Dual-frequency-conversion water mixing unit of air conditioner or air energy water system

Abstract

The invention provides a double-frequency-conversion water mixing unit of an air conditioner or an air energy water system. A double-frequency-conversion water mixing unit of an air conditioner or air energy water system comprises an inlet water temperature sensor, a return water temperature sensor, a tail end water mixing temperature sensor, a tail end return water temperature sensor, a water mixing pump, a circulating pump, a power line, a first one-way valve, a second one-way valve, a third one-way valve, a water inlet main pipe, a water mixing branch pipe, a tail end branch pipe and a double-frequency-conversion water mixing controller. The double-frequency-conversion water mixing controller is provided with a power line and two 485 communication lines and is connected with a water inlet temperature sensor, a return water temperature sensor, a tail end water mixing temperature sensor, a tail end return water temperature sensor, a water mixing pump and a circulating pump through wires. According to the double-frequency-conversion water mixing unit of the air conditioner or the air energy water system, the problems that a water mixing pump station in the prior art is inaccurate in temperature adjustment and low in reaction speed, indoor condensation is likely to be caused, and the requirement for popularization of a summer comfortable energy-saving refrigeration mode combining a wind disc and floor heating cannot be met are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners and air source heat pumps, and in particular to a dual-frequency water mixing unit for an air conditioner or air energy water system. Background Art

[0002] At present, the country is promoting energy conservation and emission reduction, improving the occupancy experience of real estate, and replacing coal with electricity in rural areas. Air conditioners and air source heat pump units have been widely used. Given the dual cooling and heating functions of the main unit, the existing installation method is usually to rely solely on air cooling and floor heating plus air disk heating.

[0003] With the development of intelligent control technology and frequency conversion technology, a more comfortable and energy-saving operating mode has emerged, that is, the combination of fan disk and floor heating for cooling in summer: the fan disk blows cold to achieve heat exchange and dehumidification, and the floor heating supercooled water is used for radiant cooling. The superposition of the two cooling methods can achieve the effect of less wind feeling and more comfortable temperature and humidity.

[0004] However, there is currently a lack of cost-effective accessories to support this mode of operation. In the past, mixing water pump stations were composed of proportional valves and water pumps, which had problems such as inaccurate temperature control and slow response speed, and easily caused indoor condensation. This has prevented the above-mentioned more comfortable and energy-saving mode of operation from being widely promoted.

[0005] Therefore, there is an urgent need for a water mixing unit that can improve water mixing efficiency and temperature accuracy and provide technical guarantees for radiant cooling. Summary of the Invention

[0006] In order to solve the above problems, the present invention provides a dual-frequency mixing water unit for air conditioning or air-to-water system to solve the problems of inaccurate temperature adjustment, slow response speed, easy to cause indoor condensation, and inability to meet the promotion of comfortable and energy-saving cooling methods in summer that combine air disks and floor heating.

[0007] According to a first aspect of the present invention, a dual-frequency conversion water mixing unit for an air-conditioning or air-to-water system is provided, wherein the dual-frequency conversion water mixing unit for the air-conditioning or air-to-water system is connected to refrigeration equipment and floor heating on both sides, and is characterized in that it includes: an inlet water temperature sensor, a return water temperature sensor, a terminal mixed water temperature sensor, a terminal return water temperature sensor, a mixing water pump, a circulation pump, a power cord, a two-way 485 communication line, a No. 1 check valve, a No. 2 check valve, a No. 3 check valve, a water inlet main pipe, a mixing water branch pipe, a terminal branch pipe, and a dual-frequency conversion water mixing controller;

[0008] The dual-frequency mixing water controller has a power line and two 485 communication lines, and is connected with the inlet water temperature sensor, return water temperature sensor, terminal mixing water temperature sensor, terminal return water temperature sensor, mixing water pump and circulation pump by wires;

[0009] One end of the water inlet main pipe and one end of the terminal branch pipe are respectively connected to the water outlet and water inlet interfaces of the refrigeration equipment;

[0010] The other end of the water inlet main pipe and the other end of the terminal branch pipe are respectively connected to the terminal water inlet interface and the terminal return interface of the floor heating;

[0011] The water inlet main is equipped with an inlet water temperature sensor, a mixing water pump, a No. 1 one-way valve and a terminal mixed water temperature sensor in sequence;

[0012] The mixed water branch pipe is equipped with a circulation pump and a No. 2 check valve in sequence;

[0013] The terminal branch pipe is equipped with a return water temperature sensor, a No. 3 one-way valve and a terminal return water temperature sensor in sequence;

[0014] One end of the mixed water branch pipe is connected to the water inlet main pipe, and one end of the mixed water branch pipe is located between the No. 1 check valve and the terminal mixed water temperature sensor;

[0015] The other end of the mixed water branch pipe is connected to the terminal branch pipe, and the other end of the mixed water branch pipe is located between the No. 3 one-way valve and the terminal return water temperature sensor.

[0016] Optionally, during summer cooling, the circulation pump is started first, and the water flow circulates only on the terminal side through the check effect of the No. 1 one-way valve and the No. 3 one-way valve.

[0017] Optionally, when the terminal needs medium or low temperature cold water, the mixing water pump is started, and the low temperature water on the refrigeration equipment side is transported by the mixing water pump to open the No. 1 one-way valve and enter the end of the water inlet main pipe and mix with the water in the mixing water branch pipe for temperature adjustment. The frequency of the mixing water pump is dynamically adjusted by the dual-frequency mixing water controller based on the user-set indoor temperature, humidity and the feedback value of the terminal mixing water temperature sensor to obtain the target temperature value after calculation;

[0018] When the temperature of the terminal mixed water temperature sensor is lower than the target temperature, the mixed water pump slows down;

[0019] When the temperature of the terminal mixed water temperature sensor is equal to the target temperature, the mixed water pump runs at a constant speed;

[0020] When the temperature of the terminal mixed water temperature sensor is higher than the target temperature, the mixed water pump accelerates.

[0021] Optionally, after the mixing water pump is started, the circulation pump switches to a constant temperature difference mode and adjusts the frequency according to the temperature difference between the terminal mixing water temperature sensor and the terminal return water temperature sensor;

[0022] When the temperature difference is greater than the set threshold, the circulation pump will run at a higher speed;

[0023] When the temperature difference is equal to the set threshold, the circulation pump runs at a constant speed;

[0024] When the temperature difference is less than the set threshold, the circulation pump runs at a reduced speed.

[0025] Optionally, both the mixing pump and the circulation pump adopt PID algorithm variable frequency control, with a response time of milliseconds, and support the following operating modes;

[0026] Real-time dew point tracking mode: Dynamically adjust the terminal mixed water temperature according to the indoor dew point temperature;

[0027] Constant terminal outlet water temperature mode: maintain the set value of the terminal mixed water temperature sensor;

[0028] Constant end return water temperature mode: maintains the set value of the end return water temperature sensor.

[0029] Beneficial effects:

[0030] 1. Precise water temperature regulation: Through the coordinated work of four temperature sensors and the dual-frequency mixing water controller, the mixed water temperature can be adjusted in real time and accurately according to the actual needs of the terminal, meeting the strict requirements of water temperature under different working conditions;

[0031] 2. High efficiency and energy saving: The intelligent variable frequency control of the mixing pump and the circulation pump, as well as the diversified operation modes, enable the system to automatically adjust the operating parameters according to the actual load and environmental conditions, effectively reducing energy consumption and improving energy utilization efficiency;

[0032] 3. Enhanced system stability: Reasonable water flow control design, such as the setting of the one-way valve and the constant temperature difference mode switching of the circulation pump, ensures the stability of the water flow under different working conditions, reduces water flow impact and fluctuation, and enhances the stability and reliability of the system;

[0033] 4. Strong adaptability: Supports multiple operating modes, especially the real-time dew point tracking mode, which enables the system to better adapt to different environmental conditions and provide a more comfortable indoor environment.

[0034] In summary, this application combines dual-pump frequency conversion technology to redesign the water circuit. The dual pumps have millisecond-level speed and temperature regulation capabilities, effectively improving water mixing efficiency and temperature accuracy. This provides technical support for radiant cooling, meeting the needs of comfortable and energy-saving summer cooling methods combined with fan coils and floor heating, and is conducive to the large-scale promotion of this operating mode. Therefore, this application solves the problem of existing mixing water pump stations with inaccurate temperature control, slow response speed, and easy indoor condensation, which cannot meet the needs of promoting comfortable and energy-saving summer cooling methods combined with fan coils and floor heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 The present invention provides a schematic structural diagram of a dual-frequency water mixing unit for an air-conditioning or air-to-water system.

[0036] List of reference numerals:

[0037] 1. Inlet water temperature sensor; 2. Return water temperature sensor; 3. Terminal mixed water temperature sensor; 4. Terminal return water temperature sensor; 5. Mixing water pump; 6. Circulation pump; 7. No. 1 check valve; 8. No. 2 check valve; 9. No. 3 check valve; 10. Inlet main pipe; 11. Mixing water branch pipe; 12. Terminal branch pipe; 13. Dual frequency mixing water controller. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0039] In the description of the present invention, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0040] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0041] Reference Figure 1 The present invention provides a dual-frequency mixing water unit for air conditioning or air-to-water systems, which can solve the problems of inaccurate temperature control, slow response speed, and easy indoor condensation in the mixing water pump station, and cannot meet the promotion of comfortable and energy-saving cooling methods in summer that combine air disks and floor heating.

[0042] The present invention provides a dual-frequency conversion water mixing unit for an air conditioning or air-to-water system, wherein the dual-frequency conversion water mixing unit for the air conditioning or air-to-water system is connected to refrigeration equipment and floor heating on both sides, and is characterized by comprising: an inlet water temperature sensor 1, a return water temperature sensor 2, a terminal mixed water temperature sensor 3, a terminal return water temperature sensor 4, a mixing water pump 5, a circulating pump 6, a power cord, a two-way 485 communication line, a No. 1 check valve 7, a No. 2 check valve 8, a No. 3 check valve 9, a water inlet main pipe 10, a mixing water branch pipe 11, a terminal branch pipe 12, and a dual-frequency conversion water mixing controller 13;

[0043] The dual-frequency mixing water controller 13 has a power line and two 485 communication lines, and is connected with the inlet water temperature sensor 1, the return water temperature sensor 2, the terminal mixing water temperature sensor 3, the terminal return water temperature sensor 4, the mixing water pump 5 and the circulation pump 6 by wires;

[0044] One end of the water inlet main pipe 10 and one end of the terminal branch pipe 12 are respectively connected to the water outlet and water inlet of the refrigeration equipment;

[0045] The other end of the water inlet main pipe 10 and the other end of the terminal branch pipe 12 are respectively connected to the terminal water inlet interface and the terminal return interface of the floor heating;

[0046] The water inlet main pipe 10 is provided with an inlet water temperature sensor 1, a mixing water pump 5, a No. 1 one-way valve 7 and a terminal mixed water temperature sensor 3 in sequence;

[0047] The mixed water branch pipe 11 is provided with a circulation pump 6 and a second check valve 8 in sequence;

[0048] The terminal branch pipe 12 is provided with a return water temperature sensor 2, a No. 3 one-way valve 9 and a terminal return water temperature sensor 4 in sequence;

[0049] One end of the mixed water branch pipe 11 is connected to the water inlet main pipe 10, and one end of the mixed water branch pipe 11 is located between the first one-way valve 7 and the terminal mixed water temperature sensor 3;

[0050] The other end of the mixed water branch pipe 11 is connected to the terminal branch pipe 12 , and the other end of the mixed water branch pipe 11 is located between the No. 3 one-way valve 9 and the terminal return water temperature sensor 4 .

[0051] Among them, by integrating the inlet water temperature sensor 1, the return water temperature sensor 2, the terminal mixed water temperature sensor 3, the terminal return water temperature sensor 4, the mixing water pump 5, the circulation pump 6, the power cord, the 2-way 485 communication line, the No. 1 one-way valve 7, the No. 2 one-way valve 8, the No. 3 one-way valve 9, the water inlet main pipe 10, the mixing water branch pipe 11, the terminal branch pipe 12 and the dual-frequency mixing water controller 13 into one unit, the mixing water unit has a small volume and high integration after integration, can be built into the air conditioner or air energy as an accessory, and can also be installed in the indoor closet or on the ceiling, taking up little space and being easy to install.

[0052] Optionally, a flow sensor and a humidity sensor are further included, and the dual-frequency mixing water controller 13 is connected to the flow sensor and the temperature sensor respectively.

[0053] Among them, the flow sensor can be installed on the water inlet pipe to count the flow, and then combined with the value of the inlet and return water temperature sensor 2 to calculate the real-time thermal energy and accumulated thermal energy, providing data support for the energy-saving operation of the system;

[0054] The humidity sensor can collect humidity values ​​and calculate the dew point temperature in combination with the indoor temperature sensor.

[0055] 2-way 485 communication, one is used to collect indoor temperature and humidity to calculate the real-time dew point value, and the other can be connected to the smart home system to realize the whole house intelligence.

[0056] Reference Figure 1 Optionally, during summer cooling, the circulation pump 6 is started first, and the water flow circulates only at the end side through the check effect of the No. 1 one-way valve 7 and the No. 3 one-way valve 9.

[0057] Among them, when the circulation pump 6 is started, the water flows on the check side of the No. 1 one-way valve and the No. 3 one-way valve. The water flow cannot open the two one-way valves and can only flow in the terminal pipeline to form a circulation.

[0058] Reference Figure 1 Optionally, when the terminal needs medium or low temperature cold water, the mixing water pump 5 is started, and the low temperature water on the refrigeration equipment side is transported by the mixing water pump 5 to open the No. 1 one-way valve 7 and enter the end side of the water inlet main pipe 10 and mix with the water in the mixing water branch pipe 11 to adjust the temperature. The frequency of the mixing water pump 5 is dynamically adjusted by the dual-frequency mixing water controller 13 according to the user-set indoor temperature, humidity and the feedback value of the terminal mixed water temperature sensor 3 after calculating the target temperature value;

[0059] When the temperature of the terminal mixed water temperature sensor 3 is lower than the target temperature, the mixed water pump 5 slows down;

[0060] When the temperature of the terminal mixed water temperature sensor 3 is equal to the target temperature, the mixed water pump 5 runs at a constant speed;

[0061] When the temperature of the terminal mixed water temperature sensor 3 is higher than the target temperature, the mixed water pump 5 is accelerated.

[0062] Among them, under the refrigeration condition, the water temperature after the unit is refrigerated will be lower than the dew point temperature. Directly supplying water to the indoor floor heating pipe will cause condensation indoors. At this time, the water after the refrigeration equipment is refrigerated and the circulating water in the indoor floor heating pipe needs to be mixed at a suitable temperature above the dew point to provide cooling for the room. The process of mixed temperature control is the process of controlling how much cold water the mixing water pump 5 delivers. If too much cold water is delivered, the mixed water temperature will be lower than the dew point temperature; if too little cold water is delivered, the water temperature cannot meet the indoor cooling requirements. At this time, it is necessary to adjust the speed of the pump 5 in real time through the PID algorithm based on the value of the temperature sensor 3 to achieve the purpose of real-time temperature control.

[0063] Reference Figure 1 , Optionally, after the mixing water pump 5 is started, the circulation pump 6 switches to the constant temperature difference mode and adjusts the frequency according to the temperature difference between the terminal mixing water temperature sensor 3 and the terminal return water temperature sensor 4;

[0064] When the temperature difference is greater than the set threshold, the circulation pump 6 increases its speed;

[0065] When the temperature difference is equal to the set threshold, the circulation pump 6 runs at a constant speed;

[0066] When the temperature difference is less than the set threshold, the circulation pump 6 runs at a reduced speed.

[0067] Among them, the operation of the supply water and return water at a constant temperature difference of 5°C is the national standard for the development of air-conditioning water system equipment. The equipment has the highest energy efficiency when operating at a temperature difference of 5°C, so the circulation pump 6 must achieve the effect of a constant temperature difference of 5°C at an operating frequency. When the water pump speed is too high, the flow rate increases, and the water cannot completely exchange heat in the system and is circulated away, wasting energy. When the water pump speed is too low, the flow rate decreases, and the water cannot exchange heat in the system enough, and the operating effect cannot be achieved.

[0068] Therefore, based on the thermal energy formula: Q = CM (T1-T2);

[0069] Q stands for calories;

[0070] C represents the specific heat capacity of the medium;

[0071] M represents the mass of the medium;

[0072] T1-T2 represents the temperature difference;

[0073] When the flow rate is too large, the temperature difference becomes smaller and the Q value becomes smaller. Although the M value becomes larger, the curve of the Q value obtained by this formula is a parabola. Only when the M value and the T1-T2 value are at a certain point, the Q value is the largest. The research and development of HVAC equipment follows the national standard of 5℃, that is, when T1-T2=5, the equipment has the highest energy efficiency. The factors affecting the Q value C are fixed values, and T1-T2=5 are fixed values. When the Q value is the largest, the temperature difference of 5℃ corresponding to the M value is the only value. If the water flows too fast, the temperature difference of 5 degrees will become smaller. If the water flows too slowly, the temperature difference will become larger, which will make the Q value smaller. Therefore, the circulation pump must be operated in accordance with the national standard constant temperature difference to achieve the most energy-saving system.

[0074] Reference Figure 1 , Optionally, both the mixing water pump 5 and the circulation pump 6 adopt PID algorithm variable frequency control, with a response time of milliseconds, and support the following operating modes;

[0075] Real-time dew point tracking mode: Dynamically adjust the terminal mixed water temperature according to the indoor dew point temperature;

[0076] Constant terminal outlet water temperature mode: maintains the set value of the terminal mixed water temperature sensor 3;

[0077] Constant terminal return water temperature mode: maintains the set value of the terminal return water temperature sensor 4.

[0078] Among them, the constant temperature difference circulation control in the HVAC system (such as the air conditioning water system and the floor heating system) adopts the PID algorithm. The core goal is to maintain the temperature difference between the supply and return water pipes (ΔT = T_supply-T_reture) constant at the set value (ΔT_set). This can optimize the system energy efficiency, ensure the heat exchange efficiency and protect the equipment. The HVAC constant temperature difference PID needs to focus on solving the three major problems of large thermal inertia, significant hysteresis, and noise interference. Through cascade control, filtering algorithm, integral limiting and other optimizations, the ability to stably achieve millisecond-level frequency conversion is achieved. The above algorithm is existing technology and will not be elaborated on here. It is based on the ability to implement this solution.

[0079] Example:

[0080] Summer cooling operation:

[0081] When entering the summer cooling mode, the dual-frequency mixing unit is started, and the circulation pump 6 starts working first. Under the action of the No. 1 one-way valve 7 and the No. 3 one-way valve 9, the water circulates only on the end side. At this time, the return water on the end side passes through the circulation pump 6 and returns to the end through the mixing branch pipe 11, maintaining the water temperature on the end side relatively stable.

[0082] When the end user needs medium or low temperature cold water, the dual-frequency mixing water controller 13 receives the user-set temperature signal and the feedback signal of the end mixed water temperature sensor 3. If the end mixed water temperature is higher than the target temperature, the dual-frequency mixing water controller 13 issues an instruction to increase the frequency of the mixing water pump 5, so that more low-temperature water from the refrigeration equipment is mixed with the end return water, thereby reducing the mixed water temperature; if the end mixed water is stably lower than the target temperature, the frequency of the mixing water pump 5 is reduced to reduce the amount of low-temperature water mixed in. When the temperature reaches the target value, the mixing water pump 5 runs at a constant speed.

[0083] At the same time, after the mixing water pump 5 is started, the circulating pump 6 switches to the constant temperature difference mode. The circulating pump 6 adjusts its own frequency according to the temperature difference between the terminal mixed water temperature sensor 3 and the terminal return water temperature sensor 4. If the temperature difference is greater than the set threshold, it means that the terminal heat load is large, and the circulating pump 6 speeds up to accelerate the water circulation and enhance the heat dissipation effect; if the temperature difference is equal to the set threshold, the circulating pump 6 runs at a constant speed. If the temperature difference is less than the set threshold, the circulating pump 6 slows down to reduce energy consumption.

[0084] Switch between different operating modes:

[0085] Real-time dew point tracking mode: The dual-frequency mixing water controller 13 obtains indoor dew point temperature data and related temperature and humidity data in real time, and dynamically adjusts the terminal mixing water temperature according to the change of dew point temperature. For example, when the indoor dew point temperature rises, the terminal mixing water temperature is appropriately increased to prevent condensation indoors; when the indoor dew point temperature drops, the terminal mixing water temperature is correspondingly lowered to ensure indoor comfort and increase indoor cooling speed.

[0086] Constant terminal outlet water temperature mode: The user sets the target value of the terminal mixed water temperature sensor 3 on the dual-frequency mixing water controller 13. The dual-frequency mixing water controller 13 continuously monitors the feedback value of the terminal mixed water temperature sensor 3 and adjusts the operating parameters of the circulation pump 6 and the mixing water pump 5 to keep the terminal mixed water temperature at the set value at all times without being disturbed by other factors, thereby providing stable water supply for the terminal equipment.

[0087] Constant terminal return water mode: the target value of the terminal return water temperature sensor 4 is set in the dual-frequency mixing water controller 13. The dual-frequency mixing water controller 13 adjusts the operating parameters of the circulation pump 6 and the mixing water pump 5 according to the feedback signal of the terminal return water temperature sensor 4. When the terminal return water temperature is higher than the set value, the frequency of the mixing water pump 5 is increased to introduce more low-temperature water. At the same time, the frequency of the circulation pump 6 is appropriately adjusted to speed up the water circulation and reduce the return water temperature; when the return water temperature is lower than the set value, the frequency of the mixing water pump 5 is reduced to reduce the inflow of low-temperature water. At the same time, the frequency of the circulation pump 6 is appropriately adjusted to slow down the water circulation and increase the return water temperature to ensure that the terminal return water temperature is stable at the set value.

[0088] Through the above detailed embodiments, the dual-frequency mixing unit of this air-conditioning or air-to-water system can operate efficiently and intelligently, achieve precise water temperature regulation, energy saving and consumption reduction, and good system stability and adaptability, providing strong support for the optimized operation of the HVAC system.

[0089] It should be noted that not all steps and modules in the above processes and system structure diagrams are required, and certain steps or modules can be omitted according to actual needs. The execution order of each step is not fixed and can be adjusted as needed. The system structure described in the above embodiments can be a physical structure or a logical structure, that is, some modules may be implemented by the same physical entity, or some modules may be implemented by multiple physical entities, or may be implemented by certain components in multiple independent devices.

[0090] In each of the above embodiments, the hardware module can be implemented mechanically or electrically. The present invention is shown and described in detail above through the accompanying drawings and preferred embodiments. However, the present invention is not limited to these disclosed embodiments. Based on the above multiple embodiments, those skilled in the art will know that the code review methods in the above different embodiments can be combined to obtain more embodiments of the present invention, and these embodiments are also within the scope of protection of the present invention.

Claims

1. A dual-frequency water mixing unit for an air conditioning or air-to-water system, wherein both sides of the dual-frequency water mixing unit are connected to a refrigeration device and a floor heating device, characterized in that: include: Inlet water temperature sensor (1), return water temperature sensor (2), terminal mixed water temperature sensor (3), terminal return water temperature sensor (4), mixing water pump (5), circulation pump (6), power cord, two-way 485 communication line, No. 1 check valve (7), No. 2 check valve (8), No. 3 check valve (9), water inlet main pipe (10), mixing water branch pipe (11), terminal branch pipe (12) and dual-frequency mixing water controller (13); The dual-frequency mixing water controller (13) has the power line and the two-way 485 communication lines, and is connected to the inlet water temperature sensor (1), the return water temperature sensor (2), the terminal mixing water temperature sensor (3), the terminal return water temperature sensor (4), the mixing water pump (5) and the circulation pump (6) by wires; One end of the water inlet main pipe (10) and one end of the terminal branch pipe (12) are respectively connected to the water outlet and water inlet of the refrigeration equipment; The other end of the water inlet main pipe (10) and the other end of the terminal branch pipe (12) are respectively connected to the terminal water inlet connection and the terminal return connection of the floor heating; The water inlet main pipe (10) is provided with the water inlet temperature sensor (1), the water mixing pump (5), the first one-way valve (7) and the terminal mixed water temperature sensor (3) in sequence; The circulating pump (6) and the second one-way valve (8) are sequentially provided on the water mixing branch pipe (11); The terminal branch pipe (12) is provided with the return water temperature sensor (2), the No. 3 one-way valve (9) and the terminal return water temperature sensor (4) in sequence; One end of the water mixing branch pipe (11) is connected to the water inlet main pipe (10), and one end of the water mixing branch pipe (11) is located between the first one-way valve (7) and the terminal mixed water temperature sensor (3); The other end of the water mixing branch pipe (11) is connected to the terminal branch pipe (12), and the other end of the water mixing branch pipe (11) is located between the No. 3 one-way valve (9) and the terminal return water temperature sensor (4).

2. A dual-frequency water mixing unit for an air-conditioning or air-to-water system according to claim 1, characterized in that: During summer cooling, the circulation pump (6) is first started, and the water flow circulates only at the terminal side through the check function of the No. 1 one-way valve (7) and the No. 3 one-way valve (9).

3. A dual-frequency water mixing unit for an air-conditioning or air-to-water system according to claim 2, characterized in that: When the terminal needs medium or low temperature cold water, the mixing water pump (5) is started, and the low temperature water on the refrigeration equipment side is transported by the mixing water pump (5) to open the No. 1 one-way valve (7) and enter the end side of the water inlet main pipe (10) and is mixed with the water in the mixing water branch pipe (11) to adjust the temperature. The frequency of the mixing water pump (5) is dynamically adjusted by the dual-frequency mixing water controller (13) according to the user-set indoor temperature and humidity and the feedback value of the terminal mixing water temperature sensor (3) after calculating the target temperature value; When the temperature of the terminal mixed water temperature sensor (3) is lower than the target temperature, the mixed water pump (5) is decelerated; When the temperature of the terminal mixed water temperature sensor (3) is equal to the target temperature, the mixed water pump (5) operates at a constant speed; When the temperature of the terminal mixed water temperature sensor (3) is higher than the target temperature, the mixed water pump (5) is accelerated.

4. A dual-frequency water mixing unit for an air-conditioning or air-to-water system according to claim 3, characterized in that: After the mixing water pump (5) is started, the circulation pump (6) switches to a constant temperature difference mode and adjusts the frequency according to the temperature difference between the terminal mixing water temperature sensor (3) and the terminal return water temperature sensor (4); When the temperature difference is greater than a set threshold, the circulating pump (6) is accelerated; When the temperature difference is equal to a set threshold, the circulating pump (6) runs at a constant speed; When the temperature difference is less than a set threshold, the circulation pump (6) runs at a reduced speed.

5. A dual-frequency water mixing unit for an air-conditioning or air-to-water system according to claim 4, characterized in that: The water mixing pump (5) and the circulation pump (6) both adopt PID algorithm frequency conversion control, with a response time of milliseconds, and support the following operating modes; Real-time dew point tracking mode: Dynamically adjust the terminal mixed water temperature according to the indoor dew point temperature; Constant terminal outlet water temperature mode: maintaining the set value of the terminal mixed water temperature sensor (3); Constant terminal return water temperature mode: maintains the set value of the terminal return water temperature sensor (4) for operation.

Images