Clean energy supply system

Abstract

The invention relates to the technical field of energy supply, and discloses a clean energy supply system which comprises a cooling tower water circulation system, an air source heat pump water circulation system, an air conditioner water circulation system, a water source heat pump unit and an automatic control valve. Wherein the cooling tower water circulation system comprises a cooling tower unit and a cooling tower circulating pump; the air source heat pump water circulation system comprises an air source heat pump unit and an air source circulating pump; independent heating operation of the air source heat pump unit, series operation of the air source heat pump unit and the water source heat pump unit and summer independent refrigeration and parallel operation of the water source heat pump unit and the air source heat pump unit are controlled through switching of the automatic control valve; wherein the air source heat pump unit and the water source heat pump unit are coupled in series and are used for increasing the heating capacity. By means of the system, efficient energy supply in winter and summer is achieved through valve switching.

Description

Technical Field

[0001] The present invention relates to the field of energy supply technology, and in particular to a clean energy supply system. Background Art

[0002] Under winter heating conditions, the heating capacity of an air-source heat pump unit is related to the outdoor air environment. Theoretically, for every 1°C drop in outdoor temperature (evaporating temperature), its heating capacity decreases by approximately 3%. At the same time, with the heat pump water supply temperature (condensing temperature) remaining unchanged, its heating efficiency also decreases by approximately 3%. To meet the heating capacity under winter design conditions, the design and selection of air-source heat pump units need to be modified based on the winter heating outdoor temperature. The final number of air-source heat pump units designed will be significantly increased, resulting in increased building space and construction costs. In actual use, the outdoor temperature during the heating season is often higher than the design operating temperature. Therefore, for most of the heating season, some air-source heat pump units are idle and underutilized. At the same time, during winter conditions, the cooling tower chillers used for summer cooling are also idle. Summary of the Invention

[0003] The present invention is made to solve the above-mentioned technical problems. Its purpose is to provide a clean energy supply system. Through valve switching, it solves the problems of air source heat pump units' reduced heating capacity and efficiency due to the decrease in outdoor ambient temperature in winter, resulting in excessive equipment selection, increased construction costs and insufficient unit utilization.

[0004] In order to achieve the above-mentioned purpose, the present invention provides a clean energy supply system, comprising: a cooling tower water circulation system, an air source heat pump water circulation system, an air conditioning water circulation system, a water source heat pump unit and an automatic control valve; wherein,

[0005] The cooling tower water circulation system includes a cooling tower unit and a cooling tower circulation pump;

[0006] The air source heat pump water circulation system includes an air source heat pump unit and an air source circulation pump;

[0007] The switching of the automatic control valve controls the independent heating operation of the air source heat pump unit, the series operation of the air source heat pump unit and the water source heat pump unit, and the independent cooling and parallel operation of the water source heat pump unit and the air source heat pump unit; wherein,

[0008] The air source heat pump unit and the water source heat pump unit are coupled in series to increase the heating capacity.

[0009] Preferably, the air conditioning water circulation system includes an air conditioning terminal and an air conditioning circulation pump;

[0010] The air source heat pump water circulation system realizes three operation modes through the switching of the air source circulation pump and the automatic control valve; wherein,

[0011] The air source water circulation system is connected in parallel with the water source heat pump unit and assists the water source heat pump unit in refrigeration;

[0012] When the ambient temperature is greater than or equal to -5°C, the air source water circulation system independently generates heat;

[0013] When the ambient temperature is lower than -5°C, the air source water circulation system and the water source heat pump unit are connected in series for heating.

[0014] Preferably, the coupling system of the air source heat pump unit and the water source heat pump unit is divided into four operating conditions throughout the year according to the ambient temperature, namely summer operating condition I, summer operating condition II, winter operating condition I and winter operating condition II; wherein,

[0015] The summer operating condition I is a partial load in summer, and the water source heat pump unit operates in cooling mode alone;

[0016] When the summer working condition II is the design daily load, the air source heat pump and the water source heat pump are connected in parallel for cooling;

[0017] The winter operating condition I is when the ambient temperature is greater than or equal to -5°C, the air source heat pump alone generates heat;

[0018] The winter working condition II is when the ambient temperature is less than -5°C, and the air source heat pump component and the water source heat pump component are connected in series to generate heat.

[0019] Preferably, the cooling tower water circulation system operates in summer operating conditions I and summer operating conditions II.

[0020] Preferably, the automatic control valve includes: valve K1, valve K2, valve K3 and valve K4; wherein,

[0021] The valve K1 is used to control the connection between the water source heat pump unit and the air conditioner terminal;

[0022] The valve K2 is used to control the connection between the air source heat pump and the air conditioning terminal;

[0023] The valve K3 is used to control the connection between the cooling tower unit and the water source heat pump unit;

[0024] The valve K4 is used to control the series connection of the air source heat pump assembly and the water source heat pump assembly;

[0025] In the summer operating condition I, the valve K1 and the valve K3 are opened, and the valve K2 and the valve K4 are closed;

[0026] In the summer operating condition II, the valve K1 and the valve K3 are opened, and the valve K2 and the valve K4 are closed;

[0027] In the winter operating condition I, the valve K2 and the valve K3 are opened, and the valve K1 and the valve K4 are closed;

[0028] In the winter operating condition II, the valve K2 and the valve K4 are opened, and the valve K1 and the valve K3 are closed.

[0029] Preferably, in the winter operating condition I, the outlet water temperature of the air source heat pump unit is 44°C to 46°C;

[0030] In the winter operating condition II, the outlet water temperature of the air source heat pump unit is 19°C to 21°C, and the outlet water temperature of the water source heat pump unit is 44°C to 46°C.

[0031] Preferably, in the winter operating condition II, in the series heating mode of the air source heat pump and the water source heat pump unit, the temperature difference between the outlet water temperature of the air source heat pump and the inlet water temperature of the water source heat pump unit does not exceed 25°C.

[0032] Preferably, the water source heat pump unit discharges condensation heat through the cooling tower circulation pump under summer operating conditions I and summer operating conditions II;

[0033] The water source heat pump unit is used as a series heat source to improve heating efficiency under winter operating conditions I and winter operating conditions II.

[0034] Preferably, under summer operating conditions I and summer operating conditions II, the cooling tower water circulation system transports the cooling water cooled by the cooling tower to the inlet of the condenser of the water source heat pump unit through the cooling tower circulation pump, and returns the condensation heat generated by the water source heat pump unit to the cooling tower through the outlet of the condenser, thereby completing the cooling water system circulation volume of the water source heat pump unit.

[0035] Preferably, the air source heat pump unit is selected based on the minimum heating capacity under winter heating load and winter average temperature conditions.

[0036] According to the above description and practice, the clean energy supply system of the present invention has the following advantages compared with the traditional clean energy supply system:

[0037] 1. The system integrates summer cooling and winter heating functions to achieve cross-seasonal reuse of key equipment.

[0038] 2. In view of the low temperature working conditions in cold areas, the system adopts the series operation mode of air source heat pump and water source heat pump.

[0039] 3. The system realizes precise switching of operating modes through the coordinated work of automatic control valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a system principle diagram of a clean energy supply system involved in one embodiment of the present invention. DETAILED DESCRIPTION

[0041] The exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments can be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concepts of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0042] In addition, the accompanying drawings are only schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the figures represent the same or similar parts, and their repeated description will be omitted. It should be noted that in the present disclosure, the terms "including", "configured with", and "set on" are used to express open-ended inclusion and mean that in addition to the listed elements / components / etc., there may be additional elements / components / etc.; the terms "first", "second", etc. are used only as labels and are not intended to limit the number or order of their objects; the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction, and therefore should not be understood as limiting the present invention.

[0043] Unless otherwise specified or limited, the terms "mounted," "connected," and "connected" should be interpreted broadly. For example, they can refer to fixed, removable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; and internal communication between two components. Those skilled in the art will understand the specific meanings of these terms in the present invention based on the specific circumstances.

[0044] In this embodiment, a clean energy supply system is disclosed. Figure 1 The whole system principle of the clean energy supply system is shown.

[0045] Please refer to Figure 1The clean energy supply system in the present invention includes: a cooling tower water circulation system, an air source heat pump water circulation system, an air conditioning water circulation system, a water source heat pump unit and an automatic control valve. The cooling tower water circulation system includes a cooling tower unit and a cooling tower circulation pump. In summer, the cooled water is transported to the condenser inlet of the water source heat pump unit through the circulation pump. After absorbing the heat generated during the refrigeration process, it returns to the cooling tower through the condenser outlet to complete the heat dissipation cycle. The air source heat pump water circulation system includes an air source heat pump unit and an air source circulation pump, which switches between independent heating, series heating or parallel cooling modes according to the ambient temperature. The water source heat pump unit discharges condensation heat through the cooling tower in summer, and works in conjunction with the air source heat pump unit as an auxiliary heat source in winter. The automatic control valve switches between different combinations to achieve precise conversion between the four operating modes, ensuring system flexibility and efficiency.

[0046] Furthermore, the coupled system of the air-source heat pump unit and the water-source heat pump unit divides the annual operating mode into four operating conditions according to the ambient temperature: Summer Condition I, Summer Condition II, Winter Condition I, and Winter Condition II. Summer Condition I is when the summer is partially loaded. In order to improve the overall efficiency of summer cooling operation, only the water-source heat pump unit with relatively high cooling efficiency is used for cooling operation. Summer Condition II is the summer design daily load. At this time, the air-conditioning terminal load is relatively large. The water-source heat pump unit alone cannot meet the demand of the air-conditioning terminal load. The air-source heat pump unit and the water-source heat pump unit need to operate together to provide cooling capacity. Winter Condition I is when the outdoor environment is relatively high in winter, for example, when the outdoor temperature is ≥-5°C, the air-source heat pump unit operates alone for heating (water outlet temperature 45°C). Winter operating condition II is when the outdoor temperature is relatively low in winter, for example, when the outdoor temperature is less than -5℃, the heating efficiency and heating capacity of the air source heat pump unit will decrease. In order to improve the heating efficiency and heating capacity of the air source heat pump unit, the air source heat pump unit (outlet water temperature 20℃) and the water source heat pump unit will be connected in series for heating operation (outlet water temperature 45℃).

[0047] Furthermore, the switching logic of the automatic control valves is as follows: In summer operating conditions I / II, valves K1 and K3 are opened, and valves K2 and K4 are closed, allowing the water-source heat pump units to cool independently or in parallel. In winter operating condition I, valves K2 and K3 are opened, and valves K1 and K4 are closed, allowing the air-source heat pump units to heat independently. In winter operating condition II, valves K2 and K4 are opened, and valves K1 and K3 are closed, forming a series water path. Valve switching is triggered by a temperature sensor with a response time of less than or equal to 5 minutes, ensuring that the water path accurately matches the operating conditions.

[0048] Furthermore, the air conditioning water circulation system, consisting of air conditioning terminals and air conditioning circulation pumps, operates continuously year-round, delivering cold water in summer and hot water in winter. The air source heat pump water circulation system achieves three operating modes through valve switching: When the air conditioning load exceeds the capacity of the water source heat pump unit, the air source heat pump unit starts in parallel mode, jointly outputting cold water with the water source heat pump unit. Valves K1 and K3 open to supplement cooling capacity. When the ambient temperature is ≥-5°C, the air source heat pump unit operates independently, outputting 45°C hot water. Valves K2 and K3 open to directly supply heat to the air conditioning terminals. When the ambient temperature is <-5°C, the outlet water temperature of the air source heat pump unit drops to 20°C, serving as the low-temperature heat source for the water source heat pump unit. After secondary heating to 45°C, valves K2 and K4 open, forming a two-stage heating water circuit.

[0049] Furthermore, the cooling tower water circulation system operates under Summer Conditions I and II. The specific process is as follows: The cooling tower circulating pump transports cooling water, cooled by the cooling tower, to the condenser inlet of the water-source heat pump unit. The cooling water absorbs heat in the condenser and rises in temperature. It then returns to the cooling tower through the condenser outlet, where it is cooled again by spraying, forming a closed-loop circulation system. During summer operation, the cooling tower circulating pump ensures stable cooling of the water-source heat pump unit under high-temperature conditions. In winter, the system's cooling tower circulating pump and water circuit are shut down to avoid energy waste and equipment idleness.

[0050] Furthermore, the temperature control range under different winter operating conditions is as follows: When the ambient temperature is ≥ -5°C, the outlet water temperature of the air-source heat pump unit is maintained at 44°C to 46°C, directly meeting heating needs; when the ambient temperature is < -5°C, the outlet water temperature of the air-source heat pump unit drops to 19°C to 21°C, and the water-source heat pump unit performs secondary heating to 44°C to 46°C. Temperature fluctuations are controlled within ±1°C, ensuring heating stability and equipment life.

[0051] The selection of the air source heat pump unit and the cooling tower unit of the present invention is determined according to the load demand and operating conditions in winter and summer to ensure efficient matching of the system and actual application performance. In the winter selection, the air source heat pump unit is first compared based on the heating load and the average temperature: the heating capacity at an outlet water temperature of 45°C (conventional heating mode) and an outlet water temperature of 20°C (series heating mode) is calculated respectively, and the smaller value of the two is selected as the final selection basis, thereby ensuring that the air source heat pump unit can still stably provide heat under extreme low temperature conditions to avoid redundant or insufficient capacity. For the matching of summer cooling demand, the cooling capacity of the air source heat pump unit needs to be deducted from the total cooling load, and the remaining part is borne by the water source heat pump unit, and its capacity is determined accordingly; at the same time, the selection of the cooling tower unit needs to be strictly matched with the cooling capacity and condensation heat discharge requirements of the water source heat pump unit to ensure heat dissipation efficiency. The selection of circulating pumps is refined by scenario: the parameters of air-source circulating pumps are calculated based on their winter heating capacity and design temperature difference (e.g., a 5°C difference in supply and return water temperature); the flow rate and head of cooling tower circulating pumps are determined based on the cooling capacity of the cooling tower unit in summer and the design temperature difference of the condenser, and the appropriate head is selected in combination with the pipeline resistance characteristics; cooling tower circulating pumps are selected directly based on the design flow rate provided by the manufacturer, and their head is checked to see if it meets the hydraulic requirements of the water distribution system and pipelines. By precisely matching equipment capacity, independently designing winter and summer operating parameters, and configuring circulating power on demand, efficient system operation, energy consumption optimization, and cost savings can be achieved.

[0052] Furthermore, in the series heating mode of winter operating condition II, the temperature difference between the air-source heat pump outlet water temperature and the water-source heat pump unit inlet water temperature is limited to within 25°C. Based on the reverse Carnot cycle principle, the air-source heat pump heating coefficient formula is: ε = 1 + ε' = 1 + T0 / (TK - T0), where: ε is the heating coefficient; ε' is the cooling coefficient; TK is the condensing temperature; and T0 is the evaporating temperature.

[0053] From the above formula, in winter operating conditions, the lower the evaporation temperature (outdoor ambient temperature) T0, the lower the heating coefficient ε, and the higher the condensing temperature TK, the lower the heating coefficient. The heating efficiency of the air-source heat pump unit is set to ε0 = 4.5 under standard operating conditions (ambient temperature 7°C, outlet water temperature 45°C), ε1 = 2.88 under average winter temperature (ambient temperature -5°C, outlet water temperature 45°C), ε2 = 1.93 under low winter temperature (ambient temperature -12°C, outlet water temperature 45°C), and ε3 = 3.37 under low winter temperature (ambient temperature -12°C, outlet water temperature 20°C). The heating efficiency of the water-source heat pump unit is set to ε4 = 6.0 (low temperature side 20°C, high temperature side 45°C). When the outdoor temperature reaches -12°C, the heating efficiency of the air-source heat pump and water-source heat pump units in series heating operation (ambient temperature -12°C, air-source heat pump outlet water temperature 20°C, water-source heat pump unit outlet water temperature 45°C) is ε5 = 1 / (1 / 3.37 + 1 / 6) = 2.16, which is greater than 1.93 and higher than the heating efficiency ε2 under the winter low temperature (ambient temperature -12°C, outlet water temperature 45°C). At the same time, due to the reduction in the outlet water temperature of the air-source heat pump unit (from 45°C to 20°C), its heating capacity will increase by about 25% at the same outdoor temperature. This is achieved by adjusting the operating parameters of the air-source heat pump to avoid the efficiency drop of the water-source heat pump unit due to low-temperature water inlet.

[0054] Furthermore, in Summer Conditions I and II, the water-source heat pump unit removes condensation heat through the cooling tower circulation pump, performing cooling duties. In Winter Conditions I and II, it serves as an auxiliary heat source, receiving 20°C outlet water from the air-source heat pump and heating it to 45°C before outputting it. This equipment reuse design reduces the need for independent heat pumps and reduces costs.

[0055] Furthermore, under summer operating conditions I and summer operating conditions II, the cooling tower water circulation system uses a cooling tower circulation pump to send the cooling water cooled by the cooling tower to the inlet of the water source heat pump unit condenser, and sends the condensation heat of the summer air conditioning to the cooling tower through the outlet of the water source heat pump unit condenser to discharge heat, completing the cooling water system circulation of the water source heat pump unit.

[0056] Furthermore, air-source heat pump units are selected based on average winter temperatures, with selection parameters based on heating load and minimum heating capacity at average temperatures. A series heating mode compensates for the heating gap in low-temperature conditions, ensuring stable hot water output at 45°C even in -15°C temperatures, without the need for additional units.

[0057] To sum up, since air source heat pump units play a very important role in clean heating and energy conservation and emission reduction in winter, conventional air source heat pump units and water source heat pump units and corresponding circulating water pumps and other ancillary equipment are used. By controlling the automatic conversion of valves and the dual-purpose heat pump units, the heat pump units can achieve efficient operation modes under different working conditions, thereby saving building space, reducing project costs and operating expenses.

[0058] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A clean energy supply system, characterized in that: include: Cooling tower water circulation system, air source heat pump water circulation system, air conditioning water circulation system, water source heat pump unit and automatic control valve; among them, The cooling tower water circulation system includes a cooling tower unit and a cooling tower circulation pump; The air source heat pump water circulation system includes an air source heat pump unit and an air source circulation pump; The switching of the automatic control valve controls the independent heating operation of the air source heat pump unit, the series operation of the air source heat pump unit and the water source heat pump unit, and the independent cooling and parallel operation of the water source heat pump unit and the air source heat pump unit; wherein, The air source heat pump unit and the water source heat pump unit are coupled in series to increase the heating capacity.

2. The clean energy supply system according to claim 1, characterized in that: The air source heat pump water circulation system realizes three operation modes through the switching of the air source circulation pump and the automatic control valve; wherein, The air source heat pump water circulation system is connected in parallel with the water source heat pump unit and assists the water source heat pump unit in refrigeration; When the ambient temperature is greater than or equal to -5°C, the air source heat pump water circulation system independently generates heat; When the ambient temperature is lower than -5°C, the air source heat pump water circulation system and the water source heat pump unit are connected in series for heating.

3. The clean energy supply system according to claim 2, characterized in that: The coupling system of the air source heat pump unit and the water source heat pump unit is divided into four operating conditions throughout the year according to the ambient temperature, namely summer operating condition I, summer operating condition II, winter operating condition I and winter operating condition II; wherein, The summer operating condition I is a partial load in summer, and the water source heat pump unit operates in cooling mode alone; When the summer working condition II is the design daily load, the air source heat pump and the water source heat pump are connected in parallel for cooling; The winter operating condition I is when the ambient temperature is greater than or equal to -5°C, the air source heat pump alone generates heat; The winter working condition II is when the ambient temperature is less than -5°C, and the air source heat pump component and the water source heat pump component are connected in series to generate heat.

4. The clean energy supply system according to claim 3, characterized in that: The cooling tower water circulation system operates under summer operating conditions I and summer operating conditions II.

5. The clean energy supply system according to claim 4, characterized in that: The air conditioning water circulation system includes an air conditioning terminal and an air conditioning circulation pump; The automatic control valves include: valve K1, valve K2, valve K3 and valve K4; wherein, The valve K1 is used to control the water flow from the water source heat pump unit to the air conditioner terminal; The valve K2 is used to control the water flow from the air source heat pump unit to the air conditioner terminal; The valve K3 is used to control the water flow from the cooling tower unit to the condenser of the water source heat pump unit; The valve K4 is used to control the on / off of the series water path from the air source heat pump unit to the water source heat pump unit; In the summer operating condition I, the valve K1 and the valve K3 are opened, and the valve K2 and the valve K4 are closed; In the summer operating condition II, the valve K1 and the valve K3 are opened, and the valve K2 and the valve K4 are closed; In the winter operating condition I, the valve K2 and the valve K3 are opened, and the valve K1 and the valve K4 are closed; In the winter operating condition II, the valve K2 and the valve K4 are opened, and the valve K1 and the valve K3 are closed.

6. The clean energy supply system according to claim 4, characterized in that: In the winter operating condition I, the outlet water temperature of the air source heat pump unit is 44°C to 46°C; In the winter operating condition II, the outlet water temperature of the air source heat pump unit is 19°C to 21°C, and the outlet water temperature of the water source heat pump unit is 44°C to 46°C.

7. The clean energy supply system according to claim 4, characterized in that: In the winter operating condition II, in the series heating mode of the air source heat pump and the water source heat pump unit, the temperature difference between the outlet water temperature of the air source heat pump and the inlet water temperature of the water source heat pump unit does not exceed 25°C.

8. The clean energy supply system according to claim 7, characterized in that: The water source heat pump unit discharges condensation heat through the cooling tower circulation pump under summer working conditions I and summer working conditions II; The water source heat pump unit is used as a series heat source to improve heating efficiency under winter operating conditions I and winter operating conditions II.

9. The clean energy supply system according to claim 8, characterized in that: Under summer operating conditions I and summer operating conditions II, the cooling tower water circulation system transports the cooling water cooled by the cooling tower to the inlet of the condenser of the water source heat pump unit through the cooling tower circulation pump, and returns the condensation heat generated by the water source heat pump unit to the cooling tower through the outlet of the condenser, completing the cooling water system circulation volume of the water source heat pump unit.

10. The clean energy supply system according to claim 1, characterized in that: The selection of the air source heat pump unit is based on the minimum heating under the winter heating load and winter average temperature conditions.

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