CN216144015U - Solar heating system using mixed salt solution as anti-freezing solution in severe cold area - Google Patents

Abstract

The utility model discloses a solar heating system in severe cold areas by taking mixed salt solution as an anti-freezing solution. The heat supply medium of the solar heat collection loop is the mixed calcium-based salt solution antifreeze solution which is added with the composite corrosion inhibitor and mainly contains calcium chloride, and the mixed calcium-based salt solution can meet different requirements of a heat supply system on the freezing point of the antifreeze solution under various working conditions to a great extent. The utility model applies the salt solution as the antifreezing heat supply medium to the solar heat supply system, solves the problems of corrosion and scaling caused by using the salt solution by adding the low-cost composite corrosion and scale inhibitor, reduces the cost of the heat supply system, and improves the performance and the safety of the system.

Description

Solar heating system using mixed salt solution as anti-freezing solution in severe cold area

Technical Field

The utility model relates to the field of solar heat supply, in particular to a solar heat supply system in a severe cold region by taking mixed salt solution as an antifreezing solution.

Background

With the steady development of the world economy, the demand of energy is increasing. The excessive development of conventional energy sources will lead to exhaustion of fossil fuels, and also aggravate emission of greenhouse gases, resulting in global warming. Under the double pressure of energy demand and climate change, people pay more and more attention to the utilization of renewable energy sources, such as wind energy, biomass energy, solar energy and the like. Solar energy is used as a clean renewable energy source, is inexhaustible, and a series of problems of energy and environment must be powerfully relieved by developing a utilization technology of the solar energy. Among them, solar heat utilization is one of the most economical and effective forms, which is a form in which solar radiation is converted into heat energy by a certain equipment and utilized. Typical solar thermal utilization is to absorb the energy of solar radiation by a solar thermal collector and use it for producing hot water for heating and other purposes.

At present, a lot of problems and difficulties which need to be solved exist in the continuous utilization of solar energy for heat supply, and the anti-freezing problem of a solar heat supply system is one of the problems existing in the utilization of solar energy in severe cold regions. Because the heat supply medium is water, the water can be frozen when the temperature is reduced to a certain degree, and the phenomenon of frost cracking of a heat supply pipeline and a radiator is easy to occur particularly in severe cold areas. In order to prevent the heat supply medium from freezing, an antifreeze is generally selected as the heat supply medium. At present, glycol antifreeze solution is widely used, but the glycol antifreeze solution has the defects of high price, certain toxicity to human bodies, increased viscosity and flow resistance under the low-temperature working condition and the like. The salt solution has the advantages of safety, no toxicity, good heat conductivity, low price and long service life, and has the defect of strong corrosivity to most metals in the presence of air. The solar heat supply system in the severe cold area with the mixed salt solution as the antifreeze takes the mixed salt solution as a heat supply medium, makes full use of the performance of various salt solutions, and adds a certain compound corrosion inhibitor, so that the corrosivity of the salt solution is greatly reduced, the solar heat supply system becomes a more economic and effective choice of the antifreeze, the operation performance of the heat supply system is improved, and the cost of the system is reduced.

SUMMERY OF THE UTILITY MODEL

The utility model aims to introduce a mixed salt solution working medium into a solar heating project, and provides a solar heating system in a severe cold region by taking the mixed salt solution as an antifreezing solution.

The utility model is realized by the following technical scheme: a solar heat supply system in severe cold areas with mixed salt solution as an antifreeze comprises a solar heat collector, a first water pump, a heat exchanger, a second water pump, a heat storage water tank and a heat supply tail end;

the solar heat collector and the heat exchanger are connected through a pipeline to form a solar heat collecting loop, the working medium of the solar heat collecting loop is a mixed salt solution, and a first water pump is installed at the inlet of the heat exchanger in the solar heat collecting loop;

the heat storage water tank and the heat exchanger are connected through a pipeline to form a water tank heat exchange loop, the working medium of the water tank heat exchange loop is water, and a second water pump is installed at the inlet of the heat exchanger in the water tank heat exchange loop;

the solar heat collection loop and the water tank heat exchange loop are coupled for heat exchange through a heat exchanger, and the heat storage water tank is connected with the heat supply tail end through a pipeline.

Further, the mixed salt solution is used as an antifreezing solution.

Further, the solar collector evacuated tube solar collector; a flow meter and a temperature detector are also arranged in the solar heat collecting loop.

Further, the heat supply end is a floor heating or fan coil.

The utility model has the beneficial effects that:

firstly, the solar heating system provided by the utility model takes the mixed salt solution as a heating medium, is safe, nontoxic, good in heat conductivity, low in price and long in service life, reduces the cost, improves the performance of the heating system and solves the problem of toxicity of the glycol compared with the currently and commonly used glycol solution.

Secondly, the solar heat supply system provided by the utility model exchanges heat with the water tank heat exchange loop through the coupling of the solar heat collection loop and the heat exchanger, so that the energy is saved, and the system structure is simpler. The heat storage water tank is arranged between the water tank heat exchange loop and the heat supply end of the user instead of direct heat exchange, on one hand, the heat storage water tank and the heat exchanger form a water path circulation, and on the other hand, the heat supply to the user is more stable. .

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

Wherein, 1, the solar energy collector; 2. a first water pump; 3. a heat exchanger; 4. a second water pump; 5. a heat storage water tank; 6. a heat supply end.

Detailed Description

The following examples are presented to enable one of ordinary skill to more fully understand the present invention and are intended to be illustrative only and should not be construed as limiting the scope of the patent; for a better illustration of the present embodiment, certain parts of the drawings have been omitted; it will be understood by those skilled in the art that certain structures in the drawings and descriptions thereof may be omitted.

As shown in fig. 1, the solar heating system using mixed salt solution as antifreeze provided by the present invention comprises a solar heat collector 1, a first water pump 2, a heat exchanger 3, a second water pump 4, a heat storage water tank 5 and a heating terminal 6;

the solar heat collector 1 and the heat exchanger 3 are connected through a pipeline to form a solar heat collecting loop, the working medium of the solar heat collecting loop is a mixed salt solution, and a first water pump 2 is installed at the inlet of the heat exchanger in the solar heat collecting loop; the solar heat collector 1 is a vacuum tube solar heat collector; the heat exchanger 3 is a plate heat exchanger;

the heat storage water tank 5 and the heat exchanger 3 are connected through a pipeline to form a water tank heat exchange loop, the working medium of the water tank heat exchange loop is water, and a second water pump 4 is installed at the inlet of the heat exchanger in the water tank heat exchange loop;

the solar heat collection loop and the water tank heat exchange loop exchange heat through the heat exchanger in a coupling mode, the heat storage water tank 5 is connected with the heat supply tail end 6 through a pipeline, energy is saved, and the system structure is simpler.

The mixed salt solution is used as an antifreezing solution, and the following formula can be selected: calcium chloride with the mass fraction of 18-25%; 5-15% of other salt (one salt such as sodium chloride and zinc chloride can be used alone or multiple salts can be used in combination, so that the total amount of the salt can meet the requirement of mass fraction); 0.3 to 0.5 mass percent of borax; 0.3-0.5% by mass of triethanolamine; the composite phosphorus-free corrosion and scale inhibitor (cationic imidazoline, acrylic acid-sulfonate copolymer, hydrolyzed polymaleic anhydride, inorganic zinc salt and benzotriazole are compounded according to the proportion of 40: 10: 10: 6: 1, and the proportion can be finely adjusted in actual use as mentioned above) with the mass fraction of 0.1-0.2%; deionized water with the mass fraction of 58.8% -76.3%. The formula can be diluted for use according to the freeze-proofing freezing point requirements of different regions. The mixed salt solution can meet the large-range demand of a heating system on the freezing point of the antifreeze according to different dilution degrees, namely the mass fractions of the components of the mixed salt solution can be changed according to the actual demand and are not unique.

Preparing raw materials of a salt solution according to a formula of a mixed salt solution, adding various raw materials into a proper container, then injecting a proper amount of deionized water and continuously stirring to prepare the mixed salt solution, wherein the mixed salt solution is required to be prepared for use. The freezing point of the antifreeze is determined according to the lowest outdoor air temperature of the region (namely, the concentration of the antifreeze is determined), a certain safety margin is ensured, the freezing point of the mixed salt solution is generally required to be 3-5 ℃ lower than the lowest outdoor air temperature, and accordingly, the mixed salt solution is diluted to meet the freezing point requirement. The method for determining the concentration of the salt solution in the specific application comprises the following steps: (1) in general use, a small amount of antifreeze solution can be prepared according to a certain salt solution concentration and placed outdoors to carry out a freezing experiment, after a certain time, if the antifreeze solution is not frozen, the concentration is proved to be proper, if the antifreeze solution is frozen, the salt solution concentration is properly increased, and the experiment is continued until the proper concentration is found; (2) laboratory control experiments can be performed on salt solutions of different concentrations when the freezing point of the salt solution is strictly required.

And filling the prepared mixed salt solution into the solar heat collecting loop. When the heating system operates, as shown in fig. 1, in the solar heat collection loop, the solar heat collector 1 absorbs light and heat to heat the mixed salt solution, the mixed salt solution acts on the pipeline through the first water pump 2 to complete circulation, and the heat is exchanged with the water tank heat exchange loop through the heat exchanger 3. In the water tank heat exchange loop, the heat supply medium is water, under the action of the second water pump 4, water flows into the heat storage water tank 5 after absorbing heat when passing through the heat exchanger 3, and then flows into the heating terminal 6 such as a floor heating device, a fan coil and the like through the heat storage water tank 5 according to the heating demand to realize heat supply.

Example (b): preparing enough calcium chloride, sodium chloride, borax, triethanolamine, cationic imidazoline, acrylic acid-sulfonate copolymer, hydrolyzed polymaleic anhydride, inorganic zinc salt and benzotriazole. The cation is first roughly described as imidazoline: acrylic acid-sulfonate copolymer: hydrolyzing polymaleic anhydride: inorganic zinc salts: the mass ratio of benzotriazole is 40: 10: 10: 6: 1, weighing a small amount of 20 mass percent of calcium chloride, 10 mass percent of sodium chloride, 0.3 mass percent of borax, 0.3 mass percent of triethanolamine and 69.3 mass percent of deionized water in another container in sequence, adding the deionized water and fully stirring to dissolve solid substances, and then adding the composite corrosion and scale inhibitor into the mixed salt solution according to 0.1 mass percent. The above experiment was performed on a small amount of the obtained mixed salt solution to see if the freezing point met the requirements. If the requirement is not met, a small amount of mixed salt solution is reconfigured, the mass fractions of calcium chloride and sodium chloride are increased, for example, the mass fraction of the calcium chloride is adjusted to be 22%, the mass fraction of the sodium chloride is adjusted to be 12%, the mass fraction of the water is reduced to be 60.3%, and the experiment is carried out again until the freezing point meets the requirement. When the freezing point meets the requirement, a large amount of mixed salt solution can be prepared according to the mass fraction of the salt solution under the condition for use in a heat supply system.

And filling the prepared mixed salt solution into the solar heat collecting loop, and filling the prepared mixed salt solution into the solar heat supply loop. When the solar heating system operates in a severe cold area, the heating medium cannot be frozen.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (4)

1. A solar heating system in severe cold areas with mixed salt solution as an anti-freezing solution is characterized by comprising a solar heat collector (1), a first water pump (2), a heat exchanger (3), a second water pump (4), a heat storage water tank (5) and a heating terminal (6);

the solar heat collector (1) and the heat exchanger (3) are connected through a pipeline to form a solar heat collecting loop, the working medium of the solar heat collecting loop is a mixed salt solution, and a first water pump (2) is installed at the inlet of the heat exchanger in the solar heat collecting loop; the solar heat collector (1) is a vacuum tube solar heat collector; the heat exchanger (3) is a plate heat exchanger;

the heat storage water tank (5) and the heat exchanger (3) are connected through a pipeline to form a water tank heat exchange loop, the working medium of the water tank heat exchange loop is water, and a second water pump (4) is installed at the inlet of the heat exchanger in the water tank heat exchange loop;

the solar heat collection loop and the water tank heat exchange loop are coupled for heat exchange through a heat exchanger, and the heat storage water tank (5) is connected with the heat supply tail end (6) through a pipeline.

2. The solar heating system for the severe cold area by taking the mixed salt solution as the anti-freezing solution as claimed in claim 1, wherein the mixed salt solution is taken as the anti-freezing solution.

3. The solar heating system for the severe cold areas by taking the mixed salt solution as the anti-freezing solution as claimed in claim 1, wherein a flow meter and a temperature detector are further installed in the solar heat collecting loop.

4. The solar heating system for the severe cold areas by taking the mixed salt solution as the anti-freezing solution as claimed in claim 1, wherein the heating end is a floor heating or fan coil.

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