JPS6251315B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides at least NaCH ₃ COO,
This invention relates to a heat storage material made of NH ₂ CH ₂ COOH and H ₂ O. In general, there are two types of heat storage materials known: those that utilize the sensible heat of substances and those that utilize latent heat. Heat storage materials that use latent heat have a larger amount of heat storage per unit weight and unit volume than heat storage materials that use sensible heat, and require only a small amount of heat storage material to store the required amount of heat. Therefore, the heat storage device can be downsized. A heat storage material that uses latent heat has a characteristic that unlike a heat storage material that uses sensible heat, the temperature does not drop with heat radiation, and instead radiates heat at a constant temperature at a transition point. In particular, heat storage materials that utilize the latent heat of fusion of inorganic hydrates are known to have a large amount of heat storage per unit volume. By the way, NaCH ₃ COO・3H ₂ O (melting point
58.2℃) is the latent heat of fusion among inorganic hydrates.
It is known to be a particularly large substance at 63 cal/g. However, NaCH ₃ COO・3H ₂ O has a melting point of
Because of its high temperature of 58.2 degrees Celsius, it has been difficult to widely apply it to heat storage devices that utilize solar heat. Therefore, methods have been proposed to lower the melting point by adding various acetates and other inorganic salts to NaCH ₃ COO 3H ₂ O, but these methods reduce the latent heat of fusion more than necessary as the melting point decreases. However, it was difficult to put it into practical use. The present invention provides at least NaCH ₃ COO,
By changing the composition of a system consisting of NH ₂ CH ₂ COOH and H ₂ O, heat storage temperature and heat radiation temperature can be controlled, and a heat storage material that is inexpensive, has stable heat absorption and radiation performance, and has a large amount of heat storage is provided. The purpose is to The heat storage material of the present invention is characterized by at least
It is composed of three components: NaCH ₃ COO, NH ₂ CH ₂ COOH and H ₂ O. More preferably, the composition ratio of these three is in the range of 45.0 to 62.5% by weight for NaCH ₃ COO,
The heat storage material has a content of NH ₂ CH ₂ COOH in a range of 1.25 to 25.0% by weight, and a content of H ₂ O in a range of 30 to 42.5% by weight. Even more desirable is
A heat storage material that has a composition of NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH as both end components, and contains NH ₂ CH ₂ COOH in an amount of 30% by weight or less (excluding 0%). be. The present invention will be described below with reference to Examples. Commercially available reagent grade NaCH ₃ COO, NaCH ₃ COO・
Using 3H ₂ O, NH ₂ CH ₂ COOH and H ₂ O purified by distillation and ion exchange, predetermined amounts were blended as shown in Tables 1 and 2, and the mixture was heated to 65°C. The solids were dissolved as much as possible and used as a sample. The magnitude of latent heat and transition temperature of these samples were measured using a differential scanning calorimeter (DSC). The measurement results are shown in Tables 3 and 4. By the way, Table 1 shows
The sample whose end components are NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH is shown in Table 2.
This is a peripheral composition with NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH as both end components. In Tables 3 and 4, the peak temperature of the DSC curve is shown as the transition temperature, and for samples that undergo transition at two temperatures, those temperatures are shown, respectively. The latent heat is the sum of those due to these transitions. By the way, as a matter of course, the transition below 0° C. was considered unnecessary in this case, so it was targeted. The evaluations in Tables 3 and 4 show that the latent heat is 30cal/
Samples with a weight of 20g or more are marked with a circle, and the latent heat is 20cal/g.
△ for samples with more than 30 cal/g, otherwise ×
And so. By the way, as a matter of course, the samples marked with ○ have a large amount of heat storage and can be put to practical use, and the samples marked with △ have a not so large amount of heat storage, but their transition temperature is higher than that of conventional latent heat storage. Since the temperature range is not found in other materials, it is thought that it can be put to practical use.

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[Table] Analyzing the data in Table 3, NaCH ₃ COO・
3 of NaCH _{3 COO} , NH ₂ CH ₂ COOH, and H 2 O, which has a composition of _3H 2 O and NH ₂ CH ₂ COOH as both end _components .
In the component system, in sample 1 containing 0.2% by weight of NH ₂ CH ₂ COOH, the transition point decreases to 57.9°C, but the latent heat is 63 cal/g, and NaCH ₃ COO・
Almost equal to that of 3H ₂ O. So,
As the content of NH ₂ CH ₂ COOH increases, the transition point gradually decreases, and the latent heat also decreases, albeit slightly. In samples containing NH ₂ CH ₂ COOH of 2% by weight or more, a transition different from the conventional transition is observed around 45°C.
As the content of NH ₂ CH ₂ COOH increases, the transition point on the high temperature side decreases, and the transition point on the low temperature side almost maintains that temperature. In samples containing 15% by weight or more of NH ₂ CH ₂ COOH, the transition on the low temperature side is observed to almost overlap with the transition on the high temperature side. So, sample 8,
9,10, 15-30% by weight of NH ₂ CH ₂ COOH
Contains NaCH ₃ COO・3H ₂ O and
The composition containing NH ₂ CH ₂ COOH as both end components is heated to 45°C.
It can be seen that it has a transition point nearby and has a latent heat of over 40 cal/g, making it an excellent heat storage material.
For samples containing more NH ₂ CH ₂ COOH, the transition point decreases slightly, but the latent heat decreases significantly. After all, it has NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH as both end components, and contains NH ₂ CH ₂ COOH in a range of 30% by weight or less (excluding 0%).
The three-component composition of NaCH ₃ COO, NH ₂ CH ₂ COOH, and H ₂ O can control the heat storage temperature and heat radiation temperature by changing their composition, and has a latent heat of 40 cal/g or more. This makes it an extremely excellent heat storage material that has never existed before. Next, with NaCH ₃ COO・3H ₂ O shown in Table 4,
Analyze the characteristics of samples in the region around the composition with NH ₂ CH ₂ COOH as both end components. Sample 13 to sample 20
The content of NH ₂ CH ₂ COOH was kept constant at 5% by weight, and the contents of NaCH ₃ COO and H ₂ O were varied. By the way, samples 13 to 16 are
NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH are the H ₂ O-excess side of the composition, that is, NaCH ₃ COO
Samples 17 to 20 have compositions on the deficient side, and conversely, NaCH ₃ COO 3H ₂ O.
This sample has a composition with NH ₂ CH ₂ COOH as both end components, on the H ₂ O deficient side, that is, on the NaCH ₃ COO excess side. Therefore, from sample 13 on the H ₂ O excess side,
Without changing the content of NH ₂ CH ₂ COOH,
As the content of NaCH ₃ COO increases, that is, as it changes from sample 14 to sample 15 to sample 16,
The latent heat increases and the transition temperature also increases. And NaCH ₃ COO 3H ₂ O and NH ₂ CH ₂ COOH
has a composition with both end components, and
Sample 4 shown in Table 3 containing 5% by weight of NH ₂ CH ₂ COOH has the maximum latent heat, and
Even with increasing the content of NaCH ₃ COO, sample 17,
As can be seen from the characteristics of Samples 18, 19, and 20, the latent heat does not increase, but rather decreases. The transition temperature increases as the content of NaCH ₃ COO increases, without having a maximum in the middle. Such a relationship was also observed among samples containing 25% by weight of NH ₂ CH ₂ COOH, and between NaCH ₃ COO and 3H ₂ O.
Sample 27, which has a composition with both ends of NH ₂ CH ₂ COOH, has the largest latent heat, and the transition point is
It can be seen that the value increases as the content of NaCH ₃ COO increases. That is, NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH
Compared to a composition with , as both end components, the transition point is lower on the H ₂ O excess side, that is, the NaCH ₃ COO-deficient side, and conversely, the transition point is slightly lower on the H ₂ O-deficient side, that is, on the NaCH ₃ COO-excess side. Rise. And the latent heat is
From the composition with NaCH ₃ COO・3H ₂ O and NH ₂ CH ₂ COOH as both end components, the H ₂ O excess side and the H ₂ O deficiency side, i.e.
It decreases whether it shifts to the NaCH ₃ COO-deficient side or the NaCH ₃ COO-excess side. To summarize the above results, among the compositional regions of the samples marked with △ and ○ in the evaluations of Tables 3 and 4, the region where the latent heat does not decrease much even though the melting point has decreased significantly, that is, NaCH ₃ COO,
In the three-component system of NH ₂ CH ₂ COOH, H ₂ O,
_NaCH3COO ranges from 45 to 62.5% by weight;
Preferably, _NH2CH2COOH is in the range of 1.25% to 25% by weight and _H2O is in the range of 30 to _42.5 % by weight. Next, 48.2% by weight of NaCH ₃ COO,
800 g of a mixture with the same composition as Sample 9, which was a mixture of 20% by weight of NH ₂ CH ₂ COOH and 31.8% by weight of H ₂ O.
20g of Na ₄ P ₂ O ₇・10H ₂ O as a supercooling prevention material.
In addition, it was placed in a cylindrical container with an inner diameter of 100 mm and a height of 100 mm, and sealed with a stopper equipped with a thermocouple insertion tube. that container
When repeatedly heated and cooled between 35°C and 55°C, there was almost no supercooling, and the heat storage material of the present invention repeatedly melted and solidified stably, and there were no problems with the heat storage material of the present invention even during continuous use. It was confirmed that it had stable heat absorption and radiation performance. As mentioned above, the present invention provides at least
It consists of three components: NaCH ₃ COO, NH ₂ CH ₂ COO, and H ₂ O. By changing their composition, the heat storage temperature and heat radiation temperature can be controlled. It is inexpensive and has stable heat absorption and radiation performance. A large heat storage material can be provided. In addition, in the present invention, CO
(NH ₂ ) ₂ or other melting point depressants,
Even if a supercooling prevention agent such as Na ₂ H ₂ P ₄ O ₇ is added, a thickener is added to prevent the supercooling prevention agent from settling or agglomeration, or other additives are added as appropriate. Of course it's good. As is clear from the above description, the heat storage material of the present invention can be applied not only to air conditioning heat storage devices for cooling and heating purposes, but also to all fields that utilize heat storage.

Claims (1)

[Claims] 1 Containing at least NaCH ₃ COO, H ₂ NCH ₂ COOH and H ₂ O as constituent components, NaCH ₃ COO is in the range of 45% to 60% by weight, and H ₂ NCH ₂ COOH is 2% by weight.
Ranges from wt% to 25wt% with _H2O at 30wt%
A heat storage material characterized by being in the range of ~40% by weight.