Heating anti-freezing system of all-glass vacuum tube heat collector

Abstract

The utility model relates to a solar heating system, in particular to the technical field of solar heating anti-freezing, in particular to a heating anti-freezing system of an all-glass vacuum tube heat collector, which solves the problem of over-high anti-freezing energy consumption, improves the anti-freezing capability, ensures the system stability and improves the anti-freezing effect. Comprising a solar heat collector, a buffer water tank, a heat collection circulating pump and an electric three-way valve, a water inlet of the buffer water tank is communicated with an outlet of the solar heat collector through a water supply pipeline, a water outlet of the buffer water tank is sequentially communicated with an inlet of the heat collection circulating pump and an inlet of the electric three-way valve, and a first outlet and a second outlet of the electric three-way valve are jointly communicated with a water return pipeline through a first branch and a second branch respectively. The other end of the water return pipeline is communicated with a water return port of the solar heat collector; a check valve is arranged on the first branch, and the buffer water tank communicates with a heating tail end through a heat supply circulation pipeline.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar energy heating system especially to the technical field of solar energy heating anti-freezing, and specifically relates to a full-glass vacuum tube heat collector heating anti-freezing system. BACKGROUND

[0002] Most of the existing solar energy heating systems in northern rural areas are direct heat exchange systems, that is, water directly flows in the glass tube, enters the buffer tank after being heated by solar radiation, or directly enters the terminal for heating. Due to the low temperature in northern rural areas, freeze damage has become one of the most common problems in the system operation process, and the system stability is extremely low in severe cold seasons. In the existing solar energy heating systems on the market, the common anti-freezing logic is anti-freezing circulation + heat tracing band or emptying anti-freezing.

[0003] The control logic of the anti-freezing circulation is: when the temperature at the end of the heat collection circulation pipeline is ≤ the anti-freezing circulation starting value (generally defaulting to 4℃, which can be adjusted), the heat collection circulation pump starts; when the temperature at the end of the heat collection circulation pipeline is > the anti-freezing circulation starting value + 4℃ (which can be adjusted), the heat collection circulation pump stops; the heat tracing band anti-freezing control logic is generally: when the temperature at the end of the heat collection circulation pipeline is ≤ the heat tracing band starting value (generally defaulting to 4℃, which can be adjusted), the heat tracing band starts; when the temperature at the end of the heat collection circulation pipeline is > the heat tracing band starting value + 4℃ (which can be adjusted), the heat tracing band is turned off. This anti-freezing mode guarantees the safety of the heat collector and the circulation pipeline, and the disadvantage is that when the temperature at the end of the heat collector circulation pipeline is lower than the set value, the anti-freezing circulation and the heat tracing band are started at the same time, which causes certain energy waste and increases the system operation cost.

[0004] Another common anti-freezing method is emptying anti-freezing, which is divided into timing emptying and self-emptying by gravity. The timing emptying system is generally set at 18:00 Beijing time, and an emptying valve (as shown in the figure) is automatically opened to empty the water in the heat collection circulating pipeline. To avoid pipeline explosion, the system starts timing water filling at 6:00 the next day. The disadvantage of this anti-freezing mode is that the system will empty the pipeline at the set time throughout the heating season regardless of the ambient temperature, and can only be emptied at the same set time, which cannot guarantee that the pipeline is emptied before freezing every day. Another anti-freezing method is that the outlet of the water pump is not provided with a check valve, and when the heat collection circulating pump does not meet the temperature difference circulation starting condition, the water in the pipeline flows back to the water tank. This method can ensure that the water in the pipeline is not frozen, whether it is day or night, as long as the heat collection circulating pump does not run. The above two emptying anti-freezing methods can only ensure that the circulating pipeline is not frozen, and most of the water in the evacuated heat collector vacuum tube still exists in the vacuum tube. After the pipeline is emptied, the vacuum tube relies on the basic temperature of the medium in the tube and its own heat preservation for anti-freezing. In extremely cold weather (below-20℃), the water in the vacuum tube will be frozen, and the expansion of its volume will cause the vacuum tube glass to crack. Therefore, the all-glass vacuum tube solar heating system using the emptying anti-freezing method cannot guarantee the stability of the entire system. When the pipeline is emptied, the pipeline temperature cannot be accurately obtained, and if the heating band needs to be started, it can only be controlled by intermittent start-stop. Practical new type content

[0005] The utility model provides a kind of all-glass vacuum tube heat collector heating anti-freezing system, in solving the problem that anti-freezing energy consumption is too high, improve anti-freezing capacity, guarantee system stability.

[0006] The utility model is realized by the following technical solutions:

[0007] An all-glass vacuum tube heat collector heating anti-freezing system, comprising a solar heat collector, a buffer tank, a heat collection circulating pump and an electric three-way valve.

[0008] The water inlet of the buffer tank is communicated with the outlet of the solar heat collector through a water supply pipeline, and the water outlet of the buffer tank is communicated with the inlet of the heat collection circulating pump and the electric three-way valve in turn, and the No. 1 outlet and No. 2 outlet of the electric three-way valve are communicated with a return water pipeline through a No. 1 branch and a No. 2 branch respectively, and the other end of the return water pipeline is communicated with the return water inlet of the solar heat collector.

[0009] A check valve is arranged on the No. 1 branch, and the buffer tank is communicated with a heating terminal through a heat supply circulating pipeline.

[0010] The outlet of the solar heat collector is provided with a heat collector outlet temperature sensor, the end of the return water pipeline is provided with a heat collection circulating terminal temperature sensor, and the buffer tank is provided with a water tank temperature sensor.

[0011] Further, the heat collecting circulating pump, the heat collector outlet temperature sensor, the heat collecting circulating end temperature sensor and the water tank temperature sensor are electrically connected to the controller respectively.

[0012] Further, a heat tracing band is arranged on the outer wall of the water return pipeline.

[0013] Further, the buffer water tank is further communicated with an auxiliary heat source.

[0014] Further, a heating circulating pump is arranged on the heating circulating pipeline.

[0015] The beneficial effects achieved by the utility model compared with the prior art are as follows:

[0016] 1. The full-glass vacuum tube heat collector heating anti-freezing system increases the night environment temperature detection on the basis of the traditional emptying anti-freezing logic, when the environment temperature is lower than -20 DEG C, the electric three-way valve connects the check valve, starts the anti-freezing circulation, avoids the vacuum tube from being frozen and cracked under the extremely low temperature, the vacuum tube has no freezing risk in the daytime, the gravity self-emptying mode is used for anti-freezing, the anti-freezing energy consumption of the system is reduced to the maximum, and the system stability is improved.

[0017] 2. In order to empty completely in the daytime, the heat collecting circulating pipeline does not pass through the check valve, when the night anti-freezing circulation and the heat tracing band start, the end temperature of the heat collecting circulating pipeline needs to be accurately acquired, and the heat collecting circulating pipeline needs to pass through the check valve. An electric three-way valve is arranged between the heat collecting circulating pump and the check valve to realize the switching of two circuits.

[0018] 3. During the night time period, the heat tracing band is used as the supplement of the anti-freezing circulation, the starting temperature of the heat tracing band is lower than that of the anti-freezing circulation, the two measures are avoided from starting simultaneously, and energy waste is avoided.

[0019] 4. The full-glass vacuum tube heat collector heating anti-freezing system puts forward an anti-freezing control logic taking the emptying anti-freezing as the main part, the anti-freezing circulation and the heat tracing band as the supplement, greatly reduces the anti-freezing energy consumption of the full-glass vacuum tube solar heating system, considers the anti-freezing effects of the heat collector and the circulating pipeline, and improves the system stability. DRAWINGS

[0020] Figure 1 It is a schematic view of the full-glass vacuum tube heat collector heating anti-freezing system.

[0021] In the drawing: 1, solar heat collector, 2, buffer water tank, 3, heat collecting circulating pump, 4, heating circulating pump, 5, heating end, 6, heat tracing band, 7, electric three-way valve, 8, auxiliary heat source, 9, controller, 10, check valve. DETAILED DESCRIPTION

[0022] With reference to the accompanying drawings: clearly, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of the present application.

[0023] In the description of the utility model, it needs to be understood that the terms "front", "back", "up", "down", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0024] As shown in Figure 1 The present embodiment discloses a kind of full glass vacuum tube collector heating freeze-proof system, it mainly includes controller 9, solar collector 1, buffer water tank 2, heat collecting circulating pump 3, heating terminal 5 and electric three-way valve 7 etc.Structural components.Communication solar collector 1 outlet is connected by water supply pipeline to the water inlet of buffer water tank 2, the water outlet of buffer water tank 2 is sequentially connected heat collecting circulating pump 3 and the inlet of electric three-way valve 7, the No.1 outlet and No.2 outlet of electric three-way valve 7 are connected by No.1 branch and No.2 branch respectively, and check valve 10 is arranged on No.1 branch, the other end of return water pipeline is connected to the return water inlet of solar collector 1, and return water pipeline and water supply pipeline jointly constitute heat collecting circulating pipeline, and heat tracing band 6 is wound on the outer wall of heat collecting circulating pipeline.Buffer water tank 2 is connected by heating circulating pipeline with heating terminal 5, and heating circulating pump 4 is arranged on heating circulating pipeline.In order to prevent insufficient heating at night in winter, buffer water tank 2 is also connected with auxiliary heat source 8, which generally uses air source heat pump.

[0025] In order to realize various temperature conditions control, heat collector outlet temperature sensor is arranged at the outlet of solar collector 1, heat collecting circulating terminal temperature sensor is arranged at the end of return water pipeline, water tank temperature sensor is arranged in buffer water tank 2, and outdoor environment temperature sensor is installed outdoors. Outdoor environment temperature sensor, heat collecting circulating pump 3, heat collector outlet temperature sensor, heat collecting circulating terminal temperature sensor and water tank temperature sensor are electrically connected to controller 9. Heat collecting circulating terminal temperature sensor can detect solar collector 1 outlet temperature T1, water tank temperature sensor can detect water temperature T3 in buffer water tank 2, heat collecting circulating terminal temperature sensor can detect water temperature T2 at the end of return water pipeline, and outdoor environment temperature sensor can detect outdoor ambient temperature T5.

[0026] Taking the use in winter in northern China such as Liaoning, Heilongjiang and other places as an example, the anti-freezing control logic of the full-glass vacuum tube collector heating anti-freezing system is as follows:

[0027] 1. In the daytime period (8:00~18:00, adjustable), the No. 2 outlet of the electric three-way valve 7 is connected to the No. 2 branch, and the heat collecting circulating pump 3 operates according to the temperature difference circulation logic,

[0028] When T1-T3≥8℃ (adjustable), the heat collecting circulating pump 3 starts, and the solar heat collector 1 normally supplies heat to the buffer water tank 2;

[0029] When T1-T3<3℃ (adjustable), the heat collecting circulating pump 3 stops, and at this time, the water in the heat collecting circulating pipeline returns to the buffer water tank 2 by relying on its own gravity when the temperature difference circulation condition is not met;

[0030] This stage does not consume energy for daytime anti-freezing;

[0031] 2. In the nighttime period (18:00~next day 6:00), when T5<-20℃, the No. 2 outlet of the electric three-way valve 7 is connected to the second branch and the check valve, so as to ensure that there is water in the return pipeline and facilitate the detection of T2, and the heat collecting circulating pump 3 starts and operates according to the anti-freezing circulation logic after 30 minutes;

[0032] When T2≤8℃ (adjustable), the heat collecting circulating pump 3 starts to circulate the hot water in the buffer water tank 2 into the solar heat collector 1;

[0033] When T2>10℃ (adjustable), the heat collecting circulating pump 3 stops;

[0034] This stage can effectively prevent the vacuum tube from being frozen by extremely low temperature at night; if T5≥-20℃, the vacuum tube has no risk of freezing, and the heat collecting circulating pump 3 is started at Beijing time 6:00 (adjustable) to complete the water filling of the system, and the heat collecting circulating pump 3 is stopped after 20 minutes to operate according to the first rule;

[0035] 3. In the nighttime period (18:00~next day 6:00), when T2≤4, the heat tracing band 6 is started to heat the heat collecting circulating pipeline;

[0036] When T2>8℃ (adjustable), the heat tracing band 6 is closed;

[0037] This stage is to prevent the heat collecting circulating pipeline from being frozen due to the failure of the auxiliary heat source 8 or the anti-freezing circulation.

[0038] The all-glass evacuated tube collector heating anti-freezing system proposed in the embodiment provides an anti-freezing control logic mainly based on evacuation anti-freezing, supplemented by anti-freezing circulation and heating band 6, which greatly reduces the anti-freezing energy consumption of the all-glass evacuated tube solar heating system, takes into account the anti-freezing effect of the collector and the circulating pipeline, and improves the stability of the system.

Claims

1. A freeze protection system for a full glass evacuated tube collector, comprising: The solar energy collector, the buffer water tank, the heat collecting circulating pump and the electric three-way valve are included. The water inlet of the buffer water tank is communicated with the outlet of the solar energy collector through a water supply pipeline, the water outlet of the buffer water tank is communicated with the inlet of the heat collecting circulating pump and the electric three-way valve in sequence, the No.1 outlet and the No.2 outlet of the electric three-way valve are respectively communicated with a return water pipeline through a No.1 branch and a No.2 branch, and the other end of the return water pipeline is communicated with the return water inlet of the solar energy collector. A check valve is arranged on the No.1 branch, and the buffer water tank is communicated with a heating terminal through a heat supply circulating pipeline. The outlet of the solar energy collector is provided with a collector outlet temperature sensor, the end of the return water pipeline is provided with a heat collecting circulating terminal temperature sensor, and the buffer water tank is provided with a water tank temperature sensor.

2. The all-glass evacuated-tube collector hydronic freeze protection system of claim 1, wherein, A controller is further included, and the heat collecting circulating pump, the collector outlet temperature sensor, the heat collecting circulating terminal temperature sensor and the water tank temperature sensor are electrically connected with the controller.

3. The all-glass evacuated-tube collector hydronic freeze protection system of claim 1, wherein, A heat tracing band is arranged on the outer wall of the return water pipeline.

4. The all-glass evacuated-tube collector hydronic freeze protection system of claim 3, wherein, The buffer water tank is further communicated with an auxiliary heat source.

5. The all-glass evacuated-tube collector hydronic anti-freeze system according to any one of claims 1-4, wherein, A heating circulating pump is arranged on the heat supply circulating pipeline.

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