Solar energy concentrated heat collecting and supplying hot water system

Abstract

This utility model relates to a tiered heating hot water system with centralized solar heat collection and supply, belonging to the field of water heater technology. The system includes a solar water heating unit and an auxiliary heat source hot water unit. The solar water heating unit contains multiple solar water heater modules. Cold water from a cold water source is collected by each solar water heater module and then discharged through a primary outlet pipe. The auxiliary heat source hot water unit contains multiple hot water storage tanks that circulate heat with the auxiliary heat source. Hot water from each storage tank is collected and discharged through a secondary outlet pipe. The primary outlet pipe connects to the cold water supply pipeline via a mixing valve, supplying water to each hot water storage tank. One secondary outlet pipe replenishes the hot water collection tanks via a heat storage circulation pipeline equipped with a heat storage circulation pump, while the other pipe passes through a point of use and connects to the cold water supply pipeline via a return water circulation pipeline equipped with a return water circulation pump. This utility model reduces the volume of the auxiliary heat source hot water storage tanks and provides freeze protection for the solar water collection tanks.

Description

Technical Field

[0001] This utility model relates to a graded heating hot water system, and more particularly to a graded heating hot water system with centralized solar (solar thermal, photovoltaic) heat collection and centralized heating, belonging to the field of water heater technology. Background Technology

[0002] Chinese patents with application numbers 202223513432.1 and 202223513434.0 disclose integrated self-regulating solar water heating units with heat collection and storage, and direct-heating heat pump variable-capacity constant-temperature hot water systems, each with their own advantages. In recent years, how to organically combine solar energy and heat pumps to fully leverage their advantages has become a research topic of concern in the industry.

[0003] Search results show that Chinese patent applications CN202120658779.1 and CN201410004432.X disclose centralized hot water systems based on solar energy and air source heat pumps, and a centralized heating system that combines CO2 heat pumps with solar energy, respectively. In essence, both simply achieve simultaneous use of two heating methods by sharing a hot water storage tank between solar energy and the heat pump, without achieving an organic integration. Furthermore, Chinese patent document CN201811294869.6 discloses a control system and method for a centralized hot water system using solar energy and air source heat pumps. Its technical solution aims to achieve flexible control of the centralized hot water system using solar energy and air source heat pumps, thereby significantly reducing energy consumption and environmental pollution while effectively ensuring the amount of hot water needed by users. However, in reality, this technical solution is an open system connected to the atmosphere, which cannot ensure water hygiene. Moreover, its heat pump heat source can only heat the second water tank connected to it, and cannot heat the first water tank connected to the solar energy system. Therefore, the volume of the water tanks is not effectively utilized, resulting in low thermal energy utilization. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of the existing technology by organically combining solar energy with an auxiliary heat source hot water unit. This proposes a graded heating hot water system that uses the hot water collection tank of the solar water water unit as the storage tank of the auxiliary heat source hot water unit, thereby meeting the hot water demand.

[0005] To achieve the above objectives, the basic technical solution of this utility model's graded heating hot water system for centralized solar heat collection and supply is as follows:

[0006] Includes solar water heating units and auxiliary heat source water heating units;

[0007] The solar water heating unit contains multiple solar energy collection and conversion devices and hot water collection tanks. Cold water from a cold water source is collected in each hot water collection tank and then discharged through a primary outlet pipe.

[0008] The auxiliary heat source hot water unit contains multiple hot water storage tanks connected in parallel to form a heat exchange cycle with the auxiliary heat source. After the hot water storage tanks are collected, hot water is output through a secondary outlet pipe.

[0009] The primary water outlet pipe and the cold water supply pipe supply water to each hot water storage tank after passing through the mixing valve. One of the secondary water outlet pipes supplies water to the hot water collection tank through the hot water storage circulation pipe with a hot water storage circulation pump, and the other pipe passes through the water point and then leads to the cold water supply pipe through the circulation return pipe with a return water circulation pump.

[0010] This invention organically combines a solar water heating unit with an auxiliary heat source water heating unit. The control of the auxiliary heat source is similar to existing technologies. During operation: when the water temperature in the storage tank is ≥ the set hot water outlet temperature (usually 55℃), the heat exchange cycle is controlled and does not operate; when the water temperature in the storage tank is ≤ the set hot water outlet temperature - a predetermined temperature difference (e.g., 55℃ - 5℃), the heat exchange cycle operates under control until the water temperature in the storage tank is ≥ the set hot water outlet temperature. Under these conditions, the following operating mode can be easily achieved:

[0011] Solar-heated hot water supply method 1: When the water temperature in the solar water heater tank is less than or equal to the set outlet temperature of the mixing valve, the cold water from the cold water source passes through the solar water heater, is collected to the first-level outlet pipe, and then goes through the mixing valve to each storage tank for additional heating before being supplied to the point of use via the second-level outlet pipe.

[0012] Solar-heated hot water supply method two: When the water temperature in the solar water heater tank is greater than the set outlet temperature of the mixing valve, the cold water from the cold water source passes through the solar water heater, is collected in the first-stage outlet pipe, and together with the supplemented cold water, passes through the mixing valve to each hot water storage tank, and then provides hot water to the point of use through the second-stage outlet pipe.

[0013] C. Auxiliary heat source utilizes solar water heater storage tank for heat storage - When the light conditions are poor and the solar water heater storage tank temperature is ≤ the set heat storage temperature (usually 43℃) - the predetermined temperature difference, the auxiliary heat source is controlled to circulate the hot water in its storage tank with the solar water heater storage tank; until the solar water heater storage tank temperature is ≥ the set heat storage temperature, the circulation stops, and hot water is supplied to the water point through the secondary outlet pipe.

[0014] D. Hot water supply method 1 after circulating water return - When the water temperature of the solar water heater tank is less than or equal to the set outlet water temperature of the mixing valve, the circulating water returns through the solar water heater, is collected to the first-level outlet pipe, and then goes through the mixing valve to each hot water storage tank for supplementary heating. After that, hot water is supplied to the water point through the second-level outlet pipe.

[0015] E. Hot water supply method two after circulating water return - When the water temperature of the solar water heater is greater than the set outlet temperature of the mixing valve, the circulating water passes through the solar water heater, is collected to the first-level outlet pipe, and together with the supplemented cold water, passes through the mixing valve to each hot water storage tank, and then supplies hot water to the water point through the second-level outlet pipe.

[0016] Therefore, by adopting this invention, the solar water heater not only absorbs and converts solar energy but also serves as part of the auxiliary heat source storage tank. This allows the solar water heating unit and the auxiliary heat source water heating unit to be organically combined. While maintaining the same hot water supply capacity, the volume of the auxiliary heat source storage tank is reduced compared to existing technologies, thereby reducing heat loss and lowering the initial investment of the system to some extent. Furthermore, the auxiliary heat source can provide freeze protection for the solar water heater.

[0017] Furthermore, the solar water heating unit and the auxiliary heat source water heating unit are respectively a non-powered solar water heating unit and an air source heat pump water heating unit.

[0018] Furthermore, the non-powered solar water heating unit contains multiple sets of parallel solar water heater module groups. Each solar water heater module group is composed of multiple solar collectors that serve as solar energy collection and conversion devices and corresponding hot water collection tanks connected in series.

[0019] Furthermore, the air source heat pump water heating unit contains multiple hot water storage tanks. The circulation outlets at the bottom of each hot water storage tank are collected and then passed through the heat exchange return pipeline to the heat pump circulation pump, which leads to the heat pump water heater. The heat exchange output pipelines then lead to the circulation inlet in the middle of each hot water storage tank, thus connecting them in parallel and forming a heat exchange cycle with the heat pump water heating unit.

[0020] Further: The cold water supply pipeline branching from the primary outlet pipe and the main cold water pipe passes through a mixing valve and then branches through a water replenishment pipeline to supply water to the top of each hot water storage tank. The secondary outlet pipe passes through the front and rear hot water storage circulation pipelines equipped with a hot water storage circulation pump, and then branches to replenish water to the hot water collection tank of each solar water heater module group.

[0021] Furthermore, the solar water heating unit and the auxiliary heat source water heating unit are respectively a photovoltaic water heating unit and an air source heat pump water heating unit.

[0022] Furthermore: the solar energy collection and conversion device of the photovoltaic hot water unit is a photovoltaic module that collects solar energy and converts it into electrical energy, and the hot water collection tank is a photovoltaic hot water collection tank equipped with an electric heating device. The electrical energy output by the photovoltaic module heats the water in multiple parallel hot water collection tanks through the corresponding electric heating device.

[0023] Further: The auxiliary heat source hot water unit is a gas or oil heating hot water unit. Attached Figure Description

[0024] Figure 1 This is a structural schematic diagram of Embodiment 1 of the present invention.

[0025] Figure 2 This is a structural schematic diagram of Embodiment 2 of this utility model. Detailed Implementation Example 1

[0026] This embodiment describes a non-powered, centralized solar thermal collection and heating system for tiered hot water heating, as shown below. Figure 1 As shown, it includes a non-powered solar water heating unit in Zone 1 and an air source heat pump water heating unit in Zone 2.

[0027] The solar water heating unit contains multiple sets of parallel solar water heater module groups. Each solar water heater module group consists of multiple solar collectors 1.2, which serve as solar energy collection and conversion devices, and corresponding hot water collection tanks 1.2 connected in series. Cold water from the tap water source passes through the main cold water pipe 9, the main cold water pipe 8, and each set of branch cold water pipes 4, and then through each solar water heater module SL. After being collected, the water is discharged through the primary outlet pipe 5.

[0028] The air source heat pump water heating unit contains multiple hot water storage tanks SX. The circulation outlets at the bottom of each hot water storage tank SX are collected and then pass through the heat exchange return pipe 11 to the heat pump circulation pump HPB, which leads to the heat pump water heater HPWH. The heat exchange output pipes 12 then lead to the circulation inlet in the middle of each hot water storage tank SX, thus connecting them in parallel and forming a heat exchange cycle with the heat pump water heater HPWH. The water outlets at the top of each hot water storage tank SX are collected and then output as hot water through the secondary water outlet pipe 1.

[0029] The primary outlet pipe 5 branches off from the main cold water pipe 9, and the cold water supply pipe 7, after passing through the mixing valve, branches off through the replenishment pipe 6 to replenish water to the top of each solar water heater storage tank SX. The secondary outlet pipe 1, after passing through the front and rear heat storage circulation pipes 2 and 3 equipped with the heat storage circulation pump XPB, branches off to replenish water to the heat collection tanks of each solar water heater module group. Furthermore, the secondary outlet pipe 1, after passing through the water usage point, also passes through the circulation return pipe 10 equipped with the return water circulation pump HSB to the cold water supply pipe 7, and finally to the mixing valve.

[0030] In this way, the air source heat pump becomes an auxiliary heat source for the solar water heating system. The water temperature control in its storage tank is basically the same as existing technology: when the water temperature in the storage tank is ≥ 55℃ (the set hot water outlet temperature), the heat exchange cycle of the heat pump water heater is not working; when the water temperature in the storage tank is ≤ 55℃ - 5℃ (the set hot water outlet temperature), the heat exchange cycle of the heat pump water heater is working until the water temperature in the storage tank is ≥ 55℃ (the set hot water outlet temperature), then it stops working. By controlling the heat storage circulation pump and the return water circulation pump as needed, various methods of supplying hot water after solar heating and after circulating return water can be realized according to different application scenarios, as well as the use of the solar water heater tank for heat storage as an auxiliary heat source.

[0031] This embodiment refers to the basic requirements of GB 50015, GB / T 29158, and T / CECS 489. Its design concept of a "centralized solar water heating system" refers to a solar water heating system that centrally collects solar thermal energy and then centrally configures an auxiliary heat source. A "non-powered solar water heater (module)" refers to a modular solar water heating device that integrates solar thermal collection, storage, and exchange through natural circulation, conduction, and convection heat transfer. A "staged heating hot water system" means that the solar and auxiliary heat source heating systems do not share a hot water storage tank. Water is first heated by solar energy and then sent to the auxiliary heat source heating system. When the hot water temperature is insufficient, the auxiliary heat source heats it to the set temperature. Because the non-powered solar water heater tank also serves as a supplement to the auxiliary heat source hot water storage tank, when sunlight conditions are not ideal, the non-powered solar water heater tank also becomes part of the auxiliary heat source's hot water storage tank through a heat storage circulation pump, reducing the volume of the auxiliary heat source's separately configured hot water storage tank. During peak hot water usage periods, it can ensure that hot water supply demand is met. Taking a heat storage set temperature of 43℃ as an example: when the solar water heater tank T1 is greater than or equal to the heat storage set temperature of 43℃, the heat storage circulation pump XRB does not work; when the time of water use is less than or equal to 3 hours and the solar water heater tank T1 is less than or equal to the heat storage set temperature of 43℃ - 5℃, the heat storage circulation pump XRB is started until T1 is greater than or equal to 43℃, and then the heat storage circulation pump XRB is turned off.

[0032] In addition, this embodiment also provides anti-freeze protection for the non-powered solar water heater. In extremely cold, sunless weather such as snowfall or nighttime frost, to prevent the domestic water temperature in the non-powered solar water heater storage tank from dropping below 0°C and causing the tank to freeze and break, the following measures are taken: Taking a 4°C anti-freeze protection temperature for the non-powered solar water heater storage tank as an example: when the solar water heater storage tank T1 ≤ 4°C, the heat storage circulation pump XRB is activated; when the solar water heater storage tank T1 ≥ 4°C + 8°C, the heat storage circulation pump XRB is deactivated. Example 2

[0033] The solar-powered centralized heat collection and centralized heating staged heating hot water system in this embodiment is as follows: Figure 2As shown, the difference from Embodiment 1 is that the solar water heating unit in Zone 1 is actually a photovoltaic water heating unit, similar to the prior art. The solar energy collection and conversion device of this unit is a photovoltaic module that converts collected solar energy into electrical energy. The hot water collection tank is actually a photovoltaic hot water collection tank equipped with electric heating devices. The electrical energy output by the photovoltaic module heats the water in multiple parallel hot water collection tanks through the corresponding electric heating devices. Other technical features and advantages are the same as in Embodiment 1, and will not be repeated.

[0034] In addition to the embodiments described above, this utility model may have other implementations. For example, the auxiliary heat source hot water unit may also be a gas or oil heating hot water unit. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by this utility model.

Claims

1. A graded heating hot water system with centralized solar heat collection and supply, comprising a solar hot water unit and an auxiliary heat source hot water unit; characterized in that: The solar water heating unit contains multiple solar energy collection and conversion devices and hot water collection tanks. Cold water from a cold water source is collected in each hot water collection tank and then discharged through a primary outlet pipe. The auxiliary heat source hot water unit contains multiple hot water storage tanks connected in parallel to form a heat exchange cycle with the auxiliary heat source. After the hot water storage tanks are collected, hot water is output through a secondary outlet pipe. The primary water outlet pipe and the cold water supply pipe supply water to each hot water storage tank after passing through the mixing valve. One of the secondary water outlet pipes supplies water to the hot water collection tank through the hot water storage circulation pipe equipped with a hot water storage circulation pump, and the other pipe passes through the water point and then leads to the cold water supply pipe through the circulation return pipe equipped with a return water circulation pump.

2. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 1, characterized in that: The solar water heating unit and the auxiliary heat source water heating unit are respectively a non-powered solar water heating unit and an air source heat pump water heating unit.

3. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 2, characterized in that: The non-powered solar water heating unit contains multiple sets of parallel solar water heater module groups. Each solar water heater module group is composed of multiple solar collectors that serve as solar energy collection and conversion devices and corresponding hot water collection tanks connected in series.

4. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 3, characterized in that: The air source heat pump water heating unit contains multiple hot water storage tanks. The circulation outlets at the bottom of each hot water storage tank are collected and then flow through the heat exchange return pipeline to the heat pump circulation pump, which then flows to the heat pump water heater. The heat exchange output pipelines then flow to the circulation inlet in the middle of each hot water storage tank, thus connecting them in parallel and forming a heat exchange cycle with the heat pump water heater.

5. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 4, characterized in that: The primary outlet pipe and the cold water supply pipe branching off from the main cold water pipe pass through a mixing valve, and then through a water replenishment pipe branching off to supply water to the top of each hot water storage tank. The secondary outlet pipe passes through the front and rear hot water storage circulation pipes equipped with a hot water storage circulation pump, and then branches off to replenish water to the hot water collection tank of each solar water heater module group.

6. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 1, characterized in that: The solar water heating unit and the auxiliary heat source water heating unit are respectively a photovoltaic water heating unit and an air source heat pump water heating unit.

7. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 6, characterized in that: The solar energy collection and conversion device of the photovoltaic hot water unit is a photovoltaic module that collects solar energy and converts it into electrical energy. The hot water collection tank is a photovoltaic hot water collection tank equipped with an electric heating device. The electrical energy output by the photovoltaic module heats the water in multiple parallel hot water collection tanks through the corresponding electric heating device.

8. The graded heating hot water system for centralized solar heat collection and centralized heating according to claim 1, characterized in that: The auxiliary heat source hot water unit is a gas or oil heating hot water unit.

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