difference between the condensation temperature when the condenser 12 is cooled by the cooling device 30 and the condensation temperature when it is not cooled (hereinafter referred to as the second difference). Specifically, the water retention deficiency determination unit 41c determines that there is a water retention deficiency if the second difference remains below a preset second difference threshold for a second set time (for example, 10 minutes) or longer. The second difference can also be considered as the condensation performance improvement rate from the condensation temperature during cooling.
[0079] The second differential threshold is set to, for example, 2K. The second differential threshold may be further subdivided by parameters such as evaporation temperature or ambient temperature. Furthermore, the second differential threshold is not limited to the above value and can be changed considering the operating conditions of the refrigeration system 100.
[0080] The performance degradation factor monitoring unit 41 issues an alarm from the alarm device 50 if there is insufficient water retention in the water retention filter 31a, indicating that a performance degradation factor has occurred in the condenser 12. The alarm issued by the alarm device 50 should at least indicate that a performance degradation factor has occurred in the condenser 12, but it is even better if the alarm can identify what the performance degradation factor of the condenser 12 is. Therefore, the alarm device 50 in Embodiment 3 issues a filter water retention shortage alarm indicating that there is insufficient water retention in the water retention filter 31a.
[0081] Figure 9 is a flowchart showing the flow of the filter water retention insufficiency alarm activation process for the refrigeration system 100 according to Embodiment 3. The activation process in Figure 9 is performed at each control interval. The water retention insufficiency determination unit 41c measures the condensation temperature during cooling and non-cooling using the condensation temperature sensor 60 and calculates a second difference (step S21). The water retention insufficiency determination unit 41c determines whether the second difference is greater than or equal to the second difference threshold (step S22).
[0082] The water shortage determination unit 41c terminates the alarm process if the second difference is not equal to or greater than the second difference threshold. If the water shortage determination unit 41c is equal to or greater than the second difference threshold, it then determines whether the state in which the second difference is equal to or greater than the second difference threshold has continued for a second set time or longer (step S23).
[0083] The water retention deficiency determination unit 41c returns to step S21 if the state in which the second difference is greater than or equal to the second difference threshold has not continued for the second set time or longer. The water retention deficiency determination unit 41c determines that there is a water retention deficiency in the water retention filter 31a if the state in which the second difference is greater than or equal to the second difference threshold has continued for the second set time or longer. The performance degradation factor monitoring unit 41 issues a filter water retention deficiency alarm from the alarm device 50 if there is a water retention deficiency in the water retention filter 31a (step S24). The refrigeration system 100 continues to operate even after the filter water retention deficiency alarm is issued.
[0084] Furthermore, when determining whether the water retention insufficiency of the water retention filter 31a is insufficient, the water retention insufficiency determination unit 41c may use as the condensation temperature the saturation temperature calculated from the compressor discharge pressure value measured by a discharge pressure sensor (not shown) located at the compressor outlet. Alternatively, instead of the condensation temperature, the water retention insufficiency determination unit 41c may use the refrigerant temperature at the outlet of the condenser 12 measured by a condenser outlet sensor (not shown) located at the outlet of the condenser 12. In other words, the water retention insufficiency determination unit 41c may determine whether the water retention in the water retention filter 31a is insufficient based on a second difference, which is the difference between the condensation temperature when the condenser 12 is being cooled by the cooling device 30 and the condensation temperature when it is not being cooled, or a second difference, which is the difference between the refrigerant temperature at the condenser outlet when the condenser 12 is being cooled by the cooling device 30 and the refrigerant temperature at the condenser outlet when it is not being cooled. Therefore, if a refrigeration system 100 that already has a condenser outlet sensor is to be further equipped with a function to determine if the water retention filter 31a is insufficient, the refrigeration system 100 can use the measurement value from the existing condenser outlet sensor to determine if the water retention filter 31a is insufficient.
[0085] In the flowchart of Figure 9, the alarm activation process is performed at each control interval if the decision in step S22 or step S23 is NO. In the flowchart of Figure 9, if the decision in step S22 is YES, the alarm activation process is performed not at each control interval, but after waiting for a second set time, which is longer than the control interval, to elapse.
[0086] The alarm device 50 may stop sounding an alarm when a stop button (not shown) is pressed after the alarm sounds, or it may automatically stop sounding an alarm when a preset time has elapsed since the alarm started. Alternatively, the alarm device 50 may be configured to sound an alarm at a preset interval after the initial alarm sounds.
[0087] [Effects of Embodiment 3] In the refrigeration system 100 of Embodiment 3, the performance degradation factor monitoring unit 41 is equipped with a water retention deficiency determination unit 41c, which determines whether or not there is insufficient water retention in the water retention filter 31a as the state of the water retention filter 31a. The water retention deficiency determination unit 41c determines whether or not there is insufficient water retention in the water retention filter 31a based on a second difference, which is the difference between the condensation temperature during cooling and the condensation temperature when not cooling, or a second difference, which is the difference between the refrigerant temperature at the condenser outlet during cooling and the refrigerant temperature at the condenser outlet when not cooling. If there is insufficient water retention in the water retention filter 31a, the performance degradation factor monitoring unit 41 detects that a performance degradation factor has occurred in the condenser 12. The alarm device 50 issues an alarm when the performance degradation factor monitoring unit 41 detects that a performance degradation factor has occurred in the condenser 12.
[0088] With the above configuration, the refrigeration system 100 of Embodiment 3 can detect and issue an alarm when a factor causing a decrease in the condensing performance of the condenser 12 occurs, based on the state of the water retention filter 31a, specifically whether or not there is insufficient water retention in the water retention filter 31a. Since the refrigeration system 100 issues an alarm when it detects the occurrence of a factor causing a decrease in the performance of the condenser 12, it can issue an alarm before the condensing performance reaches a state of decreased performance. By issuing an alarm before the condensing performance reaches a state of decreased performance, the refrigeration system 100 can prevent continued operation in a state of decreased condensing performance. Therefore, the refrigeration system 100 can maintain the functionality of the cooling device 30 and, consequently, prevent abnormal operation of the refrigeration device 10, thereby ensuring stable operation of both the cooling device 30 and the refrigeration device 10. Since the refrigeration system 100 issues an alarm automatically, it can reduce labor costs associated with inspection work.
[0089] In the third embodiment, the refrigeration system 100 issues a filter water shortage alarm if the second difference remains above a preset second difference threshold for a second set time or longer.
[0090] With the above configuration, the refrigeration system 100 of Embodiment 3 can prompt the checking of the water retention state of the water retention filter 31a. If the water retention state of the water retention filter 31a deteriorates due to a malfunction of the water supply device 32 or the like, the refrigeration system 100 will not be able to sufficiently cool the condenser 12, and the condensation performance will deteriorate. The refrigeration system 100 of Embodiment 3 can suppress the deterioration of condensation performance caused by insufficient water retention in the water retention filter 31a by issuing a filter water retention shortage alarm when there is insufficient water retention in the water retention filter 31a and prompting the checking of the water retention state of the water retention filter 31a.
[0091] Embodiment 4. Figure 10 is a block diagram showing the configuration related to alarm activation in the refrigeration system 100 according to Embodiment 4. The refrigeration system 100 of Embodiment 4 differs from Embodiments 1 to 3 in that the performance degradation factor monitoring unit 41 is equipped with a condenser maintenance determination unit 41d. In Figure 10, an example is shown in which the performance degradation factor monitoring unit 41 is not equipped with the filter maintenance determination unit 41a of Embodiment 1, the filter clogging determination unit 41b of Embodiment 2, and the water retention deficiency determination unit 41c of Embodiment 3. However, it is also possible to equip the unit with some or all of these determination units in addition to the condenser maintenance determination unit 41d. The following description will focus on the configurations in Embodiment 4 that differ from Embodiments 1 to 3, and configurations not described in Embodiment 4 are the same as those in Embodiments 1 to 3.
[0092] The performance degradation factor monitoring unit 41 monitors whether or not performance degradation factors for the condenser 12 have occurred based on the state of the condenser 12. The state of the condenser 12 refers to whether or not maintenance of the condenser 12 is required. The performance degradation factor monitoring unit 41 has a condenser maintenance determination unit 41d that determines whether or not maintenance of the condenser 12 is required. If the condenser maintenance determination unit 41d determines that maintenance of the condenser 12 is required, the performance degradation factor monitoring unit 41 detects that a performance degradation factor for the condenser 12 has occurred. Maintenance of the condenser 12 includes inspection or replacement of the condenser 12.
[0093] Since the condenser 12 is located downwind of the cooling device 30, water from the cooling device 30 may adhere to the condenser 12 via the water retention filter 31a due to the installation clearance between the condenser 12 and the cooling device 30 or the influence of wind in the installation environment, potentially leading to corrosion of the condenser 12. For this reason, the condenser maintenance determination unit 41d determines whether maintenance of the condenser 12 is necessary based on the cooling time of the condenser 12 by the cooling device 30.
[0094] More specifically, the condenser maintenance determination unit 41d determines that maintenance of the condenser 12 is necessary if the cooling time exceeds a preset cooling threshold time. The cooling time can be any time during which the condenser 12 is being cooled by the cooling device 30. The cooling time can be, for example, the time during which the temperature difference between the temperature sensors installed on the upwind and downwind sides of the water retention filter 31a remains above a set temperature, or the operating time of the pump 35.
[0095] The cooling threshold time is set to 30,000 hours (= 5,000 hours x 6 years), as defined in the maintenance and inspection guidelines of the Japan Refrigeration and Air Conditioning Industry Association, for example. Note that the above value for the cooling threshold time is just an example and can be set considering the operating conditions of the refrigeration system 100. Alternatively, the cooling threshold time may be calculated and set based on the specifications and installation clearance of the cooling device 30.
[0096] If the performance degradation factor monitoring unit 41 determines that maintenance of the condenser 12 is necessary, it will issue an alarm from the alarm device 50 indicating that a performance degradation factor has occurred in the condenser 12. The alarm issued by the alarm device 50 should at least indicate that a performance degradation factor has occurred in the condenser 12, but it is even better if the alarm can identify what the performance degradation factor of the condenser 12 is. Therefore, the alarm device 50 in Embodiment 4 issues a condenser maintenance alarm indicating that maintenance of the condenser 12 is necessary.
[0097] Figure 11 is a flowchart showing the flow of the condenser maintenance alarm activation process in the refrigeration system 100 according to Embodiment 4. The activation process in Figure 11 is performed at each control interval. The condenser maintenance determination unit 41d determines whether the cooling time of the condenser 12 by the cooling device 30 has exceeded the cooling threshold time (step S31). If the performance degradation factor monitoring unit 41 determines that the cooling time has not exceeded the cooling threshold time, it terminates the activation process. If the performance degradation factor monitoring unit 41 determines that the cooling time has exceeded the cooling threshold time, it activates a condenser maintenance alarm from the alarm device 50 (step S32). The refrigeration system 100 continues to operate even after the condenser maintenance alarm is activated.
[0098] The alarm device 50 may stop sounding an alarm when a stop button (not shown) is pressed after the alarm sounds, or it may automatically stop sounding an alarm when a preset time has elapsed since the alarm started. Alternatively, the alarm device 50 may be configured to sound an alarm at a preset interval after the initial alarm sounds.
[0099] [Effects of Embodiment 4] In the refrigeration system 100 of Embodiment 4, the performance degradation factor monitoring unit 41 is equipped with a condenser maintenance determination unit 41d, which determines whether maintenance of the condenser 12 is necessary based on the state of the condenser 12. The performance degradation factor monitoring unit 41 determines whether maintenance of the condenser 12 is necessary based on the cooling time of the condenser 12 by the cooling device 30. If maintenance of the condenser 12 is necessary, the performance degradation factor monitoring unit 41 detects that a performance degradation factor of the condenser 12 has occurred. The alarm device 50 issues an alarm when the performance degradation factor monitoring unit 41 detects that a performance degradation factor of the condenser 12 has occurred.
[0100] With the above configuration, the refrigeration system 100 of Embodiment 4 can detect and issue an alarm when a factor causing a performance degradation of the condenser 12 occurs, based on the state of the condenser 12, specifically whether or not maintenance of the condenser 12 is required. Since the refrigeration system 100 issues an alarm when it detects the occurrence of a factor causing a performance degradation of the condenser 12, it can issue an alarm before the condensation performance deteriorates. By issuing an alarm before the condensation performance deteriorates, the refrigeration system 100 can prevent continued operation in a state of reduced condensation performance. Therefore, the refrigeration system 100 can prevent abnormal operation of the refrigeration device 10 and ensure stable operation of the refrigeration device 10. Since the refrigeration system 100 issues an alarm automatically, it can reduce labor costs associated with inspection work.
[0101] In the fourth embodiment, the refrigeration system 100 issues a condenser maintenance alarm when the cooling time exceeds a preset cooling threshold time.
[0102] With the above configuration, the refrigeration system 100 of Embodiment 4 can encourage maintenance of the condenser 12 and prevent the condenser 12 from corroding.
[0103] Furthermore, the threshold values in each of the above embodiments may be set to pre-defined values or changed arbitrarily by the customer.
[0104] In the above embodiments, examples were shown in which the performance degradation factor monitoring unit 41 is equipped with a determination unit separately. However, the performance degradation factor monitoring unit 41 may be configured to include some or all of the determination units of each embodiment. In this case, if the performance degradation factor monitoring unit 41 determines that a performance degradation factor has occurred in the condenser 12, the alarm device 50 will issue an alarm with a different type of alarm depending on the cause of the condensation performance degradation.
[0105] 1 Outdoor unit, 2 Indoor unit, 10 Refrigeration system, 10a Refrigerant piping, 10b Refrigerant circuit, 11 Compressor, 12 Condenser, 12a Blower, 13 Pressure reducing device, 21 Evaporator, 30 Cooling device, 31 Evaporative air cooling device, 31a Water retention filter, 32 Water supply device, 33 Drain bucket, 33a Water distribution pipe, 34 Water recovery device, 34a Water storage tank, 34b Float, 34c Float valve, 34d Makeup water pipe, 35 Pump, 35a Water supply pipe, 40 Control device, 41 Performance degradation factor monitoring unit, 41a Filter maintenance determination unit, 41b Filter clogging determination unit, 41c Insufficient water retention determination unit, 41d Condenser maintenance determination unit, 50 Alarm device, 60 Condensation temperature sensor, 61 Air temperature sensor, 100 Refrigeration system.
Claims
1. A refrigeration system comprising: a refrigerant circuit in which a compressor, condenser, pressure reducing device, and evaporator are sequentially connected by refrigerant piping and a refrigerant is circulated; and a cooling device disposed on the upstream side of the condenser and having a water-retaining filter that holds water, which lowers the temperature of the air after it has passed through the water-retaining filter by vaporizing the water, and cools the condenser by passing the cooled air through to the condenser, the refrigeration system comprising: a performance degradation factor monitoring unit that monitors the state of the water-retaining filter of the cooling device or the state of the condenser and detects whether or not a factor causing a performance degradation of the condenser has occurred; and an alarm device that issues an alarm when the performance degradation factor monitoring unit detects that a factor causing a performance degradation of the condenser has occurred.
2. The state of the water retention filter refers to the state of whether or not maintenance of the water retention filter is required, and the performance degradation factor monitoring unit detects that a performance degradation factor of the condenser has occurred when it determines that maintenance of the water retention filter is required based on the operating time of the refrigeration system.
3. The refrigeration system according to claim 2, wherein the cooling device comprises a pump for circulating the water, and the performance degradation factor monitoring unit determines that maintenance of the water retention filter is necessary when the operating time of the pump has exceeded a preset first threshold time.
4. The refrigeration system according to claim 2, wherein the performance degradation factor monitoring unit determines that maintenance of the water retention filter is necessary when the operating time of the compressor has exceeded a preset second threshold time.
5. The refrigeration system according to claim 2, wherein the cooling device comprises a pump for circulating the water, and the performance degradation factor monitoring unit determines that maintenance of the water retention filter is necessary when the number of years elapsed since the initial start of operation of the pump or the compressor exceeds a predetermined threshold number of years.
6. The state of the water retention filter refers to the state of whether or not the water retention filter is clogged, and the refrigeration system according to claim 1, wherein the performance degradation factor monitoring unit detects that a performance degradation factor for the condenser has occurred when it determines that the water retention filter is clogged based on a first difference which is the difference between the condensation temperature or refrigerant temperature at the condenser outlet when the condenser is not being cooled by the cooling device and the temperature of the air passing through the condenser.
7. The refrigeration system according to claim 6, wherein the performance degradation factor monitoring unit determines that the water retention filter is clogged if the first difference remains above a preset first difference threshold for a first set time or longer.
8. The state of the water retention filter is the state of whether or not there is insufficient water retention in the water retention filter, and the refrigeration system according to claim 1, wherein the performance degradation factor monitoring unit determines that there is insufficient water retention in the water retention filter based on a second difference which is the difference between the condensation temperature when the condenser is cooled by the cooling device and the condensation temperature when it is not cooled, or a second difference which is the difference between the refrigerant temperature at the condenser outlet when it is cooled and the refrigerant temperature at the condenser outlet when it is not cooled, and detects that a performance degradation factor for the condenser has occurred.
9. The refrigeration system according to claim 8, wherein the performance degradation factor monitoring unit determines that there is insufficient water retention in the water retention filter if the second difference remains above a preset second difference threshold for a second set time or longer.
10. The state of the condenser refers to the state of whether or not maintenance of the condenser is required, the cooling device comprises a pump for circulating the water, and the performance degradation factor monitoring unit detects that a performance degradation factor has occurred in the condenser when it determines that maintenance of the condenser is required based on the cooling time of the condenser by the cooling device.
11. The refrigeration system according to claim 10, wherein the performance degradation factor monitoring unit determines that maintenance of the condenser is necessary when the cooling time has elapsed beyond a preset cooling threshold time.
12. The refrigeration system according to any one of claims 1 to 11, wherein the alarm device, when the performance degradation factor monitoring unit detects that a performance degradation factor of the condenser has occurred, issues an alarm in a manner that differs depending on the performance degradation factor.