JPS6247720A - Preventing system for dew condensation - Google Patents

Abstract

PURPOSE:To prevent effectively the damage due to the dew condensation and to reduce the operating cost by switching automatically the set value between the daytime and the night for the difference of surplus temperature for prevention of dew condensation. CONSTITUTION:A dew condensation preventing system consists of an open air sensor 1 which detects the temperature and the humidity of the open air, a temperature sensor 2 attached onto the floor, etc. of a warehouse and a detector 10 for prevention of dew condensation. The detector 10 is provided with an arithmetic circuit 11 consisting of a microcomputer, etc., a setter 12 which sets the difference of surplus temperature for prevention of dew condensation, a comparator 13, a remote controller 18, etc. Then the detection signal of the sensor 1 is supplied to the circuit 11 and the dew point temperature is obtained from an air line chart stored in a ROM. At the same time, the comparator 13 obtains the difference between said dew point temperature and the floor surface temperature obtained by the sensor 2. Furthermore this obtained difference is compared with the difference of surplus temperature for prevention of dew condensation. Then the controller 18 is actuated for output of an alarm for dew condensation and a dehumidifying command. Thus a dehumidifier is operated. At the same time, said difference of the surplus temperature is switched between the daytime and the night for reduction of the operating cost of this system.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dew condensation prevention method for preventing dew condensation on stored items in a warehouse or the like.

[Conventional technology]

One possible way to prevent condensation from occurring in warehouses is to keep the warehouse air-conditioned at all times, but it is difficult to predict when condensation will occur, so constantly air-conditioning requires enormous running costs. becomes. Therefore, a temperature and humidity sensor is used to detect the possibility of condensation, and the dehumidifier is operated only when there is a risk of condensation, thereby reducing operating costs. In this case, the dehumidifier is operated by manually setting a condensation prevention margin temperature difference in the dew condensation prevention detector, and when this set value is reached, the dehumidifier is started to operate. In addition, to prevent condensation, a ceiling fan installed on the ceiling of the warehouse blows warm air stagnant near the ceiling onto the floor surface, raising the floor temperature and stirring the air inside the warehouse. This prevented condensation from occurring.

[Problem that the invention seeks to solve]

Conventional condensation prevention systems are configured as described above, and the condensation prevention margin temperature difference is manually set, and the same temperature difference is set during the day and night, so condensation can be prevented even under nighttime conditions, when the conditions for condensation are severe. The prevention margin temperature difference had to be set large, and it was not possible to obtain sufficient effects in reliably preventing dew condensation and reducing operating costs. Furthermore, ceiling fans used to prevent condensation were selected based on their ability to agitate indoor air, with no particular consideration given to their effectiveness in preventing condensation.

This invention was made to solve the above-mentioned problems, and aims to significantly reduce operating costs of dehumidification equipment while effectively preventing damage from condensation. .

[Failure to solve the problem]

The condensation prevention system according to the present invention includes a sensor that detects the temperature and humidity of the outside air, a sensor that detects the floor temperature, an arithmetic circuit that determines the dew point, and a condensation prevention margin temperature that automatically switches the set value between daytime and nighttime. The dehumidifier is equipped with a difference setting device, and the operation of the dehumidifier is turned ON and OFF according to each set value.

[Effect]

The condensation prevention system according to the present invention detects the temperature and humidity using a sensor that detects the temperature and humidity of the outside air and a temperature sensor attached to the floor or luggage inside the room, and detects the danger of condensation based on the psychrometric diagram built into the arithmetic circuit. Furthermore, even before dew condensation occurs, the condensation prevention margin temperature difference can be set to, for example, 0℃ during the daytime.
At night, the temperature is automatically switched to 2°C to 4°C, and the dehumidifier is turned on and off at each setting.

[Embodiments of the invention]

FIG. 1 is a block diagram of a dew condensation prevention system showing one embodiment of the present invention. In the figure, (1) is an outside air sensor that detects the temperature and humidity of outside air, (2) is a temperature sensor that is attached to the warehouse floor or stored luggage, etc.
αQ is a non-condensation prevention detector, and has built-in ρ~(to) described below. αη is an arithmetic circuit made of a microcomputer or the like, and determines the danger of condensation based on the stored psychrometric chart. (b) is a setting device that sets the dew condensation prevention margin temperature difference, and (2) is a setting device that sets the difference between the dew point temperature determined by the calculation circuit (b) and the floor temperature measured by the temperature sensor (2), and the setting device (2).
α◆ is a comparison circuit that compares the condensation prevention margin temperature difference set in ) is an upper limit comparison circuit that compares the floor surface temperature with an upper limit value (for example, 35° C.), α・, 0 is an AND circuit, and 轡 is a remote controller that operates with the H output from η to the AND circuit.

Next, the operation of the dew condensation prevention system configured as above will be explained. The temperature and humidity signals of the outside air detected by the outside air sensor (1) are input to the arithmetic circuit α, and the dew point temperature Td is determined from the psychrometric chart stored in the ROM serving as the arithmetic circuit α. The comparison circuit (to) calculates the difference (Tr - Tdl) between the dew point temperature Td of the outside air and the floor temperature Tr detected by the temperature sensor (2), and further calculates the difference (Tr - Tdl) set by the setting device (6). It is compared with the dew condensation prevention margin temperature difference ΔT, and if ΔT)(Tr−Td), an H level signal is output. Further, the lower limit comparison circuit 04 is connected to the outside air sensor (1).
If the outside air temperature is 5° C. or higher, an H level signal is output, and if it is 5° C. or lower, an L level signal is output. Furthermore, the upper limit comparator circuit (b) outputs an L level signal to 35°C when the floor surface temperature determined by the temperature control circuit (2) is 35°C or higher.
If the temperature is below 0.degree. C., an H level signal is output. Then, these outputs are logically summed by an AND circuit (IQ, (b), and the condensation prevention margin temperature difference (Tr-'rtil) is set to the set value.
Below, when the outside air temperature is 5℃ or higher and the floor temperature is 65℃ or lower, an H level signal is output, the remote controller α barrel is operated, a condensation alarm and a dehumidification command are output, and a dehumidifier (not shown) is activated. drive.

In addition, the condensation prevention margin temperature difference set by the setting device (6) can be automatically switched between daytime and nighttime by a clock device (not shown); for example, the setting value is 0°C during the day and 6°C at night. Since the dehumidifier is operated according to the degree of risk of condensation, the operating cost of the dehumidifier can be reduced by more than 90 min while sufficiently preventing the risk of condensation.

When selecting the capacity of the dehumidifier, calculate the required amount of dehumidification by appropriately assuming the conditions for condensation to occur, such as the temperature and humidity of the outside air, the surface temperature of the cargo inside the warehouse, the volume of the warehouse, and the number of ventilations. conduct. When making assumptions about this temperature, etc., decisions are made taking into account the time of year when condensation occurs and the location conditions of the warehouse.

In addition, as a dew condensation prevention system, a ceiling fan blows warm air accumulated near the ceiling toward the floor surface, stirring the air and raising the floor surface temperature, which is extremely effective in preventing dew condensation. As an example of actual measurement, as shown in Figure 2 (a), the temperature near the floor surface decreased to approximately 6.5 liters approximately 10 minutes after the system was activated.
°C rises, and the relative humidity is about 70 °C as shown in (b)
The ceiling can be lowered to about 60 inches from the bottom, and stirring the air with a ceiling fan is also effective in preventing condensation. In this case, the capacity of the ceiling fan is to increase the wind speed reaching the floor by 0.1 to 0.2 m/
Set to a range of m. In addition, the wind speed reaching the floor surface is set to 0.1 to 0.
．． If it is less than 2 m/see, air cannot obtain a sufficient stirring effect; on the other hand, if it is 0.1 to 0.2 m/see
If the ceiling fan exceeds .see, the capacity of the ceiling fan becomes excessive, resulting in wasted power, and also causes various inconveniences such as dust being kicked up due to excessive agitation and an increase in wind speed.

〔Effect of the invention〕

As explained above, this invention automatically switches the set value of the dew condensation prevention margin temperature difference between daytime and nighttime, and according to the embodiment, the wind velocity reaching the floor surface by the ceiling fan is 0.1 to 0.2 m.
/ s1! Since the dehumidification system is configured to have a temperature of about c, it is possible to effectively prevent dew condensation damage while significantly reducing the operating cost of the dehumidification system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a dew condensation prevention system showing an embodiment of the present invention, and FIGS. 2(a) and 2(b) are diagrams showing the dehumidifying effect of a ceiling fan. In the figure, (1) is an outside air sensor, (2) is a floor temperature sensor, α0 is a dew condensation prevention detector, α force is an arithmetic circuit, (2)
is a dew condensation prevention margin temperature difference setting device, (to), α hinoki, ni) is a comparator, α・, C14 is an AND circuit, and (to) is a remote controller.

Claims (2)

[Claims] (1) In a condensation prevention system in a warehouse or the like, a temperature/humidity sensor that detects the temperature and humidity of outside air, and a temperature sensor that is attached to the indoor floor or luggage to detect the floor surface temperature,
Equipped with an arithmetic circuit that calculates the dew point temperature and a condensation prevention margin temperature difference setting device that automatically switches the set value between daytime and nighttime, it is possible to calculate the difference between the floor surface temperature and the dew point temperature and the condensation prevention margin temperature difference. The operation of the dehumidifier is turned on and off by the logical sum of the comparison value, the lower limit of the outside air temperature, and the upper limit of the floor surface temperature.
A dew condensation prevention method characterized by a method that prevents condensation. (2) Condensation prevention according to claim 1, characterized in that the dew condensation prevention margin temperature setting value is automatically switched to approximately 0°C during the day and approximately 2°C to 4°C at night. method.