JPS59162823A - Temperature and humidity controller in greenhouse - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the control of temperature and humidity within a greenhouse by recovering and regenerating thermal energy/l'yah and water.

The present invention is particularly intended for use in large, automatically controlled temperature systems in which flowers, vegetables and other plants are commercially grown, but may be used with other sealable structures. , plants are grown within this structure, such as a miniature greenhouse, plant room, plastic tunnel, etc., where thermal energy (e.g. for home heating), distilled water, or both can be obtained. Greenhouses used on a commercial scale are Usually heating and ventilation, in case 4, requires the installation of shading or heat removal equipment that can maintain the temperature within the greenhouse within specified limits appropriate for the plants in the greenhouse. . In favorable climates or weather, the cost of providing additional heat to a greenhouse is small, and by judiciously choosing the times to heat and seal the greenhouse, it is not difficult to maintain adequate conditions within it. It doesn't particularly cost anything. However, when climate and weather conditions change or are unpredictable, the use of greenhouses becomes commercially unviable, and often the equipment required to supply heat to the greenhouse from an external source in the most unfavorable weather conditions is The high capital costs of such equipment or the cost of operating such equipment during extended periods of inclement weather make it unprofitable.

Plants generally do not use solar energy efficiently for photosynthesis, but it can be said that they generally use it efficiently for transpiration, that is, for water vapor generation. This can therefore be achieved by heat pumps, which extract water vapor from the air inside the greenhouse, obtain heat from condensation, are conveniently called refrigeration and dehumidifiers, and which keep the internal temperature of the greenhouse within specified limits. provide some or all of the heating normally required to maintain This condensation and extraction of water vapor also helps maintain the relative humidity of the greenhouse air within specified ranges essential for healthy plant growth. Theoretically, it is proposed to obtain such heat pumps (hereinafter referred to simply as heat pumps) for these purposes, but to date no devices have been created that are suitable for operation on a commercial scale.

Control of this heat pump and other operations that seal and ventilate the greenhouse may be affected by evaporative cooling by refrigeration or by spraying, misting, misting, and movable shading if over-reliance is required on supplementary heating or artificial cooling with equipment. If it can be avoided,
Must depend, at least in part, on prevailing weather conditions. However, if temperature and relative humidity are considered as the only variables, it can be assumed that there are many different weather conditions for which the configuration of the control system is not feasible.

One of the features of the invention is the assumption that the conditions within the greenhouse are always assumed to fall within one of a relatively small number of different conditions. In practice, the specific conditions are determined by whether the temperature and relative humidity within the greenhouse are each within specified limits. In the actual system described below, this selection of criteria can be used to establish nine different predetermined conditions that actually exist within the greenhouse.

A next feature of the invention is that weather conditions, expressed as ambient temperature and ambient relative humidity, can be analyzed to determine that the relatively small number of possible weather conditions that actually exist are out of order. It is a temporary hole.

In the example described later, which requires the measurement of one other parameter, the general weather conditions are considered different from the 32 possible predetermined conditions, since the wind speed is considered separately. It can be decided as one.

Reducing the myriad of potential conditions inside the greenhouse and reducing the weather conditions outside the greenhouse to a relatively small set of predetermined conditions means that a given condition in temperature and a given weather condition outside the greenhouse and enables the setting of control logic that can be easily programmed to select the appropriate mode of operation for the heat pump and its equipment and maintain the desired conditions within the greenhouse.

For a given climatic and greenhouse condition, there may be more than one suitable mode of operation, and also because of the practical differences between the parameters of greenhouse conditions and the appropriate specified limits for this parameter. It is understood that there is a measurement.

It is therefore necessary or desirable for a given pair of conditions, i.e. greenhouse interior conditions and ambient weather conditions, that a transition occur between different modes of operation, for example when said parameters approach or leave their respective limits. The operation of the device is nevertheless essentially the same.

The invention will now be particularly described with reference to the accompanying drawings.

The device shown in FIG. 1 is given by way of example, and the division of the device into illustrated sections is primarily for convenience of description. A greenhouse 1 is shown with a ventilation and sealing device 2 within the device. The greenhouse has a sensor 3 adapted to sense the humidity and relative humidity inside the greenhouse.

Associated with the greenhouse is a heat exchange device 4 which, for reasons explained later, is shown partly inside the greenhouse and partly outside the greenhouse. There is optionally but preferably a heat source 5, which for example consists of a water tank normally operating between 5°C and 50°C. Preferably, the amount of water in the tank is varied by changing the depth of the water in the tank, in order to meet the anticipated heat requirements at a given time, operating between the above temperatures. In other words, in summer, when droughts continue, there is less water stored. The heat source tank is insulated by the surrounding soil and has an insulating lid.

The sensor 3, in conjunction with the logic, provides a signal indicating whether the temperature and humidity within the greenhouse are within specified ranges, respectively, as described above. These signals are used within the control p-thick, which is configured as described below. The whole device has a sensor 8, which has a device for measuring the ambient temperature and the ambient relative humidity, and preferably a device for measuring the presence or absence of sunlight. These sensors work with Logic 9 to
providing a signal indicating a particular weather condition to the control logic 7;
^-・419, The control logic controls the ventilation, sealing device 2 and heat exchange device 4. The wind speed sensor 15 may optionally override or modify the controls operating the ventilation and sealing devices, for example in high winds.

In effect, the logic 6.7.9 merges and constitutes different, but in practice inseparable parts of the data processor.

One possibility for configuring the control of heat pump equipment and greenhouse ventilation is to provide multiple control links between the various sensors and the equipment to be controlled. for example,
The greenhouse temperature is checked every two minutes and an entry is made in the register if it is outside the set range. If a scan of the register has 5 or more entries, which indicates that the greenhouse temperature is not only intergrouply away from the set range, then determine whether the temperature is too high. Another enquiry is generated within the instructions to close the greenhouse ventilator if it is determined to be open. However, if the ventilation system is closed, the heat pump's controller will be able to determine various other enquiries, such as whether the relative humidity is above or below the economic minimum, whether the heat pump is in latent mode, etc.
Depends on whether it is in sensible heating mode, whether sponsored heating equipment is working, whether the heat source is above or below the minimum economic temperature, whether the time is within 7 hours or some other specific time of daylight, etc. It can be arranged like this. On the other hand, if
If the temperature is too high, further enquiries will cause the heat pump to be reversed, the ventilator to be opened, or other operations as desired.

However, such attempts tend to be piecemeal, and a more convenient approach to the problem is to analyze the conditions in the greenhouse into one of a predetermined number; There is an analysis of the weather conditions to determine, and there is also an automatic selection of the mode of operation of the device for each possible combination of weather conditions and greenhouse conditions.

The conditions inside the greenhouse are actually determined by a logic tree.
Preferably, this tree automatically analyzes (1) whether the greenhouse temperature is within a set range, and (only if not) whether the temperature is too high or too low; (2) Determine whether the relative humidity is below the set maximum; (3) Determine whether the relative humidity is below the set minimum. This enquiry tree provides one of nine logic stages: temperature is too high, too low, or within a set range, and relative humidity is too high, too low, or within a set range. To perform the relevant enquiries, the appliances within the greenhouse measure the internal temperature and relative humidity and compare these values to a desired range, for example every two minutes. Humidity sensed by a thermocouple or the like may have a set range of, for example, 20°C to 21°C. A common temperature sensor is used to measure relative humidity.

The device just mentioned above does not indicate the magnitude and rate of change of the difference between a particular value of temperature or relative humidity and the associated set range. However, by placing an indication of the actual measurement value in a register for each scan, the rate of change and the meaning of the change can be easily determined and proportional control can be obtained if desired.

However, for simplicity's sake, there is no proportional control, and the control logic, for example every 2 minutes, measures the internal conditions of the greenhouse, puts a signal indicating this in memory, and determines the final weather conditions (as discussed later). and select operating modes of various equipment according to predetermined harmony between weather conditions and internal conditions, bring temperature and relative humidity within set ranges,
Assume that the condition of this equipment and the general conditions within the greenhouse are to be measured sequentially, for example, every 2 minutes for up to 10 minutes. If the temperature and humidity deviation from the set range still persists during this time period, an alarm will sound so that the operator can take necessary override actions. For example, is the specific treatment or form required for the general conditions inside and outside the greenhouse, such as opening ventilation systems or heating? Assume that you want to operate the pump in a particular manner, requiring the inflatable panels for the greenhouse to deflate.

Signals indicating that these devices are operating as desired are placed in registers, and when the entries in the register are multiples of, say, 5, even though the equipment is clearly functioning correctly. Indicating that the temperature or humidity error still persists, the alarm will sound and the entry in the register will disappear.

Various plans are adopted to analyze weather conditions.

The following analysis is given as an example.

In this analysis, weather conditions are assumed to be one of the 32 items. These items are defined as follows, and the definition is according to each pair of items, the items in a pair differing from each other only by the presence or absence of sunlight, and these are according to the article, which roughly indicates what controls should be there.

Items 1 and 20 Ambient temperature is above a predetermined maximum, relative humidity is below a predetermined maximum, and ambient relative humidity is below internal relative humidity. These conditions include hot dry weather and require cooling and sealing of the greenhouse.

Items 6 and 40 The ambient temperature is above the set maximum, the ambient relative humidity is below said maximum, and the ambient relative humidity is above the internal relative humidity. These conditions include hot dry but wetter weather than inside the greenhouse and ambient conditions provide a good source of heat for the heat source.

Items 5 and 61 Ambient temperature is above the set maximum, ambient relative humidity is above the set maximum, and ambient relative humidity is below the internal relative humidity. The weather is hot and humid, but drier than inside the greenhouse.

Items 7 and 8. The temperature is above the set maximum, the ambient relative humidity is above the set maximum, and the ambient relative humidity is above the internal relative humidity. The weather is hot and extremely humid.

Items 9 and 109 The ambient temperature is within the set range, the ambient relative humidity is below the set maximum, and the ambient relative humidity is below the internal relative humidity. The weather is warm and dry, and air obtained from the atmosphere can be used directly to reduce internal relative humidity.

Items 11 and 120 The ambient temperature is within the set range, and the ambient relative humidity is below the set maximum and above the internal relative humidity. The ambient air is warm and dry enough for use, but more humid than inside the greenhouse. It is a good heat source.

Items 13 and 149 The ambient temperature is within the set range, the ambient relative humidity is above the set maximum, and the ambient relative humidity is below the internal relative humidity. The atmosphere is moist enough to be warm, but drier than the interior.

Items 15 and 160 Ambient temperature is within the set range, ambient relative humidity is above the set maximum and above the internal relative humidity. The atmosphere is moist enough to be warm and humid than the interior;
It is a good heat source.

At this stage, it is appropriate to mention that weather conditions that fall within the first eight categories require cooling inside the greenhouse, but items 1, 3, and 5°7 indicate that there is a gain in sunlight. be.

If the weather falls into any of items 9 to 16, the temperature inside the greenhouse can be brought to the set temperature by ventilation. Items 9, 11, 1 as expected from the above
3.15 shows the coupling of solar gain.

Items 17 and 180 Ambient temperature is below the set range but above the internal temperature; ambient relative humidity is below the set maximum and below the internal relative humidity. The weather is either cold or warmer and drier than inside the greenhouse.

Items 19 and 20. The temperature is below the set range but above the greenhouse interior temperature, and the ambient relative humidity is below the set maximum but above the interior relative humidity. The atmosphere is cold but warmer than the inside of the greenhouse, and dry enough to use but wetter than the inside.

Items 21 and 221 Ambient temperature is below the set range but above the internal temperature, and ambient relative humidity is above the set maximum but below the internal relative humidity. The atmosphere is moist enough to use, but drier than the interior.

Items 26 and 240 Ambient temperature is below the set range but above the internal temperature; ambient relative humidity is above the set maximum and above the internal relative humidity. The atmosphere is cool and humid enough to be used, and is moister than the interior, providing a source of latent heat.

If the weather conditions fall within items 17 to 24, the temperature inside the greenhouse will be lower than the set temperature. Item 17゜19.21.2
3 indicates the solar gain. Moreover, the ambient temperature is warmer than the inside, but the inside of the greenhouse is too cold.

Items '25 and 26. The temperature is below the set range, and below the internal temperature, and the ambient relative humidity is below the set maximum and below the internal relative humidity. The atmosphere is cold and dry and can only be used to reduce internal relative humidity.

Items 27 and 288 Ambient temperature is below the set range and below the internal temperature, and ambient relative humidity is below the set maximum but above the internal relative humidity. The atmosphere is cool, drier than the maximum but wetter than the interior.

Items 29 and 601: Ambient temperature is below the set range, but below the internal temperature; Ambient relative humidity is above the repeated value, but below the internal relative humidity. The atmosphere is cold and humid, but drier than the interior.

Items 61 and 32. The temperature is below the set range but above the internal temperature, and the ambient relative humidity is above the set maximum and above the internal relative humidity. The weather is cold and damp.

It is noted that which weather conditions exist can be determined by matching the atmospheric temperature and relative humidity with respect to a particular set of ranges and, respectively, with respect to the temperature and relative humidity inside the greenhouse. The specific weather conditions present can therefore be easily identified by one of 62 different encoded signals. When this signal is created, the conditions inside and outside the greenhouse are measured for control purposes. In order to measure how control is provided, it is necessary to consider which mode of operation is performed by the operation of the greenhouse structure and by the operation of the heat pump.

In this example, there are 17 different control styles for the heat pump or heat exchanger. To understand these styles, reference is made to FIG. 2, where numeral 10 indicates the inside of the greenhouse and numeral 1
1 indicates a first heat exchanger consisting of a fan and a coil condenser, 12 indicates a second heat exchanger consisting of a fan and a coil evaporator, and 13 indicates a second heat exchanger consisting of a fan, a coil condenser, and an evaporator. An external heat exchanger is added, numeral 14 designating a shell and tube heat exchanger which acts as a condenser or evaporator. It is noted that the dual function that could be considered available for the heat exchangers 13, 14 is not possible due to the constraints imposed by the refrigeration circuit. In this case, the dual function of these two heat exchangers must be performed in each case with a separate condenser and evaporator.

A heat pump composed of heat exchangers should have the following 17 types of operation modes, the first 16 of which are in groups for 2 types, and the operation of the heat exchanger is the same as in each of the 2 groups. However, the airflow differs between the modalities within each of the two groups.

In the first mode or mode 1, the heat exchanger 11.12 is activated;
Requires heat exchangers 13,14 to be inactive.

In form 1(a), air passes through the heat exchanger 11 from the inside,
It then flows through the heat exchanger 12 and back into the greenhouse. Therefore, the latent heat emitted from inside the greenhouse is converted into sensible heat. Form 1
In (b), the internal air flows to the outside through the heat exchanger 11, and the external air flows to the inside through the heat exchanger 12. So latent heat is converted to sensible heat.

In mode θ, heat exchangers 11 and 14 operate, the latter in its condenser mode. In mode 2(a), the internal air flows through the heat exchanger 11 so that the internal latent heat is available and pumped into the heat exchanger 14 and thus into the heat source. In mode 2(b), internal air flows to the outside via heat exchanger 11, and external air flows to the interior via heat exchanger 12 (inactive). Internal latent heat is pumped into the heat source via heat exchangers 11.14.

In mode (3), heat exchangers 11,12 operate and heat exchanger 14 operates in its condenser mode.

In mode 6(a), air flows from the interior back to the interior via the heat exchanger 11, 12, and the latent heat released from the interior air is converted to sensible heat for the return air and is transferred to the heat source via the heat exchanger 14. It can be pumped. In mode 3(b), internal air exits via heat exchanger 11 and external air enters via heat exchanger 12. The internal latent heat is then converted to sensible heat and pumped into the heat source.

In mode (4), heat exchanger 12 is activated and heat exchanger 14
operates in one manner with its elevator. In mode 4(a) the air flows from inside the greenhouse through the heat exchanger 12 and back again, whereas in mode 4(b) the internal air flows out via the inactive heat exchanger 11 and the external air flows through the inactive heat exchanger 11. It flows through the heat exchanger 12. In both types, heat from the heat source is pumped inside the greenhouse.

In mode (5), the heat exchangers 11.12 are activated and the heat exchanger [
1J14 is in one style of its evaporator. Form 5 (a
), the internal air flows back into the greenhouse interior via heat exchangers 11, 12, whereas in mode 5(b), the internal air flows to the outside via heat exchanger 11, and the external air flows through heat exchangers 12 and 12.
It flows into the greenhouse through In both modes, latent heat is converted to sensible heat, which is added to the air entering or re-entering the greenhouse and supplemented by heat from the heat source.

In mode (6), heat exchanger 11.12 is activated and heat exchanger 13.14 is deactivated. In mode 6(a), external air flows back to the outside via heat exchanger 11, while internal air flows back to the inside via heat exchanger 12. In mode 6(b), ambient air flows back to the exterior through heat exchanger 12, while outside air also flows to the interior through heat exchanger 12.

In mode (7) only heat exchangers 11.12.13 are activated. Format 7 (→, the air is transferred from the inside to the heat exchanger 11.1
In mode 7(b), air flows out from the interior via heat exchanger 11 and external air flows in via heat exchanger 12.

In mode (8), heat exchangers 11 and 12 are activated, and in mode 8 (
In case 28(b), the internal air flows back to the inside through the heat exchanger 11, while the outside air flows back to the outside through the heat exchanger 12. It flows into the atmosphere through .12.

Finally, in form (9), heat exchangers 11 and 12 are activated,
Atmospheric air flows through the heat exchanger 11 and then through the heat exchanger 12 into the greenhouse. In this way the air from the atmosphere is dried, reheated and entered into the greenhouse.

Apart from the substantial variety of modes of operation of heat pumps, other modes of operation are provided, which can be said to deal with the construction of greenhouses, and, moreover, membrane means techniques such as heating with assisted heating devices, cooling with sprinklers, etc. There is a mode of operation that can be said to be.

The final step in configuring the control device requires harmonization of internal and external conditions. The following statement may serve as an example.

Assuming interior condition 1, the interior is too cold and too wet. If weather conditions 1', 2.9 or 10 exist, assuming that the wind speed does not interfere with the ventilation of the greenhouse, the correct measures are to ventilate the greenhouse, run the ventilation fan at full speed, and if the panels are inflated, within the set range. The purpose is to shrink the panel until it reaches .

The greenhouse must then be sealed and the panels inflated to prevent overheating and possible over-drying. Second
An example is when there is an internal condition 1 and a weather condition 31. The greenhouse exhaust is then closed and the heat pump must be operated in mode 1. Form 1(a) and Form 1(
The choice between b) depends on the relative temperature of the ambient air and the air coming from the evaporator coil. If the conditions are not brought within the set range, the control logic must operate the sponsored heating system to inflate the panel if necessary. If these measures are not implemented, an alarm will sound.

The third example is a case where there is an internal condition 1 and a weather condition 32. In this case, the panels have already expanded and if the heat pump is operating in Mode 1(a) or Mode 1(b), the internal relative humidity will decrease below the set maximum and therefore the control logic will The mode of operation must be changed to mode 5 or mode 7 and then to mode 4 or mode 6.

Finally, it is convenient to summarize the heat sources for heat pumps and the uses of the rejected heat. The heat sources include (a) internal air via exchanger 11, (b) stored heat via exchanger 14, and (C) atmospheric air via exchanger 13. Heat source (a) is format 1, 2
．． 3.5, 6, 7.8, and the heat source (b) is Form 4
, 5, and the heat source (C) is used in Form 6.7. Mode 9 also obtains its heat source from the atmosphere via exchanger 11. heat source (
c) (b) can be combined and proportioned by water flow to the heat exchanger 14 via a mode 5 thermostatically controlled valve. Moreover, the heat source (a) (C
) can be proportionalized by appropriate operation of the heat exchanger fan or by a Type 7 air restrictor flap valve. Form 1
should normally follow Form 6 and Form 2, Form 2 changes to Form 1 via Form 6, Form 4 changes to Form 5, Form 5 changes to Form 4, Form 6 changes to Form 7, etc. , and it is noted that it changes to the opposite.

[Brief explanation of the drawing]

FIG. 1 is an illustration of a greenhouse and its control equipment; FIG. 2 is an illustration of a heat exchanger forming part of the apparatus shown in FIG. 1; DESCRIPTION OF SYMBOLS 1... Greenhouse, 2... Ventilation, sealing device, 3... Sensor, 4... Heat exchanger, 5... Heat source, 6... Logic, 7... Control logic, 8...・・Sensor, 9・・
・Logic, 10... Inside the greenhouse, 11, 12, 13.
14... Heat exchanger, 15... Anemometer. Attorney: Akira Asamura Procedural Amendment 1980 G/G'' Date: Mr. Commissioner of the Japan Patent Office 1, Indication of Case 1982 Patent Application No. 56892 Bow 2, Name of Invention Temperature and Humidity Control Device in Greenhouse 3, Amendment Relationship with the case of the person who made the amendment Patent applicant 4, agent 5, amendment order 6 Nikkan Showa 1999, Month, Day 8, Contents of the amendment: The engraving of the specification as shown in the attached sheet (no changes to the content)

Claims (1)

[Claims] By optimizing the recovery, regeneration and use of heat and water,
A device for controlling temperature and humidity in a greenhouse, comprising: a device for sealing and evacuating the greenhouse; an inside or outside of the greenhouse;
or a heat pump having a device capable of generating thermal energy and distilled water from water vapor in the air and sending the thermal energy into the air from the inside or outside of the greenhouse to the inside or outside of the greenhouse. a device for controlling the air flow of the heat pump by the heat pump; a device for issuing a control signal indicating whether the temperature and humidity are within respective specified ranges; a device for obtaining an indication of the presence of an object outside a set of weather conditions; and control logic, the control logic controlling a plurality of predetermined modes of operation of the device in response to the indicated weather conditions. A temperature and humidity control device in a greenhouse which maintains or serves to maintain the temperature and humidity in the greenhouse within S limits by selecting a specific mode outside of the range.