JPS6281481A - Latent heat storing material - Google Patents

Abstract

PURPOSE:To provide a latent heat storing material which is free from toxicity and corrosive properties and is incombustible and melts at about 25 deg.C and which comprises Na2SO4.10H2O and MgSO4.7H2O. CONSTITUTION:1mol of Na2SO4.10H2O is blended with 0.7-1.5mol of MgSO4.7 H2O and, if necessary, a phase separation inhibitor (e.g., crosslinked acrylic acid polymer) and an undercooling inhibitor (e.g., borax), thereby adjusting the melting initiation temp. to 22.0 deg.C or above and the melting completion temp. to 28 deg.C or below and obtaining a latent heat storing material useful for temp. adjustment of hermetically sealed space in which electronic equipment is installed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a latent heat storage material used for temperature control in a closed space in which electronic equipment and the like are installed.

Conventional technologyThe temperature in a closed space where electronic equipment such as an exchanger that generates heat during operation can reach 50°C during the day due to the outside temperature exceeding 30°C and the heat radiated from the equipment. In order to ensure stable operation of electronic components, air conditioners are used to keep temperatures below 30°C. In order to achieve such air conditioning while achieving energy savings, it is effective to apply latent heat storage materials, and studies are currently underway.

Problems to be Solved by the Invention In order to adjust the temperature of the air-conditioned space to approximately 30°C, the melting point of the latent heat storage material must be approximately 25°C or lower. Naturally, the more latent heat storage materials with lower melting points are used, the lower the temperature of the air-conditioned space can be set, making it easier to achieve the above objective. It becomes difficult to prepare for heat absorption and melting the next day. If the outside temperature at night is assumed to be about 20°C, the optimal melting point will be about 25°C.

Among the many latent heat storage materials, this is one of the most practical in terms of price, nonflammability, toxicity, and corrosivity.
Sodium sulfate decahydrate (Na2804・]0H2
0). Since the melting point of this material is 32°C, it is not suitable for the above purpose and it is necessary to lower the melting point to about 25°C.

The present invention solves the above problems and solves the problems described above.
It was made for the purpose of providing a latent heat storage material with a melting point of about 25°C, which is based on T(20).

Means for Solving the Problems The latent heat storage according to the present invention can be applied to Na2SO4-10I-
20 and magnesium sulfate heptahydrate (M9804.7'F
The above object can be achieved by a configuration including at least I20).

Effects of the present invention Mg804-7 HzO is Na2SO
4.10I■20 has the effect of lowering the melting point, and Na
2 MqSO4・for SO4・1011201 mol
When 07 to 15 moles of 71120 were mixed, the melting point was about 25°C.

Example Examples of the present invention will be described below.

The figure shows Na 2 S04-101120 and Na 2
804- ] 0H20 and MgSO4・7 I-I20
The melting curve of the mixture is shown. Melting point at 32℃-)N
a 2804 @10 Mjj 80 on T-120. i
When -7I20 is mixed, the melting completion temperature decreases with the amount of M, 9SO4・71-120 mixed, as shown in the figure.
Na2SO4・10I■M for 201 mole,! 9SO
In test t1, which mixed 07 moles of 4.7I-I20, it was approximately 28
Melting is complete at °C. As shown in the figure, the melting start temperature of the above mixture is about 22°C, and a temperature difference of about 6°C occurs between the start and completion of melting, and this temperature difference is T-1a 2804
-101 (considerably higher than about 2°C in the case of zO alone. By increasing the mixing amount of M, 9SO4・7H20, Na
2SO4・10H20:MgSO4・7H20-1:1
(molar ratio), the melting completion temperature is reduced to about 25°C, and the temperature difference between melting initiation and completion is also about 3°C smaller. Although omitted in the figure, M2SO4・7H2
If the mixing amount of Na 28 is further increased, the melting completion temperature will rise again and the latent heat of fusion will gradually decrease.
04-101 (M for 201 mol, 9SO4・7■
It is not desirable to mix 15 moles or more of I20. Furthermore, if the mixing amount of Mg804.7H20 is less than 0.7 mol, the melting completion temperature will be too high at 28°C or more.
The temperature difference between the start and completion of melting becomes too large;
Practically, 07 per mole of Na2504-10H20
It is desirable to mix mol to 15 mol of MgSO4.7H205b.

In addition, since this system exhibits anharmonic melting, a cross-linked acrylic acid polymer was used as a phase separation inhibitor to prepare the sample.
:% and at the same time, 3% by weight of porcelain sand was added as an anti-supercooling agent, but other additives may be used and the presence or absence of these additives does not depart from the gist of the present invention.

Effects of the Invention As described above, the present invention provides Na2SO4・10I■20 and He4
The present invention provides a latent heat storage material containing at least 1SO4-7H20, which can set the start of melting at about 22°C or lower, and the completion of melting at about 28°C or lower. Na 2804-107+20, M
, t) SO4-7t120 are materials that can be obtained at low cost and in large quantities, and are non-toxic and non-flammable. Therefore, the latent heat storage material according to the present invention can maintain the temperature of the closed space where electronic equipment etc. are installed. Useful for regulation.

[Brief explanation of drawings]

The figure shows Na2SO4・10I-120 and Na2SO
There are 6 pages of figures showing the melting curves of mixtures of 4.10■■20 and M, 9804.10I-I20.

Claims (1)

[Claims] 1) A latent heat storage material comprising at least sodium sulfate decahydrate and magnesium sulfate heptahydrate. 2) The latent heat storage material according to claim 1, wherein 0.7 mol to 1.5 mol of magnesium sulfate heptahydrate is mixed with 1 mol of sodium sulfate decahydrate.