A system for cooling dairy animals

Abstract

A system for cooling dairy animals in a barn, comprising one or more cooling devices for blowing air and / or spraying water, a sensor system for monitoring one or more environmental parameters in the barn, including temperature, and a control unit. The control unit is configured to receive input from the sensor system regarding the one or more environmental parameters during a night-time period and determine if the input fulfils a night-time cooling criterion. The control unit is then configured to select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion, and control the one or more cooling devices during the daytime period according to the selected daytime cooling mode. The disclosure further includes a control unit for such a cooling system, and a computer implemented method for cooling dairy animals.

Description

[0001] A SYSTEM FOR COOLING DAIRY ANIMALS

[0002] TECHNICAL FIELD

[0003] The invention relates to a system, control unit and method for cooling dairy animals in a barn.

[0004] BACKGROUND

[0005] Dairy animals are susceptible to heat stress in hot and humid environments. Heat stress can cause a decline in milk production, reduced fertility, and increased risk of illness or death. Cooling methods such as fans, misters, sprinklers, or air conditioners can help reduce the risk of heat stress in dairy animals. However, indiscriminate use of cooling devices can be inefficient and costly.

[0006] WO 2008039150 A1 describes such a system, where the thermal load of the animals is reduced by controlling a cooling means based on the measured temperature and / or temperature and humidity index (THI) in the surroundings of the animals. Therefore, the cooling means can be used more efficiently and selectively when there is an increased risk of heat stress.

[0007] To improve a system for cooling of dairy animals, it is sought to provide a solution which uses electricity and water in an even more efficient way. Therefore, there is a need for a system that makes efficient use of such resources, while providing cooling to the animals to reduce the risk of heat stress.

[0008] SUMMARY

[0009] It is an object of the invention to provide a system for cooling dairy animals, alleviating shortcomings of prior solutions.

[0010] According to one aspect of the invention, there is provided a system for cooling dairy animals in a barn. The dairy animals may be e.g. dairy cows, but the system is useful for other dairy animals susceptible to heat stress, and also to other (non-dairy) livestock animals where there is a risk for heat stress. The system comprises one or more cooling devices for blowing air and / or spraying water over the animals, a sensor system for monitoring one or more environmental parameters in the barn, including temperature, and a control unit. The control unit is configured to receive input from the sensor system regarding the one or more environmental parameters during a night-time period and determine if the input fulfils a night- time cooling criterion. The control unit is then configured to select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion, and control the one or more cooling devices during the daytime period according to the selected daytime cooling mode.

[0011] The solution is based on the realization that dairy animals can handle periods of high thermal load. Typically, the temperature of the body of the animal lags the temperature of the surroundings, giving a certain resilience against heat stress. It is also realized that the animals may be able to recover during night-time, and that the cooling system can be improved by taking the recovery during night-time into account. By monitoring the environmental parameters (including temperature) during night-time, the appropriate daytime cooling mode for a subsequent daytime period can be selected. The daytime cooling mode can then be selected based on whether the environmental conditions during night-time are sufficient to reduce the temperature of the animal such an extent that it has a low risk of developing heat stress, or not.

[0012] The night-time cooling criterion may comprise determining if the one or more environmental parameters during the night-time period falls below a night-time threshold. Thus, it can be determined that sufficient cooling of the animal during the night-time period is achieved. Alternatively, or additionally, the night-time cooling criterion may comprise determining if the environmental parameter integrated during the night-time period falls below a night-time threshold, or if a mean value of the environmental parameter over the night-time period falls below a night-time threshold.

[0013] The control unit may be configured to select a first daytime cooling mode if the night-time cooling criterion is fulfilled, the first daytime cooling mode excluding spraying water with the one or more cooling devices, and to select a second daytime cooling mode if the night-time cooling criterion is not fulfilled, the second daytime cooling mode comprising an option of spraying water with the one or more cooling devices. Thereby two daytime cooling modes are provided, one where water is or may be used to cool the animals, and another where water is not used to cool the animals. Thus, the water consumption of the cooling system may be reduced if the night-time cooling is sufficiently high. This is particularly beneficial in areas where water is a scarce resource. The first daytime cooling mode may thus be a resource saving ventilation mode, and the second daytime cooling mode may be a powerful animal cooling mode, according to which water spraying is used if needed. The first and second daytime cooling mode may comprise blowing air, wherein the second daytime cooling mode has a higher maximum air blowing setting than the first daytime cooling mode. Thus, the overall energy consumption of the cooling system may be reduced, based on the fulfilment of the night-time cooling criterion.

[0014] The control unit may further be configured to receive input from the sensor regarding the one or more environmental parameters during the daytime period and selectively activate the one or more cooling devices according to the selected first and second cooling modes in response to the one or more sensed environmental parameters.

[0015] Thus, during the daytime period, the cooling devices may be actively controlled according to the selected cooling mode, in response to the sensed environmental parameters, including temperature. They can thus be switched on or off, or to increase or decrease the cooling effect in accordance with the selected cooling mode.

[0016] The control unit may be configured to selectively activate the one or more cooling devices according to the selected first and second cooling modes in response to an integration or mean of the one or more sensed environmental parameters during a predetermined period of time, the predetermined period of time being in the range of 1-6 hours, preferably 2-4 hours.

[0017] Thus, during the daytime period, the selected first and second cooling modes may be actively controlled according to the selected cooling mode, in response to the integration or mean of the sensed environmental parameters, including temperature. This gives a certain smoothening of the response of the system to the environmental parameters.

[0018] The sensor system may comprise sensors for monitoring temperature and humidity, so the one or more environmental parameters include temperature and humidity. The one or more environmental parameters may be a temperature and humidity index (THI) calculated from the monitored temperature and humidity. It has been shown that temperature and humidity is a good indicator of the severity of risk of heat stress in animals.

[0019] The control unit may be configured to automatically determine the daytime period and the night-time period based on a daily variation of the sensed one or more environmental parameters collected over a period of one or more days. Alternatively, the control unit may be configured to receive input from a user to determine the daytime period and the night-time period. Thereby daytime and night-time periods are manually or automatically set in relation to a clock, or automatically identified by the control unit based on collected data. According to another aspect the invention there is provided a control unit for a cooling system, the system comprising: one or more cooling devices for blowing air and / or spraying water over the animals, and a sensor system for monitoring one or more environmental parameters in the barn, including temperature.

[0020] The control unit is configured to: receive input from the sensor system regarding the one or more environmental parameters during a night-time period and determine if the input fulfils a night-time cooling criterion; select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion; and control the one or more cooling devices during the daytime period according to the selected daytime cooling mode.

[0021] The control unit provides the benefits described earlier and can be configured to provide the additional benefits disclosed herein.

[0022] According to yet another aspect the invention there is provided a computer implemented method for cooling dairy animals in a barn using one or more cooling devices for blowing air and / or spraying water, the method comprising: monitoring one or more environmental parameters in the barn, including temperature; receiving input regarding the one or more environmental parameters during a nighttime period and determining if the input fulfils a night-time cooling criterion; selecting a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion; and controlling one or more cooling devices during the daytime period according to the selected daytime cooling mode.

[0023] FIGURES

[0024] Fig. 1 shows a system for cooling dairy animals in a barn.

[0025] Fig. 2 shows a graph of variations over time indicating potential risk for heat stress. Fig. 3 shows a block diagram of a method for cooling dairy animals in a barn.

[0026] DETAILED DESCRIPTION

[0027] This disclosure relates to devices, systems, and methods for cooling dairy animals in a barn. Examples according to the claimed solutions will now be described in more details, with reference to the drawings.

[0028] Fig. 1 shows a system 100 for cooling dairy animals 101 in at least a part of a barn 102. The system comprises several cooling devices 103 arranged in the part of the barn. The cooling devices are typically fans with water spraying (misting) functionality. The cooling devices 103 may be individually controlled, or arranged and controlled in groups 104, 105, 106, for providing cooling to animals in different parts of the barn. Thus, the cooling devices are positioned to blow air and / or spray water over animals in the barn. The fan speed of such a cooling fan and the water spraying of such a water spraying device can be individually controlled. Generally, the cooling effect on animals in the barn is higher at higher fan speeds and with water spraying, due to evaporation of the water and removal of the water vapour.

[0029] The cooling system further comprises a sensor system 107 for monitoring one or more environmental parameters in the barn, including temperature. The sensor system thus includes a temperature sensor. According to an example the sensor system comprises at least one temperature sensor, and at least one humidity sensor. The cooling system further comprises a control unit 108. The control unit 108 is configured to receive input from the sensor system 107 regarding the one or more environmental parameters in the barn, i.e. temperature, and optionally humidity. Further temperature, humidity sensors, and sensors for other environmental parameters (e.g. wind, solar load, etc.) may be arranged in various parts of the barn, or outside the barn, and connected to the control unit to make sure that the conditions to which the animals are exposed are properly monitored and considered. The sensor system is connected to the control unit using wired or wireless connection. The control unit is configured to process input data and control the cooling devices based on input data, scheduling, user input, etc. The control unit therefore comprises components such as a processing unit, memory and I / O units, e.g. for communication over known communication protocols and for input by a user. It may be configured as a discrete unit, implemented as part of a computer, or in a cloud computing system. The cooling devices are connected to the control unit using wired or wireless connection 109. Thus, input from the sensor system 107 regarding the one or more environmental parameters in the barn is collected and processed in the control unit, which then output control signals used to control the cooling devices 103, individually or in groups. One group 104 of cooling devices may e.g. be arranged in the feeding area, close to a feed table 110 where feed is provided to the animals through a feed fence.

[0030] The control unit is configured to receive temperature input from the sensor system during a night-time period (i.e. typically a period from dusk to dawn, when the sun is not up). The night-time period may be defined by a user or may be automatically determined in the control unit by other means. During this night-time period the control unit is configured to determine if the input from the sensor system fulfils a night-time cooling criterion. This is typically that the temperature falls below a predetermined threshold, or that the temperature integrated over the night-time period falls below a predetermined threshold.

[0031] The control unit is then configured to select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion, and control the one or more cooling devices during the daytime period according to the selected daytime cooling mode. Cooling mode is a term used to describe a mode of operation of the cooling devices.

[0032] Turning to Fig. 2, this night-time cooling criterion is exemplified by a graph of the temperature T versus time t, over a period of several days (24 h periods). The temperature in the barn is shown as the line 201. Instead of temperature, T and line 201 could represent the combination of temperature and humidity in the form of a temperature and humidity index (THI), or even a heat load index (HLI), which in addition to temperature and humidity also considers solar load and wind speed. The risk of an animal obtaining heat stress is illustrated as by the line 202. Night-time periods 203 and 205 are shown around midnight (Oh and 24 h, respectively), and daytime periods 204 and 206 are indicated after each night-time period. This example shows the risk of an animal obtaining heat stress if there is no active cooling available.

[0033] As shown in the graph, the temperature T varies over time and typically falls during nighttime. A threshold TH indicates a level of temperature where the night-time temperature is low enough to support sufficient cooling of the animals. As shown, before Oh the risk 202 of an animal obtaining heat stress is relatively high. The temperature T during the first night-time period 203 does not fall below the threshold TH, and thus the night-time cooling effect is not sufficient to remove all of the animal’s accumulated heat since the previous day. Because of this, the risk 202 of an animal suffering from heat stress is relatively high already when the subsequent daytime period 204 starts. As shown the risk 202 of the animal suffering from heat stress increases during the daytime period 204 to a high level. During the following night-time period 205, the temperature 201 drops below the threshold TH, and as shown the risk 202 of the animal suffering from heat stress is reduced to a relatively low level. This has the effect that, even if the temperature increases during the subsequent daytime period 206, the risk 202 of the animal suffering from heat stress is still not very high.

[0034] Hence, the night-time cooling criterion determines that the cooling during the night-time is sufficient to reduce at least part of the accumulated heat of the animals from the day before, so that the risk of the animals suffering from heat stress the following day is reduced. This night-time cooling criterion may be that the temperature (or THI, or HLI, or other environmental parameters including temperature) falls below the threshold TH. Alternatively night-time cooling criterion may be that the temperature integrated, 207, during the night-time period falls below a night-time threshold, or that a mean value of the temperature (or THI, or HLI, or other environmental parameters including temperature) over the night-time period falls below a night-time threshold.

[0035] Based on whether the night-time cooling criterion is fulfilled or not, it has been realized that the cooling mode for the subsequent daytime period can be selected from at least a first “resource saving” cooling mode if the night-time cooling criterion is fulfilled, and a second “powerful” cooling mode if the night-time cooling criterion is not fulfilled, The cooling system is thereafter controlled during the subsequent daytime period according to the selected daytime cooling mode.

[0036] The first “resource saving” daytime cooling mode is typically a cooling mode which does not involve spraying of water. It may be referred to as a “ventilation mode”. Further, the first daytime cooling mode involves a relatively low speed of the fans used to ventilate the barn. According to the first daytime cooling mode the fan speed may be fixed, controlled according to a predefined schedule, or temperature controlled based on input from the sensor system.

[0037] The second “powerful” cooling mode is a cooling mode with comprises the option of spraying water with one or more cooling devices. The second daytime cooling mode also has a higher maximum air blowing setting than the first daytime cooling mode. Because of the option of water spraying and higher air blowing capability, the cooling mode is effective in reducing the risk of heat stress, when there is an increased risk of animals developing heat stress. When using the second cooling mode the control unit receives input from the sensor system 107 and controls the water spraying (selective activation - on / off, volume of water per time, etc), and the fans (selective activation - on / off, regulating speed etc) according to the programmed second cooling mode. The control unit thus continuously or intermittently receives input from the sensor system during the daytime period and selectively activates the cooling devices according to the selected first and second cooling modes in response to the one or more sensed environmental parameters. Typically, the cooling devices are controlled according to the selected cooling mode, in response to an average of the environmental parameters received by the control unit during a period of 1-6 hours.

[0038] Thereby two daytime cooling modes are provided, one where water is used to cool the animals, and another where water is not used to cool the animals, i.e. a ventilation mode. Thus, the water consumption of the cooling system may be reduced if the night-time cooling is sufficiently high. This is particularly beneficial in areas where water is a scarce resource. Also, the overall energy consumption may be reduced. In addition to the first and second daytime cooling modes there may be additional cooling modes for other specific purposes or circumstances.

[0039] Based on the temperature during night-time the cooling system does not need to provide the more powerful cooling using water spraying (misting) even if the next day turns out to be warm. The second and more powerful daytime cooling mode (combination of high air speed of the fans and spraying of water) is activated if the average night-time temperature is above a set value, or if the night-time temperature does not fall below a set value. If it is determined that the average night-time temperature drops below the set value, the first daytime cooling mode is selected for the next day, whereby fans switch to a ventilation mode (low to moderate air speed) where the water spraying is not active. If the next day turns out to be very hot, the user may still activate the more powerful second cooling mode manually on the controller. The user may set the time slot for the night-time period and can set the threshold to be used to determine the night-time cooling criterion.

[0040] In Fig. 3 a block diagram of a method 300 for cooling dairy animals in a barn is presented. The method is typically implemented in a control unit or other computer, as described above, and provides a computer implemented method for cooling dairy animals in a barn using one or more cooling devices for blowing air and / or spraying water. The method comprises monitoring 301 one or more environmental parameters in the barn, including temperature, and receiving, input regarding the one or more environmental parameters during a night-time period. During the night-time the cooling devices may be operated, 302, according to a nighttime cooling mode including ventilation using the cooling devices, if necessary. According to the night-time cooling mode the fan speed may be fixed, controlled according to a predefined schedule, or temperature controlled based on input from the sensor system. Based on the input regarding the one or more environmental parameters during the nighttime period, it is determined 303 if the input fulfils a night-time cooling criterion. The nighttime cooling criterion is whether the measured environmental parameters indicate that the cooling during night-time has been sufficient to reduce the accumulated heat stress risk, as previously described. The daytime cooling mode 304, 305 for a subsequent daytime period is selected based on fulfilment of the night-time cooling criterion, and the one or more cooling devices are controlled 306, 307 during the daytime period according to the selected daytime cooling mode.

[0041] According to the first daytime cooling mode 304 the cooling devices are controlled during the subsequent daytime period, according to the “resource saving” daytime cooling mode, for ventilation, 306, of the barn using fans. According to the second daytime cooling mode 305 the cooling devices are controlled during the subsequent daytime period, according to the “powerful” daytime cooling mode, including water spraying (misting) and high air flow from the cooling devices.

[0042] During the first and second daytime cooling mode the cooling devices are controlled according to the respective cooling mode and input 308, 309 regarding the one or more environmental parameters during the day.

[0043] The preferred forms of the invention described above are to be used as illustration only and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention, as defined by the claims.

Claims

CLAIMS1. A system (100) for cooling dairy animals in a barn, comprising: one or more cooling devices (103) for blowing air and / or spraying water; a sensor system (107) for monitoring one or more environmental parameters in the barn, including temperature; and a control unit (108) configured to:• receive input from the sensor system regarding the one or more environmental parameters during a night-time period and determine if the input fulfils a night-time cooling criterion;• select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion; and• control the one or more cooling devices during the daytime period according to the selected daytime cooling mode.

2. The system according to claim 1 wherein the night-time cooling criterion comprises determining if the one or more environmental parameters during the night-time period falls below a night-time threshold.

3. The system according to claim 1 wherein the night-time cooling criterion comprises determining if the environmental parameter integrated during the night-time period falls below a night-time threshold, or if a mean value of the environmental parameter over the night-time period falls below a night-time threshold.

4. The system according to any one of the preceding claims wherein the control unit is configured to: select a first daytime cooling mode if the night-time cooling criterion is fulfilled, the first daytime cooling mode excluding spraying water with the one or more cooling devices; and select a second daytime cooling mode if the night-time cooling criterion is not fulfilled, the second daytime cooling mode comprising spraying water with the one or more cooling devices.

5. The system according to claim 4 wherein the first and second daytime cooling mode comprise blowing air, and wherein the second daytime cooling mode has a higher maximum air blowing setting than the first daytime cooling mode.

6. The system according to claim 4 or 5 wherein the control unit is further configured to receive input from the sensor regarding the one or more environmental parameters during the daytime period and selectively activate the one or more cooling devices according to the selected first and second cooling modes in response to the one or more sensed environmental parameters.

7. The system according to claim 6 wherein the wherein the control unit is configured to selectively activate the one or more cooling devices according to the selected first and second cooling modes in response to an integration or mean of the one or more sensed environmental parameters during a predetermined period of time, the predetermined period of time being in the range of 1-6 hours, preferably 2-4 hours.

8. The system according to any one of the preceding claims wherein the sensor system comprises sensors for monitoring temperature and humidity, and wherein the one or more environmental parameters include temperature and humidity.

9. The system according to claim 7 wherein the one or more environmental parameters is a temperature and humidity index (THI) calculated from the monitored temperature and humidity.

10. The system according to any one of the preceding claims wherein the control unit is configured to automatically determine the daytime period and the night-time period based on a daily variation of the sensed one or more environmental parameters collected over a period of one or more days.

11. The system according to any one of the preceding claims wherein the control unit is configured to receive input from a user to determine the daytime period and the nighttime period.

12. A control unit (108) for a system according to any one of the preceding claims, wherein the control unit is configured to:• receive input from the sensor system regarding the one or more environmental parameters during a night-time period and determine if the input fulfils a night-time cooling criterion;• select a daytime cooling mode for a subsequent daytime period based on fulfilment of the night-time cooling criterion; and• control the one or more cooling devices during the daytime period according to the selected daytime cooling mode.

13. A computer implemented method (300) for cooling dairy animals in a barn using one or more cooling devices for blowing air and / or spraying water, the method comprising: monitoring (301) one or more environmental parameters in the barn, including temperature; receiving input regarding the one or more environmental parameters during a nighttime period and determining (303) if the input fulfils a night-time cooling criterion; selecting a daytime cooling mode (304, 305) for a subsequent daytime period based on fulfilment of the night-time cooling criterion; and controlling (306, 307) one or more cooling devices during the daytime period according to the selected daytime cooling mode.

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