Fan coil unit adopting double-working-condition coil and control method of fan coil unit

Abstract

The invention discloses a fan coil unit adopting a double-working-condition coil and a control method of the fan coil unit, and relates to the technical field of air conditioning, and the fan coil unit comprises the double-working-condition coil, a fan, a water condensing disc and a box body. The double-working-condition coil pipe is composed of a double-partition coil pipe and a valve assembly, the double-partition coil pipe is provided with a first heat exchange area and a second heat exchange area, and air conditioner cold and hot water flowing through the first heat exchange area of the double-partition coil pipe can completely, partially or not flow through the second heat exchange area of the double-partition coil pipe through adjustment of the valve assembly. The first heat exchange area of the double-partition coil pipe operates under the wet working condition, and the second heat exchange area operates under the dry working condition during cooling. After the fan runs, indoor return air enters the box body through a return air inlet formed in the box body, is cooled or heated by the first heat exchange area and the second heat exchange area of the double-partition coil pipe and then is sent out through an air supply outlet formed in the box body. The air supply temperature and humidity are adjusted, air supply dewing is prevented, low-temperature cold water can be adopted for cooling, and the energy consumption of an air conditioner water transmission and distribution system is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a fan coil unit adopting a dual-mode coil and a control method thereof. Background Art

[0002] As a terminal device for air conditioning, a fan coil unit primarily consists of a speed-controlled fan, coils, and a condensate pan. Due to its compact structure, flexible layout, and ease of independent control, it is widely used in residences, offices, hotels, hospitals, and other places. Fan coil units do not have their own heat or cold source. Instead, hot and cold water produced by a chiller, heat pump, boiler, or other heat or cold source is delivered to the fan coil unit through a distribution system. The fan continuously recirculates the indoor air through the coils. As the indoor air passes through the coils, it absorbs the cooling / heating energy of the cooling / hot water flowing through the coils through forced convection heat exchange with the fin surfaces, cooling / heating the indoor environment and maintaining a constant indoor temperature.

[0003] Fan coil units often use local control solutions, which are divided into simple control and temperature control. Simple control uses a three-speed switch to manually control the fan's three speeds and start and stop. Temperature control uses a thermostat to automatically control the opening and closing / opening degree of the solenoid valve / electric two-way control valve and the fan's three speeds based on the comparison and calculation between the set indoor temperature and the actual indoor temperature. Alternatively, it directly controls the fan's three speeds and start and stop. This achieves a constant indoor temperature by controlling the cold / hot water supply, flow rate, and air volume. Existing fan coil unit control methods cannot simultaneously adjust the unit's supply air temperature and humidity.

[0004] As low-temperature chiller technology becomes more and more mature and ice storage systems become more popular, more and more air-conditioning projects will adopt low-temperature chilled water systems to achieve energy conservation. When fan coil units can use low-temperature chilled water for water supply, the lower the cold water supply temperature, the greater the temperature difference between the cold water supply and return water, and the more cooling capacity can be exchanged per unit water volume. For the same indoor heat load, the required cold water flow rate will be smaller, the energy consumption of the distribution system will be smaller, the operating costs will be greatly reduced, and the distribution pipelines can be designed according to smaller specifications, thereby reducing the investment cost of the distribution system.

[0005] Currently, fan coil units are set at chilled water supply and return temperatures of 7.0°C / 12.0°C. Actual performance measurements of fan coil units show that, under conditions of constant air volume and supply water temperature, changes in chilled water supply have a relatively slow effect on cooling capacity. Given a constant chilled water supply and return water temperature differential, a 1°C increase in supply water temperature reduces cooling capacity by approximately 10%. Higher supply water temperatures increase cooling capacity and reduce dehumidification capacity. When the chilled water supply temperature falls below 7°C, the fan coil unit's supply air temperature is too low, leading to indoor dew when indoor humidity is high. When the chilled water supply temperature falls below 5°C, condensation can occur in the fan coil unit. Summary of the Invention

[0006] The present invention addresses the problems in the prior art that when a fan coil unit adopts low-temperature cold water supply, the supply air temperature is too low, resulting in indoor condensation and condensation of the fan coil unit itself, and the fan coil unit supply air temperature and humidity cannot be automatically adjusted at the same time. The present invention provides a fan coil unit using a dual-mode coil and a control method thereof.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A fan coil unit using a dual-mode coil comprises the dual-mode coil, a fan, a condensate pan, and a housing. The housing is provided with a return air vent and a supply air vent. The fan and dual-mode coil are housed within the housing, with the bottom of the dual-mode coil placed in the condensate pan. The dual-mode coil comprises a dual-zone coil and a valve assembly. The dual-zone coil has a first heat exchange zone and a second heat exchange zone, which are connected by a valve assembly. Adjustment of the valve assembly allows the air conditioning hot and cold water flowing through the first heat exchange zone of the dual-zone coil to flow entirely, partially, or not at all through the second heat exchange zone. To provide cooling, the first heat exchange zone of the dual-zone coil operates in a wet condition, while the second heat exchange zone operates in a dry condition. After the fan is running, the indoor return air enters the box through the return air inlet provided on the box, is cooled or heated by the first heat exchange zone and the second heat exchange zone of the dual-zone coil, and is then sent out through the air supply outlet provided on the box. During cooling, the condensed water generated by the dual-mode coil flows into the condensate tray and is discharged through the condensate interface.

[0009] Based on the above technical solution, further, the double-zone coil includes a water supply joint, a water outlet joint, a water collecting pipe, a water distribution pipe, a water collection pipe, a heat exchange tube, a U-shaped tube, and a fin; wherein the water supply joint, the water collection pipe, multiple rows of U-shaped coils arranged between the water supply joint and the water collection pipe, and multiple fins arranged in parallel at approximately equal distances constitute the first heat exchange zone, which is located at the lower part of the double-zone coil. The U-shaped coil in the first heat exchange zone is formed by multiple heat exchange tubes and multiple U-shaped tubes connected end to end in sequence. One end of the U-shaped coil is connected to the water supply joint, and the other end of the U-shaped coil is connected to the water collection pipe; the water distribution pipe, the water collection pipe, the heat exchange tube, the U-shaped tube, and the fin are connected. The second heat exchange zone is composed of multiple rows of U-shaped coils and multiple fins arranged in parallel at approximately equal distances between the water distribution pipe and the water collection pipe. The U-shaped coil in the second heat exchange zone is also composed of multiple heat exchange tubes and multiple U-shaped tubes connected end to end in sequence. One end of the U-shaped coil is connected to the water distribution pipe, and the other end of the U-shaped coil is connected to the water collection pipe. The multiple fins in the first heat exchange zone and the second heat exchange zone of the double-partition coil are connected in sequence to form a fluid channel for airflow. The cold water flowing in the heat exchange tubes cools the air flowing between the fins, and the hot water flowing in the heat exchange tubes heats the air flowing between the fins.

[0010] Based on the above technical solution, further, the water collecting pipe is provided with a first water outlet interface, the water branch pipe is provided with a second water inlet interface, the water collecting pipe is provided with a second water outlet interface and a water collecting interface, and the second water outlet interface is connected to the water outlet joint; the air-conditioning cold and hot water flows evenly into each U-shaped coil in the first heat exchange area through the opening on the water inlet joint, and the air-conditioning cold and hot water flowing through each U-shaped coil is collected into the water collecting pipe through the opening on the water collecting pipe, and flows out from the first water outlet interface on the water collecting pipe; the air-conditioning cold and hot water flows from the second water inlet interface into the water branch pipe, and flows evenly into each U-shaped coil in the second heat exchange area through the opening of the water branch pipe, and the air-conditioning cold and hot water flowing through each U-shaped coil flows to the water collecting pipe through the opening on the water collecting pipe, and flows out from the water outlet joint connected to the water collecting pipe.

[0011] Based on the above technical solution, further, the dual-zone coil is further provided with a left guard plate and a right guard plate; the left guard plate and the right guard plate are formed by bending and are provided on the periphery of the fin.

[0012] Based on the above technical solution, further, the water collecting pipe, water distribution pipe, water collecting pipe, heat exchange tube, and U-shaped tube are all made of copper tubes, and the fins are made of aluminum fins; a plurality of tube holes of the same size are evenly opened on the fins, and the fins are installed on the heat exchange tubes through the tube holes. The fins are expanded with the heat exchange tubes through a tube expander to realize heat conduction and heat exchange with the heat exchange tubes.

[0013] Based on the above technical solution, further, the dual-zone coil can adopt one of two rows of tubes, three rows of tubes, and four rows of tubes, and the area ratio of the first heat exchange zone to the second heat exchange zone is between 2:1 and 5:1.

[0014] Based on the above technical solution, the valve assembly includes a first regulating valve and one, two, or all of the first, second, and third connecting pipes. The first regulating valve is an electric three-way regulating valve. The water collection pipe of the first heat exchange zone of the dual-zone coil is connected to the water distribution pipe of the second heat exchange zone via the valve assembly. Simultaneously, the water collection pipe of the first heat exchange zone is connected to the water collection pipe of the second heat exchange zone via the valve assembly. The specific connection method is that one end of the first connecting pipe of the valve assembly is connected to the first water outlet interface on the water collecting pipe, and the other end of the first connecting pipe is connected to the inlet of the DC branch of the first regulating valve, or the inlet of the DC branch of the first regulating valve of the valve assembly is directly connected to the first water outlet interface on the water collecting pipe; one end of the second connecting pipe of the valve assembly is connected to the outlet of the DC branch of the first regulating valve, and the other end of the second connecting pipe is connected to the second water inlet interface on the water distribution pipe, or the outlet of the DC branch of the first regulating valve of the valve assembly is directly connected to the second water inlet interface on the water distribution pipe; one end of the third connecting pipe of the valve assembly is connected to the bypass branch of the first regulating valve, and the other end of the third connecting pipe is connected to the water collection interface on the water collecting pipe, or the bypass branch of the first regulating valve of the valve assembly is directly connected to the water collection interface on the water collecting pipe.

[0015] Based on the above technical solution, further, the fan adopts a cross-flow fan, the fan motor can adopt a DC brushless motor, and can adopt 48V DC power supply.

[0016] Based on the above technical solution, further, when the unit is installed horizontally, the air supply port is located at the front end of the box, and the return air port is located at the rear end or lower rear part of the box; when the gas delivery form adopts a pressure delivery type, the fan is located behind the dual-mode coil, and when the gas delivery form adopts a suction type, the fan is located in front of the dual-mode coil.

[0017] Based on the above technical solution, further, when the unit is installed vertically, the supply air outlet is located at the top of the box and the return air outlet is located at the bottom of the box; when the gas delivery form adopts the pressure delivery type, the fan is located below the dual-mode coil, and when the gas delivery form adopts the suction type, the fan is located above the dual-mode coil.

[0018] Based on the above technical solution, a controller, a control panel, a first temperature sensor, a second temperature sensor, and a second regulating valve are further provided. The first temperature sensor is located at the air outlet of the first heat exchange zone of the dual-mode coil and is used to collect the dry-bulb temperature of the air outlet from the first heat exchange zone of the dual-mode coil. The second temperature sensor is located in the air supply port of the cabinet and is used to collect the dry-bulb temperature of the air supply from the unit. The second regulating valve is an electric two-way regulating valve and is used to adjust the flow rate of the air-conditioning hot and cold water flowing through the first heat exchange zone of the dual-mode coil.

[0019] Based on the above technical solution, further, a computing module and an information processing module are provided inside the controller, and the connection mode between the computing module and the information processing module is a communication connection. The controller and the control panel are connected through a stepless point communication interface of a twisted pair. The controller is provided with multiple I / O interfaces, which are used to connect to the control panel, the first temperature sensor, the second temperature sensor, the first regulating valve, the second regulating valve and the fan respectively; the control panel is provided with a display screen and operation buttons, and a temperature sensor and a humidity sensor are provided in the control panel for collecting the indoor temperature and the indoor relative humidity, and displaying the indoor temperature and the indoor relative humidity at the same time. The indoor temperature and the indoor relative humidity can be set through the control panel.

[0020] Based on the above technical solution, further, the controller controls the opening and closing states of the DC branch and the bypass branch of the first regulating valve according to the set operating mode of the on-site control panel, thereby realizing conversion between different operating modes; the controller is equipped with an information processing module, and according to the set indoor temperature and indoor relative humidity, the information processing module in the controller automatically compares the measured values and set values of the indoor temperature and relative humidity, and automatically controls the opening of the DC branch and the bypass branch of the first regulating valve, the opening of the second regulating valve, and the speed of the fan, and sequentially adjusts the air conditioning hot and cold water flow and the fan air volume flowing through the first heat exchange zone and the second heat exchange zone of the dual-mode coil, thereby achieving the purpose of regulating the indoor temperature and humidity.

[0021] Based on the above technical solution, further, the present invention provides a control method for a fan coil unit using a dual-mode coil, which is applied to a fan coil unit using a dual-mode coil. The control method includes a temperature and humidity dual-control cooling operation mode, a low-temperature cold water cooling and anti-condensation operation mode, a normal temperature cold water cooling operation mode, a heating operation mode, and a duty heating operation mode. The specific operation modes are described as follows:

[0022] 1) When the air conditioning cold water uses low-temperature cold water below 7°C and normal temperature cold water above 7°C, and there is a humidity control requirement, the temperature and humidity dual control cooling operation mode can be adopted, including the following steps:

[0023] Step S1: Use the temperature sensor and humidity sensor in the control panel to collect the indoor temperature and indoor relative humidity; use the first temperature sensor to collect the outlet dry bulb temperature of the first heat exchange zone of the dual-mode coil; use the second temperature sensor to collect the supply air dry bulb temperature; set the temperature and humidity dual-control cooling operation mode, indoor temperature and indoor relative humidity on the control panel.

[0024] Step S2: Based on the set indoor temperature and indoor relative humidity, the calculation module in the controller calculates the dew point temperature and wet bulb temperature according to the enthalpy-humidity diagram; the information processing module in the controller receives the dew point temperature and wet bulb temperature input by the calculation module, sets the preset temperature of the first temperature sensor and the preset temperature of the second temperature sensor, and further, the preset temperature of the first temperature sensor is 2°C lower than the calculated wet bulb temperature, and the preset temperature of the second temperature sensor is 2°C higher than the calculated dew point temperature.

[0025] Step S3: The information processing module in the controller partially opens the DC branch of the first regulating valve and opens the bypass branch in inverse proportion, and the second regulating valve is in the preset open state; the fan is running, and the indoor return air enters the box through the return air inlet provided on the box body, is cooled by the first heat exchange zone and the second heat exchange zone of the dual-mode coil, and is then sent out through the air supply outlet provided on the box body.

[0026] Step S4: The information processing module in the controller automatically compares the actual measured value of the first temperature sensor with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve, reduces or increases the air-conditioning cold water flow through the second heat exchange zone of the dual-zone coil, until the actual measured value of the first temperature sensor reaches the preset temperature; at the same time, the information processing module of the controller automatically compares the actual measured value of the indoor temperature with the set value, and the information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the air-conditioning cold water flow through the first heat exchange zone of the dual-mode coil and / or adjusts the air volume of the fan until the indoor temperature and relative humidity reach the set value, and makes the supply air temperature higher than the indoor dew point temperature by 2°C to ensure that the supply air does not condense.

[0027] 2) When the air conditioning cold water uses low-temperature cold water with a temperature below 7°C and there is no humidity control requirement, the low-temperature cold water cooling and anti-condensation operation mode can be adopted, including the following steps:

[0028] Step A1: Use the temperature sensor and humidity sensor in the control panel to collect the indoor temperature and indoor relative humidity; use the first temperature sensor to collect the outlet dry-bulb temperature of the first heat exchange zone of the dual-mode coil; use the second temperature sensor to collect the supply air dry-bulb temperature; set the low-temperature chilled water cooling and anti-condensation operation mode and indoor temperature on the control panel, and the system default value of the indoor relative humidity is 60%.

[0029] Step A2: Based on the set indoor temperature and the system default value of the indoor relative humidity of 60%, the calculation module in the controller calculates the indoor dew point temperature and the indoor wet-bulb temperature according to the enthalpy-humidity diagram; the information processing module in the controller receives the indoor dew point temperature and the indoor wet-bulb temperature input by the calculation module, sets the preset temperature of the first temperature sensor and the preset temperature of the second temperature sensor, further, the preset temperature of the first temperature sensor is 2°C lower than the calculated indoor wet-bulb temperature, and the preset temperature of the second temperature sensor is 2°C higher than the calculated indoor dew point temperature.

[0030] Step A3: The information processing module in the controller partially opens the DC branch of the first regulating valve and opens the bypass branch in inverse proportion, and the second regulating valve is in the preset open state; the fan is running, and the indoor return air enters the box through the return air inlet provided on the box body, is cooled by the first heat exchange zone and the second heat exchange zone of the dual-zone coil, and is then delivered out through the supply air outlet provided on the box body.

[0031] Step A4: The information processing module in the controller automatically compares the actual measured value of the first temperature sensor with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve, and reduces or increases the air-conditioning cold water flow through the second heat exchange zone of the dual-mode coil until the actual measured value of the first temperature sensor reaches the preset temperature; at the same time, the information processing module in the controller automatically compares the actual measured value of the indoor temperature with the set value, and the information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the air-conditioning cold water flow through the first heat exchange zone of the dual-mode coil and / or adjusts the air volume of the fan until the indoor temperature reaches the set value, the indoor relative humidity reaches the system default value of 60%, and the supply air temperature is set to 2°C higher than the indoor dew point temperature to ensure that the supply air does not condense.

[0032] 3) When the air conditioning cold water uses a temperature higher than 7°C and there is no humidity control requirement, the normal temperature cold water cooling operation mode can be adopted, including the following steps:

[0033] Step B1: Use the temperature sensor in the control panel to collect the indoor temperature; set the normal temperature cold water cooling operation mode and the indoor temperature on the control panel.

[0034] Step B2: The information processing module in the controller adjusts the first regulating valve to a preset state in which the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in an open state; the fan is running, and the indoor return air enters the box through the return air inlet provided on the box body, is cooled by the first heat exchange zone and the second heat exchange zone of the dual-zone coil, and is then delivered out through the supply air outlet provided on the box body.

[0035] Step B3: The information processing module in the controller automatically compares the measured indoor temperature value with the set value. The information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the flow of air-conditioning cold water flowing through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value.

[0036] 4) Heating operation mode, including the following steps:

[0037] Step C1: Use the temperature sensor in the control panel to collect the indoor temperature; set the heating operation mode and indoor temperature on the control panel.

[0038] Step C2: The information processing module in the controller adjusts the first regulating valve to a preset state in which the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in an open state; the fan is running, and the indoor return air enters the box through the return air inlet provided on the box, is heated by the first heat exchange zone and the second heat exchange zone of the dual-zone coil, and is then delivered through the air supply outlet provided on the box.

[0039] Step C3: The information processing module in the controller automatically compares the measured indoor temperature value with the set value. The information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the flow of air-conditioning hot water flowing through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value.

[0040] 5) Duty heating operation mode, including the following steps:

[0041] Step 1: Use the temperature sensor in the control panel to collect the indoor temperature; set the on-duty heating operation mode on the control panel, and the default setting value of the indoor temperature system is 5℃.

[0042] Step 2: The information processing module in the controller adjusts the first regulating valve to the preset state where the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in the open state; the fan is running, and the indoor return air enters the box through the return air inlet provided on the box, is heated by the first heat exchange zone and the second heat exchange zone of the dual-zone coil, and is then sent out through the air supply outlet provided on the box.

[0043] Step 3: The controller information processing module automatically compares the measured indoor temperature value with the system default value, and automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the flow of air-conditioning hot water flowing through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value of 5°C.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1) The fan coil unit of the present invention adopts a dual-condition coil, which replaces the coil in the ordinary fan coil with a dual-condition coil. The dual-condition coil consists of a dual-zone coil and a valve assembly. The dual-zone coil is provided with a first heat exchange zone and a second heat exchange zone. The first heat exchange zone and the second heat exchange zone are connected by the valve assembly. Through the adjustment of the valve assembly, during cooling, the cold water flowing through the first heat exchange zone of the dual-zone coil can flow through the second heat exchange zone of the dual-zone coil in whole, in part, or not at all, so that the first heat exchange zone of the dual-zone coil operates under wet conditions to adjust the temperature and humidity of the indoor return air, and the second heat exchange zone operates under wet and dry conditions to adjust the temperature of the indoor return air. Low-temperature cold water can be used for water supply to achieve dual adjustment of the supply air temperature and humidity.

[0046] 2) The fan coil unit of the present invention adopts a dual-mode coil. The water inlet of the second heat exchange zone of the dual-mode coil is the water outlet of the first heat exchange zone. Therefore, compared with the ordinary fan coil, the supply and return water temperature difference is increased, the flow rate of hot and cold water for air conditioning is reduced, and the energy consumption of the air conditioning water distribution system is greatly reduced.

[0047] 3) The present invention provides a control method for a fan coil unit using a dual-condition coil, which can automatically calculate the outlet air temperature of the first heat exchange zone of the dual-condition coil and the unit supply air temperature by setting the indoor temperature and indoor relative humidity, collect the outlet air temperature and the unit supply air temperature of the first heat exchange zone of the dual-condition coil, and the first regulating valve can adjust the air conditioning hot and cold water flow of the first heat exchange zone of the dual-condition coil, and the second regulating valve can adjust the air conditioning hot and cold water flow of the second heat exchange zone of the dual-condition coil, and can realize multiple operating modes including temperature and humidity dual-control cooling operation mode, low-temperature cold water cooling and anti-condensation operation mode, normal temperature cold water cooling operation mode, heating operation mode, on-duty heating operation mode and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 The figure is a schematic structural diagram of a horizontal fan coil unit using a dual-mode coil according to an embodiment of the present invention.

[0049] Figure 2 The figure is a schematic structural diagram of a vertical fan coil unit using a dual-mode coil according to an embodiment of the present invention.

[0050] Figure 3 Schematic diagram of the structure of the dual-mode coil according to an embodiment of the present invention.

[0051] Figure 4 This is a front view of a dual-mode coil according to an embodiment of the present invention.

[0052] Figure 5 This is a side view of a dual-mode coil according to an embodiment of the present invention.

[0053] Figure 6 This is a schematic diagram of a control system for a fan coil unit using a dual-mode coil according to an embodiment of the present invention.

[0054] Figure markings: 100. Dual-zone coil; 111. Water inlet connector; 112. Water outlet connector; 120. Collecting pipe; 130. Water distribution pipe; 140. Collecting pipe; 151. Heat exchange tube; 152. U-shaped tube; 160. Fin; 170. First heat exchange zone; 180. Second heat exchange zone; 191. Left guard plate; 192. Right guard plate; 200. Valve assembly; 210. First regulating valve; 220. First connecting pipe; 230. Second connecting pipe; 240. Third connecting pipe; 300. Fan; 400. Box; 410. Return air outlet; 420. Supply air outlet; 500. Condensate tray; 510. Condensate interface; 610. Controller; 620. Control panel; 630. First temperature sensor; 640. Second temperature sensor; 650. Second regulating valve. DETAILED DESCRIPTION

[0055] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention may be combined accordingly, provided that there is no conflict between them.

[0056] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0057] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0058] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0059] Example

[0060] like Figure 1-6As shown, a fan coil unit using a dual-mode coil specifically includes a dual-mode coil, a fan 300, a box 400 and a condensate tray 500. The box 400 is provided with a return air inlet 410 and an air supply inlet 420. The fan 300 and the dual-mode coil are arranged in the box 400, and the bottom of the dual-mode coil is placed in the condensate tray 500. The dual-mode coil consists of a dual-zone coil 100 and a valve assembly 200. The dual-zone coil 200 is provided with a first heat exchange area 170 and a second heat exchange area 180. The first heat exchange area 170 and the second heat exchange area 180 are connected by the valve assembly 200. Through the connection and regulation of the valve assembly 200, the air-conditioning hot and cold water flowing through the first heat exchange area 170 of the dual-zone coil 100 can flow through the second heat exchange area 180 of the dual-zone coil 100 in whole, in part, or not at all, so that the first heat exchange area 170 of the dual-zone coil 100 operates under wet conditions and the second heat exchange area 180 operates under dry conditions during cooling. Indoor return air enters the box body 400 through the return air inlet 410 provided on the box body 400, is pressurized by the fan 300, and is cooled or heated by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-zone coil 100, and is then sent out through the air supply port 420 provided on the box body 400. During cooling, the condensed water generated by the dual-mode coil flows into the condensate pan 500 and is discharged through the condensed water interface 510.

[0061] Furthermore, the double-zone coil 100 adopts a fin heat exchanger structure, including a water supply joint 111, a water outlet joint 112, a water collecting pipe 120, a water distribution pipe 130, a water collecting pipe 140, a heat exchange tube 151, a U-shaped tube 152, and a fin 160; wherein, the water supply joint 111, the water collecting pipe 120, a plurality of rows of U-shaped coils arranged between the water supply joint 111 and the water collecting pipe 120, and a plurality of fins 160 arranged in parallel at approximately equal distances constitute a first heat exchange zone 170, which is located at the lower part of the double-zone coil 100. The U-shaped coil of the first heat exchange zone 170 is formed by a plurality of heat exchange tubes 151 and a plurality of U-shaped tubes 152 connected end to end in an interlaced manner. One end of the U-shaped coil is connected to the water supply joint 111, and the other end of the U-shaped coil is connected to the water collecting pipe 120; the water distribution pipe 130, the water collecting pipe 140, the heat exchange tube 151, the U-shaped tube 152, and the fin 160 are connected to the water supply joint 111. The tube 140, multiple rows of U-shaped coils arranged between the water distribution pipe 130 and the water collection pipe 140, and multiple fins 160 arranged in parallel at approximately equal distances constitute the second heat exchange zone 180, which is located on the upper part of the double-partitioned coil 100. The U-shaped coil of the second heat exchange zone 180 is also composed of multiple heat exchange tubes 151 and multiple U-shaped tubes 152 connected end to end in sequence. One end of the U-shaped coil is connected to the water distribution pipe 130, and the other end of the U-shaped coil is connected to the water collection pipe 140; the multiple fins 160 of the first heat exchange zone 170 and the second heat exchange zone 180 of the double-partitioned coil 100 are connected in sequence to form a fluid channel for airflow to pass through. The air-conditioning cold water flowing in the heat exchange tube 151 cools the air flowing between the fins 160, and the air-conditioning hot water flowing in the heat exchange tube 151 heats the air flowing between the fins 160.

[0062] Furthermore, the water collecting pipe 120 is provided with a first water outlet interface, the water branch pipe 130 is provided with a second water inlet interface, the water collecting pipe 140 is provided with a second water outlet interface and a water collecting interface, and the second water outlet interface is connected to the water outlet joint 112; the air-conditioning cold and hot water flows evenly into each U-shaped coil of the first heat exchange area 170 through the opening on the water inlet joint 111, and the air-conditioning cold and hot water flowing through each U-shaped coil is collected into the water collecting pipe 120 through the opening on the water collecting pipe 120, and flows out from the first water outlet interface on the water collecting pipe 120; the air-conditioning cold and hot water flows from the second water inlet interface into the water branch pipe 130, and flows evenly into each U-shaped coil of the second heat exchange area 180 through the opening of the water branch pipe 130, and the air-conditioning cold and hot water flowing through each U-shaped coil flows into the water collecting pipe 140 through the opening on the water collecting pipe 140, and flows out from the water outlet joint 112 connected to the water collecting pipe 140.

[0063] Furthermore, the dual-zone coil 100 is further provided with a left guard plate 191 and a right guard plate 192 ; the left guard plate 191 and the right guard plate 192 are formed by bending and are provided on the periphery of the fin 160 .

[0064] Specifically, the water collecting pipe 120, water distribution pipe 130, water collecting pipe 140, heat exchange tube 151, and U-shaped tube 152 are all copper tubes, and the fins 160 are aluminum fins. Fins 160 are uniformly provided with multiple holes of equal size, through which fins 160 are mounted on heat exchange tubes 151. Fins 160 are expanded onto heat exchange tubes 151 using a tube expander, achieving heat conduction and heat exchange with heat exchange tubes 151.

[0065] Furthermore, the dual-zone coil 100 may adopt one of two rows of tubes, three rows of tubes, and four rows of tubes, and the area ratio of the first heat exchange zone 170 to the second heat exchange zone 180 is between 2:1 and 5:1.

[0066] Furthermore, the valve assembly 200 includes a first regulating valve 210 and one, two or all of the first connecting pipe 220, the second connecting pipe 230 and the third connecting pipe 240. The first regulating valve 210 adopts an electric three-way regulating valve. The water collecting pipe 120 of the first heat exchange zone 170 of the dual-zone coil 100 is connected to the water distribution pipe 130 of the second heat exchange zone 170 through the valve assembly 200. At the same time, the water collecting pipe 120 of the first heat exchange zone 170 is connected to the water collecting pipe 140 of the second heat exchange zone 180 through the valve assembly 200. The specific connection method is that one end of the first connecting pipe 220 of the valve assembly 200 is connected to the first water outlet interface on the water collecting pipe 120, and the other end of the first connecting pipe 220 is connected to the inlet of the DC branch of the first regulating valve 210, or the valve assembly 200 The inlet of the DC branch of the first regulating valve 210 is directly connected to the first water outlet interface on the water collecting pipe 120; one end of the second connecting pipe 230 of the valve assembly 200 is connected to the outlet of the DC branch of the first regulating valve 210, and the other end of the second connecting pipe 230 is connected to the second water inlet interface on the water distribution pipe 130, or, the outlet of the DC branch of the first regulating valve 210 of the valve assembly 200 is directly connected to the second water inlet interface on the water distribution pipe 130; one end of the third connecting pipe 240 of the valve assembly 200 is connected to the bypass branch of the first regulating valve 210, and the other end of the third connecting pipe 240 is connected to the water collection interface on the water collection pipe 140, or, the bypass branch of the first regulating valve 210 of the valve assembly 200 is directly connected to the water collection interface on the water collection pipe 140.

[0067] Furthermore, the fan 300 is a cross-flow fan, and the motor of the fan 300 can be a brushless DC motor, which can be powered by 48V DC.

[0068] like Figure 1 The figure shows a specific embodiment of a fan coil unit using a dual-mode coil unit. It is horizontally mounted, with the air supply port 420 located at the front of the housing 400 and the return air port 410 located at the rear or lower rear portion of the housing 400. When pressure-delivery is used for gas delivery, the fan 300 is located behind the dual-mode coil unit. When suction-delivery is used for gas delivery, the fan 300 is located in front of the dual-mode coil unit. The remaining configuration remains the same as above.

[0069] like Figure 2 FIG. 4 shows another embodiment of a fan coil unit using a dual-mode coil unit. The unit is vertically mounted, with the air supply port 420 located at the top of the housing 400 and the air return port 410 located at the bottom. When pressure-delivery is used for gas delivery, the fan 300 is located below the dual-mode coil unit. When suction-delivery is used for gas delivery, the fan 300 is located above the dual-mode coil unit. The remaining configuration remains the same as above.

[0070] like Figure 6 As shown, this embodiment further includes a controller 610, a control panel 620, a first temperature sensor 630, a second temperature sensor 640, and a second regulating valve 650. The first temperature sensor 630 is located at the outlet of the first heat exchange zone 170 of the dual-zone coil 100 and is used to collect the dry-bulb temperature of the outlet air from the first heat exchange zone 170 of the dual-mode coil. The second temperature sensor 640 is located in the air supply port 420 of the housing 400 and is used to collect the dry-bulb temperature of the supply air. The second regulating valve 650 is an electric two-way regulating valve and is used to adjust the flow rate of the air-conditioning hot and cold water flowing through the first heat exchange zone 170 of the dual-mode coil. Figure 6 T in denoted by numeral 620 represents a temperature sensor in the control panel 620 , H represents a humidity sensor in the control panel 620 , T1 represents a first temperature sensor 630 , and T2 represents a second temperature sensor 640 .

[0071] Furthermore, the controller 610 is internally provided with a computing module and an information processing module, and the computing module and the information processing module are connected in a communication manner. The controller 610 is connected to the control panel 620 through a stepless point communication interface of a twisted pair. The controller 610 is provided with multiple I / O interfaces, which are used to connect to the control panel 620, the first temperature sensor 630, the second temperature sensor 640, the first regulating valve 210, the second regulating valve 650 and the fan 300 respectively; the control panel 620 is provided with a display screen and operation buttons, and the control panel 620 is provided with a temperature sensor and a humidity sensor for collecting the indoor temperature and the indoor relative humidity, and displaying the indoor temperature and the indoor relative humidity at the same time. The indoor temperature and the indoor relative humidity can be set through the control panel 620.

[0072] Furthermore, the controller 610 controls the opening and closing states of the DC branch and the bypass branch of the first regulating valve 210 according to the set parameters of the on-site control panel 620, thereby realizing conversion between different operating modes; the controller 610 is equipped with an information processing module, and according to the set indoor temperature and indoor relative humidity, the information processing module in the controller 610 automatically compares the measured values and set values of the indoor temperature and relative humidity, and automatically controls the opening of the DC branch and the bypass branch of the first regulating valve 210, the opening of the second regulating valve 650, and the speed of the fan 300, and sequentially adjusts the flow of hot and cold air conditioning water in the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and the air volume of the fan 300, so as to achieve the purpose of regulating the indoor temperature and humidity.

[0073] See also Figure 6The present invention provides a control method for a fan coil unit using a dual-mode coil unit. The control method is implemented in a fan coil unit using a dual-mode coil unit in this embodiment. The control method includes a temperature and humidity dual-control cooling operation mode, a low-temperature chilled water cooling operation mode with anti-condensation, a normal-temperature chilled water cooling operation mode, a heating operation mode, and a duty heating operation mode. The specific operation modes are described as follows:

[0074] 1) When the air conditioning cold water uses low-temperature cold water below 7°C and normal temperature cold water above 7°C, and there is a humidity control requirement, the temperature and humidity dual control cooling operation mode can be adopted, including the following steps:

[0075] Step S1: Use the temperature sensor and humidity sensor in the control panel 620 to collect the indoor temperature and indoor relative humidity; use the first temperature sensor 630 to collect the outlet dry bulb temperature of the first heat exchange zone 170 of the dual-mode coil; use the second temperature sensor 640 to collect the supply air dry bulb temperature; set the temperature and humidity dual-control cooling operation mode, indoor temperature and indoor relative humidity on the control panel 620.

[0076] Step S2: Based on the set indoor temperature and indoor relative humidity, the calculation module in the controller 610 calculates the indoor dew point temperature and indoor wet-bulb temperature according to the enthalpy-humidity diagram; the information processing module in the controller 610 receives the indoor dew point temperature and indoor wet-bulb temperature input by the calculation module, sets the preset temperature of the first temperature sensor 630 and the preset temperature of the second temperature sensor 640. Furthermore, the preset temperature of the first temperature sensor 630 is 2°C lower than the calculated indoor wet-bulb temperature, and the preset temperature of the second temperature sensor 640 is 2°C higher than the calculated indoor dew point temperature.

[0077] Step S3: The information processing module in the controller 610 partially opens the DC branch of the first regulating valve 210, opens the bypass branch in inverse proportion, and opens the second regulating valve 650 to the preset state; the fan 300 is running, and the indoor return air enters the box body 400 through the return air inlet 410 provided on the box body 400, is cooled by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and is then sent out through the air supply outlet 420 provided on the box body 400.

[0078] Step S4: The information processing module in the controller 610 automatically compares the actual measured value of the first temperature sensor 630 with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve 210, reduces or increases the cold water flow flowing through the second heat exchange area 180 of the dual-mode coil, until the actual measured value of the first temperature sensor 630 reaches the preset temperature; at the same time, the information processing module of the controller 610 automatically compares the actual measured value of the indoor temperature with the set value, and the information processing module in the controller 610 automatically adjusts the opening of the second regulating valve 650 and the speed of the fan 300, adjusts the air-conditioning cold water flow flowing through the first heat exchange area 170 of the dual-mode coil and / or adjusts the air volume of the fan 300, until the indoor temperature and relative humidity reach the set value, and makes the supply air temperature higher than the indoor dew point temperature by 2°C to ensure that the supply air does not condense.

[0079] 2) When the air conditioning cold water uses low-temperature cold water with a temperature below 7°C and there is no humidity control requirement, the low-temperature cold water cooling and anti-condensation operation mode can be adopted, including the following steps:

[0080] Step A1: Use the temperature and humidity sensors in the control panel 620 to collect the indoor temperature and indoor relative humidity; use the first temperature sensor 630 to collect the outlet dry-bulb temperature of the first heat exchange zone 170 of the dual-zone coil 100; use the second temperature sensor 640 to collect the supply air dry-bulb temperature; set the temperature and humidity dual-control cooling operation mode and indoor temperature on the control panel 620, and the system default value of the indoor relative humidity is 60%.

[0081] Step A2: Based on the set indoor temperature and the system default value of 60% for the indoor relative humidity, the calculation module in the controller 610 calculates the indoor dew point temperature and the indoor wet-bulb temperature according to the psychrometric diagram; the information processing module in the controller 610 receives the indoor dew point temperature and the indoor wet-bulb temperature input by the calculation module, sets the preset temperature of the first temperature sensor 630 and the preset temperature of the second temperature sensor 640, and further, the preset temperature of the first temperature sensor 630 is 2°C lower than the calculated indoor wet-bulb temperature, and the preset temperature of the second temperature sensor 640 is 2°C higher than the calculated indoor dew point temperature.

[0082] Step A3: The information processing module in the controller 610 partially opens the DC branch of the first regulating valve 210, opens the bypass branch in inverse proportion, and opens the second regulating valve 650 to the preset state; the fan 300 is running, and the indoor return air enters the box body 400 through the return air inlet 410 provided on the box body 400, is cooled by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and is then sent out through the air supply outlet 420 provided on the box body 400.

[0083] Step A4: The information processing module of the controller 610 automatically compares the actual measured value of the first temperature sensor 630 with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve 210, and reduces or increases the air-conditioning cold water flow flowing through the second heat exchange zone 180 of the dual-mode coil until the actual measured value of the first temperature sensor 630 reaches the preset temperature; at the same time, the information processing module in the controller 610 automatically compares the actual measured value of the indoor temperature with the set value, and the information processing module in the controller 610 automatically adjusts the opening of the second regulating valve 650 and the speed of the fan 300, adjusts the air-conditioning cold water flow flowing through the first heat exchange zone 170 of the dual-zone coil 200 and / or adjusts the air volume of the fan 300 until the indoor temperature reaches the set value, the indoor relative humidity reaches the system default value of 60%, and the supply air temperature is made 2°C higher than the indoor dew point temperature to ensure that the supply air does not condense.

[0084] 3) When the air conditioning cold water uses a temperature higher than 7°C and there is no humidity control requirement, the normal temperature cold water cooling operation mode can be adopted, including the following steps:

[0085] Step B1: Use the temperature sensor in the control panel 620 to collect the indoor temperature; set the normal temperature cold water cooling operation mode and the indoor temperature on the control panel 620.

[0086] Step B2: The information processing module in the controller 610 adjusts the first regulating valve 210 to a preset state in which the bypass branch is fully open, the DC branch is closed, and the second regulating valve 650 is open; the fan 300 is running, and the indoor return air enters the box body 400 through the return air port 410 provided on the box body 400, is cooled by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and is then delivered out through the air supply port 420 provided on the box body 400.

[0087] Step B3: The information processing module of the controller 610 automatically compares the actual indoor temperature value with the set value. The information processing module of the controller 610 automatically adjusts the opening of the second regulating valve 650 and the speed of the fan 300, adjusts the flow of cold water flowing through the dual-mode coil and / or adjusts the air volume of the fan 300 until the indoor temperature reaches the set value.

[0088] 4) Heating operation mode, including the following steps:

[0089] Step C1: Use the temperature sensor in the control panel 620 to collect the indoor temperature; set the heating operation mode and indoor temperature on the control panel 620.

[0090] Step C2: The information processing module in the controller 610 adjusts the first regulating valve 210 to a preset state in which the bypass branch is fully open, the DC branch is closed, and the second regulating valve 650 is open; the fan 300 is running, and the indoor return air enters the box body 400 through the return air inlet 410 provided on the box body 400, is heated by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and is then delivered through the air supply outlet 420 provided on the box body 400.

[0091] Step C3: The information processing module in the controller 610 automatically compares the measured indoor temperature value with the set value. The information processing module in the controller 610 automatically adjusts the opening of the second regulating valve 650 and the speed of the fan 300, adjusts the flow of hot water flowing through the dual-mode coil and / or adjusts the air volume of the fan 300 until the indoor temperature reaches the set value.

[0092] 5) Duty heating operation mode, including the following steps:

[0093] Step 1: Use the temperature sensor in the control panel 620 to collect the indoor temperature; set the on-duty heating operation mode on the control panel 620, and the system default indoor temperature setting value is 5°C.

[0094] Step 2: The information processing module in the controller 610 adjusts the first regulating valve 210 to the preset state in which the bypass branch is fully open, the DC branch is closed, and the second regulating valve 650 is open; the fan 300 is running, and the indoor return air enters the box body 400 through the return air inlet 410 provided on the box body 400, is heated by the first heat exchange zone 170 and the second heat exchange zone 180 of the dual-mode coil, and is then delivered through the air supply outlet 420 provided on the box body 400.

[0095] Step 3: The information processing module in the controller 610 automatically compares the actual indoor temperature value with the system default value. The information processing module in the controller 610 automatically adjusts the opening of the second regulating valve 650 and the speed of the fan 300, adjusts the flow of hot water flowing through the dual-mode coil and / or adjusts the air volume of the fan 300 until the indoor temperature reaches the set value of 5°C.

[0096] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A fan coil unit using a dual-mode coil, characterized in that: The air conditioner comprises a dual-mode coil, a fan, a condensate pan and a housing. The housing is provided with a return air inlet and an air supply inlet. The fan and the dual-mode coil are arranged in the housing, and the bottom of the dual-mode coil is placed in the condensate pan. The dual-mode coil consists of a dual-zone coil and a valve assembly. The dual-zone coil is provided with a first heat exchange area and a second heat exchange area. The first heat exchange area and the second heat exchange area are connected by a valve assembly. Through the adjustment of the valve assembly, the air-conditioning hot and cold water flowing through the first heat exchange area of the dual-zone coil flows entirely, partially or not through the second heat exchange area of the dual-zone coil. When cooling is achieved, the first heat exchange area of the dual-zone coil operates under wet conditions and the second heat exchange area operates under dry conditions. After the fan is running, indoor return air enters the housing through the return air inlet provided on the housing, is cooled or heated by the first heat exchange area and the second heat exchange area of the dual-zone coil, and is then sent out through the air supply inlet provided on the housing. During cooling, the condensed water generated by the dual-mode coil flows into the condensate pan and is discharged through the condensed water interface.

2. A fan coil unit using a dual-mode coil according to claim 1, characterized in that: The double-zone coil includes a water supply joint, a water outlet joint, a water collecting pipe, a water distribution pipe, a water collection pipe, a heat exchange pipe, a U-shaped pipe, and a fin; wherein the water supply joint, the water collection pipe, multiple rows of U-shaped coils arranged between the water supply joint and the water collection pipe, and multiple parallel arranged fins constitute the first heat exchange zone, which is located at the lower part of the double-zone coil. The U-shaped coil in the first heat exchange zone is formed by multiple heat exchange pipes and multiple U-shaped pipes connected end to end in sequence. One end of the U-shaped coil is connected to the water supply joint, and the other end of the U-shaped coil is connected to the water collection pipe; the water distribution pipe, the water collection pipe, and the heat exchange pipes arranged between the water distribution pipe and the water collection pipe The second heat exchange zone is composed of multiple rows of U-shaped coils and multiple parallel fins, which are located on the upper part of the double-partition coil. The U-shaped coil in the second heat exchange zone is also composed of multiple heat exchange tubes and multiple U-shaped tubes connected end to end in sequence. One end of the U-shaped coil is connected to the water distribution pipe, and the other end of the U-shaped coil is connected to the water collection pipe; the multiple fins in the first heat exchange zone and the second heat exchange zone of the double-partition coil are connected in sequence to form a fluid channel for airflow to pass through. The air-conditioning cold water flowing in the heat exchange tubes cools the air flowing between the fins, and the air-conditioning hot water flowing in the heat exchange tubes heats the air flowing between the fins.

3. A fan coil unit using a dual-mode coil according to claim 2, characterized in that: The collecting pipe is provided with a first water outlet interface, the water branch pipe is provided with a second water inlet interface, the collecting pipe is provided with a second water outlet interface and a collecting pipe interface, and the second water outlet interface is connected to the water outlet joint; the air-conditioning cold and hot water flows evenly into each U-shaped coil in the first heat exchange area through the opening on the water inlet joint, and the air-conditioning cold and hot water flowing through each U-shaped coil is collected into the collecting pipe through the opening on the collecting pipe, and flows out from the first water outlet interface on the collecting pipe; the air-conditioning cold and hot water flows into the water branch pipe from the second water inlet interface, and flows evenly into each U-shaped coil in the second heat exchange area through the opening of the water branch pipe, and the air-conditioning cold and hot water flowing through each U-shaped coil flows into the collecting pipe through the opening on the collecting pipe, and flows out from the water outlet joint connected to the collecting pipe.

4. A fan coil unit using a dual-mode coil according to claim 2, characterized in that: The dual-zone coil is further provided with a left guard plate and a right guard plate; the left guard plate and the right guard plate are formed by bending and are arranged on the periphery of the fin; the water collecting pipe, the water distribution pipe, the water collecting pipe, the heat exchange tube, and the U-shaped tube are all made of copper tubes, and the fins are made of aluminum fins; a plurality of tube holes of the same size are evenly opened on the fins, and the fins are installed on the heat exchange tubes through the tube holes. The fins are expanded and connected to the heat exchange tubes by a tube expander to achieve heat conduction and heat exchange with the heat exchange tubes; the dual-zone coil adopts any one of two rows of tubes, three rows of tubes, and four rows of tubes, and the area ratio of the first heat exchange zone to the second heat exchange zone is between 2:1 and 5:

1.

5. The fan coil unit using a dual-mode coil according to claim 3, characterized in that: The valve assembly includes a first regulating valve and one, two or all of the first connecting pipe, the second connecting pipe and the third connecting pipe. The first regulating valve adopts an electric three-way regulating valve; the water collecting pipe of the first heat exchange area of the double-zone coil is connected with the water distribution pipe of the second heat exchange area through the valve assembly, and at the same time, the water collecting pipe of the first heat exchange area is connected with the water collecting pipe of the second heat exchange area through the valve assembly; the specific connection method is that one end of the first connecting pipe of the valve assembly is connected with the first water outlet interface on the water collecting pipe, and the other end of the first connecting pipe is connected with the inlet of the DC branch of the first regulating valve, or the DC branch of the first regulating valve of the valve assembly is connected with the DC branch of the first regulating valve of the valve assembly. The inlet of the flow branch is directly connected to the first water outlet interface on the water collecting pipe; one end of the second connecting pipe of the valve assembly is connected to the outlet of the DC branch of the first regulating valve, and the other end of the second connecting pipe is connected to the second water inlet interface on the water distribution pipe, or, the outlet of the DC branch of the first regulating valve of the valve assembly is directly connected to the second water inlet interface on the water distribution pipe; one end of the third connecting pipe of the valve assembly is connected to the bypass branch of the first regulating valve, and the other end of the third connecting pipe is connected to the water collection interface on the water collection pipe, or, the bypass branch of the first regulating valve of the valve assembly is directly connected to the water collection interface on the water collection pipe.

6. The fan coil unit using a dual-mode coil according to claim 1, wherein the fan is a cross-flow fan, the fan motor is a brushless DC motor, and is powered by 48V DC.

7. The fan coil unit using a dual-mode coil according to claim 1, characterized in that: When the fan coil unit is installed horizontally, the air supply port is located at the front end of the box, and the return air port is located at the rear end of the box or the lower rear part of the box. When the gas delivery method is pressure delivery, the fan is located behind the dual-condition coil. When the gas delivery method is suction delivery, the fan is located in front of the dual-condition coil. When the unit is installed vertically, the air supply port is located at the top of the box, and the return air port is located at the bottom of the box. When the gas delivery method is pressure delivery, the fan is located above the dual-condition coil. When the gas delivery method is pressure delivery, the fan is located above the dual-condition coil.

8. The fan coil unit using a dual-mode coil according to claim 1, characterized in that: A controller, a control panel, a first temperature sensor, a second temperature sensor, and a second regulating valve are also provided; the first temperature sensor is arranged at the air outlet of the first heat exchange zone of the dual-mode coil, and is used to collect the dry-bulb temperature of the outlet air of the first heat exchange zone; the second temperature sensor is arranged in the air supply port of the box, and is used to collect the dry-bulb temperature of the supply air; the second regulating valve adopts an electric two-way regulating valve, which is used to adjust the flow of air-conditioning hot and cold water flowing through the first heat exchange zone of the dual-mode coil.

9. The fan coil unit using a dual-mode coil according to claim 8, characterized in that: The controller is provided with a computing module and an information processing module, the computing module and the information processing module are connected in a communication manner, the controller and the control panel are connected via a twisted pair stepless point communication interface, the controller is provided with multiple I / O interfaces for connecting to the control panel, the first temperature sensor, the second temperature sensor, the first regulating valve, the second regulating valve and the fan respectively; the control panel is provided with a display screen and operation buttons, the control panel is provided with a temperature sensor and a humidity sensor for collecting indoor temperature and relative humidity, and displaying the indoor temperature and relative humidity at the same time, and the indoor temperature and relative humidity can be set through the control panel degree; the controller controls the opening and closing states of the DC branch and the bypass branch of the first regulating valve according to the operating mode set by the on-site control panel to realize the conversion of different operating modes; the controller is equipped with an information processing module. According to the set indoor temperature and indoor relative humidity, the information processing module in the controller automatically compares the measured values and the set values of the indoor temperature and relative humidity, and automatically controls the opening of the DC branch and the bypass branch of the first regulating valve, the opening of the second regulating valve, and the speed of the fan, and sequentially adjusts the air conditioning hot and cold water flow and the fan air volume flowing through the first heat exchange zone and the second heat exchange zone of the dual-mode coil to achieve the purpose of regulating indoor temperature and humidity.

10. A control method for a fan coil unit using a dual-mode coil, applied to a fan coil unit using a dual-mode coil according to any one of claims 1 to 9, characterized in that: The control methods include temperature and humidity dual-control cooling operation mode, low-temperature cold water cooling and anti-condensation operation mode, normal temperature cold water cooling operation mode, heating operation mode, and duty heating operation mode. The operation modes are described as follows: 1) When the air conditioning cold water uses low-temperature cold water with a temperature below 7°C and normal temperature cold water above 7°C, and there is a humidity control requirement, the temperature and humidity dual control cooling operation mode is adopted, including the following steps: Step S1: Using the temperature sensor and humidity sensor in the control panel to collect the indoor temperature and indoor relative humidity; using the first temperature sensor to collect the outlet dry-bulb temperature of the first heat exchange zone of the dual-mode coil; using the second temperature sensor to collect the supply air dry-bulb temperature; setting the temperature and humidity dual-control cooling operation mode, indoor temperature, and indoor relative humidity on the control panel; Step S2: Based on the set indoor temperature and indoor relative humidity, the calculation module in the controller calculates the dew point temperature and wet bulb temperature according to the psychrometric diagram; the information processing module in the controller receives the dew point temperature and wet bulb temperature input by the calculation module, and sets the preset temperature of the first temperature sensor and the preset temperature of the second temperature sensor, wherein the preset temperature of the first temperature sensor is 2°C lower than the calculated wet bulb temperature, and the preset temperature of the second temperature sensor is 2°C higher than the calculated dew point temperature; Step S3: The information processing module within the controller partially opens the DC branch of the first regulating valve and opens the bypass branch in inverse proportion, with the second regulating valve in a preset open state. The fan is running, and indoor return air enters the box through the return air inlet provided on the box body, is cooled by the first and second heat exchange zones of the dual-mode coil, and is then delivered out through the air supply outlet provided on the box body. Step S4: The information processing module in the controller automatically compares the measured value of the first temperature sensor with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve, and reduces or increases the air conditioning cold water flow through the second heat exchange zone of the dual-mode coil until the measured value of the first temperature sensor reaches the preset temperature; at the same time, the information processing module in the controller automatically compares the measured value of the indoor temperature with the set value, and the information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the air conditioning cold water flow through the first heat exchange zone of the dual-mode coil and / or adjusts the air volume of the fan until the indoor temperature and relative humidity reach the set values, and the supply air temperature is set to be 2°C higher than the indoor dew point temperature to ensure that the supply air does not condense; 2) When the air conditioning cold water uses low-temperature cold water with a temperature below 7°C and there is no humidity control requirement, the low-temperature cold water cooling and anti-condensation operation mode is adopted, including the following steps: Step A1: Use the temperature and humidity sensors in the control panel to collect indoor temperature and relative humidity. Use the first temperature sensor to collect the outlet dry-bulb temperature of the first heat exchange zone of the dual-mode coil. Use the second temperature sensor to collect the supply dry-bulb temperature. Set the low-temperature chilled water cooling and anti-condensation operation mode, indoor temperature, and indoor relative humidity to the default value of 60% on the control panel. Step A2: Based on the set indoor temperature and the system default value of the indoor relative humidity of 60%, the calculation module in the controller calculates the indoor dew point temperature and the indoor wet-bulb temperature according to the psychrometric diagram; the information processing module in the controller receives the indoor dew point temperature and the indoor wet-bulb temperature input by the calculation module, and sets the preset temperature of the first temperature sensor and the preset temperature of the second temperature sensor, wherein the preset temperature of the first temperature sensor is 2°C lower than the calculated indoor wet-bulb temperature, and the preset temperature of the second temperature sensor is 2°C higher than the calculated indoor dew point temperature; Step A3: The information processing module within the controller partially opens the DC branch of the first regulating valve and inversely opens the bypass branch, with the second regulating valve in the preset open state. The fan operates, and indoor return air enters the cabinet through the return air inlet provided on the cabinet. After being cooled by the first and second heat exchange zones of the dual-mode coil, it is delivered out through the supply air inlet provided on the cabinet. Step A4: The information processing module within the controller automatically compares the measured value of the first temperature sensor with the preset temperature, automatically adjusts the opening of the bypass branch of the first regulating valve, and reduces or increases the air conditioning cold water flow through the second heat exchange zone of the dual-mode coil until the measured value of the first temperature sensor reaches the preset temperature. At the same time, the information processing module within the controller automatically compares the measured value of the indoor temperature with the set value, and automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusting the air conditioning cold water flow through the first heat exchange zone of the dual-mode coil and / or adjusting the air volume of the fan until the indoor temperature reaches the set value, the indoor relative humidity reaches the system default value of 60%, and the supply air temperature is set to 2°C higher than the indoor dew point temperature to ensure that the supply air does not condense. 3) When the air conditioning cold water uses a temperature higher than 7°C and there is no humidity control requirement, the normal temperature cold water cooling operation mode can be adopted, including the following steps: Step B1: Use the temperature sensor in the control panel to collect the indoor temperature; set the normal temperature cold water cooling operation mode and indoor temperature on the control panel; Step B2: The information processing module within the controller adjusts the first regulating valve to a preset state where the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in an open state. The fan is running, and indoor return air enters the cabinet through the return air inlet provided on the cabinet. After being cooled by the first and second heat exchange zones of the dual-mode coil, it is delivered out through the supply air inlet provided on the cabinet. Step B3: The information processing module in the controller automatically compares the measured indoor temperature value with the set value, and automatically adjusts the opening of the second regulating valve and the speed of the fan, thereby adjusting the flow of cold water through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value. 4) Heating operation mode, including the following steps: Step C1: Using the temperature sensor in the control panel to collect the indoor temperature; setting the heating operation mode and indoor temperature on the control panel; Step C2: The information processing module within the controller adjusts the first regulating valve to a preset state where the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in an open state. The fan is running, and indoor return air enters the box through the return air inlet provided on the box body. After being heated by the first and second heat exchange zones of the dual-mode coil, it is delivered through the air supply outlet provided on the box body. Step C3: The information processing module in the controller automatically compares the measured indoor temperature value with the set value, and the controller information processing module automatically adjusts the opening of the second regulating valve and the speed of the fan, thereby adjusting the flow of hot water flowing through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value; 5) Duty heating operation mode, including the following steps: Step 1: Use the temperature sensor in the control panel to collect the indoor temperature; set the on-duty heating operation mode on the control panel, and the default setting value of the indoor temperature system is 5℃; Step 2: The information processing module within the controller adjusts the first regulating valve to a preset state where the bypass branch is fully open, the DC branch is closed, and the second regulating valve is in an open state. The fan is running, and indoor return air enters the box through the return air inlet provided on the box body. After being heated by the first and second heat exchange zones of the dual-mode coil, it is delivered through the air supply outlet provided on the box body. Step 3: The information processing module in the controller automatically compares the measured indoor temperature value with the system default value. The information processing module in the controller automatically adjusts the opening of the second regulating valve and the speed of the fan, adjusts the flow of air-conditioning hot water flowing through the dual-mode coil and the air volume of the fan until the indoor temperature reaches the set value of 5°C.

Images